Retroviral expression in mononuclear blood cells isolated from a patient with osteopetrosis (Albers-Schönberg disease).
We report the presence of reverse transcriptase activity in the supernatant of long-term culture of mononuclear blood cells (monocytes and lymphocytes) isolated from a 27-year-old patient suffering from benign osteopetrosis. The enzyme was purified to homogeneity according to the technique of Chandra and Steel, by chromatography, first on DEAE-cellulose (DE 52) and then on phosphocellulose (P11). After purification, the enzyme was characterized biochemically for its template specificity and ionic requirements. The purified enzyme was able to transcribe poly(rA).(dT)12-18 and poly(rC).(dG)12-18 very efficiently and had a marked preference for Mg2+ ions over Mn2+ ions. The pattern of ionic dependency for this enzyme is similar to that of reverse transcriptases purified from human lymphotropic viruses. The patient was tested and found sero-negative for HIV-1, HIV-2, and HTLV-I and seropositive (immunoglobulin G) for cytomegalovirus. Epstein-Barr virus nuclear antigens (EBNA) were detected in the patient's B lymphocytes. Since reverse transcriptase is the hallmark of retroviruses, we suggest that a retrovirus may be involved in the etiology of osteopetrosis.
CNRS, Institut Biomédical des Cordeliers, Université Pierre et Marie Curie, Paris, France.
M L
ML
Labat
A F
AF
Bringuier
A
A
Chandra
T A
TA
Einhorn
P
P
Chandra
D000328:Adult; D002845:Chromatography; D005260:Female; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000201:enzymology / Q000382:microbiology*; D010022:Osteopetrosis / Q000201:enzymology / Q000209:etiology / Q000382:microbiology*; D011119:Polynucleotides; D012194:RNA-Directed DNA Polymerase / Q000097:blood; D012190:Retroviridae / Q000201:enzymology / Q000302:isolation & purification* / Q000472:pathogenicity; D013379:Substrate Specificity
D011119:Polynucleotides; D012194:RNA-Directed DNA Polymerase