98. NEUTROPHILS RECRUITMENT MODULATES T CELL RESPONSE IN LYMPH NODES

SOFÍA CASTELL; FLORENCIA HARMAN; CAROLINA GORLINO; G MORON; BELKYS A. MALETTO; MARÍA C PISTORESI- PALENCIA.

Buenos Aires

Congreso; 2nd French-Argentine Immunology Congress y LXIII Reunión de la Sociedad Argentina de Inmunología.; 2015

Sociedad Argentina de Inmunología

Previously we demonstrated that when mice were immunized with OVA emulsified in Freund?s complete adjuvant on day 0, boosted with OVA emulsified in Freund?s incomplete adjuvant on day 15, and 10 days after injected with OVA-FITC in the footpad, the main OVA-FITC+ cells recruited in draining popliteal lymph nodes (D-poLNs) were neutrophils whereas these cells were undetectable on control popliteal lymph nodes (ND-poLNs) corresponding to the footpad injected with saline solution (D-poLNs 9,9±2% vs. ND-poLNs 0,3±0,1%; p<0.001). This influx was dependent on an antigen-specific response, since the formation of OVA/anti-OVA immunocomplex (IC) is required. In the present study we evaluate the influence of the presence of neutrophils activated with IC on T-cell response. In order to perform in vitro proliferation assays, CD4+ T-cells purified from OTII mice were co-cultured with cells from D and ND-poLNs obtained from immunized mice 6 h after footpad injection. These cells were stimulated with OVA for 72 h and proliferation was determined by CFSE dilution. We observed that in the presence of neutrophils (D-poLNs) the T-cell proliferative response was reduced compared to ND-poLNs (p<0.01). Cytokines levels were measured in these culture supernatants 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 h after footpad injection upregulate CD25 and CD69 molecules (p<0.01). These results suggest that neutrophil recruitment in draining popliteal lymph nodes could be modulating the T cell response.