Functional analysis of Foxp3 and CTLA-4 expressing HTLV-1-infected cells in a rat model

Increased expression of the regulatory T cell-associated marker CTLA-4 in bovine leukemia virus infection

“…The presence of CTLA-4 on CD4 + CD25 + Foxp3 + T cells has been regarded as an explanation for immunosuppression during disease progression in infections with HIV, SIV, HCV, and Trypanosoma and in B cell non-Hodgkin lymphoma (Boasso et al, 2007;Graefe et al, 2004;Kaufmann and Walker, 2009;Leng et al, 2002;Nakamoto et al, 2009;Yang et al, 2006;Zaunders et al, 2006;Zhang et al, 2010). In the model of HTLV-I-related BLV, Foxp3-and CTLA-4-expressing HTLV-I-infected cells suppressed the proliferation of naïve T cells that were stimulated with anti-CD3 antibody (Takayanagi et al, 2009). In the present study, bovine CTLA-4 mRNA was predominantly expressed in CD4 + T cells among cell populations from BLV-infected cattle (data not shown), and the expression of CTLA-4 in CD4 + cells was positively correlated with Foxp3, the most reliable marker for Treg, suggesting that CTLA-4 was expressed by Tregs.…”

HTLV-1-associated infective dermatitis demonstrates low frequency of FOXP3-positive T-regulatory lymphocytes

“…Our findings of reduced Tregs in skin of patients with ID, an inflammatory condition similar to HAM/TSP, are in agreement with that observation. The reported relationship between FoxP3 expression and ATLL progression [33] may be explained by acquisition of Treg like function of ATLL cells or HTLV-1 infected cells expressing FoxP3, which would impair cellular immune responses perpetuating and exacerbating HTLV-1-associated diseases [33].…”

Expression analysis of Foxp3 in T cells from bovine leukemia virus infected cattle

“…As an alternative hypothesis, Treg suppresses immune responses through direct cell–cell contact in a process that is dependent on signaling via CTLA‐4 . Indeed, Foxp3 + CTLA‐4 + expressing HTLV‐1‐infected cells suppressed proliferation of naïve T cells that were stimulated with anti‐CD3 antibody . However, there is no information about bovine CTLA‐4 and its associations with disease.…”