Characterization of Foxp3+ regulatory T cells in experimental autoimmune orchitis

PATRICIA JACOBO; VANESA ANABELLA GUAZZONE; CECILIA VALERIA PÉREZ; SABRINA JARAZO DIETRICH; MAR&2377A SUSANA THEASS; LIVIA LUSTIG

Buenos Aires

Congreso; First French-Argentine Immunology Congress; 2010

Sociedad Argentina de Inmunologia

Experimental autoimmune orchitis (EAO) is a useful model to study chronic testicular inflammation and infertility. EAO is characterized by an interstitial lymphomononuclear cell infiltrate and a severe damage of seminiferous tubules (ST) that undergo apoptosis and sloughing. We previously reported an increased number of infiltrating Foxp3+ regulatory T cells (Treg) in the testis of EAO rats. In the present work, we studied the localization and suppressive and proliferative capacity of Foxp3+ Treg in the testis of rats undergoing autoimmune orchitis. EAO was induced by active immunization with testicular homogenate and adjuvants. Control (C) immunized with adjuvants and normal (N), non-treated rats were also used. By immunofluorescence we observed clusters of Foxp3+ cells in the subalbuginea area of the testicular interstitium, in close proximity to damaged ST. For functional analysis, CD4+ CD25high CD27+ T cells containing more than 90% of Foxp3+ cells were isolated from testis draining lymph nodes of N, C and EAO rats by FACS sorting and analyzed for their suppressive activity in vitro. All groups of Treg were found to suppress effector T cell proliferation induced by testicular antigens. However, EAO Treg were more efficient than those of N and C rats (suppressive activity, N Treg: 28%, C Treg: 28%, EAO Treg: 61%, data are representative of three independent experiments). Also, these Treg express TGF-â1. By bromodeoxiuridine incorporation assay we detected an increased number of proliferating Foxp3+ Treg in the testis of EAO compared to N and C rats (N: 0,09±0,01; C: 0,18±0,01; E: 1,8±0,2 (x105)*, *p