Expression of HLA class I-specific inhibitory natural killer cell receptors in HIV-specific cytolytic T lymphocytes: Impairment of specific cytolytic functions

A. De Maria, A. Ferraris, M. Guastella, S. Pilia, C. Cantoni, L. Polero, M. C. Mingari, D. Bassetti, A. S. Fauci, L. Moretta

Research output: Contribution to journalArticle


Human T lymphocytes have been shown to express inhibitory natural killer cell receptors (NKR), which can down-regulate T cell antigen receptor- mediated T cell function, including cytolytic activity. In the present study, we demonstrate that CD3+NKR+ cells can be identified in HIV-infected patients. HIV-specific cytolytic activity was analyzed in five patients in whom autologous lymphoblastoid B cell lines could be derived as a source of autologous target cells. Phytohemagglutinin-activated T cell populations that had been cultured in interleukin 2 displayed HIV-specific cytotoxic T lymphocyte (CTL) activity against HIV env, gag, pol, and Nef in 3 of 5 patients. Addition of anti-NKR mAb of IgM isotype could increase the specific CTL activity. Moreover, in one additional patient, HIV-specific CTL activity was undetectable; however, after addition of anti-NKR mAb such CTL activity appeared de novo. Similar results were obtained by analysis of CD3+NKR+ clones derived from two patients. These data provide direct evidence that CD3+NKR+ cells may include antigen (HIV)-specific CTLs and that mAb- mediated masking of inhibitory NKR may revert the down-regulation of CTL function.

Original languageEnglish
Pages (from-to)10285-10288
Number of pages4
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number19
Publication statusPublished - 1997


ASJC Scopus subject areas

  • Genetics
  • General

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