Phenotypically and functionally distinct subsets contribute to the expansion of CD56 super(-)/CD16 super(+) natural killer cells in HIV infection

• Published in: AIDS (London) Vol. 24; no. 12; pp. 1823 - 1834
• Main Authors: Hong, H S, Eberhard, J M, Keudel, P, Bollmann, BA, Ahmad, F, Ballmaier, M, Bhatnagar, N, Zielinska-Skowronek, M, Schmidt, R E, Meyer-Olson, D
• Format: Journal Article
• Language: English
• Published: 01.01.2010
• Subjects: Human immunodeficiency virus
• ISSN: 0269-9370
• DOI: 10.1097/QAD.0b013e32833b556f

Objective: Chronic HIV infection has been associated with activation and increased turnover of natural killer (NK) cells as well as with disturbed homeostasis of the NK cell compartment, including loss of CD56 super(+) NK cells and accumulation of dysfunctional CD56 super(-)/CD16 super(+) NK cells. We performed a comprehensive phenotypical and functional characterization of this population. Design: A cross-sectional study was performed to analyze CD56 super(-)/CD16 super(+) NK cells from 34 untreated HIV-infected and 15 seronegative individuals. Methods: NK cells were analyzed by flow cytometry. Degranulation was assessed by measuring their expression of CD107a after stimulation with K562 cells, interleukin-12 and interleukin-15. Results: CD56 super(-)/CD16 super(+) NK cells are heterogeneous and composed of two populations, namely CD122 super(-)/CCR7 super(+) cells and CD122 super(+)/CCR7 super(-) cells. We show that expanded CD122 super(+) but not CCR7 super(+) cells in HIV-seropositive individuals are characterized; by expression of senescence marker CD57 similarly to CD56 super(dim)/CD16 super(+) NK cells along with expression of KIRs, CD8, perform and granzyme B. Despite expression of perforin and granzyme B, CD57 expressing cells exhibited less numbers of degranulating cells as measured by CD107a, indicating their functional impairment. However; there was no correlation between expansion of total CD56 super(-)/CD16 super(+) NK cells or the distinct subpopulations and viral load or CD4 cell count. Conclusion: These data indicate that expansion of CD56 super(-)/CD16 super(+) cells in HIV infection is driven by a distinct subset within this population with high expression of terminal differentiation marker with a phenotype resembling CD56 super(dim)/CD16 super(+) NK cells.