摘要:

SummaryCon A‐pretreated mononuclear (MNC) cells from Thai adults with naturally acquired P. falciparum or P. vivax malaria were significantly less effective in suppressing the responsiveness of autologous or normal allogeneic responder cells to mitogenic lectins or allogenic stimulator cells than pretreated cells from healthy donors. Serial studies of three patients demonstrated that reduced suppressor cell activity was present early in malaria infection but returned to normal soon after treatment. These studies demonstrate that the loss of T cells previously observed in patients with malaria, in part may functionally represent a loss of suppressor T cell

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1983.tb00758.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SummaryThe peripheral blood mononuclear cell (PBMN) proliferative responses of cells from patients with schistosomiasis were studied in the presence and absence of indomethacin in the culture medium. PBMN cultures were exposed to antigenic extracts of either adult S. mansoni worms (SWAP) or cercariae (CAP), and assayed for the incorporation of tritiated thymidine. More than 70% of the 48 patients studied with SWAP and the 40 patients studied with CAP, were not substantially effected by the addition of indomethacin to the cultures. The remainder (less than 30%) was augmented more than 50% by indomethacin and comprise a group which gave initially low responses to these antigenic preparations. Further analysis indicated that in some schistosomal patients the effect of an adherent suppressor cell population may, in part, be based on a prostaglandin‐mediated, indomethacin‐sensitive suppressive mechanism. However, the majority of patients, most of whom display adherent suppressor cells, are unaffected by indomethacin. Apparently, other adherent cell suppressor mechanisms are responsible for the regulation obser

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1983.tb00759.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SummaryOn a B10 (Lshs) genetic background, the development of acquired T cell mediated immunity to Leishmania donovani infection in mice is under H‐2 linked genetic control. Following intravenous inoculation of 107amastigotes three phenotypic patterns of recovery have been described: ‘early cure’ (H‐2r,s), ‘cure’ (H‐2b) and ‘non‐cure’ (H‐2d,q,f). In an attempt to determine the immunological basis for this H‐2 linked genetic control the effects of varying parasite dose (5 × 103to 5 × 107amastigotes) and of pre‐treatments with cyclophosphamide (50 or 200 mg/kgbody weight CY) or sublethal irradiation (100 or 550 rad) on the course of infection, and on circulating anti‐leishmanial IgG levels, were examined in strains representative of the three phenotypes: B10.D2/n (H‐2d), C57BL/10ScSn (H‐2b) and B10.RIII (H‐2r). It was found that with low parasite doses (5 × 103or 5 × 104) ‘non‐cure’ mice presented a ‘cure’ profile whilst raising the dose (5 × 107) caused some perturbation of the normal self‐curing response in ‘cure’ (but not ‘early cure’) mice. The highest dose did not, however, lead to progressive disease in the genetically non‐cure strain. For the parasite dose experiments circulating anti‐leishmanial IgG levels were higher in the early cure and cure strains than in the H‐2dnon‐cure strain. The higher doses of CY and sublethal irradiation administered prior to infection had a clear prophylactic effect on the non‐cure strain with some effect also observed in cure and early cure strains. This was thought to be due to deletion of the precursors of T suppressor (Ts) cells suppressing cell‐mediated immunity. Resolution of the liver parasite load in pre‐treated mice took place despite minimal or undetectable levels of circulating anti‐leishmanial IgG. Similarly, the earlier resolution of parasite load in pre‐treated cure and early cure mice occurred even though the antibody response was severely reduced. This suggests that the high antibody responses observed in early cure and cure strains do not normally mediate cure and may simply reflect

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1983.tb00760.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SummaryWhile Trypanosoma brucei brucei GUTat 3 were equally infective for C3H/Heand for C57B1/6 mice at doses ranging from 5 to 5 × 103organisms and had similar prepatent periods in both strains of mice, infected C57B1/6 mice displayed lower parasitaemia, shorter times to parasite wave remission and survived for a longer time than infected C3H/He mice. Parasite growth and differentiation rates and host immune responses were similar for the first 5 days in both strains of mice after infection with 103T.b.brucei GUTat 3 but, thereafter, parasite differentiation proceeded more rapidly and specific antibodies reached higher titres in C57B1/6 than in C3H/He mice. In contrast, parasite growth and differentiation rates were similar in irradiated mice of both strains. Furthermore, following inoculation of intact mice with irradiated T.b.brucei GUTat 3, C3H/Hemice actually mounted higher titred antibody responses than C57B1/6 mice showing that they were not intrinsically defective in their capacity to respond to GUTat 3 antigens. Parasite differentiation occurred at the same rate in irradiated (650r) C57B1/6 mice and in irradiated C57B1/6 mice reconstituted with syngeneic spleen cells although T.b.brucei GUTat 3 specific antibody was detected in the latter mice prior to peak parasitaemia. Furthermore, it was shown directly in C57B1/6 mice that there was no selective destruction of slender form T.b.brucei GUTat 3 parasites during the phase of accumulation of stumpy form parasites. These studies indicate that the more rapid differentiation of T.b.brucei GUTat 3 parasites in infected C57B1/6 mice as compared to infected C3H/Hemice was unlikely to be directly related to the more efficient antibody response in the infected C57B1/6 mice. The observations suggest that there might be an association between host mechanisms which regulate differentiation of T.b.brucei parasites and those which regulate antibody responses

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1983.tb00761.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SummaryThe ELISA test was used for the detection of antibodies to coccidia in the serum and/or egg yolk of chickens infected with Eimeria acervulina, E. maxima or E. tenella and in the serum of rats infected with E. nieschulzi. Antigens prepared from different developmental stages of the parasite were tested and the cross‐reaction between different species of Eimeria were examined. The variability in cross‐reactivity of different species and the advantages and possible applications of the test are discus

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1983.tb00762.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SummaryAn in vitro culture Trypanosoma congolense cell line was established using the mammalian cell feeder layer system. One of the principle characteristics of this parasite was its ability to multiply in culture at 35°C, as an uncoated trypanosome (lacking a glycoprotein surface coat) unlike the original blood stream form from which it was derived. This trypanosome was lysed when incubated in normal human serum in contrast to the parasite which possessed a surface coat. The lytic reaction was inhibited by EDTA but not EGTA and occurred in C2‐deficient serum, demonstrating the involvement of the alternative pathway of complement activation. Similar results were obtained with procyclic forms of T. congolense and T. brucei brucei which also lacked surface coats. The results suggest that the glycoprotein surface coat protects the parasite by masking sites on the plasma membrane which are capable of promoting alternative pathway activati

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1983.tb00763.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SummaryLevels of antibody a binding to the schistosomulum surface and b mediating in vitro eosinophil‐dependent cytotoxicity of schistosomula were studied and compared to the in vivo levels of resistance to cercarial challenge in mice infected with irradiated cercariae, unirradiated cercariae of single or mixed sex, or injected with eggs. Antibody‐binding was assessed by counting the number of IgG‐Fc‐receptor bearing cells (P388D1cells) adhering to mechanically‐transformed schistosomula. Significant levels of adherence occurred with sera taken from 1–2 weeks following exposure to irradiated cercariae, the level increasing gradually thereafter and being enhanced by repeated exposure. Sera from the bisexual infection showed a dramatic increase in binding activity between weeks 5–8, and with the single sex infections there was a steady rise up to week 10 followed by a sharp rise between weeks 10–12. Weekly injections of eggs produced a steady rise in serum binding activity. Sera taken just before challenge were also tested for their ability to mediate killing of schistosomula by eosinophil‐enriched preparations of heterologous rat peritoneal exudate cells in vitro. Significant levels of killing occurred with all sera, but the greatest lethal activity was found in sera from the egg‐injected, chronically‐infected and 200 male cercariae‐infected groups. This ranking did not correlate with in vivo resistance against challenge as assessed by worm recovery, the egg‐injected and single sex‐infected groups failing to mani

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1983.tb00764.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SummaryMycobacterium lepraemurium (MLM) infection increases the sensitivity of mice to lipopolysaccharide (LPS) as do infections with other intracellular parasites. Tumour necrosis factor (TNF), lymphocyte activating factor (LAF) and increased levels of various lysosomal and cytoplasmic enzymes were found in serum samples taken 2 h after intravenous injection of a small dose of LPS suggesting that damage to a variety of cell types, including macrophages, had occurred. Sera from moribund MLM‐infected mice not injected with LPS also demonstrated significant levels of TNF compared with controls. Intravenous injections of silica into leprous mice also led to increased levels of serum lysosomal and cytoplasmic enzymes but did not give rise to a significant amount of TNF or LAF. Moreover, in contrast to LPS treatment, the injection of silica did not lead to the death of leprous mice. These findings suggest that the phagocytic cells of the infected animals did not contribute to the production of these mediators after LPS challenge. Rather, the non‐phagocytic granuloma macrophages or other unidentified cell types seemed to provide the main source of the monokines TNF and LAF in vivo in the present model. These mediators may have important implications for the immunopathology of MLM infect

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1983.tb00765.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SummaryInfective larvae of Brugia pahangi were 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?. pahangi IgG 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 with B. pahangi and the human parasite B. 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.tb00766.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. congolense and T.b. brucei were 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.tb00767.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY