The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform

E Berti - One of the best experts on this subject based on the ideXlab platform.

  • primary cutaneous cd8 positive epidermotropic cytotoxic t cell lymphomas a distinct clinicopathological entity with an aggressive clinical behavior
    American Journal of Pathology, 1999
    Co-Authors: E Berti, Dario Tomasini, Maarten H Vermeer, Chris J L M Meijer, E Alessi, Rein Willemze
    Abstract:

    Cutaneous T cell lymphomas (CTCL) generally have the phenotype of CD3+, CD4+, CD45RO+ memory T cells. CTCL expressing a CD8+ T cell phenotype are extremely rare and ill-defined. To elucidate whether these CD8+ CTCL represent a distinct disease entity, the clinical, histological, and immunophenotypical features of 17 CD8+ CTCL were reviewed. None of the 17 cases expressed markers characteristic of natural killer cells or γ/δ T cells. Nine of 17 cases showed the characteristic clinical and histological features as well as clinical behavior of well defined types of CTCL, such as mycosis fungoides (2 cases), pagetoid reticulosis (2 cases), lymphomatoid papulosis (2 cases), and CD30+ large T cell lymphoma (2 cases), all of which usually express a CD4+ T cell phenotype, and 1 case of subcutaneous panniculitis-like T cell lymphoma. The other 8 cases formed a homogeneous group showing a distinctive set of clinicopathological and immunophenotypical features, not consistent with that of other well defined types of CTCL. Clinical characteristics included presentation with generalized patches, plaques, papulonodules, and tumors mimicking disseminated pagetoid reticulosis; metastatic spread to unusual sites, such as the lung, testis, central nervous system, and oral cavity, but not to the lymph nodes; and an aggressive course (median survival, 32 months). Histologically, these lymphomas were characterized by band-like infiltrates consisting of pleomorphic T cells or immunoblasts, showing a diffuse infiltration of an acanthotic epidermis with variable degrees of spongiosis, intraepidermal blistering, and necrosis. The neoplastic cells showed a high Ki-67 proliferation index and expression of CD3, CD8, CD7, CD45RA, βF1, and TIA-1 markers, whereas CD2 and CD5 were frequently lost. Expression of TIA-1 pointed out that these lymphomas are derived from a cytotoxic T cell subset. The results of this and other studies reviewed herein suggest that these strongly epidermotropic primary cutaneous CD8+ cytotoxic T cell lymphomas represent a distinct type of CTCL with an aggressive clinical behavior.

  • primary cutaneous cd8 positive epidermotropic cytotoxic t cell lymphomas a distinct clinicopathological entity with an aggressive clinical behavior
    American Journal of Pathology, 1999
    Co-Authors: E Berti, Dario Tomasini, Maarten H Vermeer, Chris J L M Meijer, E Alessi, Rein Willemze
    Abstract:

    Cutaneous T cell lymphomas (CTCL) generally have the phenotype of CD3+, CD4+, CD45RO+ memory T cells. CTCL expressing a CD8+ T cell phenotype are extremely rare and ill-defined. To elucidate whether these CD8+ CTCL represent a distinct disease entity, the clinical, histological, and immunophenotypical features of 17 CD8+ CTCL were reviewed. None of the 17 cases expressed markers characteristic of natural killer cells or γ/δ T cells. Nine of 17 cases showed the characteristic clinical and histological features as well as clinical behavior of well defined types of CTCL, such as mycosis fungoides (2 cases), pagetoid reticulosis (2 cases), lymphomatoid papulosis (2 cases), and CD30+ large T cell lymphoma (2 cases), all of which usually express a CD4+ T cell phenotype, and 1 case of subcutaneous panniculitis-like T cell lymphoma. The other 8 cases formed a homogeneous group showing a distinctive set of clinicopathological and immunophenotypical features, not consistent with that of other well defined types of CTCL. Clinical characteristics included presentation with generalized patches, plaques, papulonodules, and tumors mimicking disseminated pagetoid reticulosis; metastatic spread to unusual sites, such as the lung, testis, central nervous system, and oral cavity, but not to the lymph nodes; and an aggressive course (median survival, 32 months). Histologically, these lymphomas were characterized by band-like infiltrates consisting of pleomorphic T cells or immunoblasts, showing a diffuse infiltration of an acanthotic epidermis with variable degrees of spongiosis, intraepidermal blistering, and necrosis. The neoplastic cells showed a high Ki-67 proliferation index and expression of CD3, CD8, CD7, CD45RA, βF1, and TIA-1 markers, whereas CD2 and CD5 were frequently lost. Expression of TIA-1 pointed out that these lymphomas are derived from a cytotoxic T cell subset. The results of this and other studies reviewed herein suggest that these strongly epidermotropic primary cutaneous CD8+ cytotoxic T cell lymphomas represent a distinct type of CTCL with an aggressive clinical behavior.

  • primary cutaneous γ δ t cell lymphoma presenting as disseminated pagetoid reticulosis
    Journal of Investigative Dermatology, 1991
    Co-Authors: E Berti, E Alessi, A Cerri, S Cavicchini, Domenico Delia, D Soligo, R Caputo
    Abstract:

    Abstract The first case of primary γ/δ cutaneous T-cell lymphoma (CTCL) with a fatal outcome is reported. The patient had the clinical and histopathologic features of disseminated page told reticulosis, a rare form of CTCL characterized by a strong epidermotropic lymphoid infiltrate. Extensive immuno-cytochemical studies showed that the neoplastic cells were almost exclusively localized in the epidermis, expressed the γ/δ variant of the T-cell receptor (CD3 + , TCR-δ-1 + ) and were CD5 + , CD7 + , CD27 + , CD29 + , CD43 + , CD44 + , CD45 + , CD45RA + , CD54 + , CD69 + , but βF1 − , Tiγa − , BB3 − , A13 − , CD2 − , CD4 − , CD8 − , CD11a − , CD49d − , CD25 − , CD30 − , and HLA-DR − . A comparison of our results with those of the literature, which have not included γ/δ T-cell receptor analysis, suggests that some reported cases of pagetoid reticulosis may have phenotypes similar to our case. Electron microscopy studies demonstrated that the γ/δ T lymphocytes were villous, containing dense and multivesicular bodies, and formed close contacts with the surrounding keratinocytes, suggesting that these cells should have a role in the skin-associated lymphoid tissue. The proliferating cells in our case might represent the neoplastic counterpart of the recently reported CD2 − subset of normal human peripheral blood γ/δ T lymphocytes.

Rein Willemze - One of the best experts on this subject based on the ideXlab platform.

  • primary cutaneous cd8 positive epidermotropic cytotoxic t cell lymphomas a distinct clinicopathological entity with an aggressive clinical behavior
    American Journal of Pathology, 1999
    Co-Authors: E Berti, Dario Tomasini, Maarten H Vermeer, Chris J L M Meijer, E Alessi, Rein Willemze
    Abstract:

    Cutaneous T cell lymphomas (CTCL) generally have the phenotype of CD3+, CD4+, CD45RO+ memory T cells. CTCL expressing a CD8+ T cell phenotype are extremely rare and ill-defined. To elucidate whether these CD8+ CTCL represent a distinct disease entity, the clinical, histological, and immunophenotypical features of 17 CD8+ CTCL were reviewed. None of the 17 cases expressed markers characteristic of natural killer cells or γ/δ T cells. Nine of 17 cases showed the characteristic clinical and histological features as well as clinical behavior of well defined types of CTCL, such as mycosis fungoides (2 cases), pagetoid reticulosis (2 cases), lymphomatoid papulosis (2 cases), and CD30+ large T cell lymphoma (2 cases), all of which usually express a CD4+ T cell phenotype, and 1 case of subcutaneous panniculitis-like T cell lymphoma. The other 8 cases formed a homogeneous group showing a distinctive set of clinicopathological and immunophenotypical features, not consistent with that of other well defined types of CTCL. Clinical characteristics included presentation with generalized patches, plaques, papulonodules, and tumors mimicking disseminated pagetoid reticulosis; metastatic spread to unusual sites, such as the lung, testis, central nervous system, and oral cavity, but not to the lymph nodes; and an aggressive course (median survival, 32 months). Histologically, these lymphomas were characterized by band-like infiltrates consisting of pleomorphic T cells or immunoblasts, showing a diffuse infiltration of an acanthotic epidermis with variable degrees of spongiosis, intraepidermal blistering, and necrosis. The neoplastic cells showed a high Ki-67 proliferation index and expression of CD3, CD8, CD7, CD45RA, βF1, and TIA-1 markers, whereas CD2 and CD5 were frequently lost. Expression of TIA-1 pointed out that these lymphomas are derived from a cytotoxic T cell subset. The results of this and other studies reviewed herein suggest that these strongly epidermotropic primary cutaneous CD8+ cytotoxic T cell lymphomas represent a distinct type of CTCL with an aggressive clinical behavior.

  • primary cutaneous cd8 positive epidermotropic cytotoxic t cell lymphomas a distinct clinicopathological entity with an aggressive clinical behavior
    American Journal of Pathology, 1999
    Co-Authors: E Berti, Dario Tomasini, Maarten H Vermeer, Chris J L M Meijer, E Alessi, Rein Willemze
    Abstract:

    Cutaneous T cell lymphomas (CTCL) generally have the phenotype of CD3+, CD4+, CD45RO+ memory T cells. CTCL expressing a CD8+ T cell phenotype are extremely rare and ill-defined. To elucidate whether these CD8+ CTCL represent a distinct disease entity, the clinical, histological, and immunophenotypical features of 17 CD8+ CTCL were reviewed. None of the 17 cases expressed markers characteristic of natural killer cells or γ/δ T cells. Nine of 17 cases showed the characteristic clinical and histological features as well as clinical behavior of well defined types of CTCL, such as mycosis fungoides (2 cases), pagetoid reticulosis (2 cases), lymphomatoid papulosis (2 cases), and CD30+ large T cell lymphoma (2 cases), all of which usually express a CD4+ T cell phenotype, and 1 case of subcutaneous panniculitis-like T cell lymphoma. The other 8 cases formed a homogeneous group showing a distinctive set of clinicopathological and immunophenotypical features, not consistent with that of other well defined types of CTCL. Clinical characteristics included presentation with generalized patches, plaques, papulonodules, and tumors mimicking disseminated pagetoid reticulosis; metastatic spread to unusual sites, such as the lung, testis, central nervous system, and oral cavity, but not to the lymph nodes; and an aggressive course (median survival, 32 months). Histologically, these lymphomas were characterized by band-like infiltrates consisting of pleomorphic T cells or immunoblasts, showing a diffuse infiltration of an acanthotic epidermis with variable degrees of spongiosis, intraepidermal blistering, and necrosis. The neoplastic cells showed a high Ki-67 proliferation index and expression of CD3, CD8, CD7, CD45RA, βF1, and TIA-1 markers, whereas CD2 and CD5 were frequently lost. Expression of TIA-1 pointed out that these lymphomas are derived from a cytotoxic T cell subset. The results of this and other studies reviewed herein suggest that these strongly epidermotropic primary cutaneous CD8+ cytotoxic T cell lymphomas represent a distinct type of CTCL with an aggressive clinical behavior.

E Alessi - One of the best experts on this subject based on the ideXlab platform.

  • primary cutaneous cd8 positive epidermotropic cytotoxic t cell lymphomas a distinct clinicopathological entity with an aggressive clinical behavior
    American Journal of Pathology, 1999
    Co-Authors: E Berti, Dario Tomasini, Maarten H Vermeer, Chris J L M Meijer, E Alessi, Rein Willemze
    Abstract:

    Cutaneous T cell lymphomas (CTCL) generally have the phenotype of CD3+, CD4+, CD45RO+ memory T cells. CTCL expressing a CD8+ T cell phenotype are extremely rare and ill-defined. To elucidate whether these CD8+ CTCL represent a distinct disease entity, the clinical, histological, and immunophenotypical features of 17 CD8+ CTCL were reviewed. None of the 17 cases expressed markers characteristic of natural killer cells or γ/δ T cells. Nine of 17 cases showed the characteristic clinical and histological features as well as clinical behavior of well defined types of CTCL, such as mycosis fungoides (2 cases), pagetoid reticulosis (2 cases), lymphomatoid papulosis (2 cases), and CD30+ large T cell lymphoma (2 cases), all of which usually express a CD4+ T cell phenotype, and 1 case of subcutaneous panniculitis-like T cell lymphoma. The other 8 cases formed a homogeneous group showing a distinctive set of clinicopathological and immunophenotypical features, not consistent with that of other well defined types of CTCL. Clinical characteristics included presentation with generalized patches, plaques, papulonodules, and tumors mimicking disseminated pagetoid reticulosis; metastatic spread to unusual sites, such as the lung, testis, central nervous system, and oral cavity, but not to the lymph nodes; and an aggressive course (median survival, 32 months). Histologically, these lymphomas were characterized by band-like infiltrates consisting of pleomorphic T cells or immunoblasts, showing a diffuse infiltration of an acanthotic epidermis with variable degrees of spongiosis, intraepidermal blistering, and necrosis. The neoplastic cells showed a high Ki-67 proliferation index and expression of CD3, CD8, CD7, CD45RA, βF1, and TIA-1 markers, whereas CD2 and CD5 were frequently lost. Expression of TIA-1 pointed out that these lymphomas are derived from a cytotoxic T cell subset. The results of this and other studies reviewed herein suggest that these strongly epidermotropic primary cutaneous CD8+ cytotoxic T cell lymphomas represent a distinct type of CTCL with an aggressive clinical behavior.

  • primary cutaneous cd8 positive epidermotropic cytotoxic t cell lymphomas a distinct clinicopathological entity with an aggressive clinical behavior
    American Journal of Pathology, 1999
    Co-Authors: E Berti, Dario Tomasini, Maarten H Vermeer, Chris J L M Meijer, E Alessi, Rein Willemze
    Abstract:

    Cutaneous T cell lymphomas (CTCL) generally have the phenotype of CD3+, CD4+, CD45RO+ memory T cells. CTCL expressing a CD8+ T cell phenotype are extremely rare and ill-defined. To elucidate whether these CD8+ CTCL represent a distinct disease entity, the clinical, histological, and immunophenotypical features of 17 CD8+ CTCL were reviewed. None of the 17 cases expressed markers characteristic of natural killer cells or γ/δ T cells. Nine of 17 cases showed the characteristic clinical and histological features as well as clinical behavior of well defined types of CTCL, such as mycosis fungoides (2 cases), pagetoid reticulosis (2 cases), lymphomatoid papulosis (2 cases), and CD30+ large T cell lymphoma (2 cases), all of which usually express a CD4+ T cell phenotype, and 1 case of subcutaneous panniculitis-like T cell lymphoma. The other 8 cases formed a homogeneous group showing a distinctive set of clinicopathological and immunophenotypical features, not consistent with that of other well defined types of CTCL. Clinical characteristics included presentation with generalized patches, plaques, papulonodules, and tumors mimicking disseminated pagetoid reticulosis; metastatic spread to unusual sites, such as the lung, testis, central nervous system, and oral cavity, but not to the lymph nodes; and an aggressive course (median survival, 32 months). Histologically, these lymphomas were characterized by band-like infiltrates consisting of pleomorphic T cells or immunoblasts, showing a diffuse infiltration of an acanthotic epidermis with variable degrees of spongiosis, intraepidermal blistering, and necrosis. The neoplastic cells showed a high Ki-67 proliferation index and expression of CD3, CD8, CD7, CD45RA, βF1, and TIA-1 markers, whereas CD2 and CD5 were frequently lost. Expression of TIA-1 pointed out that these lymphomas are derived from a cytotoxic T cell subset. The results of this and other studies reviewed herein suggest that these strongly epidermotropic primary cutaneous CD8+ cytotoxic T cell lymphomas represent a distinct type of CTCL with an aggressive clinical behavior.

  • primary cutaneous γ δ t cell lymphoma presenting as disseminated pagetoid reticulosis
    Journal of Investigative Dermatology, 1991
    Co-Authors: E Berti, E Alessi, A Cerri, S Cavicchini, Domenico Delia, D Soligo, R Caputo
    Abstract:

    Abstract The first case of primary γ/δ cutaneous T-cell lymphoma (CTCL) with a fatal outcome is reported. The patient had the clinical and histopathologic features of disseminated page told reticulosis, a rare form of CTCL characterized by a strong epidermotropic lymphoid infiltrate. Extensive immuno-cytochemical studies showed that the neoplastic cells were almost exclusively localized in the epidermis, expressed the γ/δ variant of the T-cell receptor (CD3 + , TCR-δ-1 + ) and were CD5 + , CD7 + , CD27 + , CD29 + , CD43 + , CD44 + , CD45 + , CD45RA + , CD54 + , CD69 + , but βF1 − , Tiγa − , BB3 − , A13 − , CD2 − , CD4 − , CD8 − , CD11a − , CD49d − , CD25 − , CD30 − , and HLA-DR − . A comparison of our results with those of the literature, which have not included γ/δ T-cell receptor analysis, suggests that some reported cases of pagetoid reticulosis may have phenotypes similar to our case. Electron microscopy studies demonstrated that the γ/δ T lymphocytes were villous, containing dense and multivesicular bodies, and formed close contacts with the surrounding keratinocytes, suggesting that these cells should have a role in the skin-associated lymphoid tissue. The proliferating cells in our case might represent the neoplastic counterpart of the recently reported CD2 − subset of normal human peripheral blood γ/δ T lymphocytes.

Gerd Walz - One of the best experts on this subject based on the ideXlab platform.

  • the molecular basis for the synergism between the cd3 alpha beta t cell receptor and the cd2 antigen derived signals in promoting t cell proliferation
    Transplantation, 1991
    Co-Authors: P. K. Sehajpal, Bernd Zanker, V.k. Murthi, A. Subramaniam, V. K. Sharma, D. Estin, E. Y. Skonik, Kenneth J. Wieder, Gerd Walz, M Fotino
    Abstract:

    Northern blot analysis and a highly sensitive methodology for mRNA phenotyping, polymerase chain reaction (PCR), were used to explore the basis for the synergism between CD3/alpha beta T cell receptor (TCR) and the CD2 antigen-derived signals in promoting proliferation of T cells. Northern blotting of RNA isolated from highly purified normal human T cells revealed that crosslinking of anti-TCR-1 (a mAb directed at a framework determinant of the TCR) and OKT11 (a mAb directed at the SRBC-binding epitope of the CD2 antigen) induced the expression of the interleukin-2 gene and the gene for IL-2 receptor alpha, mRNA phenotyping by PCR revealed that crosslinkage of TCR with the CD2 antigen, and not independent crosslinking of TCR or the CD2 antigen, results in the induction of IL-2, IL-2 receptors alpha and beta, and IL-4-specific transcripts. Highly purified CD4+ T cells, as well as CD8+ T cells proliferated by crosslinking TCR with CD2 antigen. Moreover, crosslinkage of TCR with the CD2 antigen and not of either antigen with the CD4 antigen (on the surface of CD4+ T cells) or the CD8 antigen (on the surface of CD8+ T cells) resulted in marked proliferation. Our demonstration that the CD2 antigen-derived signal(s) contribute to the expression of growth promoting genes elicited via the TCR, and that the CD2 antigen is more efficient compared with the CD4 or CD8 antigen in evoking T cell proliferation, suggests that autoimmunity as well as alloimmunity might be regulated by targeting the CD2 antigen.

  • The molecular basis for the synergism between the CD3/alpha beta T cell receptor and the CD2 antigen-derived signals in promoting T-cell proliferation.
    Transplantation, 1991
    Co-Authors: P. K. Sehajpal, Bernd Zanker, V.k. Murthi, A. Subramaniam, V. K. Sharma, D. Estin, E. Y. Skonik, Kenneth J. Wieder, Gerd Walz
    Abstract:

    Northern blot analysis and a highly sensitive methodology for mRNA phenotyping, polymerase chain reaction (PCR), were used to explore the basis for the synergism between CD3/alpha beta T cell receptor (TCR) and the CD2 antigen-derived signals in promoting proliferation of T cells. Northern blotting of RNA isolated from highly purified normal human T cells revealed that crosslinking of anti-TCR-1 (a mAb directed at a framework determinant of the TCR) and OKT11 (a mAb directed at the SRBC-binding epitope of the CD2 antigen) induced the expression of the interleukin-2 gene and the gene for IL-2 receptor alpha, mRNA phenotyping by PCR revealed that crosslinkage of TCR with the CD2 antigen, and not independent crosslinking of TCR or the CD2 antigen, results in the induction of IL-2, IL-2 receptors alpha and beta, and IL-4-specific transcripts. Highly purified CD4+ T cells, as well as CD8+ T cells proliferated by crosslinking TCR with CD2 antigen. Moreover, crosslinkage of TCR with the CD2 antigen and not of either antigen with the CD4 antigen (on the surface of CD4+ T cells) or the CD8 antigen (on the surface of CD8+ T cells) resulted in marked proliferation. Our demonstration that the CD2 antigen-derived signal(s) contribute to the expression of growth promoting genes elicited via the TCR, and that the CD2 antigen is more efficient compared with the CD4 or CD8 antigen in evoking T cell proliferation, suggests that autoimmunity as well as alloimmunity might be regulated by targeting the CD2 antigen.

P. K. Sehajpal - One of the best experts on this subject based on the ideXlab platform.

  • the molecular basis for the synergism between the cd3 alpha beta t cell receptor and the cd2 antigen derived signals in promoting t cell proliferation
    Transplantation, 1991
    Co-Authors: P. K. Sehajpal, Bernd Zanker, V.k. Murthi, A. Subramaniam, V. K. Sharma, D. Estin, E. Y. Skonik, Kenneth J. Wieder, Gerd Walz, M Fotino
    Abstract:

    Northern blot analysis and a highly sensitive methodology for mRNA phenotyping, polymerase chain reaction (PCR), were used to explore the basis for the synergism between CD3/alpha beta T cell receptor (TCR) and the CD2 antigen-derived signals in promoting proliferation of T cells. Northern blotting of RNA isolated from highly purified normal human T cells revealed that crosslinking of anti-TCR-1 (a mAb directed at a framework determinant of the TCR) and OKT11 (a mAb directed at the SRBC-binding epitope of the CD2 antigen) induced the expression of the interleukin-2 gene and the gene for IL-2 receptor alpha, mRNA phenotyping by PCR revealed that crosslinkage of TCR with the CD2 antigen, and not independent crosslinking of TCR or the CD2 antigen, results in the induction of IL-2, IL-2 receptors alpha and beta, and IL-4-specific transcripts. Highly purified CD4+ T cells, as well as CD8+ T cells proliferated by crosslinking TCR with CD2 antigen. Moreover, crosslinkage of TCR with the CD2 antigen and not of either antigen with the CD4 antigen (on the surface of CD4+ T cells) or the CD8 antigen (on the surface of CD8+ T cells) resulted in marked proliferation. Our demonstration that the CD2 antigen-derived signal(s) contribute to the expression of growth promoting genes elicited via the TCR, and that the CD2 antigen is more efficient compared with the CD4 or CD8 antigen in evoking T cell proliferation, suggests that autoimmunity as well as alloimmunity might be regulated by targeting the CD2 antigen.

  • The molecular basis for the synergism between the CD3/alpha beta T cell receptor and the CD2 antigen-derived signals in promoting T-cell proliferation.
    Transplantation, 1991
    Co-Authors: P. K. Sehajpal, Bernd Zanker, V.k. Murthi, A. Subramaniam, V. K. Sharma, D. Estin, E. Y. Skonik, Kenneth J. Wieder, Gerd Walz
    Abstract:

    Northern blot analysis and a highly sensitive methodology for mRNA phenotyping, polymerase chain reaction (PCR), were used to explore the basis for the synergism between CD3/alpha beta T cell receptor (TCR) and the CD2 antigen-derived signals in promoting proliferation of T cells. Northern blotting of RNA isolated from highly purified normal human T cells revealed that crosslinking of anti-TCR-1 (a mAb directed at a framework determinant of the TCR) and OKT11 (a mAb directed at the SRBC-binding epitope of the CD2 antigen) induced the expression of the interleukin-2 gene and the gene for IL-2 receptor alpha, mRNA phenotyping by PCR revealed that crosslinkage of TCR with the CD2 antigen, and not independent crosslinking of TCR or the CD2 antigen, results in the induction of IL-2, IL-2 receptors alpha and beta, and IL-4-specific transcripts. Highly purified CD4+ T cells, as well as CD8+ T cells proliferated by crosslinking TCR with CD2 antigen. Moreover, crosslinkage of TCR with the CD2 antigen and not of either antigen with the CD4 antigen (on the surface of CD4+ T cells) or the CD8 antigen (on the surface of CD8+ T cells) resulted in marked proliferation. Our demonstration that the CD2 antigen-derived signal(s) contribute to the expression of growth promoting genes elicited via the TCR, and that the CD2 antigen is more efficient compared with the CD4 or CD8 antigen in evoking T cell proliferation, suggests that autoimmunity as well as alloimmunity might be regulated by targeting the CD2 antigen.