RESUMEN

We prospectively studied 37 HIV-1 uninfected persons engaging in repeated high risk sexual activity with an HIV-1 infected partner, as well as 18 of their infected partners. Only one subject (3%) demonstrated the homozygous 32-bp deletion delta32delta32 of the HIV-1 co-receptor CCR5. CD4+ cells from all high risk subjects except the delta32delta32 CCR5 homozygote were susceptible in vitro to both CCR5-dependent and CXCR4-dependent HIV-1 strains. Median HIV-1 plasma RNA levels of the infected partners were not significantly different from levels of matched infected controls. Thirteen subjects demonstrated HIV-1 specific CTL at one or more visits, and these activities were more commonly observed in persons with the wild type CCR5 genotype. These results indicate that cellular immunity rather than inheritance of the delta32 CCR5 mutation accounts more often for persistently HIV-1-resistant cases.

Asunto(s)

Linfocitos T CD4-Positivos/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Adulto , Linfocitos T CD4-Positivos/virología , Femenino , Infecciones por VIH/virología , Humanos , Inmunidad Celular , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Receptores CCR5/genética , Receptores CCR5/inmunología , Receptores CXCR4/genética , Receptores CXCR4/inmunología , Eliminación de Secuencia , Parejas Sexuales

RESUMEN

Chalcone-synthase (CHS) activity was followed during the development of primary leaves of oat (Avena sativa L.) seedlings grown under different illumination conditions. Continuous darkness and continuous light resulted in similar time courses of enzyme activity. The maximum of CHS activity in etiolated leaves was delayed by 1 d and reached about half the level of that of light-grown leaves. In seedlings grown under defined light-dark cycles a diurnal rhythm of CHS activity and its protein level was observed which followed the rhythm of CHS-mRNA translational activity (Knogge et al. 1986). This rhythm persisted in continuous light after a short-term pre-exposure to the light-dark cycle but not in continuous darkness.