A novel exogenous retrovirus sequence identified in humans

Area of Science:

• Virology
• Molecular Biology
• Immunology

Background:

• Sjögren's syndrome is an autoimmune disorder affecting exocrine glands.
• The potential role of retroviruses in autoimmune diseases remains an area of investigation.

Purpose of the Study:

• To investigate the presence of novel retroviral sequences in patients with Sjögren's syndrome.
• To characterize the nature and origin of the identified retroviral sequence.

Main Methods:

• Reverse transcriptase PCR (RT-PCR) was used to amplify retroviral sequences from salivary gland tissue.
• Sucrose density gradient centrifugation was employed to isolate viral particles.
• PCR and Southern hybridization were used to detect the sequence in genomic DNA.

Main Results:

• A 932-bp retrovirus sequence, related to types B and D, was cloned from Sjögren's syndrome patient salivary glands.
• The sequence was found in fractions consistent with enveloped retroviral particles.
• High sequence similarity (>90%) was observed in tissues from multiple individuals, at low copy numbers (<1 per 10^3 cells).
• The sequence was not detected in human genomic DNA.

Conclusions:

• The findings suggest the identification of an infectiously acquired retroviral genome, termed human retrovirus 5 (HRV5).
• HRV5 may be associated with Sjögren's syndrome, warranting further investigation into its role in the disease pathogenesis.