摘要:

SummaryInfective larvae ofBrugia pahangiwere injected subcutaneously into inbred PVG (‐RIT) rats, and ‘nude’ (PVG ‐rnu/rnu) (athymic) rats. Adult worms or circulating microfilariae were recovered from 20/34 (59%) of PVG ‐RTICrats and from 30/30 (100%) of ‘nude’ rats. Fertile worms were regularly found in the lumbar lymphatics and hearts of both strains of rat. Blood eosinophilia first developed in PVG ‐RTIcrats about 17 days, and in all such animals by 6 weeks. High circulating eosinophil counts persisted only in patent animals, proving a useful hallmark for the presence of microfilariae. Nude rats despite patency, developed eosinophilia only latterly and then to a lesser extent. Specific anti‐2?.pahangiIgG antibody was first detected at 7 days in all infected PVG ‐RTT rats, with levels rising until 8 weeks and remaining high only in microfilaraemic animals; total IgE showed a similar response. Specific IgE rose in all the eight patent rats inconsistently and only to low levels in eight non‐patent infected rats. IgG and IgE were undetectable in nude rats. Other strains of inbred rats of different RTI haplotype were also successfully infected withB. pahangiand the human parasiteB. malayi, a total of 10/23 (43%) and 5/15 (33%) becoming patent respectively. In the small numbers tested no major influence of RTI haplotype was detected. Infection by the intraperitoneal route did not result in the development of microfilariae. The difference in patency rates between ‘nude’ and normal PVG rats supports the contention that the development of filarial infections is T lymphocyte dependent. Inbred and ‘nude’ rats provide a valuable model of human filariasis, in which many features of filarial i

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1983.tb00769.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SummaryAgglutinins to uncoated culture forms of the African trypanosomes,T. congolenseandT.b. bruceiwere detected in sera from a variety of mammals not exposed to the parasites. The agglutinins in bovine serum were shown to be specific antibodies with opsonic properties selective for the species of trypano‐some. These findings suggest a possible role for the glycoprotein coat in preventing access of cross‐reacting antibodies to the plasma membrane of African trypanoso

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1983.tb00770.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SummaryRabbits were infected with two clones of antigenically distinct stocks ofTrypanosoma congolensetransmitted throughGlossina morsitans.Local skin reaction development and the appearance of neutralizing antibodies were followed in animals infected with one or other of the trypanosome stocks, with both stocks simultaneously or with both stocks consecutively. There was little difference in local skin reaction development on rabbits infected with a single stock or with both stocks simultaneously but, in rabbits exposed to a heterologous stock 14 or 21 days after a primary infection reactions were reduced in size or completely absent. Neutralizing antibodies against metacyclic‐derived trypano‐somes were detected 21 days after infection in animals infected with a single trypanosome stock and, in rabbits infected with both stocks simultaneously, antibodies against each stock were also detected 21 to 28 days after infection. In rabbits challenged 14 or 21 days after primary infection the appearance of trypanocidal antibodies against the stock used for challenge was delayed from 28 to 49 d

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1983.tb00771.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SummaryStriking differences in the resistance toP. chabaudiinfection among different inbred mouse strains have previously been correlated with the level of both the spontaneous and the infection‐induced enhanced level of NK cell activity. We have examined this putative correlation in individual animals of backcross progeny derived from A/J (malaria‐susceptible, low NK cell activity) and BIO‐A (malaria‐resistant, high NK cell activity) progenitors. We have found that NK cell activity and resistance to malaria segregated independently. Furthermore, C57BL/6‐bg/bg mice which are deficient in NK cell activity were found to be as resistant to malaria as their heterozygous C57BL/6‐bg/+ siblings. We conclude that low NK cell activity, characteristic of A/J strain mice, is not a sufficient determinant of the exquisite susceptibility of these animals to infection withPlasmodi

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1983.tb00772.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SummaryEleven strains of inbred mice were examined for their ability to develop resistance to challengeSchistosoma mansoniinfection as a result of previous exposure to homologous cercariae that had been attenuated by high‐dose irradiation. Two strains, C57B1/6J and BALB/c, demonstrated consistently high levels of vaccine‐induced immunity (means of 64% and 58% resistance, respectively, when compared to control groups of the same strain) and were designated as ‘high responder’ strains to vaccination. Six other strains fell into an intermediate category, demonstrating moderate, yet statistically significant, levels of immunity resulting from vaccination (means of 30–50% resistance). Only one of the strains examined consistently failed to respond to vaccination by the development of significant levels of immunity to challenge infection. Animals of the P/N strain demonstrated a mean of only 15% resistance to challenge in five experiments and have been classified as ‘low responders’ to vaccination. P/N mice have previously been characterized as deficient in their ability to mount delayed hypersensitivity reactions, produce lymphokine and display macrophage activation for cytolysis of extracellular and intracellular targets in other experimental systems, suggesting that these immune responses may be critical to the establishment of vaccine‐induced resistance toS. mansoniinfection. The availability of high and low responder mouse strains should facilitate a genetic approach to characterization of the immune effector mechanism(s) of vaccine‐induced resistance toS.

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1983.tb00773.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SummarySome aspects of the humoral response in trypanotolerant C57B1 mice and susceptible A/J mice were investigated to determine the possible basis of trypanotolerance. When the hepatic uptake of75Se‐labelledT. congolenseby infected mice was measured as an index of antibody production, it was found that only C57B1 mice could remove circulating labelled parasites, this ability persisting for several weeks after infection. Estimation of the immunoglobulin concentrations in both strains of mice showed that C57B1 mice developed a pronounced IgM response during the first parasitaemic wave, while A/J mice did not. Over the same period the IgM concentrations in C57B1 mice initially fell, but recovered at the time of peak parasitaemia. In contrast, A/J mice showed a continual fall in total IgG concentrations in the circulation until death 10 days after infection. Finally, it was shown that during the initial rising parasitaemia, the plaque forming cell responses of both strains of mice to sheep red blood cells were normal indicating that neither strain of mice was immunosuppressed. Also, A/J mice vaccinated with irradiatedT. bruceion day 4 and C57B1 mice vaccinated either on day 4 or day 60 of aT. congolenseinfection were able to mount an effective immune response to the vaccine, as judged by the hepatic uptake of radiolabeled parasites. All of the results indicate that the trypanotolerance of C57B1 mice depends, at least in part, on their more efficient antibody respons

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1983.tb00774.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SummaryF. hepaticainfection of rats caused a prolonged elevation of serum total IgE reflecting the continued presence of live worms in the host. Infection with 40 metacercariae stimulated higher total IgE levels than infection with 20 metacer‐cariae. The parasite specific IgE response was biphasic, the first peak coinciding with the migratory phase in the liver parenchyma and the second with the establishment of flukes in the bile duct

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1983.tb00775.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1983.tb00776.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY