摘要:

SummaryThe effect of H2 and non‐H2 genes in a mouse model of protective immunity against Onchocerca lienalis microfilariae have been investigated. Non‐H2 effects were determined using CBA, BALB/c, B10, SJL and TO strains. All were permissive for establishment of a primary infection with microfilariae, although significant differences in parasite recoveries were evident amongst the various strains. The effect of H2 genes upon a primary infection was investigated using H2 congenic B10 and BALB strains, B10, B10.S, B10.BR, B10.D2/n, BALB/c, BALB.B, and BALB.K. Significant H2 effects were seen among the relatively weak responder B10 strains, but were not present among the relatively strong responder BALB strains. These results support a dominant effect of non‐H2 genes following primary exposure to microfilariae, and a ‘fine tuning’ effect of H2 genes that is apparent only in weaker responding strains. Upon reinfection of all the strains investigated, a gradation of protection was detected that appeared to be exclusively dependent

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1995.tb00899.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryWe have recently reported (Liu et al. 1995) that immunization of mice with recombinant 26kDa GST (reSjc26GST) induces a pronounced anti‐fecundity effect after experimental infection with Chinese Schistosoma japonicum. A similar vaccination trial was thus carried out on pigs, important reservoirs for schistosomiasis japonica, using purified, reSjc26GST and reSjp26GST from Schistosoma japonicum with alum as adjuvant; in general, similar results were obtained with the two sources of recombinant 26 kDa GST. Some protection in terms of worm reduction, significant with males, against challenge infection was observed in vaccinated pigs. Moreover, prior to challenge, levels of specific anti‐re26GST antibodies in the vaccinated pigs were significantly higher than in non‐vaccinated pigs as determined by GST‐ELISA. The most striking feature of the vaccine trial was the significant reduction in the number of eggs, especially mature eggs, in the livers of vaccinated animals. The results indicate that immunization with recombinant Sj26GST can provide some reduction in worm burden following exposure of pigs to reinfection with S. japonicum. In addition, reSj26GST can induce an anti‐fecundity effect, thereby reducing pathology, coupled with a delay or interruption of the development of immature to mature eggs in the liver. As a consequence, vaccination with SJ26GST would also prove useful in affecting the transmission of schistosomiasis

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1995.tb00900.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryImmunogens based upon sequences from the P. falciparum asexual blood stage antigen Pf332 were assessed for their capacity to induce antibodies inhibiting parasite growth or cytoadherence of infected erythrocytes in vitro. Selection of the Pf332 sequences was based on their reactivity with the human monoclonal antibody (MoAb) 33G2 which inhibits parasite growth as well as cytoadherence in vitro. Octameric multiple antigen peptides (MAP) were assembled based upon either a trimer of the minimal epitope recognized by the MoAb, VTEEI, or a Pf332 sequence including that motif, SVTEE1AEEDK. A dimer of SVTEEIAEEDK was also expressed in Escherichia coli, genetically fused to ZZ, two IgG‐binding domains of staphylococcal protein A. Rabbit antibodies elicited by the immunogens reacted with Pf332 in immunofluorescence and in ELISA with Pf332 peptides which were also recognized by MoAb 33G2. The MAP with branched (VTEEI)3peptide induced the highest litres of P. falci‐pamm‐reactive antibodies. In contrast to MoAb 33G2, none of the polyclonal Pf332 reactive sera cross‐reacted with repeat sequences of the malaria antigen Pf155jRESA. The polyclonal Pf332‐reactive antibodies inhibited parasite growth efficiently but had no or very low inhibitory effect in a cytoadherence assay. Thus, while Pf332 may be an important target for parasite neutralizing antibodies its involvement in cytoadherence i

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1995.tb00901.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryWe have investigated heat shock protein (HSP) expression in mouse‐virulent and ‐avirulent strains of Toxoplasma gondii by performing Western blot analysis using a monoclonal antibody against HSP65 of Mycobacterium bovis and a polyclonal antiserum against HSP70 o/Plasmodium falciparum as primary antibodies. We initially observed that murine macrophages express HSP65 when infected with either virulent or avirulent strains, a result which contradicts previous reports. Differential HSP expression consistent with virulence was observed between strains, with high levels of a 70kDa HSP (HSP70) only detected in virulent strains in vivo. This protein was not observed in virulent strains in the immunocompromised mouse or in vitro, suggesting induction by immunological stresses. This protein was only poorly expressed in avirulent strains. A 65 kDa protein was observed in all strains in vivo and in vitro, suggesting a shared epitope with HSP70. These results are consistent with the hypothesis that the induced expression of HSP70 in virulent strains of T. gondii by immunological stresses may provide protection for these strains against cell damage associated with invasion of the host, allowing the virulent strains to persist as tachyzoites without the requirement for the encystation observed in avirulent stra

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1995.tb00902.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryThe capacity of a recombinant glutathione S‐transferase from Schistosoma mansoni (rSm28GST) to vaccinate primates fErythrocebus patas,) against a heterologous infection with Schistosoma haematobium has been tested. Two injections of the purified molecule with Muramyl‐Di‐Peptide (MDP) as adjuvant resulted in a high level antibody response in the five immunized animals and in a significant reduction in worm fecundity compared to the controls which received adjuvant alone. Mean levels of daily egg excretion in urine and faeces were reduced by respectively 55% and 74% although perfusion revealed that worm burdens were similar in both groups. The protective effect was long lasting since it was maintained up to the end of the experiment, 42 weeks after infection. Hatching rates and the numbers of intra‐uterine eggs were also significantly affected by the vaccination. Tissue eggs were also drastically diminished in the urogenital system (–80%) but the reduction was not statistically significant. One animal was not protected by the immunization. There was a good correlation between parasitological data and the intensity of bladder lesions assessed by microscopic examination. Polypoid formations together with an intense exudation of the lamina propria were frequently seen in the controls but rarely in the vaccinated group where formation of scar tissue was predominant. These results underline the vaccine potential of the recombinant Sm28GST as a possible valuable prophylactic tool for the control of egg‐induced pathology and transmission of African s

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1995.tb00903.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryIsotypejsubclass‐specific antibody responses to adult Onchocerca volvulus extract (OvAg) were assessed by both ELISA and immunoblotting for a group of putatively immune individuals (PIs, n = 29) from a hyperendemic area in Ecuador and for a group of infected individuals (INFs, n = 47) from the same region. As a group, the Pis have been previously shown to possess lower levels of OvAg specific IgG1, IgG2, IgG3 and IgG4 than INFs but semiquantitative analysis revealed that the relative proportions of these subclasses differs between the two groups. The IgG of the PI group contained a higher proportion of IgG3 and a lower proportion of IgG4 than the INF group. The frequency distribution of IgG3 responses was similar for the PI and INF groups. The frequency distributions for IgG1, IgG4 and IgE were significantly different between the PI and INF groups. A subgroup of the Pis were identified from frequency distributions and multivariate plots of individual isotype responses as having antibody responses (mainly IgG4) possibly indicative of cryptic infection. High IgE responses were exclusive to INF individuals, and a rare response type of high IgG3 with negligible levels of other isotypes/subclasses was seen only in the PI group. However, the majority of the Pis had negligible responses for all antibody classes. Immunoblots demonstrated no obvious differences in qualitative recognition between the PIs and INF

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1995.tb00904.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryNatural killer (NK) and lymphokine activated killer (LAK) functions were measured in 40 patients with chronic Chagas disease divided into asymptomatic/indeterminate (18) and symptomatic forms (22) and in 24 healthy controls. A chromium release assay was used employing K562 or P815 cell lines as targets. There was no difference in either NK or LAK activity between the three groups. A small number of patients in each group showed results above or below the normal range for controls. However, there was no correlation between NK and LAK values in the same individual. In conclusion, NK and LAK functions do not seem to be involved in the immunosuppression associated with human chronic Chagas disease.

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1995.tb00905.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY