A humanized anti-human Fas antibody, R-125224, induces apoptosis in type I activated lymphocytes but not in type II cells

• Published in: International immunology Vol. 18; no. 1; pp. 113 - 124
• Main Authors: Nakayama, Junichi, Ogawa, Yukie, Yoshigae, Yasushi, Onozawa, Yoshiko, Yonemura, Akiko, Saito, Motoko, Ichikawa, Kimihisa, Yamoto, Takashi, Komai, Tomoaki, Tatsuta, Toru, Ohtsuki, Masahiko
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.01.2006; Oxford Publishing Limited (England)
• Subjects: 3′-dihexyloxacarbocyanine iodide; activated human lymphocytes; ALT alanine aminotransferase; Animals; anti-autoimmune disease therapy; anti-FLAG anti-FLAG M2 antibody; anti-hIgG anti-human IgG; Antibodies, Monoclonal - immunology; Antibodies, Monoclonal - pharmacology; APC antigen-presenting cell; Apoptosis - drug effects; Apoptosis - immunology; AST aspartate aminotransferase; Bmax maximum binding; CD3 Complex - immunology; CL collagen; CMTMR Cell Tracker™ Orange CMTMR; DiOC6 3; DISC; DISC death-inducing signaling complex; FADD Fas-associated death domain; fas Receptor - immunology; FasL Fas ligand; Hepatocytes - immunology; Humans; Immunologic Capping - drug effects; Immunologic Capping - immunology; Jurkat Cells; lipid rafts; Lymphocyte Activation - drug effects; Lymphocyte Activation - immunology; Mice; Mice, SCID; PI propidium iodide; RA rheumatoid arthritis; SCID-bg C·B-17/Icr Crj-scid bgBR; sFasL soluble Fas ligand; Signal Transduction - drug effects; Signal Transduction - immunology; Th1 Cells - immunology; Th2 Cells - immunology; TNF tumor necrosis factor; ΔΨm mitochondrial transmembrane potential
• ISSN: 0953-8178; 1460-2377
• DOI: 10.1093/intimm/dxh353

Fas-mediated apoptosis plays an important role in the immune system, including the elimination of autoreactive lymphoid cells. The Fas-mediated signaling pathway is classified into two types, type I and type II, in human lymphoid cell lines. We investigated whether a humanized anti-human Fas mAb, R-125224, has cell selectivity in induction of apoptosis. R-125224 induced apoptosis in H9 cells, SKW6.4 cells and activated human lymphocytes when cross-linked with anti-human IgG. On the other hand, R-125224 did not induce apoptosis in HPB-ALL cells, Jurkat cells or human hepatocytes. By analysis of death-inducing signaling complex formation, it was demonstrated that R-125224 induced apoptosis selectively in type I cells but not in type II cells. Type I cells also expressed more Fas and had more Fas-clustering activity than type II cells. Moreover, co-localization of these clusters and GM1, which is an sphingoglycolipid associated with lipid rafts, was detected. It was also shown that R-125224 treatment could reduce the number of activated human CD3+Fas+ cells in a SCID mouse model in vivo. Thus, we demonstrated that R-125224 induces apoptosis specifically in type I cells in vitro and in vivo.