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1.
J Med Genet ; 37(6): 415-21, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10851251

ABSTRACT

We report the results of a five year survey of FRAXA and FRAXE mutations among boys aged 5 to 18 with special educational needs (SEN) related to learning disability. We tested their mothers using the X chromosome not transmitted to the son as a control chromosome, and the X chromosome inherited by the son to provide information on stability of transmission. We tested 3738 boys and 2968 mothers and found 20 FRAXA and one FRAXE full mutations among the boys and none among the mothers. This gives an estimated prevalence of full mutations in males of 1 in 5530 for FRAXA and 1 in 23 423 for FRAXE. We found an excess of intermediate and premutation alleles for both FRAXA and FRAXE. For FRAXA this was significant at the 0.001 level but the excess for FRAXE was significant only at the 0.03 level. We conclude that the excess of intermediate and premutation sized alleles for FRAXA may well be a contributing factor to the boys' mental impairment, while that for FRAXE may be a chance finding. We studied approximately 3000 transmissions from mother to son and found five instabilities of FRAXA in the common or intermediate range and three instabilities of FRAXE in the intermediate range. Thus instabilities in trinucleotide repeat size for FRAXA and FRAXE are rare, especially among alleles in the common size range.


Subject(s)
Fragile X Syndrome/genetics , Genetic Testing , Mutation/genetics , Adolescent , Adult , Alleles , Child , Child, Preschool , DNA Mutational Analysis , Education, Special , England/epidemiology , Female , Fragile X Syndrome/diagnosis , Fragile X Syndrome/epidemiology , Fragile X Syndrome/physiopathology , Gene Frequency/genetics , Health Surveys , Humans , Karyotyping , Klinefelter Syndrome/diagnosis , Klinefelter Syndrome/epidemiology , Klinefelter Syndrome/genetics , Klinefelter Syndrome/physiopathology , Learning Disabilities/epidemiology , Learning Disabilities/genetics , Learning Disabilities/physiopathology , Male , Mothers , Prevalence , Time Factors , Trinucleotide Repeat Expansion/genetics , X Chromosome/genetics
2.
Proc Natl Acad Sci U S A ; 95(2): 719-24, 1998 Jan 20.
Article in English | MEDLINE | ID: mdl-9435259

ABSTRACT

There have been several claims of segregation distortion (meiotic drive) for loci associated with diseases caused by trinucleotide repeats, leading us to test for this phenomenon in a large study of the X-linked loci FRAXA and FRAXE. We found no evidence of meiotic drive in females and no convincing evidence in males, where the limitation of risk to daughters creates a testing bias for alleles of interest. Alleles for pre- and full mutation, intermediate alleles, and common alleles were analyzed separately, with the same negative results that are extended in the discussion to claims of meiotic drive for other diseases. On the other hand, an excess risk of learning difficulties was confirmed for intermediate FRAXA alleles (relative risk, 2.58 +/- .74) and suggested for intermediate FRAXE alleles. The penetrance of learning difficulty is low, the risk being estimated as .039 for FRAXA common alleles and .101 for intermediate alleles. Because of their lower gene frequency, full mutations are a less frequent cause of learning difficulty than intermediate alleles, which contribute .0020 to total prevalence and .0012 to attributable prevalence of learning difficulty.


Subject(s)
Genetic Linkage , Learning Disabilities/genetics , Trinucleotide Repeats/genetics , X Chromosome , Alleles , Chromosome Fragility , Female , Humans , Male
3.
J Infect Dis ; 176(5): 1334-43, 1997 Nov.
Article in English | MEDLINE | ID: mdl-9359736

ABSTRACT

Antigen Ov39, derived from Onchocerca volvulus, cross-reacts on both the T and B cell level with a nonhomologous human retinal antigen, hr44. Lewis rats were immunized to investigate the potential of these antigens to induce eye disease. Histologic and immunohistologic examination of ocular tissues revealed pathologic changes as early as day 12, which included induction or up-regulation of class II and CD68-like antigen on perivascular cells, ramified retinal microglia, dendritiform cells of the iris epithelium, and ciliary epithelium and significant breakdown of anterior and posterior blood-ocular barriers. Extravascular immunoglobulin and staining for CD68-like antigen was detected in the optic nerve after immunization with Ov39. Unrelated structural abnormalities of retina and lens seen in 8% of eyes examined significantly predisposed eyes to the development of Ov39- or hr44-induced pathology. These findings suggest a role for cross-reactive immune responses in the development of ocular onchocerciasis.


Subject(s)
Antigens, Helminth/immunology , Eye Diseases/etiology , Eye Proteins/immunology , Membrane Proteins/immunology , Microglia/pathology , Onchocerca volvulus/immunology , Retina/pathology , Animals , Antigens, CD/analysis , Antigens, Differentiation, Myelomonocytic/analysis , Cross Reactions , Eye/pathology , Glial Fibrillary Acidic Protein/analysis , Histocompatibility Antigens Class II/analysis , Humans , Immunization , Immunohistochemistry , Male , Rats , Rats, Inbred Lew
4.
Hum Mol Genet ; 6(2): 173-84, 1997 Feb.
Article in English | MEDLINE | ID: mdl-9063737

ABSTRACT

Factors involved in the stability of trinucleotide repeats during transmission were studied in 139 families in which a full mutation, premutation or intermediate allele at either FRAXA or FRAXE was segregating. The transmission of alleles at FRAXA, FRAXE and four microsatellite loci were recorded for all individuals. Instability within the minimal and common ranges (0-40 repeats for FRAXA, 0-30 repeats for FRAXE) was extremely rare; only one example was observed, an increased in size at FRAXA from 29 to 39 repeats. Four FRAXA and three FRAXE alleles in the intermediate range (41-60) repeats for FRAXA, 31-60 for FRAXE) were unstably transmitted. Instability was more frequent for FRAXA intermediate alleles that had a tract of pure CGG greater than 37 although instability only occurred in two of 13 such transmissions: the changes observed were limited to only one or two repeats. Premutation FRAXA alleles over 100 repeats expanded to a full mutation during female transmission in 100% of cases, in agreement with other published series. There was no clear correlation between haplotype and probability of expansion of FRAXA premutations. Instability at FRAXA or FRAXE was more often observed in conjunction with a second instability at an independent locus suggesting genomic instability as a possible mechanism by which at least some FRAXA and FRAXE mutations arise.


Subject(s)
Fragile X Syndrome/genetics , Trinucleotide Repeats , Alleles , Female , Haplotypes , Humans , Male , Mutation , Pedigree , Recombination, Genetic
6.
Hum Mol Genet ; 5(6): 727-35, 1996 Jun.
Article in English | MEDLINE | ID: mdl-8776586

ABSTRACT

Preliminary results on a large population-based molecular survey of FRAXA and FRAXE are reported. All boys with unexplained learning difficulties are eligible for inclusion in the study and data are presented on the first 1013 tested. Individuals were tested for the number of trinucleotide repeats at FRAXA and FRAXE and typed for four flanking microsatellite markers. Mothers of 760 boys were tested to determine the stability of the FRAXA and FRAXE repeats during transmission and to provide a population of control chromosomes. The frequency of FRAXA full mutations was 0.5%, which gives a population frequency of 1 in 4994, considerably less than previous reports suggest. No FRAXE full mutations were detected, confirming the rarity of this mutation. In the boys' X chromosomes, we detected one FRAXA premutation with 152 repeats and one putative FRAXE premutation of 87 repeats. No full or premutations were seen in the control chromosomes. A significant excess of intermediate alleles at both FRAXA and FRAXE was detected in the boys' X chromosomes by comparison with the maternal control chromosomes. This suggests that relatively large unmethylated repeats of sizes 41-60 for FRAXA and 31-60 for FRAXE may play some role in mental impairment. No instability was found in transmissions of minimal or common alleles in either FRAXA or FRAXE, but we saw two possible instabilities in transmission of FRAXA and two definite instabilities in transmission of FRAXE among 43 meioses involving intermediate or premutation sized alleles. We found no linkage disequilibrium between FRAXA and FRAXE but did find significant linkage disequilibrium between large alleles at FRAXE and allele 3 at the polymorphic locus DXS1691 situated 5 kb distal to FRAXE.


Subject(s)
Fragile X Syndrome/genetics , Learning Disabilities/genetics , Trinucleotide Repeats , X Chromosome , Adolescent , Child , Child, Preschool , Chromosome Mapping , Female , Genetic Testing , Humans , Linkage Disequilibrium , Male , Mothers
7.
Ophthalmic Res ; 28(5): 296-302, 1996.
Article in English | MEDLINE | ID: mdl-8979278

ABSTRACT

We describe a simple method for combining in situ hybridisation and immunohistochemistry on the same retinal section. The technique was developed using a radiolabelled cDNA probe for opsin and an antibody (ROS1F4) against rhodopsin. This method retains the antigenic sites if immunocytochemistry is performed prior to in situ hybridisation. Opsin mRNA was found in the photoreceptor inner segment with rhodopsin immunolocalised to the photoreceptor outer segments. The technique should be applicable to numerous situations including analysis of the sequence of events in the expression and synthesis of the various opsins during retinal development and degeneration.


Subject(s)
Immunohistochemistry/methods , In Situ Hybridization/methods , RNA, Messenger/analysis , Retina/chemistry , Rhodopsin/analysis , Rod Opsins/genetics , Antibodies, Monoclonal , DNA Probes/chemistry , Humans
8.
J Exp Med ; 182(4): 1121-31, 1995 Oct 01.
Article in English | MEDLINE | ID: mdl-7561685

ABSTRACT

Structural similarities between host self-antigens and infectious organisms may be involved in the expression of autoimmune reactivity and development of autoimmune disease. The unique eye pathology associated with Onchocerca volvulus infection, particularly the development of posterior segment lesions, may be promoted by such autoreactive responses. Ov39 is a parasite-derived antigen that has been shown previously to be antigenically cross-reactive with a 44,000-M(r) host ocular component. A clone, designated hr44, was isolated from a cDNA library of human retina by immunoscreen using serum to Ov39. A monoclonal antibody raised to Ov39 also reacted with hr44 and gave evidence for a shared conformational epitope. The primary structure analysis showed that identities between the antigens are limited and confined to small peptides. The cross-reactivity between the antigens appears to involve T cells, since Ov39-specific T cells can be stimulated by hr44, a neural-specific antigen. Based on secondary structure prediction, hr44 has the typical features of a membrane-associated type I antigen with an amino-terminal extracellular domain. mAbs and antisera localized the antigen in the optic nerve, neural retina, retinal pigment epithelium, as well as the epithelial layers of ciliary body and iris.


Subject(s)
Antigens, Helminth/immunology , Eye Proteins/genetics , Eye Proteins/immunology , Membrane Proteins/genetics , Membrane Proteins/immunology , Onchocerca volvulus/immunology , Retina/immunology , Amino Acid Sequence , Animals , Antibodies, Helminth/immunology , Antibodies, Monoclonal , Antigens, Helminth/genetics , Base Sequence , Cloning, Molecular , Cross Reactions , DNA, Complementary/genetics , Epitope Mapping , Eye/anatomy & histology , Eye Proteins/isolation & purification , Humans , Immunohistochemistry , Membrane Proteins/isolation & purification , Molecular Sequence Data , Rats , Sequence Analysis, DNA , Sequence Homology, Amino Acid , T-Lymphocytes/immunology
9.
Ann Trop Med Parasitol ; 87(6): 649-52, 1993 Dec.
Article in English | MEDLINE | ID: mdl-8122928

ABSTRACT

The ocular disease associated with infection with Onchocerca volvulus is unique in that there is a wealth of epidemiological evidence to support the casual nature of the association but there is little known about the pathogenic mechanisms involved. We have identified a 44,000 M(r) component of ocular tissues that shows immunological cross-reactivity with an O. volvulus antigen. This immunological cross-reactivity between parasite and a component of host tissues may underlie the development of ocular disease in onchocerciasis. Preliminary experiments indicate that it is possible to initiate ocular disease in susceptible rats using the recombinant parasite antigen. This should allow the development of a laboratory model of ocular onchocerciasis and further our understanding of the mechanisms by which an infective organism can produce an auto-immune-like disease in the host.


Subject(s)
Antigens, Helminth/immunology , Onchocerca volvulus/immunology , Onchocerciasis, Ocular/immunology , Animals , Autoimmune Diseases/etiology , Cross Reactions/immunology , Rats , Rats, Inbred Lew , Self Tolerance
10.
Invest Ophthalmol Vis Sci ; 34(10): 2888-902, 1993 Sep.
Article in English | MEDLINE | ID: mdl-8360022

ABSTRACT

PURPOSE: Onchocerca volvulus, a filarial worm, is a major cause of infectious blindness and inflammatory eye disease. An autoimmune cause for ocular onchocerciasis has been suggested since the identification of a recombinant antigen of O. volvulus that shows immunologic cross-reactivity with a host ocular component of 44,000 M(r). The aim of this study was to establish the distribution of the cross-reactive antigens in both host tissues and the parasite, and to determine if significant autoantibody responses to the host antigen could be detected in infected persons. METHODS: The tissue and organ distribution of the 44,000 M(r) antigen was determined by immunocytochemistry and Western blot analysis. Human autoantibody responses to the ocular antigen were demonstrated by Western blot analysis using sera collected from persons with onchocerciasis, with and without posterior segment pathology, Bancroftian filariasis, and Europeans with no filarial infection. RESULTS: The tissue distribution of the 44,000 M(r) antigen correlates with the sites of pathology in onchocerciasis and antibody reactivity against this antigen could be detected in all persons with onchocerciasis and posterior segment pathology. The antigen is also recognized by sera from persons with Bancroftian filariasis, but not from normal persons. CONCLUSIONS: A role is proposed for immunologic cross-reactivity in the pathogenesis of onchocerciasis and it is suggested that intraocular presentation of the cross-reactive parasite antigen by microfilariae is essential for the development of disease.


Subject(s)
Antigens, Helminth/immunology , Cross Reactions/immunology , Onchocerciasis, Ocular/immunology , Adult , Animals , Antibodies, Helminth/immunology , Autoantibodies/immunology , Blotting, Western , DNA, Protozoan , Electrophoresis, Polyacrylamide Gel , Elephantiasis, Filarial/immunology , Female , Humans , Immunoenzyme Techniques , Male , Middle Aged , Nucleic Acid Hybridization , Onchocerciasis, Ocular/pathology , Rabbits
11.
J Exp Med ; 174(1): 169-77, 1991 Jul 01.
Article in English | MEDLINE | ID: mdl-2056276

ABSTRACT

Onchocerciasis (river blindness) is a major blinding disease in Africa, Central America, and South America. Loss of vision can be due to corneal change, optic atrophy, or chorioretinal disease. It has been suggested that autoimmunological reactions resulting from crossreactivity between parasite antigens and components of eye tissues contribute to development of ocular pathology. Using sera collected from onchocerciasis patients as a screening reagent, a cDNA clone (Ov39) has been isolated from a lambda gt11 expression library of Onchocerca volvulus. This antigen exhibits immunological crossreactivity with a component of retinal pigment epithelium cells (RPE). Antiserum raised against this recombinant peptide immunoprecipitates a 22,000 Mr antigen of adult O. volvulus and recognizes a 44,000 Mr component of bovine RPE by Western blotting. A 44,000 Mr antigen of cultured human RPE metabolically labeled with 35S-methionine can be immunoprecipitated with the same antiserum. An antigen of the same size is recognized by a rabbit antiserum raised against whole O. volvulus extract. Immunocytochemical studies on cryostat sections of the bovine eye using the antirecombinant sera localizes this antigen to the RPE.


Subject(s)
Antigens, Helminth/genetics , Antigens/genetics , Onchocerca/genetics , Onchocerciasis, Ocular/immunology , Pigment Epithelium of Eye/immunology , Amino Acid Sequence , Animals , Antigens/immunology , Antigens, Helminth/immunology , Base Sequence , Cattle , Cloning, Molecular , Cross Reactions , DNA/genetics , DNA/isolation & purification , Female , Fluorescent Antibody Technique , Gene Library , Humans , Male , Molecular Sequence Data , Molecular Weight , Onchocerca/immunology , Protein Biosynthesis , RNA, Messenger/genetics , Recombinant Proteins/immunology , Retina/cytology
12.
Br J Ophthalmol ; 75(1): 54-60, 1991 Jan.
Article in English | MEDLINE | ID: mdl-1991090

ABSTRACT

Light microscopy (including fluorescence microscopy) and electron microscopy were applied to a study of the photoreceptor-retinal pigment epithelium (RPE) complex in a human eye which had been severely traumatised nine months prior to enucleation. The main feature of interest was a massive accumulation of lipofuscin in the retinal pigment epithelium at the posterior pole, and quantitative fluorescence microscopy provided values three times those obtained in appropriate control tissue. The photoreceptor layer was normal at the posterior pole but became progressively atrophic towards the periphery. The concentration of lipopofuscin was proportional to the degree of preservation of the retinal photoreceptors. By electron microscopy the cells in the RPE were seen to be packed with a mixture of lipofuscin granules and melanolysosomal complexes, but occasional photoreceptor phagosomes were found. Bruch's membrane and the choriocapillaris were normal. We attribute this hitherto unreported abnormality of the RPE after trauma to a dysfunction consequent on an overload of the monolayer by photoreceptor debris at the time of trauma.


Subject(s)
Eye Injuries/metabolism , Lipofuscin/analysis , Pigment Epithelium of Eye/chemistry , Cell Count , Cytoplasmic Granules/ultrastructure , Eye Injuries/pathology , Humans , Male , Melanocytes/ultrastructure , Microscopy, Electron , Middle Aged , Photoreceptor Cells/ultrastructure , Pigment Epithelium of Eye/ultrastructure
13.
Br J Ophthalmol ; 74(7): 393-9, 1990 Jul.
Article in English | MEDLINE | ID: mdl-2378854

ABSTRACT

Immunohistochemical investigations were conducted on surgically excised epiretinal membranes to determine how cellular and extracellular components of proliferative vitreoretinopathy membranes change with time. Specimens of less than four months' duration contained a significantly higher proportion of retinal pigment epithelial cells than later membranes. No association was found between membrane duration and the content of collagen subtypes I to IV and laminin, but 'early' specimens contained significantly more fibronectin than did 'late' membranes. Fibronectin and collagens I, III, and IV showed a variable relationship with glial cells and were most consistently associated with retinal pigment epithelial and fibroblast-like cells. These observations may explain some of the surgical features of epiretinal membranes.


Subject(s)
Retina/pathology , Retinal Diseases/pathology , Vitreous Body/pathology , Cell Division , Collagen/analysis , Eye Diseases/pathology , Fibroblasts/pathology , Fibronectins/analysis , Humans , Membranes/analysis , Membranes/pathology , Pigment Epithelium of Eye/pathology , Retina/analysis
14.
Invest Ophthalmol Vis Sci ; 31(4): 670-6, 1990 Apr.
Article in English | MEDLINE | ID: mdl-2335435

ABSTRACT

We have investigated the activities of four lysosomal enzymes in RPE cells isolated from three regions of the canine fundus: the tapetal area, the central pigmented area and the peripheral area. The results obtained with freshly isolated cells showed that the activities of acid phosphatase, B-glucuronidase and N-acetyl-B-glucosaminidase were significantly higher in RPE cells derived from the peripheral region when compared to those from the two central regions. In contrast, the activity of cathepsin D was significantly higher in the tapetal region than in the periphery. The regional distribution of both acid phosphatase and B-glucuronidase observed in fresh RPE cells was progressively lost when these cells were grown in culture. Estimations of photoreceptor density per RPE cell from each of the regions indicated that the number of photoreceptors per RPE cell did not vary significantly with retinal location and suggested that variations in enzyme content were not related to differences in photoreceptor cell distribution.


Subject(s)
Lysosomes/enzymology , Pigment Epithelium of Eye/enzymology , Animals , Cell Separation , Cells, Cultured , Dogs , Melanins/pharmacology , Pigment Epithelium of Eye/cytology , Therapeutic Irrigation , Tissue Distribution
15.
Exp Eye Res ; 50(3): 281-8, 1990 Mar.
Article in English | MEDLINE | ID: mdl-2318272

ABSTRACT

Previous studies have shown that bovine retinas incubated with [3H]galactose incorporated it, unmodified, into large molecules. Light and electron microscope autoradiography showed a significant proportion of the label to be in cone inner segments, and pulse-chase studies showed it was subsequently transported to the synaptic pedicles. In this report, evidence is presented to show that the galactose-labelled macromolecules are resistant to hydrolysis by proteolytic enzymes, testicular hyaluronidase, chondroitinase ABC, beta-glucosidase and beta-glucuronidase, but are readily degraded by alpha-amylase and beta-galactosidase, and to a lesser extent by beta-amylase. Treatment with alpha-amylase also leads to specific removal of radioactivity from cone inner segments and pedicles, as judged by light-microscopic autoradiography. These studies appear to indicate that the cone-specific galactose label is in glycogen or glycogen-like molecules.


Subject(s)
Galactose/metabolism , Glycogen/metabolism , Photoreceptor Cells/metabolism , Animals , Autoradiography , Cattle , Chromatography, Gel , Chromatography, Ion Exchange , Electrophoresis, Polyacrylamide Gel , Hydrolysis
16.
Br J Ophthalmol ; 73(4): 297-302, 1989 Apr.
Article in English | MEDLINE | ID: mdl-2713310

ABSTRACT

We report for the first time to our knowledge the histopathological findings in the eye of a patient with type II mesangiocapillary glomerulonephritis (dense deposit disease) in which a deposit of material morphologically very similar to that which is pathognomonic for the disease in the kidney was demonstrated in Bruch's membrane. The nature of the deposit in the renal lesion is unknown but is considered to represent a structural alteration secondary to a reaction with anticomplement antibody. Clinically the fundus appearance resembled that seen in drusen.


Subject(s)
Choroid/pathology , Glomerulonephritis, Membranoproliferative/pathology , Adolescent , Basement Membrane/pathology , Fluorescein Angiography , Humans , Male
17.
Invest Ophthalmol Vis Sci ; 30(1): 82-9, 1989 Jan.
Article in English | MEDLINE | ID: mdl-2912915

ABSTRACT

Although the incomplete degradation of phagocytosed outer segment discs is thought to result in the formation of lipofuscin, there has to date been no proof of this concept. We report for the first time that cultured human retinal pigment epithelial (RPE) cells fed daily doses of isolated rod outer segments for periods of up to 3 months were capable of developing intracellular autofluorescent granules whose morphology and fluorescence characteristics were similar to lipofuscin. These autofluorescent granules were observed as early as 2 weeks following daily challenge with rod outer segments and the number of granules increased with the number of challenge doses until the experiment was terminated after 3 months of daily feeding. We also studied the effects of the antioxidant vitamin E and a drug, Centrophenoxine, which has been purported to slow the formation of lipofuscin formation in vivo. Neither of these additives given either with the challenge or subsequently had any effect on the formation of the intracellular granules. In conclusion, the development of these "lipofuscin-like" inclusions in cultured RPE may provide a model with which to study ageing processes and may provide an understanding of the increased lipofuscin accumulation observed in certain retinal pathologies.


Subject(s)
Cytoplasmic Granules/metabolism , Lipofuscin/biosynthesis , Pigment Epithelium of Eye/metabolism , Pigments, Biological/biosynthesis , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Cytoplasmic Granules/ultrastructure , Fluorescence , Humans , Microscopy, Electron , Microscopy, Fluorescence , Middle Aged , Pigment Epithelium of Eye/ultrastructure
18.
Acta Ophthalmol (Copenh) ; 66(5): 514-21, 1988 Oct.
Article in English | MEDLINE | ID: mdl-3064535

ABSTRACT

We describe the production of hybridomas producing antibody reactive with retinal pigment epithelium. The patterns of reactivity obtained when supernatants from these hybrids were used to immuno-stain ocular and non-ocular tissues are described. From the patterns of reactivity obtained we suggest that the RPE shares common features with simple and glandular epithelia as well as myoepithelial cells. These findings may lend support to the hypotheses of RPE cell migration and contraction in the formation of epiretinal membranes and retinal detachment.


Subject(s)
Hybridomas/immunology , Pigment Epithelium of Eye/immunology , Animals , Antibodies/analysis , Cats , Cattle , Fluorescent Antibody Technique , Immunoenzyme Techniques
19.
J Cell Sci ; 91 ( Pt 2): 303-12, 1988 Oct.
Article in English | MEDLINE | ID: mdl-2477385

ABSTRACT

The cytoskeletal elements of normal (in situ) and cultured human retinal pigment epithelium (RPE) were studied by a variety of immunocytochemical techniques. Primary antibodies to vimentin and cytokeratins were used. Positive immunoreactivity for vimentin was obtained with in situ and cultured material. The pattern of reactivity obtained with antisera and monoclonals to cytokeratins was more complex. Cytokeratin immunoreactivity could be demonstrated in situ and in cultured cells. The pattern of cytokeratin expression was similar to that of simple or glandular epithelia. A monoclonal antibody that specifically recognizes cytokeratin 18 identified a population of cultured RPE cells that had particularly well-defined filamentous networks within their cytoplasm. Freshly isolated RPE was cytokeratin 18 negative by immunofluorescence, but upon culture cytokeratin 18 positive cells were identifiable. Cytokeratin 18 positive cells were identified in all RPE cultures (other than early primaries), regardless of passage number, age or sex of the donor. In post-confluent cultures cytokeratin 18 cells were identified growing over cytokeratin 18 negative cells, suggesting an association of cytokeratin 18 immunoreactivity with cell proliferation. Immunofluorescence studies of retinal scar tissue from two individuals revealed the presence of numerous cytokeratin 18 positive cells. These findings indicate that RPE cells can be identified by their cytokeratin immunoreactivity and that the overt expression of cytokeratin 18 may be associated with proliferation of human RPE both in vitro and in vivo.


Subject(s)
Cytoskeleton/ultrastructure , Pigment Epithelium of Eye/ultrastructure , Aged , Aged, 80 and over , Cell Division , Cells, Cultured , Fluorescent Antibody Technique , Humans , Keratins/analysis , Pigment Epithelium of Eye/analysis
20.
Eye (Lond) ; 2 Suppl: S180-201, 1988.
Article in English | MEDLINE | ID: mdl-3076146

ABSTRACT

The immunochemistry of the outer retina is discussed with particular reference to photoreceptor cells, the retinal pigment epithelium and the interphotoreceptor space. The antigens identified and the techniques utilised are summarised.


Subject(s)
Antigens/analysis , Retina/immunology , Animals , Humans , Immunochemistry , Pigment Epithelium of Eye/immunology
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