Meet the Scholars

Updated: April 21, 2014

Gregory Tietjen

Gregory Tietjen

CBC Scholar: Class of 2012
PhD Candidate, Program in Biophysical Sciences, UChicago;
Joint Advisors: Ka Yee Lee (Department of Chemistry) and Erin Adams (Department of Biochemistry and Molecular Biology)


On July 17, 2013, Greg successfully defended his thesis, entitled: "Immune Recognition of Phosphatidylserine by the Tim Proteins: A Multidisciplinary Study." Congratulations!



The immune system recognizes a vast array of chemical signatures as antigens although historically most research has focused more exclusively on protein/ protein recognition. More recently it has been appreciated that lipids can also be a potent stimulus for an immune response, both in the context of lipid- presenting molecules (CD1), and as a component of the cell’s plasma membrane (phosphatidylserine receptors). I am studying the molecular mechanisms by which a family of 3 unique phosphatidylserine receptors (Tim family) can directly recognize “out of context” components of the lipid membrane and how this recognition process then stimulates an appropriate immune response. To elucidate the molecular specifics of how the Tims recognize immunogenic cellular membranes, I am utilizing a novel combination of X-ray Reflectometry and Molecular Dynamic Simulations. In addition to basic structural information, I am also endeavoring to determine both the strength and specificity of these interactions for each individual Tim family member with the goal of illuminating their individual roles in the immune response to phosphatidylserine exposure.



Tietjen GT, Gong Z, Chen CH, Vargas E, Crooks JE, Cao KD, Heffern CT, Henderson JM, Meron M, Lin B, Roux B, Schlossman ML, Steck TL, Lee KY, Adams EJ. Molecular mechanism for differential recognition of membrane phosphatidylserine by the immune regulatory receptor Tim4. Proc Natl Acad Sci U S A. 2014 Apr 15;111(15):E1463-72. (PubMed)

Tietjen GT, Kong Y, Parthasarathy R. An efficient method for the creation of tunable optical line traps via control of gradient and scattering forces. Opt Express. 2008 Jul 7;16(14):10341-8. (PubMed)



  • Judge, Chicago Public Schools Student Science Fair, March 2012
  • Chicago Biomedical Consortium Scholarship, 2012-2013
  • 2009 and 2010 NSF Graduate Research Fellowship Honorable Mention



  • Program in Biophysical Sciences Peer Mentor
  • Summer 2011 – Summerlink Research Program Mentor
  • Summer 2010 – Incremental Mentoring Program Dreyfus Foundation Chemistry Outreach Grant: Program developer and mentor
  • Winter 2009 – Summer 2010 LMSA/MRSEC Research Program Mentor