Abstract
The immune response to a virus infection involves both nonspecific and specific immune mechanisms. Natural killer (NK) cells are naturally-occurring cytolytic cells capable of lysing various tumor cells and virus-infected cells without previous sensitization or with a requirement for major histocompatibility (MHC) restriction. The molecular mechanisms that explain how NK cells are able to kill virus-infected cells and tumor cells while sparing self-cells have recently been elucidated (1). NK cells may play a role as a first line of defense against virus infection by mediating lysis of virus-infected cells prior to the development of specific humoral and cell-mediated defense mechanisms. Although the percentage of NK cells in HIV-1-infected patients may remain normal, the absolute numbers of some NK subsets are substantially reduced in the blood of HIV-1 patients and NK function decreases as HIV-1 infection proceeds (2–4). The interplay between NK cells and other cells of the innate and specific immune system is mediated, in part, through the release of cytokines, in particular interleukin-2 (IL-2) and γ-interferon (γ-IFN). Thus, it seems plausible that the generalized immunosuppression seen in HIV-1-infected patients may contribute to the impairment of NK activity. A dynamic balance between NK cells and cytotoxic T lymphocytes (CTL) is likely to occur (5). Therefore, any alterations in NK or CTL activity are likely to impair anti-HIV-1 cytolytic function.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Moretta, A., Bottino, C, Vitale, M., Pende, D., Biassoni, R., Mingari, M. C., and Moretta, L. (1996) Receptors for HLA class-I molecules in human natural killer cells. Ann. Rev. Immunol. 14, 619–648.
Cai, Q., Huang, X.-L. Rappocciolo, G., and Rinaldo, C. R. (1990) Natural killer cell response in homosexual men with early HIV infection. J. Acq. Immune Defic. Syndr. 3, 669–676.
Ullum, H., Gotzsche, P. C., Victor, J., Dickmeiss, E., Skinhoj, P., and Pederson, B. K. (1995) Defective natural immunity: an early manifestation of human immunodeficiency virus infection. J. Exp. Med. 182, 789–799.
Hu, P-F., Hultin, L. E., Hultin, P. Hausner, M. A., Hirji, K., Jewett, A., et al (1995) Natural killer cell immunodeficiency in HIV disease is manifest by profoundly decreased numbers of CD16+CD56+ cells and expansion of a population of CD16dimCD56“ cells with low lytic activity. J. Acq. Imm. Def. Synd. 10,331–340.
Kos, F. J. and Engleman, E. G. (1996) Immune regulation: a critical link between NK and CTLs. Immunol. Today 17, 174–176.
Blomberg, K., Granberg, C., Hemmila, I., and Lovgren, T. (1986) Europium-labeled target cells in an assay of natural killer cell activity. I. A novel non-radioactive method based on time-resolved fluorescence. J. Immunol. Methods 86, 225–233.
Blomberg, K., Hautala, R., Lovgren, J., Mukkala, V. M., Lindqvist, C., and Akerman, K. (1996) Time resolved fluorimetric assay for natural killer activity using target cells labeled with a fluorescence enhancing ligand. J. Immunol. Methods 193, 199–206.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1999 Humana Press Inc., Totowa, NJ
About this protocol
Cite this protocol
Cox, J.H. (1999). Evaluation of Natural Killer Cell Activity. In: Michael, N.L., Kim, J.H. (eds) HIV Protocols. Methods in Molecular Medicine™, vol 17. Humana Press. https://doi.org/10.1385/0-89603-369-4:383
Download citation
DOI: https://doi.org/10.1385/0-89603-369-4:383
Publisher Name: Humana Press
Print ISBN: 978-0-89603-369-6
Online ISBN: 978-1-59259-601-0
eBook Packages: Springer Protocols