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.
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 (n=9) and HIV-infected (n=10) 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.
Kourtis
Athena P
AP
Division of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA. apk3@cdc.gov
Ibegbu
Chris C
CC
Theiler
Regan
R
Xu
Yong-Xian
YX
Bansil
Pooja
P
Jamieson
Denise J
DJ
Lindsay
Michael
M
Butera
Salvatore
S
Duerr
Ann
A
D023241:Antiretroviral Therapy, Highly Active; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D016022:Case-Control Studies; D005260:Female; D005434:Flow Cytometry; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy / Q000276:immunology* / Q000821:virology; D015497:HIV-1 / Q000502:physiology; D006801:Humans; D016130:Immunophenotyping; D007231:Infant, Newborn; D008895:Milk, Human / Q000166:cytology*; D011247:Pregnancy; D019713:Receptors, CCR5 / Q000378:metabolism*; D019718:Receptors, CXCR4 / Q000378:metabolism*; D019562:Viral Load
D019713:Receptors, CCR5; D019718:Receptors, CXCR4