Research Program: Transplant Biology & Therapy
Assistant Professor, Department of Medicine

iizuk001@umn.edu
612-626-5620 — office
612-626-5569 — lab

Dr. Iizuka is an assistant professor in the Department of Medicine at the University of Minnesota. He received his M.D. in 1987 from Hirosaki University, Japan. After postdoctoral training at Washington University in St. Louis in the laboratory of Dr. Wayne Yokoyama, he joined the University of Minnesota in 2004.

Research Interests

My research focuses on natural killer (NK) cell biology, especially its molecular recognition and tolerance mechanisms.

NK cells kill tumors and virus-infected cells. NK cell killing and its tolerance mechanisms in normal and pathological settings have been explained by regulation of MHC class I molecules expressed by target cells, a phenomenon that led to the "Missing-Self" hypothesis. However, MHC class I-specificity does not account for all aspects of NK cell target recognition.

By expression cloning, we recently identified the ligand for the NK cell inhibitory receptor, Nkrp1d. The ligand is lectin-like and expressed constitutively in dendritic cells (DC) and macrophages. This finding has revealed a novel MHC class I-independent tolerance mechanism in NK cell recognition systems and indicated the cognate interaction between DC and NK cells through these molecules.

Employing molecular and cellular biology techniques, I explore the MHC class-I independent NK cell regulations, the area called "Beyond Missing-Self."

Selected Publications

Furukawa H, Iizuka K, Poursine-Laurent J, Shastri N, Yokoyama WM. A ligand for the murine NK activationg receptor Ly49D: Activation of tolerized NK cells from b2 microglobulin-deficient mice. Journal of Immunology. 169:126-136, 2002.

Iizuka K., Naidenko OV, Plougastel BF, Fremont DH, Yokoyama WM. Genetically linked C-type lectin-related ligands for Nkrp1 family of NK cell receptors. Nature Immunology. 4(8):801-807, 2003.

Iizuka K., Nakajima C, Iizuka Y-M, Takase M, Kato T, Noda S, a. Tanaka K, and Kanagawa. O. Protection from lethal infection by adoptive transfer of CD8 T cells genetically engineered to express virus-specific innate immune receptor. Journal of Immunology.179:1122-8, 2007.

Iizuka K., Scalzo, A.A., Xian, H. & Yokoyama, W.M. Regulation of the NK cell alloreactivity to bone marrow cells by the combination of the host NK gene complex and MHC haplotypes. J Immunol 180, 3260-3267 (2008).