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Effects of Bacterial Endotoxins on the Toxicity of Extracellular Histones to Mammalian Cells
Author(s) -
Burris Deon,
Sharma Lokesh,
Mantell Lin
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.718.3
Subject(s) - histone , viability assay , extracellular , lipopolysaccharide , trypan blue , cell , biology , microbiology and biotechnology , biochemistry , immunology , dna
During Bacterial infections, endotoxins are released from the bacterial cell wall and histones from damaged host cells into the extracellular milieu. Extracellular histones are known to act as potent bactericides against a wide range of pathogens. Additionally, deleterious effects of histones on mammalian cells were recently reported. Unpublished data from our lab show that the bactericidal effects of histones can be blocked by the presence of bacterial lipopolysaccharide (LPS). However, the effects of LPS on histone toxicity to the viability of mammalian cells are unknown. Using macrophage‐like RAW 264.7 cells, we studied the effects of extracellular histone in the presence of LPS on host macrophages. We used Trypan blue exclusion and MTT assays as indicators of cell viability. In accordance to previous studies, a substantial decrease in cell viability was found in cells treated for 24 h with histone alone. However, simultaneous treatment with LPS significantly blocked histone‐induced cell death. These results demonstrate that co‐treatment of extracellular histone with bacterial endotoxin decreases its detrimental effects on cell viability; suggesting, bacterial products may interfere with histone‐mediated cell death. We are currently investigating potential mechanisms underlying these observations. These studies give new insights on host‐pathogen interactions during infections.