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Biomedical subjects

W J Koopman

Publications and source records attributed to W J Koopman.

At least 127 records · Page 7Linked to original sources

Exquisite sensitivity of dendritic cells to ultraviolet radiation and temperature changes.

Recent data suggest that dendritic cells (DC) are the critical passenger leukocytes in allograft rejection. Moreover, previous studies suggest that ultraviolet radiation (UVR) abrogates many in vivo and in vitro immune responses in which DC function as potent accessory cells (AC); however, the mechanism(s) underlying the suppressive effect of UVR on these responses is unclear. To address this mechanism, the hypothesis was tested that loss of DC viability (hence function) accounts for the suppressive effect of UVR on these responses. To this end, in vitro effects of UVR on murine splenic DC viability were addressed using two types of UVR (ultraviolet B [UVB] and ultraviolet C [UVC]) over a UVR dose range of 0-864 J/m2. DC viability was exquisitely sensitive to UVR when compared with other AC populations and UVC was 4-fold more effective in decreasing DC viability than UVB when doses of equal energy were compared. It was found that both UVR types induced marked decreases in DC viability beginning 4-6 hr post-UVR-treatment, that UVR- and non-UVR-induced death were temperature-dependent, and that decreases in DC viability induced by UVR were compatible with interphase death. Our findings indicate that DC are sensitive to temperature changes and exquisitely sensitive to UVR, and suggest that UVR-induced abrogation of murine immune responses is likely attributable to UVR-induced DC death.

Animals↗

Molecular genetic studies of rheumatoid arthritis.

Bam HI DR-beta and DQ-beta restriction fragment length polymorphisms (RFLPs) were found with increased frequency in white persons with seropositive rheumatoid arthritis as compared with control subjects. DR-beta 4.8-, 5.2-, and 7.0-kilobase (kb) RFLPs were observed in 86.5 percent of rheumatoid arthritis patients and in 56 percent of control subjects (p = 0.001, relative risk [RR] = 5.0). The 6.0-kb RFLP was present in 79 percent of rheumatoid arthritis patients and 32 percent of control subjects (p = 0.0002, RR = 8.0). The 4.8-, 5.2-, and 7.0-kb RFLPs correlated with DR4, -7, -9, and -w53 phenotypes and the 6.0-kb RFLP correlated only with DR4. Thus, these RFLPs do not appear to be disease-specific. A DQ-beta 3.2-kb RFLP was found in 63.5 percent of rheumatoid arthritis patients and in 38.0 percent of control subjects (p = 0.01, RR = 2.8). This fragment was frequently found in persons expressing DR1 and DQw1 phenotypes. Probes consisting of the first exon of the DR-beta-I and DR-beta-IV genes, respectively, only hybridized with the 5.2- and 6.0-kb RFLPs. These data suggest that more than one gene within the major histocompatibility complex contributes to susceptibility to seropositive rheumatoid arthritis in white persons.

Arthritis, Rheumatoid↗

Restriction fragment length polymorphism analysis in ankylosing spondylitis.

We utilized the technique of restriction fragment length polymorphism (RFLP) analysis in order to examine class I major histocompatibility complex genes in 52 Alabama ankylosing spondylitis patients and 107 local control subjects. A 9.2-kilobase PvuII RFLP was identified using the class I-specific B7 cDNA probe pDP001 that was closely associated with ankylosing spondylitis, most specifically with peripheral joint (including shoulder and hip) involvement. This fragment is associated with human leukocyte antigen A3 and A9 alleles, and segregation analysis in 11 multiplex families showed the RFLP to frequently segregate independently of B27 haplotypes. Two more recent studies have not confirmed the association of the 9.2-kilobase PvuII RFLP with ankylosing spondylitis per se, believed to be due to clinical and possibly genetic differences between the patient groups studied. These data strongly suggest at least one other major histocompatibility complex class I gene to be operative in predisposition to or modification of ankylosing spondylitis.

Deoxyribonucleases, Type II Site-Specific↗

Recombinant murine IL-5 induces high rate IgA synthesis in cycling IgA-positive Peyer's patch B cells.

Recent studies have shown that purified IL-5 from T cell lines and clones enhances IgA synthesis in LPS-triggered splenic B cell cultures, and that this effect is augmented by IL-4. In this study we have examined the ability of rIL-5 and rIL-4 to support spontaneous Ig synthesis in normal Peyer's patch (PP) B cell cultures. The rIL-4 supported proliferation of the HT-2 and in vivo adapted BCL-1 cell lines, increased Ia expression on normal spleen B cells, co-stimulated splenic B cell proliferation in the presence of anti-mu and enhanced IgG1 synthesis in LPS triggered splenic B cell cultures. The rIL-5 supported BCL-1 proliferation, co-stimulated splenic B cell proliferation in the presence of dextran sulfate, and increased IgA synthesis in LPS-stimulated splenic B cell cultures. Markedly enhanced IgA responses occurred in PP B cell, but not splenic B cell cultures supplemented with rIL-5 in the absence of an added B cell trigger. However, rIL-4 alone did not enhance IgA synthesis or increase the IgA synthesis of PP B cell cultures stimulated with rIL-5. The rIL-5 receptive PP B cells were present in the blast cell subpopulation, inasmuch as a low density fraction isolated on Percoll gradients accounted for the enhanced IgA synthesis. Further, cell cycle analysis of whole PP B cells using propidium iodide in conjunction with staining for surface B220, demonstrated that approximately 12 to 16% of the B cells were in the S and G2/M stages of cell cycle, the remainder being in Go + G1. The surface IgM+ B cells were predominantly in Go + G1, whereas the sIgA+ B cell subpopulation was enriched for cells in the S and G2/M compartments. The PP B cell subset responsible for enhanced IgA synthesis in the presence of rIL-5 was sIgA-positive because FACS-depletion of the sIgA+ B cells resulted in the total loss of rIL-5 enhanced IgA synthesis. Further, when PP B cells were enriched for sIgA+ B cells by cell sorting, these cells responded to rIL-5 with increased IgA synthesis in a dose-dependent manner. When the actual numbers of IgA secreting cells were assessed in PP B cell cultures with supplemental rIL-5, no significant increase in total IgA-producing cells was noted when compared with B cells cultured without rIL-5.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

Incidence of three cross-reactive idiotypes on human rheumatoid factor paraproteins.

The basis for rheumatoid factor (RF) production in autoimmune or lymphoproliferative diseases cannot be understood without defining the molecular factors that dictate RF structure and specificity. Recently three different mAb (6B6.6, 17.109, and G6) have been developed that define cross-reactive idiotypes (CRI) on intact L or H chains of human monoclonal RF cryoglobulins. However, the true incidence of these CRI among RF and their relationship to each other have not been delineated. In the present experiments, a panel of 163 randomly selected IgM paraproteins was evaluated for the expression of the two kappa L chain CRI, 6B6.6 and 17.109, and the H chain CRI, G6. Among the paraproteins with kappa L chains, 14% expressed the 17.109 CRI, and 9% expressed the 6B6.6 CRI. Both ELISA and Western immunoblotting experiments showed that the two L chain CRI were mutually exclusive. Anti-IgG activity was documented in 22 of the IgM-kappa paraproteins, among which mAb 6B6.6 reacted with 7 (32%) and mAb 17.109 with 6 (27%). Both CRI were expressed exclusively by L chains within the kappaIII variable gene subgroup. Although 17.109 CRI+ paraproteins had kappaIIIb L chains, none of the 6B6.6 CRI+ paraproteins possessed L chains with this kappa sub-subgroup specific Ag. The G6 CRI was found predominantly among RF paraproteins and was frequently yet not exclusively associated with the 17.109 CRI+ L chains. Additional experiments were performed on a panel of normal adult human sera and documented the presence of 6B6.6 and 17.109 CRI on a small percentage (0.1 to 2.0%) of IgM from most individuals. These data indicate that 1) the mAb 6B6.6 and 17.109 identify two major and distinct CRI among IgM-RF paraproteins, 2) both CRI are associated exclusively with kappaIII L chains, 3) kappaIIIb and kappaIII non-b L chains are equally prevalent among IgM-RF, 4) the G6 H chain CRI is frequently associated with 17.109 CRI+ L chains, but not with 6B6.6 CRI+ L chains, and 5) although the ability to make 6B6.6 and 17.109 CRI+ kappa L chains is common in humans, these CRI are present in low concentrations in normal IgM.

Adolescent↗

Abnormal glycosylation of serum IgG from patients with chronic inflammatory diseases.

Results of carbohydrate analysis of serum IgG from patients with rheumatoid arthritis (RA) confirmed an earlier report that IgG from patients with RA is galactosylated to a lesser extent than IgG from healthy individuals. In contrast to the previous report, we found that the content of galactose in IgG from controls and RA patients was negatively correlated with age (P = 0.026 and P = 0.010, respectively). In RA patients, the IgG content of galactose was also negatively correlated with the pain index (P less than 0.05) and was lower in the presence of rheumatoid factor (P less than 0.05). No correlation was found between the galactose deficiency of IgG from RA patients and sex, race, duration of disease, packed red blood cell volume, radiographic grade, disability index, extraarticular manifestations, articular erosions, or treatment with steroids. Furthermore, no correlation was found between the galactose content of IgG and serum levels of IgM rheumatoid factor or the ability of IgG to bind IgM rheumatoid factor in vitro. Significant galactose deficiency was also detected in IgG from patients with systemic lupus erythematosus and Crohn's disease, which suggests that the defect in the galactosylation of IgG is a feature common to a variety of chronic inflammatory diseases. The biologic significance of this observation remains unclear.

Adult↗

Occurrence of polymeric IgA1 rheumatoid factor in the acquired immune deficiency syndrome.

The sera of 34 acquired immune deficiency syndrome (AIDS) patients and 20 healthy male homosexuals were examined for the presence of elevated levels of IgA and IgM rheumatoid factor (RF) and compared with results obtained with sera from 23 healthy laboratory volunteers. IgA RF levels were elevated (greater than 3 standard deviation units) in 9 of 34 (26%) patients with AIDS as compared to the panel of laboratory controls. Levels of IgM RF did not differ significantly in the AIDS patients and in the controls. There were no differences in levels of either IgA RF or IgM RF when the homosexual controls were compared with the laboratory volunteers. Sucrose-gradient ultracentrifugation experiments and assays using monoclonal reagents specific for IgA subclasses indicated that the IgA RF was predominantly of the polymeric configuration and restricted to the IgA1 subclass, respectively. Polyethylene glycol (PEG) precipitates of serum enriched for circulating immune complexes (CIC) were also assayed for the presence of IgA RF and IgM RF. Although levels of IgA RF in serum and in PEG precipitates did not correlate with levels of IgA- or IgA/IgG-containing CIC in AIDS patients, levels of IgA RF in both serum and CIC-enriched material were significantly elevated in the AIDS population when compared with the control panel. In contrast, levels of IgM RF in both serum and CIC-enriched material were low and not significantly different from those in healthy controls. These results indicate that both IgA-containing CIC and IgA RF occur in many AIDS patients and raise the possibility that IgA RF may contribute significantly to the formation of immune complexes in this disease.

Acquired Immunodeficiency Syndrome↗

Clinically significant valvular heart disease in systemic lupus erythematosus.

PURPOSE: Clinically significant valvular heart disease due to systemic lupus erythematosus (SLE) has generally been considered rare, and Libman-Sacks endocarditis has been thought to be predominantly an autopsy finding. With the declining prevalence of rheumatic heart disease, however, the spectrum of valvular heart disease is changing. We retrospectively analyzed our experience with SLE between 1975 and 1987 for the presence of hemodynamically significant valvular heart disease. PATIENTS AND METHODS: An existing data base of 421 patients with SLE was selected for review. Patients were selected for inclusion in the study if they met four or more of the criteria of the American Rheumatism Association for SLE, they had clinically significant valvular heart disease, and tissue from the involved valve was available for review. The etiology of the valve lesion was determined by assessment of the clinical history, chart review, gross morphology, and valve histology. RESULTS: Of 14 cases with pathologic material available for review, six had anatomic features of SLE valvular heart disease such as verrucous vegetations or valvulitis with necrosis and vasculitis. Two of these patients underwent successful valve replacements and four died from complications of their valve disease. CONCLUSION: We suggest that significant morbidity and mortality may result from SLE valvular heart disease in about 1 to 2 percent of SLE patients and that the pathogenetic mechanisms underlying valve dysfunction in SLE patients are multifactorial.

Adolescent↗

Autoimmunity to collagen in adult periodontal disease.

Although it has been documented that exogenous antigens of microbial origin are involved in the induction of the local inflammatory responses in human adult periodontitis (AP), endogenous antigens may contribute to the chronicity of this common disease. In this study, we used the enzyme-linked immunospot (ELISPOT) test to enumerate antibody-secreting cells to human collagen Types I-VI by cells isolated from the gingivae and peripheral blood of AP patients. Analyses of dissociated cells from gingivae of 39 AP patients revealed the presence of high numbers of cells that secrete antibodies to Type I collagen, and to a lesser extent, Type III. Although the majority of such cells produced specific antibodies of the IgG class, IgA- and IgM- anti-collagen -secreting cells were also detected. When compared to the total antibody-producing cells, the numbers of cells forming specific antibodies to collagen Type I were surprisingly high. In contrast, anti-collagen antibody-producing cells were rarely detected in the peripheral blood of patients with adult periodontal disease and only low levels of anti-collagen antibodies were present in the serum. The finding of local production of anti-collagen antibodies in AP suggests that autoimmunity may contribute to the pathogenesis of this common disease.

Antibody-Producing Cells↗

Ultrastructural study of Sjögren's syndrome-like disease in MRL/l mice.

Salivary glands of autoimmune MRL/l mice were examined ultrastructurally and by immunoelectron microscopy to further characterize the Sjögren's syndrome-like disease in these animals. Major salivary glands from 12 female and 7 male MRL/l, two female MRL/n, and one female BALB/c mice were examined by electron microscopy and the glands from 4 female MRL/l mice were subjected to immunoelectron microscopy in order to detect Lyt-1 and Lyt-2 positive lymphoid cells. Mononuclear cell infiltrates were not seen in the salivary gland from the BALB mouse and occurred rarely in glands of MRL/n mice. However, in MRL/l mice, numerous lymphoid cells were present and acinar cells displayed low cytoplasmic density, cytoplasmic vacuolization and cellular lysis. Lymphoid cells were predominantly Lyt-1 positive although some Lyt-2 positive cells were observed. These results suggest that the MRL/l mouse represents a useful model for the study of the pathogenesis of Sjögren's syndrome in man.

Animals↗

Occurrence of a mu-chain idiotope in two human monoclonal RF which also share a kappa-chain idiotope.

Evidence was obtained for the presence of a common idiotypic determinant on the mu chains of two human monoclonal IgM proteins (COR and LEW) with rheumatoid factor (RF) activity using three mouse monoclonal antibodies which were prepared by immunization with the isolated heavy chains. The idiotope was detected on the intact proteins as well as the isolated mu-chains, but not on four other monoclonal IgM RF proteins, a monoclonal IgA RF protein, and two monoclonal IgM proteins without RF activity. Previous studies have shown that COR and LEW IgM RF also share a prominent kappa-chain idiotope. The parallel occurrence of mu- and kappa-chain idiotopes on monoclonal IgM RF proteins from unrelated patients suggests that there may be combinatorial restrictions in the pairing of RF heavy and light chain variable regions.

Antibodies, Monoclonal↗

The MRL-lpr/lpr mouse. A model for the study of rheumatoid arthritis.

Autoimmune MRL-lpr/lpr mice develop a spontaneous destructive arthropathy sharing some features with rheumatoid arthritis including synovial cell proliferation, pannus formation, rheumatoid nodule-like lesions and circulating rheumatoid factors. Rheumatoid factors elaborated by MRL-lpr/lpr mice exhibit binding characteristics similar to those found in the sera of patients with rheumatoid arthritis; however, these autoantibodies do not appear to be essential for the induction of arthritis in MRL-lpr/lpr mice. Molecular studies, indicating that VH genes from several VH families are capable of encoding these rheumatoid factors, argue against the existence of unique "autoantibody genes" in the germline of MRL-lpr/lpr mice. Although the mechanisms underlying cartilage injury in MRL-lpr/lpr mice have not been elucidated, available evidence suggests that invading synovial cells play an important role. Delineation of the cellular and molecular mechanisms responsible for articular destruction in MRL-lpr/lpr mice may provide important insights concerning the pathogenesis of rheumatoid arthritis.

Animals↗

Features of renal vasculitis in autoimmune MRL lpr/lpr mice: phenotypes and functional properties of infiltrating cells.

MRL lpr/lpr (MRL/1) mice spontaneously develop a widespread renal vasculitis. The majority of the cells in vasculitic lesions are bright Ly-1, L3T4 and la-positive in contrast to the cells found in lymph nodes and spleens of the old MRL/1 mice. However, despite differences in phenotypical patterns, B and T cells from arteritic lesions do not differ from mononuclear cells (MNC) eluted from MRL/1 lymph nodes with regard to the frequency of IgG secreting cells and the proliferative responses to Concanavalin A (Con A). Co-culture experiments with congeneic MRL+/+ (MRL/n) spleen cells indicate that the poor response to Con A of the MNC eluted from vasculitic lesions is, unlike the case of lymph node MNC, due to suppressive action of vasculitic cells on the indicator cell population. Further support for the activation status of infiltrating MHC in kidney vasculitic lesions, expressed by high in vivo uptake of 3H-thymidine, was obtained by autoradiography performed on frozen sections. The observed differences in phenotypic patterns and functional features between lymph node MNC and infiltrating vasculitic MNC indicate that different immune mechanisms may be responsible for the development of lymphadenopathy and vasculopathy, respectively in MRL/1 mouse.

Animals↗

Etiopathogenesis of rheumatoid arthritis-like disease in MRL/1 mice: II. Ultrastructural basis of joint destruction.

MRL/1 mice develop a spontaneous hindlimb arthropathy characterized by proliferation of synovial cells and by dissociation between early destruction of articular tissue and the presence of inflammatory cell infiltration. To characterize the ultrastructural details of the synovial cells of these mice, knee joints from MRL/1, MRL/n, and BALB/c mice were examined by light and electron microscopy. Since the proliferating synovial cells of MRL/1 mice resemble the previously described proliferative synovial cells seen in histopathologic specimens from early rheumatoid arthritis, further study of these cells may provide new insights into the pathogenesis of early joint tissue destruction in human rheumatic disease.

Animals↗

Specificity of monoclonal anti-Z-DNA antibodies from unimmunized MRL/Mp-lpr/lpr mice.

Antibodies reactive with left-handed Z-DNA arise spontaneously in the sera of patients with SLE and rheumatoid arthritis and in autoimmune MRL mice. However, the precise specificity of these autoantibodies has not been established. In this report, we have characterized four monoclonal anti-Z-DNA antibodies from unimmunized MRL/Mp-lpr/lpr mice that do not cross-react with B-DNA and can discriminate between different types of left-handed helices. Two of the monoclonal antibodies (Za and Zi) behaved similarly in that they bound to two forms of Z-DNA (Br-poly(dG-dC).poly(dG-dC) and AAF-poly(dG-dC).poly(dG-dC) but not to two other Z-form DNA (poly(dG-5BrdC).poly(dG-5BrdC) or poly(dG-5MedC).poly(dG-5MedC)). Neither antibody (Za or Zi) bound significantly to B-DNA or to denatured DNA. A third antibody (Ze) exhibited similar binding characteristics for the Z-DNA preparations, but also recognized denatured DNA. In contrast, a fourth antibody (3-7.3) bound preferentially to poly(dG-5BrC).poly(dG-5BrdC) in Z conformation. These results provide the first evidence for anti-Z-DNA autoantibodies in autoimmune mice that do not cross-react with native or denatured DNA and indicate that these antibodies exhibit considerable heterogeneity in their fine binding specificity.

Animals↗

Streptococcal serotype carbohydrate represents a novel class of type 2 antigen which is T-independent.

Our studies reported here, fully characterize two unique type 2 antigens trinitrophenol (TNP)-M1 serotype carbohydrates (TNP-M1 g and TNP-M1 c) derived from streptococci, which fail to induce antibody responses in xid or neonatal mouse splenic cultures. These antigens generate brisk responses in normal spleen and Peyer's patch cell cultures of xid mice, all of which suggest that responses are elicited in the Lyb-3+, 5+ B subpopulation. The antibody responses to TNP-M1 g (and TNP-M1 c) are not dependent upon T cells. Furthermore, TNP-M1 carbohydrates induce anti-TNP plaque-forming (PFC) responses in cultures of small, resting splenic B cell populations without an added T cell requirement. Thus two categories of type 2 antigens are distinguished, one which requires T cells or derived factors, e.g., TNP-Ficoll, and a second TNP-carbohydrate antigen TNP-M1 that does not. Studies of the mitogenic and polyclonal B cell activation properties of M1 carbohydrates indicated that B cell proliferation is induced in both xid (Lyb-3-, 5-) and normal (Lyb-3-, 5- and Lyb-3+, 5+) splenic B cell subpopulations, but that differentiation to IgM synthesis fails to occur in the Lyb-3-, 5- B cell subpopulation. Thus M1 carbohydrates are unique probes that allow the selective induction of proliferation and differentiation of mature B cells that are presumably Lyb-3+, 5+. Because the M1 serotype carbohydrates induce polyclonal IgM synthesis and antigen-specific responses in only the mature B cell population in the absence of T cells, whereas TNP-Ficoll and other type 2 antigens require T cells or their derived factors, the Lyb-3+, 5+ B cell subpopulation may consist of a T cell-dependent and a T cell-independent compartment for responses to different carbohydrate type 2 antigens.

Animals↗

Acute cryoglobulinemic renal failure after intravenous infusion of gamma globulin.

A 39-year-old woman had mixed IgM/IgG cryoglobulinemia, but was later found to have a lymphoma that produced an IgM kappa paraprotein with rheumatoid factor activity. With intermittent chlorambucil and prednisone therapy, the lymphoma was controlled for five years and she had no evidence of cryoglobulinemia. Because of the presence of intractable pulmonary infection and hypogammaglobulinemia G, she was given an intravenous infusion of gamma globulin. Within 72 hours, renal failure and a sustained decrease in serum concentrations of IgM and IgG began concurrently. A kidney biopsy specimen obtained five days after the infusion showed hyaline "thrombi" in numerous glomerular capillaries and glomerular necrosis, consistent with acute, severe mixed cryoglobulinemic nephropathy. Immunostaining showed strong positivity for IgM, IgG, and light chains in glomerular capillary lumina and subendothelial sites; immunostaining with a monoclonal antiidiotypic antibody specific for the patient's paraprotein established the presence of the rheumatoid factor paraprotein in the deposits. These observations strongly suggest that complexes consisting of IgM kappa rheumatoid factor, IgG, and complement initiated the renal damage. Therefore, demonstrable serum rheumatoid factor activity in patients with B cell neoplasms should be considered a contraindication to the administration of intravenous gamma globulin.

Acute Kidney Injury↗

Analysis of paraprotein transport into the saliva by using anti-idiotype antibodies.

To determine the extent of clonal involvement of the secretory immune system and the origin of salivary immunoglobulins (Ig) in monoclonal gammopathy patients, saliva and serum samples were collected from five affected individuals (two IgA myelomas, one IgG myeloma, one IgG benign monoclonal gammopathy, and one IgM lymphoma) and were assayed for the presence of monoclonal Ig. Purified polyclonal or monoclonal anti-idiotype (Id) antibodies were prepared against each of the isolated serum paraproteins. In all five individuals, the patient saliva samples inhibited the binding of 125I-labeled homologous Ig to the corresponding anti-Id antibodies, but normal saliva did not. The concentration of Id in patients' saliva varied from 1 to 400 micrograms/ml; i.e., 0.004 to 1.0% of the corresponding serum values. Saliva of a lymphoma patient whose IgM kappa protein exhibited rheumatoid factor (RF) activity also contained RF. The salivary Id-bearing molecules were found to have the same Ig isotype as the serum paraproteins. The myeloma IgA represented a minor component (0.4 and 3.9%) of the total salivary IgA. The salivary IgA myeloma proteins were associated at least in part with secretory component, but the salivary IgG paraproteins were not. In an IgA myeloma patient, a minority (17%) of the IgA+ plasma cells found in the lacrymal gland biopsy specimen were Id+, whereas the great majority (98%) of bone marrow IgA plasma cells were Id+. The results suggest active transport rather than passive transudation of myeloma IgA into the patients' saliva, and the integrity of the secretory immune system was not compromised by the neoplastic process.

Biological Transport↗