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B Wiggert

Publications and source records attributed to B Wiggert.

At least 127 records · Page 7Linked to original sources
PubMed1988

A new model of autoimmune disease. Experimental autoimmune uveoretinitis induced in mice with two different retinal antigens.

Experimental autoimmune uveoretinitis (EAU) is an organ-specific, T lymphocyte-mediated autoimmune disease, which serves as a model for several human ocular inflammations of an apparently autoimmune nature. EAU pathology in some rodents and in monkeys can readily be induced by immunization with several different retinal proteins; however, advancing research into the cellular mechanisms of this disease has raised the need for an EAU model in an immunologically and genetically well defined species. We report here the induction of EAU in the mouse, which has hitherto been considered a species refractory to EAU, with two retinal Ag, the retinal soluble Ag and the interphotoreceptor retinoid-binding protein. Although all the mouse strains tested exhibited lymphocyte responses and antibody titers to both retinal Ag, EAU was inducible in only some of the strains, and the uveitogenic responses to retinal soluble Ag and interphotoreceptor retinoid-binding protein appeared to be mutually exclusive. The EAU model in mice was found to differ in several respects from the EAU model in other rodent species. Induction of the disease was achieved with a relatively high dose of Ag and an intensified immunization protocol, and the onset of disease was later, the duration was longer, and the course was less acute. Anterior segment involvement was slight or nonexistent, and damage to the retina and uvea was of a focal rather than of a diffuse nature. Murine EAU appeared to approximate some types of human uveitis more closely than the EAU models described in other rodent species with respect to its pathologic manifestations as well as its more chronic course. The relatively longer duration of the active stage of disease in murine EAU should facilitate therapeutic intervention in established disease, which was not feasible in the more acute models of EAU. The extensive knowledge of the immunologic parameters of the mouse and the availability of genetically defined strains should be of great value in the study of cellular mechanisms and immunogenetics of ocular autoimmune disease.

Animals↗
PubMed1988

Interphotoreceptor retinoid-binding protein levels in subretinal fluid from rhegmatogenous retinal detachment and retinopathy of prematurity.

Interphotoreceptor retinoid-binding protein (IRBP) has been detected qualitatively in subretinal fluid associated with rhegmatogenous retinal detachments. We have used a quantitative enzyme-linked immunosorbent assay to determine the IRBP concentrations in 24 fluid specimens collected at retinal reattachment surgery from 22 patients, and from 17 patients who underwent surgery for retinopathy of prematurity with traction detachment. We observed a wide range of concentrations (1 to 176 micrograms of IRBP per milligram of protein). Higher concentrations were found only in fluid from the more recent rhegmatogenous detachments. The lowest concentrations were detected among fluids drained from under rhegmatogenous detachments ranging from five days' to one year's duration. The IRBP concentration in subretinal fluid showed no correlation with visual outcome and may be influenced by IRBP turnover in the vitreous cavity. Most strikingly, none of the 17 samples from patients with retinopathy of prematurity contained detectable amounts of IRBP.

Adult↗
PubMed1988

A developmental study of interphotoreceptor retinoid-binding protein (IRBP) in single and double homozygous rd and rds mutant mouse retinae.

Interphotoreceptor retinoid-binding protein (IRBP) was studied using immunochemical and immunocytochemical techniques in retinae of mice with allelic combinations at the rd and rds loci at different stages of development and degeneration. Until postnatal day 7 (P7), IRBP is located intracellularly in developing retinae of the different genotypes. Thereafter, IRBP is present mainly in the interphotoreceptor matrix. As previously noted, cell death is slowest in the heterozygous +/+,rds/+ mutant with loss increasing in order in +/+,rds/rds, rd/rd, rds/rds and rd/rd,+/+ animals. The IRBP content of the total retina also approximates this pattern, with lowest amounts by far in rd/rd, rds/rds and rd/rd,+/+ mutants (after P14). Interestingly though, IRBP loss significantly precedes visual cell loss in the rd/rd,rds/rds retina. In all the mutants, the remaining rod cells in the outer nuclear layer exhibit synthesis of intracellularly located IRBP at late stages of degeneration. In the single homozygous rd/rd,+/+ and the double homozygous rd/rd,rds/rds mutants, IRBP is present intracellularly during the entire degenerative process with somewhat less intracellular IRBP in the rd/rd,rds/rds mutant. Retinae of homozygous +/+,rds/rds and heterozygous +/+,rds/+ animals exhibit a normal distribution pattern of IRBP immunoreactivity until loss of photoreceptor cells becomes pronounced at later stages of the disease. Many of the remaining cells at this time are probably cone elements although they are structurally changed. Double labeling with IRBP and S-antigen demonstrates, in many but not all, the presence of both proteins in the same cell body. Immunocytochemistry clearly demonstrated the presence of IRBP in remaining photoreceptor cells at late stages of the disease. Thus, the biochemically measured loss of IRBP appears to be a complex process neither directly dependent on the loss of photoreceptor outer segments and reduced interphotoreceptor matrix space (e.g. there is a sustained IRBP level in rodless rds mutants) nor simply due to cell death (e.g. in the rd/rd,rds/rds mutant, IRBP loss significantly precedes cell loss). That this IRBP is mainly intracellular, however, may indicate an abnormality in secretion which, combined with other factors, induces a degenerated and less differentiated phenotype.

Animals↗
PubMed1988

Cyanogen bromide fragments of bovine interphotoreceptor retinoid-binding protein induce experimental autoimmune uveoretinitis in Lewis rats.

Interphotoreceptor retinoid-binding protein (IRBP), a retinal specific antigen, induces experimental autoimmune uveoretinitis (EAU) when injected into Lewis rats. Here we report that certain cyanogen bromide fragments of IRBP are capable of inducing EAU. Bovine IRBP, reduced and S-carboxymethylated, was subjected to cyanogen bromide cleavage. This CNBr digest was subjected to reversed-phase high performance liquid chromatography. Three fragments were purified to apparent homogeneity. These three fragments were subjected to gas-phase amino-terminal sequencing analysis. All three yielded single sequences, confirming their purity. On the basis of this amino-terminal sequencing and sequencing of cDNAs encoding bovine IRBP, two of these sequences, named CB-58 and CB-71, were localized to the C-terminal one-third of the IRBP molecule, whereas the third, a subfragment thought to result from cleavage at a tryptophan residue and named CB-47, was localized to the N-terminal one third of the protein. CB-71 and CB-47 shared a strong homology, suggesting a putative internal gene duplication event in the evolution of IRBP. All three of these fragments when injected into Lewis rats caused moderately severe EAU with early onset at relatively low doses. The histopathologic changes induced were indistinguishable from those caused by the intact protein. It would seem, therefore, that bovine IRBP contains multiple uveitogenic sites.

Amino Acid Sequence↗
PubMed1988

Lymphocyte responses to retinal-specific antigens in uveitis patients and healthy subjects.

A modified procedure for measuring human lymphocyte responses to retinal antigens was introduced and found to be highly sensitive. The main modifications are the use of round bottom culture wells, high antigen concentrations (up to 100 micrograms/ml) and extended incubation time (up to 9 days). Using this procedure, the majority of patients with uveitis, as well as a large proportion of healthy donors were found to respond positively (S.I. greater than or equal to 2.0) toward S-antigen and interphoto-receptor retinoid-binding protein. The responses to the retinal antigens were further enhanced by enriching the cultured lymphocytes for the helper/inducer subset. The responses to the retinal antigens were inferior to those against tuberculin (PPD), in particular in subjects who had been inoculated with BCG. The "secondary" responses to PPD were always higher in magnitude, were stimulated by markedly lower concentrations of antigen and were detected earlier in culture. The notion that the responses to retinal antigen in healthy donors are "primary" in nature was further supported by the findings that (a) lymphocytes from cord blood samples resembled adult lymphocytes in their response to S-Ag and (b) healthy donor lymphocytes which were prestimulated in vitro with S-Ag reacted to this protein by a specific "secondary" fashion. The possible involvement of lymphocytes with reactivity toward retinal antigens in pathogenic autoimmune processes in the eye is discussed.

Adult↗
PubMed1988

Synthetic peptides derived from IRBP induce EAU and EAP in Lewis rats.

In an earlier study we isolated three cyanogen bromide cleavage fragments of bovine IRBP that exhibited high levels of immunopathogenicity, producing inflammatory changes in the eyes (EAU) and pineal gland (EAP) of Lewis rats. These fragments have been localized within the IRBP sequence. In order to identify these putative immunopathogenic epitopes of IRBP, nine selected peptide sequences were synthesized and tested for the induction of disease in Lewis rats. Seven of the peptides were found inactive in producing disease while two closely related peptides, designated R4 (23-mer) and R9 (27-mer) were found to reproducibly induce EAU and EAP in immunized rats. No good correlation was found between the immunopathogenicity of the nine tested peptides and their amphipathicity: peptides R4 and R9 were not predicted to form strong amphipathic helices, while peptides selected for their high predicted helical amphipathicity were not immunopathogenic. EAU induced by peptides R4 and R9 was less severe and had a longer onset time than the disease induced by whole IRBP. In addition, the inflammatory changes induced by R4 and R9 in the posterior segment of the eye were less acute than those induced by whole IRBP and included granuloma formation and perivasculitis, features which are not generally seen in rats immunized with whole IRBP. Thus, the changes induced by R4 and R9 more closely resemble those which are characteristically found in human eyes affected by certain uveitic diseases than do changes produced by the intact protein.

Amino Acid Sequence↗
PubMed1987

Dissociation between lymphocyte activation for proliferation and for the capacity to adoptively transfer uveoretinitis.

We have shown previously that immunization with bovine interphotoreceptor retinoid-binding protein (IRBP) induces in rats severe eye disease, experimental autoimmune uveoretinitis (EAU). This study examined the uveitogenic capacity of IRBP of another species, the monkey, and tested the cross-antigenicity between these two proteins by a battery of immunological assays. Monkey IRBP was found to be approximately 20 times less uveitogenic in Lewis rats than bovine IRBP. High levels of cross-reactivity between bovine and monkey IRBP were demonstrated by antibodies as measured by the enzyme-linked immunosorbent assay, and by the radiometric ear test of delayed-type hypersensitivity, by using rats immunized with either one of the IRBP. On the other hand, lymphocytes from these rats failed to detect the cross-reactivity between the two IRBP by the proliferation response in culture. Yet, such lymphocytes did recognize the nonimmunizing IRBP when activated in culture for acquiring the capacity to adoptively transfer EAU into naive recipients. The data are discussed with regard to the limited usefulness of the lymphocyte proliferation assay for detection of immunopathogenic processes and the role of cross-reacting antigens in initiation of autoimmune responses.

Animals↗
PubMed1987

Uveitogenic potential of lymphocytes sensitized to interphotoreceptor retinoid-binding protein.

In our previous study rats immunized with bovine retinal interphotoreceptor retinoid-binding protein (IRBP) were found to develop inflammation in the eye and the pineal gland. This inflammatory disease was distinct in several aspects from experimental autoimmune uveoretinitis (EAU) induced by the retinal S-antigen (S-Ag). The current study examined the adoptive transfer of IRBP-induced EAU. We established that lymphocytes from IRBP immunized donor rats were capable of transferring EAU after in vitro stimulation with either IRBP (lymph node or spleen cells) or concanavalin A (spleen cells only). Recipients of these cells developed uveoretinitis and pinealitis identical to the actively induced disease. As compared with the S-Ag system, recipients of IRBP sensitized cells developed disease earlier, and smaller numbers of cells were needed to transfer EAU. Development of inflammation was directly related to a cellular response to the specific retinal antigen used for sensitization. Moreover, the unique nature of ocular inflammation was reestablished in the IRBP system: high proportions of polymorphonuclear leukocytes were found in the inflamed tissue of certain recipients despite a lack of a humoral response to the specific antigen. In contrast to the eye, only mononuclear leukocytes comprised the inflammation in the pineal gland.

Animals↗
PubMed1987

Experimental autoimmune uveoretinitis (EAU) induced by retinal interphotoreceptor retinoid-binding protein (IRBP): differences between EAU induced by IRBP and by S-antigen.

Rats immunized with the retinal interphotoreceptor retinoid-binding protein (IRBP) develop an inflammatory eye disease, "experimental autoimmune uveoretinitis" (EAU). The ocular changes which characterize the EAU induced by IRBP resemble those seen in rats which develop EAU by immunization with another retinal protein, S-antigen (S-Ag). Yet, the two antigens do not cross-react antigenically and the two diseases differ by several features: At low doses (less than or equal to 4 micrograms/rat), IRBP was more uveitogenic in Lewis rats than was S-Ag, inducing disease more reproducibly and with earlier onset time. On the other hand, at higher doses (greater than or equal to 20 micrograms/rat) the disease induced by S-Ag was more severe than that induced by the same doses of IRBP. Rats of various inbred strains differed in their susceptibility to EAU induced by these two antigens. In particular, BN rats were more susceptible to IRBP-induced EAU than to the S-Ag-induced disease, while WF and RCS-rdy+ rats developed severe EAU when immunized with S-Ag but showed minimal or no ocular change when immunized with IRBP.

Animals↗
PubMed1987

Uveitis induced in primates by IRBP: humoral and cellular immune responses.

In a previous publication, we have reported that immunization with bovine interphotoreceptor retinoid-binding protein (IRBP) produces severe uveitis in monkeys. The present study further examined the uveitogenicity of IRBP and analysed the immune responses in the immunized monkeys. Uveitis developed in monkeys immunized with bovine IRBP at doses as low as 10 micrograms Kg-1 body wt. In contrast, no disease was detected in monkeys immunized with monkey IRBP at the total dose of 100 micrograms Kg-1. Serum antibodies were measured in the immunized monkeys by the enzyme-linked immunosorbent assay, while cellular immunity was determined by skin hypersensitivity and the lymphocyte mitotic reaction in culture. No humoral or cellular immune responses were detected in monkeys immunized with monkey IRBP. Monkeys immunized with bovine IRBP produced antibodies which cross-reacted well with monkey IRBP. On the other hand, these monkeys did not react with monkey IRBP by skin hypersensitivity and their lymphocytes responded in culture to this protein only when tested by a highly sensitive procedure. In contrast, significant responses of the same cells to bovine IRBP were obtained at all tested conditions. These data are interpreted to suggest that the pathogenic cellular immune responses in vivo detect cross-reactivity with this autologous ocular antigen more efficiently than most conventional laboratory tests.

Animals↗
PubMed1987

Retinoblastoma. Immunohistochemistry and cell differentiation.

Tumor from eight enucleated eyes was analyzed by immunohistochemistry, using a panel of specific antibodies including interphotoreceptor retinoid-binding protein (IRBP), S-antigen (S-Ag), opsin, neuron-specific enolase (NSE), glial fibrillary acidic protein (GFAP), laminin, and vimentin. In addition, immunoelectron microscopy and enzyme-linked immunosorbent assay (ELISA) for IRBP were performed. Immunohistochemical staining disclosed the most pronounced labeling of tumor cells with NSE and IRBP antibodies. A correlation was found between the degree of tumor differentiation and amount of IRBP, a protein specifically synthesized by photoreceptor cells. Moderate labeling of the better differentiated tumors was also observed with antibodies against S-Ag and focal labeling in a few tumors with opsin antibodies. Anti-GFAP labeling was limited to a smaller number of reactive glial cells and perivascular glial cells. These data indicate the essential neuronal nature of retinoblastoma tumor cells in situ as well as at least partial photoreceptor-like features, as shown by the presence of recognized photoreceptor cell markers (IRBP, S-Ag, opsin). Tissue culture studies using the human Y-79 retinoblastoma cell line also demonstrate that the tumor cells are primitive multipotential retinoblasts capable of at least partial differentiation along neuronal, glial, or pigment epithelial cell lines.

Antibodies, Anti-Idiotypic↗
PubMed1987

Retinitis pigmentosa with segmental massive retinal gliosis. An immunohistochemical, biochemical, and ultrastructural study.

A morphologic, immunohistologic, and biochemical study was made on the eyes of a 79-year-old woman with clinically documented retinitis pigmentosa (RP). The methods included light and electron microscopy, immunohistologic staining, and biochemical analysis of interphotoreceptor retinoid-binding protein (IRBP) and cyclic nucleotides. Results from a histopathologic examination showed marked equatorial pigmentary retinal degeneration as well as peripheral chorioretinal atrophy corresponding to areas of paving stone chorioretinal changes. An unusual finding was a localized equatorial nodule in the right eye that stained with anti-glial fibrillary acidic protein (GFAP) antibodies, and showed lipid infiltrates in its margin and base. The equatorial retina showed marked gliosis of the outer layers. Photoreceptor cells were present only in the posterior retina, macula, and focally, in the far periphery. These areas corresponded to detectable IRBP assessed by immunohistochemical staining and biochemical analysis using the enzyme-linked immunosorbent assay (ELISA). Cyclic nucleotides were reduced in the peripheral retina, in areas of photoreceptor cell loss.

Aged↗
PubMed1987

Immunoelectron microscopic localization of photoreceptor-specific markers in the monkey retina.

Antibodies for several molecules that function in the visual process were used to localize these molecules in primate rod and cone cells. These antibodies (monoclonal or polyclonal) were prepared against Interphotoreceptor Retinoid-binding Protein (IRBP), S-antigen (S-Ag), opsin, alpha-transducin and also against cyclic GMP (cGMP). Lowicryl-embedded tissues were labeled with secondary antibodies linked to colloidal gold. Although IRBP is predominantly an extracellular protein, the relatively small amount found intracellularly was localized mainly in rods, with little in cones. Opsin, S-Ag and cGMP were found mainly in rod cell outer segments. A polyclonal antiserum raised against transducin-alpha purified from rod outer segments predominantly labeled rod cells, but an antiserum against the carboxyterminal decapeptide of transducin-alpha labeled both rod and cone cells. Thus, most of these specialized molecules are present predominantly in rod cells, confirming major differences in components of the visual cycle in rods and cones.

Animals↗
PubMed1987

IRBP from bovine retina is poorly uveitogenic in guinea pigs and is identical to A-antigen.

Retinal interphotoreceptor retinoid-binding protein (IRBP) is a potent uveitogen in Lewis rats, producing experimental autoimmune uveitis (EAU) reproducibly at doses lower than those of S-antigen (S-Ag). In contrast, IRBP was found to be poorly uveitogenic in three strains of guinea pigs, inducing only minor changes in a small proportion of these animals. On the other hand, S-Ag was found to induce EAU in the majority of immunized guinea pigs, with changes more severe than those induced by IRBP. Unlike the difference in their uveitogenicity, IRBP and S-Ag induced similar levels of specific immune responses in the immunized guinea pigs. The poor uveitogenicity of IRBP in guinea pigs resembles that of A-antigen (A-Ag). The two proteins are also similar in other features and were found in this study to be antigenically identical. It is proposed that IRBP and A-Ag are one and the same protein.

Animals↗
PubMed1987

Immunohistochemical analysis of experimental autoimmune uveoretinitis (EAU) induced by interphotoreceptor retinoid-binding protein (IRBP) in the rat.

Experimental autoimmune uveoretinitis (EAU) was induced in rats by immunization with bovine interphotoreceptor retinoid-binding protein (IRBP) and studied by immunohistochemistry. In general, the IRBP induction of inflammatory cellular components and expression of immune-related antigens on various non-lymphoid cells resembled those provoked by S-antigen (S-Ag). However, differences were found between the two diseases, including: 1) The increase in T suppressor/cytotoxic cells occurred in IRBP EAU more rapidly than in S-Ag EAU. 2) Fewer numbers of non-lymphoid cells expressed major histocompatibility complex class II surface antigens in IRBP EAU than in S-Ag EAU. The immunopathogenic mechanism of EAU induced by these two retinal antigens are discussed.

Animals↗
PubMed1986

Interspecies conservation of structure of interphotoreceptor retinoid-binding protein. Similarities and differences as adjudged by peptide mapping and N-terminal sequencing.

Structural properties of the retinal extracellular-matrix glycolipoprotein interphotoreceptor retinoid-binding protein (IRBP) from human, monkey and bovine retinas have been compared. SDS/polyacrylamide-gel-electrophoretic analysis of limited tryptic and Staphylococcus aureus-V8-proteinase digests show virtually identical patterns for the monkey and human proteins, whereas both sets differ considerably from the bovine protein pattern. Time-course digestion shows monkey IRBP to be more readily cleaved than bovine IRBP and also cleaved to smaller fragments. Also, reversed-phase h.p.l.c. of complete tryptic digests of the IRBPs indicate that, although they have in common a similar preponderance of hydrophobic peptides, all three proteins differ extensively in their fine structure. The N-terminal sequences of monkey and bovine IRBPs have been extended beyond those presented in our previous report [Redmond, Wiggert, Robey, Nguyen, Lewis, Lee & Chader (1985) Biochemistry 24, 787-793] to over 30 residues each. The sequences yet show extensive homology, differing at only two positions, although the major monkey sequence has an additional five amino acid residues at its N-terminus ('n + 5' sequence) not observed with bovine IRBP ('n' sequence). The newly determined N-terminal sequence of human IRBP demonstrates the presence of equal amounts of the 'n' and 'n+5' sequences that are qualitatively identical with those of the monkey. The presence of the five-amino-acid-residue extension in primate, but not bovine, IRBP may indicate variation in post-translational processing.

Amino Acid Sequence↗
PubMed1986

Retinal photoreceptor neurons and pinealocytes accumulate mRNA for interphotoreceptor retinoid-binding protein (IRBP).

We have utilized cDNA probes and in situ hybridization techniques to define the subcellular localization of interphotoreceptor retinoid-binding protein (IRBP) mRNA in bovine and monkey retinas. Results suggest that the mRNA is mainly localized in rod photoreceptor neurons within the outer nuclear layer of the retina. IRBP mRNA is also abundant in cells of the pineal gland, strengthening the analogy between rod photoreceptor cells and pinealocytes.

Animals↗