Professor David A. Fruman, Molecular Biology and Biochemistry, studies lymphocyte physiology for insights into immunological diseases and cancer.  Recent work from his lab, led by graduate student Lomon So, has identified a new molecular mechanism to explain how the immunosuppressant rapamycin achieves selective inhibition of lymphocyte growth and cell proliferation.  Their results may one day lead to more efficient immunosuppressant drugs.

In the current study, Professor Fruman and colleagues wanted to determine why the immunosuppressant, rapamycin, has a selective potency in lymphocytes.  They focused their attention on a key family of mammalian target of rapamycin (mTOR) substrates known as 4E-BPs.  They found that rapamycin could disrupt the phosphorylation of specific 4E-BPs found in lymphocytes, which led to suppression of lymphocyte growth and proliferation.  The results from Professor Fruman’s study may one day be used to make more potent immunosuppressant drugs for clinical use.

Other researchers who contributed to this work were: Jongdae Lee, Miguel Palafox, Sharmila Mallya, Chaz Woxland, Meztli Arguello, Morgan Truitt, Nahum Sonenberg and Davide Ruggero.  The complete study results can be found in the May edition of Science Signaling.