RESUMO
Toll-like receptors (TLRs) are the best-studied family of pattern-recognition receptors (PRRs), whose task is to rapidly recognize evolutionarily conserved structures on the invading microorganisms. Through binding to these patterns, TLRs trigger a number of proinflammatory and anti-microbial responses, playing a key role in the first line of defence against the pathogens also promoting adaptive immunity responses. Growing amounts of data suggest that single nucleotide polymorphisms (SNPs) on the various human TLR proteins are associated with altered susceptibility to infection. This review summarizes the role of TLRs in innate immunity, their ligands and signalling and focuses on the TLR SNPs which have been linked to infectious disease susceptibility.
Assuntos
Predisposição Genética para Doença , Imunidade Inata/genética , Infecções , Polimorfismo de Nucleotídeo Único/imunologia , Receptores Toll-Like , Humanos , Infecções/genética , Infecções/imunologia , Receptores Toll-Like/genética , Receptores Toll-Like/imunologiaRESUMO
Preterm birth represents a major problem for modern obstetrics due to its increasing frequency and the accompanying socioeconomic impact. Although several maternal characteristics related to preterm birth have been identified, the etiology in most cases remains inadequately understood. Various microorganisms have been linked to the pathogenesis of preterm birth. Microbes may reach the amniotic cavity and fetus by ascending from the vagina and cervix, by hematogenous distribution through the placenta, by migration from the abdominal cavity through the fallopian tubes, or through invasive medical procedures. Organisms commonly cultured from the amniotic cavity following preterm delivery include Ureaplasma urealyticum, Mycoplasma hominis, Bacteroides spp., Gardnerella vaginalis, Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, and group B hemolytic streptococci. Several trials have examined the effect of antibiotic administration to patients with preterm labor and intact membranes, preterm premature rupture of the membranes, genital mycoplasmal infection, asymptomatic bacteriuria, and bacterial vaginosis. The results of such studies, which were variable and often conflicting, are discussed here.