Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The two Epstein-Barr virus (EBV) types, EBV-1 and EBV-2, are known to differ in their EBNA-2 genes, which are 64 and 53% identical in their nucleotide and predicted amino acid sequences, respectively. Restriction endonuclease maps and serologic analyses detect few other differences between EBV-1 and EBV-2 except in the EBNA-3 gene family. We determined the DNA sequence of the AG876 EBV-2 EBNA-3 coding region and have compared it with known B95-8 EBV-1 EBNA-3 sequences to delineate the extent of divergence between EBV-1 and EBV-2 isolates in their EBNA-3 genes. The B95-8 and AG876 EBV isolates had nucleotide and amino acid identity levels of 90 and 84%, 88 and 80%, and 81 and 72% for the EBNA-3A, -3B, and -3C genes, respectively. In contrast, nucleotide sequence identity in the noncoding DNA adjacent to the B95-8 and AG876 EBNA-3 open reading frames was 96%. We used the polymerase chain reaction to demonstrate that five additional EBV-1 isolates and six additional EBV-2 isolates have the type-specific differences in their EBNA-3 genes predicted from the B95-8 or AG876 sequences. Thus, EBV-1 and EBV-2 are two distinct wild-type EBV strains that have significantly diverged at four genetic loci and have maintained type-characteristic differences at each locus. The delineation of these sequence differences between EBV-1 and EBV-2 is essential to ongoing molecular dissection of the biologic properties of EBV and of the human immune response to EBV infection. The application of these data to the delineation of epitopes recognized in the EBV-immune T-cell response is also discussed.
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PMID:Epstein-Barr virus types 1 and 2 differ in their EBNA-3A, EBNA-3B, and EBNA-3C genes. 216 6

Epstein-Barr virus (EBV) is often associated with lethal lymphoproliferative diseases in immunologically compromised individuals. Recently, we have studied a 20-month-old boy with X-linked lymphoproliferative disease (XLP) who had succumbed to infectious mononucleosis (IM) complicated by fulminant hepatitis and virus-associated hemophagocytic syndrome following EBV infection. EBV genomes were detected in peripheral blood lymphocytes (PBL), cervical and mesenteric lymph nodes, liver, spleen, thymus, and bone marrow. According to restriction endonuclease analyses, the EBV-DNA pattern was similar in all samples except for the EBV-DNA from the bone marrow. Additionally, circular EBV-DNA (suggesting a latent infection) predominated in spontaneously established lymphoblastoid cell lines (LCLs) derived from both the lymph node and cord lymphocytes co-cultured with PBL. In contrast, both circular and linear EBV-DNA (suggesting a lytic infection) were noted in spontaneously established LCLs derived from his PBL. Furthermore, LCLs derived from both the lymph node and cord lymphocytes co-cultured with PBL expressed fewer reactive cells for early antigen (EA) and viral capsid antigen (VCA) than spontaneous LCLs from his PBL, thus providing evidence for different B cellular susceptibility to EBV infection in this patient with XLP. Finally, defective EBV-specific cytotoxic T cell activity was observed in this patient. Latent EBV infected cells may easily escape immunosurveillance by the host. These findings may explain the fatal course of EBV infection in this patient.
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PMID:Differential cellular susceptibility to Epstein-Barr virus infection in a patient with X-linked lymphoproliferative disease. 217 37