Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Twenty six patients with sarcoidosis of recent onset or with severe progressive disease were studied for evidence of retroviral infection. Peripheral blood mononuclear cells (PBMC) were cultured in vitro and stimulated with phytohaemagglutinin and interleukin-2. Induction of syncytia (SI) and production of reverse transcriptase (RT) were sought as indicators of possible retroviral infection. PBMC from two patients showed syncytia formation and in one of these two there was associated production of low levels of reverse transcriptase. The remaining patients showed neither RT nor SI activity. The predominantly negative results of this study indicate that sarcoidosis is unlikely to be of retroviral aetiology; however, cell populations from sites of active disease should be studied before drawing this conclusion.
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PMID:Search for a retroviral cause for sarcoidosis: no evidence from peripheral blood studies. 171 73

A retrovirus is spontaneously released into the culture medium of the equine sarcoid-derived MC-1 cell line. The MC-1 virus did not exhibit in vitro transforming activity or replication when tested on equine fibroblasts or a variety of other mammalian cell cultures. Complementary DNA, synthesized using detergent-activated MC-1 virus RNA-dependent DNA polymerase, detected homologous sequences in the DNA of an established equine dermal cell line and in the DNA of primary equine dermal fibroblasts. Iododeoxyuridine or azacytidine induced a replication-deficient endogenous retrovirus in the normal fibroblasts and amplified the production of MC-1 virus by the tumor cells. It was concluded that the endogenous virus, repressed in normal equine cells, is spontaneously expressed by the tumor cells.
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PMID:Spontaneous expression of an endogenous retrovirus by the equine sarcoid-derived MC-1 cell line. 394 9

A virus with the morphologic and biochemical properties of the family Retroviridae has been isolated from cultured cells explanted from a malignant tumor induced by intradermal inoculation of equine sarcoid cells into a combined immunodeficient Arabian foal. By electron microscopy, intracytoplasmic, extracellular, and budding particles measuring 89 to 120 nm with electron-lucent cores were seen. Virus purified from the medium of cultured cells had a buoyant density of 1.15 g/cm3 in isopycnic sucrose-gradient centrifugation, incorporated radiolabeled uridine but not thymidine, and had constitutive RNA-dependent DNA polymerase which required Mn2+ for optimal endogenous activity.
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PMID:Isolation of a retrovirus from cultured equine sarcoid tumor cells. 709 44

T lymphocytes in bronchoalveolar lavage (BAL) fluid from patients with sarcoidosis are activated. They are thought to recognize as yet unknown antigens and to play an important role in the pathogenesis of the disease. We studied the use of the T cell receptor V beta gene of lymphocytes obtained by BAL and lymphocytes obtained from peripheral blood of 11 patients with sarcoidosis and 9 normal controls, using the reverse transcriptase-polymerase chain reaction. As compared to the normal controls, V beta 2 and V beta 6 genes were predominantly expressed (> 15% of the sum of all V beta transcripts) on lymphocytes obtained from BAL fluid in 4 and 7 of 11 patients with sarcoidosis, respectively, but no specific V beta gene was predominantly expressed on lymphocytes obtained from peripheral blood. These results imply that those lymphocytes that are obtained from BAL fluid and that express V beta 2 and V beta 6 genes are involved in the pathogenesis of sarcoidosis.
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PMID:[Restricted T cell receptor V beta gene expression in bronchoalveolar lavage lymphocytes of patients with sarcoidosis]. 773 69

Sarcoidosis is a granulomatous disorder of unknown etiology. Accumulated data suggest that one or several exogenous or altered self antigens participate in producing pathophysiological change in sarcoidosis. Recently, analysis of retroviruses such as HTLV-1 and HIV-1 revealed that these viruses would produce autoimmune disease like symptoms including interstitial lung disease like pulmonary manifestation. We hypothesized novel type retrovirus or retrovirus related antigens might be a putative pathogen for sarcoidosis. Syncytial cell formation or cytopathic effect was observed in 6 of 24 patients (25%) after coculture of sarcoid BALF cells with U937 cells. Five of 18 culture supernatant showed moderate reverse transcriptase activity. Expression of clone 4-1 env protein, one of the endogenous retroviral elements, was also observed in alveolar macrophages of sarcoidosis. These data encourages the further investigation of retrovirus as the pathogen of sarcoidosis.
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PMID:[Retroviral infection as a putative pathogen for sarcoidosis]. 804 31

In pulmonary sarcoidosis or experimental granuloma formation, interleukin-1 beta (IL-1 beta) or tumor necrosis factor alpha (TNF-alpha) are considered to play important roles during inflammatory evolution. In order to examine whether IL-1 beta or TNF-alpha mRNA expression on lung macrophages relates to the disease activity or clinical course, ten cases with pulmonary sarcoidosis were divided into two groups: five cases who had a disease duration of more than 10 years (14.6 +/- 4.4 years; group A), and 5 cases with duration of less than 3 years (1.7 +/- 1.1 years; group B). All cases showed both abnormal radiographs and elevated serum angiotensin converting enzyme activities. We compared the 10 cases with 12 healthy individuals as normal control (6 nonsmokers: NS and 6 current smokers: S), and 5 cases with idiopathic pulmonary fibrosis (IPF) as disease control. Lavage macrophages were purified by rosette forming method and plastic adhesion was then performed for 1 hour. Thereafter mRNA was extracted by AGPC method and amplified by reverse transcriptase-polymerase chain reaction (RT-PCR) (20 cycles). The results showed that IL-1 beta mRNA was detected in all materials studied, but TNF-alpha mRNA expression was different among the groups: 5/5 (100%) in group A, 1/5 (25%) in group B, 5/5 (100%) in IPF, and 12/12 (100%) in normal controls. The absence of detection of TNF-alpha mRNA (rapid down regulation) in pulmonary sarcoidosis may relate to spontaneous regression, because a substantial number of cases in group B showed spontaneous regression in their natural course.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Differential detection of IL-1 beta and TNF-alpha mRNA on lung macrophages from patients with pulmonary sarcoidosis]. 825 14

Sarcoidosis is a systemic granulomatous disease of unknown etiology characterized by the pronounced accumulation of CD4+ T cells and macrophages in the affected organs. TCR variable (V) alpha and V beta gene usage in patients with sarcoidosis is still a matter of discussion. In this investigation, we analysed TCR-V alpha and -V beta gene usage in bronchoalveolar lavage fluid (BALF) and peripheral blood mononuclear cells (PBMC) of 30 patients with active pulmonary sarcoidosis using an adapter ligation method, reverse transcriptase-polymerase chain reaction (RT-PCR), and sequence-specific oligonucleotide probe (SSOP) analyses. There was no significant difference in TCR-V alpha or -V beta gene usage between BALF (n = 12) or PBMC (n = 27) of patients and PBMC of healthy subjects (n = 10). Neither selective TCR-V alpha nor -V beta expansion was observed in the paired BALF and PBMC from seven of nine patients. However, selective expansions were observed in a few TCR-V alpha or -V beta subsets in the BALF or PBMC of some individuals. Although a modest increase in a few TCR-V alpha or -V beta subsets was observed in the BALF or PBMC of some individuals, the increased TCR-V alpha or -V beta subsets were not closely associated with the HLA-DRB1, DQA1, DQB1, and DPB1 alleles of these patients. These results suggest that TCR-V alpha or -V beta gene usage is not restricted in both lung and peripheral blood in the majority of patients with active pulmonary sarcoidosis.
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PMID:Non-restricted T cell receptor (TCR)-V alpha and -V beta gene usage in patients with pulmonary sarcoidosis. 918 3

Our previous reports demonstrated the concomitant release of IL-1 beta and IL-1 inhibitory activity in the culture supernatants of BALF macrophages in both healthy subjects and patients with interstitial lung diseases. IL-1 inhibitory activities decreased in healthy smokers (HS), and patients with sarcoidosis (Sar), or idiopathic pulmonary fibrosis (IPF), compared with those in healthy nonsmokers (HNS), though an increase in IL-1 beta release was not detected. IL-1 inhibitory activity was mainly characterized as IL-1 receptor antagonist (IL-1ra). In this study, we confirmed a decrease in IL-1ra in terms of the amounts of protein (enzyme-linked immunoassay) and gene transcripts (reverse transcriptase polymerase chain reaction followed by high performance liquid chromatography). Imbalance between IL-1ra and IL-1 beta was expressed as a molar ratio of IL-1ra/IL-1 beta protein: (Sar; 4.20 +/- 2.06, IPF; 4.26 +/- 3.41, HS; 3.44 +/- 3.09 versus NS 8.33 +/- 2.77: P < 0.001). These results were similar in terms of the amounts of gene transcripts. In conclusion, the imbalance of IL-1 beta and IL-1ra production was confirmed at three levels: biological activity, amounts of protein, and gene transcript obtained from BALF macrophages in chronic inflammatory processes in the lungs.
Sarcoidosis Vasc Diffuse Lung Dis 1997 Mar
PMID:Quantitative evaluation of the IL-1 beta and IL-1 receptor antagonist obtained from BALF macrophages in patients with interstitial lung diseases. 918 88

Inducible nitric oxide synthase (iNOS) is required in immune response against infections and is involved in granuloma formation in animals; in murine macrophages, iNOS is induced by lipopolysaccharide and interferon-gamma. In contrast, the role of iNOS in human immune response against infections is still questioned, and its expression in granulomas is poorly investigated. Using Western blotting and immunohistochemistry, we investigated iNOS expression in human lymph nodes with nonspecific reactions and in tissues containing granulomas caused by mycobacteria, Toxoplasma, Cryptococcus neoformans, Leishmania, Bartonella, noninfectious granulomas (sarcoidosis, foreign body), and other hystiocitic reactions (Kikuchi's disease, Omenn syndrome). iNOS was undetectable in nonspecific reactive lymphadenitis, foreign-body granulomas, and Omenn syndrome, whereas it was strongly expressed in infectious granulomas, sarcoidosis, and Kikuchi's diseases. Immunohistochemistry demonstrated that iNOS was selectively expressed by the epithelioid and multinucleated giant cells within the granulomas. Use of an anti-nitrotyrosine antibody, recognizing nitrosilated amino acid residues derived from nitric oxide production, revealed a consistent positivity within the cells expressing iNOS, thus suggesting that iNOS is functionally active. Detection of cytokines by reverse transcriptase-polymerase chain reaction demonstrated that tissues that were positive for iNOS, also expressed the Thl-type cytokine interferon-gamma mRNA, but not the Th2-type cytokine interleukin-4. Taken together, these results indicate that iNOS is involved in different human immune reactions characterized by histiocytic/granulomatous inflammation and associated with Th1-type cytokine secretion.
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PMID:Expression of inducible nitric oxide synthase in human granulomas and histiocytic reactions. 991 29

Sarcoidosis is a chronic inflammatory disease of unknown aetiology characterized by the formation of non-necrotizing granulomas. The course of disease is usually self-limiting with the spontaneous resolution of granuloma. In the immune system, Fas antigen (Fas) and Fas ligand (FasL) are involved in the down regulation of immune reactions by inducing apoptosis. Therefore, it was hypothesized that the Fas/FasL pathway and apoptosis may be associated with the course of granulomatous inflammation in sarcoidosis. Terminal deoxynucleotidyl transferase-mediated biotin nick end-labelling (TUNEL) was performed to assess deoxyribonucleic acid strand breakages as a characteristic of apoptosis. Immunohistochemistry was also performed to detect Fas and FasL protein, and reverse transcriptase polymerase chain reaction (RT-PCR) and RT in situ PCR to detect FasL messenger ribonucleic acid (mRNA). Positive signals for TUNEL were detected in epithelioid histiocytes and lymphocytes within granulomas and in bronchoalveolar lavage (BAL) lymphocytes from patients with sarcoidosis. Positive signals for Fas were also detected in these cells. FasL mRNA was expressed in BAL lymphocytes from 15 of 20 patients with sarcoidosis, but from only one of 10 patients with normal lung parenchyma. FasL protein was expressed in lymphocytes surrounding and within the granuloma. There was a significant correlation between the result of TUNEL and clinical course in patients with sarcoidosis. Apoptosis in epithelioid histiocytes and inflammatory cells seems to participate in the course of granulomatous inflammation. Further studies are needed to determine the role of Fas, FasL and other regulatory factors in apoptosis in the granulomatous inflammation in pulmonary sarcoidosis.
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PMID:Apoptosis in the course of granulomatous inflammation in pulmonary sarcoidosis. 1044 8


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