PubMed Health⌕ Search

Biomedical subjects

W E Briles

Publications and source records attributed to W E Briles.

At least 19 recordsLinked to original sources
PubMed2004

Non-major histocompatibility complex alloantigen genes affecting immunity.

An alloantigen is a genetically determined cell-surface molecule detected by specific antisera. An identifying letter has been assigned to each genetic locus responsible for the 12 distinct families of alloantigens: A, B, C, D, E, H, I, J, K, L, P, and R. The genes of each system segregate independently of the other systems, except that the A and E are very closely linked (0.5 centimorgans). Selection experiments over numerous generations have revealed distinct changes in gene frequency of the A-E alloantigens, suggesting immune responses associated with susceptibility to coccidiosis, response to immunizations with SRBC, and selection for size of the bursa of Fabricius. Immune response effects of the C system of alloantigen genes are indicated by distinct gene frequency changes following selection for response to SRBC, selection for size of bursa of Fabricius, and macrophage nitrite production after lipopolysaccharide (LPS) stimulation. Immune response effects of the D system of antigens are indicated by data from genetic selection for response to immunization with SRBC, selection for bursa size, and macrophage nitrite and cytokine interleukin (IL)-6 production following LPS stimulation. Immune response effects of the I system genes are indicated by distinct gene frequency changes in lines selected for bursa size and within family comparisons for macrophage nitrite and cytokine IL-6 production following LPS stimulation. Effects of the L system, consisting of only 2 alleles, are indicated by the gene frequency changes following selection for bursa size, direct comparison of genotypes within families for monocyte phagocytosis, susceptibility to coccidiosis, outcome of Rous sarcomas, and immune responses to SRBC and Brucella abortus. Genotypes of the P alloantigen system were directly compared within families of fully pedigreed chicks with significant differences for monocyte phagocytosis. An experimental procedure for simultaneously testing for immune responses of genotypes of 9 of the alloantigen systems (A, B, C, D, E, H, I, L, and P) has been established by producing test progeny from a single cross of parent lines segregating for genes of each of the systems.

Animals↗
PubMed2003

Resistance, susceptibility, and immunity to cecal coccidiosis: effects of B complex and alloantigen system L.

This study examined alloantigen system L effects on resistance to initial infection and acquired immunity to Eimeria tenella infection in three B complex genotypes. Experimental progeny segregating for B and L genotypes were produced from pedigree matings of B2B5 L1L2 sires and dams. Chicks were weighed and inoculated with 30,000 E. tenella oocysts at 6 wk of age to evaluate resistance in four trials (n = 262). Immunity was studied in four additional trials (n = 244) by immunizing progeny with 500 E. tenella oocysts per day for 5 d beginning at 5 wk of age. Two weeks after the last immunization dose, the birds were weighed and challenged with 30,000 E. tenella oocysts. All birds were weighed again and scored for cecal lesion 6 d after the 30,000 oocyst dose challenge. Weight gain and cecal lesion scores were evaluated by ANOVA. Major histocompatibility (B) complex genotypes B2B2 and B5B5 did not affect resistance to initial challenge with E. tenella based on lesion score and weight gain. However, after immunization, the B5B5 and B2B5 genotypes had significantly lower cecal scores than the B2B2 genotype when the birds were rechallenged. Weight gain was not affected among immunized birds. No significant L system effects with or without immunization were detected. These results are consistent with previous research demonstrating B complex effects on immunity to cecal coccidiosis.

Animals↗
PubMed2002

Single-strand conformation polymorphism (SSCP) assays for major histocompatibility complex B genotyping in chickens.

We have developed a DNA-based method for defining MHC B system genotypes in chickens. Genotyping by this method requires neither prior determination of allele-specific differences in nucleotide sequence nor the preparation of haplotype-specific alloantisera. Allelic differences at chicken B-F (class I) and B-L (class II) loci are detected in PCR single-strand conformation polymorphism (SSCP) assays. PCR primer pairs were designed to hybridize specifically with conserved sequences surrounding hypervariable regions within the two class I and two class I loci of the B-complex and used to generate DNA fragments that are heat- and formamide-denatured and then analyzed on nondenaturing polyacrylamide gels. PCR primer pairs were tested for the capacity to produce SSCP patterns allowing the seven B haplotypes in the MHC B congenic lines, and seven B haplotypes known to be segregating in two commercial broiler breeder lines to be distinguished. Primer pairs were further evaluated for their capacity to reveal the segregation of B haplotypes in a fully pedigreed family and in a closed population. Concordance was found between SSCP patterns and previously assigned MHC types. B-F and B-L SSCP patterns segregated in linkage as expected for these closely linked loci. We conclude that this method is valuable for defining MHC B haplotypes and for detecting potential recombinant haplotypes especially when used in combination with B-G (class IV) typing by restriction fragment pattern.

Animals↗
PubMed2000

Adoptive transfer of infectious bronchitis virus primed alphabeta T cells bearing CD8 antigen protects chicks from acute infection.

Infectious bronchitis virus (IBV) infection and associated illness may be dramatically modified by passive transfer of immune T lymphocytes. Lymphocytes collected 10 days postinfection were transferred to naive chicks before challenge with virus. As determined by respiratory illness and viral load, transfer of syngeneic immune T lymphocytes protected chicks from challenge infection, whereas no protection was observed in the chicks receiving the MHC compatible lymphocytes from uninfected chicks. Protection following administration of T lymphocytes could be observed in chicks with three distinct MHC haplotypes: B(8)/B(8), B(12)/B(12), and B(19)/B(19). Nearly complete elimination of viral infection and illness was observed in chicks receiving cells enriched in alphabeta lymphocytes. In contrast, removal of gammadelta T lymphocytes had only a small effect on their potential to protect chicks. The adoptive transfer of enriched CD8(+) or CD4(+) T lymphocytes indicated that protection was also a function primarily of CD8-bearing cells. These results indicated that alphabeta T lymphocytes bearing CD8(+) antigens are critical in protecting chicks from IBV infection.

Acute Disease↗
PubMed2000

Allelic complementation between MHC haplotypes B(Q) and B17 increases regression of Rous sarcomas.

Major histocompatibility (B) complex haplotypes B(Q) and B17 were examined for their effect on Rous sarcoma outcome. Pedigree matings of B(Q)B17 chickens from the second backcross generation (BC2) of Line UCD 001 (B(Q)B(Q)) mated to Line UCD 003 (B17B17) produced progeny with genotypes B(Q)B(Q), B(Q)B17, and B17B17. Six-week-old chickens were injected with subgroup A Rous sarcoma virus (RSV). The tumors were scored for size at 2, 3, 4, 6, 8, and 10 weeks postinoculation. A tumor profile index (TPI) was assigned to each bird based on the six tumor scores. Two experiments with two trials each were conducted. In Experiment 1, chickens (n = 84) were inoculated with 30 pock-forming units (pfu) RSV. There was no significant B genotype effect on tumor growth over time or TPI among the 70 chickens that developed tumors. Chickens (n = 141) were injected with 15 PFU RSV in Experiment 2. The B genotype significantly affected tumor growth pattern over time in the 79 chickens with sarcomas. The B(Q)B17 chickens had the lowest TPI, which was significantly different from B17B17 but not B(Q)B(Q). The data indicate complementation because more tumor regression occurs in the B(Q)B17 heterozygote than in either B(Q)B(Q) or B17B17 genotypes at a 15 pfu RSV dose and significantly so compared to B17B17. By contrast, the 30 pfu RSV dose utilized in the first experiment overwhelmed all genotypic combinations of the B(Q) and B17 haplotypes, suggesting that certain MHC genotypes affect the immune response under modest levels of viral challenge.

Alleles↗
PubMed2000

Further tests for genetic linkages of three morphological traits, three blood groups, and break points of two chromosome translocations on chromosome one in the chicken.

Two matings were conducted to further test the locations of the pea comb (P*), blue egg shell color (O*), and tardy feathering (T*) loci. In each mating a different chromosome rearrangement break point (R(B)) was tested against the three loci. Independent segregation was noted between the traits and the R(B) when the R(B) was on the long arm of chromosome 1. Significant linkage was noted when an R(B) on the short arm was tested against the three markers, indicating that the loci for P*, O*, and T* are on the short arm. Three blood group loci, EAD*, EAI*, and EAP*, were simultaneously tested against the short arm R(B). Independent segregation was noted in each instance, indicating that these blood group loci are not on the short arm of chromosome 1.

Animal Husbandry↗
PubMed2000

Nonmajor histocompatibility complex alloantigen effects on the fate of Rous sarcomas.

Rous sarcoma virus-induced tumor outcome is controlled by the MHC (B). Additional data, using controlled segregation in families, has indicated non-MHC effects as well, but few studies have focused on blood groups other than the B complex. Segregating combinations of genes encoding erythrocyte (Ea) alloantigen systems A, C, D, E, H, I, P, and L in B2B5 and B5B5 MHC (B) backgrounds were examined for their effects on Rous sarcomas. Six-week-old chickens were inoculated in the wing-web with 30 pfu of Rous sarcoma virus (RSV). Tumors were scored six times over a 10-wk period. A tumor profile index (TPI) was assigned to each chicken based on the six tumor size scores. Response was evaluated using tumor size at each measurement period, TPI, and mortality. The genotypes of Ea systems A, C, D, E, H, I, and P had no significant effect on any parameter in either B complex population. The Ea-L system had an effect on Rous sarcomas in the B2B5 intermediate responders and B5B5 progressors. Tumor size, TPI, and mortality were all significantly lower in B2B5 L1L1 chickens than in B2B5 L1L2 chickens. Mortality was lower in the B5B5 L1L1 birds than in B5B5 L1L2 chickens. It appears that the Ea-L system, or one closely linked, is acting in a manner independent of the B complex in response to RSV challenge.

Animals↗
PubMed2000

Alloantigen systems L and P influence phagocytic function independent of the major histocompatability complex (B) in chickens.

Synthetic parent stocks were designed to produce progeny among which alleles were simultaneously segregating for nine alloantigen systems, including the MHC (B). Chicks from Ancona-derived B19B19 females crossed with White leghorn B19B21 males were blood typed, resulting in genotypic categories for the A-E, C, D, H, I, L, and P loci with the objective of determining which, if any, of the eight non-MHC alloantigen systems influence or interact with the B system genotypes for blood monocyte phagocytic activity. Leukocytes obtained from whole blood at 2 and 4 wk were separated on a Fico/Lite LymphoH, density gradient and were allowed to adhere to glass coverslips. The resulting adherent monocyte monolayers were incubated with viable Escherichia coli for 1 h and stained with Leukostat, and the phagocytic monocytes and numbers of internalized bacteria per phagocytic monocyte were scored microscopically. The combined results from two separate trials demonstrated that the genotypes of the A-E, C, D, H, and I systems did not differ in the percentage of monocytes exhibiting phagocytosis, whereas significant differences were noted relative to the B system genotype at 2 wk of age (B19B21 > B19B19; P = 0.049), L at 4 wk (L1L1 > L1L2; P = 0.009), and P at 4 wk (P4P4 > P1P1; P = 0.047). The data were further analyzed to determine any interactions of P and L alloantigen genotypes with the B system genotypes; no such interaction was observed. These studies suggest that the L and P non-MHC alloantigen systems have the potential to influence immune responses by modulating phagocytic function in chickens. Furthermore, this modulation seems to be independent of the B (MHC) system.

Animals↗
PubMed2000

A consensus linkage map of the chicken genome.

A consensus linkage map has been developed in the chicken that combines all of the genotyping data from the three available chicken mapping populations. Genotyping data were contributed by the laboratories that have been using the East Lansing and Compton reference populations and from the Animal Breeding and Genetics Group of the Wageningen University using the Wageningen/Euribrid population. The resulting linkage map of the chicken genome contains 1889 loci. A framework map is presented that contains 480 loci ordered on 50 linkage groups. Framework loci are defined as loci whose order relative to one another is supported by odds greater then 3. The possible positions of the remaining 1409 loci are indicated relative to these framework loci. The total map spans 3800 cM, which is considerably larger than previous estimates for the chicken genome. Furthermore, although the physical size of the chicken genome is threefold smaller then that of mammals, its genetic map is comparable in size to that of most mammals. The map contains 350 markers within expressed sequences, 235 of which represent identified genes or sequences that have significant sequence identity to known genes. This improves the contribution of the chicken linkage map to comparative gene mapping considerably and clearly shows the conservation of large syntenic regions between the human and chicken genomes. The compact physical size of the chicken genome, combined with the large size of its genetic map and the observed degree of conserved synteny, makes the chicken a valuable model organism in the genomics as well as the postgenomics era. The linkage maps, the two-point lod scores, and additional information about the loci are available at web sites in Wageningen (http://www.zod.wau.nl/vf/ research/chicken/frame_chicken.html) and East Lansing (http://poultry.mph.msu.edu/).

Animals↗
PubMed1997

Immunogenetics of the A-E alloantigen complex.

The close linkage (0.5%) between the A and E erythrocyte alloantigen loci present a special challenge in the production of locus-specific typing antisera. The objective of the investigation was to determine immunogenetically the A-E haplotypes (genetically linked combinations of A and E antigens) existing in the locally maintained individuals of the New Hampshire (NH) and White Plymouth Rock (WR) breeds. The A and E alloantigens in these populations were identified using reference antisera previously produced in White Leghorns. A total of four A-E haplotypes were identified within each of the two breeds; A2E1, A6E2, A6E4, and A8E2 in WR and A2E1, A3E7, A7E4, and A8E2 in NH. Individuals of these two brown-egg breeds were backcrossed over several generations to a line of Ancona chickens homozygous at the A and E loci. Genetic segregation occurring over four generations resulted in nonrecombinant and recombinant progeny that were immunized reciprocally with the blood of siblings to raise antibodies reactive with the individual A and E antigens of the NH and WR stocks. The antisera resulting from the within-family alloimmunizations confirmed the haplotypes deduced in the WR and NH lines from the initial tests with the A and E reference antisera.

Animals↗
PubMed1996

Assignment of Rfp-Y to the chicken major histocompatibility complex/NOR microchromosome and evidence for high-frequency recombination associated with the nucleolar organizer region.

Rfp-Y is a second region in the genome of the chicken containing major histocompatibility complex (MHC) class I and II genes. Haplotypes of Rfp-Y assort independently from haplotypes of the B system, a region known to function as a MHC and to be located on chromosome 16 (a microchromosome) with the single nucleolar organizer region (NOR) in the chicken genome. Linkage mapping with reference populations failed to reveal the location of Rfp-Y, leaving Rfp-Y unlinked in a map containing >400 markers. A possible location of Rfp-Y became apparent in studies of chickens trisomic for chromosome 16 when it was noted that the intensity of restriction fragments associated with Rfp-Y increased with increasing copy number of chromosome 16. Further evidence that Rfp-Y might be located on chromosome 16 was obtained when individuals trisomic for chromosome 16 were found to transmit three Rfp-Y haplotypes. Finally, mapping of cosmid cluster III of the molecular map of chicken MHC genes (containing a MHC class II gene and two rRNA genes) to Rfp-Y validated the assignment of Rfp-Y to the MHC/NOR microchromosome. A genetic map can now be drawn for a portion of chicken chromosome 16 with Rfp-Y, encompassing two MHC class I and three MHC class II genes, separated from the B system by a region containing the NOR and exhibiting highly frequent recombination.

Animals↗
PubMed1996

Characterization of Mhc genes in a multigenerational family of ring-necked pheasants.

Little is known about the major histocompatibility (Mhc) genes of birds in different taxonomic groups or about how Mhc genes may be organized in avian species divergent by evolution or habitat. Yet it seems likely that much might be learned from birds about the evolution, organization, and function of this intricate complex of polymorphic genes. In this study a close relative of the chicken, the ring-necked pheasant (Phasianus colchicus), was examined for the presence and organization of Mhc B-G genes. The patterns of restriction fragments revealed by chicken B-G probes in Southern hybridizations and the patterns of pheasant erythrocyte polypeptides revealed in immunoblots by antisera raised against chicken B-G polypeptides provide genetic, molecular, and biochemical data confirming earlier serological evidence for the presence of B-G genes in the pheasant, and hence, the presence of a family of B-G genes in at least a second species of birds. The high polymorphism exhibited by the pheasant B-G gene family allowed genetic differences among individuals within the small experimental population in this study to be detected easily by restriction fragment patterns. Further evidence was found for the organization of the pheasant Mhc class I and class II genes into genetically independent clusters. Whether these gene clusters are fully comparable to the B and Rfp-Y systems in the chicken or whether yet another organization of Mhc genes has been encountered in the pheasant remains to be determined.

Amino Acid Sequence↗
PubMed1996

Association between the Rfp-Y haplotype and the incidence of Marek's disease in chickens.

Certain haplotypes at the major histocompatibility (B) complex (Mhc) of the chicken provide an easily demonstrated influence on tumor formation following infections with Marek's disease virus (MDV). Recognition that there is a second histocompatibility complex of genes in the chicken, Rfp-Y, comprised of Mhc class I and class II genes, some of which are at least transcribed, evokes the question of whether this gene complex might also influence the outcome of MDV infections. To test this hypothesis, pedigree-hatched chicks in families from the original Rfp-Y-defining stock in which three Rfp-Y and two B system haplotypes are segregating were challenged with the RB1B strain of MDV. Birds with the Y3/Y3 genotype were found to have 2.3 times the risk of developing a tumor compared with birds with other Rfp-Y genotypes combined (P <0.02). Additionally, birds carrying the BR9/B11 genotype had 2.3 times the risk of tumor formation, relative to birds with the B11/B11 genotype (P <0.02). We found no evidence for an interaction between genotypes within the B and Rfp-Y systems. These data provide evidence that Rfp-Y haplotypes, as well as B haplotypes, can significantly influence the outcome of infection with MDV.

Animals↗
PubMed1996

Immunoresponsiveness in chickens: association of antibody production and the B system of the major histocompatibility complex.

Lines of White Leghorn chickens were selected for high or low antibody response to sheep erythrocytes for five generations. The base population from which the experiment started was composed of individuals all of which were heterozygous at the MHC haplotypes B13 and B21. Body weights, egg production traits, and genotypes at the B system were monitored for all individuals in each generation. By Generations 4 and 5 there was separation of the two replicate lines selected for high titer from the two replicate lines selected for low titer. Over the course of the experiment, higher antibody titers and lower BW were associated with B21 and lower antibody titers and higher BW were associated with B13, although these relationships did not occur in every instance. Conclusions were that the B system was associated with antibody response, but that the chickens did not depend entirely upon that association for protection against foreign proteins. Also, the importance of having replicate lines in a selection experiment was shown.

Analysis of Variance↗
PubMed1995

B-complex recombinants and sarcoma regression: role of B-L/B-F region genes.

The anti-sarcoma response of three B complex recombinant haplotypes BR1(F24-G23), BR2(F2-G23), and BR3(F2-G23) was investigated. In a preliminary experiment, one male heterozygous for the BR1 recombinant haplotype and another heterozygous for the BR2 recombinant haplotype were each mated to females, some of which carried the respective recombinant. The anti-sarcoma response of progeny carrying the BR1 recombinant differed significantly from that of progeny carrying the BR2 recombinant. Subsequently, each of the three recombinant haplotypes was placed on each of four B haplotype complex backgrounds, and compared to B-G and B-L/B-F region controls on the same background haplotype. For each recombinant, significant differences in tumor growth were found between the recombinant and B-L/B-F control chickens on either one, two, or three of the four genetic backgrounds tested. For each recombinant, no differences were found between chickens carrying the recombinant and B-G region controls, which is further evidence that the gene(s) controlling Rous sarcoma growth lies in or near the B-L/B-F chromosomal region. Moreover, although the BR2 and BR3 recombinants appear to be identical serologically, they differed significantly in tumor growth suggesting that the two haplotypes are genetically different.

Animals↗
PubMed1994

Two Mhc class I and two Mhc class II genes map to the chicken Rfp-Y system outside the B complex.

Gene sequences highly similar to major histocompatibility complex (Mhc) class I and class II genes were recently recognized as mapping to a site in the genome of the chicken separate from the Mhc class I, class II, and B-G genes of the major histocompatibility (B) complex. The present study was undertaken to see whether this complex of Mhc-like genes designated as restriction fragment pattern Y (Rfp-Y) might reside in one of three clusters of cosmid clones contained within the molecular map of chicken Mhc genes, since only two of the three clusters can be assigned to the B system. To determine whether the third cluster (cluster II/IV) might contain Rfp-Y, a subclone (18.1) from within cluster II/IV near a polymorphic lectin gene was used to analyze the DNA of families in which Rfp-Y haplotypes are known to be segregating. The restriction fragment polymorphisms revealed by the 18.1 probe were found to segregate in parallel with the restriction fragment polymorphisms defining the Rfp-Y haplotypes, thus establishing the location of Rfp-Y within cosmid cluster II/IV. Two of six Mhc class I genes and two of five Mhc class II genes map to cosmid cluster II/IV, so a substantial fraction of chicken Mhc genes, including at least one that may be expressed, are located in a chromosomal region separate from the B system. In further linkage analyses, Rfp-Y was found to assort independently from more than 400 markers in the present linkage map of the chicken genome.

Alleles↗