Hemolysin induces Toll-like receptor (TLR)-independent apoptosis and multiple TLR-associated parallel activation of macrophages
| Autor: | Pallavi Banerjee, Kalyan K. Banerjee, Deep Chandan Chakraborty, Gayatri Mukherjee, T. K. Biswas |
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| Rok vydání: | 2011 |
| Předmět: |
Time Factors
Immunology Apoptosis Biology Hemolysin Proteins Biochemistry Mice Bacterial Proteins Animals CD40 Antigens Molecular Biology Caspase 7 Toll-like receptor Mice Inbred C3H TOLLIP Macrophages Cell Biology Molecular biology Caspase 9 Toll-Like Receptor 2 Cell biology Mitochondria Mice Inbred C57BL Toll-Like Receptor 4 TLR2 Toll-Like Receptor 6 Jacalin TLR4 Cytolysin B7-2 Antigen Cell activation |
| Zdroj: | The Journal of biological chemistry. 286(40) |
| ISSN: | 1083-351X |
| Popis: | Vibrio cholerae hemolysin (HlyA) displays bipartite property while supervising macrophages (MΦ). The pore-forming toxin causes profound apoptosis within 3 h of exposure and in parallel supports activation of the defying MΦ. HlyA-induced apoptosis of MΦ remains steady for 24 h, is Toll-like receptor (TLR)-independent, and is driven by caspase-9 and caspase-7, thus involving the mitochondrial or intrinsic pathway. Cell activation is carried forward by time dependent up-regulation of varying TLRs. The promiscuous TLR association of HlyA prompted investigation, which revealed the β-prism lectin domain of HlyA simulated TLR4 up-regulation by jacalin, a plant lectin homologue besides expressing CD86 and type I cytokines TNF-α and IL-12. However, HlyA cytolytic protein domain up-regulated TLR2, which controlled CD40 for continuity of cell activation. Expression of TOLLIP before TLR2 and TLR6 abrogated TLR4, CD40, and CD86. We show that the transient expression of TOLLIP leading to curbing of activation-associated capabilities is a plausible feedback mechanism of MΦ to deploy TLR2 and prolong activation involving CD40 to encounter the HlyA cytolysin domain. |
| Databáze: | OpenAIRE |
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