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Biomedical subjects

J M Stuart

Publications and source records attributed to J M Stuart.

At least 127 records · Page 7Linked to original sources

Failure of calcitonin to inhibit collagen-induced arthritis in rats.

Previous reports have demonstrated suppressive effects of salmon calcitonin (SCT) on inflammation and immune reactions. A rat model of arthritis induced by immunization with type II collagen was studied in an attempt to demonstrate antirheumatic and immunosuppressive actions of SCT. No inhibition of arthritis or of specific immune responses to collagen was found.

Animals↗

The role of collagen autoimmunity in animal models and human diseases.

Although immune reactions to collagen have been described in several diseases, the pathophysiologic consequences of collagen autoimmunity remain obscure. We have recently described an animal model of polyarthritis which can be induced in susceptible rats or mice by immunization with native type II collagen. Arthritis develops in animals which have high levels of both cellular and humoral immunity to collagen. In rats, arthritis can be passively transferred with purified IgG antinative type II collagen antibodies. There is circumstantial evidence that antibodies are also important for the initiation of arthritis in susceptible mice. Circulating immune complexes do not appear to be involved and we believe the arthritis is caused by binding of antibodies to autologous collagen. There are a number of similarities between collagen-induced arthritis and human rheumatoid arthritis (RA). Many histopathologic changes are similar including synovitis which progresses to pannus formation, development of marginal erosions and eventual cartilage destruction. Both diseases are associated with collagen autoimmunity which appears to be genetically linked to the major histocompatibility locus. However, there are also significant differences. In particular, the antibody reactivity usually found in RA is primarily directed against covalent structural determinants on collagen and not against the conformation-dependent determinants on type II collagen critical to the development of collagen-induced arthritis. Immunity to collagen has also been described in other animal models of disease and in other human diseases but its relevance to their pathophysiology is unknown. By further characterizing the specific reactions involved including the nature of the immune response, its specificity and the genetic factors important in the host; insight may be gained into the role of collagen autoimmunity in human disease. While significant progress has been made in all of these areas during the last several years, much remains to be learned before the relevance of collagen autoimmunity to any human disease is established.

Animals↗

Nature and specificity of the immune response to collagen in type II collagen-induced arthritis in mice.

To determine the role of collagen-immunity in the development of collagen-induced arthritis, DBA/1 mice were immunized with type II collagen and observed for the development of polyarthritis. 96% of the mice immunized with native type II collagen developed inflammatory arthritis between 4 and 5 wk after primary immunization. Immunization with denatured type II collagen in exactly the same manner was not effective in inducing arthritis. Cell-mediated immunity in arthritic mice was assessed by measuring [3H]thymidine incorporation by mononuclear cells cultured in the presence of collagen. The maximal proliferative response to collagen occurred at 2 wk after immunization. Equally good incorporation of label occurred when cells were cultured with native or denatured type II collagen or type I collagen. The cellular response of nonarthritic mice immunized with denatured collagen was indistinguishable from that seen in arthritic mice. Humoral immunity was assessed by an ELISA assay for antibodies to collagen. The immunoglobulin M (IgM) response peaked at 2 wk and the IgG response at 5 wk after immunization. Antisera from arthritic mice immunized with native type II collagen were relatively specific for conformational determinants on the native type II molecule although some reactivity with denatured collagen was noted. Antisera from nonarthritic mice immunized with denatured collagen primarily recognized covalent structural determinants. It was concluded that native type II collagen was essential for the induction of arthritis and that an antibody response specific for native type II collagen may be important for the development of arthritis.

Animals↗

Type II collagen-induced arthritis in mice. I. Major histocompatibility complex (I region) linkage and antibody correlates.

A model of arthritis was established by the injection of type II collagen into mice. Only mice bearing the H-2q haplotype were susceptible to the disease. Susceptibility was further mapped by the use of recombinant strains on the Iq locus. Type II collagen arthritis was observed in the (resistant X susceptible) F1 cross. Mice strains were designated high, intermediate, or low responders with respect to the anti-type II antibody levels measured by radioimmunoassay. Arthritis-susceptible strains were all classified as high antibody responders. The clinical and histological appearance of type II collagen arthritis in the mouse indicates that it may be a good animal model for the investigation of various immunogenetic traits in rheumatoid arthritis.

Animals↗

Auricular chondritis in rats. An experimental model of relapsing polychondritis induced with type II collagen.

Outbred Wistar rats immunized with native type II collagen developed ear lesions resembling those of human relapsing chondritis. As in human disease, these lesions were characterized by intense chondritis, positive immunofluorescence reactions to IgG and C3, and circulating IgG reactive with native type II collagen. Furthermore, electron-dense deposits were seen near the surface of chondrocytes and corresponded with deposits of IgG and C3. These observations suggest a causal relation between humoral immunity to type II collagen and auricular chondritis in the rat and support the hypothesis than human relapsing polychondritis is an autoimmune disease mediated by immunity to type II collagen.

Animals↗

Effect of cyclophosphamide, hydrocortisone and levamisole on collagen-induced arthritis in rats.

The immune response of rats to type II collagen was modified by pretreating the rats with levamisole, hydrocortisone, or cyclophosphamide. Rats were observed for the development of collagen-induced arthritis and were bled serially for the determination of antibody levels to type II collagen. Levamisole had a slight but not significant potentiating effect with arthritis developing earlier, whereas hydrocortisone and cyclophosphamide significantly depressed the incidence of arthritis; cyclophosphamide also delayed its onset. Antibody levels measured by radioimmunoassay paralleled the clinical course of arthritis.

Animals↗

Type IV collagens' isolation and characterization of 7S collagen from human kidney, liver and lung.

7S collagens were isolated after bacterial collagenase treatment of basement membrane material prepared from the pepsin digest of human kidney, liver and lung. The 7S collagens were purified by combination of molecular sieve and ion exchange chromatography. 7S collagen from each of these sources showed similar amino acid composition, electrophoretic patterns of reduced and unreduced samples. Antibodies raised against human placental 7S collagen in rabbits completely cross-reacted with the 7S collagen preparation obtained from kidney, liver and lung in enzyme-immunoassays. Since 7S collagen in known to be a major cross-linked segment of type IV collagens, the data indicate that collagenous proteins of basement membranes are organized in similar networks in a variety of organs.

Amino Acids↗

Cell-mediated immunity to collagen and collagen alpha chains in rheumatoid arthritis and other rheumatic diseases.

Peripheral blood mononuclear cells from patients with rheumatoid arthritis, gout, ankylosing spondylitis and degenerative joint disease were cultured in the presence of native types I, II and III collagens and alpha chains from each of these types of collagen. The culture supernatant fluids were harvested and assayed for lymphocyte-derived chemotatic factor for monocytes. Reactions to one or more of the native collagens was found in 50 per cent (10 of 20) of the patients with rheumatoid arthritis, 20 per cent (two of 10) of the patients with gout and ankylosing spondylitis but in none of the 10 patients with degenerative joint disease or in normal subjects. Reaction to one or more alpha chains was found in 90 per cent (18 of 20) of the patients with rheumatoid arthritis, 60 per cent (six of 10) of the patients with gout, 50 per cent (five of 10) of the patients with ankylosing spondylitis, 30 per cent (three of 10) of the patients with degenerative joint disease and in 10 per cent of the normal subjects (one of 10). All the reactions were quantiatively stronger in patients with rheumatoid arthritis. These results indicate that patients with rheumatoid arthritis have cell-mediated immunity to homologous native and denatured collagens but that the reaction is not specific for rheumatoid arthritis. Some patients with gout, ankylosing spondylitis and degenerative joint disease also have low levels of immunity.

Adult↗

Collagen-induced polyarthritis in rats: a study of native type II collagen for adjuvant activity.

Collagen-induced polyarthritis in rats is a new experimental model that shares clinical and histologic features with adjuvant arthritis. To determine whether collagen-induced arthritis is a form of adjuvant disease and to further exclude contamination of collagen with an adjuvant substance, native type II collagen was studied for adjuvant properties. IgM and IgG PFC activity and PBMC [3H]TdR incorporation were studied in rats after injection with TNP-OA combined with IFA, IFA and CII, or CFA. In general, humoral and CMI responses to TNP-OA were lower in rats injected with IFA/CII compared with those with IFA; the presence of CII during primary immunization failed to significantly enhance PFC activity to TNP after a boost. CFA-injected rats gave maximal values in both studies. Mice pretreated with BII in the absence of oil gave PFC responses below control after sensitization with SRC. Furthermore, CII was unable to replace mycobacteria in the induction of EAE in rats and was devoid of mitogenic or polyclonal stimulatory properties. It is concluded that collagen-induced arthritis is a distinct entity from adjuvant arthritis and is dependent upon the unique immunogenicity of type II collagen in rats rather than upon an adjuvant effect.

Animals↗

Collagen-induced arthritis in rats. Comparison of vitreous and cartilage-derived collagens.

An oil emulsion of purified type II collagen from bovine articular cartilage when injected intradermally into rats induced an inflammatory polyarthritis in 4 of 12 animals. When similarly injected, collagen purified from bonve vitreous induced arthritis in 6 of 12 animals. Studies of humoral and cell-mediated immunity to both collagen preparations demonstrated complete cross-reactivity. It is concluded that vitreous collagen shares the arthritogenic property of cartilage-derived type II collagen and that collagen from the two sources is indistinguishable in arthritogenic and immunologic properties.

Animals↗

Collagen-induced arthritis in rats. Evaluation of early immunologic events.

When rats were injected intradermally with an oil emulsion of native type II collagen, they developed an inflammatory polyarthritis. The incidence and severity of arthritis increased as the amount of collagen injected was increased. Rats 4 1/2 weeks old were the most susceptible to the development of arthritis, whereas weanling and older animals were relatively resistant. There was no difference in incidence between males and females. Mononuclear cells from peripheral blood, lymph nodes, and spleen were cultured with type II collagen and responded maximally to a collagen concentration of 25 microgram/ml. The earliest detectable response was in peripheral blood mononuclear cell cultures obtained 6 to 8 days after immunization. The response of lymph node and spleen cells tended to lag behind that of peripheral blood cells at the earlier time intervals. Antibodies were detected in sera by hemagglutination at 8 days postimmunization. Quantitation of IgM and IgG antibodies by radioimmunoassay showed good correlation with hemagglutination titers and increased binding of collagen by both classes of antibody in arthritic as compared to nonarthritic animals. It is clear that the development of both humoral and cellular immunity to type II collagen is associated with the development of arthritis and may be important in the pathogenesis of this disease.

Age Factors↗

Pustular blastomycosis.

A 53-year-old Negro man had North American blastomycosis with acute onset of widespread pustular eruptions. Several tests suggested that the patient might have had a deficiency of delayed hypersensitivity.

Blastomycosis↗

Evidence for cell-mediated immunity to collagen in progressive systemic sclerosis.

Peripheral blood leukocytes from 12 patients with progressive systemic sclerosis and from 12 normal subjects were cultured in the presence of human skin collagen, lathryritic chick skin collagen, and alpha-chains from chick skin collagen. Leukocytes from 11 of the patients produced a factor chemotactic for human monocytes when cultured with the collagen preparations. The one patient whose cells did not respond to the collagen preparations also failed to respond to other common antigens and was apparently anergic. In addition, lymphocytes from three of the patients were found to transform when cultured with the collagen preparations. These responses were significantly different from the response of leukocytes from normal control subjects. The data suggest that patients with progressive systemic sclerosis may have cellular immunity to collagen.

Adolescent↗

Type II collagen-induced autoimmune otospongiosis. A preliminary report.

Otospongiosis-like lesions were induced in rats by immunizing them with native type II collagen. Immunized rats had antibody responses specific for native type II collagen and developed otospongiosis-like lesions. The spongiotic lesion was characterized by numerous osteocytes and osteoblasts in the vascular spaces and by dark staining probably due to the chemical alteration of ground substances. Bone resorption and new bone formation were clearly visible. Immunofluorescence studies demonstrated deposition of immunoglobulin and complement on the bone matrix and wall within the area of spongiosis. An antibody-mediated etiopathogenesis was suspected.

Animals↗

Type II collagen-induced autoimmune sensorineural hearing loss and vestibular dysfunction in rats.

Autoimmune sensorineural hearing loss was induced in rats by immunizing them with native bovine type II collagen. Type I and denatured type II collagen, administered by an identical immunization procedure, would not induce disease. Evidence of sensorineural hearing loss was obtained by measuring the brainstem evoked potential and by observing histopathologic changes consisting of cochlear nerve degeneration and perineural vasculitis in affected animals. Immunized animals had high levels of antibodies to native type II collagen.

Animals↗