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Biomedical subjects

U Lösch

Publications and source records attributed to U Lösch.

At least 55 records · Page 3Linked to original sources
PubMed1989

Granulocyte isolation from whole blood of goat, sheep, cattle, horse, dog, pig, and man.

A simple two step procedure for the isolation of caprine, ovine, bovine, equine, canine, porcine and human peripheral blood granulocytes is described. After enrichment of granulocytes by centrifugation, contaminating erythrocytes are lysed hypotonically. Recovery, purity, and viability of the granulocyte suspensions are determined. FACScan analysis of the cell suspensions measuring cellular size by forward and sideward light scatter is compared with the corresponding analysis of whole blood leukocytes. Constituencies of the isolated cell suspensions and loss of granulocyte subpopulations through isolation procedure is discussed with regard to granulocyte function assays.

Animals↗
PubMed1989

Chicken egg antibodies for prophylaxis and therapy of infectious intestinal diseases. II. In vitro studies on gastric and enteric digestion of egg yolk antibodies specific against pathogenic Escherichia coli strains.

Specific antibodies directed against enterotoxic E. coli strains from the yolk of immunized hens were exposed in vitro to the influence of varying digestive phenomena like reduction of pH and proteolytic digestion. The remaining antibody activity was tested in a specific ELISA system. It could be shown that already within the stomach a considerable loss in antibody activity caused by a lowering of pH and peptic cleavage can be expected. A further loss in antibody activity is due to the proteolytic effect of the pancreas proteases trypsin and chymotrypsin. It was found that antibodies in protein rich solutions like egg or yolk suspensions were more resistant than mere globulin fractions or antibodies isolated by affinity chromatography. Prospects for further in vivo tests are discussed.

Animals↗
PubMed1989

Production of antibodies to canine distemper virus in chicken eggs for immunohistochemistry.

The present study describes the application of egg yolk antibodies in immunohistochemistry. In order to obtain specific antibodies against canine distemper virus (CDV), chickens were immunized with attenuated virus. Distinct antibody titres in serum and yolk could be detected by means of a modified plaque/focus immunoassay (ELISA) two weeks after a second immunization. The lower concentrations in corresponding yolk globulin preparations are attributed to the loss of antibodies caused by the isolation procedure (dextran and ammonium sulfate precipitation). After verification of the antibody specificity by indirect immunofluorescence technique high titred globulin fractions were employed in immunohistochemistry using the Avidin-Biotin-Complex method. A specific and distinct immunostaining in formalin fixed and paraffin embedded brain sections of CDV-infected dogs was obtained. The advantages of egg yolk antibodies for immunological purposes are discussed in detail.

Animals↗
PubMed1989

[Modification of avian humoral immunoreactions by Influex and Echinacea angustifolia extract].

Medicinal complex drugs as well as single ethanolic or aqueous extracts of several plants are commonly used to increase the natural resistance to various infections, though their efficacy and mechanism of action are not yet well elucidated. In the present study, we investigated two problems: firstly, whether the complex drug (Influex) and Echinacea angustifolia extract do stimulate the immunoglobulin and antibody synthesis in chickens immunized with human serum albumin; and secondly, whether a restoration of IgG-synthesis in immunodefective (dysgammaglobulinemic) UM-B 19 chickens is possible with these plant preparations, i.e. if the BG cells which may possibly be present can be polyclonally or antigen specifically stimulated. The preparations were administered orally in two doses, after which the complete immunoglobulin concentration was determined by rocket immunoelectrophoresis and the antibody production by ELISA. The effect of ethanolic solvent was taken into account. The administration of the complex drug to normal Leghorn chickens induced a rise in the serum immunoglobulin concentration, as well as an increase in the three classes of antibody. By the immunodeficient chickens (IgG concentration was below the level of test sensitivity at the start), the administration of the drug led to a slight production in IgG and antibody.

Animals↗
PubMed1988

Avian T cells expressing gamma delta receptors localize in the splenic sinusoids and the intestinal epithelium.

A panel of murine mAb specific for the chicken homologues of the CD3, CD4, CD8, TCR gamma delta, and TCR alpha beta has been used to study the distribution of T cells expressing these markers in sections of chicken lymphoid tissues. These studies have revealed that the T cells possessing the two classes of TCR occupy distinct histologic microenvironments. The TCR1+ cells (gamma delta TCR homologue) are localized preferentially in the splenic sinusoids and the intestinal epithelium, where most of them express the CD8 homologue. The TCR2+ cells (alpha beta TCR homologue), a majority of which express the CD4 homologue, are found primarily in the splenic periarteriolar sheath and the lamina propria of the intestine. The frequency and distribution of the two classes of T cells in the thymus is also unique. The different tissue homing patterns of the TCR1 and TCR2 cells suggest that they represent separate lineages of T cells with distinctive physiologic roles.

Animals↗
PubMed1988

Characterization and functional properties of a novel monoclonal antibody which identifies a T cell receptor in chickens.

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.

Animals↗
PubMed1988

Differential expression of two T cell receptors, TcR1 and TcR2, on chicken lymphocytes.

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.

Animals↗
PubMed1987

A chicken leukocyte common antigen: biochemical characterization and ontogenetic study.

A monoclonal antibody, designated CL-1, was produced by immunizing mice with chicken peripheral blood lymphocytes (PBL) and selected in an indirect immunofluorescence assay. CL-1 characterizes a cell surface antigen expressed on all chicken hemopoietic cells except mature erythrocytes. Cells stained by CL-1 were detected at early stages of embryonic development in the various hemopoietic compartments. CL-1 reacts with two chicken PBL proteins of 200 kDa and 215 kDa which are probably the homologues of the T-200 and B-220 antigens previously described in the mouse. Moreover, CL-1 does not react with quail hemopoietic tissues and can be useful in experiments using quail-chick chimeras to study the ontogeny of the hemopoietic system.

Aging↗
PubMed1987

Attempts to localize the defect in dysgammaglobulinemia of UM-B19 chickens by studying the effect of immunomodulating substances on immunoglobulin and antibody production.

The extreme decreased levels of IgG in dysgammaglobulinemic UM-B19 chickens are linked with decreased antibody activity. Antibody activity to T-dependent (although diminished) and T-independent antigens is present but is restricted to IgM and IgA antibodies. Complete Freund's adjuvant enhances the existing isotype pattern of serum immunoglobulins and antibodies. The antibody response to a "T-independent" antigen (B. abortus) is greatly increased by CFA in dysgammaglobulinemic chickens. Beside the appearance of high levels of IgG in dysgammaglobulinemic chickens during the first weeks of life and in transitory dysgammaglobulinemia, remarkable IgG synthesis can be temporarily induced by the mitogenic activity of LPS and even more by the regulatory function of Levamisole. Furthermore, LPS and Levamisole induce IgG antibody synthesis to concomitantly administered antigen, the IgG antibodies appearing within the normal time. Contrary to a missing feedback inhibition from total IgG to IgM serum immunoglobulins, a feedback inhibition from IgG to IgM antibodies is found. No correlation can be found between Levamisole-induced IgG immunoglobulin concentrations, and IgG antibodies. Germfree rearing for one week or longer prevents the dysgammaglobulinemic defect. The following conclusions are drawn: Early antigenic stimulation seems to be the inducing factor for dysgammaglobulinemia in UM-B19 chickens. A BG cell pool is still present in adult dysgammaglobulinemic chickens. This BG cell pool is probably diminished to a varying extent. T cell helper functions seem to be present (albeit they may be disturbed) and can be stimulated. IgG specific T cell suppression is probable. From these conclusions the etiology of the dysgammaglobulinemia in UM-B19 chickens is hypothesized to be primarily due to delayed bursal development: Immature BG cells are eliminated by environmental antigens during the neonatal period in a process similar to tolerance induction. This event, in turn, induces suppressor mechanism(s) or disturbance in helper mechanism(s).

Adjuvants, Immunologic↗
PubMed1986

Immunological identification of avian monomeric and polymeric immunoglobulin M and immunoglobulin A after fractionation on sodium dodecylsulfate pore gradient polyacrylamide gels.

Naturally existing variants of Immunoglobulin M (IgM) and Immunoglobulin A (IgA) in the serum of immunologically competent, as well as immunologically defective UM-B19 chickens can be detected without time consuming purification. The different molecular forms of IgM and IgA were separated by gel filtration. Pentameric IgM and dimeric IgA were well separated from the 7S-peak that contained monomeric IgM and IgA. A method for immunological identification of the protein components is described. Pore gradient gel electrophoresis was combined with antigen-antibody crossed electrophoresis in horizontal agarose slabs. The principle of the method is that IgM and IgA in their different molecular forms in the mixtures to be assayed after gel filtration are first separated with high resolution by sodium dodecylsulfate (SDS) polyacrylamide gel electrophoresis using a pore gradient of 3 to 15%. In the second step, a slab of polyacrylamide gel with the separated proteins in transferred onto agarose layers containing appropriate anti- mu- and anti-alpha antiserum and SDS in a concentration of .01%. The technique is easy to perform and gives reproducible results. In chicken serum, the monomeric state of IgM (184,000 d), along with the pentameric state (920,000 d) were identified. Serum IgA exists in dimeric (340,000 d) and in monomeric (170,000 d) states. No differences between the commercial Leghorn and dysgammaglobulinemic and normogammaglobulinemic lines were found.

Agammaglobulinemia↗
PubMed1983

Distribution of IgM-, IgG-, and IgA-positive cells in lymphatic organs of normo- and dysgammaglobulinemic UM-B19 chickens.

Lymphatic organs of normo- and dysgammaglobulinemic chickens were studied by immunohistochemical methods concerning IgM-, IgG-, and IgA-positive cells. IgM- and IgA-positive lymphocytes and plasmacytic cells are similarly distributed in dys- and normogammaglobulinemic chickens. Follicles of the bursa of Fabricius contain cortical lymphocytes weakly and medullar lymphocytes distinctly stained by anti-IgM, as well as some larger irregularly shaped cells with intensely labeled cytoplasm. In spleen, periellipsoid lymphocytes, some red pulp lymphocytes, and varying numbers of plasmacytic cells are also distinctly labeled by anti-IgM. IgA-positive lymphocytes are not present in the bursa of Fabricius, but the bursal medulla is populated by some irregular, mostly longish cells with cytoplasmic IgA reaction. Spleen contains a few IgA-labeled lymphocytes and plasmacytic cells. The only difference between normo- and dysgammaglobulinemic chickens is found in IgG-positive cells, which are absent in permanently dysgammaglobulinemic chickens. The results from dysgammaglobulinemic chickens show that IgA can also be produced in untreated chickens lacking IgG synthesis and suggest that the theory of an IgM leads to IgG leads to IgA sequence is unlikely.

Agammaglobulinemia↗