The Experts below are selected from a list of 4179 Experts worldwide ranked by ideXlab platform
Noriko Okada - One of the best experts on this subject based on the ideXlab platform.
-
a Complement Dependent Cytotoxicity enhancing anti cd20 antibody mediating potent antitumor activity in the humanized nod shi scid il 2rγ null mouse lymphoma model
Cancer Immunology Immunotherapy, 2010Co-Authors: Fumihiko Sato, Asahi Ito, Takashi Ishida, Fumiko Mori, Hisashi Takino, Atsushi Inagaki, Shigeru Kusumoto, Hirokazu Komatsu, Shinsuke Iida, Noriko OkadaAbstract:Engineering the Fc region of monoclonal antibodies (mAb) in order to enhance effector functions such as antibody-Dependent cellular Cytotoxicity and Complement-Dependent Cytotoxicity (CDC) is likely to a be promising approach for next-generation mAb therapy. Here, we report on such an antibody, 113F, a novel CDC-enhancing variant of rituximab, and determine the tumor-associated factors influencing susceptibility to 113F-induced CDC. The latter included the quantity of Complement inhibitors present, such as CD55 and CD59. We report that compared to rituximab, 113F mediated highly enhanced CDC against primary CD20-expressing lymphoma cells in vitro. Currently, a major problem in the field of immunotherapy research is the lack of suitable small animal models to evaluate human CDC in vivo. Therefore, we established a novel human tumor-bearing NOD/Shi-scid, IL-2Rγnull mouse model, in which human Complement functions as the CDC mediator. We demonstrated that rituximab exerted significant antitumor effects via human CDC in this humanized mouse. The finding of specific localization of human C1q on CD20-expressing tumor cell membranes was consistent with the observation that human CDC indeed contributed to the antitumor effect in this model. Moreover, 113F exerted significantly more potent antitumor effects than rituximab in this in vivo model. The detection of more abundant dense signals from C1q using 113F compared to rituximab was consistent with the concept that this reagent represented a CDC-enhancing mAb. In the near future, the efficacy of this type of CDC-enhancing antibody will be determined in clinical trials in humans.
Yasuhiko Nishioka - One of the best experts on this subject based on the ideXlab platform.
-
Chimeric anti-podoplanin antibody suppresses tumor metastasis through neutralization and antibody-Dependent cellular Cytotoxicity
2020Co-Authors: Mika K. Kaneko, Yuta Tsujimoto, Yoshihiko Sawa, Akiko Kunita, Masashi Fukayama, Shinji Abe, Yasuhiko Nishioka, Kaoru Goto, Yukinari KatoAbstract:Podoplanin is a platelet aggregation-inducing factor associated with tumor metastasis, malignant progression, and cancer stem cells. We produced a rat-human chimeric anti-podoplanin mAb, NZ-8, from rat anti-podoplanin mAb (NZ-1). Although both NZ-1 and NZ-8 possess high binding affinities and high neutralizing activities of platelet aggregation, the antibody-Dependent cellular Cytotoxicity and Complement-Dependent Cytotoxicity of NZ-8 were much higher than NZ-1. Furthermore, both NZ-1 and NZ-8 inhibited the growth of podoplanin-expressing tumors in vivo. Both NZ-1 and NZ-8 also suppressed hematogenous metastasis of podoplanin-expressing tumors. These results suggest that antipodoplanin mAbs suppressed hematogenous metastasis by both neutralization and antibody-Dependent cellular Cytotoxicity/Complement-Dependent Cytotoxicity activities. Targeting therapy to podoplanin-expressing tumors should be useful as a novel immunotherapy. (Cancer Sci, doi: 10.1111/j.1349-7006.2012.02385.x, 2012 P odoplanin is a platelet aggregation-inducing factor, and its expression has been reported in many tumors including malignant brain tumors, mesotheliomas, and squamous cell carcinoma. (1-10) Importantly, recent investigations have suggested that expression of podoplanin is associated with tumor metastasis, malignant progression, and epithelial-mesenchymal transition. (11-18) Podoplanin expression has also been reported to be associated with clinical outcome. (23) Because TICs are thought to be resistant to conventional therapies, and are responsible for relapse, targeting TICs could be a promising approach to cancer therapy. (24) Podoplanin has been reported to be a TIC marker; We previously produced an anti-podoplanin antibody, NZ-1. (5) NZ-1 should have not only high specificity and sensitivity but also high binding-affinity against podoplanin to be applied for radioimmunotherapy or immunotoxin therapy. Previous studies showed that NZ-1 is a suitable candidate for therapy against malignant gliomas because NZ-1 was highly internalized into glioma cell lines, and also well accumulated into tumors in vivo. (26) Moreover, NZ-1 inhibited tumor cellinduced platelet aggregation and tumor metastasis by its neutralizing activity. (12) However, it has not been clarified whether NZ-1 possesses antibody-Dependent cellular Cytotoxicity (ADCC) or Complement-Dependent Cytotoxicity (CDC) against podoplanin-expressing tumor cells. In this study, we produced rat-human chimeric anti-podoplanin antibody (NZ-8) from rat anti-podoplanin neutralizing antibody (NZ-1), and characterized NZ-8 activity in flow cytometry, Western blot, platelet aggregation, and ADCC/CDC analyses in vitro. Next, we investigated the antitumor and antimetastatic activities of the anti-podoplanin mAbs in vivo
-
antiglycopeptide mouse monoclonal antibody lpmab 21 exerts antitumor activity against human podoplanin through antibody Dependent cellular Cytotoxicity and Complement Dependent Cytotoxicity
Monoclonal antibodies in immunodiagnosis and immunotherapy, 2017Co-Authors: Yukinari Kato, Shinji Yamada, Akiko Kunita, Masashi Fukayama, Shinji Abe, Yasuhiko Nishioka, Miyuki Yanaka, Hiroaki Uchida, Hideaki Tahara, Takuro NakamuraAbstract:The interaction between podoplanin (PDPN) and C-type lectin-like receptor 2 (CLEC-2) is involved in tumor malignancy. We have established many monoclonal antibodies (mAbs) against human podoplanin using the cancer-specific mAb (CasMab) technology. LpMab-21, one of the mouse antipodoplanin mAbs, is of the IgG2a subclass, and its minimum epitope was determined to be Thr76-Arg79 of the human podoplanin. Importantly, sialic acid is linked to Thr76; therefore, LpMab-21 is an antiglycopeptide mAb (GpMab). In this study, we investigated whether LpMab-21 shows antibody-Dependent cellular Cytotoxicity (ADCC) and Complement-Dependent Cytotoxicity (CDC) against human podoplanin-expressing cancer cell lines in vitro and also studied its antitumor activities using a xenograft model. LpMab-21 showed high ADCC and CDC activities against not only podoplanin-expressing Chinese hamster ovary cells but also LN319 glioblastoma cells and PC-10 lung cancer cells, both of which endogenously express podoplanin. Furthermore, LpMab-21 decreased tumor growth in vivo, indicating that LpMab-21 could be useful for antibody therapy against human podoplanin-expressing cancers.
-
chimeric anti podoplanin antibody suppresses tumor metastasis through neutralization and antibody Dependent cellular Cytotoxicity
Cancer Science, 2012Co-Authors: Mika K. Kaneko, Yuta Tsujimoto, Yoshihiko Sawa, Akiko Kunita, Masashi Fukayama, Yasuhiko Nishioka, Kaoru Goto, Yukinari KatoAbstract:Podoplanin is a platelet aggregation-inducing factor associated with tumor metastasis, malignant progression, and cancer stem cells. We produced a rat–human chimeric anti-podoplanin mAb, NZ-8, from rat anti-podoplanin mAb (NZ-1). Although both NZ-1 and NZ-8 possess high binding affinities and high neutralizing activities of platelet aggregation, the antibody-Dependent cellular Cytotoxicity and Complement-Dependent Cytotoxicity of NZ-8 were much higher than NZ-1. Furthermore, both NZ-1 and NZ-8 inhibited the growth of podoplanin-expressing tumors in vivo. Both NZ-1 and NZ-8 also suppressed hematogenous metastasis of podoplanin-expressing tumors. These results suggest that anti-podoplanin mAbs suppressed hematogenous metastasis by both neutralization and antibody-Dependent cellular Cytotoxicity/Complement-Dependent Cytotoxicity activities. Targeting therapy to podoplanin-expressing tumors should be useful as a novel immunotherapy.
-
genetically engineered humanized anti ganglioside gm2 antibody against multiple organ metastasis produced by gm2 expressing small cell lung cancer cells
Cancer Science, 2011Co-Authors: Tadaaki Yamada, Yasuhiko Nishioka, Hideaki Bando, Shinji Takeuchi, Kenji Kita, Wei Wang, Shiro Akinaga, Saburo Sone, Seiji YanoAbstract:Small-cell lung cancer (SCLC) grows rapidly and metastasizes to multiple organs. We examined the antimetastatic effects of the humanized anti-ganglioside GM2 (GM2) antibodies, BIW-8962 and KM8927, compared with the chimeric antibody KM966, in a SCID mouse model of multiple organ metastases induced by GM2-expressing SCLC cells. BIW-8962 and KM8927 induced higher antibody-Dependent cellular Cytotoxicity and Complement-Dependent Cytotoxicity than KM966 against the GM2-expressing SCLC cell line SBC-3 in vitro. These humanized antibodies inhibited the production of multiple organ metastases, increased the number of apoptotic cells, and prolonged the survival of the SCID mice. Histological analyses using clinical specimens showed that SCLC cells expressed GM2. These findings suggest that humanized anti-GM2 antibodies could be therapeutically useful for controlling multiple organ metastases of GM2-expressing SCLC. (Cancer Sci 2011; 102: 2157–2163)
-
genetically engineered humanized anti ganglioside gm2 antibody against multiple organ metastasis produced by gm2 expressing small cell lung cancer cells
Cancer Science, 2011Co-Authors: Tadaaki Yamada, Yasuhiko Nishioka, Hideaki Bando, Shinji Takeuchi, Kenji Kita, Wei Wang, Shiro Akinaga, Saburo Sone, Seiji YanoAbstract:Small-cell lung cancer (SCLC) grows rapidly and metastasizes to multiple organs. We examined the antimetastatic effects of the humanized anti-ganglioside GM2 (GM2) antibodies, BIW-8962 and KM8927, compared with the chimeric antibody KM966, in a SCID mouse model of multiple organ metastases induced by GM2-expressing SCLC cells. BIW-8962 and KM8927 induced higher antibody-Dependent cellular Cytotoxicity and Complement-Dependent Cytotoxicity than KM966 against the GM2-expressing SCLC cell line SBC-3 in vitro. These humanized antibodies inhibited the production of multiple organ metastases, increased the number of apoptotic cells, and prolonged the survival of the SCID mice. Histological analyses using clinical specimens showed that SCLC cells expressed GM2. These findings suggest that humanized anti-GM2 antibodies could be therapeutically useful for controlling multiple organ metastases of GM2-expressing SCLC.
Ronald P Taylor - One of the best experts on this subject based on the ideXlab platform.
-
antibodies that efficiently form hexamers upon antigen binding can induce Complement Dependent Cytotoxicity under Complement limiting conditions
Journal of Immunology, 2016Co-Authors: Erika M Cook, Clive S Zent, Paul W H I Parren, Margaret A Lindorfer, Hilma J Van Der Horst, Simone C Oostindie, Frank J Beurskens, Janine Schuurman, Richard Burack, Ronald P TaylorAbstract:Recently, we demonstrated that IgG Abs can organize into ordered hexamers after binding their cognate Ags expressed on cell surfaces. This process is Dependent on Fc:Fc interactions, which promote C1q binding, the first step in classical pathway Complement activation. We went on to engineer point mutations that stimulated IgG hexamer formation and Complement-Dependent Cytotoxicity (CDC). The hexamer formation–enhanced (HexaBody) CD20 and CD38 mAbs support faster, more robust CDC than their wild-type counterparts. To further investigate the CDC potential of these mAbs, we used flow cytometry, high-resolution digital imaging, and four-color confocal microscopy to examine their activity against B cell lines and primary chronic lymphocytic leukemia cells in sera depleted of single Complement components. We also examined the CDC activity of alemtuzumab (anti-CD52) and mAb W6/32 (anti-HLA), which bind at high density to cells and promote substantial Complement activation. Although we observed little CDC for mAb-opsonized cells reacted with sera depleted of early Complement components, we were surprised to discover that the Hexabody mAbs, as well as ALM and W6/32, were all quite effective at promoting CDC in sera depleted of individual Complement components C6 to C9. However, neutralization studies conducted with an anti-C9 mAb verified that C9 is required for CDC activity against cell lines. These highly effective Complement-activating mAbs efficiently focus activated Complement components on the cell, including C3b and C9, and promote CDC with a very low threshold of MAC binding, thus providing additional insight into their enhanced efficacy in promoting CDC.
-
real time analysis of the detailed sequence of cellular events in mab mediated Complement Dependent Cytotoxicity of b cell lines and of chronic lymphocytic leukemia b cells
Molecular Immunology, 2016Co-Authors: Margaret A Lindorfer, Clive S Zent, Paul W H I Parren, Erika M Cook, Frank J Beurskens, Janine Schuurman, Richard Burack, Jillian C Tupitza, Rob N De Jong, Ronald P TaylorAbstract:Complement-Dependent Cytotoxicity is an important mechanism of action of certain mAbs used in cancer immunotherapy, including ofatumumab and rituximab. However, the detailed sequence of cellular changes that occur in nucleated cells attacked by mAb and Complement has not been delineated. Recently developed CD20 mAbs, engineered to form hexamers on binding to cells, react with B-cells in serum, chelate C1q, and then activate Complement and promote cell killing considerably more effectively than their wild-type precursors. We used these engineered mAbs as a model to investigate the sequence of events that occur when mAbs bind to B-cell lines and to primary cells from patients with chronic lymphocytic leukemia and then activate Complement. Based on four-color confocal microscopy real-time movies and high resolution digital imaging, we find that after CD20 mAb binding and C1q uptake, C3b deposits on cells, followed by Ca(2+) influx, revealed by bright green signals generated on cells labeled with FLUO-4, a Ca(2+) indicator. The bright FLUO-4/Ca(2+) signal fades, replaced by punctate green signals in mitochondria, indicating Ca(2+) localization. This step leads to mitochondrial poisoning followed by cell death. The entire sequence is completed in <2 min for hexamerization-enhanced CD20 mAb-mediated killing. To our knowledge this is the first time the entire process has been characterized in detail in real time. By identifying multiple discrete steps in the cytotoxic pathway for nucleated cells our findings may inform future development and more effective application of Complement-fixing mAbs to cancer treatment.
-
induced resistance to ofatumumab mediated cell clearance mechanisms including Complement Dependent Cytotoxicity in chronic lymphocytic leukemia
Journal of Immunology, 2014Co-Authors: Nisar A Baig, Betsy Laplant, Tait D. Shanafelt, Margaret A Lindorfer, Ronald P Taylor, Amy K Church, Adam Pettinger, Grzegorz S Nowakowski, Clive S ZentAbstract:Ofatumumab (OFA), a human CD20-targeting mAb, kills B lymphocytes using the innate immune system including Complement-Dependent Cytotoxicity (CDC). The efficacy of OFA in patients with chronic lymphocytic leukemia (CLL) is limited by drug resistance, which is not well characterized. To better understand mechanisms of resistance, we prospectively studied CLL cells isolated from blood samples collected before and after in vivo exposure to the initial dose of OFA therapy in 25 patients undergoing their first treatment for progressive CLL. As previously reported, OFA therapy rapidly decreased the absolute lymphocyte count, CD20 expression by CLL cells, and serum Complement levels. We now show that after administration of the first dose of OFA, there was a modest rebound in the absolute lymphocyte count and serum Complement levels, but substantial ongoing loss of CD20 expression by CLL cells. These post-OFA treatment CLL cells were highly resistant to OFA-mediated CDC but retained sensitivity to alemtuzumab-mediated CDC in vitro. Posttherapy serum OFA levels correlated inversely with both the amount of pretreatment circulating cell-bound CD20 and with the decrease in this value following treatment. In vitro OFA-mediated CDC did not predict clinical responses, and the patients with first-dose reactions to OFA did not have markers of increased Complement activation in vivo. We propose that optimal efficacy of CD20- targeted therapy for CLL requires determining an mAb dose size and frequency that optimizes CLL killing without exceeding the capacity of the cytotoxic mechanisms and thus minimizes loss of CD20 expression in the surviving CLL cells.
-
cd20 mab mediated Complement Dependent Cytotoxicity of tumor cells is enhanced by blocking the action of factor i
Antibodies, 2013Co-Authors: Margaret A Lindorfer, Paul V Beum, Ronald P TaylorAbstract:The CD20 mAbs, rituximab (RTX) and ofatumumab (OFA), have been used with success in the clinic in the treatment of B cell malignancies. These mAbs can eliminate B cells only by utilizing the body’s immune effector mechanisms, and there is considerable evidence that OFA is particularly effective at eliminating B cells by mediating Complement Dependent Cytotoxicity (CDC). However, effector mechanisms such as Complement can be exhausted or down-regulated. Therefore, several approaches are being investigated with the goal of increasing CDC mediated by these mAbs. We reported that when patients with chronic lymphocytic leukemia (CLL) are treated with RTX or with OFA, Complement is rapidly activated on circulating, targeted CLL B cells. However, a substantial fraction of these cells escape CDC and clearance due to degradation of covalently deposited active C3b fragments to inactive fragments iC3b and C3d. This process is mediated by a plasma protease, Factor I. Therefore, a rational approach for increasing CDC would be to block this reaction by inhibiting Factor I with a neutralizing mAb. Indeed, we have demonstrated that use of neutralizing mAb A247, specific for factor I, significantly and substantially increases CD20 mAb-mediated CDC of both cell lines and of primary CLL cells in vitro.
-
binding of submaximal c1q promotes Complement Dependent Cytotoxicity cdc of b cells opsonized with anti cd20 mabs ofatumumab ofa or rituximab rtx considerably higher levels of cdc are induced by ofa than by rtx
Journal of Immunology, 2009Co-Authors: Andrew W Pawluczkowycz, Paul W H I Parren, Margaret A Lindorfer, Paul V Beum, Frank J Beurskens, Jan G J Van De Winkel, Ronald P TaylorAbstract:The CD20 mAb ofatumumab (OFA) is more effective than rituximab (RTX) in promoting Complement-Dependent Cytotoxicity (CDC) of B cells via the classical pathway (CP) of Complement. CP activation is initiated by C1q binding to cell-bound IgG. Therefore, we examined the role of C1q in the dynamics of Complement activation and CDC of B cell lines and primary cells from patients with chronic lymphocytic leukemia, reacted with OFA or RTX. C1q binding, Complement activation, and colocalization of C1q with cell-bound mAbs were determined by flow cytometry and high-resolution digital imaging. C1q binds avidly to OFA-opsonized Raji and Daudi cells (K(D) = 12-16 nM) and colocalizes substantially with cell-bound OFA. Cells opsonized with OFA undergo high levels of Complement activation and CDC in C1q-depleted serum supplemented with low concentrations of C1q. Under comparable conditions, RTX-opsonized cells bind less C1q; in addition, even when higher concentrations of C1q are used to achieve comparable C1q binding to RTX-opsonized cells, less Complement activation and CDC are observed. Greater CDC induced by OFA may occur because C1q is bound in close proximity and with high avidity to OFA, resulting in effective CP activation. Moreover, OFA binds to the small, extracellular CD20 loop, placing the mAb considerably closer to the cell membrane than does RTX. This may facilitate effective capture and concentration of activated Complement components closer to the cell membrane, potentially shielding them from inactivation by fluid phase agents and promoting efficient generation of the membrane attack complex.
Yukinari Kato - One of the best experts on this subject based on the ideXlab platform.
-
Chimeric anti-podoplanin antibody suppresses tumor metastasis through neutralization and antibody-Dependent cellular Cytotoxicity
2020Co-Authors: Mika K. Kaneko, Yuta Tsujimoto, Yoshihiko Sawa, Akiko Kunita, Masashi Fukayama, Shinji Abe, Yasuhiko Nishioka, Kaoru Goto, Yukinari KatoAbstract:Podoplanin is a platelet aggregation-inducing factor associated with tumor metastasis, malignant progression, and cancer stem cells. We produced a rat-human chimeric anti-podoplanin mAb, NZ-8, from rat anti-podoplanin mAb (NZ-1). Although both NZ-1 and NZ-8 possess high binding affinities and high neutralizing activities of platelet aggregation, the antibody-Dependent cellular Cytotoxicity and Complement-Dependent Cytotoxicity of NZ-8 were much higher than NZ-1. Furthermore, both NZ-1 and NZ-8 inhibited the growth of podoplanin-expressing tumors in vivo. Both NZ-1 and NZ-8 also suppressed hematogenous metastasis of podoplanin-expressing tumors. These results suggest that antipodoplanin mAbs suppressed hematogenous metastasis by both neutralization and antibody-Dependent cellular Cytotoxicity/Complement-Dependent Cytotoxicity activities. Targeting therapy to podoplanin-expressing tumors should be useful as a novel immunotherapy. (Cancer Sci, doi: 10.1111/j.1349-7006.2012.02385.x, 2012 P odoplanin is a platelet aggregation-inducing factor, and its expression has been reported in many tumors including malignant brain tumors, mesotheliomas, and squamous cell carcinoma. (1-10) Importantly, recent investigations have suggested that expression of podoplanin is associated with tumor metastasis, malignant progression, and epithelial-mesenchymal transition. (11-18) Podoplanin expression has also been reported to be associated with clinical outcome. (23) Because TICs are thought to be resistant to conventional therapies, and are responsible for relapse, targeting TICs could be a promising approach to cancer therapy. (24) Podoplanin has been reported to be a TIC marker; We previously produced an anti-podoplanin antibody, NZ-1. (5) NZ-1 should have not only high specificity and sensitivity but also high binding-affinity against podoplanin to be applied for radioimmunotherapy or immunotoxin therapy. Previous studies showed that NZ-1 is a suitable candidate for therapy against malignant gliomas because NZ-1 was highly internalized into glioma cell lines, and also well accumulated into tumors in vivo. (26) Moreover, NZ-1 inhibited tumor cellinduced platelet aggregation and tumor metastasis by its neutralizing activity. (12) However, it has not been clarified whether NZ-1 possesses antibody-Dependent cellular Cytotoxicity (ADCC) or Complement-Dependent Cytotoxicity (CDC) against podoplanin-expressing tumor cells. In this study, we produced rat-human chimeric anti-podoplanin antibody (NZ-8) from rat anti-podoplanin neutralizing antibody (NZ-1), and characterized NZ-8 activity in flow cytometry, Western blot, platelet aggregation, and ADCC/CDC analyses in vitro. Next, we investigated the antitumor and antimetastatic activities of the anti-podoplanin mAbs in vivo
-
antiglycopeptide mouse monoclonal antibody lpmab 21 exerts antitumor activity against human podoplanin through antibody Dependent cellular Cytotoxicity and Complement Dependent Cytotoxicity
Monoclonal antibodies in immunodiagnosis and immunotherapy, 2017Co-Authors: Yukinari Kato, Shinji Yamada, Akiko Kunita, Masashi Fukayama, Shinji Abe, Yasuhiko Nishioka, Miyuki Yanaka, Hiroaki Uchida, Hideaki Tahara, Takuro NakamuraAbstract:The interaction between podoplanin (PDPN) and C-type lectin-like receptor 2 (CLEC-2) is involved in tumor malignancy. We have established many monoclonal antibodies (mAbs) against human podoplanin using the cancer-specific mAb (CasMab) technology. LpMab-21, one of the mouse antipodoplanin mAbs, is of the IgG2a subclass, and its minimum epitope was determined to be Thr76-Arg79 of the human podoplanin. Importantly, sialic acid is linked to Thr76; therefore, LpMab-21 is an antiglycopeptide mAb (GpMab). In this study, we investigated whether LpMab-21 shows antibody-Dependent cellular Cytotoxicity (ADCC) and Complement-Dependent Cytotoxicity (CDC) against human podoplanin-expressing cancer cell lines in vitro and also studied its antitumor activities using a xenograft model. LpMab-21 showed high ADCC and CDC activities against not only podoplanin-expressing Chinese hamster ovary cells but also LN319 glioblastoma cells and PC-10 lung cancer cells, both of which endogenously express podoplanin. Furthermore, LpMab-21 decreased tumor growth in vivo, indicating that LpMab-21 could be useful for antibody therapy against human podoplanin-expressing cancers.
-
chimeric anti podoplanin antibody suppresses tumor metastasis through neutralization and antibody Dependent cellular Cytotoxicity
Cancer Science, 2012Co-Authors: Mika K. Kaneko, Yuta Tsujimoto, Yoshihiko Sawa, Akiko Kunita, Masashi Fukayama, Yasuhiko Nishioka, Kaoru Goto, Yukinari KatoAbstract:Podoplanin is a platelet aggregation-inducing factor associated with tumor metastasis, malignant progression, and cancer stem cells. We produced a rat–human chimeric anti-podoplanin mAb, NZ-8, from rat anti-podoplanin mAb (NZ-1). Although both NZ-1 and NZ-8 possess high binding affinities and high neutralizing activities of platelet aggregation, the antibody-Dependent cellular Cytotoxicity and Complement-Dependent Cytotoxicity of NZ-8 were much higher than NZ-1. Furthermore, both NZ-1 and NZ-8 inhibited the growth of podoplanin-expressing tumors in vivo. Both NZ-1 and NZ-8 also suppressed hematogenous metastasis of podoplanin-expressing tumors. These results suggest that anti-podoplanin mAbs suppressed hematogenous metastasis by both neutralization and antibody-Dependent cellular Cytotoxicity/Complement-Dependent Cytotoxicity activities. Targeting therapy to podoplanin-expressing tumors should be useful as a novel immunotherapy.
Fumihiko Sato - One of the best experts on this subject based on the ideXlab platform.
-
a Complement Dependent Cytotoxicity enhancing anti cd20 antibody mediating potent antitumor activity in the humanized nod shi scid il 2rγnull mouse lymphoma model
Blood, 2010Co-Authors: Asahi Ito, Fumihiko Sato, Takashi Ishida, Fumiko Mori, Hisashi Takino, Atsushi Inagaki, Shigeru Kusumoto, Hirokazu Komatsu, Shinsuke Iida, Hiroshi InagakiAbstract:Abstract Abstract 423 Purpose: Engineering the Fc region of monoclonal antibodies (mAb) to enhance effector functions is likely to be a promising approach for next-generation mAb therapy. 113F, a Complement-Dependent Cytotoxicity-(CDC)-enhancing variant of rituximab is such an antibody (Cancer Res 2008;68:3863-72). The first of the three major aims of the present study was to identify tumor-associated factors influencing tumor susceptibility to 113F-induced CDC, especially focusing on Complement regulatory proteins (CRPs). The second aim of the present study was to compare 113F-induced CDC against primary lymphoma cells with rituximab in vitro. A current crucial problem in the field of human immunotherapy research, including antibody therapy, is the lack of suitable small animal models for in vivo preclinical testing. With respect to antibody-Dependent cellular Cytotoxicity (ADCC), we have established a human tumor-bearing mouse model, using NOD/Shi-scid, IL-2Rγnull (NOG) mice as recipients, in which human immune cells are engrafted and mediate ADCC (Cancer Immunol Immunother 2009;58:1195-206, J Immunol. 2009;183:4782-91). On the other hand, there is no mouse model in which human CDC can be evaluated. Thus, the third and final aim of the present study was to establish a mouse model in which it is human Complement that mediates CDC against human tumor cells.Using this model, we assessed the therapeutic potential of 113F in comparison with rituximab. Experimental Design: Rituximab- and 113F-induced human CDC was compared in vitro, and in vivo using NOG mice with human Complement. Result: First, we determined that tumor-associated factors influencing tumor susceptibility to 113F-induced CDC included the quantity of CRPs such as CD55 and CD59 on the cell surface, as observed in rituximab-induced CDC. Second, we found that 113F mediated highly enhanced CDC against primary CD20-expressing lymphoma cells from patients, greater than rituximab. Finally, a novel human tumor-bearing mouse model has been developed in which human Complement functions in CDC. NOG mouse serum is defective in its capacity to induce CDC against human cells, and endogenous immune cells from NOG mice are unable to mediate ADCC of therapeutic antibodies with an Fc region consisting of human IgG. Thus, we were able to evaluate purely human CDC without interference from endogenous mouse immune cells or Complement-mediated mAb induced antitumor effects in this NOG mouse model. The present observation of significant therapeutic efficacy of rituximab together with pooled human serum (PHS) compared to rituximab with inactivated PHS indicated that human Complement does function in rituximab-induced CDC in these mice in vivo. The finding of specific localization of human C1q on CD20-expressing tumor cell membranes indicated that human CDC indeed contributed to the antitumor effect in this model. In addition, enhanced therapeutic efficacy of 113F together with PHS compared to rituximab with PHS in this mouse model was observed in vivo. In the cell proliferation assay, viability of the target cell line was not affected by rituximab or 113F alone, and thus no significant difference between these mAbs was observed in vitro. Therefore, the present in vivo observation emphasizes the concept of this type of CDC-enhancing antibody. Furthermore, the more abundant, denser signals of C1q at the tumor cell membrane in these human serum-bearing mice receiving 113F compared with rituximab, are consistent with the Fc region of the former having a much higher C1q binding affinity than the latter. These findings are concordant with the present observation of the greater therapeutic efficacy of 113F compared to rituximab in vivo. Conclusion: This animal model overcomes the limitations of preclinical in vivo investigations of CDC caused by species incompatibilities between humans and mice. This model also makes it possible to reconstitute the human Complement system during mAb-based immunotherapy and to perform more appropriate preclinical evaluations of novel therapeutic mAb which mediate CDC. In the present study, highly enhanced human CDC mediated by this type of CDC-enhancing mAb was demonstrated both in vitro and in a humanized mouse model in vivo. In the near future, the efficacy of the type of CDC-enhancing antibody described here will be established in planned clinical trials in humans. Disclosures: No relevant conflicts of interest to declare.
-
a Complement Dependent Cytotoxicity enhancing anti cd20 antibody mediating potent antitumor activity in the humanized nod shi scid il 2rγ null mouse lymphoma model
Cancer Immunology Immunotherapy, 2010Co-Authors: Fumihiko Sato, Asahi Ito, Takashi Ishida, Fumiko Mori, Hisashi Takino, Atsushi Inagaki, Shigeru Kusumoto, Hirokazu Komatsu, Shinsuke Iida, Noriko OkadaAbstract:Engineering the Fc region of monoclonal antibodies (mAb) in order to enhance effector functions such as antibody-Dependent cellular Cytotoxicity and Complement-Dependent Cytotoxicity (CDC) is likely to a be promising approach for next-generation mAb therapy. Here, we report on such an antibody, 113F, a novel CDC-enhancing variant of rituximab, and determine the tumor-associated factors influencing susceptibility to 113F-induced CDC. The latter included the quantity of Complement inhibitors present, such as CD55 and CD59. We report that compared to rituximab, 113F mediated highly enhanced CDC against primary CD20-expressing lymphoma cells in vitro. Currently, a major problem in the field of immunotherapy research is the lack of suitable small animal models to evaluate human CDC in vivo. Therefore, we established a novel human tumor-bearing NOD/Shi-scid, IL-2Rγnull mouse model, in which human Complement functions as the CDC mediator. We demonstrated that rituximab exerted significant antitumor effects via human CDC in this humanized mouse. The finding of specific localization of human C1q on CD20-expressing tumor cell membranes was consistent with the observation that human CDC indeed contributed to the antitumor effect in this model. Moreover, 113F exerted significantly more potent antitumor effects than rituximab in this in vivo model. The detection of more abundant dense signals from C1q using 113F compared to rituximab was consistent with the concept that this reagent represented a CDC-enhancing mAb. In the near future, the efficacy of this type of CDC-enhancing antibody will be determined in clinical trials in humans.