Further studies on resistance to reinfection with Schistosoma japonicum in mice.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
G F Mitchell
Publications and source records attributed to G F Mitchell.
Anti-worm antibody specificities in 129/J mice resistant to infection with Schistosoma japonicum.
Explore the source record for details and available documents.
Animals↗
Babesia bovis: proteins of virulent and avirulent parasites passaged through ticks and splenectomized or intact calves.
Passage of the avirulent vaccine (K) strain of Babesia bovis (KA) through either Boophilus microplus ticks, intact calves, or intact calves and then ticks, resulted in two distinct protein and protein antigen profiles as analyzed by two-dimensional gel electrophoresis of biosynthetically labeled proteins and immunoprecipitates. Different degrees of expression of two major acidic antigens of KA designated Ka1 (Mr 47,500) and Ka2 (Mr 43,000) were observed. Ka1 was apparently lost following passage of KA B. bovis through intact calves but was strongly represented in the parasite population following a single tick passage. In contrast, passage through ticks of the virulent KV B. bovis (from which KA was derived by passage in splenectomized calves) did not lead to strong representation of the Ka1 protein although there was increased representation of another major acidic protein antigen, designated KV (Mr 35,000). These data suggest that the previously recognized reversion to a strain-dependent basal antigenic type in the tick vector depends also on intrastrain characteristics such as virulence and strain heterogeneity. The data suggest that KA is a more heterogeneous population than KV although cloned isolates are required to establish this point. Comparable syringe passage of another strain of B. bovis, designated C strain, through splenectomized calves resulted in less marked differences between the putative CA and CV B. bovis. This may explain the less stable avirulence of CA compared to KA B. bovis. Various selection pressures must act, in either the tick or the vertebrate host, on subpopulations in heterogeneous isolates to produce the changes described in protein antigen profiles of B. bovis. The possible relevance of changes in representation of proteins to biological characteristics of B. bovis (such as virulence and tick transmissibility) is discussed.
Animals↗
Taenia taeniaeformis: immunoprecipitation analysis of the protein antigens of oncospheres and larvae.
Biosynthetically or exogenously labeled proteins and immunoprecipitated protein antigens of established 28-day-old larvae of Taenia taeniaeformis were compared with proteins and antigens of infective oncospheres using single and two-dimensional gel electrophoresis. Immunoprecipitation was carried out using sera from infected mice and mouse antisera raised to larvae or oncospheres, and emphasis was placed on identifying antigens common to both oncospheres and larvae. Two major larval antigens of Mr 40,000 and 200,000, designated Tt40 and Tt200, are common to somatic larval preparations and oncospheres. Additionally, two major oncosphere antigens of Mr 55,000 and 60,000, designated Tt55 and Tt60, are also present in larval excretory and secretory (i.e., ES or exoantigen) products. Information obtained from these immunoprecipitation analyses will facilitate isolation and production of common as well as stage-specific protein antigens in the development of defined-antigen vaccines in this model system of cysticercosis.
Animals↗
Isolation and characterization of infective and non-infective clones of Leishmania tropica.
Cloning by limit dilution of an isolate of Leishmania tropica (LRC-L137) that is infective for mice resulted in 7 stable clones, only one of which was infective in BALB/c mice. Three of the non-infective clones that were examined for survival in BALB/c macrophages in vitro seemed to be killed more readily, suggesting failure to establish in macrophages as the basis for non-infectivity in vivo. Promastigotes from three non-infective clones and one infective clone were biosynthetically labelled or surface radioiodinated, and the detergent lysates were analyzed by 2-dimensional gel electrophoresis. The pattern of the radiolabelled cytoplasmic and membrane proteins of promastigotes from all L. tropica clones was similar, with minor differences. All clones as well as the uncloned population bound to the same extent to a series of lectins with galactose and N-acetylgalactosamine as specificities. They also bound in a solid-phase radioimmunoassay to 9 monoclonal antibodies raised against the uncloned L. tropica (LRC-L137). The genetic characterization of four L. tropica clones was attempted by analysis of their isolated kinetoplast DNA. The clones from two schizodemes since they possess kinetoplast DNAs which exhibit similar restriction endonuclease fingerprints and show extensive DNA sequence homology, suggesting that the four clones are closely related and that the non-infective variants may be derived from the infective presumptive parental clone L137-7-121. Further characterization of the clones of L. tropica should allow a better understanding of the genetic basis of parasite virulence in cutaneous leishmaniasis.
Animals↗
Infections with a Malaysian dog strain of Ancylostoma ceylanicum in outbred, inbred and immunocompromised mice.
The course of infection with a Malaysian dog strain of Ancylostoma ceylanicum was investigated in 15 inbred strains of mice, in outbred and inbred mice immunosuppressed with prednisolone, and in immunodeficient hypothymic mice. Oral, percutaneous and subcutaneous routes of infection, in both sexes of mice, were assessed. In only one instance was a single small adult male worm found. Following oral infection, larvae migrated from the stomach to the large bowel and then a proportion of worms penetrated the perianal skin. This was followed by the appearance of larvae in the lungs. Living 3rd-stage larvae were seen in the anterior small intestine, perianal skin and lungs for the 6 weeks of the study, with peak recoveries being at 12 h, 8 days and 3 weeks, respectively. It is clear that systemic migration of larvae occurs after oral infection, and it is possible that recirculation may occur. Only a small percentage of larvae penetrated the abdominal skin after being administered percutaneously. In subcutaneous infections, a small proportion of larvae moved rapidly from the site of injection and were recovered from the lungs 2 h after infection. Most larvae, however, migrated from the injection site over the ensuing few days. Living 3rd-stage larvae were seen in the lungs and in the small intestine for the 4 weeks of observation. The strain of A. ceylanicum employed does not complete its development in mice. Nevertheless, this model offers significant potential for studying the immune responses, as well as investigating the means by which these parasites evade host defences.
Ancylostoma↗
Leishmania tropica major in mice: vaccination against cutaneous leishmaniasis in mice of high genetic susceptibility.
BALB/c and BALB/c.H-2b mice are genetically susceptible to development of persistent and severe disease following cutaneous injection of promastigotes of the protozoan parasite, Leishmania tropica major, whereas C57BL/6 are relatively resistant. Resistance in C57BL/6 can be further increased by intraperitoneal injection of living, but not killed, promastigotes prior to cutaneous challenge. Severely diseased BALB/c mice can show resistance to development of a second cutaneous lesion but apparently only in the advanced stages of systemic life-threatening disease. A striking level of resistance to persistent disease has been demonstrated in BALB/c.H-2b mice pre-injected with frozen and thawed L. t. major-infected macrophages of the continuous macrophage cell line IC-21 (H-2b) together with Corynebacterium parvum. No resistance is seen in recipients of either C. parvum or the crude antigen mixture alone. Protection is afforded by intraperitoneal and not subcutaneous injection of crude antigen plus adjuvant. In these vaccination studies all evidence points to the infected macrophage as most appropriate source of 'host-protective' antigens as well as being the most likely target of host-protective immunity. Resistance is expressed in vaccinated mice as minimal signs of cutaneous disease and rapid resolution of any small lesions which do develop. Frozen and thawed promastigotes plus C. parvum will not induce resistance to persistent disease in BALB/c.H-2b mice and preincubation of promastigotes with sera from resistant vaccinated mice does not influence their capacity to cause cutaneous disease. The results provide baseline data for vaccination attempts in genetically susceptible hosts using isolated L. t. major antigens (and, in particular, infected macrophage antigens) and highlight the utility of the intraperitoneal route of injection and the use of the therapeutic biological, C. parvum, as an adjuvant in such studies.
Animals↗
Competitive radioimmunoassays using hybridoma and anti-idiotype antibodies in identification of antibody responses to, and antigens of, Schistosoma japonicum.
A hybridoma-derived monoclonal antibody, I.134, with apparent specificity for Schistosoma japonicum adult worms has immunodiagnostic potential for schistosomiasis japonica in the Philippines. Sera from known infected individuals will inhibit the binding of 125I-labelled I.134 to a crude adult worm extract (AWE) in a competitive radioimmunoassay (CRIA), although a 10% false negative rate has been noted. Another monoclonal antibody, P.41, which produces circumoval precipitation (COP) reactions with S. japonicum eggs was shown previously not to be useful in identification of heavily infected individuals using a CRIA with extracted egg antigens (EA). However, the 125I-P.41/EA assay has now been demonstrated to be capable of detecting a small subset of infected persons. Thus, four infected individuals with serum COP reactions shown to be consistently of the bleb type only (and with no segmented precipitates seen in the optimized COP test) have serum inhibitory activity in the P.41 CRIA. These same sera are negative in the I.134 CRIA. Unsuccessful attempts have been made to substitute a large pool of affinity-purified anti-I.134 idiotypic (Id) antibodies for antigen (i.e. AWE) in the immunodiagnostic I.134 CRIA. However, anti-Id CRIAs have been shown to be useful in monitoring the isolation of target antigens of hybridoma anti-schistosome antibodies. The availability of a range of hybridoma antibody-based CRIAs will greatly facilitate the quantitative analysis of anti-S. japonicum antibody specificities in sera from clinically defined patient groups and the isolation of antigens of immunoparasitological interest.
Animals↗
Attempts to modify lung granulomatous responses to Schistosoma japonicum eggs in low and high responder mouse strains.
A radioisotopic assay for acute granulomatous hypersensitivity (AGH) to lyophilized eggs of Schistosoma japonicum has been used to further examine responses to egg antigens in various inbred strains of mice. The ranking of responsiveness in mice from high (C57BL/6), intermediate (BALB/c) to low (CBA/H) was not influenced by high or low egg-sensitization regimens. However, the low responsiveness of responder mice sensitized with eggs by the intraperitoneal compared with the subcutaneous route of injection appears to be an egg dose-related phenomenon. The high AGH responsiveness of C57BL/6 mice can be increased further by sensitization with eggs in the presence of purified pertussigen from Bordetella pertussis but CBA/H mice treated identically remain low responders. The monoclonal anti-egg antibody, P.41, which produces a prominent bleb-type circumoval precipitate with eggs, has been shown to be directed against major 'immunopathologic antigen(s)' of S. japonicum eggs. Thus, C57BL/6 mice were sensitized for AGH by injection of soluble extracted egg antigen (SEA) bound to an immunoabsorbent of P.41 antibody on Sepharose. No success has been achieved in modulating AGH in C57BL/6 mice by injection of hyperimmune antisera raised against lyophilized eggs in either high or low responder mouse strains. This failure is in line with previous results using antisera as well as monoclonal anti-egg antibodies. The consistent failure to demonstrate a modulating effect of antibodies in this compared with other laboratories may be related to the use of lyophilized rather than viable eggs. The data suggest that activities of antisera in granuloma modulation in murine schistosomiasis japonica result from egg destruction or inhibition of production of immunopathologic antigens by eggs rather than through effects on immunopathologic immune responses.
Animals↗
Vaccination of genetically susceptible mice against chronic infection with Nematospiroides dubius using pertussigen as adjuvant.
The intestinal nematode Nematospiroides dubius persists for prolonged periods in mice after a single oral administration of infective larvae. After multiple administrations of larvae, some inbred mouse strains (termed 'resistant') develop the capacity to expel the majority of adult worms from the intestines. Other mouse strains such as CBA/H and C57BL/6 (and, in particular, males) are far more susceptible in that they expel few, if any, adult worms after repeated doses of larvae and may die with high worm burdens. One means to accelerate rejection of adult worms in a primary infection is to presensitize mice with a small number of living adult worms injected intraperitoneally. However, an impressive vaccination effect of ectopically implanted worms has only been demonstrated to date in resistant mouse strains. In this paper, success has been achieved in vaccinating genetically susceptible mice against chronic primary infection with N. dubius. Young male specific pathogen-free (SPF)-derived C57BL/6 mice demonstrate greater than 90% resistance after injection of adult worms but only when further injected with pertussigen from Bordetella pertussis as adjuvant. Accelerated rejection of adult worms appears to be the principal manifestation of resistance in vaccinated mice. A high degree of protection has also been obtained in recipients of pertussigen plus the supernatant of a crude worm extract equivalent to less than 10 adult worms per mouse. Although no information is available on the effector mechanisms responsible for worm rejection in vaccinated mice, pertussigen is known to increase both immediate and delayed type hypersensitivity responses and to increase tissue sensitivity to histamine. A strategy which sensitizes recipients such that a subsequent challenge infection is not sustained, and which is effective in highly susceptible hosts, opens the way to vaccination against chronic intestinal infections in those hosts most in need of protection.
Adjuvants, Immunologic↗
An examination of differences in serum antibody specificities and hypersensitivity reactions as contributing factors to chronic infection with the intestinal protozoan parasite, Giardia muris, in mice.
After oral administration of cysts of the intestinal protozoan parasite, Giardia muris, young male C3H/He mice are chronically infected, whereas BALB/c mice demonstrate a rapidly resolving pattern of infection. Both strains of mice injected with trophozoites in adjuvant and challenged orally with cysts develop serum antibodies to numerous trophozoite proteins. A limited number of these protein antigens was differentially immunoprecipitated by sera from resistant BALB/c and susceptible C3H/He mice exposed to G. muris. 35S-methionine-labelled protein antigens better recognized by immune BALB/c sera included molecules of relative mobility (Mr) 82,000 and a series of proteins of Mr 25,000 to 32,000. Differential recognition extended to a subset of solubilized trophozoite antigens that bind to the lectin, wheat germ agglutinin (WGA), and that can be radio-iodinated. In particular, a complex of 4 acidic protein antigens of approximate Mr 32,000, and designated collectively as Gm32, was better recognized by immune BALB/c serum than C3H/He serum. Isolated WGA-binding antigens were not able to consistently vaccinate BALB/c mice against subsequent G. muris infection. Moreover, preliminary evidence has been obtained that lack of antibody responsiveness to Gm32 does not segregate strictly with susceptibility to chronic infection in (BALB/c X C3H/He)F2 mice. These data, plus the observation that drug-cured C3H/He mice are highly resistant to reinfection, has led to examination of whether mice differ in the capacity of the intestines to support inflammatory responses. Mast cell deficient Wf/Wf mice, unlike wild-type litter-mates, developed chronic giardiasis although no reconstitution of resistance has yet been achieved with inocula of bone marrow cells from +/+ mice. BALB/c mice injected with the antihistamine and antiserotonin drug, cyproheptadine, also showed prolonged infections with G. muris. The data suggest that analysis of specificity differences in immune responses of mice varying in susceptibility to intestinal parasites must be supplemented by examination of the capacity of the intestine to support induced immune responses.
Animals↗
Sj23, the target antigen in Schistosoma japonicum adult worms of an immunodiagnostic hybridoma antibody.
An IgG2a mouse hybridoma-derived antibody (designated I.134) has been identified which binds to Schistosoma japonicum adult worms and which has immunodiagnostic potential (for detection of antibody) in schistosomiasis japonica in the Philippines. The target epitope of this hybridoma antibody is contained in a 23 000 molecular weight protein of adult worms as analysed by one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis of immunoprecipitates and a gel overlay technique. This adult worm antigen has been labelled biosynthetically using 35S-methionine as well as exogenously using lactoperoxidase-catalysed radioiodination and the Bolton and Hunter reagent with intact worms. As anticipated, the low molecular weight protein antigen (designated Sj23) appears to be one of several major immunogenic proteins of worms which induce antibodies in infected Philippine patients.
Animals↗
Murine cutaneous leishmaniasis: resistance in reconstituted nude mice and several F1 hybrids infected with Leishmania tropica major.
After cutaneous injection of promastigotes of an isolate of the intramacrophage protozoan parasite, Leishmania tropica major, mouse strains develop chronic cutaneous lesions or show a resolving pattern of disease. On this basis, they can be classified as resistant (e.g. CBA/H and C57BL/6) or susceptible (e.g. BALB/c, BALB/c.H-2b and BALB/c.H-2k). Hypothymic nude (nu/nu) mice of either BALB/c, CBA/H or C57BL/6 genotype are susceptible to chronic disease. However, nude mice of these genotypes, including BALB/c, are resistant to chronic cutaneous leishmaniasis when injected at the time of parasite challenge with small numbers of H-2 compatible lymphoid cells from normal mice. Nude mice remain susceptible when injected with fully H-2 incompatible cells. Using cells from H-2 mutant mice for reconstitution of resistance in C57BL/6.nu/nu mice, evidence was obtained that I region compatibility is necessary for cells to mediate host-protective effects. Cells from chronically-diseased BALB/c mice do not have protective effects in BALB/c.nu/nu mice at any cell dose and will abrogate the resistance-promoting effect of normal BALB/c lymphoid cells in such mice. In contrast, protective effects of lymphoid cell populations from chronically-diseased BALB/c.H-2k and BALB/c.H-2b mice can be demonstrated when assayed at certain cell doses in H-2 compatible CBS/H.nu/nu and C57BL/6.nu/nu mice, respectively. The data suggest that chronically-diseased (genetically-susceptible) mice contain a mixture of resistance-promoting and disease-promoting T cells in their peripheral lymphoid organs and that expression of the resistance-promoting subset can occur in nude mice of resistant genotype. Previous data have indicated that Ly1+2- T cells are efficient mediators of both T cell-dependent activities. No evidence for the operation of disease-promoting or resistant-promoting antibodies in perpetuation or resolution of disease has been obtained in extensive serum transfer experiments. Some discrepancies exist in the literature on the question of the dominance of susceptibility or resistance in F1 hybrid mice. A re-examination of susceptibility/resistance in F1 hybrids between BALB/c and several other parental strains was undertaken using cloned pathogenic promastigotes derived from a heterogeneous L. t. major isolate in order to reduce effects of parasite heterogeneity in the analysis. Resistance was dominant in some but not all F1 hybrids, with most showing a delayed healing pattern of disease relative to the resistant parental strain. Despite the use of genetically-homogeneous parasites, the analysis was complicated by variability within groups of F1 hybrid mice as well as between males and females and between F1 hybrids of reciprocal crosses.(ABSTRACT TRUNCATED AT 400 WORDS)
Animals↗
Hybridoma antibody-based competitive ELISA in Schistosoma japonicum infection.
A competitive enzyme-linked immunosorbent assay (ELISA) has been developed and compared with the circumoval precipitin test (COPT) for diagnosis of schistosomiasis japonica using Philippine sera. The assay is based on the inhibition, by sera, of the binding of a penicillinase-conjugated hybridoma-derived antibody, I. 134, to a crude Schistosoma japonicum adult worm extract. A change in pH subsequent to addition of the substrate is used as the indicator system. Development of the color change in this assay is relatively slow, a fact which presumably facilitates detection of inhibition by serum. Relative to the COPT, no false positive reactions were obtained and the false negative rate was less than 10%. A wide range of inhibitory titers was obtained using sera in the competitive ELISA similar to that found in a competitive radioimmunoassay using 125I-labeled I. 134. The competitive ELISA will be of more general application for diagnosis of schistosomiasis japonica than the competitive RIA using hybridoma antibodies, and will provide more precise quantitative information than is obtainable in the COPT.
Antibodies↗
Resistance to reinfection with Schistosoma japonicum in the mouse.
BALB/c and outbred mice infected with a Philippine isolate of Schistosoma japonicum for 50 to 60 days expressed strong resistance to reinfection. The extent of this reinfection resistance ranged from 72 to 93% in 5 experiments (mean = 80% resistance) as determined by numbers of immature worms recovered from already infected and age- and sex-matched challenge control mice exposed 20 days previously to cercariae. Determination of numbers of recoverable worms from (the initial) infection suggest that adult worms are lost progressively during the period in which impressive resistance to reinfection is demonstrable. An important unresolved question is whether loss of adult worms is related in any way to expression of resistance to reinfection. Some indirect evidence indicates that the major component of reinfection resistance is expressed prior to day 4 of challenge infection. This evidence derives from analysis of lung petechiae which, in a primary infection, have been shown to provide an indication of number of adult worms which can be detected subsequently (e.g. at 30-40 days of infection). Although anti-parasite immune response have not yet been shown to be responsible for this apparent concomitant immunity, the magnitude of resistance to reinfection in the S. japonicum/mouse system should facilitate identification of any immunological effector mechanisms involved.
Animals↗
Innate resistance to Schistosoma japonicum in a proportion of 129/J mice.
Explore the source record for details and available documents.
Animals↗
Reduce embryonation of Schistosoma japonicum eggs as a contributory mechanism in modulation of granuloma in chronically sensitized mice.
Explore the source record for details and available documents.
Animals↗
Target antigens of purified human immunoglobulins which inhibit growth of Plasmodium falciparum in vitro.
Explore the source record for details and available documents.
Adult↗