Partial genome analysis of murine gammaherpesvirus 4556.

UNLABELLED: Murine gammaherpesvirus 68 (MHV-68) -infected mouse is an animal model of gammaherpesvirus infection in man and domestic animals. Murine gammaherpesvirus 4556 (MHV-4556), isolated from Apodemus flavicollis ticks has been considered a close relative of MHV-68 but different in some features of infection in vitro and in vivo. Previous comparison of MHV-4556 with MHV-68 has revealed their diversity in immune evasion protein MK3. In this study, HindIII and EcoRI restriction profiles of the MHV-4556 genome disclosed absence of the deletion that has been identified previously at the left end of genomes of murine gammaherpesvirus 76 (MHV-76) and murine gammaherpesvirus Sumava (MHV-Sumava). A 22, 565 bp portion of MHV-4556 genome sequence was sequenced, analyzed and compared with that of MHV-68. Nucleotide sequences of 21 genes of MHV-4556 and deduced amino acid sequences revealed their identity to those of MHV-68 except for differences in 15 nucleotides and 8 amino acids in 5 genes and their proteins, respectively. Due to these differences, immune evasion protein M4 and structural proteins encoded by ORF8 (gB), ORF11 (p43), ORF26 and ORF52, respectively, are predicted to have a reduced hydrophilicity and surface exposure compard with their MHV-68 counterparts. These differences obviously contribute to some different pathogenetical features of these viruses and could explain the weaker immunogenicity of MHV-4556 in comparison with MHV-68. KEYWORDS: murine gammaherpesvirus 4556; restriction analysis; partial genome sequence.

Partial genome sequence of murine gammaherpesvirus 72 and its analysis.

Murine gammaherpesvirus 68 (MHV-68)-infected mouse is a well known model for studies of Epstein-Barr virus (EBV)-related lymphoproliferative diseases (LPD). Murine gammaherpesvirus 72 (MHV-72) has been considered a close relative of MHV-68 but its replication in murine mammary gland cells and kinetics of infection of mice were found to be different. Pathological studies of a long-term-infection of mice revealed a similar or higher malignancy development rate in MHV-72-infected mice as compared with that of MHV-68. Previous comparison of MHV-72 with MHV-68 revealed their diversity in M3, MK3, and M7 genes encoding the chemokine-binding protein, immune evasion protein and glycoprotein 150, respectively. In this study, a portion (22,899 bp) of MHV-72 genome sequence was determined, analyzed and compared with that of MHV-68. Nucleotide sequences of 13 structural and 6 non-structural genes of MHV-72 and deduced amino acid sequences revealed their identity to those of MHV-72 except for differences in 9 nucleotides and 8 amino acids, occurring in 5 genes and their proteins. Due to these differences, 4 structural proteins encoded by ORF20, ORF26, ORF48, and ORF52, respectively, and a non-structural protein encoded by ORF4, all of MHV-72, are predicted to have altered hydrophilicity and surface exposure in comparison with their MHV-68 counterparts. These differences obviously contribute to some different pathogenetical features of these viruses and could explain the reduced immunogenicity of MHV-72 in relation to MHV-68, allowing MHV-72 to escape the host immune surveillance.

Occurrence of human papillomavirus 16 and 18 in smears from the two cervix regions of onco-gynecological patients in Slovakia.

We evaluated the relevance of tests for Human papillomavirus 16 and 18 (HPV-16, HPV-18) in two cervix regions (exocervical and endocervical) separately. The total of 142 cervical smears obtained from 91 women in Slovakia attending onco-gynecological outpatient care were examined for the presence of HPVs by PCR with the general primers GP5 and GP6 (GP5/6). The HPV-positive smears were examined for the presence of HPV-16 and HPV-18 and the results compared with cytological assessment. In 73 HPV-positive smears, the number of cases with detected HPV-16 was about three times higher in exocervix and about two times higher in endocervix in comparison with number of cases with detected HPV-18. In the smears considered as normal by cytology, two times higher occurrence of HPV-18 in endocervical smears was found in comparison with exocervical ones. Eight patients were double-infected with HPV-16 and HPV-18, but no patient was infected with these HPVs in both cervical regions. This finding emphasized the importance of examination of both cervical regions separately. Overlooking of the endocervical canal for the close examination by cytology and PCR might increase the failure to detect HPVs associated with adenocarcinoma.