The integrin alpha4beta7 forms a complex with cell-surface CD4 and defines a T-cell subset that is highly susceptible to infection by HIV-1.

Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Proceedings of the National Academy of Sciences (Impact Factor: 9.81). 11/2009; 106(49):20877-82. DOI: 10.1073/pnas.0911796106
Source: PubMed

ABSTRACT Both activated and resting CD4(+) T cells in mucosal tissues play important roles in the earliest phases of infection after sexual transmission of HIV-1, a process that is inefficient. HIV-1 gp120 binds to integrin alpha(4)beta(7) (alpha(4)beta(7)), the gut mucosal homing receptor. We find that alpha(4)beta(7)(high) CD4(+) T cells are more susceptible to productive infection than are alpha(4)beta(7)(low-neg) CD4(+) T cells in part because this cellular subset is enriched with metabolically active CD4(+) T cells. alpha(4)beta(7)(high) CD4(+) T cells are CCR5(high) and CXCR4(low); on these cells, alpha(4)beta(7) appears in a complex with CD4. The specific affinity of gp120 for alpha(4)beta(7) provides a mechanism for HIV-1 to target activated cells that are critical for efficient virus propagation and dissemination following sexual transmission.

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