Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Specific cell-mediated immunity to SV40 tumor-specific transplantation antigen (TSTA) in BALB/c mice undergoing progressive tumorigenesis by syngeneic SV40-transformed cells (VLM) was investigated in vivo using a tumor-cell neutralization test. Specific cellular reactivity to SV40 TSTA was not detected in BALB/c mice bearing large tumors (10-15 mm mean diameter) but was demonstrable after tumor excision. Specific cytotoxic reactivity against syngeneic SV40-transformed cells in vivo could be restored to lymphoid cells from VLM tumor-bearing mice either by culturing the lymphoid cells in vitro or by treating them with papain or trypsin. Enzyme-treated lymphoid cells from MCA tumor-bearing BALB/c mice had no cytotoxic reactivity against VLM cells. These studies suggest that tumor-bearing hosts possess lymphocytes which are sensitized to the TSTA of the tumor but that the reactivity of these lymphocytes is blocked.
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PMID:Restoration of specific immunity against SV40 tumor-specific transplantation antigen to lymphoid cells from tumor-bearing mice. 5 Oct 12

Nonadherent and nonphagocytic lymphoid cells from human peripheral blood became strongly cytotoxic against 51Cr-labeled chicken red blood cells and cells from an established human myeloma cell line when subjected to repeated cycles of washing in phosphate buffered saline or treated with trypsin or lecithinase. Prior to augmentation the effector cells pass nylon wool columns that remove practically all surface IgG-positive cells, but after augmentation they are retained in such columns. Augmentation does not make them phagocytic or adherent to plastic surfaces. Incubation at 37 degrees C of augmented cells prior to addition on the target cells restores the original nonaggressive state. Morphologically the cells making contact with the target cells are small or intermediate-sized mononuclear cells.
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PMID:Spontaneous, augmentable cell-mediated cytotoxicity with limited target cell specificity in human blood. 6 51

Mice lose demonstrable delayed hypersensitivity (DH) to DNFB, picryl chloride, or sheep red blood cells. Reconstitution of immune responsiveness can be accomplished by administration of cell-free lysates of spleens from mice with active DH to structurally related, but not to unrelated antigens. Peritoneal exudate cell lysates from mice with active DNFB-DH also restore DH to this antigen. Sera from sensitized mice, and sera and lymphoid tissue extracts from unsensitized mice are without activity. The restorative property of splenic lysates from DNFB-sensitized mice is unstable at 56 degrees C, not sedimented at 90,000 X G and inactivated by trypsin or magnesium ions. The presence of unexpressed, restorable DH may provide a biologic basis for the so called "transfer factor" phenomenon.
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PMID:Specific restoration of delayed hypersensitivity by lymphoid tissue extracts. 6 74

To investigate the antigenic relationship between the macrophage and lymphocyte Fc receptors (FcR), a monoclonal antibody capable of blocking mouse macrophage Fc receptors was selected. Hybrids were formed by fusing the P3U1 mouse myeloma and spleen cells from a rat immunized with the mouse macrophage-like cell lines J774 and P388D1. The Fab fragment of the monoclonal IgG secreted by clone 2.4G2, inhibited the trypsin-resistant Fc receptor II (FcRII), which is specific for immune aggregates of mouse IgG1 and IgG2b, but had no inhibitory effect on the trypsin-sensitive Fc receptor I (FcRI), which binds monomeric IgG2a and erythrocytes coated with IgG2a. Thus, the monoclonal 2.4G2 IgG appeared to be specific for macrophage FcRII. Further evidence that the 2.4G2 IgG was directed against FcRII came from binding studies of the monoclonal antibody to J774 cells and a series of independently isolated variants which do not express FcRII. These variants of J774 bound 5% as much of the monoclonal antibody as the parent line, which bound 600,000 molecules of 2.4G2 IgG per cell. The antigenic relatedness of mouse lymphocyte FcR to mouse macrophage FcRII was demonstrated by the binding of 2.4G2 IgG to FcR-bearing lymphoid cell lines and the inhibition of the lymphocyte FcR by the monoclonal antibody. Preincubation of spleen cells and peritioneal cells with 2.3G2 IgG likewise inhibited rosette formation with ox erythrocytes coated with rabbit IgG. The ability of the hybridoma IgG to inhibit mouse FcRII was independent of the major histocompatibility complex. The 2.4G2 IgG antigenic determinant was not present on rat, guinea pig, rabbit, or human FcR-bearing cells.
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PMID:Characterization of a monoclonal antibody directed against mouse macrophage and lymphocyte Fc receptors. 9 Jan 8

The present paper describes a study on rosette formation by human lymphoid cells with monkey erythrocytes (MRBC) obtained from two species: African green monkey (Cercopithecus aethiops) and rhesus monkey (Macaca mulata). All the lymphocyte preparations obtained from peripheral blood, tonsils, thymocytes, bone-marrow and spleen biopsies formed rosettes in variable proportions with erythrocytes obtained from these two monkey species tested. Cells of established lymphoblastoid cell lines characterized as being of either B- or T-cell origin also formed rosettes with MRBC. Taken together, the data obtained suggest that the MRBC-rosette assay cannot be reliably used for identifying lymphocyte subpopulations presently known to us, thus largely contradicting the observations previously reported by others on the use of this assay. In addition, we found that the binding sites for MRBC on the above lymphoid cells are highly sensitive to trypsin treatment and can fully be regenerated within 14-15 h when these treated cells are cultured at 37 degrees.
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PMID:Rosette formation by human lymphoid cells with monkey red blood cells. 10 44

Ribonucleic acid extracts of lymphoid cells from immune hosts were used to transfer in vivo and in vitro cell-mediated immune reactivity to a variety of antigens. The in vivo immune responses transferred by RNA included the delayed cutaneous hypersensitivity reaction to fungal and chemically-defined antigens and the tumor-rejection reaction to guinea pig hepatoma antigens. The in vitro immune responses transferred by RNA included macrophage migration inhibition by fungal, chemically-defined, and tumor antigens. The transfer activity of RNA preparations was contained in the 8 s to 18 s species of RNA and was sensitive to RNase but not to DNase or trypsin. Antigen was not detectable in the RNA preparations and appeared to have no role in the transfer activity. Syngeneic, allogeneic, or xenogeneic sources of RNA could transfer immune reactivity. In each system tested, the transfer of cell-mediated reactivity by RNA was specific for the antigen used to sensitize the RNA donor. The potential use of RNA-mediated transfer of immunity is discussed.
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PMID:Some perspectives on the transfer of cell-mediated immunity by immune-RNA. 11 79

The preparation of highly purified granulocytic chalone from bone marrow conditioned medium is described. A sequence of gel-chromatographic steps on Sephadex G-25, G-15 and Biogel P-6 is applied. The end product has a sigmoid dose-response-curve with a plateau at 40-50% inhibition of thymidine incorporation. The inhibition is only observed with bone marrow cells as target cells whereas lymphoid cells are not affected. When bone marrow cells are treated for 1 min with 0.005% trypsin and subsequently used for assaying chalone activity in the presence of cycloheximide, no inhibition is found. These results may indicate that chalone specific receptor sites (of protein nature) are present on the surface of the target cells, which are destroyed by the trypsin treatment. Granulocytic chalone is soluble in aqueous solvents and in polar organic solvent mixtures. Its activity is destroyed by trypsin but only after prolonged treatment. The elution behaviour of chalone is discussed in detail. Chromatography on Sephadex G-75 and Ultrafiltration point to a molecular weight of several thousands, whereas chromatography on G-25 or G-15 or on Biogel P-6 would indicate a rather low molecular weight.
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PMID:Separation, identification and mechanism of action of the granulocytic chalone. 13 Jan 42

A Herpesvirus saimiri-infected marmoset lymphoid cell line (MLC-1) was examined for the presence of soluble factors which might affect lymphocyte functions and, therefore, relate to the pathogenesis of lymphoma in vivo. MLC-1 cells, cell extracts, and culture fluids were shown to reduce the spontaneous deoxyribonucleic acid (DNA) synthesis of normal peripheral blood lymphocytes and to completely inhibit their response to phytohemagglutinin (PHA). Suppression of PHA response was demonstrated against a variety of human and nonhuman primate species, with 90 to 95% inhibition occurring at dilutions of extract as great as 1:5,120. Inhibition of this type was also demonstrated using extracts of two of five other lymphoblastoid cell lines tested. Physical-chemical characteristics of the active factor(s) revealed a non-sedimentable, non-dialyzable, trypsin-resistant molecule, which was stable at 56 C for 30 min but inactivated at 80 C for 30 min. The factor(s) also exerted an effect on some but not all established lymphoblastoid cell lines, where DNA, ribonucleic acid, and protein synthesis were all inhibited, with DNA synthesis being the most affected (95% suppression). Cellular respiration was not affected by the presence of the factor(s), and the inhibition of DNA synthesis was reversible after 24 h. Purified human interferon did not reduce the PHA response of normal owl monkey peripheral blood lymphocytes and was less effective against an established lymphoblastoid cell line than the MLC-1 extract. Antiviral activity was also demonstrated in the preparations and may represent interferon, which these cells are known to produce at low levels.
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PMID:Inhibition of the mitogenic response of normal peripheral lymphocytes by extracts or supernatant fluids of a Herpesvirus saimiri lymphoid tumor cell line. 17 49

To evaluate subclass specificity and aggregate size requirements of IgG receptors on mouse cells, we measured binding of radiolabeled monomeric and BDB-aggregated mouse myeloma proteins fractionated into various sizes by means of gel filtration. Monomers, tetramers, and high molecular weight (approximately 10(7) daltons) aggregates were used. The various cells and cell lines studied could be segregated into three patterns of reactivity: (a) Macrophage and macrophage-like cell lines bound monomer IgG2a preferentially; high molecular weight IgG aggregates bound as follows: IgG1 = IgG2b = IgG2a. (b) Lymphoid lines D2N and S49 showed no capacity to bind monomer IgG2a; high molecular weight aggregates bound as follows: IgG1 = IgG2b less than IgG2a. (c) Other Thy-1-positive lymphoid cell lines (EL4 and L5178) and normal T and B cells showed no capacity to bind monomer IgG; high molecular weight IgG aggregates bound to a lesser extent than to cells of the first two categories in the following manner: IgG1 less than IgG2b greater than or equal to IgG2a. The variable pattern of reactivity of the macrophage-like cell lines with monomer and aggregated IgG suggested that two distinct receptors for IgG were present: one capable of binding IgG2a and another capable of binding all aggregates. Further evidence for this hypothesis was obtained by analysis of the inhibitory capacity of different IgG subclasses on the binding of aggregated IgG and monomer IgG2a to P388 cells. Inhibition of monomer IgG2a binding was effected only by monomer or aggregated IgG2a, whereas inhibition of binding of aggregated IgG1 or IgG2b was noted with aggregates of all three subclasses with some preferential inhibition by monomer IgG2b being observed. Furthermore, monomer IgG2b binding was preferentially inhibitable by monomer IgG2b. It is postulated from these data that two receptor sites are present on this macrophage-like cell line, one reactive with aggregates of all three subclasses as well as monomer IgG2b, and another receptor specific for monomer IgG2a which also binds aggregated IgG2a. Support of this concept was obtained by trypsinization experiments in which the binding of monomer IgG2a was markedly decreased by trypsin treatment of cells, whereas the binding of aggregated IgG2b was unaffected by this treatment.
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PMID:Receptors for IgG: subclass specificity of receptors on different mouse cell types and the definition of two distinct receptors on a macrophage cell line. 30 Jul 83

Regional (popliteal) lymph node cells (RLNC) from A/Jax mice, inoculated in each hind foot with isogeneic Sarcoma 1 tumor cells, demonstrated cytotoxicity in vitro at Day 14 of tumor growth but lost this ability by Day 21. These noncytotoxic RLNC were capable of suppressing activity of other cytotoxic lymphoid cells, but after incubation for 24 hr in vitro their cytotoxicity was restored and their suppressive activity was abrogated. RLNC responsible for cytotoxicity were removed by treatment with anti-theta serum plus complement. The suppressive effect of RLNC was found to be mediated by a soluble "blocking" factor which was released into the culture medium after 24 hr incubation. The factor was not detected in culture media from RLNC pretreated with anti-theta serum plus complement prior to incubation. Absorption of RLNC culture supernatants with tumor-bearer spleen cells, but not with normal spleen cells, completely removed the blocking factor, while absorption by Sarcoma 1 cells significantly reduced blocking activity. The factor was trypsin sensitive, was retained on an Amicon XM100 filter, and did not demonstrate the presence of antibody to Sarcoma 1 in a radioimmunoassay. Although the exact nature of the factor has not been established, it appears to be a receptor antigen complex from T-cells of tumor-bearing animals.
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PMID:Immunological activity of regional lymph nodes in tumor-bearing mice. 31 91


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