Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Cytotoxic T lymphocyte”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1978

Lymphocyte cytotoxicity in the X-irradiation induced rat small bowel adenocarcinoma. II. Presence of cytotoxic lymphocytes in irradiated animals.

Cytotoxic peripheral blood lymphoid cells were demonstrated in both Holtzman and Lewis Brown-Norway rats which had received 2000R of local X-irradiation to the temporarily hypoxic, exteriorized, ileum and jejunum regardless of whether a small bowel adenocarcinoma subsequently developed. The cytotoxic response, which was detectable at two days, was quite evident by day 5 post-irradiation. No evidence of cross-reacting tumor antigens was obtained when similarly processed effector cells from Holtzman rats bearing a spontaneous mammary carcinoma were incubated with cell cultures derived from the small bowel adenocarcinoma. These findings indicate X-irradiation of the small bowel initiates lymphocyte sensitization that is manifested as in vitro cytotoxicity against cell cultures of the adenocarcinoma.

Adenocarcinoma↗
PubMed1976

In vitro induction of cell-mediated immunity to murine leukemia cells. I. Optimization of tissue culture conditions for the generation of cytotoxic lymphocytes.

Cytotoxic lymphocytes (CTL) to allogeneic and syngeneic murine leukemia cells were generated in vitro in "one way" mixed lymphocyte-tumor cell cultures carried out under a variety of conditions. In an attempt to define the optimal culture conditions for sensitization, the following parameters were analyzed: culture vessel, culture volume, responder: stimulator (R:S) cell ratio, lymphoid cell density, source of lymphoid cells, duration of culture, fetal calf serum (FCS) concentration, 2-mercaptoethanol (2-ME) concentration, concentration of amino acids, and buffering system. Of the many variables examined, of particular importance were the R:S cell ratio, the cell density, the FCS concentration, the presence of 2-ME, and the time of harvesting. These factors exerted various effects, both quantitatively and qualitatively, on the magnitude and kinetics of the responses induced in microcultures (5 X 10(6) lymphocytes) and macrocultures (25 X 10(6) lymphocytes). Moreover, optimal sensitization in syngeneic cultures required different conditions than those for allogeneic cultures. Cytotoxic activity was assessed in vitro by a quantitative 51Cr-release assay. The sensitized lymphocytes demonstrated the characteristics ofT lymphocytes and reacted specifically with the sensitizing leukemia cells.

Animals↗
PubMed1979

Demonstration of cytotoxic lymphocytes to virus-infected target cells in pigs inoculated with transmissible gastroenteritis virus.

Lymphocytes, cytotoxic to virus-infected target cells, were induced in pigs orally exposed to transmissible gastroenteritis virus. They were studied and experiments were carried out by using autochthonous testicle cells as target cells to avoid genetic incompatibility of effector lymphocytes and target cells. Cytotoxic lymphocytes were demonstrated in Peyer's patches, mesenteric lymph nodes, spleen, and peripheral blood on postinoculation day (PID) 7. Cytotoxic activity of lymphocytes increased thereafter and reached the maximal amount at PID 21. Lymphocyte cytotoxicity was somewhat greater in lymphocytes of peripheral blood and spleen than in those of Peyer's patches and mesenteric lymph nodes after PID 14. On the contrary, lymphocyte reactivity to the viral antigen measured by lymphocyte proliferative assay was higher in Peyer's patch and mesenteric lymph node cells than in peripheral blood and splenic cells. Lymphocyte cytotoxicity was depressed by treating effector cells with anti-porcine thymocyte serum and complement. However, lymphocyte suspensions treated with anti-porcine thymocyte serum and complement were still cytotoxic to some extent against virus-infected target cells, although T lymphocytes were completely excluded by the treatment. This suggests that cytotoxic mechanism other than the direct action of cytotoxic T lymphocytes may be involved in the cytotoxicity assay systems used in the present studies. In experiments in which allogenic cells (testicle cells of siblings) were used together with autochthonous cells as targets, lymphocyte cytotoxicity was equally expressed against both autochthonous and allogenic target cells in 2 of 3 experiments. However, lymphocyte cytotoxicity was greater against autochthonous cells than against allogenic target cells in 1 of 3 experiments.

Animals↗
PubMed1977

In vitro generation of tumor-specific cytotoxic lymphocytes. Secondary allogeneic mixed tumor lymphocyte culture of normal murine spleen cells.

In vivo or in vitro immunity to murine leukemia virus (MuLV)-induced leukemia cells which do not effectively produce virus, has been difficult to demonstrate. Because immunizations with allogeneic murine leukemia cells have been used to confer syngeneic tumor immunity to virus- producing cells, we attempted to generate lymphocytes, cytotoxic to syngeneic nonproducer leukemia cells, by stimulating normal murine spleen cells with allogeneic nonproducer leukemia cells in mixed tumor lymphocyte culture (MTLC) reactions in vitro. Secondary allogeneic MTLC of normal C57BL/6 or DBA/2 spleen cells effectively produced syngeneic tumor-specific cytotoxic lymphocytes. Target cells lysed in lymphocyte- mediated cytolysis (LMC) assays, included both Friend and Rauscher virus- induced syngeneic murine leukemia cells and chemically-induced hematopoietic tumor cells. Syngeneic tumor cells were lysed regardless of whether they produced infectious MuLV or expressed viral antigens gp-71, p-30, or p-12 at the cell surface. Syngeneic normal cells (thymus, lymph node, or Concanavalin A-stimulated spleen cells) used as targets in LMC assays were uneffected by lymphocytes harvested from secondary allogeneic MTLC. Several other in vitro culture treatments including secondary syngeneic MTLC and repetitive mixed lymphocyte culture stimulations were incapable of generating tumor-specific cytotoxic lymphocytes. Based upon these results, we propose that secondary MTLC stimulation of normal spleen cells with allogeneic nonproducer leukemia cells selects for the proliferation of two subpopulations of antigen-specific cytotoxic lymphocytes. The population capable of effecting syngeneic tumor cell lysis is directed against tumor-associated cell surface antigens which may be distinct from viral structural proteins or glycoproteins. The growth of these tumor-specific cytotoxic lymphocytes may be enhanced by a soluble allogeneic effect factor produced by the proliferation of the second subpopulation of lymphocytes generated in repetitive allogeneic MTLC, namely those lymphocytes with specificities directed against differing histocompatibility antigens.

Animals↗
PubMed1979

Development in vitro of cytotoxic lymphocytes against murine cytomegalovirus.

Lymphocytes cytotoxic for mouse embryo fibroblasts (MEF) infected with murine cytomegalovirus (MCMV) were produced by in vitro culture of "memory" spleen cells with UV-irradiated, MCMV-infected, MEF. Cytotoxic lymphocytes were developed from spleen cells of mice 10 to 240 days after infection with MCMV. The cytotoxic cells carried the theta and Ly 2 antigens, and were H-2 restricted in the recognition of infected target cells.

Animals↗
PubMed1977

Clones of cytotoxic lymphocytes in culture: the difference in specificity between stimulated and nonstimulated cytotoxic lymphocytes.

The specificity of individual clones of cytotoxic lymphocytes (CL) which develop upon stimulation by semi-allogeneic cells, have been examined and compared with the specificity of CL clones which develop spontaneously when normal spleen cells are cultured without stimulator cells. It was found that the specificity of stimulated clones was different from the specificity of 'spontaneous' clones. Specifically stimulated clones from CBA cells cultured with (CBA x DBA)F1 stimulator cells, did not discriminate between the H2dP815 and H2dDBA splenic blast, and lysed both targets. In contrast, spontaneous CL clones from cultures of CBA or (CBA x DBA)F1 spleen cells were found to lyse either P815 or DBA blast, but not both. The results indicated that the spontaneous CL clones were not a representative sample of the the total pool of CL.

Animals↗
PubMed1977

Concanavalin A-mediated activation of antigen-primed lymphocytes into secondary cytotoxic lymphocytes.

A secondary specific cytotoxic response is obtained when lymphocytes primed in vivo to a tumor allograft are exposed to Con A in culture. The secondary cytotoxic cells generated are specific to target cells bearing antigens of the primary sensitizing cells and are qualitatively indistinguishable from the response obtained upon secondary antigenic stimulation. The cell-mediated cytotoxicity is independent of concanavalin A (Con A) and is not affected by the Con A-specific inhibitor, alpha-methyl-D-mannose pyranoside. Furthermore, cultures containing a mixture of submitogenic concentrations of Con A and stimulating antigens showed synergy and augmentation of cytotoxic activity. It is suggested that activation of prekiller cells by Con A into CTL may be mediated via the same or similar receptors normally triggered by the stimulating antigens. Functional similarities between ConA and the lymphocyte-defined antigens of the major histocompatibility complex region are discussed.

Animals↗
PubMed1978

Cell-mediated lympholysis: examination of HLA genetic fine structure and complementation using cytotoxic lymphocytes.

Human cytotoxic lymphocytes (CTL), sensitized in vitro in one-way mixed lymphocyte cultures between two unrelated individuals, have been used to study target cell determinants. One pair of CTL shows strong cell-mediated lympholysis responses against the specific target cells as well as against third-party target cells obtained from unrelated individuals. Testing of sixty target cells shows a significant association between the two CTL with a correlation coefficient of 0.67 in the panel. The target determinant recognized by the CTL is not an HLA-A,B,C or D specificity, as defined by standard serological and cellular reagents. Segregation studies in a large family reveal that the new specificity defined by the CTL is controlled by HLA, and its recognition may be restricted by the HLA complex.

Cytotoxicity Tests, Immunologic↗
PubMed1979

The in vitro effects of Bordetella pertussis lymphocytosis-promoting factor on murine lymphocytes. IV. Generation, characterization, and specificity of cytotoxic lymphocytes.

Cytotoxic effector lymphocytes were induced in cultures of mouse spleen or lymph node cells by lymphocytosis promoting factor (LPF). The LPF-activated cytotoxic cells: (a) were not generated unless proliferation occurred; (b) sedimented in the lighter density fraction of a bovine serum albumin gradient; (c) were large, blast-like cells; and (d) were lysed by Thy-1.2 antiserum plus complement and, therefore, were T cells. Neither LPF alone nor supernates from stimulated cultures were cytotoxic. Unlike the situation with concanavalin A and phytohemagglutinin P, LPF-stimulated cytotoxic effector lymphocytes required no further addition of mitogen for maximal cytotoxicity. The effector cells displayed specificity, destroying only allogeneic but not syngeneic normal cells; in the case of tumor cells, both allogeneic and syngeneic cells werelysed in the absence of added mitogen. The reason for differentiated cytotoxicity toward syngeneic tumor and normal cells is not clear but may have some relevance to in vivo tumor rejection initiated by Bordetella pertussis.

Animals↗
PubMed1978

Suppression of human cytotoxic lymphocytes by methylprednisolone. An immunosuppressive mechanism of action of steroids.

In order to gain insight into the immunosuppresive mechanism of action of corticosteroids, an in vitro model of the cellular immune response was used to study the effect of methylprednisolone on human lymphocyte-mediated cytotoxicity. Concentrations from 0.25 to 10 microgram/ml were equally effective in producing 74% suppression lymphocyte-mediated cytotoxicity when the steroid was present during the entire period of in vitro sensitization. A 12.5-fold increase in effector to target cell ratio was required to achieve 30% 51Cr release when cytotoxic lymphocytes were generated in the prescence of methylprednisolone. Lymphocyte-mediated cytotoxicity was suppressed 48% when methylprednisolone was present only during the initial 24 hr of the 7-day in vitro sensitization period. Methylprednisolone also effectively inhibited cytotoxicity when it was incubated with sensitized lymphocytes for 3hr before incubating these cells with target cells. Our observations suggest that two of the major immunosuppressive mechanisms of action methylprednisolone are suppression of the generation of cytotoxic lymphocytes and suppression of specifically sensitized cytotoxic lymphocytes.

Cytotoxicity Tests, Immunologic↗
PubMed1976

Cytotoxic lymphocytes in infectious mononucleosis.

Seven patients with a clinical diagnosis of infectious mononucleosis (IM) and detectable heterophil antibodies were found to have peripheral blood lymphocytes that were cytotoxic for lymphoid cells containing Epstein-Barr virus from a patient with Burkitt's lymphoma. The cytotoxic lymphocytes persisted in the peripheral circulation for up to 45 days. Patients who had had IM 1 to 5 years previously lacked such cytotoxic lymphocytes. Patients who had signs and symptoms of IM but no detectable heterophil antibodies lacked cytotoxic lymphocytes. The lymphocytes of one patient with IM showed progressive diminution of cytotoxic ability after prednisone treatment.

Adult↗
PubMed1976

Cell mediated lympholysis in man: an attempt to type with cytotoxic lymphocytes.

From approximately 3,000 CML combinations, originally established in order to evaluate the qualitative and quantitative influence of the serologically defined HLA-A, B, and C antigens on cellular, complement independent cytolysis, 12 combinations were selected yielding reproducible positive cytolysis on allogenic target cells, although no HLA-antigenic sharing could be demonstrated between stimulator and target lymphocytes. These 12 CytoToxic Lymphocytes (CTL's) have been tested in parallell as "CML typing combinations" against lymphocytes from a random population sample of 100 unrelated Danes. Based on a pairwise analysis 11 of these CTL's could be classified into two groups of significantly correlated CTL's. These two groups do not define monospecific traits of allelic genetic origin as judged by a mutually positive correlation and a poor fit to Hardy-Weinberg equilibrium. The traits defined by these groups may be either partially identical or governed by closely linked loci. The same groups were identified and the same conclusions reached after exclusion of those individuals in the population sample where HLA-A, B, C, or D antigens may be targets for destruction. Thus, this study gives direct evidence that known HLA antigens are not sole target determinants in CML or that cytotoxic lymphocytes recognize HLA molecules in a different way than lymphocytotoxic antibodies. The studies underline the immunogenetic complexity of CML although this reaction is most probably governed by genes in the HLA region. It is suggested that cytotoxic lymphocytes may recognize "backbone structures" of the HLA molecules.

Cytotoxicity Tests, Immunologic↗
PubMed1978

In vitro lymphocyte stimulation and the generation of cytotoxic lymphocytes with drug-induced antigenic lymphomas.

New antigenic specificities, not detectable on parental cells and transmissible after the withdrawal of the drug treatment, have been induced in mouse lymphomas. Studies were conducted of proliferative stimulation of syngeneic lymphocytes and the generation of cytotoxic lymphocytes (CL's) in a mixed lymphocyte-tumor cell culture system by 5-(3,3-dimethyl-1-triazeno)imidazole-4-carboxamide (DTIC)-induced antigens in L1210 and EL4 leukemia sublines. The DTIC-induced antigens were observed to stimulate [3H]thymidine uptake by normal and primed syngeneic lymphocytes and to generate specific CL's to DTIC-altered cells. The specificity of the in vitro immune reactivity was demonstrated. Characteristics of lymphocyte triggering, including the optimal ratio of stimulating cells to responding cells, the kinetics of CL activation, and the quantitation of CL activity, were also evaluated. DTIC antigens on leukemic cells can activate syngeneic lymphocytes and can act as target antigens in cell-mediated immunity. The experimental data support the transplantation antigen-like nature of DTIC-induced antigens.

Animals↗
PubMed1975

Cytotoxic lymphocytes from normal donors. A functional marker of human non-T lymphocytes.

A phenomenon we have termed spontaneous lymphocyte-mediated cytotoxicity (SLMC) by non-thymus-derived lymphocytes from normal donors has been described. The phenomenon can be demonstrated using human and xenogeneic (mouse) cell lines as the target cell in a microplate 51Cr release assay which is simple and reproducible. In this paper, SLMC against xenogeneic targets has been evaluated as a potential marker of lumphocytotoxic function with respect to: (a) the nature of the target cell; (b) the variability of the cytotoxic function of lymphocytes from different donors, and from the same donor tested on different days; (c) the nature of the effector cell. Using buoyant density centrifugation of iron plus magnetpurified lymphocytes forming rosettes with sheep red blood cells (SRBC) (T-cells) or SRBC-rabbit 19S anti-SRBC-mouse complement (complement receptor lymphocyte), it has been demonstrated that the cytotoxic activity lies in the non-T-lymphocyte fraction, and is probably caused by the complement receptor-bearing lymphocyte. The potential usefulness of this phenomenon as a functional marker of non-T-LYMPHOCYTE CYTOTOXIC Ability, and for the assessment of serological factors ehich may affect this cytotoxicity, has been discussed.

Animals↗
PubMed1977

Lymphocyte cytotoxicity in alcoholic hepatitis.

Studies were undertaken to evaluate the cytotoxicity of peripheral lymphocytes obtained from patients with alcoholic hepatitis. Lymphocyte cytotoxicity to Chang liver cells was investigated by a microcytotoxicity test, and that to autologous liver cells obtained by percutaneous liver biopsy was studied using a 51Cr release assay. Lymphocytes from patients with alcoholic hepatitis were found to be highly cytotoxic to Chang liver cells and autologous liver cells when compared to those of healthy subjects (P is less than 0.001). Cell-free supernatant fluid of lymphocytes from patients with alcoholic hepatitis incubated with purified alcoholic hyalin for 5 days was significantly cytotoxic to Chang liver cells (P is less than 0.01), indicating that a cytotoxic factor is elaborated by sensitized lymphocytes. A significant reduction in cytotoxicity was noted with disappearance of clinical features or direct addition of a purified isolate of alcoholic hyalin or its preincubation with lymphocytes. Preincubation of sensitized lymphocytes with acetaldehyde increased cytotoxicity for autologous liver beyond that obtained by the combined effects of lymphocytes alone and acetaldehyde alone (P is less than 0.001), interpreted as evidence that ethanol toxicity and hyperactivity of lymphocytes independently and collectively contribute to development of cirrhosis in patients with alcoholic hepatitis who continue to imbibe alcohol.

Acetaldehyde↗
PubMed1978

Generation of cytotoxic lymphocytes in the autologous mixed lymphocyte culture.

We have studied the ability of purified B lymphocytes to generate cytotoxic T lymphocytes in autologous mixed leukocyte cultures (MLC). Cytotoxic lymphocytes were produced but only autologous mononuclear cells stimulated by lipopolysaccharide (LPS) were susceptible target cells. Unstimulated mononuclear cells and purified B cells were not susceptible to killing by cytotoxic cells generated in the autologous MLC. This suggests that the target antigen may be expressed on stimulated or dividing B lymphocytes in a way that renders the cells more susceptible to cytolysis. Autologously stimulated cytotoxic effector cells were found to exhibit specificity. Cy totoxicity for autologous LPS-stimulated target cells occurred but not for an allogeneic, B cell, histiocytic lymphoma cell line. It is postulated that cytotoxic T cells generated in the autologous MLC may play a role in immune surveillance or in regulation of the immune system.

B-Lymphocytes↗
PubMed1979

Lung tumor-reactive cytotoxic lymphocytes generated in mixed lymphocyte reaction between C3HfeB/HeN (H-2kb) and C3H/HeN (H-2k) strain mice.

The tumor-associated transplantation antigen expressed by several transplacentally induced lung tumors of C3HfeB/HeN mice (H-2kb haplotype) has previously been shown to exist as a normal tissue alloantigen in mice of known H-2k and H-2a haplotypes. This antigen is not expressed in normal tissues of C3HfeB/HeN mice but is expressed in C3H/HeN mice, the strain from which the C3HfeB/HeN mice were originally derived. The present study indicates that spleen cells from C3HfeB/HeN and C3H/HeN mice respond reciprocally in the mixed lymphocyte reaction. Cytotoxic T lymphocytes specific for the tumor-associated alloantigen can be readily generated in mixed lymphocyte reactions in which spleen cells from C3HfeB/HeN mice are reacted with x-irradiated spleen cells from C3H/HeN or A strain mice. These cells are effective in suppressing the growth of the C3HfeB/HeN-derived lung tumor 85 in x-irradiated syngeneic recipients.

Animals↗