Infection of human CD4+ rabbit cells with HIV-1: the possibility of the rabbit as a model for HIV-1 infection.
Although human T cell surface glycoprotein CD4 is the cellular receptor for human immunodeficiency virus 1 (HIV-1), the introduction of the human CD4 gene into murine cells does not render them susceptible to HIV-1 infection. Here we have established rabbit transfectant cell lines expressing human CD4 on the cell surface and demonstrated that the CD4+ rabbit transfectants could be readily infected by HIV-1 by co-cultivating with a HIV-1-infected human MOLT-4 T cell line (MOLT-4/HIV). Avid syncytia formation was observed upon co-cultivation and the syncytia abundantly produced HIV-1 mature particles, as revealed by electron microscopy. A significant increase of HIV-1 p24 antigen was also detected in the culture supernatant. The syncytia formation was blocked by pretreating the transfectant with anti-human CD4 or by pretreating the MOLT-4/HIV with anti-HIV-1 serum obtained from an infected individual, indicating that the syncytia formed as a result of the interaction of human CD4 on the rabbit transfectant with the HIV-1 envelope protein expressed on MOLT-4/HIV. In contrast, only a very small proportion of the rabbit transfectants expressed HIV-1-specific antigens upon infection with an HIV-1 stock. This may indicate that, although rabbit cells have partially acquired susceptibility to HIV-1 by transfection of human CD4 gene, rabbit cells may further require such a molecule as might be provided by MOLT-4 to become fully susceptible to HIV-1 infection. The possibility of the rabbit as a model for HIV-1 infection is also discussed.
Yamamura
Y
Y
Department of Immunology, Tokyo Metropolitan Institute of Medical Science, Japan.
Kotani
M
M
Chowdhury
M I
MI
Yamamoto
N
N
Yamaguchi
K
K
Karasuyama
H
H
Katsura
Y
Y
Miyasaka
M
M
D000818:Animals; D015704:CD4 Antigens / Q000235:genetics; D002461:Cell Line, Transformed; D004195:Disease Models, Animal; D016655:HIV Core Protein p24; D015658:HIV Infections / Q000209:etiology*; D015497:HIV-1 / Q000276:immunology; D006801:Humans; D008854:Microscopy, Electron; D011817:Rabbits; D014162:Transfection
D015704:CD4 Antigens; D016655:HIV Core Protein p24