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Exacerbation of human immunodeficiency virus infection in promonocytic cells by bacterial immunomodulators
K N Masihi1, W Lange, B Rohde-Schulz
1Robert Koch Institute, Federal Health Office, Berlin, F.R.G.
Abstract:
Common bacterial infections are increasingly being diagnosed in HIV-infected individuals. Cells of the monocyte-macrophage lineage kill invading bacterial pathogens and subsequently release immunoadjuvant components from the degraded cell walls. Since monocytes can be infected with HIV, effects of bacterial immunomodulators on infected promonocytic U937 cells were investigated. Synthetic muramyl peptide, mycobacterial trehalose dimycolate, and detoxified endotoxin exhibited an initial reduction followed by a rapid increase in HIV p24 antigen production. The upregulation of virus expression was correlated with enhanced interleukin-1 beta levels and a decrease in TNF-alpha production.
Insights
Bacterial immunomodulators can increase HIV replication in infected monocytes. This study found that components from bacterial cell walls boosted HIV p24 antigen production, linked to altered cytokine levels.
Area of Science:
- Immunology
- Virology
- Cell Biology
Background:
- HIV-infected individuals frequently develop bacterial infections.
- Monocyte-macrophage lineage cells combat bacteria but can be infected by HIV.
- Bacterial components can modulate immune responses.
Purpose of the Study:
- To investigate the effects of bacterial immunomodulators on HIV-infected promonocytic U937 cells.
- To understand how bacterial components influence HIV expression in monocytes.
Main Methods:
- Treatment of U937 cells (a human promonocytic cell line) with HIV.
- Exposure of HIV-infected U937 cells to synthetic muramyl peptide, mycobacterial trehalose dimycolate, and detoxified endotoxin.
- Measurement of HIV p24 antigen production, interleukin-1 beta (IL-1β), and tumor necrosis factor-alpha (TNF-α) levels.
Main Results:
- Bacterial immunomodulators initially reduced, then rapidly increased HIV p24 antigen production.
- Upregulation of HIV expression correlated with increased IL-1β levels.
- A decrease in TNF-α production was observed alongside enhanced viral expression.
Conclusions:
- Bacterial immunomodulators can exacerbate HIV replication in infected monocytes.
- The interplay between bacterial components, monocyte infection, and cytokine production impacts HIV pathogenesis.
- Further research is needed to explore therapeutic strategies targeting this interaction.