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Biomedical subjects

C M Warner

Publications and source records attributed to C M Warner.

At least 73 records · Page 4Linked to original sources

Genetic control of immune response to pseudorabies and atrophic rhinitis vaccines: I. Heterosis, general combining ability and relationship to growth and backfat.

Data from 988 pigs from 119 litters farrowed in two seasons of a three-breed diallel crossbreeding experiment were analyzed to estimate general combining abilities of breeds and heterosis for humoral immune response to pseudorabies virus and atrophic rhinitis vaccines. Twenty purebred boars and 85 sows of the Duroc, Landrace and Yorkshire breeds were mated to provide the nine breed-of-sire and breed-of-dam combinations. Immune response was measured after vaccination. A modified-live pseudorabies virus (PR) vaccine was administered to piglets at 28 d of age and response measured as log2 serum neutralization titers at 56 d. An inactivated B. bronchiseptica bacterin was administered at 28, 42 and 112 d. Antibody levels were measured relative to positive and negative controls at 28, 56 and 119 d by using an enzyme-linked immunosorbent assay. The results of this study showed that ranking by breed of sire and breed of dam did not differ for general combining ability, and no evidence of significant heterosis for any immune responses was observed. Higher immune response at 56 d to B. bronchiseptica vaccine was associated with lower weaning weight (r = -.09, P less than .01). Correlations of days to 100 kg with 56-d and 119-d B. bronchiseptica antibody levels were .15 (P less than .01) and .12 (P less than .01). The relationship between humoral immune response to PR vaccine and growth traits was similar to that observed for B. bronchiseptica vaccine. Immune response to both antigens was not associated with backfat thickness.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗

Genetic control of immune response to pseudorabies and atrophic rhinitis vaccines: II. Comparison of additive direct and maternal genetic effects.

Data from 52 litters farrowed in two seasons of a cross-fostering experiment were analyzed to estimate variances and covariances for additive direct and maternal genetic effects on immune response to pseudorabies virus and B. bronchiseptica vaccine. Twenty purebred boars and 44 sows of the Duroc, Landrace and Yorkshire breeds were used. Immune response was measured after vaccine challenge. A modified-live pseudorabies (PR) vaccine was administered to piglets at 28 d of age; response was measured by log2 serum neutralization titers at 56 d. An inactivated B. bronchiseptica bacterin was administered at 28, 42 and 112 d. Antibody levels were measured relative to positive and negative controls at 28, 56 and 119 d by using an enzyme-linked immunosorbent assay (ELISA). Results from this study for heritability were .18 +/- .09 for PR titer and .15 +/- .07 and .52 +/- .15 for 56- and 119-d ELISA values, respectively. The variability due to nurse environment (maternal genetic variance and common environmental variance) as a percentage of phenotypic variance was 11.1% for PR titers and 29.6 and 8.8% for 56- and 119-d ELISA values, respectively. The heritabilities estimated in this study indicate that, if improved immune response to vaccines is desired, selection may be useful. However, the importance of maternal environment would make early selections less accurate than selections based on immune response measured later in life.

Animals↗

A chicken sex-limited protein that crossreacts with the fourth component of complement.

Plasma samples from more than 300 inbred chickens were screened by using an immunofixation technique with antibody against the fourth component of complement (C4) from humans. Precipitation patterns of plasma from adult male and sexually immature birds, either male or female, were identical. Plasma from egg-laying hens demonstrated a distinctly different precipitation pattern compared with plasma of other birds, with one additional band appearing 14 to 9 days before production of the first egg. The banding pattern could not be induced in males by progesterone injection and remained unchanged in molted female birds.

Animals↗

Molecular analysis of the chicken major histocompatibility complex gene and gene products.

New technologies are enabling researchers to conduct analysis of the molecular structure of the genes and gene products of the major histocompatibility complex (MHC). Two of these new technologies are the production of monoclonal antibodies by hybridomas and analysis of deoxyribonucleic acid (DNA) by restriction fragment length polymorphisms (RFLP) on Southern blots. Monoclonal antibodies, because of their exquisite specificity, can be used to isolate purified MHC antigens for further study. The RFLP analysis can be used to examine differences in the MHC at the DNA level. This paper describes the two aforementioned technologies and their application to molecular analysis of the chicken MHC.

Animals↗

Genetic manipulation of the major histocompatibility complex.

The genes of the major histocompatibility complex (MHC) are prime candidates for genetic engineering of domestic species because of their importance in many biological phenomena, including disease resistance and reproduction. One MHC-linked gene, the Ped gene in the mouse, has been shown to influence embryo development and survival. The Ped gene has mapped to the Qa-2 subregion of the mouse MHC, the H-2 complex. Future studies are aimed at determining, at the DNA and protein levels, the structure of the Ped gene and its gene product. There is preliminary evidence that there may be MHC-linked Ped-like genes that influence reproduction in other species. The search for Ped-like genes in domestic species has been hampered by the limited data available describing the molecular structure of the MHC of species other than mouse and man. This paper describes the use of restriction fragment length polymorphism analysis to study the MHC of two domestic species, the pig and the chicken. Major histocompatibility complex effects on reproduction have been reported for both the pig and the chicken. The long-range goal is to identify and isolate advantageous alleles that could then be injected into recipient embryos to create more reproductively efficient animals.

Animals↗

Effect of absorbed and nonabsorbed anti-H-2 antiserum on mouse blastocysts.

Conventional antisera and monoclonal antibodies have been used to demonstrate the presence of H-2 antigens on preimplantation mouse embryos. In this study, the specificity of previously used anti-H-2 conventional antisera was tested by absorption of the antisera on spleen lymphocytes. It was found that absorption of the anti-H-2 antisera removed all of the antibody reactive with lymphocytes, but only about half of the antibody reactive with embryos. The effect of absorbed and nonabsorbed anti-H-2 antisera on mouse blastocysts was tested both by cytotoxicity assays and by electron microscopy. The results suggest that conventional antisera do indeed detect H-2 antigens on mouse embryos, but they may detect other, as yet undefined, antigens as well.

Absorption↗

Variations in the amount of glucose phosphate isomerase in lymphocytes and erythrocytes from A/J and C57BL/6J mice.

In a comparative study of A/J (Gpi-1a) and C57BL/6J (Gpi-1b) mice, we observed that erythrocytes of A/J mice exhibited significantly higher glucose phosphate isomerase (GPI) activity compared to erythrocytes of C57BL/6J mice on a per cell, per gram of protein, or per gram of hemoglobin basis. Higher GPI activity per cell was detected for peripheral blood lymphocytes of A/J compared to C57BL/6J mice. (A/J X C57BL/6J)F1 mice expressed erythrocyte and peripheral blood lymphocyte GPI activities intermediate to those of the parental mouse strains. The GPI activities of spleen lymphocytes from A/J, C57BL/6J, or (A/J X C57BL/6J)F1 mice were not significantly different from each other. The higher activity in the A/J mice could be due to GPI of a higher catalytic rate or to the presence of more GPI molecules. In order to distinguish these two possibilities, GPI was purified to homogeneity from both strains of mice. The specific activities (activity per milligram of protein) of the purified enzymes from the two strains were found to be similar, indicating that GPI from the A/J strain was not a more active enzyme. Antibody to the purified enzymes was prepared and used in an enzyme-linked immunosorbent assay (ELISA) to compare the relative amounts of enzyme molecules in cells of A/J and C57BL/6J mice. Results of the ELISA tests on peripheral blood lymphocytes indicated that A/J mice contain more molecules of GPI per cell and, therefore, have a higher GPI activity than C57BL/6J mice.

Animals↗

Lymphocyte aging in allophenic mice.

Allophenic mice are chimeras which are produced from the aggregation of two genotypically distinct embryos. In this study, embryos from the C57BL/6J and A/J strains were used to produce C57BL/6J----A/J allophenic mice. These strains were chosen because of their markedly different lifespans, their different glucose phosphate isomerase (GPI) isozymes, and their different H-2 haplotypes [C57BL/6J: long-lived, Gpi-1b, H-2b; A/J: short-lived, Gpi-1a, H-2a]. The mice were bled at two month intervals and the composition of their peripheral blood lymphocytes determined at each point from analysis of GPI isozymes and H-2 antigens. It was found that the proportion of long-lived (C57BL/6J) lymphocytes tended to increase with age. Moreover, the total lifespan of the allophenic mice was directly related to the percentage of long-lived lymphocytes in their peripheral blood.

Aging↗

Synthesis of H-2 antigens by preimplantation mouse embryos.

An enzyme-linked immunosorbent assay (ELISA), which utilized anti-H-2 monoclonal antibody, was used to detect H-2 antigens on preimplantation mouse embryos. All embryonic stages studied, including unfertilized eggs and 1-cell, 2-cell, 8-cell, and blastocyst-stage embryos, showed the presence of H-2 antigens. To prove that the H-2 antigens were not cytophilically adsorbed to the embryos, blastocysts were treated with papain to strip off the H-2 antigens, and then the embryos were further incubated to allow the H-2 antigens to regenerate. After a 3-h incubation time, 60% of the H-2 antigens on the embryos had reappeared, proving that the H-2 antigens were synthesized by the embryos themselves.

Animals↗

Glucose phosphate isomerase activity in C57BL/6 and a mice of different ages.

Glucose phosphate isomerase (GPI) enzyme activity was measured in two strains of mice, A/HeNNial (Gpi-1a) and C57BL/6NNia1 (Gpi-1b). Seven solid tissues (muscle, brain, heart, kidney, liver, lung, spleen) and three cell types (peripheral blood lymphocytes, spleen lymphocytes, erythrocytes) were analyzed for GPI activity in mice from 6 to 36 months of age. No major changes in enzyme activity with age were found. The most striking observation was that A/HeNNial mice showed a significantly higher GPI activity than C57BL/6NNia1 mice in four of the solid tissues (muscle, heart, kidney, spleen) and two of the cell types (peripheral blood lymphocytes, erythrocytes) analyzed.

Aging↗

A highly sensitive method for the detection of cell surface antigens on preimplantation mouse embryos.

An enzyme-linked immunosorbent assay (ELISA) was developed to detect H-2 antigens on preimplantation mouse embryos. The presence of these antigens was shown on early blastocysts from the outbred strain CF1. The assay consists of treating the embryos with purified anti-H-2 monoclonal antibodies followed by treatment with rabbit anti-IgG and protein A-beta-galactosidase conjugate. Removal of the zonae pellucidae by pronase did not change the sensitivity of the assay. However, longer treatment of the embryo surface with pronase eliminated the binding of the anti-H-2 antibodies. The embryo ELISA was shown to be more sensitive than an embryo cytotoxicity assay also described in this paper. The ELISA technique should be useful for future studies of the surface of early embryos.

Animals↗

Demonstration of H-2 antigens on preimplantation mouse embryos using conventional antisera and monoclonal antibody.

Mouse embryos at the 2-cell, 8-cell, and blastocyst stages of development were examined for the presence of H-2 antigens by immunoperoxidase labeling and transmission electron microscopy. Conventional antisera made in congenic mouse strains were used to study embryos of four different haplotypes: b, a, k, and d. Blastocysts showed uniform heavy labeling of all cells of the trophectoderm, 8-cell embryos showed lighter labeling of only some of the cells, and 2-cell embryos showed no labeling. Similar results were found for all four haplotypes studied. In addition, monoclonal antibody 11-4.1 (anti-Kk) was reacted with homologous (H-2k) and heterologous (H-2b) blastocysts. Positive results with the monoclonal antibody corroborates the concept that H-2 antigens are expressed on early mouse embryos.

Animals↗

Breed and swine lymphocyte antigen haplotype differences in agglutination titers following vaccination with B. bronchiseptica.

Genetic differences in immune response to B. bronchiseptica after vaccination with a commercial B. bronchiseptica bacterin were investigated in 1,069 8-wk-old pigs. These pigs were from 65 litters born in the spring and 66 litters born in the fall of 1982 and were purebreds from the Chester White (n = 128), Duroc (n = 281), Hampshire (n = 143), Landrace (n = 309) and Yorkshire (n = 208) breeds. Each litter was raised separately. Individual pigs were vaccinated im at 4 and 6 wk of age with 2 ml of B. bronchiseptica bacterin. At 8 wk of age, 8 ml of blood were collected from each animal and serum prepared to determine agglutinating antibody titers against B. bronchiseptica bacterin by a bacterial agglutination method. In addition, lymphocytes were separated from 1 ml of heparinized blood and used to determine Swine Lymphocyte Antigen (SLA) haplotypes by using cytotoxic antibodies against the SLA complex. Antisera for 3 SLA haplotypes were made available by the National Institutes of Health. Results indicated that breed of pig (P less than .01) and dam of pig (P less than .01) affected the immune response of the pig after B. bronchiseptica vaccination. Higher immune response was also associated (P less than .05) with one of the SLA haplotypes tested. Heritability estimates for immune response following vaccination were .10 +/- .12 (half-sib) and .42 +/- .19 (full-sib). Results suggest that the relationship of the SLA complex to immune response in the pig and nonadditive genetic and maternal effects on immune response should be further investigated.

Agglutination Tests↗

Genetic differences in serum-neutralization titers of pigs after vaccination with pseudorabies modified live-virus vaccine.

Four-week-old pigs of the Chester White, Duroc, Hampshire, Landrace, and Yorkshire breeds (n = 518) were vaccinated with a pseudorabies modified live-virus vaccine to determine whether genetic differences existed for immune response after vaccination. All pigs and their dams (sows) were tested before vaccination to determine preimmunization antibody titers, using a microtitration serum-neutralization (SN) test. The SN test results of sows were negative, as were preimmunization tests of the pigs. At 4 weeks after pigs were vaccinated, additional blood samples were collected from the pigs, and end-point SN titers were determined, using a 2-fold dilution scheme. Small, but statistically significant, breed differences existed for antibody response, with Yorkshire and Chester White pigs having the highest response, and Duroc and Landrace pigs, the lowest. Differences among sire progeny groups were small, but there were significant differences among dams. Genetic differences as seen by differences among breeds indicates that the efficacy of vaccines may vary from breed to breed and that vaccine trials should not neglect this potential source of variation.

Animals↗

Measurement of serum antibody in swine vaccinated with Bordetella bronchiseptica: comparison of agglutination and enzyme-linked immunosorbent assay methods.

The immune responses of 514 pigs from 5 swine breeds (Chester White, Duroc, Hampshire, Landrace, Yorkshire) to vaccination with Bordetella bronchiseptica were measured by agglutination and enzyme-linked immunosorbent assay (ELISA) methods. Both assays showed higher antibody levels in sera of pigs after vaccination than in sera of the pigs before vaccination. The variability of the responses among breeds was greater for the agglutination method than for the ELISA method. The ELISA proved to be more sensitive than the agglutination method and could detect antibody in serum samples diluted at least 100-fold more than those used in the agglutination procedure. The correlation of antibody titers obtained by the 2 methods was small, but statistically (P less than 0.01) significant. The ELISA should be useful for determinations of antibody responses of swine to B bronchiseptica.

Agglutination Tests↗

Unusual glucose phosphate isomerase isozyme patterns in lymphocytes from two C57BL/6J in equilibrium A/J allophenic mice.

Analysis of C57BL/6J in equilibrium A/J allophenic mice for their lymphocyte composition, using H-2 antigens as external markers, and glucose phosphate isomerase (GPI) isozymes as internal markers, has led to the discovery of two unusual mice. Both mice showed heterodimers of GPI isozymes upon electrophoresis of the lymphocyte lysate. Specific anti-H-2 antisera confirmed that the cells of the mice were of C57BL/6J and A/J origin, as expected, but that the "A/J" cells seemed to behave as F1 hybrids containing the Gpi-1a and Gpi-1b alleles. Possible origins of the Gpi-1b allele in the "A/J" cells are discussed.

Animals↗