MHC Class II Hierarchy of Superantigen Presentation Predicts Efficiency of Infection With Mouse Mammary Tumor Virus

Int Immunol. 1994 Sep;6(9):1403-7. doi: 10.1093/intimm/6.9.1403.


Superantigens (SAgs) encoded by infectious mouse mammary tumor viruses (MMTVs) play a crucial role in the viral life cycle. Their expression by infected B cells induces a proliferative immune response by SAg-reactive T cells which amplifies MMTV infection. This response most likely ensures stable MMTV infection and transmission to the mammary gland. Since T cell reactivity to SAgs from endogenous Mtv loci depends on MHC class II molecules expressed by B cells, we have determined the ability of MMTV to infect various MHC congenic mice. We show that MHC class II I-E+ compared with I-E- mouse strains show higher levels of MMTV infection, most likely due to their ability to induce a vigorous SAg-dependent immune response following MMTV encounter. Inefficient infection is observed in MHC class II I-E- mice, which have been shown to present endogenous SAgs poorly. Therefore, during MMTV infection the differential ability of MHC class II molecules to form a functional complex with SAg determines the magnitude of the proliferative response of SAg-reactive T cells. This in turn influences the degree of T cell help provided to infected B cells and therefore the efficiency of amplification of MMTV infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigen Presentation / immunology*
  • B-Lymphocytes / immunology
  • DNA, Viral / analysis
  • Female
  • Flow Cytometry
  • Histocompatibility Antigens Class II / immunology*
  • Major Histocompatibility Complex / immunology*
  • Male
  • Mammary Tumor Virus, Mouse / genetics
  • Mammary Tumor Virus, Mouse / immunology
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Mice, Mutant Strains
  • Mice, Transgenic
  • Polymerase Chain Reaction
  • Retroviridae Infections / immunology*
  • Superantigens / immunology*
  • T-Lymphocytes / immunology
  • Tumor Virus Infections / immunology*


  • DNA, Viral
  • Histocompatibility Antigens Class II
  • Superantigens