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Virus-like particles with reverse transcriptase activity associated with Kawasaki disease
1Department of Medical Research, Veterans General Hospital-Taipei, Taiwan, Republic of China.
Abstract:
To investigate the etiologic agent associated with Kawasaki disease (KD), we initially established a cocultivation system using concanavalin A (Con A)-stimulated lymphoblastoid cells obtained from each retrovirus-seronegative individual's peripheral blood mononuclear cells (MNCs) cocultivated with each of 1) 40 patients with KD, 2) 10 patients with other viral infection and skin rash, and 3) 10 age- and sex-matched normal controls. Five major findings suggested that virus-like particles with reverse transcriptase (RT) activity are associated with KD. First, RT activity appeared significantly higher on day 12 after the onset of fever in the KD patients than in those with other viral infections and normal controls (dTMP incorporation: 3,645 +/- 248 vs. 434 +/- 50 vs. 412 +/- 46 cpm, P < 0.0001). Second, the RT activity was not endogenous, because the Con A-stimulated lymphoblastoid cells were obtained from the individuals who were negative for retrovirus. Third, virus-like particles (80-100 nm in diameter) by electron microscopy were found in the concentrated pool supernatants of particulate fraction containing RT activity subjected to sucrose density gradient, obtained from KD patients. Fourth, the viral product, a 31.4 kilodalton molecule, was detected by SDS-PAGE after internal labelling (methionine-S35) and density gradient centrifugation. Fifth, using a "retrovirus universal pol gene region" as a primer and the RT-PCR method, a retrovirus-specific band was detected in the cocultivated supernatants obtained from four KD and one AIDS patients but not in patients with rubella or in healthy controls.(ABSTRACT TRUNCATED AT 250 WORDS)
Insights
Researchers found virus-like particles with reverse transcriptase activity in Kawasaki disease (KD) patients, suggesting a potential retroviral link to this illness.
Area of Science:
- Virology
- Immunology
- Pediatric Infectious Diseases
Background:
- Kawasaki disease (KD) is an acute febrile illness of unknown etiology primarily affecting young children.
- Previous research has explored infectious agents, including viruses, as potential triggers for KD.
- The role of retroviruses in KD pathogenesis remains largely uninvestigated.
Purpose of the Study:
- To investigate the potential etiologic agent, specifically retroviruses, associated with Kawasaki disease.
- To establish a cocultivation system to detect virus-like particles and associated enzymatic activity in KD patients.
Main Methods:
- Cocultivation of concanavalin A-stimulated lymphoblastoid cells from retrovirus-seronegative individuals with cells from KD patients, other viral infection patients, and controls.
- Measurement of reverse transcriptase (RT) activity, electron microscopy for virus-like particles, SDS-PAGE for viral products, and RT-PCR for retroviral gene detection.
Main Results:
- Significantly higher RT activity was observed in KD patients compared to controls (P < 0.0001).
- Virus-like particles (80-100 nm) and a 31.4 kDa viral product were identified in KD patient samples.
- Retrovirus-specific DNA sequences were detected in KD patients using RT-PCR.
Conclusions:
- The findings suggest an association between virus-like particles with reverse transcriptase activity and Kawasaki disease.
- These results point towards a potential retroviral etiology for Kawasaki disease.
- Further investigation is warranted to confirm the role of retroviruses in KD pathogenesis.