Establishment of murine gammaherpesvirus latency in B cells is not a stochastic event

PLoS Pathog. 2014 Jul 31;10(7):e1004269. doi: 10.1371/journal.ppat.1004269. eCollection 2014 Jul.

Abstract

Murid γ-herpesvirus-4 (MuHV-4) promotes polyclonal B cell activation and establishes latency in memory B cells via unclear mechanisms. We aimed at exploring whether B cell receptor specificity plays a role in B cell susceptibility to viral latency and how this is related to B cell activation. We first observed that MuHV-4-specific B cells represent a minority of the latent population, and to better understand the influence of the virus on non-MuHV-4 specific B cells we used the SWHEL mouse model, which produce hen egg lysozyme (HEL)-specific B cells. By tracking HEL+ and HEL- B cells, we showed that in vivo latency was restricted to HEL- B cells while the two populations were equally sensitive to the virus in vitro. Moreover, MuHV-4 induced two waves of B cell activation. While the first wave was characterized by a general B cell activation, as shown by HEL+ and HEL- B cells expansion and upregulation of CD69 expression, the second wave was restricted to the HEL- population, which acquired germinal center (GC) and plasma cell phenotypes. Antigenic stimulation of HEL+ B cells led to the development of HEL+ GC B cells where latent infection remained undetectable, indicating that MuHV-4 does not benefit from acute B cell responses to establish latency in non-virus specific B cells but relies on other mechanisms of the humoral response. These data support a model in which the establishment of latency in B cells by γ-herpesviruses is not stochastic in terms of BCR specificity and is tightly linked to the formation of GCs.

MeSH terms

  • Animals
  • B-Lymphocytes / immunology*
  • Flow Cytometry
  • Fluorescent Antibody Technique
  • Herpesviridae Infections / immunology*
  • Herpesviridae Infections / virology
  • Immunity, Cellular
  • Immunization
  • Lymphocyte Activation
  • Mice
  • Mice, Inbred C57BL
  • Muramidase / immunology*
  • Rhadinovirus / pathogenicity
  • Tumor Virus Infections / immunology*
  • Tumor Virus Infections / virology
  • Virus Latency / immunology*

Substances

  • hen egg lysozyme
  • Muramidase

Grants and funding

Research in JPS's lab was supported by a grant from the Portuguese Fundação para a Ciência e Tecnologia (FCT) (PTDC/SAU-MII/099314/2008). JD was recipient of a FCT fellowship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.