RESUMO
PURPOSE: Programmed death-1 (PD-1) ligation downregulates active lymphocyte responses. The authors tested whether PD-1 or its ligands are expressed in the posterior segment during active intraocular inflammation. METHODS: Experimental autoimmune uveitis (EAU) was induced using interphotoreceptor retinoid-binding protein (IRBP 161-180). Ocular inflammation was evaluated by histology and expression of PD-1 ligand tested by immunohistochemistry. PD-1 expression was evaluated by immunohistochemistry, RT-PCR, and Western immunoblotting. RESULTS: Using immunohistochemistry, PD-1, but not its ligands, was constitutively expressed in retinal neurons of naive mouse retina. Both PD-1 and its ligands were observed, as expected, in sites of active inflammation. CONCLUSIONS: PD-1 and its ligands were expressed in sites of active inflammation, in accordance with many other models of inflammatory disease. Surprisingly, PD-1, not previously described outside the immune system, was constitutively expressed in retinal neurons, raising the possibility that PD-1 signaling may be important for neuronal function in the absence of an inflammatory insult.
Assuntos
Antígenos de Superfície/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Doenças Autoimunes/metabolismo , Modelos Animais de Doenças , Uveíte Posterior/metabolismo , Animais , Antígenos de Superfície/genética , Proteínas Reguladoras de Apoptose/genética , Doenças Autoimunes/genética , Doenças Autoimunes/patologia , Antígeno B7-1/genética , Antígeno B7-1/metabolismo , Antígeno B7-H1 , Western Blotting , Encéfalo/metabolismo , Proteínas do Olho , Técnicas Imunoenzimáticas , Masculino , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Camundongos , Fragmentos de Peptídeos , Peptídeos/genética , Peptídeos/metabolismo , Proteína 2 Ligante de Morte Celular Programada 1 , Receptor de Morte Celular Programada 1 , RNA Mensageiro/metabolismo , Proteínas de Ligação ao Retinol , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Uveíte Posterior/genética , Uveíte Posterior/patologiaRESUMO
EAU in mice is a model of human posterior uveitis. EAU is a Th1-dependent disease that has been assumed to target the neural retina and related tissues; however, in situ effector cells and the target have not yet been clearly demonstrated. In the present study, we induced EAU in B10R mice by immunizing them with human interphotoreceptor retinoid-binding protein peptide 161-180. Histological examinations revealed that EAU occurred approximately 11 days after the immunization and reached a peak on day 14. Retinae from normal or EAU mice were treated with proteases to obtain mono-dispersed cells. The mono-dispersed cells thus obtained were separated into three to four fractions by discontinuous Percoll density-gradient (e.g. PBS/40/60) centrifugation. In normal mice, 94% of the total cells were recovered in two fractions (i.e. PBS/40 and pellet); and these fractions mainly contained inner and outer segments and cell bodies of photoreceptor cells and RPE cells, respectively. In EAU mice, additional cells (i.e. inflammatory cells) were obtained at the 40/60 interface. Electron microscopic examination showed that tissue damage during EAU was initiated by non-phagocytic destruction of inner segments by Mac-1(+) mononuclear cells on day 11, followed by phagocytic activity of macrophages against outer segments and RPE cells on day 14. In vitro culturing of normal retinal cells with EAU infiltrates suggested the involvement of TNF-alpha and NO in the tissue damage. These results indicate that EAU was initiated by non-phagocytic destruction of inner segments of photoreceptor cells by Mac-1(+) mononuclear cells.
Assuntos
Leucócitos Mononucleares/imunologia , Antígeno de Macrófago 1/imunologia , Fagocitose , Segmento Interno das Células Fotorreceptoras da Retina/imunologia , Uveíte Posterior/imunologia , Animais , Separação Celular , Células Cultivadas , Modelos Animais de Doenças , Proteínas do Olho/imunologia , Humanos , Macrófagos/imunologia , Camundongos , Opsinas/genética , Opsinas/imunologia , Proteínas de Ligação ao Retinol/imunologia , Uveíte Posterior/genéticaRESUMO
Vários estudos têm procurado identificar marcadores genéticos para doenças oftalmológicas. Dentre eles, destaca-se o antígeno de histocompatibilidade humano (Human Leukocyte Antigens). Situado no braço curto do cromossomo 6, o sistema antígeno de histocompatibilidade humano é conhecido por sua capacidade de conferir susceptibilidade ou proteção a diferentes doenças. Em virtude do seu acentuado polimorfismo, o tipo e a força da associação variam a depender da enfermidade e da raça (etnia) estudadas. O surgimento de métodos moleculares para tipificação dos alelos antígeno de histocompatibilidade humano e as recentes atualizações de sua nomenclatura têm contribuído para o melhor entendimento desse sistema. O presente trabalho tem por objetivos revisar a estrutura e função do sistema antígeno de histocompatibilidade humano e relatar suas associações com uveíte anterior aguda, penfigóide cicatricial ocular, ceratocone de início na juventude e retinocoroidopatia "birdshot".
Assuntos
Humanos , Oftalmopatias/imunologia , Antígenos HLA/imunologia , Alelos , Oftalmopatias/genética , Antígenos de Histocompatibilidade Classe I , Antígenos de Histocompatibilidade Classe II , Antígenos HLA/genética , Doenças Retinianas/genética , Doenças Retinianas/imunologia , Uveíte Posterior/genética , Uveíte Posterior/imunologiaRESUMO
Polymerase chain reaction (PCR) is a highly sensitive and specific method for detection and quantification of specific nucleic acids from a clinical sample. With its use, genetic, infectious, neoplastic, and autoimmune diseases can be diagnosed and managed with a high level of sensitivity, accuracy, and rapidity. This technique exactly reproduces unlimited copies of DNA, even if only a small amount are present initially. PCR assays can detect presence of fastidious and slow-growing microorganisms, such as chlamydia, mycoplasmas, mycobacterias, and viruses directly from clinical specimens and also can detect antimicrobial resistance. The value of viral load measurement by nucleic acid amplification in the management of patients with HIV infection or hepatitis C has also been well established. From the point of view of a clinician, the applications of PCR are focused mainly in the amplification and detection of diagnostic DNA segments from the genomes of both pathogens and patients.
Assuntos
Doenças Genéticas Inatas/diagnóstico , Infecções/diagnóstico , Reação em Cadeia da Polimerase/métodos , Doenças Reumáticas/diagnóstico , Artrite Infecciosa/diagnóstico , Artrite Infecciosa/genética , Artrite Reativa/diagnóstico , Artrite Reativa/genética , Resistência Microbiana a Medicamentos/genética , Oftalmopatias/diagnóstico , Oftalmopatias/genética , Amplificação de Genes , Doenças Genéticas Inatas/genética , Genética Microbiana , Genoma Humano , Humanos , Infecções/genética , Reação em Cadeia da Polimerase/classificação , Doenças Reumáticas/genética , Uveíte Posterior/diagnóstico , Uveíte Posterior/genética , Viroses/diagnóstico , Viroses/genéticaAssuntos
Biologia Molecular , Uveíte Posterior/genética , Síndrome de Behçet/genética , Síndrome de Behçet/imunologia , Doenças da Coroide/genética , Doenças da Coroide/imunologia , Antígenos HLA/genética , Vírus Linfotrópico T Tipo 1 Humano/genética , Vírus Linfotrópico T Tipo 1 Humano/imunologia , Humanos , Doenças Retinianas/genética , Doenças Retinianas/imunologia , Sarcoidose/genética , Sarcoidose/imunologia , Uveíte Posterior/virologia , Síndrome Uveomeningoencefálica/genética , Síndrome Uveomeningoencefálica/imunologiaRESUMO
Genomic rearrangements to the T-cell receptor (TCR) V beta 8 gene locus were examined in T cells derived from the lymph nodes of Lewis rats immunized with either S-Antigen or peptides derived from interphotoreceptor retinoid binding protein (IRBP). The cells used in these studies are from T-cell lines that have been selected by several cycles of antigen/IL-2 stimulations, or clones isolated from these lines. No apparent rearrangement of the V beta 8 gene was observed by Southern analysis, suggesting that if indeed there are T cells using V beta 8 gene elements they represent small proportions of the cells in these T-cell lines that induce EAU (uveitogenic T cells) and that the lines may consist of large numbers of clones. On the other hand, we have demonstrated V beta 8 gene expression in uveitogenic T-cell populations by Northern analysis and by polymerase chain reaction (PCR). Although V beta 8 gene transcripts were detectable in pathogenic, but not in non-pathogenic, T-cell lines using a V beta 8 cDNA probe, RNA from pathogenic T cell lines did not hybridize to another probe specific for rat V beta 8.2. Taken together, these results suggest that, unlike the T-cell lines that mediate experimental allergic encephalomyelitis (EAE), some T-cell lines that induce EAU do not predominantly express V beta 8.2 gene but other member(s) of the V beta 8 family.