NEUTROPHILS RECRUITMENT MODULATEST CELL RESPONSE IN LYMPH NODES

CASTELL, SOFÍA D ; HARMAN, MARÍA F ; GORLINO, CAROLINA V ; MORÓN, VICTOR G ; MALETTO, BELKYS A; PISTORESI, MARÍA C

Buenos Aires

Congreso; LXIII Reunión anual de SAI; 2015

Previously we demonstrated that when mice were immunized with OVA emulsified in Freund?scomplete adjuvant on day 0, boosted with OVA emulsified in Freund?s incomplete adjuvant onday15, and 10 days after injected with OVA-FITC in the footpad, the main OVA-FITC+cellsrecruited in draining popliteal lymph nodes (D-poLNs) were neutrophils whereas these cells wereundetectable on control popliteal lymph nodes (ND-poLNs) corresponding to the footpad injectedwith saline solution(D-poLNs 9,9±2% vs. ND-poLNs 0,3±0,1%;p<0.001). This influx was dependenton an antigen-specific response, since the formation of OVA/anti-OVA immunocomplex (IC) isrequired.In the present study we evaluate the influence of the presence of neutrophils activated with IC on Tcell response.In order to perform in vitro proliferation assays, CD4+T-cells purified from OTII micewere co-cultured with cells from D and ND-poLNsobtainedfrom immunized mice 6 h after footpadinjection. Thesecellswere stimulated with OVA for 72 h and proliferation was determined by CFSEdilution. We observed that in the presence of neutrophils (D-poLNs) the T-cell proliferative responsewas reduced compared to ND-poLNs (p<0.01). Cytokines levels were measured in these culturesupernatants and higher levels of IL-17 were found in D-poLNs respect to ND-poLNs(p<0.01).Besides, we observed that in presence of neutrophils, T-cells from immunized mice 24 hafter footpad injectionupregulateCD25 and CD69 molecules(p<0.01).These resultssuggestthatneutrophil recruitmentindraining popliteal lymph nodes could be modulating the T cell response.