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K W Moore

Publications and source records attributed to K W Moore.

72 records · Page 4Linked to original sources
PubMed1989

Human Fc gamma RIII: cloning, expression, and identification of the chromosomal locus of two Fc receptors for IgG.

A cDNA clone encoding a human receptor for the Fc portion of IgG (Fc gamma R), Fc gamma RIII or CD16, was isolated from a human leukocyte library by a transient expression-immunoselection procedure. This cDNA (pGP5) encodes a 46-kDa phosphatidylinositol-linked cell surface protein with CD16 determinants and affinity for human IgG. The deduced protein sequence is most homologous to the murine receptor Fc gamma RII alpha, with slightly less homology to the human receptors Fc gamma RII and Fc epsilon RI. The cDNA hybridizes to a 2.2 kilobase mRNA in human leukocytes and a cloned human natural killer cell line. Fc gamma RIII is mapped to chromosome 1 by spot-blot analysis of sorted human chromosomes. Hybridization of Fc gamma RII and Fc gamma RIII probes to restriction digests of human genomic DNA separated by pulsed-field gel electrophoresis demonstrates physical linkage of the two genes within a maximum distance of 200 kilobases. The results identify a locus for at least two Fc gamma R genes on human chromosome 1.

Amino Acid Sequence↗
PubMed1988

Cloned and expressed human Fc receptor for IgG mediates anti-CD3-dependent lymphoproliferation.

We have utilized gene transfer experiments to investigate the role of a human monocyte receptor for IgG (Fc gamma RII) in mouse IgG1 anti-CD3 (Leu 4)-induced lymphoproliferation in vitro. Mouse Ltk- cells expressing human Fc gamma RII or a mutant of Fc gamma RII lacking the entire cytoplasmic domain of the receptor mediate anti-CD3-induced lymphoproliferation in cultures of adherent cell-depleted human PBMC. Expression of an Fc gamma RII mutant lacking transmembrane and cytoplasmic domains (soluble Fc gamma RII) in COS7 cells yielded a secreted receptor which retained affinity for IgG, even in the absence of the mutant receptor's N-linked oligosaccharides. Soluble Fc gamma RII inhibits rosette formation by human IgG-sensitized RBC and the Fc gamma RII-bearing cell line K562, but does not sitmulate anti-CD3-induced lymphoproliferation under the conditions tested.

Animals↗
PubMed1987

Isolation and expression of cDNA clones encoding a human receptor for IgG (Fc gamma RII).

We have cloned and expressed a cDNA encoding a human receptor for IgG (Fc gamma R) from the monocyte cell line U937. The deduced structure is a 35-kD transmembrane protein with homology to the mouse Fc[gamma 2b/gamma 1] receptor amino acid sequence of approximately 60% in the extracellular domain. The signal sequence is homologous to the mouse Fc gamma R alpha cDNA clone, while the transmembrane domain shares homology with mouse Fc gamma R beta cDNAs. The cytoplasmic domain is apparently unique. The extracellular domain shows significant homology to proteins of the Ig gene superfamily, including the human c-fms protooncogene/CSF-1 receptor. Mouse Ltk- cells transfected with the human Fc gamma R cDNA express a cell-surface receptor that selectively binds human IgG and is recognized by the anti-Fc gamma RII mAb IV.3. Antibodies against peptides derived from the human Fc gamma R sequence specifically stain U937 cells, but not an Fc gamma RII-bearing B-lymphoblastoid cell line (Daudi). These results identify the human Fc gamma RII as the homologue of mouse Fc[gamma 2b/gamma 1] R, and provide evidence for heterogeneity of Fc gamma RII expressed on monocytes and B cells.

Amino Acid Sequence↗
PubMed1987

Potentiating and suppressive IgE-binding factors are expressed by a single cloned gene.

We have investigated expression of an IgE-binding factor (IgE-BF) cDNA in both COS-7 monkey kidney cells and Chinese hamster ovary cells. Transient expression of the IgE-BF clone in either cell type yielded IgE-BF, which potentiated an in vitro IgE response and had an affinity for lentil lectin. In contrast, when the transient expression experiments were carried out in the presence of tunicamycin, the factors no longer bound to lentil lectin. Moreover, IgE-BF expressed under these conditions suppressed an in vitro IgE response. IgE-BF lacking affinity for lentil lectin and suppressing the IgE response also resulted from transient expression of the IgE-BF gene in the presence of glycosylation inhibiting factor, a phospholipase inhibitory protein. Thus, IgE-BF that either potentiate or suppress the IgE response can be expressed from a single cloned gene; the difference in biological activities appears to be determined principally by the type of glycosylation of the common polypeptide chain. Previous work showed that IgE-BF bears an antigenic determinant recognized by the anti-Ia monoclonal antibody OX3. IgE-BF produced in the presence of tunicamycin, and IgE-BF expressed from a mutant cDNA lacking one of two carbohydrate-attachment sites, lacked the OX3 determinant. Thus, the OX3 determinant on IgE-BF appears to be associated with a site of N-linked glycosylation.

Amino Acid Sequence↗
PubMed1986

Rodent IgE-binding factor genes are members of an endogenous, retrovirus-like gene family.

Synthesis of IgE by B lymphocytes can be regulated by soluble lymphocyte factors which have affinity for the Fc region of IgE (IgE-binding factors). In previous studies, we identified cDNA clones encoding rodent IgE-binding factors by direct expression in transfected mammalian cells. Here we show that IgE-binding factor cDNA clone 8.3 is a member of the endogenous, retrovirus-like intracisternal A-particle gene family of the mouse. This conclusion is supported by blot hybridization, DNA sequence comparisons, heteroduplex analysis, and immunochemical cross-reactivity of the encoded proteins. The results identify a member of this highly reiterated gene family with a role in regulation of the allergic immune response.

Absorption↗
PubMed1986

cDNA clones encoding murine IgE-binding factors represent multiple structural variants of intracisternal A-particle genes.

Previously [Moore, K. W., Jardieu, P., Mietz, J. A., Trounstine, M. L., Kuff, E. L., Ishizaka, K. & Martens, C. L. (1986) J. Immunol. 136, 4283-4290], we examined a T-hybridoma-derived cDNA clone, 8.3, that encodes a biologically active murine IgE-binding factor (IgE-BF), and we showed that it was a variant member of the endogenous retroviral gene family related to mouse intracisternal A particles (IAPs). We have now characterized four more IgE-BF cDNA clones by heteroduplex and restriction enzyme analysis and found that they all represent different structural variants of the full-size IAP genomic element. In clones 8.3 and 10.2, which have been fully sequenced, the open reading frames span deletions 3.4 and 1.9 kilobases (kb) long, respectively, and specify different gag-pol fusion polypeptides. Clone 9.5 contains a 2.1-kb deletion entirely within the pol region. Two other clones (4.2 and 11.7) contain no internal deletion and may represent truncated cDNA copies of full-size (7.2 kb) IAP gene transcripts. Structural variants very similar to clone 10.2 are common in the mouse genome, and clone 9.5 is also probably not a unique gene form. The sequences of clones 8.3 and 10.2 are different in detail, but each is closely homologous to a randomly cloned mouse genomic IAP element throughout the gag-related portions of their open reading frames. Antibodies against two oligopeptides specified by the sequence of clone 8.3 immunoprecipitated IAP-related proteins from mouse neuroblastoma and myeloma cells, confirming that the IgE-BF produced by this clone shares sequence with expressed IAP elements in different cell types. Thus, information related to the IgE-BF is an integral part of the murine IAP retrotransposon gag gene.

Amino Acid Sequence↗
PubMed1985

cDNA clones encoding IgE-binding factors from a rat-mouse T-cell hybridoma.

cDNA clones encoding rodent IgE-binding factors (IgE-BF) were isolated from cDNA libraries of a rat-mouse T hybridoma that secretes IgE-suppressive factor (IgE-SF) upon incubation with rat IgE. COS7 cells transfected with two of the cDNAs expressed IgE-BF, which selectively potentiate an in vitro IgE response. IgE-BF expressed in COS7 cells are glycoproteins of approximately equal to 60 and approximately equal to 11 kDa. DNA sequence analysis of an IgE-BF cDNA revealed a 556-amino acid (62 kDa) protein coding region. The results suggest that IgE-potentiating and IgE-suppressive factors share common precursor polypeptides and that the 11-kDa IgE-BF is derived from a 60-kDa precursor.

Amino Acid Sequence↗
PubMed1985

IgE-binding factors. Selective regulation of the IgE response by T cell factors.

Gene cloning of rodent IgE-binding factors was accomplished, using messenger RNA of a rat T cell hybridoma, 23B6, which produce IgE-suppressive factor. Transfection of cos 7 monkey kidney cells with a cDNA clone resulted in the formation of rodent IgE-potentiating factors. The results provided a definitive evidence that IgE-binding factors represent a single peptide chain, and that the IgE-potentiating factor and IgE-suppressive factor share a common structural gene. Nucleotide sequence of a cDNA provided predicted amino acid sequence of the 60K precursor molecules of IgE-potentiating factor. Human IgE-potentiating factors were obtained from a human T-T hybridoma. The factors have affinity not only for human IgE but also for rat IgE and selectively enhanced antigen-induced IgE response of rat lymphocytes. The same hybridoma could be switched to form IgE-suppressive factor by the addition of glycosylation-inhibiting factor (GIF) during its biosynthesis. Purified GIF has immunosuppressive activity in the mouse. This factor suppressed the primary IgE and IgG antibody responses in the mouse, and markedly suppressed ongoing IgE antibody formation.

Animals↗
PubMed1982

DNA sequence of a gene encoding a BALB/c mouse Ld transplantation antigen.

The sequence of a gene, denoted 27.5, encoding a transplantation antigen for the BALB/c mouse has been determined. Gene transfer studies and comparison of the translated sequence with the partial amino acid sequence of the Ld transplantation antigen establish that gene 27.5 encodes an Ld polypeptide. A comparison of the gene 27.5 sequence with several complementary DNA sequences suggests that the BALB/c mouse may contain a number of closely related L-like genes. Gene 27.5 has eight exons that correlate with the structural domains of the transplantation antigen.

Amino Acid Sequence↗
PubMed1982

Heavy chain genes of rabbit IgG: isolation of a cDNA encoding gamma heavy chain and identification of two genomic C gamma genes.

A cDNA library was constructed by using rabbit spleen poly(A)+RNA as template, and from this library was isolated a cDNA clone, p2a2, that encodes 179 amino acids of the heavy chain of rabbit IgG. The nucleotide sequence of p2a2 showed that it encodes the COOH-terminal eight amino acids of the CH1 domain, the hinge region, the CH2 domain, and the NH2-terminal half of the CH3 domain of C gamma. Southern blot hybridization analysis of rabbit sperm DNA showed that two EcoRI fragments hybridized strongly with the C gamma cDNA. The p2a2 cDNA was used as a probe to isolate recombinant Charon 4A phage clones containing C gamma sequences from a genomic library of rabbit liver DNA. Two distinct DNA segments were identified by restriction mapping and hybridization analysis, suggesting that the haploid rabbit genome may contain two different C gamma genes.

Amino Acid Sequence↗
PubMed1981

A pseudogene homologous to mouse transplantation antigens: transplantation antigens are encoded by eight exons that correlate with protein domains.

We have isolated about 30 to 40 different BALB/c mouse sperm DNA genomic clones that hybridize to cDNA clones encoding proteins homologous to transplantation antigens. One of these clones (27.1) was selected for sequence because it was polymorphic in Southern blot analysis of the DNAs from BALB/c and CBA mice. A fragment of 5.7 kilobases of this clone was completely sequenced and found to contain a pseudogene whose sequence is highly homologous to the sequences of known transplantation antigens. Pseudogene 27.1 is split into eight exons that correlate with the structurally defined protein domains of transplantation antigens. Using Southern blot hybridization on the DNAs of different inbred mouse strains, we mapped the pseudogene to the Qa-2,3 region, a part of the Tla complex on chromosome 17 that is adjacent to the major histocompatibility complex. The Qa2,3 region encodes lymphoid differentiation antigens homologous to the transplantation antigens in size, in peptide map profiles and in their association with beta2-microglobulin. These mapping studies suggest that gene 27.1 may be a pseudogene for eigher a Qa antigen or an as yet undefined transplantation antigen. Accordingly, we may have isolate genes encoding lymphoid differentiation antigens of the Tla complex as well as those encoding transplantation antigens among the 30 to 40 different genomic clones isolated from our sperm library.

Base Sequence↗
PubMed1981

Expression of IgD may use both DNA rearrangement and RNA splicing mechanisms.

From a library of mouse sperm DNA, we have isolated two overlapping clones which contain the C(delta) gene. One of these clones also contains the C(mu) gene. The C(delta) gene is separated from the C(mu) membrane exons by approximately 2 kilobases (kb) of DAN. The C(delta) gene was identified by (a) hybridization to poly(A)(+)RNA prepared from the IgD-producing rat plasma cell tumor IR731, and (b) homology of a translated nucleotide sequence to the amino acid sequence of the human delta chain. The C(delta) gene spans 8 kb of DNA in the germ line. Plasmid subclones of the C(delta) gene were used as probes in Southern and RNA blot experiments. RNA blot analysis of cytoplasmic poly(A)(+)RNA from IR731 and a mu(+)delta(+) B-cell hybridoma revealed 1.6- and 2.7-kb delta mRNA species with different 3' ends, which presumably encode the secreted and membrane-bound forms, respectively, of the delta chain. Southern blot analysis of DNA from two mu(+)delta(+) lymphomas revealed that the C(delta) gene is in the germ-line configuration in each case. Restriction map analysis of C(mu) and C(delta) genomic clones isolated from a library of normal mu(+)delta(+) B-cell DNA also gave no evidence for DNA rearrangement in the region between the C(mu) and C(delta) genes. Taken together, these data suggest that IgD expression in mu(+)delta(+) B cells does not involve a V(H)-to-C(delta) DNA switch rearrangement. We propose that simultaneous expression of C(delta) and C(delta) with a single V(H) gene is mediated by two alternative routes of RNA processing of a primary nuclear transcript which contains the V(H), C(mu), and C(delta) genes. In contrast, analogous experiments with myeloma IR731 DNA revealed that the C(mu) gene has been deleted from the myeloma DNA and that the C(delta) gene has undergone DNA rearrangement, presumably including a switch recombination of the V(H) gene from the C(mu) to the C(delta) gene. These results indicate that two alternative mechanisms may be used in the expression of IgD molecules-RNA splicing in B cells and DNA rearrangement in plasma cells.

Animals↗
PubMed1979

Hydrogen transfer in catalysis by adenosylcobalamin-dependent diol dehydratase.

Studies [bachovchin, W. W., et al. (1978) Biochemistry 17, 2218] of the mechanism of inactivation of adenosylcobalamin-dependent diol dehydratase have led to the development of a general method to describe the kinetics of a reaction pathway containing a reservoir of mobile hydrogen. Analysis by this method of catalytic rate measurements for mixtures of 1,2-propanediol and 1,1-dideuterio-1,2-propanediol supports a mechanism involving an intermediate with three equivalent hydrogens, in which hydrogen transfer from this intermediate to product is the major rate-contributing step. Other results using tritium as a trace label [essenberg, M. K., et al. (1971) J. Am. Chem. Soc. 93, 1242] are considered in light of these deuterium isotope studies.

Cobamides↗
PubMed1978

Mechanism of action of adenosylcobalamin: hydrogen transfer in the inactivation of diol dehydratase by glycerol.

We have investigated the kinetic characteristics of the inactivation of the adenosylcobalamin-dependent enzyme propanediol dehydratase by glycerol, (RS)-1,1-dideuterioglycerol, (R)-1,1-dideuterioglycerol, and perdeuterioglycerol in the presence of 1,2-propanediol and 1,1-dideuterio-1,2-propanediol. The results imply that hydrogen (or deuterium) attached to C-1 of 1,2-propanediol participates in the inactivation process and contributes to the expression of a kinetic isotope effect on the rate of inactivation. The mechanism for this inactivation must involve the cofactor as an intermediate hydrogen carrier, presumably in the form of 5'-deoxyadenosine. Moreover, a mechanism involving a rate-determining transfer of hydrogen from an intermediate containing three equivalent hydrogens quantitatively accounts for all of the results. When diol dehydratase holoenzyme is inactivated by [1-3H]glycerol, 5'-deoxyadenosine which is enriched in tritium by a factor of 2.1 over that in glycerol can be isolated from the reaction mixture.

Cobamides↗
PubMed1977

Mechanism of action of adenosylcobalamin: glycerol and other substrate analogues as substrates and inactivators for propanediol dehydratase--kinetics, stereospecificity, and mechanism.

A number of vicinal diols were found to react with propanediol dehydratase, typically resulting in the conversion of enzyme-bound adenosylcobalamin to cob(II)alamin and formation of aldehyde or ketone derives from substrate. Moreover, all are capable of effecting the irreversible inactivation of the enzyme. The kinetics and mechanism of product formation and inactivation were investigated. Glycerol, found to be a very good substrate for diol dehydratase as well as a potent inactivator, atypically, did not induce cob(II)alamin formation to any detectable extent. With glycerol, the inactivation process was accompanied by conversion of enzyme-bound adenosylcobalamin to an alkyl or thiol cobalamin, probably by substitution of an amino acid chain near the active site for the 5'-deoxy-5'-adenosyl ligand on the cobalamin. The inactivation reaction with glycerol as the inactivator exhibits a deuterium isotope effect of 14, strongly implicating hydrogen transfer as an important step in the mechanism of inactivation. The isotope effect on the rate of product formation was found to be 8.0. Experiments with isotopically substituted glycerols indicate that diol dehydrase distinguishes between "R" and "S" binding conformations, the enzyme-(R)-glycerol complex being predominately responsible for the product-forming reaction, while the enzyme-(S)-glycerol complex results primarily in the activation reaction. Mechanistic implications are discussed. A method for removing enzyme-bound hydroxycobalamin that is nondestructive to the enzyme and a technique for measuring the binding constants of (R)- and (S)-1,2-propanediols are presented.

Adenosine↗
PubMedDate not supplied

Hydroxyurea for treatment of polycythemia secondary to right-to-left shunting patent ductus arteriosus in 4 dogs.

Four adult dogs with polycythemia secondary to reversed patent ductus arteriosus (rPDA) were treated with hydroxyurea, a myelosuppressive agent, for 6-22 months. Regardless of initial hematocrit, clinical signs attributed to the presence of polycythemia improved with hydroxyurea treatment. Chronic hydroxyurea therapy (40-50 mg/kg PO q48h) was well tolerated in this group of animals; mild, clinically silent thrombocytopenia and leukopenia were detected in some animals but resolved with decreased dosage or dose frequency. Chronic hydroxyurea therapy may provide an alternative to repeated phlebotomy for therapy of polycythemia secondary to rPDA.

Animals↗