Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.10.1 (ERK)
95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Purified interleukins 1 and 2 (IL-1 and IL-2) were used to investigate their role in the production of gamma-interferon (gamma-IFN). Macrophage depletion from human peripheral blood mononuclear leukocytes (PBML) inhibited gamma-IFN production. Addition of purified IL-1 partially restored IFN production of macrophage-depleted PBML induced by three T cell mitogens (phytohemagglutinin, PHA; concanavalin A, con A; and staphylococcal enterotoxin A, SEA), but had no effect on induction of IFN production by undepleted PBML. Therefore endogenous IL-1 production by macrophages is probably one of the mechanisms by which they act as accessory cells for IFN production by lymphocytes. A monoclonal antibody 9.6 which binds to the sheep erythrocyte (E) receptor found on human T cells inhibited IFN production. Addition of IL-2, but not IL-1, was found to reverse this inhibition. Prostaglandin E2, a macrophage product, inhibited gamma-IFN production induced by PHA, Con A, and OKT3 but usually not SEA. This inhibitory effect was reversible by the addition of IL-2 but not IL-1. In the absence of mitogen IL-1 alone rarely induced any IFN production, although some IFN was produced by PBML from a small minority of donors. Without mitogen IL-2 induced IFN production only at very high concentrations and the added presence of IL-1 did not enhance this induction.
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PMID:The regulation of gamma-interferon production by interleukins 1 and 2. 310 55

Seventeen Thy-1+ cell clones were induced in A/J mice immunized with the HEP-Flury strain of rabies virus after repeated stimulations with antigens in vitro. Ten clones with cell surface phenotypes Thy-1+, Lyt-1-,2+ were cytotoxic T lymphocytes (CTL) which lysed the virus-infected target cells under H-2 restriction. Target cells expressed the G and M2 structural proteins of rabies virus on their surface; however, target lysis by CTL clones was not blocked by anti-rabies antibody or by monoclonal antibodies to these proteins. All of the CTL clones efficiently and equally lysed target cells infected with three different strains of rabies virus and were cross-reactive for target cells infected with one (Duvenhage virus) of three different rabies serogroup viruses. Another five clones having phenotype Thy-1+, Lyt-1+,2- did not show any cytotoxic activity. The proliferation response of these clones to antigen stimulation was virus-specific and H-2-restricted. These clones were able to grow in culture medium without any or with the addition of low concentrations of T cell growth factor, in contrast to CTL clones, and were considered to be helper T lymphocytes (HTL). Both CTL and HTL clones produced gamma-interferon in response to antigen stimulation. The remaining two clones were Thy-1+, Lyt-1-,2-, asialo-GM1+, and were not cytotoxic to target cells even in the presence of anti-rabies antibody but were cytotoxic to YAC-1 cells. Further studies with these clones should allow us to investigate more closely the role of T cells in the pathogenesis of rabies.
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PMID:Murine T cell clones directed to rabies virus: isolation and some of their properties. 310 64

Effects of human recombinant-DNA derived interferon-gamma and -alpha 2 on the adhesion of cultured breast cancer cells (BT-20, ZR-75.1, MCF-7, 734-B and Hs-578-T), larynx carcinoma cells (HEP-2), epidermoid carcinoma cells (KB), lung carcinoma cells (CCL 185), and ovarian carcinoma cells (1847) to the surface of cell culture plastic dishes were studied. Layered cells were detached after a 3-day treatment with interferon either by trypsin-EDTA, trypsin, protease or cooling to 4 degrees C. Treatment with interferon-gamma (500 unit/ml) significantly increased the incubation time for trypsin-EDTA, EDTA and at 4 degrees C necessary to bring cells into suspension for the 4 cell lines BT-20, ZR-75.1, MCF-7 and HEP-2. Interferon-alpha 2 was not able to induce a similar effect. Reattachment of interferon-gamma treated ZR-75.1 cells was not increased after harvesting by trypsinization or EDTA action. Decreased adhesion of cultured cells is associated with transformation and the effects of interferon-gamma may be explained by reinforced normal phenotype. Interferon-gamma induced adhesion was not associated with other interferon effects especially the anti-proliferative activity or modulation of surface antigens.
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PMID:Human interferon-gamma increases adhesion of cultured carcinoma cells to the substratum. 311 53

We examined whether a combined use of UFT with interferon against human KDR-1 strain cells was effective or not. KDR-1 strain derived from the patient with renal cell carcinoma was transplanted into nude mice. When the tumor grew large enough, the mice were divided into 4 groups. The group consisted of 1) oral use of 5% Acasia as a control, 2) oral administration of UFT, 3) combined use of UFT and IFN-alpha, 4) intraperitoneal injection of IFN. Each group was treated continuously for 16 days. Antitumor effect was not observed in group 2 and 4, but observed in group 3. The concentration of UFT in the tumor tissue did not show any differences between combination and UFT groups. Therefore, there is no evidence to prove that IFN-alpha makes UFT level higher. Antitumor effect was observed histopathologically in the combined regimen group, although a mechanism of synergistic effect is still unknown.
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PMID:[Antitumor activity of UFT and interferon-alpha against human renal cell carcinoma in athymic nude mice]. 312 84

A range of monosaccharides was tested for its ability to inhibit the generation of cytotoxic cells during mixed lymphocyte culture. The most discriminatory effect was produced by N-acetyl-D-galactosamine (NADG). The presence of this sugar at the initiation of the coculture significantly inhibited in a dose-dependent manner the induction of a subset of nonspecific activated lymphocyte (ALK) cells preferentially able to lyse the K562 target cell (natural killer, NK-like cells) but had no effect on the generation of either specific cytotoxic T lymphocytes or another separate subset of ALK cells mediating lysis of an NK-insensitive melanoma cell line. The addition of conditioned medium containing interleukin 2 and interferon (IFN) at the start of culture reversed the inhibitory effect of the sugar. Under conditions of limiting dilution, the frequency of NK-like precursors ranged from 1/50 to 1/1200 with different mononuclear cells (MNC) and in all cases the presence of NADG from Day 0 of culture selectively decreased the frequency of these precursors. At the concentrations used NADG had no effect on NK-like cell cytolysis once generated. The addition of recombinant gamma-IFN did not abrogate the inhibitory effect of NADG and in MLC of some individuals decreased the frequencies of ALK cell precursors. These data provide further evidence for the heterogeneity of ALK cells and indicate that what is usually referred to as NK-like cell activity in in vitro culture is mediated by a subpopulation of MNC which are activated and induced to differentiate along a pathway independent of that of other ALK subsets.
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PMID:In vitro generation of human activated lymphocyte killer cells. II. N-acetyl-D-galactosamine inhibits a distinct subpopulation of human activated lymphocyte killer cells generated in mixed lymphocyte culture. 315 1

Direct correlation was established between changes in the activity of natural killers and capacity of lymphocytes for interferon synthesis after stress was demonstrated. Thymosin was found to enhance interferon synthesis in response to induction with NDV, PHA, and SEA in the period of marked inhibition of splenocyte function as a result of stress. The phenomenon of restoration by thymosin of the capacity of splenocytes in the post-stress phase to synthesize interferon in response to induction was also established in vivo.
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PMID:[Thymosin restoration of the interferon-synthesizing capacity of the splenocytes in mice undergoing stress exposure]. 387 11

Apparent interferon-mediated persistent infection of rabies virus (HEP-Flury strain) was established in a human neuroblastoma SYM-I (clone K-104) cell line, which had the ability to produce interferon. This infection produced variable but small amounts of progeny virus and interferon (up to 100 IU/ml), and resisted superinfection with vesicular stomatitis virus (VSV) and Sindbis virus as well as homologous rabies virus. The treatment of this infection with anti-interferon antibody stimulated virus replication and extensive c.p.e. However, some cells survived and grew rapidly without any sign of c.p.e. These produced increased amounts (100 to 1000 times) of infectious and DI particles in the presence of anti-interferon antibody, becoming susceptible to superinfection with VSV but remaining resistant to the original rabies virus. Small plaque mutants appeared and replaced the original virus during the long-term cultivation of the persistent infection. Several mutants tested were all identified as Sdi (DI-resistant) mutants, suggesting that the persisting viruses were endowed by the Sdi mutation with a selective advantage over the original virus even in interferon-mediated persistent infections.
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PMID:Persistent infection of rabies virus (HEP-Flury strain) in human neuroblastoma cells capable of producing interferon. 399 11

Human lymphocytes obtained by cytapheresis were stimulated in spinner culture conditions by nonpurified PHA in order to study the production of gamma interferon, and the characterization of IFN-gamma mRNA. Titers of interferon prepared in 0.6 to 4 1 batches, varied in 20 preparations from 8,000 to 32,000 units/ml. This interferon was unstable at pH 2: the residual antiviral activity after 20 h treatment was less than 3%. Antibodies raised against gamma interferon from Con A and SEA-stimulated lymphocytes neutralized the interferon induced by PHA, indicating that all three preparations are antigenically related. Poly(A)RNA from control, noncultivated lymphocytes and from lymphocytes stimulated by PHA for 18 h were translated in reticulocyte lysates and analysed by polyacrylamide gel electrophoresis. The pattern of synthesized polypeptides was different suggesting modifications in the population of mRNA. When total poly(A)RNA was inoculated into Xenopus Laevis oocytes, interferon activity was found with both, control and stimulated mRNAs although only at low levels in the control. After sucrose gradient fractionation of poly(A)RNA, each fraction was inoculated into oocytes and interferon activity measured in the oocyte bathing medium. A low level was synthesized by the RNA fractions around 28 S from control as well as from stimulated lymphocytes. These interferons were not neutralized by anti-IFN-alpha or anti-IFN-gamma sera but they were neutralized by anti-IFN-beta serum. Only the 16 S RNA fraction from PHA-stimulated lymphocytes induced high levels of interferon in oocytes. This interferon has been characterized as gamma interferon. Each fraction obtained from sucrose gradients on poly(A)RNA from control and PHA-stimulated lymphocytes was translated in reticulocyte lysate. Gel analysis of the products showed striking differences when the same fraction of both RNAs were compared. Concerning particularly the 16 S RNA from PHA-stimulated lymphocytes, where gamma interferon mRNA was present, polypeptides ranged from 15 to 55 K with a bulk around 45 K, indicating heterogeneous RNA molecules.
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PMID:Translation of mRNA from phytohemagglutinin-stimulated human lymphocytes: characterization of interferon mRNAs. 612 11

The human hepatoma cell line, PLC/PRF/5, which is persistently infected with hepatitis B virus (HBV), has integrated HBV-DNA, secretes HBV surface antigen (HBsAg), and does not grow readily in congenitally athymic (nu/nu) mice. The present investigation was undertaken to ascertain whether the low tumorigenicity of this cell line was governed by a host immune response and/or was related to expression of HBsAg. Subcutaneous injection of 4-5 X 10(6) cells into BALB/c nude mice produced localized encapsulated tumors with morphologic features of primary hepatocellular carcinoma in 25% of the animals within 29-40 d. No tumor growth was observed at lower cell inocula. In contrast, SK-HEP-1, an HBV-negative human hepatoma cell line, produced tumors at 1-5 X 10(6) cells inocula in 66% of the animals. Immunosuppression of mice with antilymphocyte serum (ALS) or irradiation increased tumor incidence in mice inoculated with 1 X 10(6) PLC/PRF/5 cells to almost 100% and produced local invasiveness. Immunosuppression also reduced the latency, i.e., time to tumor appearance, and increased mean tumor weight. These results suggest that tumorigenicity was limited by the host immune response. The nature of the response was delineated by treating nude mice challenged with tumor cells with sheep anti-mouse interferon globulin (anti-IFN). When 2 X 10(6) cells were injected, tumor growth occurred in 75% of anti-IFN-treated mice, whereas controls injected with the same number of cells, but not receiving anti-IFN, failed to develop tumors. The tumors in the anti-IFN-treated mice were highly invasive and the latency period until tumor appearance was reduced to 3-5 d. An inverse correlation was found between susceptibility of the hepatoma cells to natural killer (NK) activity in vitro and resistance to tumor growth in vivo. In vitro cytotoxicity for PLC/PRF/5 cells was eliminated by anti-NK 1.1 and complement, establishing the effector cell as an NK cell. NK cell activity 14 d after inoculation of mice with PLC/PRF/5 cells was augmented against PLC/PRF/5 target cells but not against SK-HEP-1 cells. Treatment of mice with ALS, irradiation, or anti-IFN abolished NK activity against PLC/PRF/5 cells. Co-cultivation of nude mouse spleen cells with PLC/PRF/5 but not with HBsAg or SK-HEP-1 cells induced secretion of murine IFNalpha. These results suggest that the IFN/NK cell system may play a role in limiting tumorigenicity and invasiveness of HBV-infected human hepatocellular carcinoma cells by a mechanism similar to that found for other cells persistently infected with viruses.
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PMID:Role in nude mice of interferon and natural killer cells in inhibiting the tumorigenicity of human hepatocellular carcinoma cells infected with hepatitis B virus. 619 49

K-104 cells, a cloned cell line derived from a human neuroblastoma (SYM-I), were induced by rabies HEP-Flury virus to release large amounts of interferon, and the resulting antiviral activity significantly suppressed the rabies virus replication. The role of endogenous interferon was confirmed by treatment with anti-interferon antibody which increased the yield of progeny virus. The virus yield in the second undiluted passage through K-104 cells was much less than that in the first passage, because of the antiviral state initiated by brief contact of interferon present in the virus inoculum with cells during the short period of virus adsorption. When the m.o.i. was relatively low, as in the third undiluted passage, the effect of interferon present in the inoculum was enhanced and most of the infected cells survived but were shown to be in a state of persistent infection. Defective interfering (DI) particles did not accumulate rapidly during these three undiluted passages. When Sindbis virus was used for infection, the endogenous interferon system of K-104 cells was not activated during 12 undiluted passages. However, on the 12th passage, the yield began to decline due to the generation and accumulation of DI particles.
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PMID:Comparative studies of rabies and Sindbis virus replication in human neuroblastoma (SYM-I) cells that can produce interferon. 620 14


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