concanavalin-a and Nasopharyngeal-Neoplasms

Telomere length shortening was observed in the nasopharyngeal carcinoma cell CNE-2L2 when 6A8 alpha-mannosidase expression was inhibited by antisense 6A8 DNA. Transduction with mock or an irrelevant DNA did not affect the telomere length in the carcinoma cells. Telomerase activity and mRNA transcription of TRF 1 and 2 were not changed in the cells treated with antisense 6A8. The Con A binding test showed an enhancement on the proteins isolated from the cells treated with antisense 6A8, but not on those from mock- or irrelevant DNA-treated cells. The data imply an association between glycosylation modification with telomere shortening in antisense 6A8-treated cells.

Topics: alpha-Mannosidase; Cell Line, Tumor; Concanavalin A; Glycosylation; Humans; Nasopharyngeal Neoplasms; Nuclear Proteins; TATA Box Binding Protein-Like Proteins; Telomere; Telomeric Repeat Binding Protein 1; Telomeric Repeat Binding Protein 2

An in vitro cytotoxic screening of extracts of Rhaphidophora korthalsii indicated cytotoxicity in the ether fraction. ED50 values of the extract against P388, Molt 4, KB and SW 620 were 12, 14, 8 and 13 micrograms/ml, respectively. The extract was relatively more toxic on P388 and Molt 4 cell lines at concentrations of 50 micrograms/ml and 100 micrograms/ml. Screening with mouse splenocytes showed that the hot water extract had splenocytes stimulating activity.

Topics: Adenocarcinoma; Adjuvants, Immunologic; Animals; Antineoplastic Agents, Phytogenic; Carcinoma, Squamous Cell; Cell Division; Colonic Neoplasms; Coloring Agents; Concanavalin A; Dose-Response Relationship, Drug; Female; Humans; Leukemia; Leukemia P388; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Nasopharyngeal Neoplasms; Plant Extracts; Plant Lectins; Plants, Medicinal; Spleen; Tetrazolium Salts; Thiazoles; Tumor Cells, Cultured; Water

Topics: Adolescent; Adult; Aged; Carcinoma; Concanavalin A; Flow Cytometry; Humans; Leukocyte Count; Lymphocyte Activation; Middle Aged; Nasopharyngeal Neoplasms; T-Lymphocytes

Depression of mitogenic responses in patients with nasopharyngeal carcinoma (NPC) is well documented. The cause of depression has been supposed to be the presence of elevated suppressor cell activity in the peripheral blood of NPC patients. Both spontaneous and Con A-induced suppressor cell activities were examined in 56 pathologically verified NPC patients and 36 age-matched controls. The data showed no alteration of spontaneous or Con A-induced suppressor cell activities in NPC patients. Neither did the quality and quantity of suppressor cell activities correlate with the clinical stage. Therefore the question becomes whether elevated suppressor cell activities might cause the depression of mitogenic responses in NPC patients? Future research on helper cells and intrinsic abnormalities of immune responding cells at the molecular level are suggested.

Topics: Adolescent; Adult; Aged; Carcinoma; Concanavalin A; Female; Humans; Male; Middle Aged; Nasopharyngeal Neoplasms; T-Lymphocytes, Regulatory

The role of larger granular-enriched and depleted lymphocytes was studied in lectin-dependent cell-mediated cytotoxicity (LDCC) against adherent HEp-2 human epipharynx carcinoma target cells. LDCC was evaluated by detachment from the monolayer of 3H-thymidine-prelabelled HEp-2 cells in a 24 h assay at effector-target cell ratios of 25:1 and 50:1 in the presence of 25 micrograms/ml concanavalin A (Con A). Under the aforementioned conditions but in the absence of Con A natural cell-mediated cytotoxicity (NCMC) was not found. However, cytotoxicity was significantly augmented in the presence of Con A (= LDCC) using human peripheral blood mononuclear cells (PBMC) as effectors. Large granular lymphocytes (LGL), which show high natural killer (NK) activity to K 562 target cells, failed to be cytotoxic against HEp-2 targets similar to large granular depleted lymphocytes (LGL-DL). On the other hand, LGL caused only a slight LDCC; whilst LGL-DL induced strong LDCC activity towards HEp-2 targets. In comparison to LDCC using LGL-DL as effector cells, LGL and LGL-DL mixed at a ratio of 1:2, and added to target cells, had no major effect on LDCC, while a lower level of LDCC was observed at LGL/LGL-DL ratios of 1:1, and 2:1, suggesting the dilution of LGL-DL, potential effectors of LDCC to HEp-2 cells, rather than a specific regulatory role of LGL in LDCC. In parallel studies, the proliferation of LGL-DL in response to Con A was less than that observed with PBMC or LGL. The response could be restored by replacing half of LGL-DL per culture with an equal number of LGL, or by the addition of 10% monocytes. Significant functional differences between LGL and LGL-DL in LDCC as well as in Con A-induced blastogenesis are suggested.

Topics: Cell Line; Concanavalin A; Cytotoxicity, Immunologic; Humans; Interferon Type I; Killer Cells, Natural; Lymphocyte Activation; Lymphocytes; Nasopharyngeal Neoplasms

Topics: Cell Line; Cell Transformation, Neoplastic; Concanavalin A; Hot Temperature; Humans; Nasopharyngeal Neoplasms; Phenotype

The mitogenesis of lymphocyte subpopulations in response to phytohemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM) were studied in 75 patients with nasopharyngeal carcinoma (NPC) and in 51 healthy controls. The net increments of isotope incorporation of either T cells or B cells in NPC patients with PHA, Con A or PWM stimulation were far less than those in controls, with statistical significance (p less than 0.001) respectively. However, there was no link between the mitogenesis and the clinical stage. It is concluded that it is of doubtful value to use quantitative mitogenesis in NPC patients as a prognostic indicator. A study of loco-regional immune response is suggested.

Topics: Adult; B-Lymphocytes; Concanavalin A; Humans; Immunity, Cellular; Lectins; Lymphocyte Activation; Lymphocytes; Middle Aged; Nasopharyngeal Neoplasms; Phytohemagglutinins; Pokeweed Mitogens; T-Lymphocytes

The role of OKT4+ and OKT8+ T-cell subsets was studied in lectin-dependent cell-mediated cytotoxicity (LDCC) against adherent HEp-2 human epipharynx carcinoma target cells. LDCC was evaluated by detachment from the monolayer of [3H]thymidine prelabeled HEp-2 cells in a 24-hr assay with a concanavalin A (Con A) dose of 25 microgram/ml at effector:target cell ratios of 5:1, 25:1, and 50:1. Under these conditions but without Con A considerable natural cell-mediated cytotoxicity (NCMC) was not elicited; however, the cytotoxicity was significantly augmented in the presence of Con A (=LDCC) by sheep erythrocyte rosette-forming T lymphocytes and by both OKT4+ and OKT8+ T-cell fractions. LDCC activity by isolated OKT8+ T cells was superior to that by OKT4+ T cells and unfractionated T lymphocytes. By contrast, addition of either OKT4+ or OKT8+ T cells together with unfractionated T lymphocytes, or OKT4+ and OKT8+ T cells mixed at ratios of 1:1, 1:2, and 2:1, to target cells did not result in major differences in comparison of LDCC activities by these mixed effector cell populations with each other or with that by unfractionated T lymphocytes. Parallel studies were carried out to determine the effect of OKT4+ and OKT8+ T-cell subsets on the Con A-induced proliferation of peripheral blood mononuclear cells (PBMC). While OKT8+ T cells inhibited the mitogenic response to Con A, OKT4+ T lymphocytes had no major effect. A higher responsiveness of the OKT8+ to OKT4+ T-cell subset in LDCC to HEp-2 targets and in Con A-induced lymphocyte proliferation is suggested.

Topics: Antibodies, Monoclonal; Carcinoma; Cell Line; Cell Separation; Concanavalin A; Cytotoxicity, Immunologic; Humans; Lymphocyte Activation; Nasopharyngeal Neoplasms; Phenotype; T-Lymphocytes, Helper-Inducer; T-Lymphocytes, Regulatory

A new technique for the detection of glycoprotein antigens in immune complexes (IC) isolated from serum is described. The technique was developed with a model IC system consisting of ovalbumin (OVA)-rabbit anti-ovalbumin antibodies (aOVA), at 3 times antigen excess. OVA-aOVA IC added to normal human serum (NHS) were purified by absorption onto and elution from tubes coated with rheumatoid factor (RF) and were subjected to electrophoresis in polyacrylamide gels. Concanavalin A (Con A)-binding proteins were detected by treating the gels with radioiodinated Con A (125Con A), followed by autoradiography. IC isolated from sera of patients with Burkitt's lymphoma (BL) and Nasopharyngeal Carcinoma (NPC) were analyzed before and after reduction with dithiothreitol. Two closely spaced proteins of about 40 kdalton were identified in the reduced samples in 26 of 30 BL sera (86%) and in 24 of 30 NPC sera (80%) but were not seen in 30 sera of African patients with a variety of unrelated tumors nor in 12 sera of European blood bank donors.

Topics: Antigen-Antibody Complex; Antigens, Neoplasm; Burkitt Lymphoma; Carcinoma; Concanavalin A; Glycoproteins; Humans; Molecular Weight; Nasopharyngeal Neoplasms; Prognosis

Con A-Sepharose affinity chromatography may be used in the analysis and classification of immune complexes. Experiments with model immune complexes suggest that the degree of affinity of an immune complex for Con A-Sepharose is determined by the antigen rather than the IgG antibody of the complex. It is possible that partial characterization of unknown antigens linked to IgG in immune complexes may be achieved in many diseases. Preliminary explorations with selected human sera indicate that the IgG containing immune complexes in Burkitt's lymphoma and nasopharyngeal carcinoma have affinity for Con A-Sepharose. By contrast IgG containing immune complexes in chronic hepatitis B seem to lack affinity for Con A-Sepharose.

Topics: Antigen-Antibody Complex; Burkitt Lymphoma; Chromatography, Affinity; Chronic Disease; Concanavalin A; Hepatitis B; Humans; Immune Sera; Immunoglobulin G; Nasopharyngeal Neoplasms; Sepharose

Eighteen patients with nasopharyngeal carcinoma (NPC) were compared to matched controls, before or after cobalt therapy, for the ability of their peripheral blood lymphocytes to: (1) form E and EAC rosettes and (2) mount a proliferative response with PHA, Con A and ALG. A slight decrease in the percentage of E rosettes and a moderate hyporesponsiveness to PHA and Con A were observed before treatment. The statistical significance of these alterations was borderline. Within the group of treated patients a much greater depression, including the response to ALG, was found, although a few long-term survivors responded to mitogens as well as the controls. These findings stress the difficulty of interpreting the results of a longitudinal study of cell-mediated immunity, specific or non-specific, in cancer patients. Finally, by comparing the proliferative response to the three mitogens before and after radiotherapy, it is suggested that their differential effect on these responses might be used in man, as it was in mice, to delineate lymphocyte subpopulations.

Topics: Adult; Aged; Antibodies, Viral; Antilymphocyte Serum; Concanavalin A; Female; Herpesvirus 4, Human; Humans; Lectins; Lymphocyte Activation; Lymphocytes; Male; Middle Aged; Nasopharyngeal Neoplasms; Rosette Formation

Sera of individuals with Burkitt's lymphoma and nasopharyngeal carcinoma, tested by consumption of hemolytic complement, were found by comparison with healthy individuals to have significantly increased levels of circulating immune complexes. The identity of the immune complexes was established by sucrose density gradient ultracentrifugation, which showed them to sediment between 10 and 19S. As they were adsorbable by rheumatoid factor--Sepharose 4B conjugates, it appeared that these complexes were composed of IgG. The complexes were retained by Concanavalin A--Sepharose columns and eluted by alpha methyl-D-mannoside, suggesting by analogy with model complexes that the antigens might be glycoproteins.

Topics: Adsorption; Antibodies, Heterophile; Antigen-Antibody Complex; Antigens, Heterophile; Burkitt Lymphoma; Cell Line; Centrifugation, Density Gradient; Chromatography, Affinity; Complement C3; Complement System Proteins; Concanavalin A; Hemolytic Plaque Technique; Humans; Immunoglobulin G; Male; Nasopharyngeal Neoplasms; Rheumatoid Factor; Sepharose