NEUTROPHILS CAN REGULATE SPECIFIC T CELL RESPONSE IN LYMPH NODES

MALETTO B; BRAILOVSKY V; ALIGNANI D,; LISCOVSKY M,; RÓPOLO A; MORON G; PISTORESI MC

Cordoba, Argentina

Congreso; VII Congreso Latinoamericano de Inmunologia; 2005

Asociacion Latinoamericana de Inmunologia

We have shown that OVA/CFAimmunized mice injected with FITC-labeled-OVA in footpads had an influx of OVAFITC+ neutrophils in draining lymph nodes (LN). This neutrophils influx was rapid (peaking 6 hours after OVA injection) and was resolved at 72 hours. This neutrophil influx only occurred in presence of OVA specific antibodies. In addition, OVAFITC+ neutrophils present in LN displayed high levels of intracellular TNFá. To investigate whether neutrophils contribute to OVA T cell response, we injected OVA (day 0) in footpads in two groups of OVA/CFAimmunized mice: (I) treated with antibody RB6.8C5 on days 2, 1, 0, +1, +2 (mice depleted of neutrophils) and (II) treated with isotype control antibody. On days 0 and +3 (day of the sacrifice of the animals) neutrophils (Gr1high CD11bhigh) were absent in blood and LN from group I. In LN cells from neutrophil depleted mice, higher levels of IL5 were observed (pg/ml: 1140±248 vs 242±39, p<0,005); while the levels of INFã were similar (pg/ml: 3401±1161 vs 2825±892). In conclusion, removal of neutrophils modified the cytokines balance in OVA specific T cell response. These data identify a role for neutrophils in the adaptative immune response to immune complexes.á. To investigate whether neutrophils contribute to OVA T cell response, we injected OVA (day 0) in footpads in two groups of OVA/CFAimmunized mice: (I) treated with antibody RB6.8C5 on days 2, 1, 0, +1, +2 (mice depleted of neutrophils) and (II) treated with isotype control antibody. On days 0 and +3 (day of the sacrifice of the animals) neutrophils (Gr1high CD11bhigh) were absent in blood and LN from group I. In LN cells from neutrophil depleted mice, higher levels of IL5 were observed (pg/ml: 1140±248 vs 242±39, p<0,005); while the levels of INFã were similar (pg/ml: 3401±1161 vs 2825±892). In conclusion, removal of neutrophils modified the cytokines balance in OVA specific T cell response. These data identify a role for neutrophils in the adaptative immune response to immune complexes.