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Updated: Aug 26, 2026
In Vitro Assay to Evaluate the Impact of Immunoregulatory Pathways on HIV-specific CD4 T Cell Effector Function
Published on: October 15, 2013
Inhibition of ShcA isoforms p46/p52Shc enhances HIV-1 replication in CD4+ T-lymphocytes
Luca Benetti1, Arianna Calistri, Cristina Ulivieri
1Department of Histology, Microbiology and Medical Biotechnologies, Section of Microbiology and Virology, University of Padua, Padua, Italy.
Abstract:
HIV-1 infection decreases the number of CD4(+) T-cells, and apoptosis has been suggested among the mechanisms. Proteins of the Shc family are involved in a complex network of signal transduction, differentiation, and apoptotic response to stress in many different cell types. Out of three homologous gene products (ShcA, ShcB, and ShcC), only two splicing variants of ShA are expressed in T-lymphocytes, namely p46Shc and p52Shc. In the present study, we report that inhibition of p46Shc and p52Shc by a dominant negative mutant enhances the yield of HIV-1 particles production without affecting efficiency of viral gene expression in CD4(+)-infected cells. The increase in HIV-1 replication in cells expressing the dominant negative mutant isoform ultimately correlates with a decrease in the percentage of cells entering apoptosis. The data presented suggest that ShcA proteins can play a role in committing CD4(+) T-cells to apoptosis, as a response to HIV-1 infection.
Insights
ShcA proteins in CD4(+) T-cells are crucial for initiating apoptosis during HIV-1 infection. Inhibiting these proteins reduces cell death and increases HIV-1 particle production, revealing a key mechanism in viral pathogenesis.
Area of Science:
- Molecular Biology
- Immunology
- Virology
Background:
- HIV-1 infection leads to CD4(+) T-cell depletion, with apoptosis implicated as a key mechanism.
- Shc proteins (ShcA, ShcB, ShcC) are involved in cellular signaling, differentiation, and stress-induced apoptosis.
- Two ShcA splicing variants, p46Shc and p52Shc, are expressed in T-lymphocytes.
Purpose of the Study:
- To investigate the role of ShcA proteins (p46Shc and p52Shc) in HIV-1 infection of CD4(+) T-cells.
- To determine the impact of ShcA inhibition on HIV-1 replication and T-cell apoptosis.
Main Methods:
- Utilized a dominant-negative mutant to inhibit p46Shc and p52Shc function in CD4(+) T-cells.
- Quantified HIV-1 particle production and viral gene expression efficiency.
- Assessed the percentage of CD4(+) T-cells undergoing apoptosis.
Main Results:
- Inhibition of p46Shc and p52Shc significantly enhanced HIV-1 particle production.
- Viral gene expression efficiency remained unaffected by ShcA inhibition.
- A decrease in the percentage of CD4(+) T-cells entering apoptosis was observed in cells with inhibited ShcA.
Conclusions:
- ShcA proteins play a role in mediating CD4(+) T-cell apoptosis in response to HIV-1 infection.
- The findings suggest ShcA proteins are involved in the host's apoptotic response, potentially influencing HIV-1 pathogenesis.
