Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0009443 (cold)
 92,137 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report here that cytotoxic pretreatment of spleen cells from six different strains of young adult mice with a monospecific rabbit antiserum against macromolecular insoluble cold globulin (MICG) effectively abrogates spontaneous NK activity directed towards YAC-1 tumour cells. MICG is a 225,000 molecular weight glycoprotein that is present in the plasma membrane of adult thymocytes and peripheral T cells, as well as in embryonic prothymocytes, but absent in granulocytes and B lymphocytes. The diminished NK activity in lymphocyte populations selectively depleted of MICG+ cells could not be restored by in vitro exposure to the NK boosting agents interleukin-2 (IL-2) and interferon. Lymphokine-activated spleen NK cells, generated by 48 hr preculture with IL-2 or interferon, expressed high levels of MICG surface antigen, moderate amounts of Thy 1.2 and, in striking contrast to spontaneous NK, very low to negligible amounts of AsGM1. Likewise, spontaneous NK cells in bone marrow were also shown to be both MICG+ and AsGM1+, while lymphokine-activated bone marrow NK cells remained MICG+, but lacked AsGM1. Thus, a clear distinction could be observed between spontaneous and activated NK cells with respect to differential expression of MICG and AsGM1. MICG was also detected on ADCC effector cells, whereas no surface MICG could be found on NC cells. These data are in line with the view that at least certain types of NK cells develop along a common lineage with T lymphocytes in the mouse.
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PMID:Identification of macromolecular insoluble cold globulin (MICG) as a new marker shared by NK and ADCC cells, but not expressed by NC cells. 242 32

During inflammation polymorphonuclear cells (PMNs) are exposed to agonistic stimuli including activated complement, kallikrein, arachidonic acid metabolites, monokines, and platelet-activating factor (PAF). We report that PAF not only directly activates PMNs but in miniscule quantities (10(-12) mol/L) "primes" them as well, that is, permits PMNs to respond to subsequent stimuli that would be otherwise ineffectual. PAF priming of responses including superoxide generation, elastase release, and aggregation is time dependent and is maximal within five minutes. PAF need not be present during the subsequent exhibition of PMN agonists, but priming is inhibited by cold and is also inhibited by the PAF receptor antagonists BN 52021, L-652, and kadsurenone. An intact PAF molecule is required because lyso-PAF and methoxy-PAF do not prime PMN responses. PAF priming is associated with both enhanced expression of the adhesive glycoprotein identified by OKM-1 antibody and an enhanced rise in intracellular calcium levels in response to the subsequent addition of agonists such as FMLP. PMNs primed with PAF and stimulated with either F-Met-Leu-Phe or phorbol esters are more effective in lysing and detaching cultured human endothelial cells--damage that can also be inhibited by the PAF antagonists. Because PAF is synthesized and exhibited on surfaces of endothelial cells perturbed by coagulation, we suggest that this lipid may potentiate otherwise trivial activators of marginated PMNs so that they become damaging to the PAF-synthesizing endothelium itself. If so, our studies suggest a possible therapeutic role for PAF inhibitors in excessive inflammatory states.
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PMID:Platelet-activating factor primes neutrophil responses to agonists: role in promoting neutrophil-mediated endothelial damage. 245 47

We have cloned blood trypomastigotes from infected mice and found that Trypanosoma cruzi strains are composed of heterogeneous populations that dramatically vary (more than 100 fold) in their abilities to attach to and enter rat heart myoblasts. Trypomastigote clones were distinctively separated into highly and weakly infective groups presenting higher and lower rates of attachment to myoblasts, respectively. Each trypomastigote clone maintained the same profile of attachment and internalization into heart myoblasts when tested at different periods of time. This pattern did not change when the parasites were incubated in fresh medium before being exposed to heart myoblasts. Highly and weakly infective clones show differences at the cell surface level, particularly with regard to a 83 kDa glycoprotein. We have identified this 83 kDa glycoprotein as the parasite membrane ligand that specifically binds to rat heart myoblasts. The binding of the biotinylated 83 kDa to myoblasts is inhibited by cold excess in Western blots, as indicated by laser densitometry. In addition, the specific binding of this molecule to myoblasts is saturable and is greater in highly than in weakly infective trypomastigote clones. Highly invasive trypomastigote clones express this glycoprotein in more abundance on their surface than weakly infective trypomastigote clones. These results indicate that the 83 kDa glycoprotein present on the surface of T. cruzi trypomastigotes mediates the attachment of the parasite to heart myoblasts.
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PMID:Trypanosoma cruzi trypomastigote clones differentially express a parasite cell adhesion molecule. 265 21

Avian RNA tumor virus envelope glycoprotein protects against sarcoma development by an avian sarcoma virus of the same subgroup. Avian RNA tumor viruses, members of the retrovirus family, induce various malignancies in fowl (Weiss et al. (eds.), 1982, RNA Tumor Viruses, Cold Spring Harbor, N.Y.). These viruses consist of a genomic RNA core surrounded by an envelope with embedded glycoproteins, of 85 and 37 kDa. The 85 kDa glycoprotein is antigenically specific for each subgroup as determined by neutralization. The envelope glycoprotein can be removed from the virion with retention of its antigenicity (Duesberg et al., 1970, Virology 41, 631-646). Two fractions of 4-6S and 8S, separated by sedimentation, were shown to retain antigenicity by interference of neutralization of virus by antibody. Thus, the 4-6S and 8S preparations could possibly serve as immunogens. The objective of this study was to determine if such envelope glycoprotein preparations could function as potential vaccines, and if so, whether the protection afforded would be subgroup specific.
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PMID:Immunization with envelope glycoprotein of an avian RNA tumor virus protects against sarcoma virus tumor induction: role of subgroup. 282 7

Vaccines against parainfluenza (PIV) and respiratory syncytial viruses (RSV) that are currently being developed include both live and subunit vaccines. Candidate live PIV vaccines that have been found to be attenuated and efficacious in rodents or primate models are (1) cold-adapted, temperature-sensitive mutants of PIV-type 3 that have been serially passaged at low temperature (20 degrees C) in simian kidney tissue culture; (2) protease-activation mutants (PIV-1-Sendai), which have mutations that decrease the cleavability of their F glycoprotein by host cell protease; (3) an animal virus, bovine PIV-3 virus, which is antigenically related to the human PIV-3 virus, and (4) vaccinia recombinant viruses bearing RSV or PIV-3 glycoproteins. Subunit RSV and PIV-3 viruses are being produced and evaluated as immunogens. A major concern with these vaccines is the possibility of disease potentiation following virus infection as occurred previously with formalin-inactivated measles and RSV vaccines. Studies indicate that PIV-3 and RSV glycoprotein vaccines are immunogenic and efficacious in animals but insufficient data exist to estimate their capacity to potentiate disease. However, since a cotton rat model is available to detect potentiated disease resulting from infection of cotton rats previously immunized with formalin-inactivated RSV vaccine, it is now possible to systematically evaluate new vaccines in experimental animals for disease potentiation before studies are initiated in humans. It is likely within the next several years that one or more of these PIV or RSV vaccines will be tested in humans for safety and immunogenicity.
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PMID:Current approaches to the development of vaccines effective against parainfluenza and respiratory syncytial viruses. 284 80

Natural killer (NK) cells lyse tumor and virus-infected cells yet the nature of the target structure they recognize is unknown. A normal host cell glycoprotein, the transferrin receptor (TfR), has been proposed as a target structure on tumor cells. We therefore investigated whether changes in the number or physiological recycling of the TfR, consequent on virus infection, were related to the differential susceptibility of virus-infected cells to NK lysis. There was a direct correlation between TfR expression, susceptibility to NK lysis and ability to act as cold target competitors, for human fibroblasts infected with RNA and DNA viruses (cytomegalovirus, herpes simplex, polio, vaccinia and Semliki Forest virus). The NK lysis of human cytomegalovirus-infected fibroblasts was studied in more detail. NK lysis was increased coincident with human cytomegalovirus early antigen expression and this susceptibility to lysis was associated with increased total and recycling TfR but only a slight increase in surface TfR expression. In addition, susceptibility of uninfected human fibroblasts to NK lysis directly correlated with TfR number. However, we were unable to inhibit NK lysis by either excess iron-saturated Tf or affinity-purified TfR. We conclude that there is a direct correlation between total TfR expression and susceptibility to NK lysis of human virus-infected cells; however, the NK target structure on virus-infected cells is probably not the TfR itself.
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PMID:Human natural killer cell lysis of virus-infected cells. Relationship to expression of the transferrin receptor. 300 2

The cold agglutinin isolated from the albumin gland of the snail Achatina fulica was modified with various chemical reagents in order to detect the amino acids and/or carbohydrate residues present in its carbohydrate-binding sites. Treatment with reagents considered specific for modification of lysine, arginine and tryptophan residues of the cold agglutinin did not affect the carbohydrate-binding activity of the agglutinin. Modification of tyrosine residues showed some change. However, modification with carbodiimide followed by alpha-aminobutyric acid methyl ester causes almost complete loss of its binding activity, indicating the involvement of aspartic acid and glutamic acid in its carbohydrate-binding activity. The carbohydrate residues of the cold agglutinin were removed by beta-elimination reaction, indicating that the sugars are O-glycosidically linked to protein part of the molecule. Removal of galactose residues from the cold agglutinin by the action of beta-galactosidase indicated that the galactose molecules are beta-linked. These carbohydrate-modified glycoproteins showed a marked change in agglutination property, i.e. they agglutinated rabbit erythrocytes at both 10 degrees C and 25 degrees C, indicating that the galactose residues of the glycoprotein play an important role in the cold-agglutination property of the glycoprotein. The c.d. data showed the presence of an almost identical type of random-coil conformation in the native cold agglutinin at 10 degrees C and in the carbohydrate-modified glycoprotein at 10 degrees C and 25 degrees C. This particular random-coil conformation is essential for carbohydrate-binding property of the agglutinin.
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PMID:Studies on chemical modification of cold agglutinin from the snail Achatina fulica. 311 67

Using both fluorescent labelled toxin and antibody--secondary antibody techniques, the Bacillus sphaericus toxin was found to bind strongly to susceptible Culex quinquefasciatus cells, but far less strongly to cells of insensitive insects. An insensitive clone of the C. quinquefasciatus cell line was discovered which bound toxin efficiently. The toxin was bound in the cold to sensitive cells and these cells could be rescued from cytotoxicity for ca. 15 min after warming, by which time toxin appeared to be internalized. Binding was saturable. This toxin is apparently internalized by receptor-mediated endocytosis, probably involving a glycoprotein receptor containing N-acetyl-D-glucosamine. Evidence for toxin binding to lipids was not found. Antibody appeared to detect internalized toxin, and high concentrations of sugars inhibited cytotoxicity; these results along with evidence from a recent ultrastructural study suggest that this toxin may form pores in the cell membrane.
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PMID:Binding of the Bacillus sphaericus mosquito larvicidal toxin to cultured insect cells. 312 70

Gastric mucus content was morphometrically evaluated in gastric glands of normal and cold-restraint stressed rats. Variations induced by treatment with zinc acexamate (200 mg/kg p.o.) were also investigated. Stress decreased the glycoprotein content in glands located in areas of injury. However, in intact glands from the same animals, the glycoprotein content was increased and the proportion of sulphated macromolecules greatly augmented. Zinc acexamate reduced the severity of damage in stressed rats. Although it augmented mucus content it prevented the modification in sulphated macromolecules in these rats. These findings are discussed in relation to the role of gastric mucus in preventing gastric damage.
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PMID:Effect of cold-restraint stress and zinc acexamate on gastric mucus production in intact glands. 344 37

We have previously shown that platelet glycoprotein Ib is expressed in a minority of cells of the human leukemic cell line HEL (Tabilio, A., Rosa, J. P., Testa, U., Kieffer, N., Nurden, A. T., Del Canizo, M. C., Breton-Gorius, J., and Vainchenker, W. (1984) EMBO J. 3, 453-459). In this report, we have selected a stable HEL subclone with increased expression of glycoprotein (GP) Ib as assessed by 6 different monoclonal antibodies in order to investigate the biochemical characteristics of this glycoprotein. A single polypeptide chain of apparent Mr = 60,000 was precipitated under reducing and nonreducing conditions by a specific polyclonal anti-platelet glycocalicin antibody and two anti-GPIb alpha monoclonal antibodies (AN51 and AP1), both from surface-labeled and metabolically labeled HEL cells. We were unable to demonstrate the presence of a polypeptide corresponding to the beta subunit of GPIb or GPIX which is closely associated with GPIb. Competitive immunoprecipitation performed in the presence of an excess amount of cold platelet glycocalicin completely displaced the Mr = 60,000 polypeptide. Synthesis of N-linked oligosaccharide chains on this Mr = 60,000 polypeptide was inhibited by the antibiotic tunicamycin, and a shift of the apparent Mr from 60,000 to 48,000 was observed. O-Linked oligosaccharide chains identical to platelet GPIb hexasaccharides were deficient or incomplete since no peanut agglutinin binding to the Mr = 60,000 polypeptide was observed after neuraminidase treatment of HEL cells. Thus, our results provide evidence that the Mr = 60,000 polypeptide expressed on the surface membrane of HEL cells is closely related to platelet GPIb and corresponds to an incompletely or abnormally O-glycosylated GPIb alpha subunit.
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PMID:Expression of platelet glycoprotein Ib alpha in HEL cells. 346 23


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