A novel block to mouse mammary tumor virus infection of lymphocytes in B10.BR mice

Department of Microbiology and Abramson Family Cancer Center, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.
Journal of Virology (Impact Factor: 4.44). 03/2008; 82(3):1314-22. DOI: 10.1128/JVI.01848-07
Source: PubMed


Classic studies on C57BL-derived mouse strains showed that they were resistant to mouse mammary tumor virus (MMTV) infection.
Although one form of resistance mapped to the major histocompatibility complex (MHC) locus, at least one other, unknown gene
was implicated in this resistance. We show here that B10.BR mice, which are derived from C57BL mice but have the same MHC
locus (H-2k) as susceptible C3H/HeN mice, are resistant to MMTV, and show a lack of virus spread in their lymphoid compartments but not
their mammary epithelial cells. Although in vivo virus superantigen (Sag)-mediated activation of T cells was similar in C3H/HeN
and B10.BR mice, T cell-dependent B-cell and dendritic cell activation was diminished in the latter. Ex vivo, B10.BR T cells
showed a diminished capacity to proliferate in response to the MMTV Sag. The genetic segregation of the resistance phenotype
indicated that it maps to a single allele. These data highlight the role of Sag-dependent T-cell responses in MMTV infection
and point to a novel mechanism for the resistance of mice to retroviral infection that could lead to a better understanding
of the interplay between hosts and pathogens.

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