Related Experiment Videos
Rabbit cells expressing human CD4 and human CCR5 are highly permissive for human immunodeficiency virus type 1
R F Speck1, M L Penn, J Wimmer
1Gladstone Institute of Virology and Immunology, University of California, San Francisco, California 94141-9100, USA.
Abstract:
To evaluate the feasibility of using transgenic rabbits expressing CCR5 and CD4 as a small-animal model of human immunodeficiency virus type 1 (HIV) disease, we examined whether the expression of the human chemokine receptor (CCR5) and human CD4 would render a rabbit cell line (SIRC) permissive to HIV replication. Histologically, SIRC cells expressing CD4 and CCR5 formed multinucleated cells (syncytia) upon exposure to BaL, a macrophagetropic strain of HIV that uses CCR5 for cell entry. Intracellular viral capsid p24 staining showed abundant viral gene expression in BaL-infected SIRC cells expressing CD4 and CCR5. In contrast, neither SIRC cells expressing CD4 alone nor murine 3T3 cells expressing CCR5 and CD4 exhibited significant expression of p24. These stably transfected rabbit cells were also highly permissive for the production of virions upon infection by two other CCR5-dependent strains (JR-CSF and YU-2) but not by a CXCR4-dependent strain (NL4-3). The functional integrity of these virions was demonstrated by the successful infection of human peripheral blood mononuclear cells (PBMC) with viral stocks prepared from these transfected rabbit cells. Furthermore, primary rabbit PBMC were found to be permissive for production of infectious virions after circumventing the cellular entry step. These results suggest that a transgenic rabbit model for the study of HIV disease may be feasible.
Insights
Transgenic rabbits expressing CCR5 and CD4 support HIV replication, forming syncytia and producing infectious virions. This suggests a potential new small-animal model for studying human immunodeficiency virus (HIV) disease.
Area of Science:
- Virology
- Immunology
- Genetics
Background:
- Human immunodeficiency virus (HIV) infection remains a global health challenge.
- Small-animal models are crucial for understanding HIV pathogenesis and developing therapies.
- Current models have limitations in fully recapitulating human disease.
Purpose of the Study:
- To assess the feasibility of using transgenic rabbits expressing human CD4 and CCR5 as an HIV-1 infection model.
- To determine if rabbit cells engineered to express HIV receptors are permissive to viral replication.
Main Methods:
- Transfection of rabbit SIRC cells with human CD4 and CCR5 genes.
- Infection of engineered cells with various HIV-1 strains (macrophage-tropic and T-cell-tropic).
- Analysis of viral replication through syncytia formation, p24 antigen staining, and virion production.
Main Results:
- SIRC cells expressing CD4 and CCR5 supported HIV-1 replication, showing syncytia formation and abundant p24 expression upon infection with CCR5-dependent strains.
- Engineered rabbit cells produced infectious virions capable of infecting human peripheral blood mononuclear cells (PBMC).
- Primary rabbit PBMC also showed permissiveness to viral production.
Conclusions:
- Transgenic rabbits expressing CCR5 and CD4 can serve as a viable small-animal model for HIV-1 research.
- This model facilitates the study of HIV entry, replication, and pathogenesis.
- Further development could lead to novel therapeutic strategies for HIV disease.