Biomaterial Database

Generalized toxicity of L-leucyl-leucine-methyl ester for lymphocyte functions. 1990

A M Mowat, and P A Leck

Department of Bacteriology and Immunology, Western Infirmary, Glasgow, U.K.

This study investigated the hypothesis that sensitivity to L-leucyl-leucine-methyl ester (Leu-leu-O-Me) can be used to identify a role for cytotoxic lymphocytes in alloreactivity. Treatment of donor lymphocytes with Leu-leu-O-Me profoundly inhibited their ability to induce three separate models of murine graft-versus-host reaction (GVHR). This was observed for all aspects of GVHR examined, including weight loss, splenomegaly and activation of natural killer (NK) cells. These effects were not influenced by whether specific cytotoxic T lymphocytes (CTL) were involved in individual models of GVHR. Leu-leu-O-Me not only eliminated NK and CTL activity in vitro, but had identical effects on the proliferation of T and B lymphocytes in response to a variety of mitogenic stimuli. Finally, Leu-leu-O-Me prevented immune lymphocytes from mediating both class I and class II major histocompatibility complex (MHC)-restricted delayed-type hypersensitivity (DTH) responses in vivo. It is concluded that Leu-leu-O-Me has non-specific toxicity for most lymphocyte function and that it cannot be used as a specific means of predicting the functional roles of CTL.

UI	MeSH Term	Description	Entries
D006968	Hypersensitivity, Delayed	An increased reactivity to specific antigens mediated not by antibodies but by sensitized T CELLS.	Hypersensitivity, Tuberculin-Type,Hypersensitivity, Type IV,Tuberculin-Type Hypersensitivity,Type IV Hypersensitivity,Delayed Hypersensitivity,Delayed Hypersensitivities,Hypersensitivity, Tuberculin Type,Tuberculin Type Hypersensitivity,Tuberculin-Type Hypersensitivities,Type IV Hypersensitivities
D007166	Immunosuppressive Agents	Agents that suppress immune function by one of several mechanisms of action. Classical cytotoxic immunosuppressants act by inhibiting DNA synthesis. Others may act through activation of T-CELLS or by inhibiting the activation of HELPER CELLS. While immunosuppression has been brought about in the past primarily to prevent rejection of transplanted organs, new applications involving mediation of the effects of INTERLEUKINS and other CYTOKINES are emerging.	Immunosuppressant,Immunosuppressive Agent,Immunosuppressants,Agent, Immunosuppressive,Agents, Immunosuppressive
D007694	Killer Cells, Natural	Bone marrow-derived lymphocytes that possess cytotoxic properties, classically directed against transformed and virus-infected cells. Unlike T CELLS; and B CELLS; NK CELLS are not antigen specific. The cytotoxicity of natural killer cells is determined by the collective signaling of an array of inhibitory and stimulatory CELL SURFACE RECEPTORS. A subset of T-LYMPHOCYTES referred to as NATURAL KILLER T CELLS shares some of the properties of this cell type.	NK Cells,Natural Killer Cells,Cell, NK,Cell, Natural Killer,Cells, NK,Cells, Natural Killer,Killer Cell, Natural,NK Cell,Natural Killer Cell
D008214	Lymphocytes	White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.	Lymphoid Cells,Cell, Lymphoid,Cells, Lymphoid,Lymphocyte,Lymphoid Cell
D008815	Mice, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.	Inbred Mouse Strains,Inbred Strain of Mice,Inbred Strain of Mouse,Inbred Strains of Mice,Mouse, Inbred Strain,Inbred Mouse Strain,Mouse Inbred Strain,Mouse Inbred Strains,Mouse Strain, Inbred,Mouse Strains, Inbred,Strain, Inbred Mouse,Strains, Inbred Mouse
D003602	Cytotoxicity, Immunologic	The phenomenon of target cell destruction by immunologically active effector cells. It may be brought about directly by sensitized T-lymphocytes or by lymphoid or myeloid "killer" cells, or it may be mediated by cytotoxic antibody, cytotoxic factor released by lymphoid cells, or complement.	Tumoricidal Activity, Immunologic,Immunologic Cytotoxicity,Immunologic Tumoricidal Activities,Immunologic Tumoricidal Activity,Tumoricidal Activities, Immunologic
D004151	Dipeptides	Peptides composed of two amino acid units.	Dipeptide
D006087	Graft vs Host Reaction	An immunological attack mounted by a graft against the host because of HISTOINCOMPATIBILITY when immunologically competent cells are transplanted to an immunologically incompetent host; the resulting clinical picture is that of GRAFT VS HOST DISEASE.	HLA Sensitization,Human Leukocyte Antigen Sensitization,Sensitization, HLA
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013602	T-Lymphocytes, Cytotoxic	Immunized T-lymphocytes which can directly destroy appropriate target cells. These cytotoxic lymphocytes may be generated in vitro in mixed lymphocyte cultures (MLC), in vivo during a graft-versus-host (GVH) reaction, or after immunization with an allograft, tumor cell or virally transformed or chemically modified target cell. The lytic phenomenon is sometimes referred to as cell-mediated lympholysis (CML). These CD8-positive cells are distinct from NATURAL KILLER CELLS and NATURAL KILLER T-CELLS. There are two effector phenotypes: TC1 and TC2.	Cell-Mediated Lympholytic Cells,Cytotoxic T Cells,Cytotoxic T Lymphocyte,Cytotoxic T-Lymphocytes,TC1 Cell,TC1 Cells,TC2 Cell,TC2 Cells,Cell Mediated Lympholytic Cells,Cell, Cell-Mediated Lympholytic,Cell, TC1,Cell, TC2,Cell-Mediated Lympholytic Cell,Cytotoxic T Cell,Cytotoxic T Lymphocytes,Cytotoxic T-Lymphocyte,Lymphocyte, Cytotoxic T,Lympholytic Cell, Cell-Mediated,Lympholytic Cells, Cell-Mediated,T Cell, Cytotoxic,T Lymphocyte, Cytotoxic,T Lymphocytes, Cytotoxic,T-Lymphocyte, Cytotoxic