Koho Iizuka, M.D. Assistant Professor Department of Medicine Hirosaki University School of Medicine, 1987, M.D. iizuk001@umn.edu 612-626-5620 office 612-626-5569 lab

Research Interests:

Natural Killer Cell Biology

Projects In My Laboratory:
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 as “Beyond Missing-Self”.

Selected Recent Publications:

• Furukawa, H., K. Iizuka, J. Poursine-Laurent, N. Shastri, W. M. Yokoyama. 2002. 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.

• Iizuka, K., O. V. Naidenko, B. F. M. Plougastel, D. H. Fremont, W. M. Yokoyama. 2002. Genetically linked C-type lectin-related ligands for Nkrp1 family of NK cell receptors. Nature Immunology. 4(8):801-807.

Last modified: April 26, 2004