U. Beutner et al., B-CELLS ARE ESSENTIAL FOR MURINE MAMMARY-TUMOR VIRUS TRANSMISSION, BUT NOT FOR PRESENTATION OF ENDOGENOUS SUPERANTIGENS, The Journal of experimental medicine, 179(5), 1994, pp. 1457-1466
Murine mammary tumor viruses (MMTVs) are retroviruses that encode supe
rantigens capable of stimulating T cells via superantigen-reactive T c
ell receptor V beta chains. MMTVs are transmitted to the suckling offs
pring through milk. Here we show that B cell-deficient mice foster nur
sed by virus-secreting mice do not transfer infectious MMTVs to their
offspring. No MMTV proviruses could be detected in the spleen and mamm
ary tissue of these mice, and no deletion of MMTV superantigen-reactiv
e T cells occurred. By contrast, T cell deletion and positive selectio
n due to endogenous MMTV superantigens occurred in B cell-deficient mi
ce. We conclude that B cells are essential for the completion of the v
iral life cycle in vivo, but that endogenous MMTV superantigens can be
presented by cell types other than B cells.