Thein, T. L. | bioRxiv Science

bioRxiv2025

Dengue infection elicits skin tissue-resident and circulating CD8+ T-cells associated with protection from hospitalization.

Dengue is spreading globally and there is urgent need to define immune correlates of protection against this disease. Immune responses against dengue viruses have been studied in blood samples of dengue patients. However, dengue virus infection first occurs in the skin following the bite of an infected Aedes mosquito, and immune responses are initiated within this site. In this study, we investigated the phenotypic, functional and transcriptional profiles of skin and blood T-cell responses and their role in immunity in 73 dengue patients and 10 healthy volunteers. We show that the skin T-cell compartment undergoes dramatic reshaping compared to the blood of dengue patients. CD4+ and CD8+ T-cell responses were highly enriched in the skin compared to the blood of the same patients, and skin-based T-cells expressed markers associated with tissue-resident T (TRM) cells. While the magnitude of the CD4+ T-cell response in the skin was independent to that in the blood, CD8+ T-cell responses in skin and blood were positively correlated. Activated CD8+ T-cells in the skin expressed a core transcriptional signature of TRM cells, further supporting their differentiation to the TRM lineage during infection. The magnitude of both skin and blood CD8+ T-cell responses was associated with protection from hospitalization in this cohort. These data collectively support a protective role of skin-resident and circulating CD8+ T-cells in dengue and provide insights into the biology of TRM cells in human infection. Our findings warrant evaluation of vaccination strategies that induce TRM cells in the skin to enhance protection against dengue. One Sentence SummaryDengue infection elicits skin tissue-resident and circulating CD8+ T-cells associated with protection from hospitalization in adult dengue patients.

immunology↗

bioRxiv2025

N153-linked glycans on envelope protein protect orthoflaviviruses from antibody-mediated clearance

The envelope (E) protein of dengue virus (DENV) is glycosylated at two highly conserved asparagine (N) sites (N67 and N153). The role and importance of these N-linked glycans in DENV pathogenesis has been elusive. Here, we report the critical role of N153-linked glycans on E protein in preventing antibody-mediated viral clearance. A DENV2 mutant lacking N153-linked glycans (N153Q mutant) was engineered and found to be mildly impaired in vitro but drastically attenuated in a symptomatic mouse model of severe dengue, as evidenced by accelerated viral clearance. In B cell-deficient mouse models, N153Q mutant displayed parental virulence and viremia profile. Homologous and heterologous passive transfers of purified IgM from infected B cell-proficient mice into B cell-deficient mice demonstrated the role of N153Q-specific IgM in N153Q attenuation and accelerated clearance, while WT DENV was unaffected by IgM from both WT- and N153Q-infected mice. Furthermore, in vitro neutralization assay supported that the accelerated clearance of N153Q mutant in mice was mediated by non-neutralizing IgM. Furthermore, using plasma samples from convalescent dengue patients and monoclonal antibodies, in vitro neutralization assays showed that N153Q virus was more susceptible than WT to IgG-mediated neutralization. Glycoproteomics combined with molecular dynamics (MD) simulations revealed that glycan composition on E protein influenced IgG binding. Our findings were extended to all DENV serotypes and ZIKV, hence supporting that the N153 glycans-mediated immune evasion strategy is conserved across orthoflaviviruses.

microbiology↗