Limited IL-2 bioavailability during pediatric RSV infection

ERRA DIAZ, FERNANDO; HOLGADO, PÍA; SANANEZ, INÉS; DE LILLO, LEONARDO; GEFFNER, JORGE; RAIDEN, SILVINA; MENEGALI, CECILIA; ARRUVITO, LOURDES

Ciudad Autónoma de Buenos Aires

Congreso; Reunión Conjunta de Sociedades de Biociencias; 2017

LIMITED IL-2 BIOAVAILABILITY DURING PEDIATRIC RSV INFECTIONIt is well known that Respiratory Syncytial Virus, despite having slight antigenic variation, repeatedly infects throughout life reflecting a defect in the development of immunological memory. In addition, we have reported that severe RSV infection of infants induced a dramatic reduction in the frequency of peripheral blood regulatory T cells (Tregs). Because IL-2 is crucial for both, the development of T cell memory and the maintenance of Tregs, we analyzed whether the production and/or the availability of IL-2 was affected in RSV-infected children (RSV-ch). Here, we aimed 1) to analyze if IL-2 addition increased the expression of FOXP3 in CD4+ T cells from RSV-ch; 2) to determine the ability of CD4+ T cells from RSV-ch to produce IL-2 upon in vitro stimulation; 3) to analyze the serum levels of soluble IL-2Rα (sCD25); and 4) to explore the response of CD4+ T cells from RSV-ch to sCD25. We observed that incubation of CD4+ T cells from RSV-ch with IL-2 (20 ng/ml) markedly increased the frequency of CD4+FOXP3+ T cells (p