Vβ14 + T Cells Mediate the Vaccine-Enhanced Disease Induced by Immunization with Respiratory Syncytial Virus (RSV) G Glycoprotein but Not with Formalin-Inactivated RSV

Abstract

ABSTRACT Mice immunized with respiratory syncytial virus (RSV) G glycoprotein or with formalin-inactivated RSV (FI-RSV) exhibit severe disease following RSV challenge. This results in type 2 cytokine production and pulmonary eosinophilia, both hallmarks of vaccine-enhanced disease. RSV G-induced T-cell responses were shown to be restricted to CD4 + T cells expressing Vβ14 in the T-cell receptor (TCR), and the deletion of these T cells resulted in less severe disease. We therefore examined the role of Vβ14 + T cells in FI-RSV-induced disease. BALB/c mice were immunized with vaccinia virus expressing secreted RSV G (vvGs) or with FI-RSV. At the time of challenge with live RSV, mice were injected with antibody to the Vβ14 component of the TCR. vvGs-immunized mice treated with anti-Vβ14 had reduced cytokine levels in the lung. Eosinophil recruitment to the lung was also significantly reduced. In contrast, depletion of Vβ14 + T cells in FI-RSV-immunized mice had little impact on cytokine production or pulmonary eosinophilia. An analysis of TCR Vβ chain usage confirmed a bias toward Vβ14 expression on CD4 + T cells from vvGs-immunized mice, whereas the CD4 + T cells in FI-RSV-immunized mice expressed a diverse array of Vβ chains. These data show that although FI-RSV and vvGs induce responses resulting in similar immunopathology, the T-cell repertoire mediating the response is different for each immunogen and suggest that the immune responses elicited by RSV G are not the basis for FI-RSV vaccine-enhanced disease.