LAP Cells Modulate Protection Induced by Oral Vaccination with Rhesus Rotavirus in a Neonatal Mouse Model.

Transforming growth factor β (TGF-β) has been shown to play a role in immunity against different pathogens and against parasites However, its role in viral infections is incompletely understood. Using a neonatal mouse model of heterologous rhesus rotavirus (RV) vaccination, we show that the vaccine induced rotavirus-specific CD4 T cells, the majority of which lacked expression of KLRG1 or CD127, and a few regulatory rotavirus-specific CD4 T cells that expressed surface latency-associated peptide (LAP)-TGF-β. In these mice, inhibiting TGF-β, with both a neutralizing antibody and an inhibitor of TGF-β receptor signaling (activin receptor-like kinase 5 inhibitor [ALK5i]), did not change the development or intensity of the mild diarrhea induced by the vaccine, the rotavirus-specific T cell response, or protection against a subsequent challenge with a murine EC-rotavirus.