Influence of cathpesin-L on CD4+ regulatory T cells peripheral homeostasis

CAMICIA GABRIELA; BADANO NOEL; MAGLIOCO ANDREA; COSTA HECTOR; PIAZZON ISABEL; NEPOMNASCHY IRENE

Buenos Aires

Congreso; First French-Argentine Immunology Congress; 2010

Sociedad Argentina de Inmunologia

CD4+CD25+Foxp3+ regulatory T cells play a pivotal role in the maintenance of peripheral tolerance and immune homeostasis. We had previously shown that cathepsin-L deficient mice (CTSLnkt) show increased absolute number of CD4+ regulatory T cells in peripheral lymph nodes (LN) whereas the number of CD4+Foxp3+ thymic cells was shown to be decreased. In this study, we investigated the impact of cathepsin-L on CD4+ regulatory T cell peripheral homeostasis by analyzing CD4+CD25+ (Treg) cell turnover in CTSLnkt mice. To determine the proliferation rate of LN Treg subsets, 5-bromo-2- deoxyuridine (BrdU) was injected for 7 days. FACS analysis showed that both the CTSLnkt Treg and CD4+CD25- subsets showed a significant increase in the % of BrdU+ cells as compared to wild type (mean % BrdU+/Treg cells ± DS: 22±3 vs 12±1, p