Much of Professor Kaplan’s work has focused on understanding the function of transcription factors in the development of T helper cell subsets. He has a long standing interest in Signal Transducer and Activator of Transcription or STAT proteins that are activated downstream of cytokines. His more recent work has made great progress towards understanding the development and function of IL-9-secreting T cells in the development of allergic inflammation. Ongoing interests lie in understanding how T cell subsets contribute to allergic and autoimmune inflammation. Developing projects include the contribution of IL-9 signaling to allergic inflammation and to the tumor microenvironment.

Professor Kaplan has been on the Editorial Boards of the Journal of Immunology and JAK-STAT and is currently the Editor-In-Chief for the new American Association of Immunologists journal ImmunoHorizons. He has served on and chaired numerous study sections for grant application to the National Institutes of Health, and other private and international review panels. He has served on the IUSM Biomedical Research Committee for over ten years and is currently the co-chair. He is also the Director of the NIH-funded T32 Training Program in Immunology and Infectious Diseases.