Increased expression of human herpesvirus 7 in lymphoid organs of AIDS patients.
BACKGROUND
Human herpesvirus 7 (HHV-7) interferes reciprocally with the human immunodeficiency virus (HIV) in CD4 T lymphocytes, as infection with HIV results in a down modulation of the CD4 molecule and inhibition of replication of HHV-7, and vice versa. Correlations between HHV-7 and HIV at the organ level have not been studied in detail.


OBJECTIVE
To study the presence and cellular distribution of HHV-7 in lymphoid organs, i.e. lymph nodes (LNs) and spleen in AIDS patients and HIV-seronegative individuals.


METHODS
Cross-sectional study. The detection of HHV-7 specific antigen pp85, the 85 kDa encoded tegument phosphoprotein by U14 gene, was performed by immunohistochemistry (IHC) with a well characterized monoclonal antibody (mAb 5E1) to pp85. Nested polymerase chain reaction (PCR) was applied to detect HHV-7 specific DNA sequences.


RESULTS
Cells infected with HHV-7 were detected in five of seven LNs from AIDS patients and in one of five LNs from HIV-seronegative patients. The infected cells were mainly macrophages. In samples from HIV-seropositive patients, a significantly higher number of HHV-7 infected cells could be observed than in specimens from HIV-seronegative patients. Neither the antigen nor DNA sequences of HHV-7 could be detected in spleen tissue from HIV-seronegative and AIDS patients.


CONCLUSIONS
The data indicate that HHV-7 undergoes a higher extent of reactivation from latency and/or of replication under immunosuppression due to HIV-infection, similar to the other beta-herpesviruses HHV-6 and human cytomegalovirus (HCMV). The data further suggest that LNs, but not the spleen, may be a site of latency and consequently of reactivation of HHV-7 in AIDS patients.
Kempf
W
W
Department of Dermatology, University Hospital Zurich, Gloriastrasse 31, CH-8091, Zurich, Switzerland. wkempf@hotmail.com
Müller
B
B
Maurer
R
R
Adams
V
V
Campadelli Fiume
G
G
D000163:Acquired Immunodeficiency Syndrome / Q000821:virology*; D000911:Antibodies, Monoclonal; D000956:Antigens, Viral / Q000096:biosynthesis* / Q000276:immunology; D003430:Cross-Sectional Studies; D004279:DNA, Viral / Q000032:analysis; D018023:HIV Seronegativity; D006566:Herpesviridae Infections / Q000821:virology; D016199:Herpesvirus 7, Human / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D007150:Immunohistochemistry; D008198:Lymph Nodes / Q000821:virology*; D010750:Phosphoproteins / Q000096:biosynthesis / Q000276:immunology; D016133:Polymerase Chain Reaction; D013154:Spleen / Q000821:virology*; D017735:Virus Latency
D000911:Antibodies, Monoclonal; D000956:Antigens, Viral; D004279:DNA, Viral; D010750:Phosphoproteins