Leukotoxin (LtxA/Leukothera) induces ATP expulsion via pannexin-1 channels and subsequent cell death in malignant lymphocytes
| Autor: | Deendayal Patel, Scott C. Kachlany, Derek J. Prince |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Cell death
Programmed cell death Necrosis Bacterial toxins Lymphoma Science Poly ADP ribose polymerase Exotoxins Apoptosis Nerve Tissue Proteins Jurkat cells Article Connexins Jurkat Cells chemistry.chemical_compound Adenosine Triphosphate medicine Humans Lymphocytes Caspase Multidisciplinary biology Chemistry Cell Membrane Bacteriology Phosphatidylserine Leukemia Lymphoid Cell biology Gene Knockdown Techniques biology.protein Medicine Calcium Receptors Purinergic P2X7 medicine.symptom Intracellular Signal Transduction |
| Zdroj: | Scientific Reports, Vol 11, Iss 1, Pp 1-14 (2021) Scientific Reports |
| ISSN: | 2045-2322 |
| DOI: | 10.1038/s41598-021-97545-4 |
| Popis: | Leukotoxin (LtxA) (Trade name, Leukothera) is a protein that is secreted from the oral bacterium Aggregatibacter actinomycetemcomitans, which targets and kills activated white blood cells (WBCs) by binding to lymphocyte function associated antigen-1 (LFA-1). Interaction between LtxA and Jurkat T-cells results in cell death and is characterized by increased intracellular Ca2+, activation of caspases, clustering of LtxA and LFA-1 within lipid rafts, and involvement of the Fas death receptor. Here, we show that LtxA can kill malignant lymphocytes via apoptotic and necrotic forms of cell death. We show that LtxA causes activation of caspases and PARP, cleavage of pannexin-1 (Panx1) channels, and expulsion of ATP, ultimately leading to cell death via apoptosis and necrosis. CRISPR-Cas9 mediated knockout (K/O) of Panx1 in Jurkat cells prevented ATP expulsion and resulted in resistance to LtxA for both apoptotic and necrotic forms of death. Resistance to necrosis could only be overcome when supplementing LtxA with endogenous ATP (bzATP). The combination of LtxA and bzATP promoted only necrosis, as no Panx1 K/O cells stained positive for phosphatidylserine (PS) exposure following the combined treatment. Inhibition of LtxA/bzATP-induced necrosis was possible when pretreating Jurkat cells with oATP, a P2X7R antagonist. Similarly, blockage of P2X7Rs with oATP prevented the intracellular mobilization of Ca2+, an important early step in LtxA induced cell death. We show that LtxA is able to kill malignant lymphocytes through an apoptotic death pathway which is potentially linked to a Panx1/P2X7R mediated necrotic form of death. Thus, inhibition of ATP release appears to significantly delay the onset of LtxA induced apoptosis while completely disabling the necrotic death pathway in T-lymphocytes, demonstrating the crucial role of ATP release in LtxA-mediated cell death. |
| Databáze: | OpenAIRE |
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