Circulating rotavirus-specific T cells have a poor functional profile

- The quality and magnitude of circulating RV-T cell responses are relatively poor.
- Circulating RV-CD4 T cells are enriched in monofunctional IFN-γ+ cells.
- Treatment with rIL-2 increased the frequencies of cytokine secreting RV-T cells.

Frequencies of circulating T cells producing IFN-γ, TNF-α, and IL-2, and percentages of T cells proliferating after stimulation with rotavirus (RV), tetanus toxoid, and influenza were evaluated in PBMC derived from healthy adults and children. In addition, the potential anergic state of RV-specific T cells was analyzed by stimulation of PBMC with RV antigen in the presence of three anergy inhibitors (rIL-2, rIL-12, or DGKα-i). The quality and magnitude of RV-T cell responses were significantly lower than those of tetanus toxoid and influenza antigens. RV-CD4 T cell response was enriched in monofunctional IFN-γ+ cells, while influenza-CD4 and tetanus toxoid-CD4 T cell responses were enriched in multifunctional T cells. Moreover, rIL-2 - unlike rIL-12 or DGKα-i - increased the frequencies of RV-CD4 TNF-α+, CD4 IFN-γ+, and CD8 IFN-γ+ cells. Thus, circulating RV-T cells seem to have a relatively poor functional profile that may be partially reversed in vitro by the addition of rIL-2.