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The Expression of HMGB 1 on Microparticles from Jurkat and HL ‐60 Cells Undergoing Apoptosis in vitro
Author(s) -
Spencer D. M.,
Mobarrez F.,
Wallén H.,
Pisetsky D. S.
Publication year - 2014
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1111/sji.12191
Subject(s) - jurkat cells , apoptosis , hmgb1 , microbiology and biotechnology , staurosporine , programmed cell death , flow cytometry , western blot , chemistry , biology , t cell , signal transduction , inflammation , biochemistry , immunology , immune system , protein kinase c , gene
Abstract HMGB 1 is a highly conserved nuclear protein that displays important biological activities inside as well as outside the cell and serves as a prototypic alarmin to activate innate immunity. The translocation of HMGB 1 from inside to outside the cell occurs with cell activation as well as cell death, including apoptosis. Apoptosis is also a setting for the release of cellular microparticles ( MP s), which are small membrane‐bound vesicles that represent an important source of extracellular nuclear molecules. To investigate whether HMGB 1 released from cells during apoptosis is also present on MP s, we determined the presence of HMGB 1 on particles released from Jurkat and HL ‐60 cells induced to undergo apoptosis in vitro by treatment with either etoposide or staurosporine; MP s released from cells undergoing necrosis by freeze–thaw were also characterized. As shown by both Western blot analysis and flow cytometry, MP s from apoptotic cells contain HMGB 1, with binding by antibodies indicating an accessible location in the particle structure. These results indicate that HMGB 1, like other nuclear molecules, can translocate into MP s during apoptosis and demonstrate another biochemical form of this molecule that may be immunologically active.