Association of dengue virus‐specific polyfunctional T‐cell responses with clinical disease severity in acute dengue infection

Abstract

Introduction Although the role of dengue virus (DENV)‐specific T cells in the pathogenesis of acute dengue infection is emerging, the functionality of virus‐specific T cells associated with milder clinical disease has not been well studied. We sought to investigate how the functionality of DENV–NS3 and DENV–NS5 protein‐specific T cells differ in patients with dengue fever (DF) and dengue hemorrhagic fever (DHF). Methods Using intracellular cytokine assays, we assessed the production of interferon γ (IFNγ), tumor necrosis factor‐α (TNF‐α), macrophage inflammatory protein‐1β (MIP‐1β), and CD107a expression in adult patients with acute DF (n = 21) and DHF (n = 22). Results Quadruple cytokine‐producing, polyfunctional DENV–NS3‐ and DENV–NS5‐specific T cells were more frequent in those with DF when compared to those with DHF. While DENV–NS3‐ and DENV–NS5‐specific T cells in patients with DF expressed IFNγ > TNF‐α > MIP‐β > CD107a, T cells of those with DHF predominantly expressed CD107a > MIP‐1β > IFNγ > TNF‐α. Overall production of IFNγ or TNF‐α by DENV–NS3‐ and DENV–NS5‐specific T cells was significantly higher in patients with DF. The majority of NS3‐specific T cells in patients with DF (78.6%) and DHF (68.9%) were single‐cytokine producers; 76.6% of DENV–NS5‐specific T cells in those with DF and 77.1% of those with DHF, produced only a single cytokine. However, no significant association was found with polyfunctional T‐cell responses and the degree of viraemia. Conclusions Our results suggest that the functional phenotype of DENV‐specific T cells are likely to associate with clinical disease severity.

Identification of Immune Responses to Japanese Encephalitis Virus Specific T Cell Epitopes

“…Although recognition of antigens by T cells is HLA-restricted and therefore, responses to these JEV specific peptides would depend on an individual's HLA type, we wished to identify responses that are recognized by a large proportion of JEV immune individuals irrespective of their HLA type. For instance, in acute DENV infection, although recent studies show that DENV-specific T cells are likely to be protective (9,12,15,41), studies have also shown that DENV-specific T cells are highly cross reactive and possibly contribute to disease pathogenesis by producing pro-inflammatory cytokines (29,42). However, identification of JEV-specific T cell epitopes that do not cross react with DENV, would also enable us to better understand T cell immunity to the DENV, in the context of background immunity to the JEV, especially following vaccination.…”

“…Intracellular staining was carried out as previously described (27,33). To determine CD107a expression, PBMCs were stained with anti CD107a-FITC monoclonal antibodies for 30 min at 1-2 × 10 6 /ml in RPMI 1640 plus 10% FCS, prior to stimulation with the antigen (15). PBMCs were stained with anti CD3, anti CD4 and CD8, permeabilized and fixed with Cytofix/Cytoperm (Biolegend, USA) and acquired using a Guava-easy Cyte 12 HT Flowcytometer (Merck, Germany) and analyzed with FCS express 6 Flow Research Edition.…”

“…In our previous studies we showed that T cell responses of 20-30% of individuals who were naturally infected with DENV were cross-reactive with JEV (14). Apart from the magnitude of the T cell response, the functionality of T cell responses, specific to either JEV or DENV, have been shown to associate with the clinical disease outcome in both infections (5,15). Virus-specific T cells of patients who had a milder clinical disease (either JEV or DENV), had different polyfunctional T cell signatures compared to those who had more severe disease (5,12,15).…”

“…Apart from the magnitude of the T cell response, the functionality of T cell responses, specific to either JEV or DENV, have been shown to associate with the clinical disease outcome in both infections (5,15). Virus-specific T cells of patients who had a milder clinical disease (either JEV or DENV), had different polyfunctional T cell signatures compared to those who had more severe disease (5,12,15). Due to the similarity of JEV and DENV, infection or immunization with either virus has a potential to influence both the magnitude and the functionality of T cell responses to each other.…”

Transcriptomic immune profiles of human flavivirus‐specific T‐cell responses

“…On the other hand, many other studies have supported a protective role in the context of DENV infection. Recently, additional studies comparing the acute form of the disease have correlated the early onset of interferon‐ γ (IFN‐ γ )‐producing T cells with a mild form of the DENV disease as well as with increased T‐cell polyfunctionality overall, suggesting that lack of an efficient and rapid T‐cell response might be important for DENV protection and not immunopathogenesis …”