CD40‐deficient mice infected with the defective murine leukemia virus LP‐BM5def do not develop murine AIDS but produce IgE and IgG1 in vivo

• Published in: European journal of immunology 1999-02, Vol.29 (2), p.615-625
• Main Authors: Yu, Philipp, Morawetz, Renate A., Chattopadhyay, Sisir, Makino, Masahiko, Kishimoto, Tadamitsu, Kikutani, Hitoshi
• Format: Article
• Language: English
• Subjects: AIDS/HIV; Animals; CD40 Antigens - genetics; CD40 Antigens - immunology; Co‐stimulatory molecule; Immunodeficiency disease; Immunoglobulin E - immunology; Immunoglobulin G - immunology; Isotype switching; Knockout; Leukemia Virus, Murine - immunology; Mice; Mice, Knockout; Murine Acquired Immunodeficiency Syndrome - immunology; Murine leukemia virus; Retroviridae Infections - immunology; Tumor Virus Infections - immunology
• ISSN: 0014-2980; 1521-4141
• DOI: 10.1002/(SICI)1521-4141(199902)29:02<615::AID-IMMU615>3.0.CO;2-I

CD40‐deficient mice, when inoculated with the LP‐BM5def murine retorvirus, become infected and show virus expression similar to wild‐type mice. However, unlike the wild‐type mice, CD40‐deficient mice do not develop symptoms of immunodeficiency, lymphoproliferative disease and the typical histological changes in the lymphoid tissue. These results show that the CD40‐CD40 ligand (CD40L) interaction in vivo is essential for anergy induction and the subsequent development of immunodeficiency and pathologic expansion of lymphocytes. Infected CD40‐deficient mice and their littermates express a similar pattern of cytokine mRNA, which is not biased towards a Th2 phenotype. Nevertheless, hypergammaglobulinemia is induced in infected wild‐type and CD40‐deficient mice. Surprisingly, murine AIDS infection even induces IgE production in CD40‐deficient mice in vivo. Our data demonstrate that antibody class switch to IgE and IgG1 can be induced by a retroviral infection in vivo even in the absence of CD40‐CD40L interaction and an apparent switch to a Th2 cytokine production.