Breast Milk CD4+ T Cells Express High Levels of C Chemokine Receptor 5 and CXC Chemokine Receptor 4 and Are Preserved in HIV‐Infected Mothers Receiving Highly Active Antiretroviral Therapy
1Division of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, and 2Laboratory Branch, Division of HIV/AIDS Prevention, National Center for HIV, STD and TB Prevention, Centers for Disease Control and Prevention, and 3Center for AIDS Research Immunology Core Laboratory, Emory Vaccine Center and 4Department of Gynecology and Obstetrics, Emory University School of Medicine, Atlanta, Georgia; 5Department of Obstetrics and Gynecology, Eastern Virginia Medical School, Norfolk
Background.
Transmission of human immunodeficiency virus (HIV) to the infant through breast‐feeding is a major problem worldwide; however, the biological circumstances of such transmission remain unclear. Little characterization of breast milk CD4+ T lymphocytes has been done so far.
Methods.We performed a detailed immunophenotypic analysis of T lymphocytes in the breast milk, compared with the blood, of HIV‐uninfected (
) and HIV‐infected (
) women receiving highly active antiretroviral therapy, by use of multiparameter flow cytometry. Descriptive statistics and nonparametric comparisons were performed using SAS software (version 9.1; SAS Institute).
Results.In uninfected women, 44%–78% of breast milk CD4+ T cells expressed the C chemokine receptor 5 (CCR5), whereas 26%–73% of cells coexpressed CCR5 and CXC chemokine receptor 4 (CXCR4). In contrast, only 7%–20% of peripheral blood CD4+ T cells expressed CCR5 and 1%–20% coexpressed CCR5 and CXCR4. The level of CCR5 expression in CD4+ T cells in breast milk was higher than in blood. In HIV‐infected women, the high frequency of CD4+CCR5+ T cells in breast milk was preserved.
Conclusions.A majority of CD4+ T cells in breast milk express high levels of CCR5 and CXCR4. Unlike other mucosal immune sites, in which CD4+CCR5+ T cells are rapidly eliminated by HIV, these cells are preserved in breast milk during HIV infection.
Received 31 July 2006; accepted 4 November 2006; electronically published 20 February 2007.
Cited by
Online publication date: 1-Jul-2009.
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Online publication date: 1-Dec-2008.
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Potential conflicts of interest: none reported.
Financial support: Centers for Disease Control and Prevention.
The findings and conclusions in this article are those of the authors and do not necessarily represent the views of the funding agency.