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W H Reeves

Publications and source records attributed to W H Reeves.

85 records · Page 5Linked to original sources
PubMed1986

Interaction between anti-DNA and anti-DNA-binding protein autoantibodies in cryoglobulins from sera of patients with systemic lupus erythematosus.

We have previously shown that sera from some patients with SLE and related disorders contain autoantibodies to a DNA-binding protein complex designated p70/p80. The present study shows that anti-p70/p80 autoantibodies are frequently accompanied by anti-DNA antibodies and cryoglobulins. When the cryoglobulins were isolated, they were found to be specifically enriched in both anti-p70/p80 and anti-DNA activities. The anti-p70/p80 and anti-DNA antibodies were found to be distinct populations of autoantibodies rather than a single crossreactive species, since they could be separated from one another by chromatography on DNA-cellulose. Certain human anti-DNA mAbs could inhibit the binding of autoimmune polyclonal anti-p70/p80 antibodies to p70/p80, suggesting that anti-DNA antibodies might also associate with the variable regions of some anti-p70/p80 antibodies in the cryoglobulins. Binding of one murine anti-p70/p80 mAb (111-12) also was inhibited by certain human anti-DNA mAbs, but the binding of another murine mAb (162-11) to a different epitope of p70/p80 was not. These studies suggest that certain anti-DNA antibodies may interact with the variable regions of a population of anti-p70/p80 antibodies. The cryoglobulins found in the sera containing both anti-p70/p80 and anti-DNA antibodies may represent immune complexes consisting, in part, of idiotype and antiidiotype.

Antibodies, Antinuclear↗
PubMed1986

Human autoantibodies reactive with the signal-recognition particle.

We describe autoantibodies reactive with the signal-recognition particle (SRP) in serum of a patient with polymyositis. The serum specifically immunoprecipitated the SRP from human erythroleukemia (K562) cell extracts. Analysis of immunoblots revealed that the serum contained autoantibodies specific for the 54-kDa protein of the SRP but had little or no reactivity with its other five proteins. Indirect immunofluorescence of human laryngeal carcinoma (HEp-2) cells confirmed that the ribonucleoprotein immunoprecipitated by this serum is found mainly in the cytoplasm. This autoimmune serum may be useful for studying the function of the 54-kDa subunit of the SRP in binding to signal sequences or in interacting with other components of the translational machinery.

Antibody Specificity↗
PubMed1985

Use of monoclonal antibodies for the characterization of novel DNA-binding proteins recognized by human autoimmune sera.

Autoantibodies to a DNA-binding heterodimer consisting of 70,000 and 80,000 dalton subunits were identified in 30-50% of human autoimmune sera from patients with systemic lupus erythematosus (SLE), mixed connective tissue disease (MCTD), and scleroderma. Three murine monoclonal antibodies (mAb) against the heterodimer were produced in BALB/c mice by immunizing with isolated human B cell nuclei. By immunofluorescence, the mAb and autoimmune sera demonstrated both speckled nucleoplasmic staining and diffuse nucleolar staining in all human cell types examined. The nucleoplasmic staining was sensitive to DNase but not RNase pretreatment, while the nucleolar staining was sensitive to RNase but not DNase pretreatment. Biochemical characterization of the 70,000 and 80,000 dalton proteins using the mAb indicated that two forms of the antigen, with different mobilities on sucrose gradients, are present in human B cells. A 10 S form consists of the physically associated 70,000 and 80,000 dalton proteins, while a larger, 10-20 S form probably represents the same two proteins bound to DNA. Binding of the proteins to nucleolar RNA could not be confirmed in biochemical studies. These studies indicate that non-histone, DNA-binding proteins may be more frequently recognized by autoantibodies in SLE, MCTD, and scleroderma than has been previously recognized. Along with previous studies on RNA-binding proteins such as Sm, RNP, Ro, and La, the present findings suggest that nucleic acid-binding proteins, as a class, may be particularly frequent targets of autoimmunity in SLE and related disorders.

Animals↗
PubMed1985

Temporal shifts from Sm to ribonucleoprotein reactivity in systemic lupus erythematosus.

The Sm and RNP autoantibodies, found in the sera of many patients who have connective tissue diseases, recognize determinants on small nuclear ribonucleoprotein particles (snRNP). Numerous techniques have been used to distinguish between the subsets of snRNP proteins recognized by these two antibody systems. Using protein and snRNP immunoprecipitation, as well as a competitive enzyme-linked immunosorbent assay, antibodies in the sera of Sm patients have been observed to include variable quantities of RNP-like reactivity. To analyze changes in these autoantibodies, 2 patients with anti-Sm antibodies were followed temporally. The autoantibodies in the sera of both patients underwent shifts from predominant Sm reactivity to predominant RNP reactivity. In 1 patient the shift occurred gradually over several years, while in the other the shift occurred within 8 weeks.

Adult↗
PubMed1985

Small nuclear ribonucleoprotein particle assembly in vivo: demonstration of a 6S RNA-free core precursor and posttranslational modification.

The in vivo synthesis and assembly of human small nuclear ribonucleoproteins (snRNPs) have been studied using pulse/chase analysis. Antibodies derived from patients with systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD) recognize distinguishable subsets of pulse-labeled snRNP peptides. These antibodies were used to immunoprecipitate sucrose gradient fractionated pulse-labeled and pulse/chased snRNP proteins. The results indicate that assembly of the U RNA-containing snRNPs is a multistep process involving prior assembly of an RNA-free 6S core particle. This precursor contains snRNP peptides D, E, F, and G, which are common to all the different U RNA-containing particles. Furthermore, a posttranslational modification of one of the U1 snRNP-specific peptides has been observed, and the kinetics of this process indicates that the modification occurs after particle assembly. Functional and structural implications of a protein core for snRNP particles are discussed.

Antibodies↗
PubMed1985

Autoimmune sera reactive with Sm antigen contain high levels of RNP-like antibodies.

Ribonucleoprotein particles containing Sm antigen were separated from particles containing both Sm and RNP antigens by ion-exchange chromatography to study the recognition of these antigens by autoimmune sera. By using the separated antigens, anti-Sm and/or anti-RNP antibodies were detected in approximately 60% of sera from systemic lupus erythematosus patients by both enzyme-linked immunosorbent assay and immunoprecipitation of radiolabeled antigens followed by analysis on sodium dodecyl sulfate-polyacrylamide gels. These antibodies were detected in 30% of the same sera using the standard passive hemagglutination technique. Competition experiments demonstrated that all of the sera tested that contained anti-Sm antibodies also had anti-RNP-like reactivity. This latter reactivity usually represented 80% or more of the total Sm and RNP binding activity in lupus sera. The binding to RNP-like determinants by several of the sera was uniquely resistant to treatment of the antigen with snake venom exonuclease. These studies indicate that humoral immunity against Sm and RNP antigens in systemic lupus erythematosus is directed primarily against a single type of ribonucleoprotein particle in which the two antigens are physically associated. The specific binding to a single type of ribonucleoprotein particle suggests that this particle may be especially immunogenic and that it might play an important role in induction of the humoral immune response to Sm and RNP.

Antigens↗
PubMed1985

Concept formation, problem-solving and the right hemisphere.

The pioneering work of Sperry in the 1960s presented a challenge to the traditional view that the right hemisphere is functionally limited to the processing of nonlinguistic, visual-spatial information on a perceptual level. Yet, the recent position of Gazzaniga (1983) is in support of the traditional view. This investigation tested further the hypothesis of right hemisphere concept formation and problem-solving. Right hemispherically strong children were compared with normal controls in terms of linguistic and nonlinguistic information processing. The results were in support of the right hemisphere as capable of cognitive processes beyond the level of simple nonverbal perceptual tasks.

Adolescent↗
PubMed1984

Pulse labeling of small nuclear ribonucleoproteins in vivo reveals distinct patterns of antigen recognition by human autoimmune antibodies.

Antibodies directed against small nuclear ribonucleoprotein ( snRNP ) particles are found in the Sm and RNP autoimmune sera from numerous patients with systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD). These two reactivities differ in disease distribution as well as antigen specificity. Although sera from both of these autoimmune syndromes contain snRNP reactive antibodies, distinction in antigen binding specificity have been difficult to define because of the particulate nature of the snRNP antigen. To overcome this problem, while retaining the antigen in a native state, cells were pulse-labeled with [35S]methionine for 8 min to generate radioactive snRNP proteins in forms reflecting incomplete de novo particle assembly. Immunoprecipitation of snRNP antigen prepared in this manner revealed clearly distinct patterns of Sm and RNP immunorecognition . While Sm sera precipitated all eight labeled snRNP proteins, RNP antibodies precipitated only two of the eight. However, a brief pulse followed by periods of cold chase demonstrated that RNP sera can eventually coprecipitate all components of the complete particle. In addition to antibodies to the other six snRNP peptides, all Sm sera tested have been found to contain the RNP-like reactivity with snRNP proteins A and C. RNP reactivity with these two components is of particular interest because these proteins are unique in the metabolism of snRNPs. Defining and distinguishing the precise peptides recognized by Sm and RNP antibodies has helped to clarify the biochemical basis of the standard laboratory tests for these antigen reactivities.

Antigen-Antibody Complex↗
PubMed1983

Synthesis and assembly of human small nuclear ribonucleoproteins generated by cell-free translation.

Cell-free translation of human poly(A)+ RNA was carried out to generate and analyze the protein constituents of small nuclear ribonucleoprotein (snRNP) particles. The snRNP proteins were identified by immunoprecipitation with sera from patients with systemic lupus erythematosus. Size fractionation of mRNA prior to translation revealed that these snBNP proteins are all encoded by separate messages. One of the proteins (the A protein, molecular weight 32,000) was seen to lose antigenicity upon RNase treatment either when extracted from cells or when generated in vitro. RNase treatment of immunoprecipitated snRNPs released the A protein in an electrophoretically pure form. Analysis of snRNPs translated in vitro revealed the presence of unassembled and assembled particles as determined by sucrose density gradient sedimentation. Post-translational assembly of snRNPs involving both RNA-protein binding (as revealed by A protein antigenicity) and associations of other snRNP proteins occurred in the in vitro system employed here. In addition, the presence of unassembled snRNP proteins permitted the determination of the precise antigen peptides recognized by Sm and RNP autoimmune sera. It was observed that Sm sera are capable of recognizing each of the eight snRNP proteins, whereas RNP sera recognize only two of the eight.

Autoantibodies↗
PubMed1983

Right cerebral hemispheric function: behavioral correlates.

Studies of cerebral asymmetry generally support verbal-analytic functions on the left hemisphere and nonverbal, integrative functions on the right. The hypothesis of this investigation was that right hemisphere functions have greater significance for adaptive behaviors, i.e., verbal-analytic abilities are not specifically related to environmental adjustment or coping skills. Right hemispherically strong children were compared with normal controls along six behavioral parameters. The results supported environmental awareness and adaptive skills as related more to the right hemisphere than the left. It is suggested that self-monitoring of behavior and possibly affective integration appear to be more related to the processing of spatial, sequential information on the right hemisphere than verbal-analytic functions on the left.

Adolescent↗
PubMed1980

Assembly of the glomerular filtration surface. Differentiation of anionic sites in glomerular capillaries of newborn rat kidney.

Glomerular development was studied in the newborn rat kidney by electron microscopy and cytochemistry. Glomerular structure at different developmental stages was related to the permeability properties of its components and to the differentiation of anionic sites in the glomerular basement membrane (GBM) and on endothelial and epithelia cell surfaces. Cationic probes (cationized ferritin, ruthenium red, colloidal iron) were used to determine the time of appearance and distribution of anionic sites, and digestion with specific enzymes (neuraminidase, heparinase, chondroitinases, hyaluronidases) was used to determine their nature. Native (anionic) ferritin was used to investigate glomerular permeability. The main findings were: (a) The first endothelial fenestrae (which appear before the GBM is fully assembled) possess transient, negatively charged diaphragms that bind cationized ferritin and are impermeable to native ferritin. (b). Two types of glycosaminoglycan particles can be identified by staining with ruthenium red. Large (30-nm) granules are seen only in the cleft of the S-shaped body at the time of mesenchymal migration into the renal vesicle. They consist of hyaluronic acid and possibly also chondroitin sulfate. Smaller (10-15-nm) particles are seen in the earliest endothelial and epithelial basement membranes (S-shaped body stage), become concentrated in the laminae rarae after fusion of these two membranes to form the GBM, and contain heparan sulfate. They are assumed to be precursors of the heparan sulfate-rich granules present in the mature GBM. (c) Distinctive sialic acid-rich, and sialic acid-poor plasmalemmal domains have been delineated on both the epithelial and endothelial cell surfaces. (d) The appearance of sialoglycoproteins on the epithelial cell surface concides with the development of foot processes and filtration slits. (e) Initially the GBM is loosely organized and quite permeable to native ferritin ;it becomes increasinly impermeable to ferritin as the lamina densa becomes more compact. (f) The number of endothelial fenestrae and open epithelial slits increases as the GBM matures and becomes organized into an effective barrier to the passage of native ferritin.

Animals↗