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David M. Goldenberg - One of the best experts on this subject based on the ideXlab platform.
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Anti-CD22/CD20 Bispecific Antibody with Enhanced Trogocytosis for Treatment of Lupus
2016Co-Authors: Edmund A. Rossi, Chien-hsing Chang, David M. GoldenbergAbstract:The humanized anti-CD22 antibody, epratuzumab, has demonstrated therapeutic activity in clinical trials of lymphoma, leukemia and autoimmune diseases, treating currently over 1500 cases of non-Hodgkin lymphoma, acute lymphoblastic leukemias, Waldenström’s macroglobulinemia, Sjögren’s syndrome, and systemic lupus erythematosus. Because epratuzumab reduces on average only 35 % of circulating B cells in patients, and has minimal antibody-dependent cellular cytotoxicity and negligible complement-dependent cytotoxicity when evaluated in vitro, its therapeutic activity may not result completely from B-cell depletion. We reported recently that epratuzumab mediates Fc/FcR-dependent membrane transfer from B cells to effector cells via trogocytosis, resulting in a substantial reduction of multiple BCR modulators, including CD22, CD19, CD21, and CD79b, as well as key cell adhesion molecules, including CD44, CD62L, and b7 integrin, on the surface of B cells in peripheral blood mononuclear cells obtained from normal donors or SLE patients. Rituximab has clinical activity in lupus, but failed to achieve primary endpoints in a Phase III trial. This is the first study of trogocytosis mediated by bispecific antibodies targeting neighboring cell-surface proteins, CD22, CD20, and CD19, as demonstrated by flow cytometry and immunofluorescence microscopy. We show that, compared to epratuzumab, a bispecific hexavalent antibody comprising epratuzumab and veltuzumab (humanized anti-CD20 mAb) exhibits enhanced trogocytosis resulting in major reductions in B-cell surface levels of CD19, CD20, CD21, CD22, CD79b, CD44, CD62L and b7-integrin, and wit
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Subcutaneous veltuzumab, a humanized anti-CD20 antibody, in the treatment of refractory pemphigus vulgaris.
JAMA dermatology, 2014Co-Authors: Christoph T. Ellebrecht, David M. Goldenberg, Eun J. Choi, David Allman, Donald E. Tsai, William A. Wegener, Aimee S. PayneAbstract:Importance B-cell depletion with the anti-CD20 antibody rituximab is highly effective for pemphigus vulgaris (PV) treatment. However, most patients experience relapse, and intravenous rituximab infusions are expensive. Therefore, cost-effective anti-CD20 therapies are desirable. Observations A compassionate-use investigational new drug protocol was approved to administer veltuzumab, a second-generation humanized anti-CD20 antibody, to a patient with refractory PV. Veltuzumab was administered as two 320-mg (188 mg/m 2 ) subcutaneous doses 2 weeks apart, resulting in complete remission of disease off therapy. The disease relapsed 2 years after treatment. A second cycle of subcutaneous veltuzumab, using the same dosage regimen, again induced complete remission off therapy, which remained at 9 months. No serious adverse events occurred during 35 months of follow-up. Serum veltuzumab levels were 22 and 29 μg/mL 2 weeks after the first dose of each cycle, and the drug remained detectable in the serum for longer than 3 months. Relapse and response to veltuzumab generally correlated with desmoglein 3 enzyme-linked immunosorbent assay index values. Shortly after a relapse that occurred after a long-term remission, the patient demonstrated an elevated naive (CD19 + CD27 − ) to memory (CD19 + CD27 + ) B-cell ratio of 19.5 and transitional (CD19 + CD24 + CD38 + ) B-cell frequency of 12.5%. Conclusions and Relevance Subcutaneous veltuzumab may be a safe, effective, and more economical alternative to intravenous rituximab for PV therapy. Clinical trials of subcutaneous veltuzumab for PV are warranted.
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anti cd22 cd20 bispecific antibody with enhanced trogocytosis for treatment of lupus
PLOS ONE, 2014Co-Authors: Edmund A. Rossi, Chien-hsing Chang, David M. GoldenbergAbstract:The humanized anti-CD22 antibody, epratuzumab, has demonstrated therapeutic activity in clinical trials of lymphoma, leukemia and autoimmune diseases, treating currently over 1500 cases of non-Hodgkin lymphoma, acute lymphoblastic leukemias, Waldenstrom’s macroglobulinemia, Sjogren’s syndrome, and systemic lupus erythematosus. Because epratuzumab reduces on average only 35% of circulating B cells in patients, and has minimal antibody-dependent cellular cytotoxicity and negligible complement-dependent cytotoxicity when evaluated in vitro, its therapeutic activity may not result completely from B-cell depletion. We reported recently that epratuzumab mediates Fc/FcR-dependent membrane transfer from B cells to effector cells via trogocytosis, resulting in a substantial reduction of multiple BCR modulators, including CD22, CD19, CD21, and CD79b, as well as key cell adhesion molecules, including CD44, CD62L, and β7 integrin, on the surface of B cells in peripheral blood mononuclear cells obtained from normal donors or SLE patients. Rituximab has clinical activity in lupus, but failed to achieve primary endpoints in a Phase III trial. This is the first study of trogocytosis mediated by bispecific antibodies targeting neighboring cell-surface proteins, CD22, CD20, and CD19, as demonstrated by flow cytometry and immunofluorescence microscopy. We show that, compared to epratuzumab, a bispecific hexavalent antibody comprising epratuzumab and veltuzumab (humanized anti-CD20 mAb) exhibits enhanced trogocytosis resulting in major reductions in B-cell surface levels of CD19, CD20, CD21, CD22, CD79b, CD44, CD62L and β7-integrin, and with considerably less immunocompromising B-cell depletion that would result with anti-CD20 mAbs such as veltuzumab or rituximab, given either alone or in combination with epratuzumab. A CD22/CD19 bispecific hexavalent antibody, which exhibited enhanced trogocytosis of some antigens and minimal B-cell depletion, may also be therapeutically useful. The bispecific antibody is a candidate for improved treatment of lupus and other autoimmune diseases, offering advantages over administration of the two parental antibodies in combination.
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op0118 epratuzumab mediates bcr antigen trogocytosis as potential mechanism of action in systemic lupus erythematosus sle
Annals of the Rheumatic Diseases, 2013Co-Authors: David M. Goldenberg, Rosana B. Michel, Edmund A. Rossi, Daniel J. Wallace, Chien-hsing ChangAbstract:Background Epratuzumab, a humanized monoclonal antibody targeting CD22, has demonstrated therapeutic activity in clinical trials of patients with SLE, yet an understanding of its mechanism of action (MOA) is still emerging. Because epratuzumab reduces on average 35% of circulating B cells in patients, its therapeutic efficacy involves MOA beyond B-cell depletion. Modulation of CD22 and other surface molecules that regulate B-cell antigen receptor (BCR) signaling may alter B-cell functions and ultimately mitigate symptoms of the underlying disease. Objectives Using an experimental ex-vivo analysis, we identified trogocytosis as a novel MOA for epratuzumab, which may be important for therapy of SLE and other autoimmune disorders. Clinical specimens of SLE patients were evaluated for evidence of trogocytosis induced by epratuzumab in vivo . Methods PBMCs from either healthy donors or SLE patients were incubated with epratuzumab, and the relative surface levels of CD22, CD19, CD21, and CD79b on B cells were analyzed by flow cytometry (FCM). Trogocytosis was studied with FCM and fluorescence microscopy using B-cell NHL cell lines (Daudi and Raji) mixed with PBMCs, T cells, monocytes, or granulocytes. We further measured the relative levels of CD22, CD19, CD21, and CD79b on B cells from five SLE patients who were receiving epratuzumab, four treatment-naive SLE patients, and two receiving belimumab. Results Epratuzumab promptly induced a marked decrease of surface CD22 (>80%), CD19 (>50%), CD21 (>50%), and CD79b (>30%) on B cells in PBMCs obtained from normal donors or treatment-naive SLE patients. CD27 - B cells were more responsive than CD27 + cells. Within a few hrs, B-cell surface proteins were reduced to a similar level over a broad concentration range (0.01 – 100 µg/mL) of epratuzumab. Although some Fc-independent loss of CD22 is expected from internalization, the concurrent and prominent reduction of CD19, CD21, and CD79b is Fc-dependent and results from trogocytosis of epratuzumab-bound B cells to FcgR-expressing effector cells, including monocytes, NK cells, and granulocytes. Reduced staining of surface antigens on B cells coincided with positive CD19 and CD22 staining of the effector cells. Epratuzumab-induced transfer of membrane components from Daudi cells to monocytes was also evident by fluorescence microscopy. Unlike rituximab, which reduced the B-cell count by 50% in the ex-vivo assay, epratuzumab did not cause significant B-cell depletion. Analysis of SLE patient samples suggests that similar epratuzumab-mediated trogocytosis, as observed ex-vivo , also occurs clinically. As expected, CD22 was significantly ( P 80%) on the B cells of epratuzumab-treated patients. Notably, CD19, CD21 and CD79b were each also significantly ( P Conclusions This study revealed a previously unknown, and potentially important, MOA of epratuzumab. The findings of reduced levels of CD19 are of particular relevance for the efficacy of epratuzumab in SLE, because elevated CD19 has been correlated with susceptibility to SLE in animal models as well as in patients, and down-regulation of CD19 should attenuate activation of B cells by raising the BCR signaling threshold. Disclosure of Interest D. Goldenberg Shareholder of: Immunomedics, Inc., Employee of: Immunomedics, Inc., E. Rossi Employee of: Immunomedics, Inc., R. Michel Employee of: Immunomedics, Inc., D. Wallace: None Declared, C.-H. Chang: None Declared
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op0118 epratuzumab mediates bcr antigen trogocytosis as potential mechanism of action in systemic lupus erythematosus sle
Annals of the Rheumatic Diseases, 2013Co-Authors: David M. Goldenberg, Daniel J. Wallace, Edmund A. Rossi, R. Michel, Chien-hsing ChangAbstract:Background Epratuzumab, a humanized monoclonal antibody targeting CD22, has demonstrated therapeutic activity in clinical trials of patients with SLE, yet an understanding of its mechanism of action (MOA) is still emerging. Because epratuzumab reduces on average 35% of circulating B cells in patients, its therapeutic efficacy involves MOA beyond B-cell depletion. Modulation of CD22 and other surface molecules that regulate B-cell antigen receptor (BCR) signaling may alter B-cell functions and ultimately mitigate symptoms of the underlying disease. Objectives Using an experimental ex-vivo analysis, we identified trogocytosis as a novel MOA for epratuzumab, which may be important for therapy of SLE and other autoimmune disorders. Clinical specimens of SLE patients were evaluated for evidence of trogocytosis induced by epratuzumab in vivo . Methods PBMCs from either healthy donors or SLE patients were incubated with epratuzumab, and the relative surface levels of CD22, CD19, CD21, and CD79b on B cells were analyzed by flow cytometry (FCM). Trogocytosis was studied with FCM and fluorescence microscopy using B-cell NHL cell lines (Daudi and Raji) mixed with PBMCs, T cells, monocytes, or granulocytes. We further measured the relative levels of CD22, CD19, CD21, and CD79b on B cells from five SLE patients who were receiving epratuzumab, four treatment-naive SLE patients, and two receiving belimumab. Results Epratuzumab promptly induced a marked decrease of surface CD22 (>80%), CD19 (>50%), CD21 (>50%), and CD79b (>30%) on B cells in PBMCs obtained from normal donors or treatment-naive SLE patients. CD27- B cells were more responsive than CD27+ cells. Within a few hrs, B-cell surface proteins were reduced to a similar level over a broad concentration range (0.01 – 100 µg/mL) of epratuzumab. Although some Fc-independent loss of CD22 is expected from internalization, the concurrent and prominent reduction of CD19, CD21, and CD79b is Fc-dependent and results from trogocytosis of epratuzumab-bound B cells to FcgR-expressing effector cells, including monocytes, NK cells, and granulocytes. Reduced staining of surface antigens on B cells coincided with positive CD19 and CD22 staining of the effector cells. Epratuzumab-induced transfer of membrane components from Daudi cells to monocytes was also evident by fluorescence microscopy. Unlike rituximab, which reduced the B-cell count by 50% in the ex-vivo assay, epratuzumab did not cause significant B-cell depletion. Analysis of SLE patient samples suggests that similar epratuzumab-mediated trogocytosis, as observed ex-vivo , also occurs clinically. As expected, CD22 was significantly ( P 80%) on the B cells of epratuzumab-treated patients. Notably, CD19, CD21 and CD79b were each also significantly ( P <.02) lower for the epratuzumab group. Conclusions This study revealed a previously unknown, and potentially important, MOA of epratuzumab. The findings of reduced levels of CD19 are of particular relevance for the efficacy of epratuzumab in SLE, because elevated CD19 has been correlated with susceptibility to SLE in animal models as well as in patients, and down-regulation of CD19 should attenuate activation of B cells by raising the BCR signaling threshold. Disclosure of Interest D. Goldenberg Shareholder of: Immunomedics, Inc., Employee of: Immunomedics, Inc., E. Rossi Employee of: Immunomedics, Inc., R. Michel Employee of: Immunomedics, Inc., D. Wallace: None Declared, C.-H. Chang: None Declared
Chien-hsing Chang - One of the best experts on this subject based on the ideXlab platform.
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Anti-CD22/CD20 Bispecific Antibody with Enhanced Trogocytosis for Treatment of Lupus
2016Co-Authors: Edmund A. Rossi, Chien-hsing Chang, David M. GoldenbergAbstract:The humanized anti-CD22 antibody, epratuzumab, has demonstrated therapeutic activity in clinical trials of lymphoma, leukemia and autoimmune diseases, treating currently over 1500 cases of non-Hodgkin lymphoma, acute lymphoblastic leukemias, Waldenström’s macroglobulinemia, Sjögren’s syndrome, and systemic lupus erythematosus. Because epratuzumab reduces on average only 35 % of circulating B cells in patients, and has minimal antibody-dependent cellular cytotoxicity and negligible complement-dependent cytotoxicity when evaluated in vitro, its therapeutic activity may not result completely from B-cell depletion. We reported recently that epratuzumab mediates Fc/FcR-dependent membrane transfer from B cells to effector cells via trogocytosis, resulting in a substantial reduction of multiple BCR modulators, including CD22, CD19, CD21, and CD79b, as well as key cell adhesion molecules, including CD44, CD62L, and b7 integrin, on the surface of B cells in peripheral blood mononuclear cells obtained from normal donors or SLE patients. Rituximab has clinical activity in lupus, but failed to achieve primary endpoints in a Phase III trial. This is the first study of trogocytosis mediated by bispecific antibodies targeting neighboring cell-surface proteins, CD22, CD20, and CD19, as demonstrated by flow cytometry and immunofluorescence microscopy. We show that, compared to epratuzumab, a bispecific hexavalent antibody comprising epratuzumab and veltuzumab (humanized anti-CD20 mAb) exhibits enhanced trogocytosis resulting in major reductions in B-cell surface levels of CD19, CD20, CD21, CD22, CD79b, CD44, CD62L and b7-integrin, and wit
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anti cd22 cd20 bispecific antibody with enhanced trogocytosis for treatment of lupus
PLOS ONE, 2014Co-Authors: Edmund A. Rossi, Chien-hsing Chang, David M. GoldenbergAbstract:The humanized anti-CD22 antibody, epratuzumab, has demonstrated therapeutic activity in clinical trials of lymphoma, leukemia and autoimmune diseases, treating currently over 1500 cases of non-Hodgkin lymphoma, acute lymphoblastic leukemias, Waldenstrom’s macroglobulinemia, Sjogren’s syndrome, and systemic lupus erythematosus. Because epratuzumab reduces on average only 35% of circulating B cells in patients, and has minimal antibody-dependent cellular cytotoxicity and negligible complement-dependent cytotoxicity when evaluated in vitro, its therapeutic activity may not result completely from B-cell depletion. We reported recently that epratuzumab mediates Fc/FcR-dependent membrane transfer from B cells to effector cells via trogocytosis, resulting in a substantial reduction of multiple BCR modulators, including CD22, CD19, CD21, and CD79b, as well as key cell adhesion molecules, including CD44, CD62L, and β7 integrin, on the surface of B cells in peripheral blood mononuclear cells obtained from normal donors or SLE patients. Rituximab has clinical activity in lupus, but failed to achieve primary endpoints in a Phase III trial. This is the first study of trogocytosis mediated by bispecific antibodies targeting neighboring cell-surface proteins, CD22, CD20, and CD19, as demonstrated by flow cytometry and immunofluorescence microscopy. We show that, compared to epratuzumab, a bispecific hexavalent antibody comprising epratuzumab and veltuzumab (humanized anti-CD20 mAb) exhibits enhanced trogocytosis resulting in major reductions in B-cell surface levels of CD19, CD20, CD21, CD22, CD79b, CD44, CD62L and β7-integrin, and with considerably less immunocompromising B-cell depletion that would result with anti-CD20 mAbs such as veltuzumab or rituximab, given either alone or in combination with epratuzumab. A CD22/CD19 bispecific hexavalent antibody, which exhibited enhanced trogocytosis of some antigens and minimal B-cell depletion, may also be therapeutically useful. The bispecific antibody is a candidate for improved treatment of lupus and other autoimmune diseases, offering advantages over administration of the two parental antibodies in combination.
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op0118 epratuzumab mediates bcr antigen trogocytosis as potential mechanism of action in systemic lupus erythematosus sle
Annals of the Rheumatic Diseases, 2013Co-Authors: David M. Goldenberg, Rosana B. Michel, Edmund A. Rossi, Daniel J. Wallace, Chien-hsing ChangAbstract:Background Epratuzumab, a humanized monoclonal antibody targeting CD22, has demonstrated therapeutic activity in clinical trials of patients with SLE, yet an understanding of its mechanism of action (MOA) is still emerging. Because epratuzumab reduces on average 35% of circulating B cells in patients, its therapeutic efficacy involves MOA beyond B-cell depletion. Modulation of CD22 and other surface molecules that regulate B-cell antigen receptor (BCR) signaling may alter B-cell functions and ultimately mitigate symptoms of the underlying disease. Objectives Using an experimental ex-vivo analysis, we identified trogocytosis as a novel MOA for epratuzumab, which may be important for therapy of SLE and other autoimmune disorders. Clinical specimens of SLE patients were evaluated for evidence of trogocytosis induced by epratuzumab in vivo . Methods PBMCs from either healthy donors or SLE patients were incubated with epratuzumab, and the relative surface levels of CD22, CD19, CD21, and CD79b on B cells were analyzed by flow cytometry (FCM). Trogocytosis was studied with FCM and fluorescence microscopy using B-cell NHL cell lines (Daudi and Raji) mixed with PBMCs, T cells, monocytes, or granulocytes. We further measured the relative levels of CD22, CD19, CD21, and CD79b on B cells from five SLE patients who were receiving epratuzumab, four treatment-naive SLE patients, and two receiving belimumab. Results Epratuzumab promptly induced a marked decrease of surface CD22 (>80%), CD19 (>50%), CD21 (>50%), and CD79b (>30%) on B cells in PBMCs obtained from normal donors or treatment-naive SLE patients. CD27 - B cells were more responsive than CD27 + cells. Within a few hrs, B-cell surface proteins were reduced to a similar level over a broad concentration range (0.01 – 100 µg/mL) of epratuzumab. Although some Fc-independent loss of CD22 is expected from internalization, the concurrent and prominent reduction of CD19, CD21, and CD79b is Fc-dependent and results from trogocytosis of epratuzumab-bound B cells to FcgR-expressing effector cells, including monocytes, NK cells, and granulocytes. Reduced staining of surface antigens on B cells coincided with positive CD19 and CD22 staining of the effector cells. Epratuzumab-induced transfer of membrane components from Daudi cells to monocytes was also evident by fluorescence microscopy. Unlike rituximab, which reduced the B-cell count by 50% in the ex-vivo assay, epratuzumab did not cause significant B-cell depletion. Analysis of SLE patient samples suggests that similar epratuzumab-mediated trogocytosis, as observed ex-vivo , also occurs clinically. As expected, CD22 was significantly ( P 80%) on the B cells of epratuzumab-treated patients. Notably, CD19, CD21 and CD79b were each also significantly ( P Conclusions This study revealed a previously unknown, and potentially important, MOA of epratuzumab. The findings of reduced levels of CD19 are of particular relevance for the efficacy of epratuzumab in SLE, because elevated CD19 has been correlated with susceptibility to SLE in animal models as well as in patients, and down-regulation of CD19 should attenuate activation of B cells by raising the BCR signaling threshold. Disclosure of Interest D. Goldenberg Shareholder of: Immunomedics, Inc., Employee of: Immunomedics, Inc., E. Rossi Employee of: Immunomedics, Inc., R. Michel Employee of: Immunomedics, Inc., D. Wallace: None Declared, C.-H. Chang: None Declared
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op0118 epratuzumab mediates bcr antigen trogocytosis as potential mechanism of action in systemic lupus erythematosus sle
Annals of the Rheumatic Diseases, 2013Co-Authors: David M. Goldenberg, Daniel J. Wallace, Edmund A. Rossi, R. Michel, Chien-hsing ChangAbstract:Background Epratuzumab, a humanized monoclonal antibody targeting CD22, has demonstrated therapeutic activity in clinical trials of patients with SLE, yet an understanding of its mechanism of action (MOA) is still emerging. Because epratuzumab reduces on average 35% of circulating B cells in patients, its therapeutic efficacy involves MOA beyond B-cell depletion. Modulation of CD22 and other surface molecules that regulate B-cell antigen receptor (BCR) signaling may alter B-cell functions and ultimately mitigate symptoms of the underlying disease. Objectives Using an experimental ex-vivo analysis, we identified trogocytosis as a novel MOA for epratuzumab, which may be important for therapy of SLE and other autoimmune disorders. Clinical specimens of SLE patients were evaluated for evidence of trogocytosis induced by epratuzumab in vivo . Methods PBMCs from either healthy donors or SLE patients were incubated with epratuzumab, and the relative surface levels of CD22, CD19, CD21, and CD79b on B cells were analyzed by flow cytometry (FCM). Trogocytosis was studied with FCM and fluorescence microscopy using B-cell NHL cell lines (Daudi and Raji) mixed with PBMCs, T cells, monocytes, or granulocytes. We further measured the relative levels of CD22, CD19, CD21, and CD79b on B cells from five SLE patients who were receiving epratuzumab, four treatment-naive SLE patients, and two receiving belimumab. Results Epratuzumab promptly induced a marked decrease of surface CD22 (>80%), CD19 (>50%), CD21 (>50%), and CD79b (>30%) on B cells in PBMCs obtained from normal donors or treatment-naive SLE patients. CD27- B cells were more responsive than CD27+ cells. Within a few hrs, B-cell surface proteins were reduced to a similar level over a broad concentration range (0.01 – 100 µg/mL) of epratuzumab. Although some Fc-independent loss of CD22 is expected from internalization, the concurrent and prominent reduction of CD19, CD21, and CD79b is Fc-dependent and results from trogocytosis of epratuzumab-bound B cells to FcgR-expressing effector cells, including monocytes, NK cells, and granulocytes. Reduced staining of surface antigens on B cells coincided with positive CD19 and CD22 staining of the effector cells. Epratuzumab-induced transfer of membrane components from Daudi cells to monocytes was also evident by fluorescence microscopy. Unlike rituximab, which reduced the B-cell count by 50% in the ex-vivo assay, epratuzumab did not cause significant B-cell depletion. Analysis of SLE patient samples suggests that similar epratuzumab-mediated trogocytosis, as observed ex-vivo , also occurs clinically. As expected, CD22 was significantly ( P 80%) on the B cells of epratuzumab-treated patients. Notably, CD19, CD21 and CD79b were each also significantly ( P <.02) lower for the epratuzumab group. Conclusions This study revealed a previously unknown, and potentially important, MOA of epratuzumab. The findings of reduced levels of CD19 are of particular relevance for the efficacy of epratuzumab in SLE, because elevated CD19 has been correlated with susceptibility to SLE in animal models as well as in patients, and down-regulation of CD19 should attenuate activation of B cells by raising the BCR signaling threshold. Disclosure of Interest D. Goldenberg Shareholder of: Immunomedics, Inc., Employee of: Immunomedics, Inc., E. Rossi Employee of: Immunomedics, Inc., R. Michel Employee of: Immunomedics, Inc., D. Wallace: None Declared, C.-H. Chang: None Declared
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cd22 targeting epratuzumab down regulates multiple bcr regulators on the surface of normal lupus and malignant b cells
Blood, 2012Co-Authors: Edmund A. Rossi, Rosana B. Michel, Chien-hsing Chang, Daniel J. Wallace, David M. GoldenbergAbstract:Abstract 1357 Background. The humanized anti-CD22 antibody, epratuzumab, has demonstrated therapeutic activity in clinical trials of lymphoma and autoimmune diseases, treating currently over 1000 cases of non-Hodgkin lymphoma (NHL), leukemias, Waldenstrom9s macroglobulinemia, Sjogren9s syndrome, and systemic lupus erythematosus (SLE). Thus, epratuzumab offers a promising option for CD22-targeted immunotherapy, yet its mechanism of action (MOA) remains poorly understood to date. Because epratuzumab reduces on average 35% of circulating B cells in patients, and has minimal antibody–dependent cell-mediated cytotoxicity and negligible complement-dependent cytotoxicity when evaluated in vitro, we reason its therapeutic activity may not result completely from B-cell depletion; instead, ligation of epratuzumab to CD22 could modulate other surface molecules involved in regulating B-cell antigen receptor (BCR) signaling, leading to altered B-cell functions that ultimately mitigate symptoms of the underlying diseases. Here we report for the first time that epratuzumab induces a substantial reduction of CD22 along with CD19, CD21, and CD79b, on the surface of B cells in peripheral blood mononuclear cells (PBMCs) obtained from normal donors or lupus patients, and of cells from three NHL lines (Daudi, Raji, and Ramos) spiked into normal PBMCs. Intriguingly, only CD22, but not others, was appreciably down-regulated by epratuzumab in isolated B cells, implicating additional cell-based factors are required. Methods and Results. PBMCs, from either healthy donors or lupus patients with flares, were incubated with epratuzumab (10 μg/mL) for 2 h or 18 h, and the relative surface expression levels of CD22 and selected BCR regulators, including CD19, CD21, and CD79b, were analyzed by flow cytometry. Treatment of PBMCs from healthy donors with epratuzumab, but not an isotype control mAb, induced a marked down-regulation of CD22 (>80%), CD19 (>50%), CD21 (>50%) and CD79b (>30%) on the surface of B cells, with the stronger effect observed for CD27-negative B cells. The effect of epratuzumab could be observed after 2 h and increased moderately with overnight incubation (18 h). Moreover, substantial reduction of CD22 (>50%), but not others, was achieved with the F(ab9)2 of epratuzumab generated from pepsin digestion. Similar results were observed for B cells in PBMCs of lupus patients. In the absence of PBMCs, treatment of NHL cell lines (Daudi, Raji and Ramos) with epratuzumab resulted in more than 80% reduction of CD22, with little, if any, reduction in CD19, CD21, CD79b or surface IgM observed. Inclusion of a crosslinking second antibody with epratuzumab induced only a minimal ( Conclusions. This study revealed a previously unknown, and potentially important, MOA of epratuzumab. The prominent down-regulation of CD19, CD21, and CD79b by epratuzumab is not only Fc-dependent, but also requires further engagement with certain effector cells present in PBMCs. The findings of reduced levels of CD19 are of particular relevance for the efficacy of epratuzumab in autoimmune diseases, because elevated CD19 has been correlated with susceptibility to SLE in animal models as well as in patients, and down-regulation of CD19 should attenuate activation of B cells by raising the BCR signaling threshold. Disclosures: Rossi:Immunomedics, Inc.: Employment; IBC Pharmaceuticals Inc.: Employment. Michel:Immunomedics, Inc.: Employment. Chang:Immunomedics, Inc.: Employment. Goldenberg:Immunomedics: Employment, Equity Ownership.
Edmund A. Rossi - One of the best experts on this subject based on the ideXlab platform.
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Anti-CD22/CD20 Bispecific Antibody with Enhanced Trogocytosis for Treatment of Lupus
2016Co-Authors: Edmund A. Rossi, Chien-hsing Chang, David M. GoldenbergAbstract:The humanized anti-CD22 antibody, epratuzumab, has demonstrated therapeutic activity in clinical trials of lymphoma, leukemia and autoimmune diseases, treating currently over 1500 cases of non-Hodgkin lymphoma, acute lymphoblastic leukemias, Waldenström’s macroglobulinemia, Sjögren’s syndrome, and systemic lupus erythematosus. Because epratuzumab reduces on average only 35 % of circulating B cells in patients, and has minimal antibody-dependent cellular cytotoxicity and negligible complement-dependent cytotoxicity when evaluated in vitro, its therapeutic activity may not result completely from B-cell depletion. We reported recently that epratuzumab mediates Fc/FcR-dependent membrane transfer from B cells to effector cells via trogocytosis, resulting in a substantial reduction of multiple BCR modulators, including CD22, CD19, CD21, and CD79b, as well as key cell adhesion molecules, including CD44, CD62L, and b7 integrin, on the surface of B cells in peripheral blood mononuclear cells obtained from normal donors or SLE patients. Rituximab has clinical activity in lupus, but failed to achieve primary endpoints in a Phase III trial. This is the first study of trogocytosis mediated by bispecific antibodies targeting neighboring cell-surface proteins, CD22, CD20, and CD19, as demonstrated by flow cytometry and immunofluorescence microscopy. We show that, compared to epratuzumab, a bispecific hexavalent antibody comprising epratuzumab and veltuzumab (humanized anti-CD20 mAb) exhibits enhanced trogocytosis resulting in major reductions in B-cell surface levels of CD19, CD20, CD21, CD22, CD79b, CD44, CD62L and b7-integrin, and wit
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anti cd22 cd20 bispecific antibody with enhanced trogocytosis for treatment of lupus
PLOS ONE, 2014Co-Authors: Edmund A. Rossi, Chien-hsing Chang, David M. GoldenbergAbstract:The humanized anti-CD22 antibody, epratuzumab, has demonstrated therapeutic activity in clinical trials of lymphoma, leukemia and autoimmune diseases, treating currently over 1500 cases of non-Hodgkin lymphoma, acute lymphoblastic leukemias, Waldenstrom’s macroglobulinemia, Sjogren’s syndrome, and systemic lupus erythematosus. Because epratuzumab reduces on average only 35% of circulating B cells in patients, and has minimal antibody-dependent cellular cytotoxicity and negligible complement-dependent cytotoxicity when evaluated in vitro, its therapeutic activity may not result completely from B-cell depletion. We reported recently that epratuzumab mediates Fc/FcR-dependent membrane transfer from B cells to effector cells via trogocytosis, resulting in a substantial reduction of multiple BCR modulators, including CD22, CD19, CD21, and CD79b, as well as key cell adhesion molecules, including CD44, CD62L, and β7 integrin, on the surface of B cells in peripheral blood mononuclear cells obtained from normal donors or SLE patients. Rituximab has clinical activity in lupus, but failed to achieve primary endpoints in a Phase III trial. This is the first study of trogocytosis mediated by bispecific antibodies targeting neighboring cell-surface proteins, CD22, CD20, and CD19, as demonstrated by flow cytometry and immunofluorescence microscopy. We show that, compared to epratuzumab, a bispecific hexavalent antibody comprising epratuzumab and veltuzumab (humanized anti-CD20 mAb) exhibits enhanced trogocytosis resulting in major reductions in B-cell surface levels of CD19, CD20, CD21, CD22, CD79b, CD44, CD62L and β7-integrin, and with considerably less immunocompromising B-cell depletion that would result with anti-CD20 mAbs such as veltuzumab or rituximab, given either alone or in combination with epratuzumab. A CD22/CD19 bispecific hexavalent antibody, which exhibited enhanced trogocytosis of some antigens and minimal B-cell depletion, may also be therapeutically useful. The bispecific antibody is a candidate for improved treatment of lupus and other autoimmune diseases, offering advantages over administration of the two parental antibodies in combination.
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op0118 epratuzumab mediates bcr antigen trogocytosis as potential mechanism of action in systemic lupus erythematosus sle
Annals of the Rheumatic Diseases, 2013Co-Authors: David M. Goldenberg, Rosana B. Michel, Edmund A. Rossi, Daniel J. Wallace, Chien-hsing ChangAbstract:Background Epratuzumab, a humanized monoclonal antibody targeting CD22, has demonstrated therapeutic activity in clinical trials of patients with SLE, yet an understanding of its mechanism of action (MOA) is still emerging. Because epratuzumab reduces on average 35% of circulating B cells in patients, its therapeutic efficacy involves MOA beyond B-cell depletion. Modulation of CD22 and other surface molecules that regulate B-cell antigen receptor (BCR) signaling may alter B-cell functions and ultimately mitigate symptoms of the underlying disease. Objectives Using an experimental ex-vivo analysis, we identified trogocytosis as a novel MOA for epratuzumab, which may be important for therapy of SLE and other autoimmune disorders. Clinical specimens of SLE patients were evaluated for evidence of trogocytosis induced by epratuzumab in vivo . Methods PBMCs from either healthy donors or SLE patients were incubated with epratuzumab, and the relative surface levels of CD22, CD19, CD21, and CD79b on B cells were analyzed by flow cytometry (FCM). Trogocytosis was studied with FCM and fluorescence microscopy using B-cell NHL cell lines (Daudi and Raji) mixed with PBMCs, T cells, monocytes, or granulocytes. We further measured the relative levels of CD22, CD19, CD21, and CD79b on B cells from five SLE patients who were receiving epratuzumab, four treatment-naive SLE patients, and two receiving belimumab. Results Epratuzumab promptly induced a marked decrease of surface CD22 (>80%), CD19 (>50%), CD21 (>50%), and CD79b (>30%) on B cells in PBMCs obtained from normal donors or treatment-naive SLE patients. CD27 - B cells were more responsive than CD27 + cells. Within a few hrs, B-cell surface proteins were reduced to a similar level over a broad concentration range (0.01 – 100 µg/mL) of epratuzumab. Although some Fc-independent loss of CD22 is expected from internalization, the concurrent and prominent reduction of CD19, CD21, and CD79b is Fc-dependent and results from trogocytosis of epratuzumab-bound B cells to FcgR-expressing effector cells, including monocytes, NK cells, and granulocytes. Reduced staining of surface antigens on B cells coincided with positive CD19 and CD22 staining of the effector cells. Epratuzumab-induced transfer of membrane components from Daudi cells to monocytes was also evident by fluorescence microscopy. Unlike rituximab, which reduced the B-cell count by 50% in the ex-vivo assay, epratuzumab did not cause significant B-cell depletion. Analysis of SLE patient samples suggests that similar epratuzumab-mediated trogocytosis, as observed ex-vivo , also occurs clinically. As expected, CD22 was significantly ( P 80%) on the B cells of epratuzumab-treated patients. Notably, CD19, CD21 and CD79b were each also significantly ( P Conclusions This study revealed a previously unknown, and potentially important, MOA of epratuzumab. The findings of reduced levels of CD19 are of particular relevance for the efficacy of epratuzumab in SLE, because elevated CD19 has been correlated with susceptibility to SLE in animal models as well as in patients, and down-regulation of CD19 should attenuate activation of B cells by raising the BCR signaling threshold. Disclosure of Interest D. Goldenberg Shareholder of: Immunomedics, Inc., Employee of: Immunomedics, Inc., E. Rossi Employee of: Immunomedics, Inc., R. Michel Employee of: Immunomedics, Inc., D. Wallace: None Declared, C.-H. Chang: None Declared
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op0118 epratuzumab mediates bcr antigen trogocytosis as potential mechanism of action in systemic lupus erythematosus sle
Annals of the Rheumatic Diseases, 2013Co-Authors: David M. Goldenberg, Daniel J. Wallace, Edmund A. Rossi, R. Michel, Chien-hsing ChangAbstract:Background Epratuzumab, a humanized monoclonal antibody targeting CD22, has demonstrated therapeutic activity in clinical trials of patients with SLE, yet an understanding of its mechanism of action (MOA) is still emerging. Because epratuzumab reduces on average 35% of circulating B cells in patients, its therapeutic efficacy involves MOA beyond B-cell depletion. Modulation of CD22 and other surface molecules that regulate B-cell antigen receptor (BCR) signaling may alter B-cell functions and ultimately mitigate symptoms of the underlying disease. Objectives Using an experimental ex-vivo analysis, we identified trogocytosis as a novel MOA for epratuzumab, which may be important for therapy of SLE and other autoimmune disorders. Clinical specimens of SLE patients were evaluated for evidence of trogocytosis induced by epratuzumab in vivo . Methods PBMCs from either healthy donors or SLE patients were incubated with epratuzumab, and the relative surface levels of CD22, CD19, CD21, and CD79b on B cells were analyzed by flow cytometry (FCM). Trogocytosis was studied with FCM and fluorescence microscopy using B-cell NHL cell lines (Daudi and Raji) mixed with PBMCs, T cells, monocytes, or granulocytes. We further measured the relative levels of CD22, CD19, CD21, and CD79b on B cells from five SLE patients who were receiving epratuzumab, four treatment-naive SLE patients, and two receiving belimumab. Results Epratuzumab promptly induced a marked decrease of surface CD22 (>80%), CD19 (>50%), CD21 (>50%), and CD79b (>30%) on B cells in PBMCs obtained from normal donors or treatment-naive SLE patients. CD27- B cells were more responsive than CD27+ cells. Within a few hrs, B-cell surface proteins were reduced to a similar level over a broad concentration range (0.01 – 100 µg/mL) of epratuzumab. Although some Fc-independent loss of CD22 is expected from internalization, the concurrent and prominent reduction of CD19, CD21, and CD79b is Fc-dependent and results from trogocytosis of epratuzumab-bound B cells to FcgR-expressing effector cells, including monocytes, NK cells, and granulocytes. Reduced staining of surface antigens on B cells coincided with positive CD19 and CD22 staining of the effector cells. Epratuzumab-induced transfer of membrane components from Daudi cells to monocytes was also evident by fluorescence microscopy. Unlike rituximab, which reduced the B-cell count by 50% in the ex-vivo assay, epratuzumab did not cause significant B-cell depletion. Analysis of SLE patient samples suggests that similar epratuzumab-mediated trogocytosis, as observed ex-vivo , also occurs clinically. As expected, CD22 was significantly ( P 80%) on the B cells of epratuzumab-treated patients. Notably, CD19, CD21 and CD79b were each also significantly ( P <.02) lower for the epratuzumab group. Conclusions This study revealed a previously unknown, and potentially important, MOA of epratuzumab. The findings of reduced levels of CD19 are of particular relevance for the efficacy of epratuzumab in SLE, because elevated CD19 has been correlated with susceptibility to SLE in animal models as well as in patients, and down-regulation of CD19 should attenuate activation of B cells by raising the BCR signaling threshold. Disclosure of Interest D. Goldenberg Shareholder of: Immunomedics, Inc., Employee of: Immunomedics, Inc., E. Rossi Employee of: Immunomedics, Inc., R. Michel Employee of: Immunomedics, Inc., D. Wallace: None Declared, C.-H. Chang: None Declared
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cd22 targeting epratuzumab down regulates multiple bcr regulators on the surface of normal lupus and malignant b cells
Blood, 2012Co-Authors: Edmund A. Rossi, Rosana B. Michel, Chien-hsing Chang, Daniel J. Wallace, David M. GoldenbergAbstract:Abstract 1357 Background. The humanized anti-CD22 antibody, epratuzumab, has demonstrated therapeutic activity in clinical trials of lymphoma and autoimmune diseases, treating currently over 1000 cases of non-Hodgkin lymphoma (NHL), leukemias, Waldenstrom9s macroglobulinemia, Sjogren9s syndrome, and systemic lupus erythematosus (SLE). Thus, epratuzumab offers a promising option for CD22-targeted immunotherapy, yet its mechanism of action (MOA) remains poorly understood to date. Because epratuzumab reduces on average 35% of circulating B cells in patients, and has minimal antibody–dependent cell-mediated cytotoxicity and negligible complement-dependent cytotoxicity when evaluated in vitro, we reason its therapeutic activity may not result completely from B-cell depletion; instead, ligation of epratuzumab to CD22 could modulate other surface molecules involved in regulating B-cell antigen receptor (BCR) signaling, leading to altered B-cell functions that ultimately mitigate symptoms of the underlying diseases. Here we report for the first time that epratuzumab induces a substantial reduction of CD22 along with CD19, CD21, and CD79b, on the surface of B cells in peripheral blood mononuclear cells (PBMCs) obtained from normal donors or lupus patients, and of cells from three NHL lines (Daudi, Raji, and Ramos) spiked into normal PBMCs. Intriguingly, only CD22, but not others, was appreciably down-regulated by epratuzumab in isolated B cells, implicating additional cell-based factors are required. Methods and Results. PBMCs, from either healthy donors or lupus patients with flares, were incubated with epratuzumab (10 μg/mL) for 2 h or 18 h, and the relative surface expression levels of CD22 and selected BCR regulators, including CD19, CD21, and CD79b, were analyzed by flow cytometry. Treatment of PBMCs from healthy donors with epratuzumab, but not an isotype control mAb, induced a marked down-regulation of CD22 (>80%), CD19 (>50%), CD21 (>50%) and CD79b (>30%) on the surface of B cells, with the stronger effect observed for CD27-negative B cells. The effect of epratuzumab could be observed after 2 h and increased moderately with overnight incubation (18 h). Moreover, substantial reduction of CD22 (>50%), but not others, was achieved with the F(ab9)2 of epratuzumab generated from pepsin digestion. Similar results were observed for B cells in PBMCs of lupus patients. In the absence of PBMCs, treatment of NHL cell lines (Daudi, Raji and Ramos) with epratuzumab resulted in more than 80% reduction of CD22, with little, if any, reduction in CD19, CD21, CD79b or surface IgM observed. Inclusion of a crosslinking second antibody with epratuzumab induced only a minimal ( Conclusions. This study revealed a previously unknown, and potentially important, MOA of epratuzumab. The prominent down-regulation of CD19, CD21, and CD79b by epratuzumab is not only Fc-dependent, but also requires further engagement with certain effector cells present in PBMCs. The findings of reduced levels of CD19 are of particular relevance for the efficacy of epratuzumab in autoimmune diseases, because elevated CD19 has been correlated with susceptibility to SLE in animal models as well as in patients, and down-regulation of CD19 should attenuate activation of B cells by raising the BCR signaling threshold. Disclosures: Rossi:Immunomedics, Inc.: Employment; IBC Pharmaceuticals Inc.: Employment. Michel:Immunomedics, Inc.: Employment. Chang:Immunomedics, Inc.: Employment. Goldenberg:Immunomedics: Employment, Equity Ownership.
Thomas L Rothstein - One of the best experts on this subject based on the ideXlab platform.
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distinctions among circulating antibody secreting cell populations including b 1 cells in human adult peripheral blood
Journal of Immunology, 2016Co-Authors: Tam D Quach, Nely Rodriguezzhurbenko, Thomas J Hopkins, Xiaoti Guo, Ana Maria Hernandez, Thomas L RothsteinAbstract:Human Ab-secreting cell (ASC) populations in circulation are not well studied. In addition to B-1 (CD20(+)CD27(+)CD38(lo/int)CD43(+)) cell and conventional plasmablast (PB) (CD20-CD27(hi)CD38(hi)) cell populations, in this study, we identified a novel B cell population termed 20(+)38(hi) B cells (CD20(+)CD27(hi)CD38(hi)) that spontaneously secretes Ab. At steady-state, 20(+)38(hi) B cells are distinct from PBs on the basis of CD20 expression, amount of Ab production, frequency of mutation, and diversity of BCR repertoire. However, cytokine treatment of 20(+)38(hi) B cells induces loss of CD20 and acquisition of CD138, suggesting that 20(+)38(hi) B cells are precursors to PBs or pre-PBs. We then evaluated similarities and differences among CD20(+)CD27(+)CD38(lo/int)CD43(+) B-1 cells, CD20(+)CD27(hi)CD38(hi) 20(+)38(hi) B cells, CD20(-)CD27(hi)CD38(hi) PBs, and CD20(+)CD27(+)CD38(lo/int)CD43(-) memory B cells. We found that B-1 cells differ from 20(+)38(hi) B cells and PBs in a number of ways, including Ag expression, morphological appearance, transcriptional profiling, Ab skewing, Ab repertoire, and secretory response to stimulation. In terms of gene expression, B-1 cells align more closely with memory B cells than with 20(+)38(hi) B cells or PBs, but differ in that memory B cells do not express Ab secretion-related genes. We found that B-1 cell Abs use Vh4-34, which is often associated with autoreactivity, 3- to 6-fold more often than other B cell populations. Along with selective production of IgM anti-phosphoryl choline, these data suggest that human B-1 cells might be preferentially selected for autoreactivity/natural specificity. In summary, our results indicate that human healthy adult peripheral blood at steady-state consists of three distinct ASC populations.
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human b1 cells in umbilical cord and adult peripheral blood express the novel phenotype cd20 CD27 cd43 cd70
Journal of Experimental Medicine, 2011Co-Authors: Daniel O Griffin, Nichol E Holodick, Thomas L RothsteinAbstract:B1 cells differ in many ways from conventional B cells, most prominently in the production of natural immunoglobulin, which is vitally important for protection against pathogens. B1 cells have also been implicated in the pathogenesis of autoimmune dyscrasias and malignant diseases. It has been impossible to accurately study B1 cells during health and illness because the nature of human B1 cells has not been successfully defined. This has produced controversy regarding the existence of human B1 cells. Here, we determined the phenotype of human B1 cells by testing sort-purified B cell fractions for three fundamental B1 cell functions based on mouse studies: spontaneous IgM secretion, efficient T cell stimulation, and tonic intracellular signaling. We found that a small population of CD20+CD27+CD43+ cells present in both umbilical cord and adult peripheral blood fulfilled these criteria and expressed a skewed B cell receptor repertoire. These B cells express little or no surface CD69 and CD70, both of which are markedly up-regulated after activation of CD20+CD27−CD43− (naive) and CD20+CD27+CD43− (memory) B cells. This work identifies human B1 cells as CD20+CD27+CD43+CD70−. We determined that the proportion of B1 cells declines with age, which may contribute to disease susceptibility. Identification of human B1 cells provides a foundation for future studies on the nature and role of these cells in human disease.
Jannie Borst - One of the best experts on this subject based on the ideXlab platform.
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CD27 promotes survival of activated t cells and complements cd28 in generation and establishment of the effector t cell pool
Journal of Experimental Medicine, 2003Co-Authors: Jenny Hendriks, Yanling Xiao, Jannie BorstAbstract:CD27, like CD28, acts in concert with the T cell receptor to support T cell expansion. Using CD27−/− mice, we have shown earlier that CD27 determines the magnitude of primary and memory T cell responses to influenza virus. Here, we have examined the relative contributions of CD27 and CD28 to generation of the virus-specific effector T cell pool and its establishment at the site of infection (the lung), using CD27−/−, CD28−/−, and CD27/CD28−/− mice. We find that primary and memory CD8+ T cell responses to influenza virus are dependent on the collective contribution of both receptors. In the primary response, CD27 and CD28 impact to a similar extent on expansion of virus-specific T cells in draining lymph nodes. CD27 is the principle determinant for accumulation of virus-specific T cells in the lung because it can sustain this response in CD28−/− mice. Unlike CD28, CD27 does not affect cell cycle activity, but promotes survival of activated T cells throughout successive rounds of division at the site of priming and may do so at the site of infection as well. CD27 was found to rescue CD28−/− T cells from death at the onset of division, explaining its capacity to support a T cell response in absence of CD28.
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CD27 is required for generation and long term maintenance of t cell immunity
Nature Immunology, 2000Co-Authors: Jenny Hendriks, Loes A Gravestein, Kiki Tesselaar, Rene A W Van Lier, Ton N M Schumacher, Jannie BorstAbstract:The Traf-linked tumor necrosis factor receptor family member CD27 is known as a T cell costimulatory molecule. We generated CD27-/- mice and found that CD27 makes essential contributions to mature CD4+ and CD8+ T cell function: CD27 supported antigen-specific expansion (but not effector cell maturation) of naive T cells, independent of the cell cycle-promoting activities of CD28 and interleukin 2. Primary CD4+ and CD8+ T cell responses to influenza virus were impaired in CD27-/- mice. Effects of deleting the gene encoding CD27 were most profound on T cell memory, reflected by delayed response kinetics and reduction of CD8+ virus-specific T cell numbers to the level seen in the primary response. This demonstrates the requirement for a costimulatory receptor in the generation of T cell memory.