Interleukin-2-activated rat natural killer cells express inducible nitric oxide synthase that contributes to cytotoxic function and interferon-gamma production.
Blood
; 93(11): 3876-84, 1999 Jun 01.
Article
en En
| MEDLINE
| ID: mdl-10339496
ABSTRACT
Natural killer (NK) cells are large granular lymphocytes capable of destroying cells infected by virus or bacteria and susceptible tumor cells without prior sensitization and restriction by major histocompatability complex (MHC) antigens. Their cytotoxic activity could be strongly enhanced by interleukin-2 (IL-2). Previous findings, even if obtained with indirect experimental approaches, have suggested a possible involvement of the inducible nitric oxide (iNOS) pathway in the NK-mediated target cell killing. The aim of the present study was first to directly examine the induction of iNOS in IL-2-activated rat NK cells isolated from peripheral blood (PB-NK) or spleen (S-NK), and second to investigate the involvement of the iNOS-derived NO in the cytotoxic function of these cells. Our findings clearly indicate the induction of iNOS expression in IL-2-activated PB-NK and S-NK cells, as evaluated either at mRNA and protein levels. Accordingly, significantly high levels of iNOS activity were shown, as detected by the L-arginine to L-citrulline conversion in appropriate assay conditions. The consequent NO generation appears to partially account for NK cell-mediated DNA fragmentation and lysis of sensitive tumor target cells. In fact, functional inhibition of iNOS through specific inhibitors, as well as the almost complete abrogation of its expression through a specific iNOS mRNA oligodeoxynucleotide antisense, significantly reduced the lytic activity of IL-2-activated NK cells. Moreover, IL-2-induced interferon-gamma production appears also to be dependent, at least in part, on iNOS induction.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Células Asesinas Activadas por Linfocinas
/
Interferón gamma
/
Óxido Nítrico Sintasa
/
Citotoxicidad Inmunológica
Límite:
Animals
Idioma:
En
Revista:
Blood
Año:
1999
Tipo del documento:
Article
País de afiliación:
Italia