Human Herpesvirus 7 is a T-Lymphotropic Virus and is Related to, but Significantly Different from, Human Herpesvirus 6 and Human Cytomegalovirus

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 89; no. 21; pp. 10552 - 10556
• Main Authors: Berneman, Zwi N., Ablashi, Dharam V., Li, Ge, Eger-Fletcher, Maureen, Reitz, Marvin S., Hung, Chia-Ling, Brus, Irena, Komaroff, Anthony L., Gallo, Robert C.
• Format: Journal Article
• Language: English
• Published: Washington, DC National Academy of Sciences of the United States of America 01.11.1992; National Acad Sciences; National Academy of Sciences
• Subjects: Amino Acid Sequence; Base Sequence; Biological and medical sciences; Blotting, Southern; CD4 Antigens - immunology; CD8 Antigens - immunology; Cell Line; Cell lines; Chronic fatigue syndrome; Cloning, Molecular; Cytomegalovirus - classification; Cytomegalovirus - genetics; DNA; DNA Probes; DNA, Viral - genetics; Fluorescent antibody techniques; Fundamental and applied biological sciences. Psychology; Genetics; Herpes viruses; Herpesvirus 6, Human - classification; Herpesvirus 6, Human - genetics; Herpesvirus 7, Human - classification; Herpesvirus 7, Human - genetics; Human herpesvirus 6; Human herpesvirus 7; Humans; Lymphatic system; Medical research; Microbiology; Molecular Sequence Data; Oligodeoxyribonucleotides; Polymerase chain reaction; Polymerase Chain Reaction - methods; Sequence Homology, Amino Acid; Sequence Homology, Nucleic Acid; T lymphocytes; T-Lymphocytes - microbiology; Virology; Viruses; Virus; Human; Tropism; Molecular hybridization; Herpesviridae; DNA; Sequence alignment; T-Lymphocyte; Homology; Molecular probe; Clinical isolate; Cell subpopulation
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.89.21.10552

An independent strain (JI) of human herpesvirus 7 (HHV-7) was isolated from a patient with chronic fatigue syndrome (CFS). No significant association could be established by seroepidemiology between HHV-7 and CFS. HHV-7 is a T-lymphotropic virus, infecting CD4+and CD8+primary lymphocytes. HHV-7 can also infect SUP-T1, an immature T-cell line, with variable success. Southern blot analysis with DNA probes scanning 58.8% of the human herpesvirus 6 (HHV-6) genome and hybridizing to all HHV-6 strains tested so far revealed homology to HHV-7 with only 37.4% of the total probe length. HHV-7 contains the GGGTTA repetitive sequence, as do HHV-6 and Marek's disease chicken herpesvirus. DNA sequencing of a 186-base-pair fragment of HHV-7(JI) revealed an identity with HHV-6 and human cytomegalovirus of 57.5% and 36%, respectively. Oligonucleotide primers derived from this sequence (HV7/HV8, HV10/HV11) amplified HHV-7 DNA only and did not amplify DNA from other human herpesviruses, including 12 different HHV-6 strains. Southern blot analysis with the p43L3 probe containing the 186-base-pair HHV-7 DNA fragment hybridized to HHV-7 DNA only. The molecular divergence between human cytomegalovirus, on the one hand, and HHV-6 and HHV-7, on the other, is greater than between HHV-6 and HHV-7, which, in turn, is greater than the difference between HHV-6 strains. This study supports the classification of HHV-7 as an additional member of the human β-herpesviruses.