Biomedical subjects

D Bernoco

Publications and source records attributed to D Bernoco.

At least 37 records · Page 2Linked to original sources

PubMed1988

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.

Animals↗

PubMed1987

Polymorphism of the acetylcholine receptor in the horse.

A cDNA probe to the alpha subunit of the murine acetylcholine receptor was used to demonstrate restriction fragment length polymorphism in an acetylcholine receptor gene in the horse. Three different patterns of polymorphism have been observed with fragment sizes of 4.3 and 2.9 kilobases (kb) (pattern 1), 4.3 and 2.5 kb (pattern 2) and 4.3, 2.9 and 2.5 kb (pattern 1,2). Analysis of a three generation pedigree has suggested that patterns 1 and 2 represent two allelic forms of the gene encoding the alpha subunit of the acetylcholine receptor. These data provide a basis for the examination of the genetic control of neuromuscular function in the horse.

Alleles↗

PubMed1987

Distribution of T and B lymphocytes in mammary dry secretions, colostrum and blood of adult dairy cattle.

The distribution of lymphocyte subpopulations from dry secretions, colostrum and blood from 10 healthy adult Hostein-Fresian cows was studied using the TH21A and B26A mouse monoclonal antibodies (MAb) to adult bovine B and T lymphocytes, respectively. The mammary gland lymphocytes (MGL) were isolated from composite sample of all four quarters by density centrifugation over discontinuous gradient of ficoll-diatrizoate. The peripheral blood lymphocytes (PBL) were purified using the ficoll-thrombin method. Isolated PBL and MGL were analyzed using the two fluorochromes method (TFM) and laser flow cytometry (LFC). The mean viability of isolated PBL and MGL from dry secretions and colostrum after the TFM and LFC were 92.4% +/- 3.2%, 91.4% +/- 6.0% and 87.1% +/- 6.1%, respectively. There was a good correlation between the two MAbs and the percentage of surface immunoglobulin (SIg) positive cells in the peripheral blood using the TFM. The PBL yielded a mean percentage of 21.2% B cells, 66.4% T cells and 9.4% "Null cells" (TH21A+; SIg-). The TFM on MGL from dry secretions and colostrum indicated two distinct patterns (group I and II) of SIg and reactivity to MAb markers (p less than 0.001). The MGL data included in group I and group II were gathered from both colostral and dry secretions. In comparison to the distribution of lymphocyte subsets within peripheral blood the mean percentages of B cells, T cells and "Null cells" in the mammary gland were respectively, 2.8%, 88.1% and 5.4% for group I and 3.5%, 89.0% and 15.1% for group II. In the mammary secretions, the use of SIg alone was not considered to be a good marker for B cells; in four animals a mean percentage of 15.6% (13.9/89.0 X 100) of the mammary gland T lymphocytes were also SIg+. Of the TH21A+ MGL, only 18.8% were SIg+ in group II compared with 34.1% for MGL from group I and 69.3% for the PBL. Marked differences in cell size distribution and cell surface antigen density were found when PBL and MGL from dry secretions were compared by LFC using the B26A MAb. The results of this study demonstrate a difference in the percentages of peripheral blood and mammary gland B and T lymphocytes and confirm previous findings in which the T lymphocytes were found to represent the major subpopulation of lymphocytes in bovine mammary secretions. This may represent an essential event in the adoptive transfer of cellular immunity through the colostrum in cattle.

Animals↗

PubMed1987

Evidence of a second polymorphic ELA class I (ELA-B) locus and gene order for three loci of the equine major histocompatibility complex.

Two antisera, B-442 and R-2046, were produced by immunizing offspring with purified peripheral blood lymphocytes from a parent matched for the ELA-A specificity carried on the unshared haplotype. Absorption analysis demonstrated that these antisera contained at least two families of cytotoxic antibodies, one directed against antigens present on T and B cells, and a second directed preferentially against antigens present on surface Ig positive cells. Immunoprecipitation studies using these antisera demonstrated that both antisera contain antibodies specific for glycoproteins with molecular weights characteristic of class I and class II MHC antigens. In lymphocyte typing tests of unfractionated lymphocytes, only the class I activity was readily detectable since the class II activity killed less than 25% of the cells. Family studies demonstrated that these antisera recognize products of genes linked to the ELA system. Based on two recombinants in an extended family it became apparent that the specificities detected by B-442 and R-2046 are not products of the ELA-A locus, but rather they are products of at least one other locus, defined in this paper as ELA-B. In this family a third recombinant was found between the A blood group system and the ELA-A locus. Based on these three recombinants, the most probable linear relationship of the following genes is: A blood group system/ELA-A/ELA-B.

Animals↗

PubMed1987

The ELY-1 locus controls a di-allelic alloantigenic system on equine lymphocytes.

The ELY-1 locus controls the expression of a polymorphic cell surface antigen of equine lymphocytes which was detected using antibodies generated by alloimmunization with peripheral blood lymphocytes. The ELY-1 antigens were not detected on erythrocytes or platelets by absorption experiments. The two alleles, which have been designated ELY-1.1 and ELY-1.2, are expressed codominantly and appear to constitute a closed system at the population level. In family studies, the ELY-1 antigens segregated as products of an autosomal locus not linked to the major histocompatibility complex (MHC) of the horse. In the complement mediated lymphocyte microcytotoxicity test, antisera to the ELY-1 antigens selectively killed peripheral blood lymphocytes which did not express surface immunoglobulin. The ELY-1 antigens may be useful markers for equine T cells when assayed in this fashion. Three alloantisera were used in immune precipitation of iodinated and solubilized cell surface proteins from peripheral blood lymphocytes. Electrophoresis of the precipitates in sodium dodecyl sulphate (SDS)-polyacrylamide gels demonstrated strong bands in the Mr 180-190K range that were shared in the three different preparations. These results suggest that the ELY-1 allospecificities are expressed on an equine equivalent of the murine T200 molecule.

Alleles↗

PubMed1986

Cytotoxic murine monoclonal antibody recognizing an ovine lymphocyte subpopulation similar to the human OKT4-positive set.

A cytotoxic murine immunoglobulin G2b monoclonal antibody was produced from immunization with ovine thymocytes. It reacts with a monomorphic determinant on ovine lymphocytes. This antibody 11.2 G11 does not react with B cells, lyses 50 to 60% of peripheral blood T cells, and precipitates a single chain protein with an apparent m.w. of 57,000. Its effect on mitogen- and antigen-driven lymphocyte proliferation supports its similarity in the sheep to the OKT4 antibody in humans.

Animals↗

PubMed1986

Evidence for BoLA-linked resistance and susceptibility to subclinical progression of bovine leukaemia virus infection.

The role of the bovine major histocompatibility complex in bovine leukaemia virus (BLV) infection and disease progression was investigated in a herd of Shorthorn cattle (n = 117). The frequency of cows that were seropositive to BLV-glycoprotein antigen was 51%. Twenty-three per cent of the seropositive cows were lymphocytotic. At the herd level, relative resistance to BLV-dependent B-cell proliferation and lymphocytosis among seropositive cows was associated with bovine lymphocyte antigen (BoLA)-DA7, whereas susceptibility was associated with BoLA-DA12.3. These associations were also confirmed at the family level, where BoLA phenotypes were used as haplotypic markers. Among the offspring of one BoLA-heterozygous sire (n = 33), resistance segregated with the DA7 haplotype and susceptibility with the DA12.3 haplotype. In this sire group, maternal transmission of the BoLA-w8 allele was associated with increased susceptibility to B-cell proliferation and lymphocytosis in w8/DA12.3 heterozygotes. These data provide the first evidence that subclinical progression of BLV infection is under the control of the BoLA complex, and suggest that the BoLA system can be used to select for resistance to B-cell proliferation and the development of lymphocytosis in BLV-infected herds.

Alleles↗

PubMed1986

Electrophoretic polymorphism and molecular structure of equine C3.

Plasma or serum samples from 12 Arabian and 181 standardbred horses have been typed using an immunofixation technique to determine electrophoretic polymorphism of equine third complement component (C3). Six distinctly different electrophoretic patterns of equine C3 have been recognized thus far. SDS PAGE analysis of equine C3/anti C3 complexes revealed that the submolecular structure comprised an alpha chain and beta chain of molecular weights approximately 118,000 and 63,000 daltons respectively. The molecular weights of the alpha and beta chains were similar in all electrophoretic variants tested. Family data derived from 73 mares, 21 stallions and 99 offspring suggested that the six electrophoretic phenotypes were inherited by means of three codominant alleles named C3-1, C3-2 and C3-3 at a single autosomal locus.

Animals↗

PubMed1985

Monoclonal antibodies that distinguish bovine T and B lymphocytes.

The specificities of three monoclonal antibodies (MAbs) were investigated using microcytotoxicity, fluorescence microscopy and laser flow cytometry (LFC) techniques. By microcytotoxicity, bovine thymocytes (n = 4) were estimated to be 85% B26A+, 4% TH21A+, and 1% H4+. Nylon wool enriched peripheral blood T lymphocytes (n = 3) were 90% B26A+, 10% TH21A+ and 10% H4+. Adherent B cell enriched fractions (n = 3) were 10% B26A+, 90% TH21A+ and 90% H4+. The two fluorochrome method was used to simultaneously identify lymphocytes that were sIg+ and MAb+. In these experiments, 92% of all sIg+ cells were H4+. An identical result was obtained for TH21A. 85% of all sIg- cells were B26A+. Using LFC, the mean percentages of sIg+, H4+ and TH21A+ PBL (n = 5) were not significantly different. B26A recognized a significantly greater population of cells, equivalent to the expected percentage of T lymphocytes. LFC also revealed two relatively discrete sizes of B26A+ PBL. The larger population overlapped the size range in which sIg+, H4+, TH21A+ PBL were found. The more numerous smaller B26A+ PBL were in a size range in which few sIg+, H4+ and TH21A+ PBL were found. In a study of MAb reactions with PBL of 185 cows, it was shown that in 92% of the animals H4 and TH21A were positively correlated (r = +.93), when H4 and TH21A were negatively correlated with B26A (r = -.94 and r = -.92, respectively). These correlation coefficients indicate a converse relationship between B26A and both H4 and TH21A. The remaining 8% of the animals were heterogeneous in their expression of the H4 and TH21A markers but not the B26A marker. These results provide strong evidence that: 1) B26A is a pan-T lymphocyte MAb in cattle, 2) a small but significant degree of heterogeneity exists in the expression of the epitopes recognized by H4 and TH21A. However, both MAbs recognize all B lymphocytes of most individuals, and 3) using a variety of immunological methods these three MAbs can now reliably be used to assay bovine T and B lymphocytes.

Animals↗

PubMed1985

Specific removal of anti-red cell blood group activity from anti-HLA lymphocytotoxic sera and purification of anti-A and anti-B antibodies with lymphocytotoxic activity.

Lymphocytotoxic antibodies to the red cell blood groups A and B were purified from human sera by elution from synthetic immunoadsorbents (Synsorbs from Chembiomed). The lymphocytotoxic activity of the eluted antibodies was better preserved when elution was carried out at pH 11, whereas it was less stable when elution was performed at pH3. In addition, complete removal of anti-red cell blood group activity from an anti-HLA serum was easily obtained by adsorption on the corresponding Synsorb without loss of anti-HLA activity.

ABO Blood-Group System↗

PubMed1985

Cross-reactivity of a monoclonal antibody with bovine, equine, ovine, and porcine peripheral blood B lymphocytes.

Ficoll-thrombin purified suspensions of bovine, equine, ovine, and porcine peripheral blood lymphocytes were fractionated on nylon-wool columns. The percentages of surface immunoglobulin (SIg+)-bearing lymphocytes in the adherent (B-cell enriched) and nonadherent (T-cell enriched) fractions were determined for individual animals using fluorescein isothiocyanate conjugated species-specific anti-Ig sera. Subsequently, the human leukocyte antigen DR-specific monoclonal antibody, H4, was tested for its ability to recognize a cross-reactive antigen on the fractionated lymphocytes, using the microcytotoxicity technique. The H4 plus complement killed a percentage of lymphocytes equivalent to the percentage of SIg+ lymphocytes in the adherent and nonadherent fractions. In a parallel experiment, a 2 fluorochrome technique was used to visualize bovine lymphocytes that were SIg+ and H4+. Lymphocytes that were SIg+ also stained with ethidium bromide (orange fluorescence) after complement-mediated cytotoxicity. Seemingly, H4 recognizes an evolutionarily conserved major histocompatibility complex encoded class-II-like determinant on the B lymphocytes of cattle, horses, sheep, and swine.

Animals↗

PubMed1984

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.

Animals↗

PubMed1983

Detection of Lewis a antigenic determinants in Chinese medicinal herbs.

Two Chinese medicinal herbs, Leonurus sibiricus L. and Carthamus tinctorius L., were found to have high levels of Lewis a (Lea)-like determinants. The water-soluble extracts specifically inhibited hemagglutination, hemolysis, and lymphocyte cytotoxicity directed against Lea. They did not inhibit Leb nor other specificities detected on lymphocytes, resulting from the interaction of Lewis, Secretor, and ABO systems such as A1Leb and A1Led. The activity was nondialyzable, resistant to boiling and proteolytic enzymes, but was destroyed by periodate. It was suprising that an Lea substance, previously found in human secretions, was also present in flower abstracts.

China↗

PubMed1982

Selective reactivity of sera from alloimmunized sheep and cattle against human T and leukemia cells.

Human B and T lymphocytes from a panel of healthy individuals were tested against serial dilutions of 68 mare, 81 cow, 7 sow, and 87 ewe sera. All the animals had been alloimmunized by pregnancies and/or blood transfusions. Weak correlations with HLA-A, B, C, and DR specificities were found in 20 sera. Twelve other sera, 9 from ewes and 3 from cows, had a strong reactivity against T lymphocytes but weak or no reactivity against B cells, spleen null cells, granulocytes, and platelets, suggesting a non-major histocompatibility complex (MHC) cross-reactivity. They were cytotoxic for most of the cells of malignant proliferative origin tested thus far, including T acute lymphoblastic leukemia (T ALL), common ALL (cALL), acute myeloblastic leukemia (AML), and Sezary cells, but were negative with B lymphoblastoid cell lines and cells from patients with B chronic lymphocytic leukemia (CLL) and chronic myelocytic leukemia (CML). The hypothesis that humans and certain other mammals share a common determinant on T-lineage cells and some malignant cells is advanced.

Animals↗

PubMed1982

Treatment with anti-Ia and antiblast/monocyte monoclonal antibodies can prolong skin allograft survival in nonhuman primates.

Two monoclonal antibodies, one directed against human Ia antigens and the other reactive to both monocytes and blast cells, were evaluated for prolonging skin graft survival in Rhesus monkeys. Various doses of the antibodies were given intravenously until the skin graft was rejected. Compared with a graft survival of five days for untreated control monkeys, five animals receiving anti-Ia had grafts surviving from 13 to 19 days and six animals treated with antiblast/monocyte antibody had grafts surviving from 15 to 22 days. No adverse side effects were seen with treatment with antiblast/monocyte antibodies. However, the dose of anti-Ia antibody was critical in that four monkeys died of anaphylaxis when injected with amounts exceeding 200 microliters of ascites with a titer of 1:10(5).

Animals↗

PubMed1982

Monoclonal antibody against A1 Lewis d antigen produced by the hybridoma immunized with a pulmonary carcinoma.

A monoclonal antibody (CALed) against a human pulmonary squamous cell carcinoma line was cytotoxic to the line but did not react to an autologous B-lymphoblastoid line. Although the antibody was thought to be cancer specific, principally on the basis of this evidence, the antibody actually had the A1 Lewis d (Led) specificity. It reacted with approximately 2% of the random donor T-lymphocytes and with all six lymphocytes from donors who were A1 Led type without reacting to lymphocytes of any other type. The monoclonal antibody reactivity was also absorbed out by A1 Led red blood cells but not by red cells of other types. We conclude that the A1 Led antigen had been synthesized by the pulmonary carcinoma lines but not by the autologous lymphoblastoid line, resulting in disparity for this antigen. Since the combination A1 Led only occurs in 2% of the population, it is difficult to distinguish this type of antibody from tumor-specific antibodies.

Antibodies, Monoclonal↗

PubMed1981

Loss of HLA-C locus specificities from stored lymphocytes and de novo synthesis following incubation at 37 degrees C.

The variable expression of the C locus specificities at the cell surface is a major problem in HLA typing and the phenomenon was clearly documented by the International Cell Exchange Program. In contrast with HLA-A and -B, the C locus specificities are readily lost from cells following storage at room temperature for a few days or in overnight incubation at 37 degrees C in the presence of protein synthesis inhibitors. These specificities can be made to reappear by making the cells metabolize at 37 degrees C for 8 to 20 h in nutrient medium. Sixty-nine per cent of the positive C locus reactions lost after 7-day storage at room temperature were recovered after overnight incubation at 37 degrees C. The reappearance was dependent on protein synthesis since presence of cyclohexamide during incubation completely blocked the recovery. A simple overnight incubation is very useful in enhancing C locus expression on older cells.

Epitopes↗

PubMed1981

Early evaluation of Ia monoclonal antibodies in prolonging non-human primate skin allograft survival.

Monoclonal antibodies (MCA) specific against one subset of lymphocytes (anti-B) were used in treating skin allograft rejection in Rhesus monkeys. Rhesus monkeys were treated daily with intravenous MCA until the skin graft was rejected. The dose of the MCA was adjusted according to the peripheral B-cell counts obtained by rosetting technique as well as by indirect immunofluorescence. We finally achieved a safe dose, though the margin of safety was narrow. We also noted that the B-cell count dropped to a significant degree and that the survival of the skin graft was prolonged.

Animals↗