RESUMO
Adult Onchocerca volvulus worms obtained by enzyme digestion from nodules of infected Mexicans were radio-isotope labelled by the chloramine-T or Bolton-Hunter methods. No antigenic determinants were detected in extracts of worms labelled by the chloramine-T method but 3 antigens were detected in extracts of the Bolton-Hunter labelled worms. Two were present in such small amounts that it was impractical to investigate them further, but a major component of mol. wt 20 kDa was purified by gel filtration and used in a serological survey of inhabitants of villages in Southern Mexico. Using the 20 kDa antigen, which is superficially located on both sexes of O. volvulus, sera from both non-endemic and endemic regions were analysed by radio-immunoprecipitation of this antigen. In Southern Mexico, the average sensitivity of the test was 92%, and the specificity 98%. Whilst the 20 kDa antigen did not detect antibodies in the sera of Trinidadians infected with Wuncheria bancrofti or Mansonella ozzardi, this antigen detected high levels of antibodies in Indians exposed to W. bancrofti.
Assuntos
Antígenos de Helmintos/análise , Onchocerca/imunologia , Oncocercose/diagnóstico , Animais , Anticorpos/análise , Especificidade de Anticorpos , Precipitação Química , Cromatografia em Gel , Reações Cruzadas , Eletroforese em Gel de Poliacrilamida , Feminino , Humanos , Radioisótopos do Iodo , Masculino , México , SolubilidadeRESUMO
Surface molecules of parasitic stages of the nematode Nippostrongylus brasiliensis can be readily iodinated by the chloramine T technique, and assessed for antigenic reactivity with humoral antibody from infected animals. Free-living infective larvae are less amenable to analysis by this, or similar methods, but within 18 hr of larvae entering the host, new macromolecular surface antigens can be detected. The parasites change their surface antigens twice more in the course of the maturation to the adult stage. Surface antigens are stage-specific: lung larvae (L3), intestinal larvae (L4) and gut-living adults each possess characteristic sets of cuticular molecules. Single stage infections result in antibody reactive only to the antigens from the homologous stage. The adult surface appears to bear the greatest number of antigens, one of which is found only on the male worm. The composition of these antigens does not differ grossly between adult worms from a naive or immune host, or worms established after the adaptation of a 'trickle' (multiple low dose) infection. There appears to be an interesting contrast between the rapidity and extent of changes in surface antigens in the early phases of infection, and the stability of adult antigens analysed at different points in the host immune response.
Assuntos
Antígenos de Superfície/análise , Epitopos/análise , Nippostrongylus/imunologia , Animais , Formação de Anticorpos , Eletroforese em Gel de Poliacrilamida , Feminino , Masculino , Peso Molecular , Ratos , Ratos Endogâmicos , Fatores Sexuais , Fatores de TempoRESUMO
A previous report showed that infection with the nematode Nippostrongylus brasiliensis stimulates a basophilia as well as an eosinophilia in the blood of August rats. The present study shows that blood levels of basophils and eosinophils were increased in two other rat strains, one inbred and one outbred, after infection with N. brasiliensis, and infection of two inbred rat strains with Trichinella spiralis also stimulated a basophilia as well as an eosinophilia. No increase occurred in basophils or eosinophils in athymic (nude) rats infected with N. brasiliensis, although both these cell types were found in the blood of control, specific pathogen free, nude rats in numbers comparable to those in specific pathogen free, heterozygote controls of the same strain. Rat basophils usually have few granules and in blood smears often appear as if they were partly degranulated. Basophils from uninfected nude rats contained more negative than positive staining granules compared with basophils from parasitized heterozygotes. The possession of small numbers of granules which vary in their reaction to stains of the Romanowski type is a normal feature of rat basophils in blood smears. Consequently rat basophils differ in these respects from those of other species.
Assuntos
Basófilos , Eosinófilos , Infecções por Nematoides/sangue , Ratos Endogâmicos/genética , Triquinelose/sangue , Animais , Basófilos/imunologia , Eosinófilos/imunologia , Heterozigoto , Contagem de Leucócitos , Infecções por Nematoides/imunologia , Nippostrongylus , Ratos , Organismos Livres de Patógenos Específicos , Timo/fisiologia , Triquinelose/imunologiaRESUMO
The course of each of three successive infections with Eimeria nieschulzi in nude (athymic) rats was the same as the primary infection in nu/+ animals, with the production of more oocysts. This indicates that resistance to reinfection with this parasite is mediated by T lymphocytes but that these cells do not control the duration of the life cycle, since oocyst production was not prolonged in the nu/nu rats. After the three infections with E. nieschulzi, the rats were exposed twice to the intestinal nematode Nippostrongylus brasiliensis, and the nu/nu were completely susceptible even to the second infection. Egg production by both infections in the nu/nu animals was similar and continued at a high plateau level for 28 days before falling to a low level. It appears that the strain of N. brasiliensis used in this study is unable to sustain high egg production for more than 4 weeks in T cell deficient rats.
Assuntos
Coccidiose/imunologia , Enteropatias Parasitárias/imunologia , Infecções por Nematoides/imunologia , Animais , Eimeria/imunologia , Masculino , Nippostrongylus/imunologia , Ratos , Timo/anormalidadesRESUMO
The expulsion of antibody-damaged Nippostrongylus brasiliensis nematodes from the intestine of rats irradiated with 750 rad 60Co was induced by thoracic duct lymph (TDL) or mesenteric lymph node (MLN) cells apparently without the help of bone marrow-derived cells. The effector cells were present in the TDL or MLN of rats by the 8th day after infection and could be recovered from the peritoneal cavity. The ability of TDL cells to transfer immunity to irradiated recipients was undiminished when the cells with immunoglobulin on their surface were removed. These results suggest that, following antibody damage, this nematode is expelled by nonimmunoglobulin-bearing lymphocytes which are effective in the absence of newly formed cells derived from the cell recipients.