A monoclonal antibody, TcR2, has been shown to recognize an avian homologue of the mammalian alpha/beta T cell receptor (TcR). The TcR2-reactive molecule was found to be a T3-associated heterodimer with relative molecular mass of 90-kDa consisting of disulfide-linked 50-kDa and 40-kDa polypeptides. The sizes of the deglycosylated TcR2 polypeptides differed from those of TcR1, an avian homologue of the mammalian gamma/delta T cell receptor. Immunofluorescence analysis revealed that TcR1 and TcR2 are expressed on separate populations of T cells during their development first in the thymus and then in the periphery. Ontogenetic studies revealed that the TcR1+ thymocytes are generated first and the generation of TcR2+ cells begins approximately 3 days later. While most TcR2+ cells in the thymus expressed both CT4 and CT8, TcR2+ cells in blood and the spleen were either CT4+ or CT8+. The TcR1+ cells in blood and thymus were CT4-CT8-, but the majority of TcR1+ cells in the spleen surprisingly expressed the CT8 marker. The data suggest that TcR1 and TcR2 cells are generated in the thymus as separate T cell sublineages.
The avian embryo and its accessibility in the egg offer significant advantages for the analysis of immune system development. The separate developmental pathways ofthymus-dependent T cells and bursa-dependent B cells (1-4) and their derivation from hemopoietic stem cells (SC)' (5-7) were first disclosed in studies of chick development. Chick-quail chimeras were used to show that blood-borne stem cells periodically migrate into the thymus in response to chemoattractants produced by thymic epithelial cells (8, 9). The first wave of stem cell influx into the thymus begins on the fifth day of embryonic development (E5) in the quail and on E6.5 in the chick, and this influx persists for 1-2 d. At least two additional waves of stem cells enter the embryonic thymus after nonreceptive intervals of ti4 d (9, 10).The development of mAbs with specificity for the chicken TCRs and associated cell surface molecules (CD3, CD4, CD8) has allowed detailed study of the T cell progeny of hemopoietic stem cells (11-18). Sequential development of three sublines of daughter T cells has been defined using these antibodies. The first consists of T cells expressing the avian TCR-y/b homologue in association with the avian CD3 protein complex (13). These TCR1/CD3-bearing cells appear first in the E12 thymus .T cells expressing the avian a/a receptor complex, TCR2/CD3, appear on E15 (14-16).As in mammals, the immature TCR2 cells express both CD4 and CD8 molecules, whereas the TCR1 thymocytes express neither. A third T cell sublineage has recently been identified as cells expressing a different receptor complex (17, 18). These TCR3/CD3+ cells begin to appear in the thymus on E18.The present experiments, using chick-quail chimeras constructed by embryonic thymus engraftment, were primarily designed to examine lineage relationships among the different waves of stem cells and their intrathymic progeny. Specifically, we sought
Summary Antibody titers achieved by the immunization of hens are presented with examples. The transfer of immunoglobulins from the blood or oviduct to the egg and the distribution of these proteins in the various compartments which develop in the egg during incubation are quantitatively recorded. Possible procedures for extracting IgG antibody from the yolk are pointed out. Results concerning acid and temperature resistance of yolk antibodies are presented. An overview of the literature concerning with diagnostic use of yolk antibodies is given. The possible therapeutic application of egg antibodies is discussed. Zusammenfassung Das Hühnerei als Antikörperquelle Die durch die Immunisierung von Hühnern erzielten Antikörpertiter werden beispielhaft dargestellt. Der Transfer der Immunglobuline aus der Blutbahn bzw. dem Legeapparat in das Ei und die nachfolgende Umverteilung dieser Proteine in die sich während der Inkubation bildenden Eikompartimente werden quantitativ erfaßt. Die Möglichkeiten der IgG‐Antikörper‐Extraktion aus dem Dotter werden aufgezeigt. Ergebnisse zur Säure‐ und Temperatur‐Resistenz der Dotterantikörper werden vorgelegt. Eine Literaturübersicht bezüglich des Einsatzes von Dotterantikörpern wird gegeben. Der mögliche therapeutische Einsatz von Ei‐Antikörpern wird erörtert.
A monoclonal antibody, mAb6, was produced that specifically bound to chicken T lymphocytes. Immunofluorescence analysis using a fluorescence-activated cell sorter revealed that the antibody reacted with approximately 50% of blood lymphocytes and with approximately 40% of splenocytes and thymocytes. It did not react with bursal cells and erythrocytes. Among different types of hemopoietic cell lines, only a T cell line was reactive with mAb6. When coupled to Sepharose 4B beads, mAb6 was found to be highly mitogenic for chicken T cells. In soluble form, mAb6 inhibited concanavalin A-induced T cell proliferation and the cytotoxic activity of allosensitized T cells, the inhibition occurring in a dose-dependent manner for both assays. Thus, the tissue distribution and the effects of this antibody on T cell responses suggest that mAb6 recognizes a T cell receptor present on a large proportion of chicken T cells.
While afi T cells in mammals may express one of many variable (V) gene families in the 13 had greater than normal numbers of Vp2' T cells and appeared as healthy as thymectomized and untreated controls. While production of IgM and IgG antibodies was unimpaired, IgA antibody production was severely compromised in the Vpldepleted birds. The levels of secretory IgA in bile and lung lavage fluid were reduced 1000-to 10,000-fold and secretory IgA antibodies were not produced in response to mucosal immunization. B-cell production of IgA antibodies thus appears to require T cells expressing the Vp1 genes, whereas T cells that express the Vp2 genes lack this capacity.Most of the T cells in mammals express an antigen receptor composed of a and , f chains, while the others express a T-cell receptor (TCR) composed of 'y and 8 subunits (1). Avian homologues of the mammalian a/3 and y5 TCRs can be identified with monoclonal antibodies. The chicken ySTCR is identified with the TCR1 antibody (2) and two types of af3TCR are identified in gallinaceous birds with the TCR2 and TCR3 antibodies (3)(4)(5). The key to this unexpected finding is provided by the recent cloning of genes in the chicken TCR X3 locus. This P locus contains two variable (V) gene families, one diversity (D) gene, four joining (J) genes, and a single constant region (C) gene (6). Chicken a3 T cells therefore may express either V91 or V,2 genes, the products of which can be recognized, respectively, by the TCR2 and TCR3 antibodies (7). While there is little sequence homology (30%) between the Vp1 and Vp2 genes, members within the two families are very similar (>95% homology). Thus, to an even greater extent than in mammals, which have many Va gene families (1), TCR(3 diversity in birds is generated primarily by junctional variations created by V-D-Jp splicing and insertion of nonencoded nucleotides (6). Interestingly, the numerous Va genes in mammals can be assigned to two superfamilies on the basis of invariant sequences (8): V91 superfamily gene members encode an arginine at position 64 and aspartic acid at position 86 to form a salt bridge between these residues, while V,2 genes instead feature an invariant codon for tyrosine at position 65. These features are retained in the chicken V91 and Vp2 genes, respectively (6).The chicken therefore provides a relatively simple model for study of the functional roles of acB T cells by using the two prototype Va genes. In earlier studies, we found that development ofthe TCR2 thymocyte population can be selectively inhibited by embryonic administration of the TCR2 (V,81 specific) monoclonal antibody (9, 10). When this antibody treatment is combined with surgical removal of the thymus after hatching, sustained suppression of the TCR2 cell population can be achieved in young birds. In the present study, we confirmed the selective suppression of TCR2' cells and observed a profound effect of this treatment on the integrity of mucosal immunity. MATERIALS AND METHODSChickens. Chickens hatched from fertile outbred Wh...
Avian homologues of mammalian y8 and a13T-cell antigen receptors, TCR1 and TCR2, have been identified with monoclonal antibodies. These TCR isotypes are associated with the avian CD3 proteins on the T-cell surface. During chick development, T-cell subpopulations bearing CD3/TCR1 or CD3/TCR2 receptor complexes are generated sequentially in the thymus and seeded to the periphery in the same order. In this study, we used two-color immunofluorescence to identify the subsequent development of a third subpopulation of T cells, provisionally named TCR3. These CD3' cells, which expressed neither TCR1 nor TCR2, were first detected in the blood 1 week after hatching and increased numerically as a function of age to account for s15% ofthe circulating T-cell pool in adults. Most (>80%) of the TCR3 cells expressed the CD4 accessory molecule. The relative incidence of the TCR3 subpopulation increased dramatically as a consequence of embryonic treatment with anti-TCR2 antibody and thymectomy after hatching. Two disulfide-linked polypeptides, of Mr 48,000 and 40,000, were associated with the CD3 complex on the TCR3 cells. Examination of the TCR protein backbones and peptide mapping of the TCR chains after partial proteolysis indicated that the TCR3 heterodimer differs from both TCR1 and TCR2. These results suggest the existence of a third class of T-cell receptors in birds.Most mammalian T cells express an antigen-specific T-cell receptor (TCR) composed ofa and ,8 subunits (1-6). A limited number of T cells express a second TCR isotype composed of y and 8 chains in association with the invariant CD3 complex (7-13). Avian homologues of the mammalian vy and af3 TCRs, TCR1 and TCR2, have recently been identified in the chicken through the use of mouse monoclonal antibodies that are specific for nonpolymorphic determinants of these isotypes (14-18). Although the TCR1 and TCR2 subpopulations show remarkable conservation, the TCR1 subpopulation is significantly larger in birds than in mammals (15) (23) from outbred or FP strain chickens. Lymphocyte subpopulations were isolated by an indirect "panning" procedure (24) followed by fluorescence-activated cell sorting. In these experiments, lymphoid cells from the circulation were labeled with monoclonal antibodies against TCR1, TCR2, and Ia antigens. Cells containing these antigens were removed by panning on plates coated with goat anti-mouse immunoglobulins. The nonadherent, negatively selected subpopulation of cells was further purified by staining with FITC-conjugated goat anti-mouse immunoglobulins and sorted by automated flow cytometry with a FACS IV instrument (Becton Dickinson Immunocytometer Systems). Direct immunofluorescence staining was carried out by incubation of 106 cells with phycoerythrin-conjugated monoclonal antibodies. For indirect immunofluorescence, the cells were incubated with monoclonal antibodies followed by FITC-conjugated goat anti-mouse immunoglobulins. Relative immunofluorescence intensities were measured by automated flow cytometry using a FACScan in...
SUMMARYPigeon immunoglobulin classes IgG and IgA were purified and specific isotype antisera were produced in rabbits. The antisera were used to develop a quantitative assay for both immunoglobulins.Serum IgG concentrations in relation to age showed a similar pattern in pigeons to that in chickens. The same applies to the transfer of maternal immunoglobulins via egg. Besides this transfer mechanism, an additional transfer of immunoglobulins exists in the pigeon via feeding of crop milk. Crop milk contains considerable amounts of IgA (1.45 mg/ml) and significantly less IgG (0.34 mg/ml). During day 1 intestinal absorption of IgA is possible to a very low extent. Most of the IgA, as well as IgG, remains in the intestine to provide local immunity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.