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M A Cuchens

Publications and source records attributed to M A Cuchens.

43 records · Page 3Linked to original sources
PubMed1978

The effects of anti-IgD on serum immunoglobulins, antibody production, and immunoglobulin-bearing cells in adult rats.

Rabbit anti-rat IgC (delta-specific) injected subcutaneously into adult rats resulted in hypergammaglobulinemia, increased serum immunoglobulins, increased antibody production, and alterations in the percentages of PBL expressing IgD and IgM. Serum IgM, IgG2a and IgG2c concentrations were increased 100%, 125%, and 200%, respectively, over controls, whereas IgA levels were not altered. Increases in the serum immunoglobulins were predominately due to an increase in antibodies to the rabbit serum components. A depletion of IgD-IgM bearing lymphocytes in the peripheral blood was observed after 24 hr of injection. Percentages of IgC-IgM bearing lymphocytes returned to normal by day 4 and were significantly increased (approximately 2-fold) by day 8. The in vivo effects of anti-delta in rats were similar to those reported in the monkey. Possible modes of action of the anti-delta and the significance of these results in relation to the biologic function of membrane IgD are discussed.

Animals↗
PubMed1977

Phylogeny of lymphocyte heterogeneity. I. Membrane immunoglobulins of teleost lymphocytes.

Immunofluorescence studies of bream lymphoid tissues revealed that our 90% of the lymphocytes from blood, anterior kidney, spleen and thymus exhibited membrane immunoglobulin determinants. Furthermore, a majority of such cells were observed to undergo patching and capping when the membrane proteins were complexed with antisera to fish serum immunoglobulins. Lactoperoxidase catalysed radioiodination, detergent lysis and immunoprecipitation with appropriate antisera were employed to study the properties of this membrane immunoglobulin. Quantification, by inhibition of immunoprecipitation with serum immunoglobulin, indicated the average amount of immunoglobulin determinants for bream lymphocytes from either blood, anterior kidney, spleen or thymus to be about half that present on mouse B cells. Physiochemical characterization of labeled membrane immunoglobulin from bream lymphocytes suggested that only one class of immunoglobulin heavy chain was present and that about one-half of this material resembled the monomeric (2H-2L chain) IgM-like proteins present in bream serum. A major unanswered question raised by this study was whether or not certain of the bream membrane immunoglobulin determinants were associated with molecules that did not resemble "classical" immunoglobulins.

Animals↗
PubMedDate not supplied

Activation of channel catfish B cells by membrane immunoglobulin cross-linking.

This study demonstrates for the first time that teleost, specifically channel catfish, B cells proliferate in response to membrane immunoglobulin (mIgM) cross-linking. An early activation event mediated by anti-IgM ligation involved a rapid increase in intracellular calcium levels similar to the situation seen in mammalian B cells. In addition, catfish B cells, like mammalian B cells, did not exhibit such calcium changes following stimulation with lipopolysaccharide. Another consequence of catfish B cell mIgM cross linking was the rapid induction of intracellular protein phosphorylation. A number of proteins were phosphorylated on tyrosine residues within minutes after anti-Ig stimulation, indicating the activation of protein tyrosine kinases similar to the situation observed in mammalian B cells. These early intracellular activation events suggest that fish B cells, like mammalian B cells, employ a conserved signal transduction system upon mIgM ligation. This ability to transduce activation signals, coupled with the fact that catfish mIgM have a very short cytoplasmic tail, implies that catfish mIgM is probably associated with accessory molecules required for signal transduction. In this regard, several of the tyrosine phosphorylated catfish proteins exhibited relative molecular weights similar to the mammalian Ig-alpha and Ig-beta/gamma accessory molecules, and may represent candidates for the putative catfish mIgM accessory molecules.

Animals↗
PubMedDate not supplied

Effects of oleic acid on murine CD4+ T cell death and anti-CD3 or superantigen induced proliferation at low temperature.

Studies were conducted to examine the effects of low, yet physiologically relevant, temperatures on murine T lymphocyte responses. Akin to ectothermic vertebrate responses, lectin-induced murine T cell proliferation was previously shown to be ablated at temperatures 10 degrees C below optimal (i.e. 27 degrees C); responsiveness at 27 degrees C was restored by the addition of oleic acid (18:1). The aim of the present study was to address the mechanism involved in such low temperature suppression. Murine splenic CD4+ T lymphocytes stimulated with either alpha CD3 or SEB exhibited cell death, as opposed to anergy, at 27 degrees C. However proliferation was observed in the presence of 18:1. Thus low temperature-suppression of murine CD4+ T cells is also mediated through TCR and/or CD3 pathways. Additional studies examining the temporal effects of adding 18:1, as well as temperature shifts, indicated that the cell death induced by stimulation at low temperature was preventable by 18:1.

Animals↗
PubMedDate not supplied

Identification of Mycoplasma gallisepticum and M. synoviae by flow cytometry.

Immunofluorescence and flow cytometric methods were examined to detect and distinguish Mycoplasma gallisepticum and M. synoviae. The procedure employed 24-hr broth cultures of each organism, direct immunofluorescence staining with either homologous or heterologous antiserum, and analyses by flow cytometry. The organisms were distinguishable on the basis of fluorescent profiles when stained with the appropriate antiserum.

Cells, Cultured↗