A PEPTIDE DERIVED FROM THE G GLYCOPROTEIN OF THE RESPIRATORY SYNCYTIAL VIRUS DECREASES NEUTROPHIL FUNCTIONALITY

BIRNBERG WEISS F; GUTMAN, J; CASTRO, J; PITTALUGA VILLARREAL JR; ESPERANTE S; LANDONI V.I; ALVAREZ-PAGGI D; FERNÁNDEZ GC

San Luis

Congreso; LXXI REUNIÓN CIENTÍFICA ANUAL DE LA SOCIEDAD ARGENTINA DE INMUNOLOGÍA (SAI); 2023

SAI

Respiratory syncytial virus (RSV) is by far the most frequent cause of bronchiolitis and viral pneumonia in infants and young children worldwide. Two surface RSV glycoproteins, F and G, are key to the biology of infection. Although G has been studied mostly as a possible vaccine candidate against RSV, less is known about its immune modulatory properties, partly ascribed to complex formation with CX3C.R1. Neutrophils (PMN) are highly recruited to the lungs during RSV infection. Moreover, it has been reported that some of the antimicrobial mechanisms of PMN show anti-viral properties. Therefore, our objective was to assess if a peptide corresponding to the receptor-binding site derived from G was able to modulate PMN functional responses. We used purified PMN from healthy donors and measured by flow cytometry their activation (CD11b up-regulation or reactive oxygen species (ROS) generation) after incubation for 30 min with the G peptide (1 μM) alone or together with an activating stimulus (LPS 0.5 ng/ml for CD11b measurement or fMLP 10-7 M for ROS generation). We found that the G peptide by itself decreased CD11b expression and completely abolished up-regulation of CD11b caused by LPS (MFI±SEM of CD11b: Basal: 323±37; G: 189±26*; LPS: 455±42*; LPS+G: 208±23*#, *p