Biomedical subjects

D Guy-Grand

Publications and source records attributed to D Guy-Grand.

At least 73 records · Page 4Linked to original sources

PubMed1980

[Production of a mastocyte growth factor in lymphocyte cultures stimulated by a mitogen or by allogenic cells].

Supernatants from mouse spleen leukocytes stimulated by concanavalin A or from a secondary MLC between donor and recipient of a skin allograft can induce in bone marrow cells an exponential growth of mononuclear cells with cytoplasmic basophilic granules. These cells can be maintained in liquid suspension culture for up to 6 months. They lack the properties of T or b lymphocytes, monocytes or macrophages. They have the morphological features of mast cells or basophils; the cytoplasmic granules are metachromatic for toluidine blue, alcian blue-positive at pH 0.3 and contain histamine. In addition, these cells bind monoclonal mouse IgE. They may be considered as cells of the basophil-mast cell lineage.

Animals↗

PubMed1980

Immune interferon secretion as an expression of immunological memory to transplantation antigens: in vivo generation of long-lived, recirculating memory cells.

Leukocytes from C57Bl/6 mice immunized against DBA/2 strain antigens by intraperitoneal injection of mastocytoma P 815 cells produced, when stimulated in the mixed leukocyte reaction assay with DBA/2 spleen cells, an earlier and more intense secretion of immune interferon than leukocytes from untreated mice. This secondary-type interferon response was independent of cell proliferation. The memory phenomenon was induced by long-lived, recirculating lymphocytes found in spleen, lymph nodes and thoracic duct, but not in the thymus. Memory cells could be recruited into inflammatory sites. They were shown to be specific for H-2 alloantigens, although some cross-reactivity with stimulating cells bearing unrelated H-2 antigens was observed. The possible anti-tumor, antiviral and immunoregulatory roles of this memory phenomenon, and its significance in transplantation immunity are discussed.

Animals↗

PubMed1978

The mouse gut T lymphocyte, a novel type of T cell. Nature, origin, and traffic in mice in normal and graft-versus-host conditions.

Lymphocytes of the mouse intestinal mucosa, identified in tissue sections or purified suspensions of intraepithelial lymphocytes as T cells (gut T lymphocytes [GTL]), were studied in normal mice or in beige mice (the equivalent of the Chediak-Higashi syndrome in man, characterized by giant granules in various cell types, including mast cells). Mice were studied in normal or in germ-free conditions, or during a graft versus host (GVH) reaction resulting from the injection of parental thymocytes into lethally irradiated F1 mice, a condition leading to massive accumulation of T lymphocytes of donor origin in the host gut mucosa. In normal as well as in GVH conditions, a high percentage of the gut IE lymphocytes contain granules (up to 80% in the beige mouse). These granules have ultrastructural, hostochemical and other features resembling those of mast cell granules; in beige mice, up to 50% of them can be shown to contain histamine. Granulated T cells are also found in the lamina propria. It appears that the GTL may progressively lose their surface T antigens when the granules become more developed. Kinetics of [3H]TdR labeling of the GTL, transfer experiments with T cells of various origins, selective [3H]TdR labeling and selective irradiation of the Peyer's patches (PP), and effect of thoraic duct (TD) drainage led to the conclusion that GTL are the progeny of T cells stimulated to divide in the PP microenvironment, which endows them with a gut-homing tendency. From the PP, these cells follow a cycle, migrating to the TD and to the blood to colonize the whole intestinal mucosa, the majority of them as dividing cells undergoing a single round of traffic, with some probably able to recirculate and becoming a more long-lived variety. Antigenic stimulation within the PP is necessary for the emergence of GTL progenitors, but their gut-homing property is unrelated to the antigen as shown with fetal gut grafts, notably in GVH where grafts syngeneic to the host or donor become similarly infiltrated by GTL. On the basis of their properties and of further evidence to be reported elsewhere, it is proposed that GTL belong to a special class of T lymphocytes, related to the immune defenses of the mucosal systems in general, and capable of acting as progenitors of mucosal mast cells.

Animals↗

PubMed1978

A syndrome associating partial albinism and immunodeficiency.

Two unrelated patients with partial albinism, frequent pyogenic infections and acute episodes of fever, neutropenia and thrombocytopenia are described. Their pigmentary dilution was characterized by large clumps of pigments in the hair shafts and an accumulation of melanosomes in melanocytes. Melanocytes had few short dendritic expansions, and keratinocytes were hypopigmented. No or few Langerhans' cells were detected in skin by electron microscopy and ATP-ase reactions. This pigmentary dilution, different from all other human albinisms, resembles the unique defect of the mutant dilute (d-d) mouse. Despite the presence of an adequate number of T and B lymphocytes, the patients were hypogammaglobulinemic, deficient in antibody production and incapable of manifesting delayed skin hypersensitivity or of rejecting skin grafts. Their leukocytes did not stimulate normal lymphocytes and could not generate cytotoxic cells during mixed leukocyte reaction. T lymphocytes of one patient were unable to exert a helper effect on the maturation of B lymphocytes into immunoglobulin-containing cells following in vitro stimulation with pokeweed mitogen. This suggests that the humoral deficiency might be secondary to a defect of helper T lymphocytes. Granulocytes did not show any morphologic abnormality, and their bactericidal activity was only moderately reduced. An increased number of polymorphonuclear leukocytes with polar distribution of Concanavaline A (Con A) receptors (capping) was found in one patient and her parents. The family histories suggest that this syndrome is transmitted as an autosomal recessive character.

Albinism↗

PubMed1978

Increase in the population of duodenal immunoglobulin A plasmocytes in axenic mice associated with different living or dead bacterial strains of intestinal origin.

Various bacterial strains were tested for their ability to stimulate immunoglobulin A (IgA) plasmocytes to populate the duodenal lamina propria in axenic mice. The mice were associated with the strains for at least 4 weeks. The strains inhabiting the conventional mouse intestine and belonging to the genera Lactobacillus, Streptococcus, Eubacterium, Actinobacillus, Micrococcus, Corynebacterium, and Clostridium (including the extremely oxygen-sensitive ones) are only slightly or nonimmunogenic, whereas the strains belonging to the genera Bacteroides and Escherichia have an immunogenic effect. The same result was obtained with Bacteroides and Escherichia strains isolated from the digestive tract of other animal species. The kinetics of appearance of intestinal IgA plasmocytes are similar in axenic mice monoassociated with a stimulatory strain and in conventional mice. The association of two or more strains with axenic mice leads either to the same or a greater number of duodenal IgA plasmocytes as that obtained with the most stimulatory strain monoassociated with axenic mice. The maximum stimulation recorded in all of these trials represents about two-thirds of that observed in conventional mice and was obtained in the duodenum of gnotoxenic mice harboring four bacterial strains isolated from the conventional mouse microflora. The orally administered killed cells of two immunogenic strains, E. coli and Bacteroides sp., are as immunogenic as the living cells, provided that their concentration in the digestive tract is sufficient.

Actinobacillus↗

PubMed1975

Peyer's patches, gut IgA plasma cells and thymic function: study in nude mice bearing thymic grafts.

Nude mice have poorly developed Peyer's patches with very small or no germinal centers and little lymphoid cell proliferation, and a marked decrease in the number of gut-IgA plasma cells. Thymus grafts, which restore the T lymphocyte population of their lymphoid organs to nearly normal levels, lead to a considerable development of the Peyer's patches and of their germinal centers, assocaited with a considerable increase in gut IgA plasma cells, and in the serum IgA level. These findings are consistent with the postulated relationship between the Peyer's patches germinal center cells and the gut IgA plasma cells, and might help to explain the association of thymic defects, low serum IgA, and lack of intestinal IgA plasma cells observed in some immunodeficiency syndromes of man. Nude mice also have marked decrease in the number of lymphocytes present within the intestinal epithelium. These intraepithelial lymphocytes lymphocytes, which have been shown to be of T nature, are restored to normal numbers after thymus grafting.

Animals↗

PubMed1974