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The inner ear is capable of rapidly mounting an immune response that can ultimately lead to cochlear degeneration and permanent hearing loss. The role of the endolymphatic sac in this immune process is not clear. In order to investigate the cytokine expression of cells within the endolymphatic sac, a secondary inner ear immune response to keyhole limpet hemocyanin (KLH) was created in mice. The animals were sacrificed 3-48 h and 7 days following initiation of the immune response. The cochleas and endolymphatic sacs were assayed by immunocytochemistry for IL-1beta, TNFalpha, and IL-6. Three hours after KLH challenge of the scala tympani, the perisaccular tissue of the endolymphatic sac contained more inflammatory cells than the scala tympani or endolymphatic sac lumen. Only a few of these cells, however, expressed the proinflammatory cytokines IL-1beta and TNFalpha between 3 and 12 h after KLH injection. On the other hand, TNFalpha, which plays an important role in the cochlear secondary immune response, was expressed in cells in the endolymphatic sac lumen. The maximum percentage of cells expressing TNFalpha was seen later than in the scala tympani. Animals treated with systemic injection of the TNF blocker, etanercept, showed a reduction in the number of cells in the endolymphatic sac lumen. It is concluded that the cells in the endolymphatic sac lumen contribute to the amplification of the adaptive immune response by expressing TNFalpha, while the infiltration of cells into the perisaccular connective tissue is part of the nonspecific, innate, cochlear immune response.

Hypothesis: Etanercept will be able to reduce the inflammation and hearing loss associated with experimentally induced labyrinthitis., Background: Inner ear immune responses cause hearing loss that may be reversible with pharmacologic treatment. Etanercept, tumor necrosis factor receptor blocker, was investigated in a guinea pig model of immune-mediated hearing loss. Sterile labyrinthitis was created by injection of keyhole limpet hemocyanin into the inner ear after systemic sensitization to keyhole limpet hemocyanin with adjuvant. Labyrinthitis involves infiltration of inflammatory cells and hearing loss detectable 3 to 5 days after challenge with keyhole limpet hemocyanin., Methods: Etanercept was administered either systemically (2.5 mg) 30 minutes before intracochlear challenge with keyhole limpet hemocyanin, with a second intraperitoneal dose (2.5 mg) 3 days later or locally by long-term infusion into the scala tympani with an osmotic pump (5.0 microg/h for 7 days). Auditory evoked brainstem response thresholds were measured before and after treatment to determine hearing loss. Cochleas were evaluated for the amount of inflammation., Results: Hearing loss in the untreated systemic group averaged 71 +/- 21 dB versus 37 +/- 32 dB in the etanercept-treated animals (t test, P < 0.001). There was also less inflammation in the cochleas from etanercept-treated animals (t test, P < 0.01). Hearing loss with local administration of etanercept was 59 +/- 31 dB in the nontreated ears and 18 +/- 8 dB in the treated ears (t test, P < 0.02). Inflammation was also less (t test, P < 0.01). Etanercept was not ototoxic., Conclusion: Prompt intervention with the anti-inflammatory drug etanercept significantly reduces inflammation sufficient for substantive hearing preservation.

Objectives/hypothesis: The inner ear rapidly mounts an immune response that can lead to cochlear degeneration and permanent hearing loss. Identification of proinflammatory cytokine expression during the initiation of the response should lead to rational therapeutic strategies that block the response, reducing damaging sequelae., Study Design: A cochlear immune response to keyhole limpet hemocyanin (KLH) injected into the inner ear or subarachnoid space of sensitized animals was created. Etanercept was administered to a group of animals to blunt the immune response., Methods: Cochleae were immunoassayed for expression of interleukin-1beta, tumor necrosis factor-alpha, and interleukin-6 and evaluated for the amount of cochlear-infiltrated cells., Results: Tumor necrosis factor-alpha and interleukin-1beta were expressed by infiltrated cells shortly after KLH injection. Tumor necrosis factor-alpha was expressed whether the antigen was introduced with or without surgical trauma. Interleukin-1beta was also expressed by the cochlear fibrocytes during the immune response and in surgical control animals, but not after intrathecal injection of antigen. Interleukin-6 expression was minimal during the response. Based on this observation, animals were treated with systemic injection of Etanercept, which reduced cochlear infiltrating cell number and cochlear fibrosis., Conclusion: Interleukin-1beta expression is a general cochlear response to trauma, whereas tumor necrosis factor-alpha expression in the infiltrated immunocompetent cells is the cytokine that induces amplification of the response that leads to cochlear disease.

Processing of human temporal bones is a long, expensive process and the resulting celloidin sections are difficult to use for immunohistochemistry. We tested the ability of immunohistochemical assays to work in human temporal bones that were decalcified using a microwave oven. Tissue was trimmed to an approximate cube (1.5-2 cm/side) containing only the cochlea and immersed in fresh EDTA with paraformaldehyde every 6 h. This sized block required 190-400 h to decalcify. The decalcified tissue was embedded in paraffin and sectioned. Sections were immunoassayed with anti-cytochrome c oxidase, anti-neurofilament or anti-peripherin. All three antibodies labeled the appropriate structures. This procedure may stimulate advancement in the understanding of human inner ear pathology.

Anticentromere antibodies (ACA) are associated with systemic sclerosis (scleroderma) patients exhibiting the more benign or so called limited manifestation of the disease (lSSc). ACA reactivity is directed against multiple polypeptide targets, the smallest of which is designated CENP-A. CENP-A is not an abundant cellular constituent; therefore to maximize recovery, we developed a protocol with a minimum of steps to isolate CENP-A from a human cell line. The trace cellular amount of this protein clearly dictated the production of its recombinant counterpart to facilitate determination of the role of the CENP-A antigen in scleroderma pathogenesis. Here we describe the eukaryotic expression of CENP-A cDNA using baculovirus-mediated infection of insect cells. The non-fusion recombinant protein spans the natural residues of the human CENP-A protein and rCENP-A followed the same chromotographic sequence for purification as did the natural source. The availability of the bona fide antigen provided a critical standard upon which to document authenticity of the recombinant polypeptide. The two forms of this antigen have been compared and shown to exhibit similar physical and antigenic properties., (Copyright 1998 Academic Press)

The 68-kDa antigen detected in the sera of patients with autoimmune inner ear disease is known to represent the highly inducible heat shock protein 70 (hsp70). To evaluate the existence of anti-hsp70 in the sera of patients with Meniere's disease and to develop a more reliable method to detect this antibody, the sera of patients and controls were examined. Bovine kidney (MDBK) cells were cultured and some of them were heat shocked. Proteins in the cells were separated using sodium dodecyl sulfate polyacrylamide gel electrophoresis. Sera were reacted simultaneously with the blots of non-heat-shocked cells and heat-shocked cells. The serum was considered positive if the band in the 70-kDa location was denser in the lane with heat-shocked cells relative to non-heat-shocked cells. Presence of the antibody against the 68-kDa protein was compared with the result of immunoblotting with MDBK cells. In immunoblotting with MDBK cells, 33.3% of patients with Meniere's disease had anti-hsp70, while in the control group, only 5% had this antibody. Of the 60 cases, 13 were positive against both hsp70 and the 68-kDa protein, whereas 7 were positive only against hsp70 and 6 only against the 68-kDa protein. These differences appeared to result from the greater sensitivity of the differential anti-hsp assay and from difficulties in interpreting the results in blots with bovine inner ear extracts because of faint, broad, or overlapping multiple bands. Quite a number of patients with Meniere's disease have anti-hsp70, and it may be indicative of an immune etiology of the disease. The Western blot using heat-shocked and non-heat-shocked cells could be a reliable method to detect this antibody.

Immunoblotting against bovine inner ear extracts has previously identified a 68 kd antigen reactive with 22% to 58% of sera of patients with rapidly progressive sensorineural hearing loss (PSNHL) of suspected autoimmune causation. Efforts to purify and characterize this diagnostic antigen suggest that it is ubiquitous rather than inner ear-specific, and may represent the highly inducible heat shock protein (hsp) 70. The antigens identified by PSNHL sera and anti-hsp 70 monoclonal antibodies copurify on ion exchange and adenosine triphosphate affinity chromatography, and comigrate on one- and two-dimensional gel electrophoresis. Additionally, immunoblotting with positive patient sera shows dramatically increased expression of the 68 kd antigen by bovine kidney cells following heat shock in culture. Reactivity with stress proteins of various classes has been reported in a number of autoimmune diseases; however, anti-hsp 70 appears uniquely associated with ulcerative colitis and PSNHL.

The Western or protein blot has proven to be a valuable resource in detecting discrete, immunoreactive antigen targets associated with a variety of autoimmune diseases. As the roster of autoantigens has expanded, it has become increasingly common to tailor specific gel or blot conditions to a particular polypeptide antigen. Two such assays are reported here as applied to the fractionation and visualization of human centromere protein (CENP-A), a centromere autoantigen associated with the rheumatic disease, systemic sclerosis. The centromere antigens are effectively solubilized in the presence of 1 M MgCl2 to allow for further purification. CENP-A copurifies with the histone proteins, primarily H3 and H4. The two CENP-A-specific protein blot assays separate CENP-A from the histone proteins and enhance CENP-A immunoreactivity. The first assay is based on the use of acid-urea gels with a Triton X-100 concentration chosen to maximize separation of CENP-A from all the histones. The second assay is based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis to differentiate two very basic proteins of similar molecular weight, namely CENP-A and histone H3. For each gel system, a selective choice of associated immunoblot parameters allows for the reproducible discrimination of the CENP-A antigen.

Monoclonal antibodies (MoAb) were produced against somatic antigens of adult human liver fluke Opisthorchis viverrini. Earlier studies attached diagnostic potential to an 89-90 kD antigen present in both somatic extracts and in vitro culture supernatants as well as to the abundant 16-17 kD tegumental protein doublet. Mice made excellent immune responses to low dose somatic extract adsorbed onto nitrocellulose or to the 80-95 kD region of SDS gel Western blots. The antigen specificities of hybridomas reactive with somatic antigen by ELISA were determined by radioimmunoprecipitation or immunoblotting. Six MoAb reacted with the desired 16 kD tegumental protein. A 90 kD somatic protein was identified by 9 clones. By indirect immunofluorescence, monoclonals reactive with the 16 kD polypeptide identified the outermost surface of the tegument. The 90 kD antigen was associated with all major muscle systems, most strikingly the crossed subtegumental layers, oral and ventral suckers, pharynx and a thin layer surrounding caeca. The biochemical identity of this muscle-associated antigen is unknown, but it is clearly distinct from the previously identified species-specific 89 kD exoantigen. The 16 kD tegumental protein shares epitopes with a number of related flukes. However, 2 MoAb which react with this protein show no crossreaction.

Uncertainty as to the species diagnosis remains a serious problem in the management of snake venom poisoning. This is particularly so in areas inhabited by numerous species, the venoms of which elicit similar pharmacological effects and clinical symptoms and against which para-specific cross-neutralizing antivenom is not available. Attempts have been made to eliminate some of this ambiguity through the development of various immunodiagnostic tests. Tests based on ELISA are sensitive, specific and even quantitative and adaptable to field application. In the development of diagnostic tests for use in developing countries, however, practical consideration must be given to speed, cost, simplicity in terms of equipment and expertise, and stability to the climate and storage conditions. This may dictate further modification or selection of more suitable alternative methodologies. Furthermore, the test may have to allow more flexibility in accommodating local species distributions and to address probable complications of heterophile antibodies in test samples from rural people.

systemic lupus erythematosus (SLE) and related rheumatic and connective-tissue diseases are often associated with the production of antibodies directed against a variety of specific cellular components. Recent evidence indicates that two such autoantigens, the Sm and RNP antigens recognized by SLE sera, exist in small ribonucleoprotein complexes found in the nuclei of higher eukaryotes. Studies of the structure and function of these autoantigenic particles with human sera used as probes have been limited because of the multiplicity of autoantibodies often found in an individual serum. Through this communication, we report that MRL/Mp-+/+ (MRL/n) mice, which spontaneously develop a disease exhibiting many of the characteristics of human SLE, possess anti-RNP antibodies in addition to anti-Sm and anti-DNA as previously reported. Spleen cells from one such autoimmune mouse were used to produce a stable hybridoma secreting antibodies that react simultaneously with a protein of Mr 40,000 and a doublet of approximately 70,000, a pattern of reactivity identical to and characteristic of human SLE anti-RNP autoantibodies.

The La or SS-B antigen is associated with rheumatic diseases, systemic lupus erythematosus, and Sjogren's syndrome, and is part of a larger ribonucleoprotein complex. Immunoaffinity chromatography allowed for the efficient separation of the La antigen from the bulk of the cellular proteins, with a minimum of protease exposure. Protein blot analysis of the affinity-isolated material indicated a major immunoreactive polypeptide of 50,000 m.w. A comparison of this antigen in a number of mammalian sources (human, rabbit, and rat) suggested strong conservation of the native polypeptide m.w. Likewise, in a direct comparison of this antigen from Epstein-Barr virus-infected cells in which there are distinct differences in the antigen-associated RNA species, the immunoreactive polypeptide species were of similar size. The La protein is readily susceptible to endogenous proteolysis, with the resulting generation of smaller, discrete polypeptides that still retain antigenicity. By using the La protein to monitor potential degradation, we have developed a simple two-step procedure to isolate the La-associated snRNP complex. The complexes thus isolated provide material suitable as a source of both the active antigen and of the functional ribonucleoprotein complex.

A comparison of the immunologically reactive components of the highly conserved Sm and RNP autoantigens from various mammalian tissue sources suggested the complete absence of a major 26K to 27K Sm-specific polypeptide in rabbit thymus extracts prepared by conventional procedures. A simple modification of the solubilization protocol, achieved by sonicating a suspension of commercial rabbit thymus acetone powder in 0.35 M NaCI, gave an extract containing the full complement of immunologically reactive Sm and RNP proteins detectable in other mammalian species. Without further manipulation, extracts were immediately passed through an immunoaffinity column constructed from human SLE IgG with both anti-Sm and anti-RNP reactivities. The proteins of the purified Sm/RNP were recovered in sufficient quantities for direct analysis by protein staining or immunoblot assays. The antigenic polypeptides were recovered intact and consisted of a single 73K RNP-specific species together with Sm-specific proteins of 26K to 27K (a doublet) and 13K. These proteins were easily visible by protein stain as were nonantigenic components of 35K, 32K, 11K, and less than 10K. The same polypeptides were present in affinity-purified Sm/RNP from HeLa cells, although the RNP protein was slightly smaller. The resolution and integrity of the complexes isolated by this simple two-step procedure, requiring less than 4 hr for completion, is remarkable, and the protein composition of the product compares quite favorably with antigens isolated from other sources by considerably more lengthy and laborious procedures.

Venoms from Naja naja siamensis, Ophiophagus hannah, Bungarus fasciatus, Vipera russelli, Calloselasma rhodostoma and Trimeresurus albolabris have been studied by means of sodium dodecyl sulfate polyacrylamide gel electrophoresis and immunoblotting. The immunoblots were stained with rabbit homologous and heterologous antibodies. In general, the higher the mol. wt the protein the higher the immunogenicity although two proteins with mol. wts of 23,000 and 25,000 from O. hannah venom are extraordinarily immunogenic. Cross reacting and species specific venom proteins were readily identified by the immunoblot techniques. Only a small number of venom proteins were cross-reactive among the snake species tested while the remaining appeared to be species specific.

Patients with seropositive rheumatoid arthritis (RA) have elevated titers of precipitating antibody toward an antigen designated RA nuclear antigen (RANA). Anti-RANA reactivity has been associated with prior Epstein-Barr virus (EBV) infection. Using the protein blot technique, we have identified, in extracts of WI-L2, an EBV+ nonproducer B-lymphoblast line, a Mr 80,000 polypeptide that is reactive with anti-RANA-containing sera. This same polypeptide can be recovered from RANA precipitin bands. The Mr 80,000 polypeptide appears to be EBV-associated, as a homologous antigen was detected in two other EBV+ cell lines, Daudi and Raji, but was not present in three EBV- human cell lines tested, HeLa, BJAB, and Ramos. Anti-RANA antibodies and antibodies reactive with the Mr 80,000 polypeptide also appear coincidently in the sera of individuals exhibiting an EBV infection (infectious mononucleosis). Further analysis of the RANA-associated Mr 80,000 polypeptide suggested its identity with the previously recognized EBV-associated nuclear antigen designated EBNA. The Mr 80,000 antigen shares with EBNA the properties of being a heat-stable, DNA binding protein. EBNA is traditionally assayed by a complement fixation reaction and anti-Mr 80,000 antibodies were shown to be reactive when a complement fixation assay was used in the immunoblot. Finally, when the Mr 80,000 antigen was used to absorb an anti-RANA/anti-EBNA serum, both antibodies were reduced.

Differential immunoaffinity chromatography using a combination of autoimmune antibodies allows for the rapid bulk separation of specific small nuclear ribonucleoproteins (snRNPs). Passage of a HeLa cell extract over a column constructed of human anti-Sm autoantibodies results directly in the elution of complexes containing the small nuclear RNA species, U1, U2, U4, U5, and U6, and nine major polypeptides of molecular weight 69,000, 32,000, 27,000, 26,000, 18,500, 13,000, 11,000 doublet, and less than 10,000. Passage of crude extracts through a column bearing murine monoclonal antibodies directed against the 69,000 molecular weight (U1)RNP peptide gives an enriched population of U1 snRNP particles in the retained material. When the flowthrough material from the (U1)RNP column is passed through an anti-Sm column, the retained material is enriched in U2, U4, U5 plus U6 snRNP complex. The 69,000, 32,000, and 18,500 molecular weight polypeptides are confined to the U1 fraction while the remaining proteins are recovered in both fractions. The procedure is simple and rapid, producing complexes with a high degree of resolution and in sufficient yield to provide a ready source of snRNP complexes for functional studies.

Cells with receptors capable of binding self-antigens constitute a normal component of the B cell repertoire; these specificities appear to be represented in low levels within the expressed antibody population. In autoimmune disease, this potential-actual repertoire is skewed in favor of exaggerated autoantibody expression. The clones or specificities affected are characteristic, even diagnostic of the particular disease, yet individuals express but a relatively small subset of this complexity. "Marker" autoantibodies may or may not be included, but autoantibodies more typical of other, related diseases are usually present. Certain specificities are clearly implicated in the pathogenesis of the corresponding disease; others contribute to- or exacerbate pre-existing pathological conditions, and still others appear at present as epiphenomena. Organ-/tissue-specific autoantibodies largely fall into the first or perhaps second categories; those associated with the systemic rheumatic diseases fit better into the latter or latter two categories. As we learn eventually more about these antibodies and the full spectra of autoantigens with which they react, many more may be found to exert more central roles in pathogenesis. The distortion of the expressed repertoire represents but one aspect of a far more complex set of pre-dispositions, conditions, stimuli, contributory factors and perhaps coincidences involved in the onset and perpetuation of the disease. The AAb arise within the context of a disease more pervasive than just the autoantibodies themselves, however, in certain diseases the subsequent autoimmune response may surpass all other variables to constitute the single most clinically significant factor. In attempting to account for these individual specificities and their disease associations, certain models seem applicable to selected autoantibodies but not to others. Even in these selected cases, the models remain speculative; in no case can we categorically state how the specificities arose. Non-specific activation may contribute to- and expand the expressed autoantibodies, but such mechanisms generally fall short in terms of adequately explaining the specificities of autoantibodies, the overlapping sets, the polyclonality of the response against single autoantigens or the specific disease associations. Despite this theoretical criticism, empirically, non-specific mechanisms have given rise to mixtures of autoantibodies which appear identical at least in terms of specificities to their spontaneous counterparts in various rheumatic diseases.(ABSTRACT TRUNCATED AT 400 WORDS)

Antibodies to the Sm antigen are closely associated with the rheumatic disease systemic lupus erythematosus (SLE). The Sm antigen exists in the cell as part of a ribonucleoprotein complex containing at least 10 polypeptides and five small nuclear RNA. The major immunoreactive Sm species are three polypeptides of m.w. 27,000, 26,000, and 13,000. By using an MRL/1 mouse, a strain which spontaneously produces a disease with many of the characteristics of human SLE, we have produced an anti-Sm hybridoma specific for the 13,000 m.w. Sm polypeptide. This monoclonal antibody is sufficient to allow for the rapid bulk isolation of the entire class of Sm snRNP, and can be used sequentially with an anti-(U1)RNP monoclonal antibody to subfractionate the Sm snRNP particles.

The disease systemic lupus erythematosus is characterized by antibodies directed against two nuclear antigens, designated Sm and RNP. The two antigens from any one tissue can be distinguished on the basis of the polypeptides recognized by anti-Sm and anti-RNP specific sera. Multiple polypeptides were associated with RNP isolated from rabbit thymus. To determine if these polypeptides were species-specific, a comparison was made of this antigen among different mammalian species. We report that the native RNP antigen has a m.w. of 70,000 and is readily susceptible to proteolysis generating smaller polypeptides that still retain antigenicity. Such an analysis also demonstrated multiple Sm-specific polypeptides, including species of 13,000 and 29,000 m.w. Because the immunoreactive species are protein in nature, the role of RNA for the detection of Sm and RNP by assay procedures such as immunodiffusion and counterimmunoelectrophoresis was examined. RNP, while still antigenically active, becomes insoluble after RNAse treatment; Sm remains largely soluble after such treatment. Both antigens can be reconstituted from their separated protein and RNA moieties with restoration of precipitin reactivity.

Nuclear poly(A)-containing RNA of mouse ascites cells can be extracted in the form of 15-17S ribonucleoprotein complexes under conditions in which the bulk of the heterogeneous nuclear RNA is released as 30S complexes. The poly(A)-containing fraction of nuclear extracts has been resolved into two distinct components, 15 and 17 S; neither contains the two polypeptides of 30S ribonucleoprotein. The 17S particle contains approximately six polypeptide species of molecular masses 17,000-30,000 daltons. The 15S complex has four distinct polypeptides of higher molecular mass, including a prominent 80,000-dalton species.