Human Immunodeficiency Virus-Specific CD8 super(+) T Cells in Human Breast Milk

• Published in: Journal of virology 2002-08, Vol.76 (15), p.7365-7373
• Main Authors: Sabbaj, S, Edwards, B H, Ghosh, M K, Semrau, K, Cheelo, S, Thea, D M, Kuhn, L, Ritter, G D, Mulligan, MJ, Goepfert, P A, Aldrovandi, G M
• Format: Article
• Language: English
• ISSN: 0022-538X
• DOI: 10.1128/JVI.76.15.7365-7373.2002

Breast-feeding infants of human immunodeficiency virus (HIV)-infected women ingest large amounts of HIV, but most escape infection. While the factors affecting transmission risk are poorly understood, HIV-specific cytotoxic T- lymphocyte (CTL) responses play a critical role in controlling HIV levels in blood. We therefore investigated the ability of breast milk cells (BMC) from HIV-infected women from the United States and Zambia to respond to HIV-1 peptides in a gamma interferon enzyme-linked immunospot assay. All (n = 11) HIV-infected women had responses to pools of Gag peptide (range, 105 to 1,400 spot-forming cells/million; mean = 718), 8 of 11 reacted to Pol, 7 reacted to Nef, and 2 of 5 reacted to Env. Conversely, of four HIV-negative women, none responded to any of the tested HIV peptide pools. Depletion and tetramer staining studies demonstrated that CD8 super(+) T cells mediated these responses, and a chromium-release assay showed that these BMC were capable of lysing target cells in an HIV-specific manner. These data demonstrate the presence of HIV- specific major histocompatibility complex class I-restricted CD8 super(+) CTLs in breast milk. Their presence suggests a role in limiting transmission and provides a rationale for vaccine strategies to enhance these responses.