T cells producing multiple combinations of IFNγ, TNF and IL10 are associated with mild forms of dengue infection.

Gonçalves Pereira, Marcela Helena; Figueiredo, Maria Marta; Queiroz, Camila Pereira; Magalhães, Télcia Vasconcelos Barros; Mafra, Adriana; Diniz, Lilian Martins Oliveira; da Costa, Último Libânio; Gollob, Kenneth J; do Valle Antonelli, Lis Ribeiro; da Costa Santiago, Helton

Multifunctional IL10+ Th1 cells have been implicated in favorable evolution of many infectious diseases, promoting an efficacious immune response while limiting immunopathology. Here, we investigated the presence of multifunctional CD4+ and CD8+ T cells which expressed IFNγ, IL10 and TNF, or its combinations during dengue infection. Peripheral blood mononuclear cells (PBMC) from outpatients with dengue (mild dengue forms) and hospitalized patients (or patients with dengue with warning signs and severe dengue) were cultured in the presence of envelope (ENV) or NS3 peptide libraries of DENV during critical (hospitalization period) and convalescence phases. The production of IFNγ, IL10 and TNF by CD4+ and CD8+ T cells was assessed by flow cytometry. Our data shows that patients with mild dengue, when compared to patients with dengue with warning signs and severe dengue, presented higher frequencies of multifunctional T cells like NS3-specific IFNγ/IL10-producing CD4+ T cells in critical phase and NS3- and ENV-specific CD8+ T cells producing IFNγ/IL10. In addition, NS3-specific CD8+ T cells producing high levels of IFNγ/TNF and IFNγ/TNF/IL10 were also observed in mild dengue group. We observed that multifunctional T cells produced higher levels of cytokines as measured by intracellular content when compared to single producer T cells. Importantly, multifunctional CD4+ and CD8+ T cells producing IFNγ, TNF and IL10 simultaneously displayed positive correlation with platelet levels suggesting a protective role of this population. The presence of IL10+ Th1 and IL10+ Tc1 multifunctional cells was associated with mild dengue presentation suggesting that these cells play a role in clinical evolution of dengue infection.