Cell receptor studies on seven cases of diffuse histiocytic malignant lymphoma (reticulum cell sarcoma).
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Expression of B and T lymphocyte receptors has been studied in seven cases of reticulum cell sarcoma. In one case, surface receptors and tests of phagocytic function demonstrated the histiocytic origin of the neoplastic cells. In four cases, tumour cells expressed both B and T lymphocyte markers (two cases) or showed a normal pattern of expression of B and T lymphocyte markers. In the other two cases, lymphocyte receptors were not detected, and there was no evidence of phagocytic function: this class of receptor-silent tumours is of uncertain pathogenesis. The significance of these observations is discussed. (+info)
Effects on C-reactive protein on the lymphoid system. I. Binding to thymus-dependent lymphocytes and alteration of their functions.
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C-reactive protein (CRP) is an acute phase protein which shares with the immunoglobulins the ability to induce precipitation and agglutination reactions and activate the complement system. We report here that purified human CRP binds selectively to human T lymphocytes, inhibits their ability to form spontaneous rosettes with sheep erythrocytes and inhibits their response to allogeneic cells in mixed lymphocyte culture reactions; it fails to inhibit phytohemagglutinin- or concanavalin-A-induced mitogenesis. CRP does not bind to human B lymphocytes, nor does it alter the following B-cell functions: binding to activated complement components or the Fc portion of immunoglobulins, mediation of antibody-dependent cytotoxicity reactions or the ability of allogeneic cells to stimulate a mixed lymphocyte culture reaction. Human CRP shows similar selective binding with murine T lymphocytes. It therefore seems that binding of CRP is a property of T lymphocytes or a subpopulation thereof, and can result in modulation of certain of the T-cell functional characteristics in vitro. We suggest that CRP may play a role in modulating T-cell functions during the inflammatory state. (+info)
Proliferation and colony-forming ability of peritoneal exudate cells in liquid culture.
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Peritoneal exudate cells, obtained from mice injected with thioglycollate medium and cultured in medium containing L-cell-conditioned medium, will proliferate in an exponential fashion for 18 days with a doubling time of 68 h. After a 2 h pulse of tritiated thymidine, labeled adherent cells increased to a maximum of 22-34% during the 1st and 2nd wk of culture. Increasing the cell concentration from 2 times 10-3 to 2 times 10-5 cells/culture reduced exponential growth to 10 days and the doubling time was increased to 81.6 h. Under these culture conditions, peritoneal exudate cells were shown to form colonies on the surface of culture dishes when plated at low density. The cells within the colony were shown to be macrophages using yeast and antibody-coated sheep erythrocytes as a test for phagocytic function. The plating efficiolonies arose from a single precursor cell. The adherent cell population contains the colony-forming precursors. These precursors can be stimulated to form colonies for at least 2 wk by the addition of conditioned medium to cultures at various times after plating. While very few colony-forming cells could be demonstrated in the unstimulated peritoneal lavage, their numbers begin to increase in the exudate 4 h after injection of thioglycollate medium and reach a maximum by day 3 and then decrease. Isolated colonies may be useful in studying the function of macrophages. (+info)
A comparison of the acute effects of radiation therapy, including or excluding the thymus, on the lymphocyte subpopulations of cancer patients.
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Radiation therapy to either mediastinum or pelvis causes a rapid decrease in circulating lymphocytes of both B and T types and in addition an impairment in the function of the remaining lyphocytes, as measured by their ability to proliferate in response to mitogens. The acute depression is short-lived. Substantial recovery is apparent within 3 wk after cessation of therapy; however, most patients show a modest, chronic depression in both numbers and functional capacities of circulating lymphocytes. T cells are somewhat more sensitive than B cells, but both are affected. Irradiation of the thymus per se seems to have little influence on the acute changes which occur, as patients receiving pelvic and mediastinal (including thymic) radiotherapy show a similiar degree of lymphopenia and depression of lymphocyte responsiveness. (+info)
Complement receptor lymphocytes. Analysis of immunoglobin on their surface and further evidence of heterogeneity.
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Mouse complement receptor lymphocytes (CRL) were detected by a rosetting method. The existence of an immunoglobulin class or subclass on the central rosetting cell wasstudied by immunofluorescence using rabbit antisera specific for mouse IgM, IgG1, IgG2a, IgG2b and IgA. Combining immunofluorescence for each immunoglobulin and for T cells with cytoxic removal of T cells, CRL were demonstrated to include immunoglobulin-bearing cells of all the classes and subclasses tested (IgM being the main one), a 'null' cell subpopulation, and some T cells. A scheme describingthe various nature of CRL is discussed and correlated with possible functions. (+info)
Studies on B- and T-cell receptors for lysozyme.
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BALB/c mice have been immunized by intravenous administration of native or reduced and alkylated lysozyme. Primary immune response to these antigens was studied at the humoral level (by the Farr assay) and at the cellular level (by the rosette and the plaque assays using lysozyme coupled to sheep or pigeon erythrocytes). Antibodies and theta-negative RFC were specific for the antigen used for immunization. Specific inhibition of theta-negative RFC after incubation with the soluble immunizing antigen confirmed this specificity. Conversely, most theta-positive RFC had double specificity both to native and denatured lysozyme and showed lower avidity for the immunizing antigen, as shown by inhibition studies with soluble antigen. These data suggest that T cells have a broader specificity for lysozyme than B cells and also that, in this particular system, cytophilic antibodies are probably not responsible for the formation of theta-positive rosettes. (+info)
Influence of adrenaline on the dissemination of antibody-producing cells from the spleen.
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Plaque-forming cells (PFC) and rosette-forming cells (RFC) were quantificated in splenic venous and splenic arterial blood and in spleen suspensions of guinea-pigs during a secondary immune response to sheep red blood cells (SRBC). The splenic veno-arterial differences in content of PFC and RFC were determined, indicating whether there had been a release of such cells from the spleen into the blood. The effect of an intracardial injection of adrenaline on the release of immune lymphocytes was investigated. In immunized control animals a splenic release of antigen-binding and antibody-forming cells was found, the release being restricted to the peak of the immune response in the spleen. However, after exogenous adrenaline a considerably increased release of both antigen-binding and antibody-forming cells occurred during a longer period of the immune response. Thus, adrenaline caused an enormous release of PFC from the spleen into the blood on day 4 of the secondary immune response, resulting in a diminished number of PFC remaining in the spleen after the treatment. A physiological significance of an adrenaline-induced dissemination of immune lymphocytes in the body during an immune response to a severe infectious disease is suggested. (+info)
Surface markers on lymphocytes of multiple sclerosis patients.
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Peripheral blood lymphocytes of twenty-two multiple sclerosis (MS) patients and thirty-five healthy controls were examined for the presence of surface markers characteristic for B lymphocytes (surface immunoglobulin, receptor for C3 (EAC), reporter for Fc (EA) and the spontaneous rosette-forming capacity characteristic of T cells. The results obtained indicate that the number of B and T cells in MS is similar to controls, as evaluated by the presence of surface immunoglobulin and E rosette-forming capacity. However, a statistically significant reduction in the percentage of lymphocytes bearing C3 receptors has been found in MS patients. It might have resulted from a reduction in the lymphocyte population bearing C3 receptor but no surface immunoglobulin. The EA rosette test revealed the greatest difference between the groups. The difference indicated a reduction in the density of the receptor for 7S Fc on lymphocytes from MS patients. The results obtained are consistent with the hypothesis of an immune deficit in multiple sclerosis. (+info)