Honyin Chiu earned her B.S. in Biochemistry and Molecular Biology from UC San Diego in 2010. Before starting her PhD studies, she previously worked at biotech companies such as TriLink Biotechnologies in San Diego and BioRad in Irvine. She first decided to pursue an M.S. degree in Biotechology from UC Irvine and then continued for her PhD at UCI.
Honyin’s training in immunology began when she first started studying the signaling mechanisms promoting T cell death in the context of immune tolerance during her Master’s research in Dr. Craig Walsh’s lab. She then continued her studies in Dr. David Fruman’s lab and is currently interested in how immune B cells respond to signals to differentiate and promote an appropriate antibody response as well as finding new targeted therapies for antibody-driven autoimmune diseases.
mTOR signaling regulates the immune response and is highly activated in both human patient lymphocytes and B cells from lupus animal mouse models. However, little is known about the role of mTOR and its substrates in B cell differentiation and production of antibodies driving disease pathogenesis. Her preliminary data show that partial mTORC1 inhibition decreases class switching in vitro while minimally affecting proliferation of B cells. Mechanistic studies focusing on mTORC1 substrates show that 4E-BPs are inhibitory to antibody class switching. Since 4E-BPs interfere with eIF4E function in the mRNA cap-binding complex, these studies suggest that mTORC1 regulated cap-dependent translation may be a novel mechanism of controlling the antibody response. Thus, the goal of her project is to determine if activity of the cap-binding initiation factor eIF4E is important for antibody class switching. This study will not only illustrate how mTOR signaling is involved in B cell differentiation but may also potentially lead to new therapies for antibody driven autoimmune diseases such as SLE.
Limon JJ, So L, Jellbauer S, Chiu H, Corado J, Sykes SM, Raffatellu M, Fruman DA. (2014) mTOR kinase inhibitors promote antibody class switching via mTORC2 inhibition. Proc. Natl. Acad. Sci. U S A. 111: E5076-85
Chiu H, Mallya S, Nguyen P, Mai A, Fruman DA. (2017) The selective p110δ inhibitor IPI-3063 potently suppresses B cell function. Frontiers in Immunology. In Revision
Honors and Awards:
2016-2017 NIH T32 UC Irvine Immunology Research Training Grant
October 2016 American Association of Immunologists Young Investigator Award, La Jolla Immunology Conference
January 2017 Oral Presentation: “A Novel Role for the 4E-BP/eIF4E Axis in B Cell Antibody Class Switching.” Keystone Symposium: PI3K Pathways in Immunology, Growth Disorders and Cancer, Santa Fe, New Mexico