Human Beta-Defensin 2 and 3 Inhibit HIV-1 Replication in Macrophages

Area of Science:

• Immunology
• Virology
• Antimicrobial Peptides

Background:

• Human beta-defensins (hBDs) are antimicrobial peptides known to inhibit HIV-1 in CD4+ T cells.
• Macrophages are crucial for HIV persistence and spread, and contribute to HIV-associated complications.
• The role of hBDs in protecting macrophages from HIV remains largely unexplored.

Purpose of the Study:

• To investigate the potential of hBDs, specifically hBD2 and hBD3, in inhibiting HIV replication in primary human monocyte-derived macrophages (MDM).
• To elucidate the mechanism by which hBD2 inhibits HIV in MDM, including receptor usage and signaling pathways.

Main Methods:

• In vitro studies using primary human MDM exposed to HIV.
• Dose-response experiments to assess hBD2 and hBD3 inhibition of HIV replication.
• Analysis of HIV receptor expression, cytokine/chemokine induction, G-protein coupled receptor (GPCR) signaling, and antiretroviral restriction factors (APOBEC3A/3G).

Main Results:

• hBD2 and hBD3 demonstrated dose-dependent inhibition of HIV replication in MDM.
• hBD2 inhibited HIV at an early post-entry stage via GPCR-mediated signaling, independent of CCR2 and CCR6.
• hBD2 treatment increased the expression of APOBEC3A and 3G antiretroviral restriction factors in MDM.

Conclusions:

• hBD2 and hBD3 effectively inhibit HIV replication in macrophages, suggesting a broader role for hBDs in HIV defense.
• hBD2's mechanism involves GPCR signaling and upregulation of APOBEC3 restriction factors, indicating a multi-faceted antiviral effect.
• These findings highlight the therapeutic potential of beta-defensins for HIV prevention and treatment, particularly targeting macrophage reservoirs.