Immunology paper on Alphaherpesvirus-induced activation of plasmacytoid dendritic cells

7 Dec 2021

Alphaherpesvirus-induced activation of plasmacytoid dendritic cells depends on the viral glycoprotein gD and is inhibited by noninfectious light particles

Plasmacytoid dendritic cells (pDC) are the most powerful source of antiviral type I interferon cytokines in the body.


Type I interferons are crucial in the rapid, innate response against virus infections. They are of particular importance during infections with alphaherpesviruses, which is illustrated by the fact that deficient type I interferon responses are associated with aggravated and sometimes life threatening alphaherpesvirus disease, including herpes simplex encephalitis. In this paper, using the porcine alphaherpesvirus pseudorabies virus (PRV), we show that the viral envelope glycoprotein gD, is required for activation of the type I interferon response by pDC.


In addition, using PRV and the human alphaherpesvirus herpes simplex virus 1 (HSV1), we show that so-called virus light-particles (L-particles), which are quite enigmatic non-infectious virus particles that lack a viral genome and that are produced by all alphaherpesviruses studied so far, inhibit this gD-mediated activation of pDC.


Hence, these data identify a novel role for the gD glycoprotein of alphaherpesviruses in triggering the type I interferon response by pDC and reveal that alphaherpesvirus L-particles suppress the type I interferon response by pDC.


Since the type and extent of the innate response affects the development of the adaptive immune response, these data may contribute to the rational design of alphaherpesvirus vaccines that trigger an optimal type I interferon response.