Immunology and Immunopathology of the Intestines: Reoviruses as Probes of the Gut Mucosal T Cell Population

Abstract

Reovirus, serotype 1, causes a transient, asymptomatic infection of the murine intestine when given intraduodenally or orally. However, this infection markedly perturbs both B-and T-cell populations in Peyer's patches (PP) resulting in: 1) a rapid and persistent increase in specific precursors for cytotoxic T cells (pCTL) and a gradient of frequencies highest in PP and lowest in distal lymphoid tissue; 2) a similar increase in memory B cells committed to IgA; 3) the transient appearance of a subset of germinal center B cells identified by MAb, GC-T; A) the appearance of pCTL among intraepithelial lymphocytes; and 5) the antigen nonspecific alteration in Ig isotype potential of B cells previously primed and found in PP. The pCTL appearing upon acute gut mucosal infection with reovirus are Thy1⁺, Lyt2⁺, virus-specific, viral serotype non-specific, class I MHC haplotype restricted and occur within the subset of T cells which newly appears also identified by MAb GC-T. Infections of both neonatal and severe-combined immunodeficient mice indicate that the elements of the immune system may operate at many levels to resist, limit, contain, and resolve viral infection.