Pre-existing T cell memory against zika virus

Blake Schouest, Alba Grifoni, John Pham, Jose Mateus, John Sydney, James D. Brien, Aruna D. de Silva, Angel Balmaseda, Eva Harris, Alessandro Sette, Daniela Weiskopf

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


The mosquito-borne Zika virus (ZIKV) has spread rapidly into regions where dengue virus (DENV) is endemic, and flavivirus cross-reactive T cell responses have been observed repeatedly in animal models and in humans. Preexisting cellular immunity to DENV is thought to contribute to protection in subsequent ZIKV infection, but the epitope targets of cross-reactive T cell responses have not been comprehensively identified. Using human blood samples from the regions of Nicaragua and Sri Lanka where DENV is endemic that were collected before the global spread of ZIKV in 2016, we employed an in vitro expansion strategy to map ZIKV T cell epitopes in ZIKV-unexposed, DENV-seropositive donors. We identified 93 epitopes across the ZIKV proteome, and we observed patterns of immunodominance that were dependent on antigen size and sequence identity to DENV. We confirmed the immunogenicity of these epitopes through a computational HLA binding analysis, and we showed that cross-reactive T cells specifically recognize ZIKV peptides homologous to DENV sequences. We also found that these CD4 responses were derived from the memory T cell compartment. These data have implications for understanding the dynamics of flavivirus-specific T cell immunity in areas of endemicity. IMPORTANCE Multiple flaviviruses, including Zika virus (ZIKV) and the four serotypes of dengue virus (DENV), are prevalent in the same large tropical and equatorial areas, which are inhabited by hundreds of millions of people. The interplay of DENV and ZIKV infection is especially relevant, as these two viruses are endemic in largely overlapping regions, have significant sequence similarity, and share the same arthropod vector. Here, we define the targets of preexisting immunity to ZIKV in unexposed subjects in areas where dengue is endemic. We demonstrate that preexisting immunity to DENV could shape ZIKV-specific responses, and DENV-ZIKV cross-reactive T cell populations can be expanded by stimulation with ZIKV peptides. The issue of potential ZIKV and DENV cross-reactivity is of relevance for understanding patterns of natural immunity, as well as for the development of diagnostic tests and vaccines.

Original languageEnglish
Article numbere00132
JournalJournal of Virology
Issue number12
StatePublished - Jun 2021

Bibliographical note

Publisher Copyright:
Copyright © 2021 Schouest et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license.


  • Cross-reactivity
  • Dengue virus
  • Preexisting memory
  • T cells
  • Zika virus

ASJC Scopus subject areas

  • Microbiology
  • Immunology
  • Insect Science
  • Virology


Dive into the research topics of 'Pre-existing T cell memory against zika virus'. Together they form a unique fingerprint.

Cite this