Stressed erythrophagocytosis induces immunosuppression during sepsis through heme-mediated STAT1 dysregulation
Tolani F. Olonisakin, … , Prabir Ray, Janet S. Lee
Tolani F. Olonisakin, … , Prabir Ray, Janet S. Lee
Published September 17, 2020
Citation Information: J Clin Invest. 2021;131(1):e137468. https://doi.org/10.1172/JCI137468.
View: Text | PDF
Research Article Infectious disease Pulmonology

Stressed erythrophagocytosis induces immunosuppression during sepsis through heme-mediated STAT1 dysregulation

Abstract

Macrophages are main effectors of heme metabolism, increasing transiently in the liver during heightened disposal of damaged or senescent RBCs (sRBCs). Macrophages are also essential in defense against microbial threats, but pathological states of heme excess may be immunosuppressive. Herein, we uncovered a mechanism whereby an acute rise in sRBC disposal by macrophages led to an immunosuppressive phenotype after intrapulmonary Klebsiella pneumoniae infection characterized by increased extrapulmonary bacterial proliferation and reduced survival from sepsis in mice. The impaired immunity to K. pneumoniae during heightened sRBC disposal was independent of iron acquisition by bacterial siderophores, in that K. pneumoniae mutants lacking siderophore function recapitulated the findings observed with the WT strain. Rather, sRBC disposal induced a liver transcriptomic profile notable for suppression of Stat1 and IFN-related responses during K. pneumoniae sepsis. Excess heme handling by macrophages recapitulated STAT1 suppression during infection that required synergistic NRF1 and NRF2 activation but was independent of heme oxygenase-1 induction. Whereas iron was dispensable, the porphyrin moiety of heme was sufficient to mediate suppression of STAT1-dependent responses in human and mouse macrophages and promoted liver dissemination of K. pneumoniae in vivo. Thus, cellular heme metabolism dysfunction negatively regulated the STAT1 pathway, with implications in severe infection.

Authors

Tolani F. Olonisakin, Tomeka Suber, Shekina Gonzalez-Ferrer, Zeyu Xiong, Hernán F. Peñaloza, Rick van der Geest, Yuting Xiong, David O. Osei-Hwedieh, Jesús Tejero, Matthew R. Rosengart, Wendy M. Mars, Daria Van Tyne, Andreas Perlegas, Samuel Brashears, Daniel B. Kim-Shapiro, Mark T. Gladwin, Michael A. Bachman, Eldad A. Hod, Claudette St. Croix, Yulia Y. Tyurina, Valerian E. Kagan, Rama K. Mallampalli, Anuradha Ray, Prabir Ray, Janet S. Lee

×
Problems with a PDF?

This file is in Adobe Acrobat (PDF) format. If you have not installed and configured the Adobe Acrobat Reader on your system.

Having trouble reading a PDF?

PDFs are designed to be printed out and read, but if you prefer to read them online, you may find it easier if you increase the view size to 125%.

Having trouble saving a PDF?

Many versions of the free Acrobat Reader do not allow Save. You must instead save the PDF from the JCI Online page you downloaded it from. PC users: Right-click on the Download link and choose the option that says something like "Save Link As...". Mac users should hold the mouse button down on the link to get these same options.

Having trouble printing a PDF?

  1. Try printing one page at a time or to a newer printer.
  2. Try saving the file to disk before printing rather than opening it "on the fly." This requires that you configure your browser to "Save" rather than "Launch Application" for the file type "application/pdf", and can usually be done in the "Helper Applications" options.
  3. Make sure you are using the latest version of Adobe's Acrobat Reader.

supplemental data - Download (3.71 MB)

Advertisement