title: Protection from secondary dengue virus infection in a mouse model reveals the role of serotype cross-reactive B and T cells.
abstract: The four dengue virus (DENV) serotypes cause dengue fever and dengue hemorrhagic fever/dengue shock syndrome. Although severe disease has been associated with heterotypic secondary DENV infection, most secondary DENV infections are asymptomatic or result in classic DF. The role of cross-reactive immunity in mediating cross-protection against secondary heterotypic DENV infection is not well understood. DENV infection of IFN-α/β and IFN-γ receptor-deficient (AG129) mice reproduces key features of human disease. We previously demonstrated a role in cross-protection for pre-existing cross-reactive Abs, maintained by long-lived plasma cells. In this study, we use a sequential infection model, infecting AG129 mice with DENV-1, followed by DENV-2 6-8 wk later. We find that increased DENV-specific avidity during acute secondary heterotypic infection is mediated by cross-reactive memory B cells, as evidenced by increased numbers of DENV-1-specific cells by ELISPOT and higher avidity against DENV-1 of supernatants from polyclonally stimulated splenocytes isolated from mice experiencing secondary DENV-2 infection. However, increased DENV-specific avidity is not associated with increased DENV-specific neutralization, which appears to be mediated by naive B cells. Adoptive transfer of DENV-1-immune B and T cells into naive mice prior to secondary DENV-2 infection delayed mortality. Mice depleted of T cells developed signs of disease, but recovered after secondary DENV infection. Overall, we found that protective cross-reactive Abs are secreted by both long-lived plasma cells and memory B cells and that both cross-reactive B cells and T cells provide protection against a secondary heterotypic DENV infection. Understanding the protective immunity that develops naturally against DENV infection may help design future vaccines.
authors: School of Public Health, University of California, Berkeley, CA 94720-7354, USA. simona.zompi@gmail.com
authors: Simona
authors: S
authors: Zompi
authors: Brian H
authors: BH
authors: Santich
authors: P Robert
authors: PR
authors: Beatty
authors: Eva
authors: E
authors: Harris
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000276:immunology*; D002460:Cell Line; D003429:Cross Reactions / Q000276:immunology; D003716:Dengue Virus / Q000276:immunology*; D004195:Disease Models, Animal; D006801:Humans; D007156:Immunologic Memory; D007372:Interferons / Q000276:immunology; D051379:Mice; D008817:Mice, Mutant Strains; D010950:Plasma Cells / Q000276:immunology* / Q000473:pathology / Q000821:virology; D019595:Severe Dengue / Q000276:immunology* / Q000473:pathology; D013601:T-Lymphocytes / Q000276:immunology* / Q000473:pathology / Q000821:virology
chemical_list: D000956:Antigens, Viral; D007372:Interferons