RESUMEN
The major virulence factor of Streptococcus pyogenes, the M protein, is positively regulated at the transcriptional level by mry in the M type 6 strain studied. We show here that in two S. pyogenes strains isolated from cases of toxic-shock-like syndrome, a type M1 strain and a type M3 strain, an mry-like gene is also required for resistance to phagocytosis.
Asunto(s)
Antígenos Bacterianos , Proteínas de la Membrana Bacteriana Externa , Proteínas Bacterianas/genética , Proteínas Portadoras , Genes Bacterianos , Choque Séptico/microbiología , Streptococcus pyogenes/genética , Streptococcus pyogenes/patogenicidad , Proteínas Bacterianas/metabolismo , Fibrinógeno/metabolismo , Humanos , Mutagénesis Insercional , Fagocitosis , Unión Proteica , Choque Séptico/etiología , Choque Séptico/inmunología , Streptococcus pyogenes/inmunología , Virulencia/genéticaRESUMEN
The renin-angiotensin system is a major regulator of body sodium, predominantly through the actions of intrarenal angiotensin II of unclear origin. We show that polarized epithelium of the proximal tubule synthesizes and secretes angiotensinogen at its apical side and that the protein can be detected in urine as a function of dietary sodium. Furthermore, we demonstrate that renin is expressed and secreted in a restricted nephron segment, the connecting tubule, also in a sodium-dependent fashion. A paracrine renin-angiotensin system operating along the entire nephron may contribute to long-term arterial pressure regulation by integrating distant tubular sodium-reabsorbing functions.