T cell apoptosis and induction of Foxp3+ regulatory T cells underlie the therapeutic efficacy of CD4 blockade in experimental autoimmune encephalomyelitis.
The pathogenesis of multiple sclerosis requires the participation of effector neuroantigen-specific T cells. Thus, T cell targeting has been proposed as a promising therapeutic strategy. However, the mechanism underlying effective disease prevention following T cell targeting remains incompletely known. We found, using several TCR-transgenic strains, that CD4 blockade is effective in preventing experimental autoimmune encephalopathy and in treating mice after the disease onset. The mechanism does not rely on direct T cell depletion, but the anti-CD4 mAb prevents the proliferation of naive neuroantigen-specific T cells, as well as acquisition of effector Th1 and Th17 phenotypes. Simultaneously, the mAb favors peripheral conversion of Foxp3(+) regulatory T cells. Pre-existing effector cells, or neuroantigen-specific cells that undergo cell division despite the presence of anti-CD4, are committed to apoptosis. Therefore, protection from experimental autoimmune encephalopathy relies on a combination of dominant mechanisms grounded on regulatory T cell induction and recessive mechanisms based on apoptosis of neuropathogenic cells. We anticipate that the same mechanisms may be implicated in other T cell-mediated autoimmune diseases that can be treated or prevented with Abs targeting T cell molecules, such as CD4 or CD3.
Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, 1649-028 Lisbon, Portugal.
Joana
J
Duarte
Nadège
N
Carrié
Vanessa G
VG
Oliveira
Catarina
C
Almeida
Ana
A
Agua-Doce
Lénia
L
Rodrigues
J Pedro
JP
Simas
Lennart T
LT
Mars
Luis
L
Graca
D019264:Adoptive Transfer; D000818:Animals; D017209:Apoptosis / Q000276:immunology*; D015704:CD4 Antigens / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000276:immunology*; D005434:Flow Cytometry; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
D015704:CD4 Antigens