Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
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The biochemical structure of CD69 early activation antigen has been characterized by means of two newly isolated mAb, namely C1.18 and E16.5. Upon analysis by SDS-PAGE, C1.18-reactive molecules immunoprecipitated from 125I-surface labeled PMA activated PBL consisted of a 32 + 32 kD dimer, a 32 + 26 kD dimer, a 26 + 26 kD dimer and a 21 + 21 kD dimer. E16.5-reactive molecules consisted of a 26 + 26 kD dimer and a 21 + 21 kD dimer. Cross absorption experiments showed that E16.5 mAb reacts with an epitope of the CD69 molecule distinct from the one recognized by C1.18 mAb and present only on a subpopulation of the CD69 molecular pool. The patterns of migration of C1.18- and E16.5-reactive molecules in two-dimensional gel-electrophoresis, under reducing conditions before and after treatment with Endoglycosidase F enzyme suggest that the two mAb recognize the same glycoprotein structure, but in two distinct glycosylation forms, both expressed on the cell surface membrane. Finally, p32, p26 and p21 of CD69 complex obtained from three distinct normal donors did not show appreciable structural polymorphism, by two-dimensional peptide mapping, not only among single subunits within the same individual, but also among homologous subunits in distinct individuals. Further, it was found that CD69 complex is expressed at the cell surface of resting PBL, although at a very reduced level in comparison to PMA activated cells. C1.18 and E16.5 mAb induced comparable cell proliferation and IL-2 production in PBL in the presence of PMA. C1.18 mAb increased intracellular free calcium concn in PMA activated PBL after cross-linking with goat anti mouse Ig, while the effect induced by E16.5 mAb after cross-linking was consistently lower. Finally, it was found that Sepharose-linked C1.18 mAb, in the presence of rIL-2 or PMA, did not induce TNF release from 6 NK cell clones.
Mol Immunol
PMID:Structural analysis of the CD69 early activation antigen by two monoclonal antibodies directed to different epitopes. 170 36

TNF alpha is a cytokine which causes cytolysis of tumour cell lines in vitro as well as haemorrhagic necrosis of many transplanted tumours in vivo. In association with these activities, the cytokine manifests a high degree of toxicity in vivo. The in vitro and in vivo effects of a panel of 13 monoclonal antibodies against human TNF alpha have been investigated. Of these MAbs, eight neutralized TNF alpha activity in the WEHI-164 cytotoxicity assay as well as in the binding of TNF alpha to receptors on these cells. The effects of this group of antibodies on TNF alpha-induced regression of WEHI tumours in vivo correlated with their in vitro neutralizing activities. One MAb which inhibited cytotoxicity, receptor interaction and tumour regression in the WEHI model (MAb 37) failed to inhibit TNF alpha-receptor binding and tumour regression in Meth A models. This observation indicates that different classes of receptor specificity may exist on different tumour cells. Together the antibodies define six non-overlapping epitopic domains on TNF alpha and within these regions there are at least nine overlapping epitopes. Inhibitory MAbs, when co-injected into tumour-bearing mice with radiolabelled TNF alpha, resulted in the diversion of TNF alpha away from both tumour and lung, which correspond to the sites of highest TNF alpha uptake in control MAb-TNF alpha treated mice. In contrast, uptake of TNF alpha by the liver was increased and overall, biodistribution studies showed that very little TNF alpha reached the target tumour but was rapidly and widely dispersed throughout the body. Preliminary studies with these MAbs show that segregation of TNF alpha activities and receptor binding may be possible.
Mol Immunol
PMID:Antigenic structure of human tumour necrosis factor: recognition of distinct regions of TNF alpha by different tumour cell receptors. 170 38

The role of cytokines in vivo has been difficult to assess. This difficulty is due, in part, to the limited number of producer cells and the strict regulation of cytokine production. In order to address this situation, we have developed assays which allow us to quantitate both protein production and steady state mRNA levels from specific in vivo sites. In this report, we present data utilizing these assays on cells obtained from draining LN following specific sensitization with antigen in vivo. In order to determine the relative quantities of cytokine mRNA, we modified the reverse transcriptase-polymerase chain reaction which had been previously described. The modified assay is (1) linear over a large concn range of input template (2) demonstrates a high degree of reproducibility (SE approximately 13%) and (3) is very sensitive. Utilizing this assay, we have measured a constitutive mRNA (DHFR), quantitated both the presence of lymphokine mRNA (IL-2) and the induction of cytokine mRNA (TNF alpha). In this report we have examined the kinetics of TNF alpha mRNA expression and have demonstrated that following epicutaneous sensitization with picryl chloride, there is rapid induction (within 24 hr) of TNF alpha mRNA in the draining LN and that the levels of mRNA remain detectable through d7. In addition, we determined the time course of production of TNF protein by the draining LN cells and found that it was similar to that of the mRNA levels. A potential pathologic role for immune response generated TNF alpha is also discussed. We believe these experiments demonstrate that cytokine production following antigen-specific sensitization in vivo can be analyzed at both the cellular and molecular level. The data suggests that this approach can be used to study cytokine regulation in vivo.
Mol Immunol
PMID:Quantitation of cytokine mRNA levels utilizing the reverse transcriptase-polymerase chain reaction following primary antigen-specific sensitization in vivo--I. Verification of linearity, reproducibility and specificity. 171 71

The role of amino functions in the expression of the biological activity of recombinant human TNF (rHuTNF) was studied by chemical modification. rHuTNF is a homotrimer of 17 kD subunits, each of which contains an N-terminal valine and six lysyl residues: two of these lysyl residues are known to be involved in intra- or intersubunit interactions. Chemically reactive amino functions were modified with the N-hydroxysuccinimide ester of acetic acid; modification of amino groups to amide, and the concomitant loss of charge, was monitored by native PAGE. When rHuTNF was reacted with the active ester at increasing mole ratios, up to 12 amino groups per trimer could be modified. When the biological activity of acetylated rHuTNF was determined, a strong correlation between the extent of modification and loss of biological activity was observed. One to three amino groups per trimer could be modified with nearly complete retention (approximately 80-95%) of biological activity; activity was essentially completely destroyed at the highest levels of modification. These results reveal important functions for the amino groups of rHuTNF and significant constraints on strategies involving their modification in development of second-generation-TNF variants.
Mol Immunol 1992 Jan
PMID:The role of amino functions in recombinant human tumor necrosis factor in expression of biological activity. 173 Nov 93

To determine the role of TNF-driven inflammation in self-regulation of cell growth and differentiation, mouse liver regeneration after partial hepatectomy was examined for TNF-driven inflammation. Hepatectomy provoked priming state for TNF production in both whole body and liver on day 3 when the peak mitotic response occurred. Histochemical studies of liver also showed an inflammatory symptom; hepatocellular necrotic foci appeared by 6 hours after hepatectomy. TNF itself was secreted spontaneously in liver transiently on day 1 to 2 after hepatectomy just before the proliferation of hepatocytes. Dexamethasone reduced both TNF secretion and hepatocyte proliferation after hepatectomy. Recombinant murine TNF stimulated the in vitro proliferation of hepatocytes. These findings indicate that hepatectomy induces short-term secretion of TNF in liver and TNF-driven inflammation has an important role in liver regeneration, at least in part by the direct stimulation of hepatocyte proliferation.
Mol Biother 1991 Sep
PMID:TNF-driven inflammation during mouse liver regeneration after partial hepatectomy and its role in growth regulation of liver. 183 62

The metabolism of estrone (E1) and estradiol (E2) by Ishikawa endometrial carcinoma cells and its alteration by TNF alpha treatment was studied. Whereas this cell line practically does not respond to estrogens, it is very sensitive to TNF with respect to growth inhibition and other parameters. E2 and E1 were found to be metabolized by this cell line whereby the main metabolite for both estrogens was estriol. TNF significantly increased the rate of E1 and E2 conversion.
J Steroid Biochem Mol Biol 1991 Aug
PMID:Metabolism of E1 and E2 in Ishikawa endometrium carcinoma cells: influence of TNF alpha. 188 80

Murine monoclonal antibody ZME-018 recognizes a 240 Kda glycoprotein present on the surface of most human melanoma cells and on over 80% of human biopsy specimens tested. Gelonin is a ribosome-inactivating plant toxin similar in nature and rivaling the activity of ricin A chain. ZME-018 was coupled to purified gelonin using the reagents SPDP and 2-iminothiolane. The ZME-gelonin conjugate was purified by S-300 Sephacryl and Blue Sepharose chromatography, removing unreacted gelonin and antibody, respectively. PAGE analysis showed that ZME was coupled to 1, 2, or 3 gelonin molecules. The ZME-gelonin conjugate was 10(6)-fold more active than gelonin itself in inhibiting the growth of log-phase human melanoma cells in culture. The immunoconjugate was not cytotoxic to antigen negative T-24 (human bladder carcinoma) cells. Treatment of melanoma cells with recombinant IFN-alpha or TNF substantially augmented the cytotoxicity of the immunoconjugate while treatment with IFN-gamma had a minor effect. Using the human tumor colony assay of melanoma cells obtained from fresh biopsy specimens, greater than 90% growth suppression was observed in 2 of 4 samples tested at a concentration of 250 ng/ml. In addition, 25% growth suppression was observed with a third sample tested, and no growth suppression was observed in 1 sample. Thus, clonogenic melanoma cells are sensitive in vitro to the cytotoxic activity of this immunotoxin at concentrations which we presume are pharmacologically relevant.
Mol Biother 1991 Mar
PMID:A specific and potent immunotoxin composed of antibody ZME-018 and the plant toxin gelonin. 190 86

The activation of NF-kappa B-like activities (called NF-kappa B) by tumor necrosis factor alpha (TNF alpha) and the phorbol ester phorbol 12-myristate 13-acetate (PMA) were compared. High levels of NF-kappa B activity were found 2 to 4 min after TNF alpha addition to human HL60 cells and lasted for at least 3 h, although the half-life of active NF-kappa B was less than 30 min. Inactive NF-kappa B, however, was relatively stable. NF-kappa B activation by TNF alpha was initially cycloheximide insensitive, but maintenance of NF-kappa B activity required ongoing protein synthesis and continuous stimulation by TNF alpha. Thus, the cells did not remain in an activated state without stimulation. In HL60 cells, NF-kappa B induction by PMA required 30 to 45 min and was completely dependent on de novo protein synthesis, while PMA (and interleukin-1) induced NF-kappa B activity rapidly in mouse 70Z/3 cells via a protein synthesis-independent mechanism. The NF-kappa B-like activities obtained under each condition behaved identically in methylation interference and native proteolytic fingerprinting assays. The NF-kappa B-like factors induced are thus all very similar or identical. We suggest that cell-specific differences in the protein kinase C-dependent activation of NF-kappa B may exist and that TNF alpha and PMA may induce expression of the gene(s) encoding NF-kappa B.
Mol Cell Biol 1991 Jan
PMID:Maintenance of NF-kappa B activity is dependent on protein synthesis and the continuous presence of external stimuli. 198 24

The peptide regulatory factors (PRFs), variously termed cytokines, lymphokines, interleukins, colony stimulating factors, interferons, etc., play a key role in the quantitative and qualitative regulation of protective responses--both in initiating immunological and inflammatory responses and in mediating and controlling the effector mechanisms that protect the body against micro-organisms. The process of immunization--involving antigen-presentation, lymphocyte-activation and clonal proliferation--depends on the action of a variety of PRFs. The function of accessory cells--the dendritic cells, macrophages, etc.--is stimulated by PRFs such as interferon-gamma, IL-1, TNF, GM-CSF and IL-4. The activation and expansion of T-lymphocytes requires IL-1, IL-2, IL-4, interferon-gamma, IL-6 and probably IL-7. Likewise, the activation and expansion of B-lymphocytes is regulated by PRFs such as IL-1, IL-2, IL-4, IL-5, IL-6, IL-7 and interferon-gamma. It is likely, although unproven, that PRFs also regulate the differentiation of B-cells to memory cells. Successful vaccination requires the immune system to be primed in such a way that natural challenge with a micro-organism or its products evokes an immune response that has the qualitative and the quantitative characteristics of both the humoral and cellular responses. Antibody class is critically influenced by particular PRFs, e.g. interferon-gamma regulates IgG2a; IL-4, IgE and IgG1; IL-5 and TGF-beta, IgA. PRFs are both produced by and regulate the T-lymphocytes which have key roles in protective responses--either directly, viz. the cytotoxic T-lymphocytes important in protection against certain viruses, or indirectly through the secretion of PRFs that regulate the speed, magnitude and quality of antibody cellular responses. The recruitment and enhanced production and function of granulocytic and phagocytic cells involves a number of T-lymphocyte PRFs including GM-CSF, IL-3, IL-5, IL-4, and IL-6. We do not have a good understanding of the fine-tuning of cellular responses nor of how infection with different pathogens results in different types of inflammatory responses; it is clear, however, that certain cellular responses are due to the action of specific PRFs, e.g. IL-3 induces a mastocytosis and IL-5 an eosinophilia. There is increasing evidence that the relative levels of different PRFs are important determinants of the effectiveness of responses.(ABSTRACT TRUNCATED AT 400 WORDS)
Mol Immunol 1991 Mar
PMID:Peptide regulatory factors and optimization of vaccines. 201 99

We examined expression and cytotoxic triggering capability of the three Fc receptors for IgG (Fc gamma R) on human monocytes, PMNs and myeloid cell lines after in vitro culture with various cytokines. Fc gamma R expression was evaluated using specific anti-Fc gamma R monoclonal antibodies (mAb). The cytotoxic capability of each Fc gamma R was examined after the effector cells were treated with the recombinant cytokines IFN-gamma. TNF alpha, GM-CSF, G-CSF, M-CSF, IL-1, IL-2, IL-3, IL-4, or IL-6. Hybridoma cell lines (HC) bearing antibody directed to Fc gamma RI (HC 32), Fc gamma RII (HC IV.3) or Fc gamma RIII (HC 3G8) were used as targets, as were chicken erythrocytes (CE) sensitized with heteroantibodies composed of anti-Fc gamma R mAbs (32, IV.3, 3G8) linked to anti-CE antibody. Only IFN-gamma treatment significantly increased Fc gamma R expression and then only Fc gamma RI. IFN-gamma dramatically up-regulated Fc gamma RI expression on all cells tested. However, ADCC was enhanced by treatment with a number of cytokines other than IFN-gamma. GM-CSF, TNF, and IFN-gamma treatment enhanced killing of HC 32 and HC IV.3 by in vitro cultured monocytes. G-CSF treatment enabled PMNs to kill HC through Fc gamma RII, whereas PMN killing of HC through Fc gamma RIII could not be induced by any of the cytokines studied. Although only IFN-gamma treatment increased ADCC of CE by monocytes, GM-CSF treatment as well as IFN-gamma treatment augmented ADCC of CE by PMNs. In addition to IFN-gamma treatment, IL-6 treatment enabled U937 cells to lyse CE. Whereas IFN-gamma-treated U937 cells killed CE through both Fc gamma RI and Fc gamma RII, IL-6-treated U937 cells killed CE only through Fc gamma RI. In addition to IFN-gamma treatment, G-CSF treatment enabled HL-60 cells to lyse CE through both Fc gamma RI and Fc gamma RII. These results demonstrate that although IFN-gamma appears unique in regulating Fc gamma R expression on myeloid cells, cytokines other than IFN-gamma affect ADCC by these cells in a receptor-specific manner.
Mol Immunol 1990 Jan
PMID:The effect of cytokines on the expression and function of Fc receptors for IgG on human myeloid cells. 213 46


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