摘要:

SummaryThe cytotoxic reaction of normal peritoneal mouse cells, containing less than 3% eosinophils, against newbornTrichinella spiralislarvae, in the presence of antibody, was studied using newborn worms less than 2 h of age, or newborn worms that had been maintained in culture at 37°C for 20 h.Newborn worms 2 h old were killed, whereas 20 h newborn worms were not. The cells that initially adhered to the larvae were examined by electron microscopy. Only eosinophils adhered to 2 h newborn worms and only macrophages to 20 h ones. The attached eosinophils degranulated and died after a few hours. The macrophages that adhered to, but did not kill the 20 h newborn worms were morphologically in good state and no lysis of the larvae was observed.These results suggest that different antibody classes are involved in eosinophil and macrophage adherence, and strongly support the hypothesis that eosinophils mediate larval destruction. They also show that rapid changes are taking place after birth in the structure of the larval cuticle and that the age ofTrichinellanewborn worms is a major factor in the antibody‐dependent cellular cytotoxicity reacti

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1987.tb00508.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

SummaryThe capacity of peritoneal exudate cells (PEC) obtained from mice infected or immunized withPlasmodium bergheito produce reactive oxygen species (ROS) and the biological basis of this response was investigated, using luminol‐dependent zymosan‐triggered chemiluminescence (CL). CL response of PEC from infected mice increased at the early stage but was significantly depressed at the later course of the infection. A similar biphasic activity of peroxidase was also observed in PEC from infected mice. On the other hand, PEC from immunized mice exhibited concomitant increases of the ability to produce CL, the activity of peroxidase and the expression of Fc and C3receptors on cell surface. Compared with the controls, PEC from immunized mice showed an elevated background CL, responded more rapidly to the stimulation and generated considerably higher CL when triggered with opsonized zymosan. The data suggest that phagocytes in immunized mice are active in the production of ROS while those in infected mice are less active, and the inhibition of the ability of phagocytes to produce ROS may be one of the mechanisms for the parasites to escape from host immune sys

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1987.tb00509.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

SummaryStable human hybridomas were generated that produced inhibitory anti‐Plasmodium falciparummonoclonal antibodies. Peripheral blood lymphocytes, obtained from adults in Liberia, a malaria endemic area, were immortalized with Epstein‐Barr virus and then fused with KR4, a human, lymphoblastoid cell line. Stable hybridmoas that produced anti‐P. falciparummonoclonal antibody were identified by an ELISA assay that used the trophozoite and schizont antigens of both the Honduras I and FCR3 parasite strains. Monoclonal antibodies produced by selected hybridomas derived from lymphocytes of two individuals were subsequently studied. The anti‐parasite antibodies were produced at 1–3 μg/ ml in culture supernatants. All of the monoclonal antibodies bound specifically to trophozoites and schizonts of both strains of parasite in an indirect immunofluor‐escence assay and inhibited production of ring stage parasites by more than 90% when added to trophozoite or schizont containing erythrocytes in culture. Western immunoblot analysis of antigens obtained from trophozoites and schizonts (parasite age span of 36 to 48 h) was performed using either affinity purified or ammonium sulfate‐concentrated monoclonal antibody. Antibody from three hybridomas which bound primarily to antigens of the Honduras 1 strain had Mrof approximately 140000, 130

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1987.tb00510.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

SummaryMonoclonal antibodies (MoAbs) blocking transmission of malaria by blocking fertilization of female gametes by male gametes in the mosquito midgut immunoprecipitate three polypeptides (apparent non‐reduced mol. wt of 230000, 48000, 45000) from the surface of gametes and zygotes ofPlasmodium gallinaceumandP. falciparum.Earlier studies have shown that the epitopes with which the MoAbs react are present only on the mol. wt 230000 polypeptide inP. gallinaceumand the 48 000/45 000 mol. wt antigens inP. falciparum(Kumar 1985, Vermeulenet al.1985). In gel permeation chromatography all three polypeptides were found to be co‐eluted. Cross‐linking reagents were used to cross‐link proteins on the intact cells and in the soluble extracts. The cross‐linked product immunoprecipitated by the MoAbs showed an approximate mol. wt of 290000 to 300000, suggesting a stoichiometry of 1:1 between the high and low mol. wt polypeptides. Evidence was also obtained for the existence of a subpopulation of the 48 000/45 000 mol. wt polypeptides which is not complexed with the 230 000 mol. wt polypeptide. These data indicate that the 230 000 polypeptide is physically associated with the 48 000 and 45 000 polypeptides; the high and low molecular weight polypeptides appear to exist in a stable membrane boun

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1987.tb00511.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

SummaryThe salivary glands of ixodid ticks are complex organs which are known to contain the antigens responsible for tick resistance in animals. We have identified a large number of proteins from salivary gland extracts (SGE)*, at least some of which are immunologically recognized by tick resistant animals and which are therefore presumed to be secreted salivary components. During the 6 to 10 day feeding process, a number of these antigens alter in concentration according to individual kinetics, and some of these changes correlate with the kinetics of skin test reactivity of SGE obtained at different times throughout the feeding period. By use of immunoaffinity chromatography we have isolated large quantities of many of the salivary antigens (SGA) contained in SGE, and found that they contain several esterase activities. SGA stimulates both immediate and delayed skin reactions in tick resistant guinea‐pigs, and these reactions are about 200‐fold more intense, per unit protein, than those elicited by SGE. The skin reactions to SGA are basophil‐mediated and have many features in common with the cutaneous basophil hypersensitivity reactions of tick resistant animals. The demonstrated antigenic complexity of the glands may have profound implications for attempts to develop anti‐tick vaccines, as it may eventually be found that candidate vaccines will have to incorporate more than one tick antigen in order to be ef

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1987.tb00512.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

SummaryGoats infected withTrypanosoma congolensetransmitted byGlossina morsitans centralisand then treated with the trypanocidal drug diminazene aceturate are immune to tsetse‐transmitted infection with a homologous, but not heterologous trypanosome clone. Immune animals fail to develop localized skin reactions (chancres) and do not become infected, whereas on heterologous challenge chancres appear followed by parasitaemia. In this study, the feasibility of using chancre reactions to characterize several different metacyclic populations ofT. congolensewas evaluated. Provided goats were immunized, it was found that the chancre reaction could be used to distinguish different populations ofT. congolense.However, problems were encountered when attempts were made to induce immunity against more than one trypanosome population. When goats were infected by tsetse flies with four antigenically unrelated metacyclic populations ofT. congolense, either simultaneously or at 4 day intervals, adequate immunological priming was not always achieved. In fact, goats exposed to superinfection 8 to 12 days after a primary infection did not develop chancres or an immune response to the second infection (although they were immune to the organism used for primary infection). Following trypanocidal treatment these animals were subsequently completely susceptible to homologous infection with the metacyclic population used for superinfection, indicating that some form of interference phenomenon effective at the level of the skin appears to prevent or delay the development of the second trypanosome population following superinfection of infected animal

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1987.tb00513.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

SummaryA panel of monoclonal antibodies (MoAb) with specificities for bovine leucocyte subsets were used in conjunction with routine haematological procedures to analyse sequential changes in peripheral blood leucocyte populations during the course of tsetse fly‐transmittedTrypanosoma congolenseinfection in trypanotolerant N'Dama and trypanosusceptible Boran cattle. Subsequent to the first parasitaemic wave, the N'Dama cattle maintained packed cell volumes (PCV) above 22 and lower levels of parasitaemia than Boran throughout the 160 days of the experiment. In contrast, the Borans developed severe anaemia and required curative drug therapy (i. e., PCV dropped to less than 15) by 55 days (range: 22–55 days) post infection. There were significant (P<0±05) decreases in total white blood cells and total lymphocytes from pre‐infection levels to the first peak of parasitaemia (day 16 post‐infection) in both groups. Flow cytometric analyses using MoABs revealed that this change was due to an absolute decrease in T cells expressing BoT2 and either BoT4 or BoT8, surface immunoglobulin M‐positive (sIgM+) B cells, and null cells which did not express T cell, B cell or monocyte markers. During this period there was significant variation over time, but no overall increase or decrease, in the number of cells expressing class II major histocompatibility (MHC) molecules or monocyte markers, or in the number of circulating neutrophils or eosinophils. The BoT4/BoT8 ratios were significantly (P<0±01) increased in both groups of infected animals at the first peak of parasitaemia. After day 22 in the infected N'Damas and in the Borans which required drug therapy, there was a leucocytotic response characterized by an increase in the total number of B cells, T cells, and null cells. Prior to infection and throughout the course of the experiment N'Dama cattle had significantly (P<0±01) higher numbers of B cells and null cell

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1987.tb00514.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

SummaryThree inbred strains of mice, BALB/c, C57B1/6 and CBA J were infected with three clones ofTrypanosoma congolense, DIND/3–1, SAM 28±1 and KAR/57±1, which were obtained from three different stocks. DIND/3±1 was of high virulence for BALB/c and CBA/J but of negligible virulence for C57B1/6. SAM/28±1 was of high virulence and KAR/57±1 of negligible virulence for the three strains of mice. In each case, high virulence was correlated with a late, transient and low titre protective antibody response measured by complement mediated lysis of live organisms. Negligible virulence was correlated with an early, high titre protective antibody response. Suppression of the antibody response by sub‐lethal irradiation or cyclophosphamide treatment of the host turned a trypanosome infection of negligible virulence into one of high virulence. In mice with mixed infections it was shown that highly virulent trypanosomes did not influence the course of infection and antibody response to trypanosomes of negligible virulence and vice‐versa. The relationship of total antigen mass to the kineties of the antibody response suggests that 1000‐ to 10000‐fold less antigen is required in good responder than in bad responder mice to trigger the immune response. Thus the virulence ofT. congolensecan be determined by the antibody response of inbred strains of mice. The specificity and dose dependency of this antibody response seem to implicate the involve

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1987.tb00515.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

SummaryMetacyclic trypomastigotes ofTrypanosoma cruzi, derived either from triatomid vectors or axenic cultures, were found to be extensively lysed by sera of some non‐Chagasic healthy individuals through activation of the alternative complement pathway. Antibodies toT. cruzimetacyclics were detected by direct agglutination test in normal human sera (NHS) containing trypanolytic activity. Absorption of lytic NHS with metacyclic trypomastigotes, but not with non pathogenicHerpetomonas samuelpessoaipromastigotes, abolished the trypanolytic effect. Natural antibodies to trypomastigotes were not found in NHS devoid of trypanolytic activity. Precipitation of131I‐labelled metacyclic surface proteins with lytic NHS revealed as the major band a polypeptide with an apparent molecular weight of 75

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1987.tb00516.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1987.tb00517.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY