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R R Dietert

Publications and source records attributed to R R Dietert.

At least 73 records · Page 4Linked to original sources
PubMed1985

Chicken developmental antigens: analysis of erythroid populations with monoclonal antibodies.

Fusions were performed between the mouse PAI myeloma cell line and spleen cells from Balb/c mice immunized with intact erythrocytes from 1-day Cornell K-strain White Leghorn chickens. Following single cell cloning, four hybridoma clones were found to secrete erythroid specific monoclonal antibodies. Based on its pattern of reactivity, the antibody (IgG2a, kappa) secreted by clone 10C6 detects a specific avian oncodevelopmental antigen associated with the hematopoietic system: chicken fetal antigen (CFA). Two other clones, designated as 3F12 and 4C2, produced antibodies (IgM, kappa) that recognize another avian developmental antigen: chicken adult antigen (CAA). A fourth clone, 9F9, produced an antibody (IgM, kappa) that reacts with all peripheral erythrocytes from both Japanese quail and chicken regardless of age. Clone 10C6 antibody apparently detects an erythrocyte specific (ES) determinant of CFA associated with determinant #8 while antibodies of clones 3F12 and 4C2 recognize a chicken specific determinant of CAA. Analysis by complement mediated microcytotoxicity indicated that the epitopes detected by 10C6 vs 3F12 and 4C2 antibodies were expressed on erythrocytes in a reciprocal fashion during development. Furthermore, strain variations in the incidence of erythrocytes carrying these epitopes were observed. The usefulness of these monoclonal antibodies for the study of erythroid populations is discussed.

Aging↗
PubMed1985

Autoanti-thyroglobulin production in obese chickens: influence of age and sex as measured by ELISA.

The kinetics of serum autoantibody production against thyroglobulin (Tg) was examined in two strains of chicken using an enzyme-linked immunosorbant assay (ELISA). Both strains are homozygous for the B13 haplotype. The OS strain develops spontaneous autoimmune thyroiditis at several weeks of age while the Sp. C strain, which serves as the control for the OS strain, has virtually undetectable autoantibody levels as determined by hemagglutination assay (HA). Serum autoantibody levels in both strains were monitored bi-weekly from 6 through 14 weeks of age post-hatching, using both the ELISA and HA techniques. With the more sensitive ELISA, absolute serum autoantibody concentrations were determined and both the Sp. C and OS strains were found to have readily detectable serum autoantibodies against Tg; however, the OS did have significantly higher autoantibody levels than the Sp. C strain. In the latter strain, autoantibodies increased significantly with age while the pattern was somewhat reversed in the OS strain. The ELISA revealed that the decline of Tg autoantibodies with age in the OS strain was restricted primarily to males, with females maintaining constant levels of autoantibodies. In contrast, the HA detected only the differences in autoantibody levels between the OS and Sp. C strains.

Aging↗
PubMed1984

Molecular characterization of fetal antigens on red blood cells of chickens, Japanese quail, and quail-chicken hybrids.

The molecular nature of chicken fetal antigen (CFA) and quail fetal antigen (QFA) was studied on embryonic red blood cells (RBCs) of the chicken, the Japanese quail, and the quail-chicken hybrid. Specific immunoprecipitation of radiolabeled membrane proteins followed by electrophoretic separation and autoradiography were used to identify the protein molecules carrying these fetal antigens. CFA was found on molecules of 24, 50, 88, 99, 130, 170, and 220 kd (kilodaltons) in the chicken and hybrid and on molecules of 24, 50, 99, and 170 kd in the Japanese quail. Similarly, quail fetal antigen was associated with 24-, 50-, 99-, and 170-kd molecules in the quail and hybrid and was not detected in the chicken. Partial proteolytic digestion of the 50- and 170-kd molecules isolated from RBCs of all sources showed remarkably similar peptide patterns. Likewise, two-dimensional separation of the CFA-positive and QFA-positive 50-kd molecules from quail RBCs revealed a similar pattern of at least nine isomorphic variants. Sequential depletions of quail embryonic RBC extracts with either anti-CFA or anti-QFA followed by immune precipitation with the reciprocal antiserum suggested that most of the cell surface proteins carrying QFA also have CFA on the same molecules. It is suggested that specific glycosylations of a variety of distinct molecular weight proteins determines the antigenic phenotype characterized as "fetal antigens."

Animals↗
PubMed1984

Avian peritoneal exudate cells: a comparison of stimulation protocols.

The influence of different stimulation protocols on the induction of peritoneal exudate cells (PECs) and adherent cells, and on the percentage of different adherent cell types was examined in the chicken and Japanese quail. The results suggest that different protocols may be selected to maximize isolation of specific PEC populations for immunological studies. In the chicken, starch, peptone, glycogen, and Sephadex G-40 were all equally effective and superior to saline in generating PECs. While a single injection of Sephadex produced the highest yield of adherent cells with a maximum percentage of macrophages, repeated injections of Sephadex led to dramatic increases in non-adherent PECs (lymphocytes). In contrast, a single injection of starch was optimum for generating non-macrophage adherent cells (primarily heterophils). Since responses of the Japanese quail to stimulation with starch and saline were similar to those observed for the chicken, it is suggested that these protocols may be generally applicable for use with avian species.

Animals↗
PubMed1984

Differentiation properties of avian tumor cell lines: analysis using chicken fetal antigen and other markers.

Three avian lymphoblastoid tumor cell lines were compared for the expression of the serologically complex cell surface antigen, chicken fetal antigen (CFA), and other properties associated with differentiation. Two Marek's disease cell lines (CU-12 and CU-36) and a cell line associated with lymphoid leukosis (CU-10) were all found to differ qualitatively in the expression of CFA. While both Marek's disease cell lines exhibited overall phenotypes similar to those of T-lymphocytes, the lymphoid leukosis cell line possessed characteristics in common with either immature lymphocytes or cells of the reticuloendothelial system. The specific patterns of CFA expression on these lymphoid tumor cells may be related to the particular level of differentiation blockage during tumorigenesis as has been proposed for erythroblastosis. The lymphoid leukosis cell line exhibited a pattern of CFA expression that would not distinguish between the possibility of differentiation blockage versus retrogenic expression. Since CFA is known to be associated with a series of cell surface glycoproteins, the exact relationship between individual molecules, the level of lymphoid differentiation, and changes associated with tumorigenesis may now be examined.

Animals↗
PubMed1983

Monosaccharides define two immunodominant structures of chicken fetal antigen.

Chicken fetal antigen (CFA) is an oncodevelopmental antigen associated with hematolymphoid development and differentiation. The immunodominant structures of two CFA determinants were characterized by hapten inhibition of microcytotoxicity (HIM) and were found to be defined by specific monosaccharides. CFA determinants 5 and 11 were effectively (greater than 50%) inhibited by D-mannose and D-glucose, respectively. Therefore, these carbohydrate residues, or closely related structures, are proposed as the immunodominant structures for these antigenic determinants. Implications of these results vis à vis the developmental control and biological role of CFA are discussed.

Animals↗
PubMed1983

Quail fetal antigen (QFA): identification and comparison with chicken fetal antigen.

Quail fetal antigen (QFA), an analogous hematopoietic antigen to chicken fetal antigen (CFA), was identified and shown to be a developmental antigen on the blood cells of Japanese quail and other avian species. Rabbit antiserum against 14-day embryonic quail red blood cells (RBCs) was specifically adsorbed to achieve fetal specificity and to eliminate any cross reactivity with the CFA system. Complement-mediated microcytotoxicity and hemagglutination assays were used to detect the presence of QFA on hematopoietic cells. QFA was found on 100% of the peripheral RBCs from 10-day quail embryos but incidence of the antigen gradually declined with increasing development. Complete loss of QFA from RBCs occurred just prior to sexual maturation between 31 and 42 days of age. No qualitative differences in erythroid expression of QFA were observed during development; however, RBCs from both embryonic duck and interspecific quail- chicken hybrids reacted with R-anti QFA. Like CFA, quail fetal antigen was associated with lymphocytes, particularly those from primary lymphoid organs. Similarities in the developmentally controlled tissue distribution of QFA and CFA suggest that developmental hematopoietic antigens are a common feature of avian species and are useful cell surface markers for studies of development and differentiation.

Age Factors↗
PubMed1983

Developmental expression of chicken fetal antigen on peritoneal macrophage: implications for hematopoietic differentiation.

Chicken fetal antigen (CFA) was demonstrated by both complement-mediated microcytotoxicity and immunofluorescence to be present on the cell surface of activated peritoneal macrophage. While CFA-positive macrophage were observed in young birds, the antigen was absent from adult macrophage. A comparison of cell surface CFA on macrophage, lymphocytes, and erythrocytes indicated that unique subsets of CFA determinants are characteristic for each differentiation lineage. As a result, CFA can serve as a cell surface marker for differentiation-specific gene expression. Since CFA determinants are known to be at least partly defined by carbohydrates, it is suggested that hematopoietic heterogeneity for CFA may result from lineage-specific carbohydrate microheterogeneity.

Animals↗
PubMed1983

Hematological toxicology following embryonic exposure to aflatoxin-B1.

The influence of embryonic exposure to aflatoxin-B1 (AF-B1) upon the erythroid system of the maturing chicken was examined using a variety of assays. Since the chick embryo is known to possess mixed-function oxidase activity, this animal serves as an excellent model system for studies of human fetal toxicology. AF-B1 (0.1 microgram) was administered to either 6- or 12-day embryos by the air sac method. This level of AF-B1 was highly mutagenic and was found to induce an average of 10.6 sister chromatid exchanges (SCEs) per cell compared with 1.8 SCEs per cell for the acetone control solvent. Despite selection against treated embryos through acute and chronic embryonic toxicity, hatched chicks from AF-B1 treatment groups exhibited erythroid anemia when compared to the acetone controls. Cell count, hematocrit, and hemoglobin concentration were all significantly reduced in the 12-day AF-B1 treatment groups compared with controls. Both sexes were equally affected. While the number of peripheral erythrocytes was reduced following exposure to AF-B1, the differentiation status of erythrocytes was apparently unaltered. Mean cell volume, percentage of circulating reticulocytes, and incidence of an erythroid differentiation marker, chicken fetal antigen, were parameters in which no treatment effects were observed. An apparent maturation effect was noted since adult hematocrits were similar between control and treatment groups. Possible explanations for this age effect are discussed. The ability to detect significant posthatch erythroid toxicity following embryonic exposure to mutagenic levels of AF-B1 suggests the importance of this general approach to perinatal carcinogenic evaluation.

Aflatoxin B1↗
PubMed1982

Chicken fetal antigen: association with lymphoid development and differentiation.

Rabbit antisera capable of detecting chicken fetal antigen (CFA) was prepared against 1-day chick red blood cells (RBCs) and made specific by exhaustive adsorption with adult chicken peripheral RBCs (PRBCs) from the same strain. Microcytotoxicity was used to study the incidence of CFA on lymphocytes obtained from several organs at different developmental stages in the chicken. Lymphocyte-associated CFA (LA-CFA) determinants and erythrocyte-specific CFA (ES-CFA) determinants were distinguished through the use of adsorption analysis. The high incidence of CFA-positive lymphocytes found in the fetal bursa and thymus was not equaled in the peripheral organs of the spleen, cecal tonsils, and gland of Harder. CFA expression on adult lymphocytes was restricted to the thymus and peripheral blood. It is suggested that these cells may represent a subpopulation of T lymphocytes. Adult spleen, cecal tonsils, and gland of Harder were virtually devoid of CFA-bearing lymphocytes. At fetal developmental stages when greater than 94% of the bursal B cells were CFA-positive, few, if any, of the highly differentiated Harderian B cells possessed CFA. It is suggested that LA-CFA expression is dependent upon B cell differentiation and/or the bursa (central) vs gland of Harder (peripheral) microenvironment. The pattern of CFA expression on bursacytes is discussed in light of the properties of age resistance and bursal-dependent target cells associated with virally induced lymphoid leukosis.

Aging↗
PubMed1982

Characterization of a genetically segregating determinant of chicken fetal antigen by a new hapten inhibition of microcytotoxicity (HIM) assay.

The immunodominant structure of a chicken fetal antigen (CFA) determinant was investigated using a new hapten inhibition of microcytotoxicity (HIM) assay. This HIM assay employing avian erythrocytes was shown to be a highly sensitive, economical technique and was verified in a separate experiment using bovine serum albumin (BSA) coupled to Japanese quail peripheral red blood cells (QPRBCs). Inhibition of microcytotoxicity was measured following preincubation of 1 microliter of specific antiserum with 1 microliter of antigen solution. A concentration of 21.1 nM BSA was found to produce effective (50%) inhibition of microcytotoxicity of BSA-coated QPRBCs. The percentage cytotoxicity was determined by estimating the proportion of intact RBCs to free nuclei using an inverted microscope. Staining of the reaction mixtures was not required for scoring. Application of this technique for the characterization of immunodominant structures was demonstrated by the analysis of a CFA determinant known to exhibit both developmental expression and genetic segregation. R-anti-CFA-10 was effectively inhibited only by D-galactose (35.5 mM) and the galactose-containing sugars lactose (28.2 mM), raffinose (29.9 mM), and stachyose (39.8 mM). Implications of the carbohydrate nature of CFA are discussed.

Animals↗
PubMed1981

Chicken fetal antigen: example of an antigenically complex oncodevelopmental membrane glycoprotein.

CFA is a complex onco-developmental membrane marker system that is being investigated at the cellular, molecular, genetic and functional levels. CFA appears to be a family of genetically-determined carbohydrate side chains attached to a membrane-bound polypeptide chain. Unique combinations of the thirteen serologically detectable CFA determinants are expressed on erythroid and lymphoid cells of all avian species tested. Whether or not CFA determinants are hematopoietic specific markers remains to be established. The CFA determinants are proving to be useful membrane markers for the study of normal as well as neoplastic hematopoietic cellular differentiation. The probability that CFA determinants are differentiation-stage-specific markers for cells of both the erythroid and lymphoid series coupled with the observation that one of the CFA determinants acts as a cell membrane binding site for an arbovirus makes this antigen system a valuable tool for studying the cellular differentiation blockage hypothesis of neoplasia.

Aging↗
PubMed1980

Developmental changes in the presence of specific chicken fetal-leukemic antigen determinants in the chicken, Japanese quail, and the interspecific hybrid.

The pattern and timing of expression of chicken fetal-leukemic antigen (CFA) on peripheral red blood cells (RBCs) is reported for specific periods of postembryonic development in chickens, Japanese quail, and quail-chicken hybrids. Individual CFA determinants were lost from the peripheral RBCs of chickens and hybrids at specific times of development. The sequential pattern of phasing in these sources suggests that at least some of the CFA determinants may be expressed independently on the cell surface. In addition, the time of phasing for each determinant may represent a developmentally-controlled change in the internal or external environment of the differentiating erythrocyte. In contrast, three CFA determinants appeared to be lost simultaneously, or over a short period of time, from the RBCs of Japanese quail. This phasing event appears to occur approximately one week prior to the onset of egg production. In the interspecific hybrid, the same three CFA determinants appeared to be independent with regard to the periods in which they were expressed on peripheral RBCs.

Animals↗
PubMed1979

Demonstration of chicken fetal antigen (CFA) on normal splenic lymphocytes, Marek's disease lymphoblastoid cell lines and other neoplasms.

Chicken fetal antigen (CFA) was detected on normal splenic lymphocytes and a direct relationship was observed between the percentage of CFA-positive cells and the age of the donor. The fetal antigen was also detected on lymphoblastoid tumor cells and cell lines induced by known avian oncogenic viruses (Marek's disease virus and avian leukosis virus), and on spontaneously occurring adenocarcinoma cells. The fetal antigen appears to be distinct from Marek's disease tumor-associated surface antigen.

Adenocarcinoma↗
PubMed1979

Genetic regulation of CFA expression in interspecific avian hybrids and somatic cell hybrids.

Chicken fetal-leukemic antigen (CFA) is an oncodevelopmental antigen present on embryonic and neonatal chicken peripheral red blood cells (RBCs) but is not restricted to fetal stages of development in other avian species. Crosses between white Leghorn chickens and Japanese quail resulted in adult hybrids whose peripheral RBCs were positive for CFA. Of the four CFA determinants normally found in adult quail RBCs, only two were present on quail-chicken hybrid RBCs. Adult quail--chicken hybrid RBCs also possessed on CFA determinant associated with early development in both quail and chicken and one chicken-specific CFA determinant. Evidence is presented for the possible association of CFA-positive adult peripheral RBCs and the level of circulating reticulocytes. Crosses between pheasant and turkey (both with CFA-positive adult RBCs) resulted in hybrid adult RBCs expressing only a portion of the parental CFA determinants. Through the formation of somatic cell hybrids between adult chicken and embryonic Japanese quail RBCs, it was possible to induce the appearance of CFA determinants normally restricted to embryonic chicken RBCs. Approximately 50% of the hybrid cells showed reexpression of CFA, and this induction was both time and temperature dependent. Hybridization between RBCs of adult chicken and those of either adult Japanese quail or adult turkey failed to elicit the reexpression of chicken-specific CFA.

Animals↗
PubMed1978

Expression of an onco-developmental antegen among avian species.

Rabbit antisera directed against an onco-developmental antigen on chicken red blood cells have been serologically dissected through specific adsorptions. It is now possible to detect 13 antigenic determinants with the fractionated antisera. The onco-developmental antigen referred to as chicken fetal-leukemic antigen (CFA) is fetal-specific in the white Leghorn chicken, being present on the embryonic but not adult peripheral red blood cells of non-being present on the embryonic but not adult peripheral red blood cells of non-leukemic birds. However, one or more of the onco-developmental antigenic determinants have been detected on adult peripheral red blood cells of non-Gallus avian species, as well as on red blood cells from two adult chicken varieties. For phylogenetic purposes, red blood cells from avian species were characterized for their combinations of CFA determinants. Comparisons among species revealed specific patterns of antigenic expression within phylogenetic groups. Several CFA determinants were restricted in their occurrence to species within a single family, and one determinant was found in all cases where CFA was expressed. The distribution of CFA determinants was used to determine immunological distances among four Galliform species. These distances agreed with the immunological relationships established using different serological markers.

Animals↗