Direct physical interaction involving CD40 ligand on T cells and CD40 on B cells is required to propagate MMTV

Immunity. 1995 Jul;3(1):139-46. doi: 10.1016/1074-7613(95)90166-3.


The propagation of mouse mammary tumor virus (MMTV) has been analyzed in mice defective for expression of CD40 ligand (CD40L). Mice with endogenous viral superantigen (SAG) delete T cells with cognate V beta independent of CD40L expression. Nevertheless, CD40L-mice do not show deletion of cognate T cells after being exposed to infectious MMTV and have greatly diminished viral replication. The response of CD40L- T cells to SAG in vitro is also impaired, but can be reconstituted by adding B cells activated by recombinant CD40L to express costimulatory molecules. Thus, direct CD40L-dependent B cell activation appears to be a critical step in the life cycle of MMTV. The initial step in SAG-dependent T cell activation, and hence the MMTV life cycle, may be mediated by non-B cells, because splenocytes from B cell-deficient SAG-transgenic mice are able to activate cognate T cells.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antigens, CD / physiology*
  • Antigens, Differentiation, B-Lymphocyte / physiology*
  • B-Lymphocytes / physiology
  • B-Lymphocytes / virology*
  • CD40 Antigens
  • CD40 Ligand
  • Cell Communication
  • Lymphocyte Activation
  • Mammary Tumor Virus, Mouse / physiology*
  • Membrane Glycoproteins / physiology*
  • Mice
  • Mice, Knockout
  • T-Lymphocytes / physiology
  • T-Lymphocytes / virology*
  • Virus Replication


  • Antigens, CD
  • Antigens, Differentiation, B-Lymphocyte
  • CD40 Antigens
  • Membrane Glycoproteins
  • CD40 Ligand