RESUMEN
We invetigated the influence of hogh concentrations of glutamine and aspargine on in vitro cellular growth of lymphocytes stimulated with phytohaemaglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM), a recognized test of cellular immunocompetence. Human peripheral lymphocytes were cultured in flat-bottomed 96-well microplates at 37§ C for 96 (PHA and Con A) or 144 hours (PWM) in the presence of a mitogen at different concentrations and either glutamine or asparagine supplemented at doses of 2, 4 or 8 mM. Lymphocyte reactivity, meas ured by the incorporation of tritiated thymidine into cellular DNA, was compared to identical cultures in the absence of supplemented amino acids (controls). We found that glutamine in doses of 2 mM and higher inhibited lymphocyte proliferation of mitogen-stimulated human lymphocyes, whereas asparagine caused no effect. These results demonstrate that, although necessary for cellular division in moderate amounts, glutamine in high concentrations has the reverse effect
Asunto(s)
Humanos , Glutamina , Terapia de Inmunosupresión , Técnicas In Vitro , LinfocitosRESUMEN
Recurrent infections are common features in patients affected by various aminoacidopathies. Since these disorders are biochemically characterized by tissue accumulation of amino acids, it is possible that these compounds may act as immunosuppressants. We therefore investigated the influence of 21 amino acids on in vitro cellular growth of lymphocytes stimulated with phytohaemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM), a recognized test of cellular immunocompetence. Human peripheral lymphocytes were cultured in flat-bottomed 96-well microplates at 37 degrees C for 96 (PHA and Con A) or 144 h (PWM) in the presence of one mitogen at different concentrations and of one amino acid added at doses of 2, 4 or 8 mM. Cell reactivity was measured by the incorporation of tritiated thymidine into cellular DNA and compared to that of identical cultures with no amino acids added (controls). We found that among the 21 amino acids tested, cysteine stimulated lymphocyte growth, whereas glutamate, tryptophan, phenylalanine and glutamine caused significant inhibition. These results may reflect an immunomodulatory role for some amino acids.