RESUMO
The cytotoxic activity on influenza virus-infected Epstein-Barr virus (EBV)-transformed B-lymphoblastoid cell lines (LCL-Flu) and influenza virus-infected phytohemagglutinin lymphoblasts (PHA-Flu) was compared with the use of influenza-A virus-specific cytotoxic T lymphocytes (CTL), generated in short-term bulk cultures. Cold-target inhibition experiments showed that the lysis of PHA-Flu was completely blocked by both cold LCL-Flu and cold PHA-Flu whereas the lysis of LCL-Flu was completely inhibited by cold LCL-Flu, but only partially by cold PHA-Flu, indicating that structures can be recognized on LCL-Flu which are absent from PHA-Flu. Monoclonal antibody (McAb) directed against a monomorphic determinant of major histocompatibility complex (MHC) class I molecules inhibited the lysis of PHA-Flu more strongly than the lysis of LCL-Flu. Since LCL have a high expression of MHC class II molecules compared to PHA lymphoblasts, we examined whether class II-restricted CTL activity was responsible for the (anti)class I McAb-resistant lysis of LCL-Flu. Neither anti-CD4 McAb nor anti-class II McAb inhibited the lysis of LCL-Flu which argues against a contribution of MHC class II-restricted CTL. Depletion of CD16+ cells, containing the majority of the nonspecific cytotoxic cells, did not affect the lysis of LCL-Flu, indicating that the remaining lysis on LCL-Flu was also not due to a nonspecific component. We suggest that cell-type-dependent variations exist in the nature of the immunogenic determinants to which CTL respond.
Assuntos
Linfócitos B/microbiologia , Orthomyxoviridae/imunologia , Linfócitos T Citotóxicos/imunologia , Anticorpos Monoclonais , Antígenos de Diferenciação de Linfócitos T/análise , Linfócitos B/imunologia , Linhagem Celular , Citotoxicidade Imunológica , Antígenos HLA/imunologia , Humanos , Imunidade Celular , Técnicas In Vitro , Complexo Principal de Histocompatibilidade , Fito-Hemaglutininas/farmacologiaAssuntos
Cyprinidae/crescimento & desenvolvimento , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Desenvolvimento Muscular , Neurônios/enzimologia , Medula Espinal/crescimento & desenvolvimento , Succinato Desidrogenase/metabolismo , Peixe-Zebra/crescimento & desenvolvimento , Envelhecimento , Animais , Músculos/enzimologia , Medula Espinal/enzimologiaRESUMO
Significant differences of taste thresholds for different sugars, salt, organic acids, and bitter products, observed in human populations in contrasted environments, are related to potential variations of traditional diet. In this respect, biochemical composition of the environment would be the major selective pressure for taste perception.