All animals, including humans, show differential susceptibility to infection with viruses. Study of the genetics of susceptibility or resistance to specific pathogens is most easily studied in mice. We have been using mouse mammary tumor virus (MMTV), a retrovirus that causes mammary tumors in mice, to study virus/host interactions. These studies have focused on understanding the mechanisms which determine genetic susceptibility to MMTV infection in vivo, using different inbred, transgenic and knockout mice. This approach has led to identification of many of the steps that MMTV uses in vivo to take advantage of its host, as well an understanding of the genetics of host resistance to virus infection. In the next funding period, we will continue to use genetic approaches to study genes that affect the interaction of MMTV with lymphocytes. In the first Aim, we will study the role of a family of receptors involved in innate immunity, the toll-like receptors (TLR), that we have recently shown are involved in an early step in the MMTV infection pathway, stimulation of B cells. In this aim, we use mice with naturally occurring or targeted mutations in the TLR2, TLR4, RP105 and myd88 genes to determine how signaling through TLR molecules is important for MMTV infection. In the second Aim, we will continue our functional studies on an as of yet unidentified locus in B10.BR mice that confers resistance to MMTV infection at a later step, probably at the level of virus spread in lymphocytes. We will determine what step in the infection pathway is affected in these mice. The results obtained from these studies will greatly increase our understanding of the genetic mechanisms which viruses use to infect their hosts and how genetic resistance to such viruses in the hosts occurs.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA045954-23
Application #
7025767
Study Section
Mammalian Genetics Study Section (MGN)
Program Officer
Cole, John S
Project Start
1987-05-15
Project End
2007-02-28
Budget Start
2006-03-01
Budget End
2007-02-28
Support Year
23
Fiscal Year
2006
Total Cost
$328,458
Indirect Cost
Name
University of Pennsylvania
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Okeoma, Chioma M; Shen, Ming; Ross, Susan R (2008) A novel block to mouse mammary tumor virus infection of lymphocytes in B10.BR mice. J Virol 82:1314-22
Courreges, Maria Cecilia; Burzyn, Dalia; Nepomnaschy, Irene et al. (2007) Critical role of dendritic cells in mouse mammary tumor virus in vivo infection. J Virol 81:3769-77
Burzyn, Dalia; Rassa, John C; Kim, David et al. (2004) Toll-like receptor 4-dependent activation of dendritic cells by a retrovirus. J Virol 78:576-84
Rassa, John C; Ross, Susan R (2003) Viruses and Toll-like receptors. Microbes Infect 5:961-8
Czarneski, Jennifer; Rassa, John C; Ross, Susan R (2003) Mouse mammary tumor virus and the immune system. Immunol Res 27:469-80
Lee, James C; Kim, David C; Gee, Michael S et al. (2002) Interleukin-12 inhibits angiogenesis and growth of transplanted but not in situ mouse mammary tumor virus-induced mammary carcinomas. Cancer Res 62:747-55
Rassa, John C; Meyers, Jennifer L; Zhang, Yuanming et al. (2002) Murine retroviruses activate B cells via interaction with toll-like receptor 4. Proc Natl Acad Sci U S A 99:2281-6
Czarneski, Jennifer; Berguer, Paula; Bekinschtein, Pedro et al. (2002) Neonatal infection with a milk-borne virus is independent of beta7 integrin- and L-selectin-expressing lymphocytes. Eur J Immunol 32:945-56
Czarneski, J; Meyers, J; Peng, T et al. (2001) Interleukin-4 up-regulates mouse mammary tumor virus expression yet is not required for in vivo virus spread. J Virol 75:11886-90
Hook, L M; Agafonova, Y; Ross, S R et al. (2000) Genetics of mouse mammary tumor virus-induced mammary tumors: linkage of tumor induction to the gag gene. J Virol 74:8876-83

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