Isolation and purification of a non-A, non-B hepatitis-associated microtubular aggregates protein

Abstract

Blood-borne type non-A, non-B (NANB) hepatitisassociated microtubular aggregates protein was isolated and partially sequenced. The microtubular aggregates were isolated from the hepatocytes of NANBinfected chimpanzees and were found to have a buoyant density in sucrose solution of 1.21 to 1-23 g/ml. A single protein, recognized by our anti-microtubular aggregates monoclonal antibodies, was found to have an M~ of 44 000 (p44). This p44 protein was not found in uninfected chimpanzees. We determined a partial amino acid sequence for p44, and showed that it has no homology to any known proteins.

Enhanced Expression of Interferon-Regulated Genes in the Liver of Patients with Chronic Hepatitis C Virus Infection: Detection by Suppression-Subtractive Hybridization

“…Increased expression within the original tester material was checked by quantitative competitive RT-PCR, a technique which had been established using primer pairs designed on the basis of the database entries (Table 1). Relative to the reference tran-scripts glyceraldehyde-3-phosphate dehydrogenase (G3PDH, ␤-actin, and albumin, and compared to the original driver RNA preparation, transcripts of four genes were found to be elevated severalfold in the tester material (Table 2): (i) the chemokine IP-10 gene, originally described as an IFN-␥-inducible early-response gene (26,48); (ii) the IFN-␣-regulated antiviral MxA gene (1,40); (iii) the gene encoding the IFN-␣/␤-inducible 44-kDa microtubular polypeptide (p44) formerly shown to be associated with cytoplasmic ultrastructural entities in hepatocytes of chimpanzees inoculated with sera from patients suffering from non-A, non-B hepatitis (21,24,27,46); and (iv) the gene encoding the IFN-␣/␤/␥-inducible 56-kDa protein (IFI-56K) recently described to interact with the eukaryotic translation initiation factor eIF-3 (7, 50). The differential screening hybridization showed that all clones represents low-abundance transcripts in the HCV-infected liver, since they were detectable with the labeled subtracted probe but not with the labeled tester probe (data not shown).…”

“…The application of SSH to liver tissue from patients with chronic HCV infection as tester and non-HCV-infected patients as driver, the subsequent screening procedure, and the confirmatory controls revealed four genes which are expressed within the HCV-infected tissue to a higher degree than the noninfected control: (i) the CXC or alpha chemokine IP-10 gene (26,48), (ii) the antiviral MxA gene (1,40), (iii) a gene encoding a 44-kDa protein reported to be associated with ultrastructural changes in hepatocytes of chimpanzees infected with non-A, non-B hepatitis sera (21,24,27,46), and (iv) a gene encoding 56-kDa interferon-inducible protein which was recently shown to interact with eIF-3 (7,50). All of these genes are inducible by IFN-␥ (IP-10), IFN-␣/␤ (MxA and p44), or both (IFI-56K).…”

Epstein-Barr Virus-Induced Changes in B-Lymphocyte Gene Expression

“…LMP1 up-regulates expression of vimentin intermediate filaments, a p55 actin bundling protein, MARCKS, LFA-1, LFA-3, and ICAM-1 (10,13,47,101,106,107,(114)(115)(116). GS3686, the most highly EBV-induced mRNA, encodes a putative microtubule aggregating protein (43,103). PSCDBP binds to cytoadhesin 1 (61), and BASP1 is an N-terminally myristolated, Ca ϩ and calmodulin binding protein found in plasma membrane microdomains.…”

Delta hepatitis: molecular biology and clinical and epidemiological features

“…Shimizu et al (182) developed from human lymphocytes a monoclonal antibody that immunoreacted with liver biopsy material obtained from both HDV-and HCV-infected animals (183). The monoclonal antibody detects the presence of microtubule aggregates that apparently are synthesized in response to HDV or HCV infection (98,197).…”