RESUMO
This study examined whether the forkhead transcription factors of O group 1 (FoxO1) might be involved in telomere biology during calorie restriction (CR). We used FoxO1-knockout heterozygous mice (FoxO1(+/-)) and wild-type mice (WT) as a control. Both WT and FoxO1(+/-) were subjected to ad libitum (AL) feeding or 30% CR compared to AL for 20 weeks from 15 weeks of age. The heart-to-body weight ratio, blood glucose, and serum lipid profiles were not different among all groups of mice at the end of the study. Telomere size was significantly lower in the FoxO1(+/-)-AL than the WT-AL, and telomere attrition was not observed in either WT-CR or FoxO1(+/-)-CR. Telomerase activity was elevated in the heart and liver of WT-CR, but not in those of FoxO1(+/-)-CR. The phosphorylation of Akt was inhibited and Sirt 1 was activated in heart tissues of WT-CR and FoxO1(+/-)-CR. However, the ratio of conjugated to cytosolic light chain 3 increased and the level of p62 decreased in WT-CR, but not in FoxO1(+/-)-CR. A marker of oxidative DNA damage, 8-OhdG, was significantly lower in WT-CR only. The level of MnSOD and eNOS increased, and the level of cleaved caspase-3 decreased in WT-CR, but not FoxO1(+/-)-CR. Echocardiography showed that the left ventricular end-diastolic and systolic dimensions were significantly lower in WT-CR or FoxO1(+/-)-CR than WT-AL or FoxO1(+/-)-AL, respectively. The present studies suggest that FoxO1 plays beneficial roles by inducing genes involved in telomerase activity, as well as anti-oxidant, autophagic, and anti-apoptotic genes under conditions of CR, and suggest that FoxO1 signaling may be an important mediator of metabolic equilibrium during CR.
Assuntos
Restrição Calórica , Fatores de Transcrição Forkhead/metabolismo , Miocárdio/metabolismo , Transdução de Sinais , Telômero , Animais , Peso Corporal , Caspase 3/metabolismo , Dano ao DNA , Proteína Forkhead Box O1 , Camundongos , Camundongos Knockout , Óxido Nítrico Sintase Tipo III/metabolismo , Tamanho do Órgão , Estresse Oxidativo , Superóxido Dismutase/metabolismoRESUMO
Patients with idiopathic Parkinson's disease (PD) appear to have reduced capacity for detoxification of certain environmental compounds. The glutathione S-transferases (GSTs) are candidate genes for PD because they are involved in the metabolism of pesticides and cigarette smoke. We investigated the relationship of the seven GST polymorphisms (GSTM1 deletion, GSTT1 deletion, GSTP1 rs1695, GSTO1 rs4925, GSTO1 rs11191972, GSTO2 rs156697 and GSTO2 rs2297235) and PD risk with special reference to the interaction with pesticide use or cigarette smoking among 238 patients with PD cases and 370 controls in a Japanese population. None of the GST polymorphisms were associated with PD. GSTO1 rs4925 and GSTO2 rs2297235 were found to be in strong linkage disequilibrium (D' = 0.98). Cigarette smoking was significantly associated with decreased risk of PD. However, no interaction of smoking with any of the GST polymorphisms was observed. Self-reported pesticide use was not associated with increased risk of PD. There was no evidence of interaction between self-reported pesticide use and either GST polymorphism. Our results suggest that the tested GST polymorphisms did not play an important role in PD susceptibility in our Japanese population. Our study does not give evidence of interaction between the GST polymorphisms and smoking may although this study provided sufficient statistical power to detect modest interaction. As for interaction between GSTP polymorphisms and pesticide use, the power of this study to detect an interactive effect was low due to a small number of pesticide users. Future studies involving larger control and case populations and better pesticide exposure histories will undoubtedly lead to a more thorough understanding of the role of the GST polymorphisms in PD development.
Assuntos
Glutationa Transferase/genética , Doença de Parkinson , Praguicidas/efeitos adversos , Polimorfismo Genético/genética , Fumar , Idoso , Exposição Ambiental/efeitos adversos , Feminino , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Doença de Parkinson/etiologia , Doença de Parkinson/genética , Doença de Parkinson/psicologia , Grupos Populacionais , Estudos Retrospectivos , Fatores de RiscoRESUMO
A 19-year-old man was punched on the back, and anterior chest pain appeared about 3 hours after injury. The patient was consulted a physician complaining of anterior chest pain. On chest X-ray, mediastinal emphysema was suspected, and transferred to our hospital. Chest computed tomography (CT) revealed mediastinal emphysema. On esophageal radiography and bronchofiberscopy, no abnormal findings were detected. Conservative therapy was conducted, and symptoms had gradually improved. On the 8th hospital day, mediastinal emphysema was improved on chest CT. The patient was discharged on the 10th hospital day. The most frequent cause of mediastinal emphysema after trauma is traffic or downfall accident, and no report on this condition after the punch on the back was found.
Assuntos
Lesões nas Costas/complicações , Enfisema Mediastínico/etiologia , Ferimentos não Penetrantes/complicações , Adulto , Dor no Peito/etiologia , Humanos , Masculino , Enfisema Mediastínico/diagnóstico por imagem , Enfisema Mediastínico/terapia , Tomografia Computadorizada por Raios XRESUMO
Recent studies suggest that some of the beneficial effects of 3-hydroxyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) may be due to their cholesterol-lowering independent effects on the blood vessels. Chronic inhibition of endothelial nitric oxide (NO) synthesis by oral administration of N(omega)-nitro-L-arginine methyl ester (L-NAME) to rats induces early vascular inflammation as well as subsequent arteriosclerosis. The aim of the study is to test whether treatment with statins attenuates such arteriosclerotic changes through their cholesterol-lowering independent effects. We investigated the effect of statins (pravastatin and cerivastatin) on the arteriosclerotic changes in the rat model. We found that treatment with statins did not affect serum lipid levels but markedly inhibited the L-NAME-induced vascular inflammation and arteriosclerosis. Treatment with statins augmented endothelial NO synthase activity in L-NAME-treated rats. We also found the L-NAME induced increase in Rho membrane translocation in hearts and its prevention by statins. Such vasculoprotective effects of statins were suppressed by the higher dose of L-NAME. In summary, in this study, we found that statins such as pravastatin and cerivastatin inhibited vascular inflammation and arteriosclerosis through their lipid-lowering independent actions in this model. Such antiarteriosclerotic effects may involve the increase in endothelial NO synthase activity and the inhibition of Rho activity.
Assuntos
Anti-Inflamatórios/farmacologia , Arteriosclerose/prevenção & controle , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Animais , Pressão Sanguínea/efeitos dos fármacos , Quimiocina CCL2/genética , Vasos Coronários/química , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/patologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica/efeitos dos fármacos , Imuno-Histoquímica , Lipídeos/sangue , Macrófagos/imunologia , Masculino , Monócitos/imunologia , NG-Nitroarginina Metil Éster/farmacologia , Nitratos/sangue , Óxido Nítrico Sintase/metabolismo , Nitritos/sangue , Nitroarginina/sangue , Peptidil Dipeptidase A/efeitos dos fármacos , Peptidil Dipeptidase A/metabolismo , Pravastatina/sangue , Pravastatina/farmacologia , Antígeno Nuclear de Célula em Proliferação/análise , Piridinas/sangue , Piridinas/farmacologia , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Endogâmicos WKY , Sístole , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta1 , Proteína rhoA de Ligação ao GTP/efeitos dos fármacos , Proteína rhoA de Ligação ao GTP/metabolismoRESUMO
The effect of SM12502 and CV6209, platelet-activating factor (PAF) receptor antagonists on corticosterone (B) secretion induced by ACTH was examined in the perfused adrenals of CD1 ICR (normal) and CD1 ICR nu/nu (athymic) mice. Bilateral adrenals were perfused in situ with an artificial medium equilibrated by 95% O2 + 5% CO2. Continuous infusion of 10 microM SM12502 or CV6209 inhibited the B response to 100 pg/ml ACTH markedly in normal mice but insignificantly in athymic mice. Infusion of PAF did not significantly affect B secretion in either normal or athymic mice. Administration of 0.1 microM of N-methylcarbamyl PAF, a nonmetabolizable PAF agonist, significantly increased B secretion in normal mice, but not in athymic mice. Infusion of SM12502 significantly depressed the B response to 10 microM forskolin or 1 mM dibutyryl cyclicAMP (cAMP) in normal mice, but not in athymic mice. The results indicate that endogenous PAF and its receptor may play a role in the ACTH-initiated signaling pathway at the phase after responsiveness to cAMP and its receptor may have little function in athymic mice.
Assuntos
Córtex Suprarrenal/efeitos dos fármacos , Hormônio Adrenocorticotrópico/farmacologia , Corticosterona/metabolismo , Glicoproteínas da Membrana de Plaquetas/antagonistas & inibidores , Compostos de Piridínio/farmacologia , Receptores de Superfície Celular , Receptores Acoplados a Proteínas G , Tiazóis/farmacologia , Córtex Suprarrenal/metabolismo , Animais , Bucladesina/farmacologia , Colforsina/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Camundongos Nus , TiazolidinasRESUMO
A 56-year-old man was admitted to our hospital due to gradually developing consciousness disturbance. He had an 11-year history of sero-negative rheumatoid arthritis (Stage III) maintained by daily administration of 10 mg of prednisolone and 300 mg of actarit. On admission, he showed meningeal irritation and a marked increase in eosinophils in his cerebrospinal fulid (CSF) (457/microliter), while eosinophils in his peripheral blood were not increased (0/microliter). Shortly after admission he fell into a coma. Upon measurement in the coma state, his peripheral blood eosinophil count was found to be increased (max: 1742/microliter). Parasitic infection, Angiostrongylus cantonensis in particular, was excluded both by repeated microscopic examination of CSF and by immunological approaches for CSF and serum. Serum examinations showed broad cross-reaction between various parasitic antigens and positive myeloperoxdase-antineutrophil cytoplasmic antibody (18 EU/ml). Three pulses of methylprednisolone (500 mg/day) followed by conventional prednisolone therapy (60 mg/day) was effective for alleviating the signs and symptoms of eosinophilic meningoencephalitis. In this patient, it was considered that the cerebrospinal angiitis resulting in eosinophilic meningoencephalitis had been elicited by immunological abnormalities.
Assuntos
Artrite Reumatoide/complicações , Eosinofilia/etiologia , Meningoencefalite/etiologia , Anticorpos Anticitoplasma de Neutrófilos/análise , Artrite Reumatoide/tratamento farmacológico , Autoimunidade , Biomarcadores/análise , Eosinofilia/diagnóstico , Eosinofilia/tratamento farmacológico , Humanos , Masculino , Meningoencefalite/diagnóstico , Meningoencefalite/tratamento farmacológico , Metilprednisolona/administração & dosagem , Pessoa de Meia-Idade , Peroxidase/imunologia , Prednisolona/administração & dosagem , Pulsoterapia , Resultado do Tratamento , Vasculite do Sistema Nervoso Central/complicações , Vasculite do Sistema Nervoso Central/diagnóstico , Vasculite do Sistema Nervoso Central/tratamento farmacológicoRESUMO
"Microrosette ependymoma," which is ependymoma with numerous microrosettes throughout the tumor, has rarely been reported. We describe an autopsy case of cervical cord ependymoma with two unusual features: the presence of numerous microrosettes and the formation of trabecular architecture. The tumor originated in the C2 segment of a man aged 23 years and gradually expanded over the following 15 years and 10 months until the entire cervical cord was involved. Beside the low grade of malignancy, the tumor cells exhibited a strong tendency to form microrosettes and trabecular architecture, which formed many perivascular pseudorosettes. The microrosettes mostly consisted of only two or a few more cells, in the absence of large rosettes. Thus the constituent cells were those forming perivascular pseudorosettes. Electron microscopy and immunohistochemistry characterized the ependymal properties of the microrosettes, whose lumina frequently contained fibril bundles similar to those of the Reissner's fiber fibrils, in addition to cilia and microvilli. The pathogenesis of the occurrence of numerous microrosettes is unknown; however, a defect in the mechanism of regulation of rosette formation and enlargement is the most likely explanation.
Assuntos
Ependimoma/patologia , Neoplasias da Medula Espinal/patologia , Adulto , Vértebras Cervicais , Ependimoma/metabolismo , Evolução Fatal , Humanos , Imuno-Histoquímica , Masculino , Microscopia Eletrônica , Neoplasias da Medula Espinal/metabolismoRESUMO
A 60-year-old man with renal cell carcinoma was treated of right nephrectomy and high dose administration of Interferon-alpha (IFN) in 1990. Three and half years after operation, he complained of cough and hemoptysis. Chest X-ray showed a abnormal shadow (5.5 x 3.5 cm) in the upper lung field. On chest CT, a tumor mass with small cavity was located at S2, attended with the speculation and pleural indentation. A rough nodule suspected daughter tumor was pointed out near the tumor mass. Laboratory investigation revealed mild leucocytosis, an elevated ESR and C reactive protein. On lymphocyte subset, CD 4/8 ratio was 0.8 and NK cell activity was 11%. Immunosuppressive acid protein (IAP) in serum was 1,137 ng/ml. No organisms or malignant cells could be demonstrated in the biopsy materials or sputum. Right thoracotomy and upper lobectomy was carried out. Postoperative pathological diagnosis was inflammatory pseudotumor. Namely, the lesion was occupied with variable admixture of lymphocytes, plasma cells, histiocytes, phagocytes included hemosiderin, foam cells and whorled fibrosis. Daughter tumor was scar tissue. Now, he is well without recurrence and his immune response is within normal level. Some discussion of the literature was mentioned.
Assuntos
Doenças Autoimunes/etiologia , Carcinoma de Células Renais/cirurgia , Granuloma de Células Plasmáticas/etiologia , Imunidade Celular , Interferon-alfa/efeitos adversos , Neoplasias Renais/cirurgia , Pneumopatias/etiologia , Nefrectomia , Doenças Autoimunes/imunologia , Relação CD4-CD8 , Granuloma de Células Plasmáticas/patologia , Granuloma de Células Plasmáticas/cirurgia , Humanos , Células Matadoras Naturais/imunologia , Pneumopatias/patologia , Pneumopatias/cirurgia , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/sangue , PneumonectomiaRESUMO
To investigate the mechanisms of T-cell-mediated cytotoxicity, we estimated the involvement of apoptosis-inducing Fas molecule on the target cells and its ligand on the effector cells. When redirected by ConA or anti-CD3 monoclonal antibody, a CD4+ T-cell clone, BK1, could lyse the target cells expressing wild-type Fas molecule but not those expressing death signaling-deficient mutants. This indicates the involvement of Fas-mediated signal transduction in the target cell lysis by BK1. Anti-CD3-activated but not resting BK1 expressed Fas ligand as detected by binding of a soluble Fas-Ig fusion protein, and the BK1-mediated cytotoxicity was blocked by the addition of Fas-Ig, implicating the inducible Fas ligand in the BK1 cytotoxicity. Ability to exert the Fas-mediated cytotoxicity was not confined to BK1, but splenic CD4+ T cells and, to a lesser extent, CD8+ T cells could also exert the Fas-dependent target cell lysis. This indicates that the Fas-mediated target cell lytic pathway can be generally involved in the T-cell-mediated cytotoxicity. Interestingly, CD4+ T cells prepared from gld/gld mice did not mediate the Fas-mediated cytotoxicity, indicating defective expression of functional Fas ligand in gld mice.
Assuntos
Antígenos de Superfície/imunologia , Citotoxicidade Imunológica , Proteínas de Membrana/imunologia , Linfócitos T Citotóxicos/imunologia , Animais , Sequência de Bases , Antígenos CD4/imunologia , Cricetinae , DNA , Humanos , Ligantes , Dados de Sequência Molecular , Transdução de Sinais , Solubilidade , Receptor fasRESUMO
We reported a case of ankylosing spondylitis which successfully underwent aortic valve replacement for combined aortic and mitral regurgitation. A 42-year-old man was admitted with symptoms of shortness of breath and anginal pain. He was previously diagnosed ankylosing spondylitis by an orthopedician A grade III/VI to and fro murmur was audible at the left sternal border. Retrograde aortography revealed severe aortic regurgitation and mild mitral regurgitation. Cardiac catheterization showed moderately pulmonary hypertension and high pulmonary artery wedge pressure. He underwent aortic valve replacement with SJM prosthetic valve. His postoperative course was uneventful. In Japan, ankylosing spondylitis is rare disease, and cardiac lesions associated with these conditions is seldom met to us. The surgical problems and management of these lesions are discussed.
Assuntos
Insuficiência da Valva Aórtica/cirurgia , Próteses Valvulares Cardíacas , Insuficiência da Valva Mitral/cirurgia , Espondilite Anquilosante/complicações , Adulto , Valva Aórtica/cirurgia , Insuficiência da Valva Aórtica/etiologia , Humanos , Masculino , Insuficiência da Valva Mitral/etiologiaRESUMO
An evaluation of the psychological and cosmetic morbidity of 31 patients who had undergone breast conserving treatment (BCT group) and 71 patients who had undergone radical mastectomy (RM group) revealed that 85% and 73%, respectively, were satisfied with their operative results. BCT appeared superior to RM in relation to body image, with 93% of the BCT group indicating BCT as a future choice of treatment, whereas only 35% of the RM group indicated RM as a future choice of treatment. For 59% of the BCT patients, the results were considered excellent or good by a physician, but fear of recurrence was frequently expressed by both groups even though an early stage of breast cancer had been significantly more common in the BCT group than the RM group. Sexual adjustment was the same in both groups. Body image was thus concluded to have been improved by BCT rather than RM, but psychological morbidity was essentially the same in both groups.
Assuntos
Imagem Corporal , Neoplasias da Mama/cirurgia , Mastectomia Radical/psicologia , Mastectomia/psicologia , Adaptação Psicológica , Adulto , Axila , Neoplasias da Mama/psicologia , Neoplasias da Mama/radioterapia , Terapia Combinada , Estética , Feminino , Humanos , Excisão de Linfonodo/psicologia , Mastectomia Radical Extensa/psicologia , Mastectomia Radical Modificada/psicologia , Pessoa de Meia-IdadeRESUMO
CD2 is an intercellular adhesion molecule that has been implicated in T cell activation and differentiation both in humans and mice. Although the ligand for human CD2 has been defined as LFA-3, that for murine CD2 has not been identified yet. To identify the ligand for mouse CD2, we generated a chimeric molecule consisting of the extracellular domain of mouse CD2 and human immunoglobulin (Ig)G1 Fc (mCD2Rg). A hamster monoclonal antibody (mAb), HM48-1, was established by screening mAbs that could block the binding of mCD2Rg to T cell lines at the ligand site. The putative mouse CD2 ligand recognized by this mAb was a glycosyl phosphatidylinositol-anchored glycoprotein with an apparent molecular mass of 45 kD, which were shared characteristics with human LFA-3. However, its expression was predominantly restricted to hematopoietic cells, unlike human LFA-3. Protein microsequencing analysis for the NH2-terminal 18 amino acid residues of the affinity-purified HM48-1 antigen revealed that it is almost identical with mouse CD48. This identity was further confirmed by the reactivity of HM48-1 with a soluble recombinant CD48 (sCD48) protein and the molecule recognized by a rat mAb raised against sCD48. A rat anti-CD48 mAb blocked the mCD2Rg binding as well as HM48-1. Moreover, sCD48 also inhibited the mCD2Rg binding to the cellular ligand. Finally, like anti-CD2 mAb, HM48-1 inhibited the phytohemagglutinin response and, when crosslinked, augmented the anti-CD3 response of splenic T cells. These results indicate that CD48 is a ligand for mouse CD2 and is involved in regulating T cell activation.
Assuntos
Antígenos CD/fisiologia , Antígenos de Diferenciação de Linfócitos T/metabolismo , Ativação Linfocitária , Receptores Imunológicos/metabolismo , Linfócitos T/imunologia , Animais , Anticorpos Monoclonais/imunologia , Sequência de Bases , Antígenos CD2 , Antígeno CD48 , Antígenos CD58 , Cricetinae , Ligantes , Masculino , Glicoproteínas de Membrana/fisiologia , Camundongos , Dados de Sequência Molecular , Ratos , Proteínas Recombinantes de Fusão/metabolismoRESUMO
The functional relevance of CD2-mediated signal transduction in triggering T cell receptor/CD3-independent natural killer cell cytotoxicity was investigated by introducing wild-type CD2 or signaling-deficient CD2 with truncated cytoplasmic region into a murine natural killer-like large granular lymphocyte clone lacking CD2 and T cell receptor/CD3. The introduction of wild-type CD2 led to CD2-dependent binding and cytotoxicity against P815 target cells. In contrast, the introduction of mutant CD2 with truncated cytoplasmic region led to comparable P815 binding but reduced cytotoxicity as compared with the wild type. These results provide a direct evidence for CD2-mediated triggering of NK cell cytotoxicity upon target cell binding.
Assuntos
Antígenos de Diferenciação de Linfócitos T/fisiologia , Receptores Imunológicos/fisiologia , Sequência de Aminoácidos , Animais , Antígenos CD2 , Células Clonais , Citotoxicidade Imunológica , Imunidade Celular , Técnicas In Vitro , Células Matadoras Naturais/fisiologia , Ativação Linfocitária , Camundongos , Dados de Sequência Molecular , Transdução de Sinais , TransfecçãoRESUMO
We have examined the functional property of murine CD2 as an intercellular adhesion molecule by using five anti-murine CD2 mAb which were classified into two groups according to their mutual competition in binding to cell surface CD2. Hamster fibroblasts transfected with murine CD2 cDNA exhibited increased conjugate formation with a murine mastocytoma P815 which expresses the putative murine LFA-3 mRNA detected by cross-hybridization with human LFA-3 cDNA under conditions of low stringency. This increase in conjugate formation was abrogated by both groups of anti-CD2 mAb, although some differences in the extent of inhibition were observed at lower concentrations of the mAb. We then examined the involvement of CD2 in several murine T cell responses by using these mAb to abrogate CD2-mediated cellular interactions. Anti-CD2 mAb significantly inhibited mitogenic T cell responses induced by suboptimal doses of Con A and PHA. In the allogenic MLR response and in the Ag response of two KLH/I-Ak-specific Th cell clones, the inhibitory effect of anti-CD2 mAb was also greatest under suboptimal conditions, i.e., with lesser doses of the Ag. These results indicate that the contribution of CD2 as an accessory molecule is variable, depending on the Ag dose used for stimulation, and they suggest that CD2 is involved in the Ag response of murine T cells under the physiologic conditions where only a limited amount of Ag is available. We next examined the contribution of CD2 to MHC-restricted cytotoxicity by CTL and to MHC-unrestricted cytotoxicity by NK and lymphokine-activated killer cells. Only a marginal inhibition by anti-CD2 mAb alone was observed. Anti-lymphocyte function-associated Ag (LFA)-1 mAb alone exhibited greater inhibitory effects than anti-CD2 mAb in all of the cases tested. In most cases, however, substantial levels of cytotoxicity remained, even in the presence of both anti-CD2 and anti-LFA-1 mAb. These results indicate a minor contribution of CD2, as compared with LFA-1, to cytotoxicity by murine CTL, NK cells, and lymphokine-activated killer cells, and they reveal the presence of undefined cellular interaction pathways other than those mediated by CD2 and LFA-1.
Assuntos
Antígenos CD/fisiologia , Antígenos de Diferenciação de Linfócitos T/fisiologia , Células Matadoras Naturais/fisiologia , Antígeno-1 Associado à Função Linfocitária/fisiologia , Receptores Imunológicos/fisiologia , Linfócitos T/fisiologia , Animais , Anticorpos Monoclonais/imunologia , Antígenos CD2 , Adesão Celular , Citotoxicidade Imunológica , Epitopos/análise , Ativação Linfocitária , Camundongos , Camundongos EndogâmicosRESUMO
CD2 and lymphocyte function-associated antigen (LFA)-1 are well known as T cell adhesion molecules involved in killer-target cell interactions. However, our recent study revealed that molecule(s) other than CD2 and LFA-1 might be involved in the lymphokine-activated killer (LAK) cell cytotoxicity against certain target cells. In order to characterize such unknown molecules, we established a mAb (RMV-7) which could inhibit CD2/LFA-1-independent LAK cell cytotoxicity and binding to target cells at the effector site. The Ag identified by RMV-7 appeared on splenic T cells late after mitogenic stimulation and was a noncovalently linked heterodimer composed of a 140-kDa alpha-chain and a 95-kDa beta-chain. RMV-7 blocked LAK cell binding to fibronectin (FN), fibrinogen, and vitronectin but not that to laminin or type IV collagen, indicating that the RMV-7-defined molecule is a unique extracellular matrix receptor for FN, fibrinogen, and vitronectin. One of its ligand, FN, was found on the surface of several target cells, and LAK cell cytotoxicity against them was blocked by anti-FN antibody at the target site. Similarly, cytotoxicity of a H-2d-specific CTL clone was inhibited by RMV-7 and anti-FN antibody as well. These results indicate that a unique very late activation Ag-like extracellular matrix receptor on murine CTL and LAK cells contributes to target cell binding and cytotoxicity.
Assuntos
Antígenos de Diferenciação de Linfócitos T/fisiologia , Citotoxicidade Imunológica , Matriz Extracelular/fisiologia , Células Matadoras Ativadas por Linfocina/fisiologia , Antígeno-1 Associado à Função Linfocitária/fisiologia , Receptores Imunológicos/fisiologia , Receptores de Antígeno muito Tardio/fisiologia , Animais , Anticorpos Monoclonais/imunologia , Antígenos de Superfície/imunologia , Antígenos CD2 , Linhagem Celular , Proteínas da Matriz Extracelular/metabolismo , Fibronectinas/fisiologia , Integrinas/fisiologia , Ativação Linfocitária , Camundongos , Peso Molecular , Receptores de Antígeno muito Tardio/imunologia , Linfócitos T Citotóxicos/imunologiaRESUMO
The activity of platelet-activating factor acetylhydrolase, a specific metabolizing enzyme of platelet-activating factor (PAF), in plasma of 39 male subjects was determined radiochemically by the method of Stafforini et al., (1987) J Biol Chem 262: 4223-4230, to clarify to what extent PAF affects atherosclerotic disorders induced by habitual smoking. The subjects examined included 18 habitual smokers (mean age: 62 +/- 10.6 years) and 21 age-matched nonsmokers. Plasma PAF acetylhydrolase activity was higher in the smokers than in the nonsmokers. There was no difference between smokers and nonsmokers in platelet aggregability in response to PAF or ADP. A higher apoprotein B/apoprotein A-I ratio in smokers as compared to nonsmokers was the only manifestation of abnormal lipoprotein metabolism in the former group. In the smokers, plasma PAF acetylhydrolase activity was directly proportional to total cholesterol, LDL-cholesterol, triglyceride, apoprotein B, LDL-cholesterol/HDL-cholesterol or apoprotein B/apoprotein A-I, and inversely proportional to HDL-cholesterol or apoprotein A-I. The results obtained suggest that alterations in PAF acetylhydrolase levels result from a slightly abnormal lipoprotein metabolism. Determination of plasma PAF acetylhydrolase activity is useful to study the role of PAF in atherosclerotic changes induced by smoking.
Assuntos
Fosfolipases A/sangue , Fosfolipases/sangue , Fumar/sangue , 1-Alquil-2-acetilglicerofosfocolina Esterase , Adulto , Idoso , Idoso de 80 Anos ou mais , Arteriosclerose/enzimologia , Arteriosclerose/etiologia , Humanos , Lipoproteínas/sangue , Masculino , Pessoa de Meia-Idade , Fator de Ativação de Plaquetas/análise , Agregação PlaquetáriaRESUMO
The differentiation of peripheral blood B lymphocytes into immunoglobulin-producing cells (Ig-PC) by pokeweed mitogen (PWM) and the function of concanavalin A (Con A)-induced suppressor T lymphocytes were examined to elucidate the late effects of atomic bomb radiation. A total of 140 individuals, 70 with an exposure dose of 100 rad or more and an equal number with an exposure dose of 0 rad matched by sex and age, were selected from the Nagasaki Adult Health Study (AHS) sample. Both the differentiation of peripheral blood B lymphocytes into Ig-PC by PWM and the function of Con A-induced suppressor T lymphocytes tended to be more depressed in the exposed group than in the control group, but a statistically significant difference could not be observed between the two groups. The function of Con A-induced suppressor T lymphocytes tended to decrease with age, but a statistical significance was detected only for percentage suppression against IgM-PC.