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PubMed1987

A functional and biochemical analysis of bovine class II MHC antigens using monoclonal antibodies.

Monoclonal antibodies (MAbs) reacting with bovine (2) ovine (3), murine (1) or human (1) Class II MHC antigens were examined for reactivity with bovine peripheral blood leucocytes (PBL) and lymph node cells (LNC) by immunofluorescence, immunoprecipitation and the capacity to inhibit mixed lymphocyte responses (MLR), lectin- and antigen-induced blastogenesis. The 6 MAbs identified comparable percentages of Class II positive lymphocytes in PBL (40.8 to 54.2%) and LNC (6 to 11.5%) regardless of BoLA-A phenotype. Immunohistological staining of Class II MAb was localized principally to the lymphoid follicles in lymph nodes and to isolated epithelial reticular cells in the thymus. The anti-Class II MAb immunoprecipitated alpha- and beta- chains of 26-29K and 32-34K, respectively. These MAb inhibited proliferative responses in the MLR by between 25 and 74%, and diminished blastogenesis induced by specific antigens (purified protein derivative + PPD and ovalbumin) and B-lymphocyte mitogens (PPD, lipopolysaccharide and dextran sulphate) by between 45 and 75%, regardless of BoLA-A phenotype. In contrast, proliferation in response to concanavalin A and phytohaemagglutinin were unaffected by the anti- Class II MAb. Similarly these MAb did not affect lysis by cytotoxic T-lymphocytes, the activity of which was depressed by anti-Class I MAbs and monospecific alloantisera.

Animals↗
PubMed2005

Adaptation to carbon starvation: RNase III ensures normal expression levels of bolA1p mRNA and sigma(S).

bolA is a sigma(S)-dependent Escherichia coli morphogene involved in the general cellular adaptation to stress and cell division. In this report it is shown that endoribonuclease RNase III acts as a post-transcriptional modulator of bolA expression under carbon starvation conditions. Unexpectedly RNase III positively regulates bolA1p mRNA levels and stabilities. This effect is also observed when sulA, bfr, uspA and uspB transcripts were analyzed. RNase III is furthermore shown to be necessary for the normal expression of sigma(S), ensuring normal levels of rpoS mRNA and sigma(S) protein under glucose starvation. Since sigma(S) controls a complex regulon of stress-response genes, RNase III is proposed as possible modulator of bacterial cell response to stress.

Adaptation, Biological↗
PubMed2000

Association of bovine DRB3 alleles with immune response to FMDV peptides and protection against viral challenge.

We have analysed the influence of bovine MHC (BoLA) polymorphism on the immune response and degree of protection induced by peptide vaccines against foot-and-mouth disease (FMD) in cattle. The peptides used for animal immunisation were: A (VP1(138-156)), AT (peptide A linked to VP1(21-40)) and ACT (peptide A, linked to VP1(196-209) and VP1(21-40)). Sixteen different DRB3 types were found among the 46 cattle analysed by PCR-RFLP typing. No absolute correlation was observed, for any type, with the serum neutralising titres (SNT) values and the protection induced. However, among the most common haplotypes present, associations were observed between expression of different types with the levels of SNT and/or protection induced by peptides A and ACT. Thus, types DRB3.2*1, 3 and 7 were associated with increased levels of protection. In contrast, types DRB3.2*12 and 18 were associated non-protection, and DRB3.2*12 was also associated with low SNT titres. Overall, the results indicate that the polymorphism in BoLA class II molecules affects both the immune response and protection induced by potential FMD peptide vaccines.

Alleles↗
PubMed1999

Traditional healers and the treatment of sexually transmitted illnesses in rural Zambia.

Lately there has been increasing interest regarding the practice of traditional healers and their use of indigenous plants to treat illnesses. Twenty-three local healers (n'ganga) in Chiawa, rural Zambia, were interviewed about knowledge, practices, and their use of indigenous plants in the diagnosis and treatment of sexually transmitted illnesses (STIs) among male clients. They were also asked about their perceptions of modern medicine. The study revealed that all the n'ganga diagnosed and treated three main types of STIs. They named them as: songeya, doroba and bola-bola. They treated the illnesses with Strychnos cocculoides; Musa species; Solanum delegoense; Ximenia caffra; Diplorynchus condylocarpon; and Croton megalobotrys. Ten of the n'ganga perceived modern medicine to be effective against STIs and five of them sometimes referred some of the clients to the local health centre. It is being argued that a scheme to incorporate the n'ganga into STD control activities in which they can be utilised to refer clients to modern medical facilities can be beneficial. Given the necessary health information and support, the n'ganga may effectively execute this scheme.

Adult↗
PubMed2004

Slow motion, trapping, and sorting of water- and chloroform-soluble porphyrins in nanowells.

A two-step self-assembly procedure on smooth, aminated silica particles established holey monolayers. At first, single, flat-lying porphyrin tetraamides (A) were bound covalently, followed by the build-up of a rigid monolayer made of diamido bolaamphiphiles (bolas) around the porphyrin islands. "Nanowells" around porphyrin (A) bottoms with a uniform diameter of 2.2 nm and varying depths of 0.6, 1.0, or 1.5 nm depending on the length of the applied bolas were thus obtained. Oligoethylene headgroups solubilized the particles in water, ethanol, and chloroform/ethanol, and two hydrogen bond chains between the secondary amide groups prevented swelling of the monolayer. Manganese(III) porphyrinates (B) migrated from the bulk solution to the bottom of the form-stable nanowells with a speed of about 1 pm/s and were trapped there above porphyrin (A). After isolation of the (A,B) particles by centrifugation or ultrafiltration, the particles were suspended in a chloroform solution of a chlorin (C), which was also fixated irreversibly on the bottom of the nanowells. The nanowells thus contained three different porphyrins A,B,C in a noncovalent stack. The reverse sequence A,C,B was built-up correspondingly, first in chloroform/ethanol, and then in water. The "sorting" of A,B,C and A,C,B systems was characterized by visible spectra, sequence-dependent fluorescence quenching, and cyclic voltammetry of the top component. The molecular sorting method is the first of its kind and should be generally useful for the production of noncovalent reaction systems on any smooth surface.

Journal Article↗
PubMed1997

The use of bovine MHC class I allele-specific peptide motifs and proteolytic cleavage specificities for the prediction of potential cytotoxic T lymphocyte epitopes of bovine viral diarrhea virus.

Cell mediated immunity (CMI) is crucial for the defense against viruses. Cytotoxic T lymphocytes (CTLs) play a major role in CMI. They recognize endogenous antigenic peptides presented by antigen presenting cells in association with the major histocompatibility complex (MHC) class I molecules. The elucidation of the sequence of CTL epitopes of viruses should help in designing better vaccines. In this study, we have identified candidate epitopes restricted by five bovine MHC class I molecules that are potentially available for presentation to CTLs. The candidate peptide epitopes were identified by using the computer programs available as a part of the Genetics Computer Group package and applying the information on allele-specific peptide motifs and intracellular enzymatic cleavage patterns to the bovine viral diarrhea virus polyprotein. Several candidate peptides were found for each of the bovine lymphocyte antigens (BoLA)-A11, -A20, -HD1, and -HD6 whereas no peptide was found for BoLA-HD7. Based on this finding, the probable contribution of genomic segments of BVDV to the CTL response and strategies for recombinant vaccines are discussed.

Alleles↗
PubMed2001

Multi-primer target PCR for rapid identification of bovine DRB3 alleles.

Multi-primer target polymerase chain reaction (MPT-PCR) is a rapid method for the identification of specific BoLA-DRB3 alleles. In a single PCR reaction, the presence of two alleles associated with increased risk, DRB3.2*23 (DRB3*2701-2703, 2705-2707) and decreased risk, DRB3.2*16 (DRB3*1501, 1502), of mastitis in Canadian Holstein can be detected. Two outer primers amplify exon 2 of DRB3. Simultaneously, two inner, allele-specific primers amplify individual alleles. Initially, 40 cows previously typed by PCR-restriction fragment length polymorphism (PCR-RFLP) were genotyped using the multi-primer approach. An additional 30 cows were first genotyped by multi-primer target PCR, then by PCR-RFLP. All animals were correctly identified and there were no false positives. This technique can readily be modified to identify other BoLA alleles of interest.

Alleles↗
PubMed2001

Indigenous domestic breeds as reservoirs of genetic diversity: the Argentinean Creole cattle.

Contrary to highly selected commercial breeds, indigenous domestic breeds are composed of semi-wild or feral populations subjected to reduced levels of artificial selection. As a consequence, many of these breeds have become locally adapted to a wide range of environments, showing high levels of phenotypic variability and increased fitness under natural conditions. Genetic analyses of three loci associated with milk production (alpha(S1)-casein, kappa-casein and prolactin) and the locus BoLA-DRB3 of the major histocompatibility complex indicated that the Argentinean Creole cattle (ACC), an indigenous breed from South America, maintains high levels of genetic diversity and population structure. In contrast to the commercial Holstein breed, the ACC showed considerable variation in heterozygosity (H(e)) and allelic diversity (A) across populations. As expected, bi-allelic markers showed extensive variation in He whereas the highly polymorphic BoLA-DRB3 showed substantial variation in A, with individual populations having 39-74% of the total number of alleles characterized for the breed. An analysis of molecular variance (AMOVA) of nine populations throughout the distribution range of the ACC revealed that 91.9-94.7% of the total observed variance was explained by differences within populations whereas 5.3-8.1% was the result of differences among populations. In addition, the ACC breed consistently showed higher levels of genetic differentiation among populations than Holstein. Results from this study emphasize the importance of population genetic structure within domestic breeds as an essential component of genetic diversity and suggest that indigenous breeds may be considered important reservoirs of genetic diversity for commercial domestic species.

Alleles↗
PubMed2003

Polymorphisms in MHC-DRA and -DRB alleles of water buffalo (Bubalus bubalis) reveal different features from cattle DR alleles.

Seventy-five individuals of Bubalus bubalis belonging to four different breeds, three of river buffalo and one of swamp buffalo, were studied for polymorphism in MHC DRB (Bubu-DRB) and DRA (Bubu-DRA) loci. Eight alleles of Bubu-DRB were found, and all alleles in the swamp type were shared with the three river breeds. All alleles sampled from the breed of European origin (Mediterranean) were present in breeds sampled in Brazil, thus variability of this locus may have been preserved to a great extent in the more recently founded Brazilian population. Bubu-DRB alleles contained higher proportions of synonymous vs. non-synonymous substitutions in the non-peptide-binding sites (PBS) region, in contrast to the pattern of variation found in BoLA-DRB3, the orthologous locus in cattle. This indicated that either the first domain exon (exon 2) of Bubu-DRB has not undergone as much recombination and/or gene conversion as in cattle alleles, or Bubu-DRB may be more ancient than BoLA-DRB3 alleles. Phylogenetic analysis of DRB alleles from Bubalus, Syncerus c. caffer, the Cape buffalo, and domestic cattle demonstrated transspecies polymorphism. Water buffalo contained two alleles of DRA that differed from each other in two amino acid positions, including one in the PBS (alpha22) that was also shared with Anoa depressicornis, the anoa. Discovery of variation in DRA was surprising as the first domain of DRA is a highly conserved polypeptide in mammals in general and especially in ruminants, where no other substitution in PBS was seen.

Alleles↗
PubMed2001

Cattle MHC genes DOA and DOB: sequence polymorphisms and assignments to the class IIb region.

In a study of the genetic polymorphism of the second exons of the cattle DOA and DOB genes, two and four allelic variants were detected, respectively. In the predicted amino acid sequence, the DOA polymorphism corresponded to variation at the respective residue position, whereas the nucleotide substitutions in the DOB gene were non-informative. PCR-RFLP assays were developed for DOA and DOB typing, and both loci were genetically mapped to the BoLA class IIb region by linkage analysis in the International Bovine Reference Panel. The single nucleotide polymorphisms detected in the BoLA-DOA and -DOB genes enable these loci to be used as markers in genetic trait analyses.

Alleles↗
PubMed1979

The production and analysis of antilymphocyte sera following pregnancy and skin grafting of cattle.

This paper presents evidence to show that high titre antilymphocyte sera can be prepared more easily by skin grafting than from parous sera. It also shows that it is possible to analyse complex antilymphocyte sera by absorption with lymphocytes to produce working reagents. Following the 1 International BoLA Workshop the genotype of some of the animals used for skin grafting was ascertained and it was found that in each case where the resulting serum had been studied the main antiserum specificity that had been produced reacted with one of the BoLA specificities present in the skin donor.

Animals↗
PubMed1988

Interspecies cross-reactivity of bovine lymphocytotoxic sera with pig lymphocytes.

Forty-three bovine BoLA antisera were tested on pig lymphocytes by a microlymphocytotoxicity test. Twenty-five were found to be cytolytic. Fifteen sera detected the A blood group antigen on porcine lymphocytes but showed no reaction with the J antigen on bovine lymphocytes. Six BoLA reagents reacted with all pig cells tested. Cross-reactions with SLA antigens were observed in only four sera, the highest correlation being recorded with SLA-W7 (r = 0.87). Bovine alloantisera are not of value for SLA typing.

Animals↗
PubMed1990

Variation in T cell responses to ovalbumin in cattle: evidence for Ir gene control.

Genetic control of immune responsiveness in cattle was investigated using an antigen-dependent T cell proliferation assay in vitro. Bovine T cell proliferative responses to ovalbumin were dependent upon major histocompatibility complex (MHC) class II molecules. Responses of an unrelated panel of animals to a limiting concentration of ovalbumin after a single immunization were compared. Two discrete patterns of response were observed. One group of animals had low or non-responses which were not significantly different from the preimmune levels. Another group of animals showed significant responses. After a second immunization the majority of low responders remained low responders. There was no significant correlation between bovine MHC class I BoLA haplotype and magnitude of response within this group of unrelated animals. However, the magnitude of the T cell responses by two half-sib family groups segregated with BoLA haplotypes inherited from the sire. In contrast no significant correlation with antibody responses in vivo could be demonstrated. We suggest that the observed variation in T cell response is linked to bovine MHC class II immune response (Ir) genes.

Animals↗
PubMed1990

Linkage relationships among 20 genetic markers in cattle. Evidence for linkage between two pairs of blood group systems: B-Z and S-F/V respectively.

Five bovine paternal half-sib pedigrees for a total of 527 individuals were typed for six blood group systems: A, B, F/V, L, S, Z; for nine biochemical polymorphisms: ADA, MPI, PGM-3(slow), NP, Gc, Pi2, Tf, Ptf1 and Ptf2; and for restriction fragment length polymorphisms at five autosomal loci: Tg, GH, LDLr, BoLA-DQ and BoLA-DY. Two of the pedigrees were informative for segregation at the 'muscular hypertrophy' locus, and one was informative at the coat colour determining 'roan' locus. Linkage analysis was performed between all markers. Linkage was demonstrated between the S and F/V blood group systems (z = 3.11), adding one locus to the previously identified linkage group VII (LGVII) [Pi-2 and S], the most likely order being Pi2-S-F/V with maximum likelihood recombination rates of 0.208 and 0.211. Also shown to be linked were the blood group systems B and Z (z = 5.7, theta = 0.245). We confirmed the observation previously made by Andersson et al. (1988) of a high recombination rate between class II genes DQ and DY, suggesting either a larger physical distance between those genes than expected from comparative data, or the presence of a 'recombinational hotspot' in the bovine major histocompatibility complex. No linkage was found either with the 'muscular hypertrophy' locus, or with the 'roan' locus. However, these two loci could be excluded from respectively 1.7 and 2.5 Morgans of the bovine genome.

Animals↗
PubMed1990

The relationship between bovine major histocompatibility complex class II polymorphism and disease studied by use of bull breeding values.

The predictive value of class II DQ and DYA polymorphisms of the bovine major histocompatibility (MHC) complex (BoLA) for the incidence of disease in dairy cattle was estimated in a sample of 196 progeny-tested AI bulls of the Swedish Red and White breed. The BoLA DQ and DYA types of the bulls were determined by analysing restriction fragment length polymorphisms (RFLPs). Breeding values of bulls for clinical mastitis, all diseases including clinical mastitis and diseases other than clinical mastitis were used as measures of disease resistance or susceptibility. The relationship between MHC polymorphism and bull breeding values for disease resistance was evaluated statistically by linear regression analysis. A significant association between the haplotype DQ1A and susceptibility to clinical mastitis was revealed. No other DQ haplotype nor the DYA locus has a significant effect on any of the disease traits studied.

Animals↗
PubMed1993

Isolation, characterization and evolution of ovine major histocompatibility complex class II DRA and DQA genes.

Four full-length ovine major histocompatibility complex (MHC) class II A cDNA clones coding for new alleles of DRA, DQA1 and DQA2 genes were isolated from two ovine lambda gt10 cDNA libraries. The derived amino acid sequences of these clones resemble class II A molecules from other species in both size and structure. Restriction fragment length polymorphism analysis, using an Ovar-DRA probe on DNA from Merino and Romney sheep revealed only limited polymorphism in contrast to the high levels of polymorphism revealed by Ovar-DQA probes. Comparison of the predicted amino acid sequences for the three ovine A genes with class II A genes from five other species revealed that the most variable region of the molecule is the signal peptide. Although virtually every amino acid site shows variation, within or between species, there are some blocks of highly conserved residues. Within gene comparisons of nucleotide differences reveal that the greatest number of changes is found between the alleles of Ovar-DQA1 and -DQA2 genes and the least between Ovar-DRA1 alleles. Phylogenetic analysis of class II A sequences from several species place DRA and DQA genes on two distinct branches, with Ovar-DRA1 and BOLA-DRA, and Ovar-DQA1 and BOLA-DQA being most similar on their respective branches.

Alleles↗
PubMed1996

Mapping economic trait loci for somatic cell score in Holstein cattle using microsatellite markers and selective genotyping.

Marker-assisted selection (MAS) uses genetic marker genotypes to predict an animal's production potential and will provide additional selection information for progeny testing. With the discovery of highly polymorphic microsatellite markers, the tools now exist to begin the search for economic trait loci (ETL), which is the first step toward MAS. The objective of this study was to identify ETL for somatic cell score in an existing Holstein population. Using the granddaughter design, sons from seven grandsire families were genotyped with 20 autosomal microsatellites from five chromosomes (4, 8, 13, 17, 23), with an emphasis on chromosome 23, which is the location of the bovine major histocompatibility complex (BoLA). Selective genotyping was used to reduce the number of genotypes required, in which the 10 highest and 10 lowest sons from the phenotypic distribution curve were tested (140 sons in seven families). One marker (513), located near BoLA, showed evidence of an ETL in three of five polymorphic families. Additional sons were genotyped from the five families to estimate the effect and to compare selective and 'complete' genotyping. Both methods detected an ETL at marker 513, but in different families. This study provides evidence of the usefulness of microsatellite markers and the granddaughter design in the detection of ETL; however, additional markers need to be evaluated to determine the usefulness of selective genotyping. Based on the results from the 20 studied markers, the most likely position of a somatic cell score ETL lies near marker 513, located on chromosome 23.

Alleles↗
PubMed1984

A histocompatibility barrier to immunization against East Coast fever using Theileria parva-infected lymphoblastoid cell lines.

Histocompatibility may be a barrier to the infection of cattle when Theileria parva parva-infected tissues or in vitro cultured macroschizont-infected lymphoblastoid cell lines are used for immunization. By inoculating 10(3) and 10(5) infected cells into autologous recipients infection was achieved and immunity engendered. Cell lines inoculated into BoLA matched recipients did not produce patent infections but some recipients developed antibodies to the parasite and 3/5 were immune to challenge. No evidence of infection or immunity was found in BoLA half matched or mismatched cattle. This result suggests that there is an histocompatibility barrier to infection using T. p. parva-infected lymphoblastoid cells.

Animals↗