Biomaterial Database

Cloned human CD4+ cytotoxic T lymphocytes specific for Toxoplasma gondii lyse tachyzoite-infected target cells. 1993

T J Curiel, and E C Krug, and M B Purner, and P Poignard, and R L Berens

Infectious Disease Division, University of Colorado Health Sciences Center, Denver 80262.

Infection with Toxoplasma gondii is an important cause of morbidity and mortality throughout the world. In immunocompetent hosts, the infection is usually not significant. However, infection occurring in neonates or other individuals with defective cellular immunity (such as recipients of organ allografts or persons with AIDS) may be life threatening. An effective vaccine to prevent toxoplasmosis, or immunotherapy for persons already infected with Tg would be important additions to the therapeutic armamentarium. We cloned toxoplasma-specific CTL from the PBMC of an asymptomatic individual with serologic evidence for prior Tg infection by stimulation with Ag produced from the RH strain of Tg. These CTL were exclusively of the CD3+, CD4+, CD8- surface phenotype, and lysed autologous target cells that had been either pulsed with Toxoplasma Ag, or infected with live tachyzoites. Lysis of target cells was inhibited by incubation of CTL with anti-T cell antibody, or by incubation of target cells with anti-DR antibody or chloroquine. These CTL also lysed target cells either pulsed with Ag derived from C strain Tg or infected with live C strain tachyzoites, indicating cross-reactivity of recognition. Unlike recently reported murine or human CD8+ Tg-specific CTL, which lysed tachyzoites in an extracellular, and hence HLA-unrestricted environment, these CD4+ CTL had no effect on the infectivity of extracellular tachyzoites. CD8+ Tg-specific CTL were not derived from this donor despite several different approaches to their generation. These data confirm previous reports of human Tg-specific CTL, and extend these observations to include CD4+ CTL. These findings suggest that specific immunotherapy directed against Tg, as well as the development of a preventive vaccine, may be possible.

UI	MeSH Term	Description	Entries
D007111	Immunity, Cellular	Manifestations of the immune response which are mediated by antigen-sensitized T-lymphocytes via lymphokines or direct cytotoxicity. This takes place in the absence of circulating antibody or where antibody plays a subordinate role.	Cell-Mediated Immunity,Cellular Immune Response,Cell Mediated Immunity,Cell-Mediated Immunities,Cellular Immune Responses,Cellular Immunities,Cellular Immunity,Immune Response, Cellular,Immune Responses, Cellular,Immunities, Cell-Mediated,Immunities, Cellular,Immunity, Cell-Mediated,Response, Cellular Immune
D002999	Clone Cells	A group of genetically identical cells all descended from a single common ancestral cell by mitosis in eukaryotes or by binary fission in prokaryotes. Clone cells also include populations of recombinant DNA molecules all carrying the same inserted sequence. (From King & Stansfield, Dictionary of Genetics, 4th ed)	Clones,Cell, Clone,Cells, Clone,Clone,Clone Cell
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
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
D000953	Antigens, Protozoan	Any part or derivative of any protozoan that elicits immunity; malaria (Plasmodium) and trypanosome antigens are presently the most frequently encountered.	Protozoan Antigens
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
D014122	Toxoplasma	A genus of protozoa parasitic to birds and mammals. T. gondii is one of the most common infectious pathogenic animal parasites of man.	Toxoplasma gondii,Toxoplasma gondius,Toxoplasmas,gondius, Toxoplasma
D015496	CD4-Positive T-Lymphocytes	A critical subpopulation of T-lymphocytes involved in the induction of most immunological functions. The HIV virus has selective tropism for the T4 cell which expresses the CD4 phenotypic marker, a receptor for HIV. In fact, the key element in the profound immunosuppression seen in HIV infection is the depletion of this subset of T-lymphocytes.	T4 Cells,T4 Lymphocytes,CD4-Positive Lymphocytes,CD4 Positive T Lymphocytes,CD4-Positive Lymphocyte,CD4-Positive T-Lymphocyte,Lymphocyte, CD4-Positive,Lymphocytes, CD4-Positive,T-Lymphocyte, CD4-Positive,T-Lymphocytes, CD4-Positive,T4 Cell,T4 Lymphocyte
D016176	T-Lymphocyte Subsets	A classification of T-lymphocytes, especially into helper/inducer, suppressor/effector, and cytotoxic subsets, based on structurally or functionally different populations of cells.	T-Cell Subset,T-Cell Subsets,T-Lymphocyte Subset,Subset, T-Cell,Subset, T-Lymphocyte,Subsets, T-Cell,Subsets, T-Lymphocyte,T Cell Subset,T Cell Subsets,T Lymphocyte Subset,T Lymphocyte Subsets
D016827	CD8 Antigens	Differentiation antigens found on thymocytes and on cytotoxic and suppressor T-lymphocytes. T8 antigens are members of the immunoglobulin supergene family and are associative recognition elements in MHC (Major Histocompatibility Complex) Class I-restricted interactions.	Antigens, CD8,Leu-2 Antigens,T8 Antigens, T-Cell,CD8 Antigen,Antigen, CD8,Antigens, Leu-2,Antigens, T-Cell T8,Leu 2 Antigens,T-Cell T8 Antigens,T8 Antigens, T Cell