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D Wakelin

Publications and source records attributed to D Wakelin.

At least 127 records · Page 7Linked to original sources
PubMed1989

Kinetics of Nippostrongylus brasiliensis infection in the zinc-deficient rat.

The role of zinc (Zn) in the immunological expulsion of the nematode Nippostrongylus brasiliensis (Nb) from the small intestine of the rat was investigated. Three groups of 28 rats each were fed a basal diet providing either 3 mg Zn/kg for the zinc-deficient group (-Zn) or 40 mg Zn/kg for ad libitum-fed and pair-fed controls. After 6 wk each group was divided into two equal subgroups and infected with either 1000 or 4000 infective Nb larvae/rat. The -Zn rats showed significant reductions (P less than 0.001) in food intake, weight gain and food conversion efficiency when compared to the rats fed ad libitum but not when compared to the pair-fed controls. Plasma zinc concentration in the -Zn rats (0.50 microgram/ml) was significantly lower than in both ad libitum-fed (1.33 micrograms/ml) and pair-fed (1.45 micrograms/ml) controls (P less than 0.001). The recovery of worms from the rats 3, 7 and 12 d postinfection was similar for the corresponding day and dose of infection in all groups. Expulsion was almost complete in all groups by 12 d post-infection. There were no significant differences in size and fecundity of worms recovered from the different groups of rats on 7 d postinfection. However, over the whole period of infection, the -Zn rats excreted significantly more parasite eggs than did controls (P less than 0.001). These results indicate that although zinc deficiency affected growth performance of the rats, it did not affect the establishment or expulsion of Nb. Impairment of the immune response of the zinc-deficient rat was manifested only by a significant increase in the number of parasite eggs excreted in feces.

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PubMed1989

Genetic variation in the humoral immune responses of mice to the nematode Trichuris muris.

Genetically based differences in the antibody responses to the large intestinal nematode Trichuris muris were studied in two groups of H-2 congenic strains of mice that differed in their relative resistance to infection with this parasite. The primary antibody response to parasite excretory/secretory (E/S) antigen was predominantly an IgG response with the strains forming two distinct groups, defined by their genetic background. The more susceptible B10 genetic background mice had strikingly higher antibody levels than mice of the BALB genetic background. Superimposed upon these background effects were clearly defined influences attributable to H-2-linked genes, strains which differed genetically only at H-2 loci exhibiting differences in the kinetics of the antibody response. Only B10.G and B10.BR mice showed any great increase in IgM levels post-infection. No IgA specific to E/S antigen was detected in the peripheral circulation of any strain at any time post-infection. Antibody responses to a 40-43 kD antigen revealed clear H-2-linked gene effects, with mice sharing the H-2k haplotype (B10.BR, BALB/K) exhibiting considerably higher total antibody levels than strains expressing other haplotypes; mice of the H-2d haplotype (BALB/c, B10.D2/n) responded very weakly to this antigen. A Western blot analysis of antigen recognition by antibody revealed similarities between the mouse strains in their total antibody responses to T. muris E/S antigen. However, immunoprecipitation studies showed that in general the more susceptible B10 congenic strains had wider spectra of antigen recognition than the BALB congenics. Strains sharing the same H-2 haplotype had dissimilar antigen recognition profiles, but strains sharing the H-2b haplotype (B10, BALB/B) recognized a low mol. wt antigen (20-23 kD) not recognized by any other strain, suggesting an exclusively H-2b restriction in the recognition of this antigen. These results support the conclusion that both H-2-linked and background genes play important roles in controlling the humoral immune response to T. muris infection.

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PubMed1989

Immunity to coccidiosis: T-cell control of infection with Eimeria vermiformis in mice does not require co-operation with inflammatory cells.

The necessity for co-operation between lymphocytes and myeloid-derived inflammatory cells in the mediation of anti-coccidial immunity was investigated using mice infected with Eimeria vermiformis. Reciprocal exchange of immune lymphocytes between H-2 compatible strains of contrasting susceptibility to infection (resistant BALB/B and susceptible C57BL/10) resulted in successful transfer of immunity in both homologous and heterologous exchanges. Recipients of immune cells, whatever their original response phenotype, expressed a high degree of immunity to infection, indicating that the differential susceptibility of the strains is a property of their lymphoid cells and is not attributable to their capacity to mount inflammatory responses. This conclusion was confirmed by the successful adoptive transfer of immunity into NIH mice previously exposed to 600 rad X-irradiation; at this level of irradiation inflammatory responsiveness is severely depressed. Additional confirmation that strain-response phenotype is lymphocyte dependent and that immune lymphocytes can mediate their effects against E. vermiformis without the intervention of inflammatory cells was obtained from studies on the mucosal mast cell response to infection. No correlation existed between the development of intestinal mastocytosis, an index of T-cell-mediated inflammatory responsiveness, and the expression of resistance to E. vermiformis in BALB/c (resistant), C57BL/10 (susceptible) and NIH (susceptible) mice.

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PubMed1989

Gamma interferon controls Eimeria vermiformis primary infection in BALB/c mice.

Neutralization of endogenous gamma interferon by treatment with a rat monoclonal antibody caused enhancement of infection with the protozoon Eimeria vermiformis in naive BALB/c mice. The effect was dose dependent and was apparent when a monoclonal antibody was given at 2 h before infection or up to 7 days postinfection, but it decreased with increasing time postinfection between days 4 and 7. The titers of parasite-specific antibodies in the serum were not significantly affected by the injection of monoclonal antibodies. Treatment during priming did not prevent the development of resistance to challenge, and treatment at the time of challenge did not abrogate established immunity. The results indicate that gamma interferon is involved in the control of primary infection with E. vermiformis in BALB/c mice but not in the expression of immunity to challenge.

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PubMed1989

Genetic control of eosinophilia. Analysis of production and response to eosinophil-differentiating factor in strains of mice infected with Trichinella spiralis.

Bone marrow cultures were established from mice undergoing parasitic eosinophilia after infection with Trichinella spiralis. In the presence of eosinophil-differentiation factor (EDF/IL-5) eosinophil precursor cells differentiated and could be identified and counted after a 7-day in vitro culture period. The EDF-bone marrow assay system was used to determine differences in bone marrow eosinophil precursor capacity between a number of inbred strains of mice. Bone marrow cultures from high peripheral eosinophil-response phenotype strains of mice (NIH, SWR & SJL) contained significantly greater numbers of eosinophil precursor cells than the low response strain C57BL/10. All congenic strains of mice with the B10 background, i.e. C57BL/10, B10.S, B10.BR and B10.G were found to have low eosinophil precursor capacity. Bone marrow cultures obtained from F1 hybrids (NIH x C57/BL10, SJL x C57/BL10 and SWR x C57BL/10) demonstrated high precursor numbers, indicating that low responsiveness is inherited as a recessive characteristic. When spleen cells from T. spiralis-infected, high and low responder strains of mice were stimulated in vitro with concanavalin A (Con A) or with parasite antigen, it was found that low responder phenotype strains produced quantities of two eosinophilopoietic lymphokines EDF and IL3, which were similar to, if not greater than high responder strains. This suggests that bone marrow precursor capacity and not T cell lymphokine release is an important limiting factor in determining strain-dependent eosinophilia.

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PubMed1988

Specific cross-immunity between Hymenolepis nana and H. diminuta: immunization with heterologous and homologous light infections.

The consequences of previous and concurrent infection with two related species of cestodes, Hymenolepis nana and H. diminuta, were studied in CD1 mice. A H. diminuta infection strongly affected the establishment and the survival of a secondary H. nana egg or cyst infection administered 30 days later. An infection of 20 H. nana eggs strongly protected against a 5-cyst H. diminuta challenge, whereas an infection of 10 H. nana cysts was ineffective; 20 H. nana eggs also protected against a challenge with 5 cysts of H. diminuta administered 5 days later. No effects were observed in either parasite during a concurrent infection established by administration of cysts. An H. nana egg-infection was unable to affect the establishment of a secondary H. nana cyst-infection given 1 month later; however a significant decrease in growth was found. Similar results were found when a primary H. nana egg-infection was followed 5 days later by the homologous cyst-infection. But an infection with 5 H. nana cysts was unable to protect against a homologous challenge of 5 cysts or 200 eggs. The reciprocal cross immunity between the heterologous parasites and the failure of protection of homologous challenges are discussed in relation to light infections.

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PubMed1988

The effects of H-2 and non-H-2 genes on the expulsion of the nematode Trichuris muris from inbred and congenic mice.

Two groups of H-2 congenic strains of mice were compared for their susceptibility to a primary infection with the nematode Trichuris muris. Mice of the BALB genetic background were markedly more resistant than mice of the B10 genetic background, as reflected by the rate of expulsion of T. muris from the large intestine. Within each of the two groups of H-2 congenic strains mice possessing the H-2k haplotype (BALB/k, B10.BR) were more susceptible to infection than mice expressing other haplotypes; B10 background strains expressing H-2b (B10) or H-2q (B10.G) alleles were the most resistant of the four congenic strains studied. Differential resistance was observed within three of the four B10 congenic strains and this is discussed in terms of rate of development of the protective immune response in relation to worm development. The results support the conclusion that both H-2-linked and non-H-2 genes play important roles in controlling the immune response which expels worms from the gut.

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PubMed1988

Immunity to coccidiosis: adoptive transfer in NIH mice challenged with Eimeria vermiformis.

The development of a reliable model for the adoptive transfer of immunity to coccidiosis (infection with Eimeria vermiformis in NIH mice) is described. More than 10(8) of a mixture of spleen and mesenteric lymph node (MLN) cells, given either intravenously or intraperitoneally, were required to transfer a significant degree of protection. Dividing cells, present in the donors at 10 or 14 days after priming, but not at 5 or 19 days, were shown to be the effectors. When examined separately, MLN cells were found to be superior to spleen cells, and the injection of as few as 5 x 10(7) was capable of substantially reducing the oocyst output from a challenge inoculum. The recipients of cells from primed mice had earlier, and sometimes higher, titres of specific antibodies in the serum but, overall, there was no correlation between these titres and protection. Further characterization of the cells responsible for adoptively transferring immunity to this infection should now be possible.

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PubMed1988

Suppression of mucosal mastocytosis by Nematospiroides dubius results from an adult worm-mediated effect upon host lymphocytes.

Infections with the nematode Nematospiroides dubius fail to elicit mucosal mast cell (MMC) responses in the intestines of host mice, and suppress MMC responses generated by heterologous infection. Larval N. dubius have the capacity to prime for mastocytosis, and to elicit this response in primed mice during a challenge, but only if adult worms are prevented from developing, either by anthelmintic treatment or by irradiation of the larvae themselves. The suppressive effect of the adult stage was confirmed in experiments where such worms were implanted directly into the intestines of mice primed by exposure to irradiated N. dubius larvae or concurrently infected with Trichinella spiralis. Data on the mechanisms underlying this suppressive effect were obtained from experiments involving the adoptive transfer of mastocytosis by mesenteric lymph node cells (MLNC) from T. spiralis infected mice. When MLNC were taken from mice infected concurrently with both T. spiralis and N. dubius no enhanced mastocytosis was seen in recipients after challenge with T. spiralis. Exposure of MLNC from T. spiralis infected donors to the presence of adult N. dubius after transfer did not reduce the adoptively transferred response. The response was also unaffected when MLNC from adult N. dubius infected mice were simultaneously transferred with MLNC from T. spiralis donors. It is concluded that the suppressive effect of adult N. dubius upon the expression of mucosal mastocytosis acts upon the generation of lymphocytes capable of promoting the development of MMC from precursor cells.

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PubMed1988

Antigenic cross-reactivity between the human whipworm, Trichuris trichiura, and the mouse trichuroids Trichuris muris and Trichinella spiralis.

Cross-reactivity was demonstrated between circulating antibodies from Trichuris trichiura-infected humans and T. muris-infected mice for heterologous antigen preparations. Mouse immune sera raised against excretory/secretory (E/S) products and anterior end homogenate from adult T. muris showed marked affinity for T. trichiura adult homogenate in ELISA, and 35S-methionine-labelled adult T. muris E/S products were precipitated by T. trichiura infection sera. Monoclonal antibodies recognizing a 48 kD Trichinella spiralis muscle larval beta-stichocyte granule antigen also showed avidity for T. trichiura adult homogenate in ELISA, as did serum from mice with patent T. muris worm burdens. This cross-reactivity is thought to result from shared stichocyte antigens and the relevance of this observation is discussed.

Animals↗
PubMed1988

Resistance to infection with Eimeria vermiformis in mouse radiation chimeras is determined by donor bone-marrow cells.

The course of infection with Eimeria vermiformis was determined in BALB/b, BALB/c, and C57BL/10ScSn (B10) mice and in radiation chimeras prepared from the H-2-compatible BALB/b and B10 mice. The BALB strains, irrespective of H-2 haplotype, were resistant, the B10 mice were susceptible, and in the chimeras infection was characterized by the genotype of the donated bone-marrow cells and not by the phenotype of the recipient. Thus, the genetic control of relative resistance or susceptibility to infection with this parasite is expressed through bone-marrow-derived cells.

Animals↗
PubMed1988

Mediation of immunity to Eimeria vermiformis in mice by L3T4+ T cells.

Immunity to infection with Eimeria vermiformis was transferred in NIH mice by both the nylon wool-adherent (B-cell-enriched) and nonadherent (T-cell-enriched) fractions of lymphocytes (spleen and mesenteric lymph node) taken from infected donors. Transfer was more variable with the adherent fraction, and when contaminating T cells were removed by treatment with anti-Thy1 monoclonal antibody (MAb) and complement, this fraction lost all protective activity. The protective effect of T-cell-enriched populations of mesenteric lymphocytes was abrogated by treatment with anti-L3T4 MAb and complement in vitro before transfer or by opsonization with this MAb in vitro before intravenous inoculation into recipients. Similar treatments of cells with anti-Lyt2 MAb did not have this effect, confirming that Thy1+ L3T4+ cells mediate the adoptive transfer of immunity to E. vermiformis. Thy1+ L3T4+ cells were also shown to limit the replication of E. vermiformis in primary infections: mice depleted of this subset (by thymectomy followed by intravenous injection of anti-L3T4 MAb) passed greater numbers of oocysts over a longer period of time than did mice similarly depleted of Lyt2+ cells.

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PubMed1988

Medium conditioned by spleen cells of Nematospiroides dubius-infected mice does not support development of cultured mast cells.

The ability of different conditioned media to support mast cell development from precursors in normal bone marrow was evaluated. Many mast cells developed in bone marrow cultures containing medium conditioned by concanavalin-A-stimulated spleen cells of normal mice, Trichinella spiralis-infected mice, or mice infected for 6 days by Nematospiroides dubius. By contrast, medium conditioned by concanavalin-A-stimulated spleen cells of mice having 18-day infections of the nematode N. dubius failed to support mast cell development. The difference between medium conditioned by spleen cells of mice having 6-day versus 18-day infections of N. dubius may be due to the life cycle stage of the parasite, larval or adult, present at those times. These results from cultures are consistent with those from in vivo studies in which mice given primary infections of N. dubius failed to develop the intestinal mastocytosis characteristic of nematode infections.

Animals↗
PubMed1988

Granule proteinases define mast cell heterogeneity in the serosa and the gastrointestinal mucosa of the mouse.

In order to define further mast cell heterogeneity in the mouse, affinity-purified antibodies against a 28,000 MW serine proteinase from mouse intestinal mast cells (IMCP) and against rat mast cell proteinase I (RMCPI) were used to characterize mast cell cytoplasmic granules immunohistochemically. On Western blot, anti-IMCP cross-reacted with RMCPI and with a 25,000 MW antigen from isolated mouse serosal mast cells (SMC). Anti-RMCPI did not react with IMCP, although it identified the same 25,000 MW antigen from SMC. Isolated SMC (85-90% pure) lacked the 28,000 MW IMCP on Western blot, even though, immunohistochemically, the cells were stained with both anti-RMCPI and anti-IMCP. Anti-IMCP stained the granules of more than 85% of all mast cells detected with toluidine blue in the tongue or gastrointestinal mucosa. The specificity of anti-RMCPI which, in the rat, detects very few mucosal mast cells was almost identical to that of anti-IMCP for murine tongue and gastric and large intestinal mucosae, but a significant proportion of cells in distal jejunal, ileal and caecal mucosae were not stained with this antibody. The immunohistochemistry of the large numbers of mast cells recruited to jejunum following infection 10 days previously with 300 Trichinella spiralis muscle larvae was similar to that of uninfected control mice. The results show that considerable mast cell heterogeneity exists within the gastrointestinal mucosa of the mouse and indicate that there are both similarities and differences between mouse and rat in the distribution of mast cells and of their granule proteinases.

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PubMed1988

Genetic control of mast cell development in bone marrow cultures. Strain-dependent variation in cultures from inbred mice.

A comparison was made of the capacity of bone marrow cells (BM) from genetically distinct strains of mice to develop into mast cells under defined conditions of in vitro culture. In the presence of conditioned media derived from ConA treated spleen cells from normal or Trichinella spiralis-infected mice, mast cell development occurred readily. After 21 days of culture mast cells comprised more than 90% of the total cell population. BM taken from certain strains of mice (SWR and NIH) produced large numbers of mast cells, total cell numbers increasing between 2 and 5 fold; other strains (C57BL/10 [B10] B10 congenics) produced relatively few mast cells, total cell numbers not increasing above the starting concentration or declining during culture. The genetic factors determining the strain-response phenotype (no. of mast cells in culture) were predominantly associated with the background genome. No significant differences in response were noted between the B10 congenic strains B10 [H-2b], B10.G [H-2q] or B10.BR [H-2k], which differ only at the MHC, whereas major differences were seen between B10.G and the other H-2q strains [SWR and NIH]. Response phenotype was not inherited as a simple dominant trait; F1 progeny of high x low responder strains were intermediate between the parental values. The expression of genetic influences upon mast cell response phenotype appears to be at both the level of mast cell precursor cells, as determined from limiting dilution assays of BM from high, low and F1 (high x low) strains, and at the level of mast cell proliferation, as determined by repeated sub-culture of mast cells from these strains.

Animals↗
PubMed1988

Prenatal sensitisation in experimental filariasis: observations on Acanthocheilonema viteae infections in mice.

The probability that in utero exposure to filarial antigens may influence the outcome of a subsequent infection has been investigated using a laboratory model whereby BALB/c mice are implanted with adult, female Acanthocheilonema viteae in order to generate a high-level, long lasting microfilaraemia. When infected using this procedure, BALB/c and (BALB/c x B10) F1 mice can be defined as susceptible and resistant respectively in terms of the microfilaraemia produced. By using microfilaraemic BALB/c mice as mothers, BALB/c and F1 offspring were exposed to the possibility of in utero infection. The finding of microfilariae in foetal tissues and their presence in the blood of two week old mice confirmed the transplacental transmission of parasites in both cases, BALB/c and F1 progeny born to microfilaraemic mothers failed to support a full infection from the L3 stage; similarly, progeny implanted with female worms were as sus-ceptible and resistant respectively as unexposed BALB/c and F1 controls. Spleen cells from in utero exposed, two week old BALB/c and F1 mice recognised filarial antigens in lymphocyte proliferation assays, as did their microfilaraemic mothers. In Western Blot studies, sera from such mice and from foetal, in utero exposed BALB/c mice recognised the same spectrum of A. viteae antigens as their mothers, which strongly suggests the transplacental transfer of maternal antibody. These results demonstrate that the A. viteae-mouse model may be useful in studying transplacental transmission and prenatal sensitisation in experimental filariasis.

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