IL-10 producing B lymphocytes in an experimental model of Chlamydia muridarum infection

SANCHEZ, L; GODOY, GJ; GOROSITO SERRAN, M; GRUPPI, A; MOTRICH, RD; RIVERO, VE

Mar del Plata

Congreso; LIX Reunión Científica Anual de la SAIC ? LXII Reunión Científica Anual de la SAI; 2014

Sociedad Argentina de Investigación Clínica y Sociedad Argentina de Inmunologia

Chlamydia trachomatis (CT) causes an important number of genital tract infections worldwide. Although after the infection a specific immune response is induced, some data suggest that its quality and/or intensity would not be adequate since disease is often persistent and recurrent. It has been postulated that Chlamydia would evade host defenses through different strategies, such as the induction of anti-inflammatory cytokines like IL10 and TGFß. Herein, we aimed to evaluate the role of IL10 after male genital tract infection with Chlamydia muridarum (Cm), a serovar that infects mice and produces a similar disease to that observed in humans. Cytokine production by splenocytes (MNC) from non-infected mice incubated with Cm was analyzed. MNC in vitro stimulated with heat inactivated Cm mostly secreted IL10 (IL10: 920±80pg/ml; IL6: 245±2 pg/ml; TNF: 130±20 pg/ml; IFN: 245 ± 2 pg/ml). FACS analyses revealed that the main producers of IL10 are CD45+CD19+ cells. Accordingly, magnetic beads purified B lymphocytes produced high levels of IL10 after in vitro stimulation with Cm. Experiments in which NOD mice were inoculated with Cm in the meatus urethra and then euthanized at different times post infection (pi) showed that MNC from infected mice produce the highest levels of IL10 at early times pi. Indeed, higher levels of IL10+CD45+CD19+ cells were found at 4 day pi, accompanied with low levels of IL10+CD45+CD3+ cells. Experiments using NOD and NOD-SCID mice showed a significant reduction in the IL10 amounts produced by MNC from infected NOD-SCID when compared to those from infected NOD mice (p