title: Treatment with depleting CD4 monoclonal antibody results in a preferential loss of circulating naive T cells but does not affect IFN-gamma secreting TH1 cells in humans.
abstract: CD4(pos) TH1 T cells are considered to play a central role in a number of human autoimmune diseases such as rheumatoid arthritis (RA) and multiple sclerosis. Experimental treatment protocols aimed at selectively eliminating CD4(pos) T cells thus far have yielded disappointing clinical results. Here we analyzed phenotype and function of circulating T cells in multiple sclerosis patients treated with the chimeric CD4 mAb cM-T412 in a randomized, double-blind, placebo-controlled, magnetic resonance imaging-monitored phase II trial. Treatment resulted in a long-lasting depletion of CD4(pos) T cells but did not affect CD8(pos) T cell numbers. Analysis of CD4(pos) subpopulations showed that unprimed, CD45RA(pos)/R0(neg) lymphocytes were approximately three times more sensitive to the mAb than primed, CD45RA(neg)/R0(pos) T cells. Notably, within the CD45RA(pos) subset, T cells with phenotypic evidence of prior activation, i.e., expressing Fas, were relatively insensitive to cM-T412, compared with Fas(neg) cells. Remarkably, while a decrease in the number of IL-4-producing T helper 2 (TH2)-type cells in the anti-CD4 treated group was observed, numbers of IFN-gamma-producing T helper 1 (TH1)-type cells remained stable, resulting in a significant increase in the TH1/TH2 ratio. Our data show that treatment with depleting CD4 mAb does not eliminate the cells most strongly involved in the disease process, i.e., primed, IFN-gamma-producing TH1-type cells, and may therefore give an explanation for the lack of beneficial clinical effects of depleting CD4 mAb in human chronic autoimmune disease.
authors.affiliation: Department of Clinical Viro-Immunology, Laboratory of Experimental and Clinical Immunology of the University of Amsterdam, The Netherlands.
authors.forename: M H
authors.initials: MH
authors.lastname: Rep
authors.forename: B W
authors.initials: BW
authors.lastname: van Oosten
authors.forename: M T
authors.initials: MT
authors.lastname: Roos
authors.forename: H J
authors.initials: HJ
authors.lastname: Adèr
authors.forename: C H
authors.initials: CH
authors.lastname: Polman
authors.forename: R A
authors.initials: RA
authors.lastname: van Lier
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D015704:CD4 Antigens / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis / Q000276:immunology; D015847:Interleukin-4 / Q000096:biosynthesis / Q000276:immunology; D017493:Leukocyte Common Antigens / Q000276:immunology; D008212:Lymphocyte Depletion; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000276:immunology / Q000628:therapy*; D016176:T-Lymphocyte Subsets / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology* / Q000378:metabolism; D018418:Th2 Cells / Q000276:immunology / Q000378:metabolism; D019014:fas Receptor / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D015704:CD4 Antigens; D019014:fas Receptor; D015847:Interleukin-4; D007371:Interferon-gamma; D017493:Leukocyte Common Antigens