RESUMO
The present study examines antigenic variability for the human whipworm Trichuris trichiura. Recognition by IgG of somatic antigens of individual worms collected from 3 intensely infected children from Jamaica, West Indies has been investigated by immunoblotting. When probed with 1 plasma sample, significant differences in recognition of 2 selected antigens among worm populations and between male and female worms was observed. In addition, there was evidence for antigenic variability within worm populations at the individual worm level. Such variations may have considerable implications for the development of immunity to parasitic nematodes.(AU)
Assuntos
21003 , Criança , Feminino , Humanos , Masculino , Variação Antigênica , Antígenos de Helmintos/sangue , Antígenos de Helmintos/imunologia , Tricuríase/imunologia , Tricuríase/parasitologia , Trichuris/imunologia , Western Blotting , Eletroforese em Gel de Poliacrilamida , Interações Hospedeiro-Parasita , Fatores Sexuais , Estatísticas não Paramétricas , Tricuríase/imunologiaRESUMO
The present study compares parasite-specific antibody responses in two Caribbean communities with high and low levels of Trichuris trichiura transmission. The age-dependency of antibody levels suggest that IgG1 and IgG2 levels relate to the current intensity of infection (as assessed by density of eggs in stool (e.p.g.) and reflect the age-intensity profile at the population level. IgG4, IgE and IgA levels persist into early adulthood and the subsequent decline is gradual. In the low transmission area, lower infection levels are reflected in lower parasite-specific antibody levels (of all isotypes) in the community as a whole. Despite a significantly greater past experience of infection in the high transmission area, antibody levels are not maintained at significantly higher levels throughout adulthood. The production of IgA appears to require a threshold for triggering, and a vigorous IgA response is maintained into early adulthood only in the high transmission village where peak intensity is greatest and the age-convexity of intensity is most marked. Experimental and theoretical studies focusing on the dynamic nature of host-helminth interactions in hosts exposed to high and low infection levels, and the putative role of acquired immunity, are discussed in relation to the data presented.