PubMed Health⌕ Search

Biomedical subjects

C C Malone

Publications and source records attributed to C C Malone.

36 records · Page 2Linked to original sources

Epitopes on proteinase-3 recognized by antibodies from patients with Wegener's granulomatosis.

The 228 amino acid primary sequence of proteinase-3 (PR3) was studied for antigenic epitopes, which react with IgG Ab in sera of patients with Wegener's granulomatosis, by synthesizing overlapping 7 mers of PR3 linear sequence on pins. Main regions of linear sequence reactivity included GHEAQPH (at residues 4-10), QPHSRPY (8-14), TQEPTQQ (65-71), ATVQLPQ (108-114), QLPQQDQ (111-117), PVPHGTQ (118-124), RVGAHDP (132-138), FCRPHNI (154-160), PRRKAGI (165-171), FGDSGGP (173-179), and IDSFVIW (189-195). All of these regions were surface accessible and seemed to be on the outside of the molecule. By substituting a glycine or an alanine for each residue within each reactive epitope, we identified the arginine at 12, valine at 119, proline at 120, histidine at 121, arginine at 132, alanine at 135, histidine at 136, and glycine at 178 as major immunodominant single residues that contribute to antigenic determinants. Visualization of these reactive regions on a three-dimensional computer-generated carbon PR3 trace diagram showed that one aspect of the molecule on the inferolateral surface comprised most of the antigenic regions. Two peptides, ATVQLPQ and RVGAHDP, when preincubated with Wegener's granulomatosis sera, produced almost complete inhibition of Wegener's granulomatosis IgG Abs either binding to PR3 on the ELISA plate or by reacting with polymorphonuclear leukocyte azurophilic granules in immunofluorescence assays for cANCA. FGDSGGP (at residues 173-179), one epitope that was recognized by Wegener's patient sera Abs, included part of the active catalytic triad for PR3. Rabbit Abs against the PR3 peptides ATVQLPQ or RVGAHDP showed a cANCA cytoplasmic granular pattern of immunofluorescence staining when they were incubated with polymorphonuclear leukocytes. These findings indicate that it is possible to identify various antigenic sites on PR3 by using overlapping 7 mers of portions of the solvent, accessible linear sequence.

Amino Acid Sequence↗

Elevations of neutrophil proteinase 3 in serum of patients with Wegener's granulomatosis and polyarteritis nodosa.

OBJECTIVE: To determine serum levels of proteinase 3 (PR3) in normal subjects and patients with Wegener's granulomatosis (WG), polyarteritis nodosa (PAN), chronic renal failure, and systemic lupus erythematosus (SLE). METHODS: Serum levels of PR3 were measured by enzyme-linked immunosorbent assay employing a monospecific rabbit polyclonal antibody against PR3. RESULTS: Quantifiable levels of PR3 were detected in all serum samples examined, including those of normal subjects. Marked elevations of serum PR3, which decreased with treatment, were found in patients with active WG. Patients with PAN, SLE, and chronic renal failure also showed elevated levels of PR3. CONCLUSION: Quantitating serum PR3 may be useful in the management of patients with WG and other connective tissue diseases.

Antibodies, Antineutrophil Cytoplasmic↗

Changes in rheumatoid factor and monoclonal IgG antibody specificity after site-specific mutations in antigenic region of beta 2-microglobulin.

Antigenic epitopes on the SKDWSFY region (positions 57-63) of human beta 2-microglobulin (beta 2m) reacting in ELISA with polyclonal and monoclonal human IgM rheumatoid factors (RF) as well as with monoclonal mouse IgG anti-beta 2m antibodies were studied after site-specific mutation of single or double beta 2m amino acid residues. Single site-specific mutations at lysine 58 and serine 61 produced a major decrease (50-100%) in reactivity of polyclonal IgM RF with beta 2m. Mutations at serine 57, tryptophane 60, and phenylalanine 62 also induced substantial decrements (25-49%) in IgM RF reactivity. beta 2m mutants containing double amino acid mutations including one residue outside the SKDWSFY region along with four different mutations at tryptophane 60 also often showed marked decrements in IgM RF anti-beta 2m reactivity. Site-specific mutations at virtually all residues within the SKDWSFY beta 2m region produced a major decrease in reactivity of two of three monoclonal human IgM RF. Results with nine murine IgG anti-beta 2m mAbs often showed an entirely different profile. Site-specific mutation of aspartic acid at position 59 produced a 50-100% decrease in binding of nine mAbs. Serine at position 61 and tyrosine at 63 also appeared to represent important residues for antigenic determinants reacting with anti-beta 2m mAbs. Results of mapping discrete epitopes using glycine substitution within overlapping 7-mers of beta 2m linear sequence compared with site-specific mutation of single beta 2m residues were similar in many instances, but also often showed marked differences. A marked change in antigenic contribution of single amino acid residues to beta 2m antigenic epitopes frequently depended on what residues were mutated to. Our findings emphasize that single residues within a small seven amino acid, solvent-accessible antigenic stretch of primary beta 2m sequence vary considerably in their contribution to the reactive antigenic structures for IgM RF as well as monoclonal IgG antibodies.

Amino Acid Sequence↗

Expression of F4, 8.12, 3I, and 16/6 anti-DNA idiotype-related antigens on cationic human IgG myeloma proteins.

One hundred cationic isolated human IgG myeloma proteins were studied for expression of four anti-DNA idiotypic (Id) markers F4, 3I, 8.12, and 16/6. Forty-three of 100 myelomas showed the presence of at least one anti-DNA idiotype. Twenty-seven were F4 positive, 18 were 16/6 positive, 8 were 3I positive, and 7 were positive for 8.12. Two different anti-DNA idiotypic markers were found together on the same 14 myeloma proteins and 3 myelomas showed three different anti-DNA Ids. Anti-DNA activity was found on only 1 of 100 myelomas but not associated with presence of an anti-DNA Id. Ten myelomas showed anti-F(ab')2 activity and 6 of these also showed the presence of an anti-DNA Id marker. When myeloma proteins expressing anti-DNA Ids were compared in direct competition ELISAs with known Id-positive human IgG anti-DNA antibodies, much less inhibition was recorded in comparison to known human anti-DNA antibodies. Our findings indicate that human IgG myeloma proteins may show positive reactions with anti-DNA idiotypic antibodies but do not express the complete anti-DNA idiotypic antigenic complex.

Antibodies, Antinuclear↗

Rheumatoid-factor-reactive sites on CH2 established by analysis of overlapping peptides of primary sequence.

Polyclonal IgM rheumatoid factors (RF) from ten patients with rheumatoid arthritis (RA) isolated on IgG affinity columns were studied for their reactivity with overlapping 7-mer peptides representative of solvent accessible regions of the CH2 domains of IgG using a pin-ELISA assay. A panel of nine monoclonal RF from RA patients' B cells were studied in parallel. Four peptides SVFLFPP (239-245), KFNWYVD (274-280), NSTYRVVSV (297-305) and VLTVLHQNWL (305-314) reacted with most RF. Glycine substitution showed that tryptophanes at 277 and 313, tyrosine at 278, valines at 279 and 305, and leucine 314 represented important residues for RF reactivity. Assays using monoclonal IgM RF produced from RA synovial B cells or peripheral blood B cells frequently showed a restricted spectrum of reactivity for CH2 epitopes, which often were identical to those binding to polyclonal IgM RF. Combinations of synthetic 7-mer peptides representing RF-reactive CH2 or CH3 epitopes produced as much as 60-90% inhibition of RF binding to IgG when peptides were preincubated with RF in free solution before completion of the reaction of RF with IgG on the ELISA plate.

Amino Acid Sequence↗

Streptococcus pyogenes type M12 protein shows selective binding to some human immunoglobulin G3 myeloma proteins.

Purified, recombinant M12 protein from Streptococcus pyogenes CS24 has recently been demonstrated to bind human immunoglobulin G3 (IgG3). The binding site for IgG has been localized to an internal peptide encoded by a PvuII fragment of the gene emm12. We have investigated the ability of an isolated recombinant M12 protein consisting of the peptide encoded by the PvuII fragment to bind various monoclonal human IgG3 myeloma proteins representing a number of both Caucasian and Oriental IgG3 Gm(allotypic) phenotypes. Of nine Caucasian IgG3 myeloma proteins, only two bound strongly to the recombinant M12 protein in enzyme-linked immunosorbent assays. The allotypic phenotypes of the reactive proteins were IgG3m(b+)(g-) and IgG3m(b-)(g+). No binding was seen for seven IgG3 myeloma proteins of Oriental origin with G3m(st+)(u-)(b+)(g-), G3m(st-)(u+)(b+)(g-), G3m(st-)(u+)(b-)(g+), and G3m(st-)(u-)(b-)(g+) phenotypes. The binding of human IgG3 to M12 protein seems to be related to features other than its Gm allotypic markers. Selective reactivity of IgG3 myeloma proteins with M12 protein may provide another way to subclassify human IgG3 molecules. The biological significance of the selective reactivity is not known.

Animals↗

Studies of protein A and herpes simplex virus-1 induced Fc gamma-binding specificities. Different binding patterns for IgG3 from Caucasian and Oriental subjects.

Herpes simplex virus type 1 (HSV-1) expresses a receptor that binds the Fc portion of IgG. This HSV-1 Fc gamma-binding protein is, like protein A of Staphylococcus aureus, known to bind human IgG1, IgG2 and IgG4 but not IgG3 subclasses. However, IgG3 with the allotype Gm(s+)(t+), prominent in the Oriental population, reacts with protein A. This prompted us to investigate the reactivity of Oriental IgG3 monoclonal myeloma proteins of various allotypes with the HSV-1 Fc gamma-binding protein. Of seven Oriental IgG3 myeloma proteins with allotypes Gm(s+)(t+)(u-)(b+)(g-), Gm(s-)(t-)(u+)(b+)(g-) and Gm(s-)(t-)(u+)(b-)(g+), all reacted with the HSV-1 Fc gamma-binding protein. This was in contrast to negative reactions obtained with three IgG3 myeloma proteins of Caucasian origin with Gm(b+)(g-) or Gm(b-)(g+) phenotypes. The same binding pattern, i.e. binding of IgG3 of Oriental but not of Caucasian origin, was found with protein A. The binding of the monoclonal Oriental IgG3 proteins was again independent of the G3m phenotype. These findings support the concept that the HSV-1 Fc gamma-binding protein A have a similar binding site on the IgG molecule. All monoclonal IgG3 proteins derived from Oriental subjects with or without histidine at position 435 bound to HSV Fc gamma-binding protein. This suggests that Oriental IgG3 myeloma proteins with Gm(s-)(t-) phenotypes have additional critical amino acid residue substitutions important for HSV Fc gamma binding different from those already known.

Asian People↗

Rheumatoid factors from patients with rheumatoid arthritis react with tryptophan 60 and 95, lysine 58, and arginine 97, on human beta 2-microglobulin.

OBJECTIVE: To define precise epitopes on human beta 2-microglobulin (beta 2m) reacting with polyclonal IgM rheumatoid factors (RF) from patients with rheumatoid arthritis (RA). METHODS: Ten polyclonal RF were tested for their human beta 2m epitope-binding specificities using the entire 99-amino acid sequence synthesized as overlapping 7-mers in an enzyme-linked immunosorbent assay. Glycine substitution for each residue within RF-reacting linear regions was employed to define major reactive sites. RESULTS AND CONCLUSION: Major beta 2m residues contributing to RF reactivity were tryptophans at positions 60 and 95, lysine at 58, and arginine at position 97.

Amino Acid Sequence↗

Conformational dependency of human IgG heavy chain-associated Gm allotypes.

Human IgG allotypic markers Gm(a)[Glm(1)], Gm(x)[Glm(2)]; Gm(f)[Glm(4)], Gm(b)[G3m(5) and (11)] and Gm(g)[G3m(21)] were studied after chemical modification of IgG histidines by diethylpyrocarbonate, tyrosines by N-acetylimidazole and lysines by formaldehyde and sodium borohydride. Degrees of substitution were estimated by trinitrobenzenesulfonic acid assay. IgG of known Gm phenotype isolated from serum of hyperimmune anti-tetanus toxoid donors was studied. Histidyl modification resulted in virtually complete loss of Gm(a) and Gm(g) antigenicity but preservation of Gm(x), Gm(b) and Gm(f). Reconstitution of the histidyl residues using hydroxylamine resulted in virtually complete restoration of Gm(a) and Gm(g) antigenicity. Histidine modification resulted in no significant decrease in ELISA anti-tetanus antibody activity. Alteration of tyrosyl residues using N-acetylimidazole considerably diminished Gm(a) and Gm(f) expression. This effect was reversed by hydroxylamine treatment. Moreover, chemical alteration of tyrosyl residues produced a complete loss of Gm(g) antigenicity which was only partially restored after deacylation. A urinary H chain fragment containing the VH region directly linked to C gamma 3 which contained the Gm(a) specific and Gm(x) specific amino acid residues was positive for Gm(a) but negative for Gm(x). Another urinary H chain fragment containing only the C gamma 3 domain was negative for both Gm(a) and (x). These findings indicate that Gm allotypic markers may depend on conformational determinants in which strongest expression for Gm(a) and (x) depends on structures expressed by C gamma 3 linked to C gamma 2 domains. Although RFs react with the region encompassing the C gamma 2-C gamma 3 interface, Gm-specificities of such reactions are affected allosterically through single or double amino acid substitutions at a relatively distant site.

Amino Acid Sequence↗

Rheumatoid factors from patients with rheumatoid arthritis react with Des-Lys58-beta 2m, modified beta 2-microglobulin.

Ten polyclonal IgM rheumatoid factor (RF) preparations, affinity-purified from IgG columns, from patients with rheumatoid arthritis were studied for their ELISA reactivity with native beta 2m in parallel with Lys58-cleaved beta 2m and Des-Lys58-beta 2m, the latter representing cleavage products of the native molecule present in some pathologic human sera. Most RF showed positive reactions with the native form of beta 2m but reduced reactivity for the cleaved forms of beta 2m. Reactions between cleaved beta 2m and RF, in solution, were demonstrated by inhibition of RF binding to native beta 2m by preincubation with a range of concentrations of Des-Lys58-beta 2m. By contrast, eight of nine murine MoAbs to human beta 2m showed approximately equivalent binding to native beta 2m, Lys58-cleaved beta 2m, and Des-Lys58-beta 2m. Reactions between individual human RF and the altered forms of beta 2m (Lys58-cleaved beta 2m and Des-Lys58-beta 2m) appeared to parallel the previously determined beta 2m single amino acid specificities, in that RF showing strong reactivity with Lysine 58 also showed a significant diminished reactivity with the Des-Lys58-beta 2m lacking the critical lysine residue. The present studies demonstrate that while human RF react with Lys58-cleaved beta 2m or Des-Lys58-beta 2m, preferential reactivity is observed for native unaltered beta 2m.

Amino Acid Sequence↗

Monoclonal IgM rheumatoid factors generated from synovial B cells of rheumatoid arthritis patients react with beta 2-microglobulin. Monoclonal RF react with beta 2m.

Four of 15 monoclonal human IgM rheumatoid factors (RF) derived from synovial B cells of patients with rheumatoid arthritis showed positive ELISA reactions with human beta 2-microglobulin. These findings were different from those previously noted using IgM RF derived from monoclonal Waldenstrom's paraproteins or the IgM components of mixed cryoglobulins, and resembled the anti-beta 2 microglobulin specificity of polyclonal IgM RF from patients with rheumatoid arthritis. Reactions of monoclonal IgM synovial RF with overlapping 7-mers of beta 2m sequence indicated major regions of positive reactivity at positions 57-64 and 89-95 which were maintained in the presence of high salt (300 mM NaCl) conditions. Glycine substitution of each residue within RF-reactive beta 2m regions indicated that tryptophanes at position 60 and 95, lysine at 58, phenylalanine at 62, valine at 93 and arginine at 97 constituted important single amino acids for the reactive epitopes. These findings indicate that clonally restricted human IgM RF derived from diseased tissues of patients with RA show anti-beta 2m reactivity similar to polyclonal RF from the same patients. This particular fine specificity is not present in monoclonal RF derived from patients with Waldenstrom's or mixed cryoglobulins showing anti-gamma-globulin activity.

Amino Acid Sequence↗

Antigenic epitopes on beta 2-microglobulin reacting with monoclonal antibodies.

Monoclonal antibody-reactive antigenic regions on the 99 amino acid sequence of human beta 2-microglobulin were examined by using nine anti-beta 2 m monoclonal antibodies (mAbs) and Geysen pins coated with overlapping heptamers derived from the primary sequence. Reactive linear sequences were then restudied with glycine substitution for each successive residue. All nine mAbs showed a similar profile, with peak reactivity at residues 57-63 SKDWSFY and 87-97 LSQPKIVKWDR. Glycine substitution established the tryptophans at positions 60 and 95 as well as the lysines at 58, 91, and 94 as immunodominant residues important for mAb reactivity. Other adjacent residues (serine 57, phenylalanine 62, tyrosine 63, isoleucine 92, valine 93, and proline 90) also make important contributions to beta 2 m antigenic epitopes. Rabbit antipeptide antibodies against the beta 2 m peptides SKDWSFY and LSQPKIVKWDR produced quantitative precipitin curves with beta 2 m in solution. Addition of iodine 125-labeled beta 2 m to antipeptide antibody followed by protein A precipitation and sodium dodecyl sulfate gel electrophoresis with autoradiography showed that labeled beta 2 m reacted in solution phase with anti-SKDWSFY or anti-LSQPKIVKWDR antibody. These findings establish residues 57-63 and 87-97 in human beta 2 m as major reactive antigenic sites for monoclonal as well as polyclonal anti-beta 2 m antibodies.

Amino Acid Sequence↗

Heteroclitic polyclonal and monoclonal anti-Gm(a) and anti-Gm(g) human rheumatoid factors react with epitopes induced in Gm(a-), Gm(g-) IgG by interaction with antigen or by nonspecific aggregation. A possible mechanism for the in vivo generation of rheumatoid factors.

Heteroclitic rheumatoid factors (RF) are specific for allotypic determinants, e.g., Gm(a) or Gm(g) on allogeneic, but not autologous IgG. All polyclonal RF we isolated from nine rheumatoid arthritis patients with circulating Gm(a-), (b+), (g-), (f+) IgG displayed dual heteroclitic activity for the Gm(a) and Gm(g) allotypes, as shown by using appropriate RBC agglutination assays and affinity columns bearing Gm(a+) or Gm(g+) IgG. To investigate possible mechanisms underlying the in vivo generation of heteroclitic RF, we tested the ability of nonspecifically and immune-specifically aggregated Gm(a-), (g-) IgG to function as targets for RF from Gm(a-), (g-) patients with rheumatoid arthritis. Heat aggregation (63 degrees C for 20 min) or binding to Ag (as in tetanus toxoid-antitetanus toxoid complexes) induced a "functional" Gm(a+) and/or (g+) phenotype in Gm(a-), (g-) IgG from five healthy subjects and five rheumatoid patients, as suggested by the ability of these altered IgG to function as efficient targets for six heteroclitic RF in direct binding and competitive inhibition experiments. That heterocliticity and dual Gm(a), Gm(g) specificity can be features of a single antibody molecule was formally demonstrated by analysis of a monoclonal RF (IgM mAb 61) generated from a Gm(a-), (g-) rheumatoid patient. RF mAb 61 displayed a high affinity (Kd, 10(-7) M) for IgG Fc fragment of Gm(a+) and (g+) IgG or aggregated autologous Gm(a-), (g-) IgG but did not bind to native autologous IgG. To investigate the molecular basis of the acquired Gm(a) phenotype, PBMC from five Gm(a-) patients with rheumatoid arthritis and two Gm(a-) normal subjects arthritis and two Gm(a-) normal subjects were cultured in vitro after activation with PWM. In most instances, these PBMC produced IgG that behaved as Gm(a+) in sensitive ELISA. Application of the polymerase chain reaction (PCR), using probes specific for the nucleotide sequence coding for the Gm(a) tetrapeptide, to the amplification of DNA from the in vitro-stimulated Gm(a-) normals or rheumatoid patients' PBMC provided no evidence for Gm(a) nucleotide sequences. The present data suggest that acquisition of the Gm(a) determinant by Gm(a-) IgG may result from subtle changes in the CH2-CH3 RF-binding region. Such changes would occur when Gm(a) IgG are complexed with Ag or nonspecifically altered, thereby providing a possible explanation for the induction of heteroclitic RF in Gm(a-) rheumatoid arthritis patients.

Antibodies, Monoclonal↗

Rheumatoid factors from patients with rheumatoid arthritis react with beta 2-microglobulin.

IgM rheumatoid factors (RF) from 18 sera of rheumatoid arthritis (RA) patients isolated from monomeric IgG affinity columns showed strongly positive ELISA reactions with human beta 2-microglobulin (beta 2m), as well as with recombinant beta 2m. When the same RA sera were adsorbed to beta 2m-Sepharose affinity columns, eluted material showed predominant IgM anti-Fc of IgG and anti-beta 2m reactivity. Inhibition reactions with "RF" obtained from IgG affinity columns showed slightly higher reactivity of RF for Fc over beta 2m; however, when RF from the same RA serum had been adsorbed to and eluted from beta 2m affinity columns, beta 2m showed greater inhibition than Fc for RF reacting with either beta 2m or Fc on ELISA plates. Thus two overlapping populations of RF were identified in RA sera showing reactivity with both beta 2m and Fc of IgG. When RF were isolated from IgG columns, affinity was slightly higher for Fc than beta 2m. Conversely, RF eluted from beta 2m Sepharose reacted slightly more with beta 2 m than Fc. Trypsin digests of a polyclonal RA IgM RF showed no beta 2m reactivity in Fc mu 5 fragments. Fab mu RF retained slight anti-Fc IgG but no residual anti-beta 2m activity. Monoclonal human IgM, IgG, or IgA RF either from mixed cryoglobulins or EBV-stimulated RA lymphoid cell lines showed negative or occasional weakly positive anti-beta 2m activity. Overlapping 7-mer peptide ELISA analysis of the entire 99-amino acid sequence of beta 2m showed a major RF-reactive linear hydrophilic sequence at positions 56-60 which included a 3-amino acid exact homology to positions 401, 403, and 404 of the C gamma 3 domain. A peptide encompassing this sequence produced 90% inhibition of RF binding to whole beta 2m. Substitution of neutral glycines for each amino acid throughout the reactive epitope at positions 56-66 indicated that lysine at position 58 aspartic acid at 59, and tryptophane at 60 represented major portions of the RF-reactive epitope. These findings indicate that human RF derived from patients with RA react with other epitopes besides those present on IgG Fc, including epitopes on human beta 2m. For many years serum RF3 found in patients with RA have been regarded as premier examples of autoantibodies to autologous IgG.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗

Studies of antibody to herpes simplex virus Fc gamma-binding protein gE in patients with rheumatoid arthritis, juvenile rheumatoid arthritis and normal controls.

IgG antibody to gE, the Fc gamma-binding herpes simplex 1 (HSV-1) viral glycoprotein, was studied in 49 rheumatoid arthritis (RA) patients and 43 normal controls. Antibody to gD, another important HSV-1 antigen, was assayed in parallel. No difference between RA patients and normal controls was found in levels of anti-gE antibody measured by reactivity of IgG F(ab')2 fragments reacting with gE coated to ELISA plates. No difference in anti-gD antibody was recorded between normals and patients with RA. Levels of IgG anti-IgE antibody did not correlate with quantitative elevations of serum rheumatoid factor (RF) in RA patients. When IgG anti-gE and anti-gD were assayed in 20 patients with juvenile rheumatoid arthritis and 22 children controls, no significant differences were noted. However, when individual RFs from patients with RA were tested for reactivity against a panel of affinity-isolated F(ab')2 antibodies to gE, some evidence for individual autospecificity was obtained. Four of 20 monoclonal IgM RFs produced from RA patients' B cells showed marked elevations of reactivity with some RA patients' F(ab')2 antibodies to gE. All four of the monoclonal RFs showing this specificity were derived from RA synovial tissue B cells. These findings may provide support for the concept that some RFs in patients with RA show individual specificity for internal image determinants of IgG antibodies to viral Fc gamma-binding proteins.

Adult↗

Des-Lys58-beta 2m and native beta 2m in rheumatoid arthritis serum and synovial fluid.

OBJECTIVE: Levels of beta 2-microglobulin and modified beta 2-microglobulin (Des-Lys58-beta 2m) were measured in serum and synovial fluids from patients with rheumatoid arthritis (RA) and other inflammatory joint disorders using rabbit antisera prepared against the beta 2m peptide VEHSDLSFS encompassing residues 49-57 and absorbed with the C-terminal beta 2m peptide (87-97) LSQPKIVKWDR: These antisera which did not react with native beta 2m were employed to quantitate Des-Lys58-beta 2m in serum and SF. Native beta 2m was measured using a direct ELISA method. RESULTS: Removal of serum rheumatoid factor by adsorption to monomeric IgG columns did not change serum levels of beta 2m or Des-Lys58-beta 2m. Native beta 2m was found in all of 20 RA sera, but only rarely in SLE sera. No serum beta 2m was found in 20 patients with ankylosing spondylitis or 25 normal controls. Significant elevations of Des-Lys58-beta 2m were found in 80% of 21 SF from RA patients and in 43% of 41 SF from other subjects with various forms of inflammatory arthritis. In RA and other disorders such as gout or pseudogout, levels of Des-Lys58-beta 2m were higher in synovial fluid than in serum during an acute episode of synovitis. Both native beta 2m and Des-Lys58-beta 2m showed minimal neutrophil and T cell chemotactic activity. CONCLUSION: Des-Lys58-beta 2m present in many inflammatory SF may contribute to the inflammatory reaction in many forms of connective tissue disease by its known amplification of T cell cytotoxicity.

Amino Acid Sequence↗

Benign monoclonal gammopathy with IgG anti-DNA, anti-Sm and anti-F(ab')2 activity.

OBJECTIVE: To study anti-DNA idiotypic markers and anti-DNA activity in human monoclonal immunoglobulin proteins. METHODS: Seventy human IgG M-components intentionally selected for cationic electrophoretic characteristics were studied for F4 and 31 anti-DNA idiotypic markers and anti-DNA as well as anti-F(ab')2 antibody activity. RESULTS: Eight of 70 M-components showed significant anti-DNA activity. In two both anti-DNA and anti-F(ab')2 activity occurred together. One IgG-2 kappa M-component showed extremely high anti-ds DNA, anti-Sm, anti-F(ab')2 and anti-Sm/ RNP ELISA activity. Cross inhibition studies showed that each reactive antigen inhibited the other. N-terminal V-region sequencing showed the VH3, VK3 subgroup. Anti-idiotypic rabbit antibody produced against this M-component showed strong reactivity with affinity purified IgG anti-DNA and anti-F(ab')2 from most SLE patients and normal subjects. CONCLUSION: Monoclonal human immunoglobulins may contain multiple autoantibody specificities including anti-DNA; anti-Sm, anti-Sm/RNP, and anti-F(ab')2. Many antibodies with these specificities share common V-region antigens. Such relationships could contribute to idiotypic immune regulation and control.

Aged↗