Asunto(s)
Neurofibroma Plexiforme/patología , Neoplasias Palatinas/patología , Raíz del Diente/patología , Adulto , Diente Premolar , Neoplasias Encefálicas/complicaciones , Neoplasias Encefálicas/diagnóstico por imagen , Diagnóstico Tardío , Femenino , Estudios de Seguimiento , Humanos , Maxilar , Neurofibroma Plexiforme/complicaciones , Neurofibroma Plexiforme/diagnóstico por imagen , Neoplasias Palatinas/complicaciones , Neoplasias Palatinas/diagnóstico por imagen , Enfermedades Periapicales/diagnóstico por imagen , Enfermedades Periapicales/etiología , Enfermedades Periapicales/patología , Radiografía , Retratamiento , Tratamiento del Conducto Radicular , Raíz del Diente/diagnóstico por imagen , Diente no Vital , Adulto JovenRESUMEN
OBJECTIVE: To investigate the roles of CD59a in the protection of joint tissue in the context of murine antigen-induced arthritis (AIA). METHODS: AIA was triggered in CD59a-deficient (CD59a(-/-)) mice and in CD59a-sufficient (CD59a(+/+)) controls; the course and severity of disease were compared between groups. The effects on arthritis of restoring CD59 to the joint in CD59a(-/-) mice by use of a membrane-targeted recombinant CD59 were also explored. RESULTS: Disease, as assessed clinically by measurement of joint swelling on day 1 (P < 0.0001), day 2 (P < 0.01), and day 7 (P < 0.02) and histologically from indicators of joint damage on day 21 (P < 0.02), was significantly enhanced in CD59a(-/-) mice compared with CD59a(+/+) wild-type controls. Membrane attack complex (MAC) deposition in the arthritic joints of CD59a(-/-) mice was also increased compared with that in the joints of CD59a(+/+) controls. Restitution of CD59 activity in joints of CD59a(-/-) mice was attempted with soluble recombinant rat CD59 (sCD59) or with a novel membrane-targeted rat CD59 derivative (sCD59-APT542). Strong immunohistochemical staining of the synovial membrane and subsynovial tissue was apparent in sCD59-APT542-injected joints, but not in joints injected with untargeted sCD59. Intraarticular administration of sCD59-APT542 markedly ameliorated disease severity in CD59a(-/-) mice, knee swelling was significantly reduced over the time course of the disease, and joint damage, assessed histologically, was significantly milder on day 21 (P < 0.05). CONCLUSION: These data firmly implicate the MAC of complement as a major effector of joint damage in the murine AIA model of rheumatoid arthritis (RA), and they provide a rationale for the inhibition of MAC assembly as a therapeutic strategy for RA.
Asunto(s)
Artritis Reumatoide/inmunología , Antígenos CD59/inmunología , Adyuvantes Inmunológicos/farmacología , Animales , Artritis Reumatoide/genética , Antígenos CD59/genética , Antígenos CD59/farmacología , Complejo de Ataque a Membrana del Sistema Complemento/inmunología , Progresión de la Enfermedad , Eliminación de Gen , Predisposición Genética a la Enfermedad , Masculino , Ratones , Modelos Animales , Índice de Severidad de la EnfermedadRESUMEN
The glycolipid-anchored glycoprotein CD59 inhibits assembly of the lytic membrane attack complex of complement by incorporation into the forming complex. Absence of CD59 and other glycolipid-anchored molecules on circulating cells in the human hemolytic disorder paroxysmal nocturnal hemoglobinuria is associated with intravascular hemolysis and thrombosis. To examine the role of CD59 in protecting host tissues in health and disease, CD59-deficient (CD59(-/-)) mice were produced by gene targeting in embryonic stem cells. Absence of CD59 was confirmed by staining cells and tissues with specific antibody. Despite the complete absence of CD59, mice were healthy and fertile. Erythrocytes in vitro displayed increased susceptibility to complement and were positive in an acidified serum lysis test. Despite this, CD59(-/-) mice were not anemic but had elevated reticulocyte counts, indicating accelerated erythrocyte turnover. Fresh plasma and urine from CD59(-/-) mice contained increased amounts of hemoglobin when compared with littermate controls, providing further evidence for spontaneous intravascular hemolysis. Intravascular hemolysis was increased following administration of cobra venom factor to trigger complement activation. CD59(-/-) mice will provide a tool for characterizing the importance of CD59 in protection of self tissues from membrane attack complex damage in health and during diseases in which complement is activated.
Asunto(s)
Antígenos CD59/genética , Eliminación de Gen , Hemoglobinuria/genética , Hemólisis/genética , Animales , Plaquetas/química , Antígenos CD59/fisiología , Activación de Complemento , Venenos Elapídicos/farmacología , Eritrocitos/química , Femenino , Citometría de Flujo , Heterocigoto , Homocigoto , Leucocitos/química , Masculino , Ratones , Ratones Noqueados , Recuento de Reticulocitos , Caracteres SexualesRESUMEN
We report the cloning of cDNAs encoding multiple isoforms of the pig analogue of human decay-accelerating factor (DAF; CD55). Screening of a pig muscle cDNA library using a human DAF probe identified a single clone that encoded a DAF-like molecule comprising three short consensus repeats (SCR) homologous with the amino-terminal three SCR in human DAF, a serine/threonine-rich (ST) region, and sequence compatible with a transmembrane domain and cytoplasmic tail. Northern blot and RT-PCR analysis showed that pig DAF was expressed in a wide range of tissues. Additional isoforms of DAF were sought using RT-PCR and 3'-rapid amplification of cDNA ends followed by sequencing. Isoforms containing a GPI anchor and with differing lengths of ST region were identified; no isoform containing a fourth SCR was found. Cloning of the GPI-anchored isoform from granulocytes confirmed that it was identical with the original transmembrane isoform through the three SCR and first portion of ST and was derived from a frame shift caused by splicing out 176 bp of sequence. A panel of mAbs was generated and used to analyze the distribution and anchoring of pig DAF in circulating cells. Pig DAF was expressed on all circulating cells and was transmembrane anchored on erythrocytes, but completely or partially GPI anchored on granulocytes and mononuclear cells. The transmembrane isoform of pig DAF was expressed on Chinese hamster ovary cells and was shown to affect regulatory activity for the classical pathway of human complement, but was only marginally active against pig serum.
Asunto(s)
Antígenos CD55/biosíntesis , Antígenos CD55/química , Secuencia de Consenso , Secuencias Repetitivas de Aminoácido , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Antígenos CD55/sangre , Antígenos CD55/genética , Células CHO , Cricetinae , ADN Complementario/química , ADN Complementario/aislamiento & purificación , Vectores Genéticos , Humanos , Hígado/inmunología , Hígado/metabolismo , Masculino , Proteínas de la Membrana/química , Proteínas de la Membrana/genética , Ratones , Datos de Secuencia Molecular , Especificidad de Órganos/genética , Especificidad de Órganos/inmunología , Isoformas de Proteínas/biosíntesis , Isoformas de Proteínas/sangre , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , ARN Mensajero/biosíntesis , Ratas , Bazo/inmunología , Bazo/metabolismo , Porcinos , Testículo/inmunología , Testículo/metabolismoRESUMEN
The gene encoding the mouse analogue of the human complement regulator CD59 was cloned using a combination of long range PCR and genomic library screening. Sequence obtained showed that its genomic structure closely resembled that of the human CD59 gene, comprising 4 exons, each separated by a long intron region. The sizes of introns and exons were comparable to those of the human gene with the exception of the third intron which is 2.5 kb in the mouse compared to 7 kb in the human gene. All exon/intron boundaries conformed to the GT-AG rules for splicing. Radiation hybrid mapping localised mouse Cd59 between D2Mit333 and D2Mit127 on chromosome 2, a region homologous with human chromosome 11p13 where the human CD59 gene is localised. These data have permitted the construction of a gene targeting vector for the generation of transgenic mice deficient in CD59.