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Results for “Cytotoxicity Tests, Immunologic”

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At least 19 recordsLinked to original sources
PubMed1975

[The lymphocyte cytotoxicity test in tumor immunology (author's transl)].

The cytotoxic action of lymphocytes on cancer cells in vitro indicates sensitization of the patient against his own tumor. The technical difficulities of this test and possibilities of standardization and simplifying the procedure are discussed. Critical steps are isolation of lymphocytes and culturing target cells without loosing their specific antigenic structure. The need for specificity controls both for lymphocytes and tumor cells is emphasized. Labelling tumor cells with isotopes represents a major improvement in evaluating the result. The role of thymus- and bone marrow-dependent lymphocytes as well as blocking factors in the serum of tumor patients can be analyzed in the cytotoxic assay. A better understanding of these mechanisms may facilitate a therapeutic approach by manipulating the interaction of tumor cells and host.

Animals↗
PubMed1979

Decreased cell-mediated cytotoxicity against virus-infected cells in systemic lupus erythematosus.

Cell-mediated cytotoxicity, directed against virus-infected tissue culture cells, was studied with peripheral blood mononuclear cells from 11 patients with systemic lupus erythematosus (SLE) and 12 matched, normal subjects in a 51Cr release assay. Baseline (preimmunization) levels of cytotoxicity against target cells infected with influenza A/Victoria, influenza B/Hong Kong, Newcastle disease virus, and herpes simplex virus were significantly decreased in patients with SLE compared to normal subjects (P less than 0.001), although serum antibody levels to the respective viruses were similar in both groups. After intramuscular administration of inactivated influenza A/Victoria vaccine, SLE patients failed to generate elevated levels of cytotoxicity against A/Victoria-infected cells, in contrast to normal subjects. SLE patients responded with levels of serum hemagglutination-inhibition antibody which were similar to those of normal subjects. Thus, SLE patients manifest decreased cell-mediated cytotoxicity against virus-infected target cells, although humoral antibody responses appeared to be intact. Studies of SLE patients with influenza may help to define the role of cell-mediated immunity in the pathogenesis of certain viral infections.

Adolescent↗
PubMed1978

The role of methylprednisolone in the modulation of cellular cytotoxicity and its relation to renal transplantation.

Inhibition of killer cell generation or suppression of their cytolytic capacity once formed represent fundamental mechanisms by which methylprednisolone may modulate cellular cytotoxicity in the transplant recipient. In vitro studies in mixed lymphocyte culture demonstrated that the presence of therapeutic concentrations of this agent (0.001-1 microgram/ml) during the sensitisation phase resulted in suppression of lymphocyte activation without cytolysis and marked or total inhibition of killer cell generation. A considerable individual variation in sensitivity to methylprednisolone-induced suppression was observed and killer cells once generated were resistant to this agent.

Cytotoxicity Tests, Immunologic↗
PubMed1977

Immunological diagnosis of rejection in human renal allotransplanted patients--a prospective study.

The object of this study has been to evaluate the recipient's immunological reactivity towards donor lymphocytes in relation to rejection episodes. All recipients (20) of local necrokidneys during 1976 were immunologically monitored immediately before transplantation and subsequently twice weekly for donor-specific complement dependent lymphocytotoxic (CDC) antibodies, antibody dependent cell-mediated cytotoxicity (ADCC) and cell-mediated lympholysis (CML). Experiments were performed until graft removal or dismissal (approx. 1100 patient days). Clinical diagnosis of rejection was made independently of immunological results. All clinically suspected rejection episodes, except one, were checked by microscopy. A positive CML-test accompanied 9 out of 11 rejection episodes; the test was negative on all other occasions. Positive CDC and ADCC tests exhibited no obvious correlation with rejection episodes: positive ADCC may be more frequent in clinically uncomplicated phases. Positive CML did not generally precede clinical graft rejection. Positive CML before transplantation was observed in two cases and was followed by irreversible, accelerated acute rejections. The CML-test may prove a reliable tool in rejection diagnosis and may yield results comparable with graft biopsy without inflicting any risk on the patient.

Antibodies↗
PubMedDate not supplied

Natural killer and tumor recognizing lymphocyte activity in tumor patients.

Several mechanisms can lead to the killing of a target cell by lymphocytes. In order to study immunologically specific phenomena it has to be ensured that the natural killer (NK) effect does not operate in the system. Using targets which are sensitive to NK, the effector populations have to be depleted of lymphocytes with such potential. The blood lymphocytes of tumor carrying patients often have reduced NK activity. In two assay systems anti-tumor autoimmune reactivity has been demonstrated (the majority of tested patients had lung carcinomas or osteosarcomas). The tests were: 1. Induction of blastogenesis in blood lymphocytes by in vitro confrontation with autologous biopsy cells. 2. Lymphocyte mediated killing of autologous biopsy cells in short term in vitro assay. Cross reactivity between patients was rare which indicates either that the putative tumor antigens are individual specific or their recognition is restricted by histocompatibility.

Animals↗
PubMed1978

Immunopathologic studies of rheumatoid arthritis. I. Absence of complement-dependent cytotoxicity of rheumatoid sera for rheumatoid synovial cell cultures.

A sensitive complement-dependent chromium release cytotoxicity assay was used to determine whether sera from rheumatoid arthritis (RA) patients contain antibody specific for an antigen on rheumatoid synovial cell cultures. Two hundred eight RA sera-RA synovial culture combinations were studied employing 21 sera and 16 synovial membranes; control combinations were derived from 5 normal sera and 10 degenerative joint disease synovial membranes. Anticomplementary activity of some rheumatoid sera was overcome using an increased complement concentration. The percent cytotoxicity of RA serum-RA culture combinations, both homologous and autologous, was not significantly greater than that of RA serum-control culture combinations. No correlation between duration of disease or duration of cell culture and percent cytotoxicity was found. Thus a unique antigen on cultured rheumatoid synovial cells was not recognized by rheumatoid serum antibody by use of this cytotoxicity assay.

Adolescent↗
PubMed1978

Colony formation of cytolytic T cells in semisolid medium.

Addition of supernatant from concanavalin A-stimulated spleen cells to in vitro primed cytolytic T lymphocytes in semisolid medium stimulated the growth of colonies of cytolytic lymphocytes. Optimal results were obtained using a peritoneal adherent cell underlayer where a 10% plating efficiency (greater than or equal to 4 cells per colony) was achieved when between 5000 and 100 000 cells were plated per dish. Individual colonies were harvested and tested in a short term (5h) 51Cr release microassay, employing 200 target cells. The frequency of lytic colonies varied from 46--67%. The observed lytic activities were specific for the relevant allogeneic target cells.

Animals↗
PubMed1978

Influenza virus-specific cytotoxic T cells in man; induction and properties of the cytotoxic cell.

Human peripheral blood lymphocytes have been sensitized in vitro to influenza virus antigen. After an induction period of 4--14 days, cytotoxic cells which lyse autologous influenza virus-infected lymphoid cells could be demonstrated. The cytotoxic cell is a T lymphocyte which shows specificity for sensitizing influenza virus type A or B. It cannot distinguish between major subtypes of influenza A virus. The use of virus-infected normal lymphoid cells as target cells overcame the difficulties of nonspecific killing encountered with some transformed cells.

Cytotoxicity Tests, Immunologic↗
PubMed1979

High nonspecific reactivity of normal lymphocytes against mycoplasma-infected target cells in cytotoxicity assays.

Several rat tumor cell cultures were deliberately infected with three species of mycoplasma commonly found as contaminants of cell lines grown in vitro, and the effect of mycoplasma infection on the results of cytotoxicity assays was examined. Lymph node cells and spleen cells from normal animals showed an apparently high spontaneous cytotoxic activity against tumor cells infected with either M. arginini or M. hyorhinis, but the reactivity against cells infected with M. orale was not significantly higher than that against uninfected cells. The high reactivity towards tumor cells infected with M. arginini and M. hyorhinis bore a close resemblence to natural cell-mediated immunity in that spleen cells were much more reactive than lymph node cells, spleen cells from nude mice were as effective as spleen cells from normal mice, and the reaction crossed both strain and species barriers. However, closer examination revealed that the cytotoxic effects were directly caused by depletion of arginine or other essential nutrients from the medium. These findings imply that a cautious approach should be taken when interpreting certain aspects of spontaneous cell-mediated cytotoxicity, and that the greatest care be taken to ensure that the cells used as targets in any cytotoxicity test are mycoplasma-free.

Animals↗
PubMed1977

Tumor-associated humoral cytotoxicity in patients with acute myelogenous leukemia before and after chemotherapy.

Sera of eight unselected adult patients with acute myelogenous leukemia obtained before and after chemotherapy were repeatedly tested for specific complement-dependent cytotoxicity against autochthonous peripheral white blood cells from the acute leukemia stage and from the remission stage, respectively. Complement-dependent cytotas demonstrated in all of the eight patients, while none of three patients' sera were reactive against white blood cells from the remission stage tested in parallel. The cytotoxicity was increased after chemotherapy, also in those patients in whom remission was not achieved.

Adult↗
PubMed1978

Human natural cytotoxicity in the blood and lymphoid organs of healthy donors and patients with malignant disease.

Natural cytotoxicity against CLA-4 and D6 target cells was determined in the peripheral blood of healthy donors and women with mammary carcinoma (localized to the breast and axilla), and in human normal and regional tumour lymph nodes. The NK cell activity in the blood of women with clinically localized mammary carcinoma showed a wide range of reactivities but was similar to the pattern detected in healthy controls. The NK cell activity in human normal lymph nodes also showed a wide range and was the same irrespective of the anatomical site of origin of the lymph node. Lymph nodes draining a variety of solid tumours had a similar spectrum of NK cell activity, there being no obvious correlation between the level of NK cell activity and such parameters as size and histological type of tumour, hyperplasia or metastatic spread in the regional node. Trypsin treatment of lymphocyte suspensions from the various lymphoid compartments suggested that the cell responsible for natural cytotoxicity in blood was probably different from the NK cell in tonsil and lymph nodes.

Adult↗
PubMed1978

Characterization of the human natural killer (NK) cell in blood and lymphoid organs.

The human natural killer (NK) cell in peripheral blood is a non-thymus-dependent, (Fc+ C3-), Ig-bearing lymphocyte and is probably identical to the human K cell, although not requiring the Fc receptor, in contrast to the K cell, for the lytic process. The human NK cell in tonsil and lymph node, on the other hand, is a non-Ig- bearing T lymphocyte, lacking both Fc and C3 receptors.

Cell Migration Inhibition↗
PubMed1979

Cell-mediated reactivity to antigens shared by Moloney-virus-induced lymphomas (LSTRA) and certain 3-methylcholanthrene-induced mouse sarcomas.

Spleen cells (SC) both from BALB/c mice whose primary Moloney sarcoma virus (MSV)-induced sarcomas had spontaneously regressed and from normal, untreated BALB/c mice, were co-cultivated for 5 days with mitomycin-C-treated LSTRA cells; LSTRA is a BALB/c Moloney lymphoma which shares cell surface antigens with MSV-indiced sarcomas. These SC, referred to as CMR and CU cells, respectively, were shown to be cytotoxic to LSTRA cells in 3 h 51Cr-release assays; CMR cells showed, in most cases, the greatest lytic activity against LSTRA targets. The same SC were also reactive, in 20-h microcytotoxicity and 51Crassays, against target cells from a variety of transplanted sarcomas indiced by 3-methylcholanthrene (MCA) in Balb/c mice. The highest reactivity was seen when CMR or CU cells were tested against target cells from sarcoma lines that expressed an NB-ecotropic MuLV cross-reacting serologically with Moloney virus. Reactivity against isotope-labelled tumor cells expressing MuLV-associated cell surface antigens could be competititively inhibited by adding unlabelled tumor cells expressing such antigens. Finally, Winn assays were performed in which CMR cells strongly inhibited the outgrowth of cells from three sarcoma lines that express the NB-ecotropic MuLV. There was less but significant inhibition of cells from some other MCA sarcomas, either negative for the expression of MuLV-associated antigens or expressing the N-ecotropic endogenous BALB/c MuLV. CU cells enhanced tumor outgrowth in Winn assays at least as often as they inhibited it.

Animals↗
PubMed1978

[Effector function of acute leukemias in "spontaneous" (SCMC) and antibody dependent cellular cytotoxicity-tests (ADCC) (author's transl)].

Blood lymphocytes from 13 untreated acute leukemia patients, 3 pre-leukemias 3 immunoblastic lymphadenopathias and one infectious mononucleosis showed significantly lower spontaneous (SCMC) and antibody-dependent cellular cytotoxicity (ADCC) against 51Cr-labeled allogeneic melanoma cells of the IGR3 cell line than effector lymphocytes from 20 age- and sex matched control persons. While control lymphocytes exhibited the highest cytotoxic activity after depletion of mononuclear phagocytes (Fraction FFF), followed by the "Ficoll" purified Fraction F and defibrinated whole blood, the reverse was true for acute leukemias: here, the highest cytotoxicity was found in whole blood followed by the lymphocyte fractions F and FFF. Comparatively high cytotoxicity was found with two leukemia patients who had received blood transfusions the day before testing. During the course of an acute erythroleukemia chemotherapy drastically reduced SCMC and ADCC activities. A therapeutical splenectomy, on the other hand, did not affect cellular cytotoxicity in the case of a hairy cell leukemia. The angioimmunoblastic lymphadenopathies showed strikingly high percentages of EA- and EAC-rosettes forming cells and showed a marked increase of SCMC and ADCC activities after elimination of mononuclear phagocytes from the effector cell population.

Acute Disease↗