Joint Report of the Third International Bovine Lymphocyte Antigen (BoLA) Workshop, Helsinki, Finland, 27 July 1986

Summary. Two hundred and eighty-two alloantisera were submitted by 20 participating laboratories from 13 countries and tested against lymphocytes of 1298 cattle. The cell panel consisted of samples from 38 Bos taurus breeds, 11 Bos taurus crossbreeds, 4 Bos indicus breeds, 6 Bos taurus X Bos indicus , and a variety of other crossbred populations. Using a standardized lymphocytotoxicity test, all 17 previously identified BoLA specificities were confirmed. The workshop produced agreement on 16 new lymphocyte alloantigenic specificities. Three of the new specificities behaved as splits of previously identified BoLA specificities. Four of the new specificities behaved as alleles at the agreed BoLA-A locus. Seven new specificities are tentatively assigned to the BoLA-A locus but require further definition. Two new specificities may represent products of a second closely-linked BoLA locus.     

Joint report of the Third International Bovine Lymphocyte Antigen (BoLA) Workshop, Helsinki, Finland, 27 July 1986

Two hundred and eighty-two alloantisera were submitted by 20 participating laboratories from 13 countries and tested against lymphocytes of 1298 cattle. The cell panel consisted of samples from 38 Bos taurus breeds, 11 Bos taurus crossbreeds, 4 Bos indicus breeds, 6 Bos taurus x Bos indicus, and a variety of other crossbred populations. Using a standardized lymphocytotoxicity test, all 17 previously identified BoLA specificities were confirmed. The workshop produced agreement on 16 new lymphocyte alloantigenic specificities. Three of the new specificities behaved as splits of previously identified BoLA specificities. Four of the new specificities behaved as alleles at the agreed BoLA-A locus. Seven new specificities are tentatively assigned to the BoLA-A locus but require further definition. Two new specificities may represent products of a second closely-linked BoLA locus.     

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 1st 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.     

Joint Report of the Fourth International Bovine Lymphocyte Antigen (BoLA) Workshop, East Lansing, Michigan, USA, 25 August 1990

Blood samples from 54 animals were exchanged between 15 laboratories in nine countries to improve and expand BoLA class I and class II typing. A total of 27 out of 33 (82%) of previously accepted BoLA-w specificities were represented within the cell panel. Seventeen new serum-defined BoLA specificities were accepted by the workshop participants, thus expanding the number of internationally recognized BoLA specificities to 50. The large number of new specificities detected resulted from the number of serological reagents used (n = 1139) and the genetic diversity of the cell panel. Confidence derived from the high percentage of agreement between the laboratories on antigen detection (97.3%; r = 0.84) permitted the removal of the workshop (w) notation from 23 BoLA-w specificities and their acceptance as full status BoLA-A antigens. Two new non-BoLA antigens were also detected, one completely included within the red blood cell factor S' (BoLy-S'), whereas a second (BoLy-w1) did not show any association with tested red blood cell factors. A comparison between serological, isoelectric focusing (IEF) and DNA typing for BoLA class II polymorphism was conducted with a subset of workshop cells. Correlation between the three methods was significant for three combinations of alleles. Three other serologically defined class II specificities were correlated with DR and/or DQ restriction fragment length polymorphism (RFLP) types, whereas six additional IEF types were correlated with DR and/or DQ RFLP types (r greater than or equal to 0.50). Several new IEF, DRB, DQA and DQB RFLP patterns were identified. In 46 animals that were typed for BoLA-DR and DQ genes by RFLP analysis, 46 different BoLA haplotypes were tentatively defined. These 46 haplotypes were distinguished by 31 serologically-defined BoLA-A alleles (and 2 'blanks'), 15 DRB RFLP types (plus up to 10 new DRB RFLP patterns) and 23 DQA-DQB haplotypes.     

A genetic study of bovine lymphocyte antigens (BoLA) and their frequency in several breeds

Using sera which defined the BoLA specificities at the two International BoLA workshops (Edinburgh, 1978 and Wageningen, 1980) and the European Regional workshop (Paris, 1979),142 informative matings from 15 bulls have been studied. On the basis of this data, 11 of the 15 internationally agreed specificities and one of the regionally defined specificities behave as if controlled by alleles at a single autosomal locus. Data has not as yet been obtained for the other four internationally agreed specificities which are also believed to be at this locus. — The frequencies of 13 of the internationally agreed specificities and one of the regionally defined specificities have been studied for both sexes in one breed and for a single sex in another five breeds. The other two internationally agreed specificities are very recent and the populations have not been tested for them. The frequencies between sexes within a breed and within sexes between breeds differ significantly.     

Joint report of the Third International Workshop on Lymphocyte Alloantigens of the Horse, Kennett Square, Pennsylvania, 25-27 April 1984

The Third International Workshop on Lymphocyte Alloantigens of the Horse was held on 25-27 April 1984 in Kennett Square, Pennsylvania. Twelve laboratories from five countries participated. The principal purpose of this Workshop was to determine the phenotypic and gene frequencies of the 10 equine lymphocyte antigens (ELA) and a non-ELA lymphocyte antigen, ELY-2.1, in several breeds of horse. A total of 86 alloantisera characterized in previous workshops were tested against lymphocytes from 1179 horses. In addition, several experimental antisera were also tested against the same panel of lymphocytes. As a result of analysis of these data, the Workshop recognized two new equine lymphocyte alloantigens: W11 of the ELA system, and ELY-1.1, an antigen not linked to the ELA system.     

Joint Report of the Fifth International Workshop on Lymphocyte Alloantigens of the Horse, Baton Rouge, Louisiana, 31 October-1 November 1987

Six laboratories participated in the Fifth International Workshop on Lymphocyte Alloantigens of the Horse, testing 132 alloantisera against lymphocytes of 880 horses chosen to represent different families and breeds. Most of the alloantisera were produced by lymphocyte immunization between horses matched at the ELA-A locus. All horses were also tested with antisera contributed to the workshop by participating laboratories which identified ELA specificities A1-A10 and W12-W21. Previously identified workshop specificities ELA-W14, W15 and W19 were accepted as products of the ELA-A locus based on family and population studies by the workshop. Their designations were changed to ELA-A14, ELA-A15 and ELA-A19, respectively. Two new specificities were identified, namely ELA-W22 (W22) and ELA-W23 (W23). Population and family studies indicated that W22 and W23 as well as W13 are products of an ELA locus other than ELA-A. The presence of these specificities was correlated with the presence of certain ELA-A locus specificities, e.g. W13 with A3, W22 with A2 and W23 with A5. However, the association was not complete and W13, W22 and W23 also segregated with other ELA-A specificities in some families. Evidence for recombination was found between the ELA-A locus and the locus or loci encoding these specificities resulting in seven recombinant haplotypes found among the data presented in this workshop. Further studies are required for definitive assignment of the specificities to a class I or class II locus.     

Analysis of alloantisera against bovine lymphocytes. Joint report of the 1st International Bovine Lymphocyte Antigen (BoLA) Workshop

The results and agreements of the 1st international BoLA workshop, held in Edinburgh, Scotland in August 1978, are reported. Most of these concern the results from a comparison test of 249 alloantisera to bovine lymphocytes, the antisera being contributed by 9 laboratories. These sera were compared directly in Edinburgh on a panel of lymphocytes from 130 cattle of 21 breeds. In the micro-lymphocytotoxicity test used 75% of the sera reacted. Sixty eight of these sera were grouped into clusters according to their reaction patterns against the lymphocyte panel. Eleven of these clusters were clearly defined and were given workshop BoLA designations. In addition 22 sera were assigned to subgroups of the agreed clusters. There was no evidence that the method of production of the sera had any effect on their specificity.
Although genetic data was not available, the phenotypes of the test panel of lymphocytes are consistent with the clusters detecting antigens controlled by multiple alleles at a single autosomal locus. It was agreed to name the genetic region where this putative locus is located BoLA (bovine lymphocyte antigen).     

Analysis of alloantisera against bovine lymphocytes. Joint report of the 1st International Bovine Lymphocyte Antigen (BoLA) workshop

The results and agreements of the 1 international BoLA workshop, held in Edinburgh, Scotland in August 1978, are reported. Most of these concern the results from a comparison test of 249 alloantisera to bovine lymphocytes, the antisera being contributed by 9 laboratories. These sera were compared directly in Edinburgh on a panel of lymphocytes from 130 cattle of 21 breeds. In the microlymphocytotoxicity test used 75% of the sera reacted. Sixty eight of these sera were grouped into clusters according to their reaction patterns against the lymphocyte panel. Eleven of these clusters were clearly defined and were given workshop BoLA designations. In addition 22 sera were assigned to subgroups of the agreed clusters. There was no evidence that the method of production of the sera had any effect on their specificity. Although genetic data was not available, the phenotypes of the test panel of lymphocytes are consistent with the clusters detecting antigens controlled by multiple alleles at a single autosomal locus. It was agreed to name the genetic region where this putative locus is located BoLA (bovine lymphocyte antigen).     

Xenoantisera to human DR antigens: Serological and immunochemical characterization

Antibodies to DR antigens were detected using serological and immunochemical tests in sera from rabbits and goats immunized with cultured human B-lymphoid cells mixed with an anti-T-cell xenoantiserum or with partially purified DR antigens. After absorption with human red blood cells, cultured melanoma cells, and/or T-lymphoid cells, DR xenoantisera become specifically cytotoxic to B lymphocytes. Three out of nine sera tested with a panel of T-depleted peripheral lymphocytes and chronic lymphocytic leukemia cells showed correlation with DR alloantisera submitted to the Seventh International Histocompatibility Workshop. Although the correlation coefficients were lower than those obtained with DR alloantisera, the results obtained suggest that DR xenoantisera may recognize allotypic specificities.     

Joint Report of the Third International Workshop on Lymphocyte Alloantigens of the Horse, Kennett Square, Pennsylvania, 25–27 April 1984

Summary. The Third International Workshop on Lymphocyte Alloantigens of the Horse was held on 25–27 April 1984 in Kennett Square, Pennsylvania. Twelve laboratories from five countries participated. The principal purpose of this Workshop was to determine the phenotypic and gene frequencies of the 10 equine lymphocyte antigens (ELA) and a non-ELA lymphocyte antigen, ELY-2.1, in several breeds of horse. A total of 86 alloantisera characterized in previous workshops were tested against lymphocytes from 1179 horses. In addition, several experimental antisera were also tested against the same panel of lymphocytes. As a result of analysis of these data, the Workshop recognized two new equine lymphocyte alloantigens: W11 of the ELA system, and ELY-1.1, an antigen not linked to the ELA system.     

Serological study of BoLA class I antigens

Typing reagents were prepared determining the class I antigens of the main histocompatibility complex in cattle (BoLA). The microcytotoxic test was applied to analyse 450 sera (reagents) obtained from cows postpartum. Testing these sera on the panel of lymphocytes from unrelated animals and calculating mutual correlations of the reactions, we determined 113 groups of similarly reacting sera (clusters) which determine 13 specificities of Class I BoLA complex. The majority of these correspond to the internationally approved BoLA antigens.     

Joint Report of the First International Comparison Test on Swine Lymphocyte Alloantigens (SLA)

The first international comparison test on swine lymphocyte alloantigens (SLA) was held in Helsinki, Finland in July 1986. The results reported were based on a comparison of 157 alloantisera originating from six laboratories. The antisera were tested against a selected panel of 264 lymphocyte samples belonging to four laboratories. The most common breeds in Europe were chosen for this first comparison test (Landrace and Large White). Eighteen of the 31 previously known specificities were confirmed and a new nomenclature was established.     

Mixed lymphocyte culture studies reveal complexity in the bovine MHC not detected by class I serology

The genetic structure of the bovine major histocompatibility complex (MHC) was investigated using the lymphocyte microcytotoxicity test for class I typing and the mixed lymphocyte culture (MLC) assay for class II typing. Using locally produced alloantisera and antisera from the Third International BoLA Workshop, 14 class I BoLA-A locus alleles were identified in the study population, a single herd of approximately 700 Holstein-Friesian cattle. Eleven of these were alleles recognized in the International Workshop and three were new alleles. An MLC titration assay was employed in conjunction with class I typing to define BoLA haplotypes and identify BoLA complex homozygotes. An embryo transfer family consisting of eight full sibling cattle including one BoLA complex homozygote was produced by half sibling mating. Five other BoLA complex homozygotes were subsequently identified in the herd. Six MLC defined class II haplotypes investigated in detail were designated BoLA-D1, D2, D3, D4, D5 and D7. BoLA-D1 was associated with the class I specificity BoLA-Aw6, D2 with Aw6 and the new class I specificity Ac3, D3 with Aw6 and Aw11, D4 with Aw10, D5 with Aw31 and Aw11, and D7 with Aw20. The discovery of four groups of class I identical-class II disparate haplotypes, and three pairs of class I disparate-class II identical haplotypes indicates the presence of considerable complexity in the BoLA complex that is not detected using class I serology.     

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.     

Alloreactive T-cell recognition of bovine major histocompatibility complex class II products defined by one-dimensional isoelectric focusing

T-cell recognition of bovine MHC (BoLA) class II antigens was investigated in relation to BoLA class II polymorphisms defined by one-dimensional isoelectric focusing (1D-IEF). One-way mixed lymphocyte reactions (MLRs), and allospecific cell lines and clones were used. In general, T-cell responses correlated with the 1D-IEF defined haplotypes (EDF types). However, with MLRs some responses appeared to be associated with BoLA class I differences. All combinations of responder-stimulator pairs produced alloreactive T-cell responses both in MLR and in generation of allolines/clones. Thus allospecific lines and clones were generated to all EDF types tested. Splits in the IEF typing were observed with EDF6 and EDF3, indicating that distinct BoLA class II haplotypes are not necessarily distinguished by 1D-IEF alone. Furthermore, the patterns of reactivity with EDF3 expressing cells were complex with the T-cell specificities splitting EDF3 into several distinct types. Also, in some cases it was clear that more than one T-cell specificity per EDF type was detectable. Thus, allospecific lines and clones provide complementary and additional information to the 1D-IEF typing for polymorphism of the BoLA class II complex. This extra information is particularly important in terms of the functional significance of the BoLA complex for antigen presentation and immune response gene effects.     

Joint Report of the Second International Workshop on Lymphocyte Alloantigens of the Horse, held 3–8 October 1982

The Second International Workshop on Lymphocyte Alloantigens of the Horse was held 3–8 October 1982. At this workshop, the 6 specificities identified at the first workshop were confirmed and an additional 5 new specificities were identified and given workshop nomenclature. Four of the new specificities, products of the ELA locus, were named ELA-W7, W8, W9, and W10. An additional specificity, designated ELY-2.1, is the product of a locus independent of the ELA locus.
Cell isolation methods were compared at this workshop, Technical variation in methods clearly affected reactivity of many reagents. However, when highly selected reagents were used, antigen assignment did not differ regardless of the cell isolation method. Based on the comparison of methods, isolation procedures in which thrombin was used were more effective than those relying on carbonyl iron or slow centrifugation.     

A comparative study of major histocompatibility complex antigens in East African and European cattle breeds

An account is given of the serologically defined class I specificities encoded by the bovine MHC (expressed as the BoLA system) in two populations of African cattle and in European breeds. The BoLA typing was performed using alloantisera raised against tissue antigens of both European and African breeds of cattle. All of the specificities agreed in the first two international BoLA workshops were found in the African cattle, although there were significant differences in the frequency of some specificities between the African and European animals. Many of the European antisera, which are operationally monospecific in Bos taurus cattle, were multispecific in the African animals. Subgroups of two specificities (w8 and w10) were demonstrated. Five new BoLA-A locus alleles were detected by means of antisera raised against alloantigens of African cattle. Two of these occurred at an extremely high frequency in the African populations; one being unique to these cattle. Monoclonal antibodies proved to be useful typing reagents, particularly in the elucidation of subgroups.     

B-Lymphoid cell lines derived fromHLA-D homozygous donors

Multiple lymphoid cell lines were derived from 35HLA-D homozygous donors by EB-viral transformation of B lymphocytes. The expression of Ia-like alloantigens (HLA-DR) was studied by microcytotoxicity and by absorption with alloantisera exchanged through the Seventh Histocompatibility Workshop. B-lymphoid lines expressed the same specificities as normal B lymphocytes. Workshop antisera representing DRw1, DRw2, DRw3, and DRw7 gave well-defined typing patterns with cell lines derived from donors of corresponding D-locus specificities. A more complex reaction pattern was seen for antisera representing DRw4, DRw5, and DRw6. The available reagents could not discriminate between lines from donors homozygous for Dw4, Dw10, or D-KH. All lines studied, except for those from one donor homozygous for a unique D-locus determinant (D-SPO), could be assigned one of the provisional DRw specificities.The advantage of obtaining multiple cell lines from a single donor was evident. One line could not be typed by microcytotoxicity because it was lysed in all human sera tested, and some other lines gave weak cytotoxic reactions. Absorption studies, however, did indicate similar expression of DRw antigens on these lines. The availability of multiple lines from the same donor circumvented these difficulties.     

Comprehensive linkage map of bovine chromosome 11

The results of genotypic data contributed to the International Society of Animal Genetics (ISAG) Bovine Chromosome 11 (BTA11) Workshop are presented. Six laboratories contributed a total of 26 199 informative meioses from 80 loci. Thirty-six loci were typed by at least two independent laboratories and were used to construct a consensus linkage map of the chromosome. The remaining loci were subsequently incorporated into a comprehensive map. The sex-averaged consensus map covered 128.9 cM. The female consensus map was 101.2 cM, while the male consensus map was 129.8 cM. The comprehensive sex-averaged map was 134.2 cM and the average genetic distance between loci was 1.72 cM.