Table 2 Anti-HIV activity of human defensins
From: Host factors influencing susceptibility to HIV infection and AIDS progression
Defensins | Regulation | Cell Source | Mechanisms | References |
|---|---|---|---|---|
α-Defensins |  |  |  |  |
HNP1, HNP2, and HNP3 | Constitutive HPN2 may be the product of proteolytic processing of HNP1/HPN3 | Neutrophils and promyelocytes | • CD4 down-modulation • Viral membrane disruption and binding to CD4 and gp120 (in absence of serum) • Upregulation of CC-chemokines in macrophages • Block of nuclear transport (by HNP1) | 131, 143, 146 |
HNP4 | Constitutive | Neutrophils | • Unknown (lectin-independent mechanism) | 135 |
β-Defensins |  |  |  |  |
HBD2 and HBD3 | Inducible by HIV, opportunistic infections, and pro-inflammatory cytokines (TNF, IL-1B) | Epithelial cells, monocytes, monocytes-derived DCs, macrophages, and keratinocytes | • Viral membrane disruption (absence of serum) • CXCR4 down-modulation • CCR6-mediated chemotactic effects | 148–151 |
θ-Defensins |  |  |  |  |
Retrocyclins (RTD1, RTD2) | Synthesis blocked in humans by premature termination codon | RNA transcripts, not protein, expressed in bone marrow | • Prevent HIV entry by binding to CD4 and gp120 | 138–140 |