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Biomedical subjects

R L Spooner

Publications and source records attributed to R L Spooner.

At least 73 records · Page 4Linked to original sources
PubMed1987

Bovine alloreactive cytotoxic cells generated in vitro detect BoLA w6 subgroups.

Alloreactive cytotoxic T cells (CTL) were generated in mixed lymphocyte culture against cells bearing subgroups of BoLA w6, as well as in BoLA w4, w10 and w16. Primary cultures were restimulated at weekly intervals with irradiated stimulator cells and tested in a 51Cr-release assay with target cells derived from Theileria annulata-infected cell lines. Generation of CTL was accelerated in animals that had been previously primed in vivo by skin grafting. CTL were generated that were specific for BoLA w6 subgroups and not w6. With w6.1 the specific killing was significant at the 5% level, and with w6.2, 6.3 and 6.4 it was significant at the 0.1% level. Where CTL were potentially generated against two BoLA-A locus allele products at the same time (i.e. with heterozygous stimulator cells), one of which was a w6 subgroup, there was similar CTL activity against both products when w6.4 and w16 or w6.1 and w4 were the combinations involved. In two generations against w10 and either w6.1 or w6.2 there was significantly more killing of w10-bearing targets than those with the w6 subgroup.

Animals↗
PubMed1986

Use of bovine lymphocyte antigens in diagnosis of parentage.

Lymphocyte antigens controlled by alleles at the BoLA-A locus were used to indicate which of two bulls could be eliminated as the sire in 18 cases of disputed parentage. The use of bovine lymphocyte antigens (BoLA) significantly increased the exclusion probability over that of the standard red cell and electrophoretic techniques.

Animals↗
PubMed1986

Possible association of antibody responses to human serum albumin and (T,G)-A--L with the bovine major histocompatibility complex (BoLA).

Antibody responses to human serum albumin (HSA) and (T,G)-A--L were determined in 130 young bulls in Norway and the BoLA types of the bulls were defined. Significant associations of some BoLA antigens with immune responsiveness were shown, indicating the likely existence of an immune response (Ir) region linked to the BoLA class I antigens. High response to HSA seems to be a dominant trait. BoLA w2 showed an association with low response to HSA. This may reflect the effect of a specific MHC-associated immune suppressor gene.

Aging↗
PubMed1985

Bovine alloreactive cytotoxic cells generated in vitro: target specificity in relation to BoLA phenotype.

Cytotoxic cells of bovine origin were generated in primary MLC using stimulator cells of BoLA w8/w11 phenotype. Bovine lymphoblasts transformed by the protozoan parasite Theileria parva parva acted as target cells in studies of the specificity of cytotoxicity. When responder cells in MLC did not share w8 or w11 with stimulator cells, cytotoxicity was evident with all targets bearing w8 or w11, or both, and was almost entirely restricted to these products of the BoLA-A locus. When responder and stimulator cells shared both w8 and w11, cytotoxicity was also generated. Whether this was specific for the products of other putative Class I loci in cattle, or for the products of a Class II region, remains to be determined. These results suggest that the determinants recognized by appropriately generated bovine alloreactive cytotoxic cells are identical with, or closely related to, determinants characterized by BoLA w8 and w11 defining alloantisera.

Animals↗
PubMed1984

A method for freezing bovine lymphocytes.

A simple two-stage technique for preserving bovine lymphocytes is described. Lymphocytes from animals chosen at random were used. The experiments indicate that the optimum temperature for freezing and the optimum concentration of dimethylsulphoxide (DMSO) as cryoprotectant were in the range -29 degrees C to -31 degrees C and 17.5% to 20% respectively. These concentrations of DMSO are much greater than those reported in most other studies.

Animals↗
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↗
PubMed1984

Cross reaction of monoclonal antibodies to human MHC class I and class II products with bovine lymphocyte subpopulations.

Peripheral blood lymphocytes (PBL) from cattle have been separated into T & B cell subpopulations using a panning technique. These T and B cell preparations have then been tested by direct and indirect complement mediated cytotoxicity tests with a series of monoclonal antibodies (Moabs) reacting with HLA class I and class II products. The anti-class I monoclonals were monomorphic or non-reactive and where reactive killed both B and T cells. The anti-class II monoclonals reacted only with B lymphocytes. There was no relationship between their reactivity pattern and any BoLA specificity.

Animals↗
PubMed1983

Culling and wastage in dairy cows in East Anglia.

A culling survey in 80 Friesian dairy herds in East Anglia over four years investigated the age at, and reasons for, disposal or death. Failure to conceive was the most important reason except in very old animals. Low production was the second most common reason, culling being particularly heavy in the first two lactations. Mastitis was the major disease influencing wastage and increased with age until the sixth lactation. The percentage of culls for multiple reasons increased with age. There was a high proportion of young animals in most herds and the median lactating life of cows was about three years, equivalent to three lactations. Considerable variation in herd life demonstrated that there was substantial scope for improving herd longevity. Long living herds culled fewer animals for breeding problems in the early lactations and for mastitis in the later ones, enabling more animals to be culled as surplus and for production factors.

Age Factors↗
PubMed1983

Occurrence of cytotoxic antilymphocyte antibodies in sheep.

An earlier report that there is a high incidence (50 to 60 per cent) of cytotoxic antilymphocyte antibody in the sera of parous ewes is confirmed. This antibody is directed against paternally inherited antigens of the fetus. Antibody could be detected pre partum in four out of 34 primiparous ewes. However, there was no strong association between parity and the incidence of antibody. Antibody was also found in three out of 10 older rams which implies that pregnancy is not the only stimulus for antibody production.

Animals↗
PubMed1983

Cell-mediated cytotoxicity in Theileria annulata infection of cattle with evidence for BoLA restriction.

Recovery of calves from tropical theileriosis was accompanied by the disappearance of macroschizonts from lymph nodes and the appearance of cytotoxic cells in the blood and lymph nodes. Acute, fatal disease was associated with incremental parasitosis and parasitaemia and, in general, an absence of detectable cytotoxic cells in the blood or lymph nodes. After recovery from infection, calves were resistant to challenge. Challenge with sporozoites was followed sometimes by an immediate reappearance or by a later peak, or sometimes by twin peaks of cytotoxic cells but macroschizonts were not detected. Histocompatibility (BoLA) typing indicated that calves produced two sequential populations of cytotoxic cells during recovery from primary infection with Theileria annulata. The expression of lysis by the first appeared to be BoLA restricted. In contrast, both the peaks of lysis manifest after challenge appeared to be BoLA restricted. Results suggest that BoLA restricted cells are established in the immunological memory and are probably analogous to cytotoxic T cells, while non-BoLA restricted cytotoxic cells are natural killer like cells. The results suggest a role for cytotoxic cells in recovery from primary infection, in the inhibition of proliferation of macroschizonts which evade mechanisms of acquired resistance and in the lysis of macroschizont infected cells deriving from challenge sporozoites which have evaded serum-mediated inhibition.

Animals↗
PubMed1982

A method for freezing sheep lymphocytes prior to cytotoxicity testing.

The two stage freezing technique was adapted for use with sheep lymphocytes. Parameters investigated were lymphocyte concentration, composition of thawing medium and DMSO concentration. The main difference between this and earlier published techniques is the use of a high DMSO concentration (17%). The technique adopted was both simple and reliable. It consistently gave lymphocyte viabilities of 95% or more in thawed cell suspensions. The procedure is apparently without effect on lymphocyte antigen expression and thus appears very suitable for use in microlymphocytotoxicity tests.

Animals↗
PubMed1981

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.

Alleles↗
PubMed1981

Lymphocyte antigens in sheep.

This paper describes the detection of 13 lymphocyte antigens in sheep. The results obtained from family studies are consistent with the hypothesis that at least 12 antigens are under the control of a single genetic system. The distribution of antigens in the population suggests that the system contains two loci. The 13 antigens were compared with those previously reported. Only one additional specificity was found.

Animals↗
PubMed1981

Analysis of BoLA w6. Evidence for multiple subgroups.

BoLA w6 is one of 16 specificities agreed upon at the 2nd International BoLA Workshop and many laboratories have produced sera reacting with this specificity. This paper presents evidence for at least four sub-groups in w6. Three Edinburgh sera showing identical reaction patterns in the 1st and 2nd BoLA workshops have been studied by absorption. One serum contained a single antibody population reacting with an epitope common to all w6 positive cells. The other two contained antibodies against the same common epitope, antibodies to epitopes on four sub-groups and an antibody reacting only with one subgroup w6.1. Another Edinburgh serum contained two populations of antibodies. One reacting with the common epitope and one with an epitope on two or possibly three subgroups. Immunisation between w6 positive individuals produced antisera to two subgroups without producing antibodies to common epitopes. At least two additional subgroups are likely to exist. These results indicate the presence of specificities unique to individual subtypes coupled with epitopes common to some and all w6 subgroups.

Animals↗
PubMed1980

Electrophoretic mobility of N- and C-terminal monoferric fragments of bovine transferrin phenotypes AA, D1D1, D2D2, and EE, and N-terminal amino acid sequences.

Iron-saturated bovine transferrins A, D1, D2 and E were cleaved by trypsin yielding monoferric fragments. The N-terminal fragments (F) of transferrins A and D2 had identical mobility in cellulose acetate electrophoresis, that of transferrin D1 a slower mobility, and that of E a still slower mobility. The C-terminal fragments (S) gave multiple bands which were essentially identical in the case of transferrins A, D1, and E, but of slower mobility in the case of transferrin D2. All four variants had identical N-terminal amino acid sequences. The electrophoretic mobility of the C-terminal fragments was reduced by neuraminidase treatment, but the N-terminal fragments were unaffected. The four transferrin variants therefore appear to be made up from three electrophoretically distinguishable N-terminal halves and two C-terminal halves. The feature responsible for the electrophoretic double banding of homozygous bovine asialotransferrins is consistently associated with the C-terminal half of the molecule.

Amino Acid Sequence↗