Grants Awarded

M1 Versus M2 Polarization of the Hemophagocyte: Insight into Biologic Function

Principal Investigator
Edward Behrens MD
The Children’s Hospital of Philadelphia – Philadelphia, Pennsylvania USA

Date of Award
December 2012

Amount of Award

Layperson Summary
Hemophagocytic syndromes are a rapidly fatal subset of histiocytic disorders that occur in a wide variety of
clinical scenarios in both children and adults. As the name implies, they are characterized by the appearance
of the hemophagocyte, an immune cell that is seen to be eating other blood cells in the body. Despite the
central importance of this cell in naming the syndrome, very little is actually understood about what
hemophagocytes are contributing to the disease. Competing ideas have been proposed, some suggesting that
hemophagocytes are causing many elements of the disease, and opposing suggestions that these cells may
actually be an ineffectual attempt to try to control inflammation and may therefore be helpful. Knowing which of
these hypotheses is correct is important to the treatment of hemophagocytic syndrome, since therapy could be
tailored to either eliminate or enhance these cells depending on their functions. This would lead to better
rational therapies for this important subset of histiocytic disorders. This project seeks to determine the function
of hemophagocytes by looking at which genes are active in these cells, and by studying which proteins they
express in order to understand their “biologic program”. These data will allow us to determine whether these
cells are inflammatory and should be eliminated, or if they are regulatory, and maybe beneficial to the patient.

Twelve Month Report