Differential production of IFN-γ, analyzed at the single-cell level, by specific subsets of human NK and T cells from healthy and HIV+ subjects
✍ Scribed by Marco Vitale; Arnaldo Caruso; Stefano Licenziati; Luigi Rodella; Simona Fiorentini; Giorgio Zauli; Francesco Castelli; Francesco A. Manzoli; Adolfo Turano
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 189 KB
- Volume
- 39
- Category
- Article
- ISSN
- 0196-4763
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✦ Synopsis
Background: Interferon gamma is a cytokine that plays a central role in immunity, and is physiologically secreted by T and NK cells under appropriate stimuli during the immune response. By means of flow cytometry, we performed a single cell analysis of interferon gamma producing NK cells and their surface phenotype in normal and HIV ϩ individuals that show several defects of cytokine production and cellular immunity. Methods: PBMC or purified NK cells were stimulated for 1-12 h with PMA/ionomycin in the presence of monensin, subsequently stained for surface CD56 and CD3 or CD8, and for intracytoplasmic IFN-␥, and analysed by flow cytometry. Results: Our results show that CD56 ϩ NK cells are more efficient interferon gamma producers than T cells. Moreover, within the CD56 ϩ NK cell population, those that co-express low density CD8 are the best producers. Fi-nally, we show that NK cells during HIV infection are more massively recruited to interferon gamma production than those from normal subjects. Conclusions: Both in the normal and HIV ϩ subjects, a higher percentage of NK cells than T cells can produce IFN-␥ although differences can be identified within the NK cells subset in terms of IFN-␥ production. The production of IFN-␥ is fully achievable in the HIV ϩ subjects, which is consistent with their elevated plasmatic levels of the cytokine. The possibility that NK cells that produce interferon gamma could represent a functionally distinct population committed to the production of this cytokine, is discussed.