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Query: UMLS:C1275122 (TEM)
 21,810 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sheep erythrocytes (E) which, with or without certain treatments, are currently used as "immunological reagents" to detect cells with specific receptors (by rosette-formation) have been partitioned in two-polymer aqueous-phase systems selected so as to reflect charge-associated or lipid-related membrane surface properties. We have found that the partitioning behavior of E is not affected in these phases by reacting the cells with anti-E antibody (either IgG or IgM), forming EA. The additional binding of complement to the cell-antibody complex, forming EAC, results, however, in a marked decrease in the partition coefficient, K. Apparently both the charge-associated and hydrophobic properties reflected by partitioning remain accessible to the phase polymers when the cells are coated with antibody, but are not with the addition of complement. It is interesting that EA can still rosette with T-lymphocytes (14), a property of E, while the additional coating with complement results in EAC which does not appreciably do so (26). Neuraminidase or trypsin treatments of E, which yield Es having quite different rosetting properties with T-lymphocytes (14), cause increased Ks and unchanged Ks, respectively, in phases reflecting lipid-related surface properties. Either treatment causes reduced Ks of E in charged-phase systems. Neuraminidase treatment also results in a reduced electrophoretic mobility of E, while trypsin treatment is not detectable by cell electrophoresis (25). We are currently studying the possible usefulness of employing cell electrophoresis and cell partitioning in charged-phase systems jointly to obtain information on events occurring at the shear plane versus those occurring deeper in the membrane.
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PMID:Membrane surface properties of sheep erythrocytes, an immunological reagent, after different treatments as reflected by partition in two-polymer aqueous phases. 9 74

Five lots (100 ml or more) of heterologous antiserums specific for human T lymphocytes were prepared using human or Rhesus monkey thymocytes as immunogens. After appropriate adsorptions, these antiserums reacted by immunofluorescence with 68% of human peripheral blood mononuclear cells and 98% of human thymocytes, with E-rosette--positive cells but not with EAC-rosette--positive cells or five human B-lymphoblastoid-cell lines. Blocking experiments showed that Rhesus monkey thymocytes share thymic antigenic determinant(s) with humans. E-rosette receptors modulated independently from T-cell heteroantigens. Non-E--rosetting neoplastic T cells were identified in several patients with lymphoproliferative malignancies. Applying both the E-rosette assay and the anti-T-cell serum provides a better method of defining the biologic properties of normal and neoplastic T lymphocytes. Standardization of immunofluorescent conjugates for human T- or B-cell enumeration is simplified if large lots of well-characterized antiserums are available.
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PMID:Antiserums for immunofluorescent enumeration of human T lymphocytes utilizing fluoresceinated staphylococcal protein A. 9 47

Over 70% of rhesus monkey peripheral mononuclear cells were isolated on sodium metrizoate-ficoll gradients with greater than 98% purity. Rhesus blood contained 47.8% active E, 58.2% total E, and 30.2% EAC rosette forming cells. Optimal conditions for mitogen studies were determined using phytohemagglutinin, concanavalin A, pokeweed mitogen, lipopolysaccharide and streptolysin O.
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PMID:Lymphocyte isolation, rosette formation, and mitogen stimulation in Rhesus monkeys. 9 37

We have shown that the first component of complement C1 is present in an active form on the surface of washed human peripheral lymphocytes but not on platelets or erythrocytes. This active C1 (C-1) was detected by its ability to transfer to sensitized cells carrying C4, i.e., EAC4, forming EAC-1,4. Active C1 was also able to consume C4. Treatment of these lymphocytes with 0.02 M EDTA removed C-1. EDTA-treated lymphocytes were able to bind exogenous purified human C-1. Comparative studies with sentized erythrocytes (EA) and EDTA treated lymphocytes showed that although fewer molecules of exogenous C1 could bind to the EDTA-treated lymphocytes than to EA, the consumption of C4 by C-1 bound to lymphocytes was significantly higher than that observed with EAC-1. When lymphocytes obtained from 2 patients with chronic lymphocytic leukemia and hypocomplementemia were tested, the release of C1, the C4 consumption and the binding of C-1 to EDTA-treated cells were highly inefficient.
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PMID:The presence of active C1 (C-1) on peripheral human lymphocytes. 9 72

We have found that, although the binding of particulate antigen-antibody complement complexes such as EAC to lymphoblastoid Raji cells is mediated largely through receptors for C3b, the binding of complement-containing soluble complexes such as those prepared with aggregated human IgG (AHG) occurs also via receptors for C1q. Evidence supporting this conclusion included: (1) Binding of AHG to Raji cells takes place after incubation in EDTA serum; (2) Binding of AHG does not occur in C1q deficient EDTA serum but does take place after addition of C1q; (3) The extent of binding of AHG in EDTA serum is a function of the amount of C1q present; (4) Raji cells can bind up to 5-4 times 10(5) molecules of 125I C1q per cell which can be blocked by unlabelled C1q; (5) AHG pre-incubated with C can bind to a T-cell line MOLT, which lacks receptors for C3b but possesses receptors for C1q to the same extent as Raji cells; (6) Immunoassays for immune complexes in human sera yield similar results whether Raji cells, MOLT cells or C1q precipitation is used for assay; (7) EAC-Raji cell rosettes can be inhibited with inulin-treated, C1q deficient serum containing C3b or C3d whereas binding of AHG or immune complexes in patient samples to Raji or MOLT cells is not inhibited by this reagent. We conclude that receptors for C1q on certain B and T lymphocytes may play an important role in physiologic functions of lymphocytes depending on binding of soluble immune complexes to their surfaces.
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PMID:Binding of soluble immune complexes to Raji lymphocytes. Role of receptors for complement components, C1q and C3-C3b. 10 87

The survival time of skin allografts from RhLA-nonidentical, unrelated donors was increased from a mean of 7.69 days in controls (n = 20) to a mean of 32.53 days in rhesus monkeys (n = 21) receiving a total dose of 250 mg of rabbit anti-human thymocyte globulin (RATG) per kg. Immunological monitoring studies were performed on the peripheral blood of mononuclear cells in control and treated monkeys. After administration of RATG, the percentage of E rosette-forming cells (E-RFC) was greater than 90% depressed, and the percentage of EAC rosette-forming cells was increased 5-fold in the circulation. Significant numbers of RATG-coated cells were detected only during the first week after RATG treatment. The percentage of E-RFC recovered to pretreatment levels within 3 to 4 weeks after RATG treatment, although the absolute E-RFC count remained depressed for 2 to 3 months. In addition, the in vitro proliferative responsiveness to polyclonal mitogens and to allogeneic lymphocytes remained greater than 80% depressed for 2 to 3 months after RATG treatment. The incidence of post-transplant-specific antidonor lymphocyte-mediated cytotoxicity (LMC) was similar in controls (85%) and RATG-treated monkeys (81%), and the appearance of LMC was correlated (r = 0.711) with partial recovery of absolute ERFC counts in the treated group. The appearance and peak of LMC were delayed (P less than 0.001) in RATG-treated monkeys, but preceded and correlated with rejection. Prior to rejection, the serum of RATG-treated monkeys inhibited LMC. Antibody-dependent cellular cytotoxicity appeared after rejection in the majority of recipients in both groups. The appearance and peak of antibody-dependent cell-mediated cytotoxicity (ADCC) were delayed (P less than than 0.001) in RATG-treated monkeys, but did not exhibit a significant correlation with the time of rejection.
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PMID:Effect of rabbit anti-human thymocyte globulin on lymphocyte subpopulations and functions following allotransplantation in the rhesus monkey. 10 31

Periodic control examinations of Rh-negative blood donors sensitized with human Rh-positive erythrocytes were performed to establish the differences in the levels of T and B lymphocytes and their correlation with the production of anti-Rh D antibodies. The investigations were carried out on 10 healthy blood donors in the initial period of immunization and 8 blood donors who had received multiple injections of these erythrocytes and who were producing anti-Rh antibodies. The control group included 10 non-immunized blood donors. The percentage of T and B lymphocytes was calculated on the basis of the rosette tests (E, EA, EAC) while the level of antibodies produced in serum was determined by serological methods. During immunization of blood donors no significant differences were observed in the level of T lymphocytes, while the level of B lymphocytes increased, especially in the 3rd week after the 1st or 2nd injection of erythrocytes and this was not correlated with the production of anti-Rh D antibodies in later period.
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PMID:Trials of rosette test application for determination of immune response to antigen D from the Rh system in blood donors immunized with human erythrocytes. 10 11

T-, B- and Fc-gamma-receptor-bearing lymphocytes were detected using six different membrane markers in patients suffering from asthma having either normal or low serum IgA levels. E rosettes, aE rosettes and a human anti-T lymphocyte antiserum (HTLA) were used for T cell determination. In patients with low serum IgA levels E rosettes were significantly decreased. B lymphocytes were identified by EAC rosette formation and visualization of surface membrane immunoglobulins (SmIg). No significant difference was seen. Fc-gamma-receptor-bearing lymphocytes were assessed by the EA rosette assay and were significantly decreased in asthmatics with normal IgA levels. This result might be explained by the presence of immune complexes.
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PMID:T-, B- and Fc-gamma-receptor-bearing lymphocytes in asthma. 11 74

Subpopulations of human peripheral blood leukocytes were isolated by rosette formation and tested for functional activity. E -rosette-forming cells (E-RFC) and EAC-RFC were separated from non-resetting cells by sedimentation on Ficoll-Hypaque gradients. The efficiency of the method and the purity of the resulting subpopulations were high. E-RFC responded to PHA Con A, allogeneic leukocytes, and PPD, with higher levels of proliferative reactivity than the unseparated lymphocytes while E-RFC depleted, EAC-RFC, and null cells showed only low levels of reactivity. Reactivity to PWM and tetanus toxoid was also restricted to the E-RFC subpopulation, but was lower than that of unseparated cells. A staphylococcal antigen preparation triggered lymphoproliferative reactivity in the E-RFC, E-RFC depleted, EAC-RFC, and the null cell subpopulations. 51Cr release lymphocyte cytotoxicity against a human lymphoblast target cell line was found in the E-RFC and null cell fractions but was not observed with the EAC-RFC subpopulation.
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PMID:Functional activities of rosette separated human peripheral blood leukocytes. 12 61

Mononuclear cells (10--20 X 10(6)) obtained from human peripheral blood by a standard Ficoll-Hypaque technique were suspended in RPMI 1640 media at 4 degrees C containing 10% foetal calf serum and 7-5% dimethyl sulphoxide (DMSO). Two-millilitre aliquots were cooled at -1 degree C/min in a Cryoson BV-4 programmed freezing system to -30 degrees C, then -5 degrees C/min to -80 degrees C and stored in liquid nitrogen vapor. On the day of testing, cell suspensions were thawed rapidly in a 37 degree C water bath. DMSO was diluted slowly out of the sample and cells resuspended in fresh RPMI 1640. It was found that frozen stored human lymphocytes (FSHL) demonstrated all the characteristics of fresh unfrozen cells. These included their ability to form spontaneous rosettes with sheep erythrocytes ('E' rosettes) and sheep erythrocyte--antibody--complement rosettes ('EAC' rosettes). The presence of surface immunoglobulins and Fc receptors were shown by membrane immunofluorescence to be comparable. In addition, the results show that FSHL respond to mitogens, specific antigens; act as both stimulators and responders in the mixed lymphocyte culture reaction; and exhibit cell-mediated lymphocytotoxicity following in vitro sensitization, or against antibody-coated target cells.
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PMID:Immunological responsiveness of frozen-thawed human lymphocytes. 12 29


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