Research Themes

• Pathogenesis of vasculitis and novel diagnostic and therapeutic strategies
  Grants-in-Aid for Scientific Research
  2008 - 2010
  ISHIZU Akihiro, TOMARU Utano, IWASAKI Sari
  Autoreactive vasculitogenic T cell clones were established from env-pX rats, which develop medium to small-sized vasculitis. Identification of the T cell target and the mechanism of vascular injury induced by the T cells might result in the development of novel therapeutic strategies for vasculitis. The transcriptome analysis was performed using the peripheral blood obtained from patients with microscopic polyangiitis (MPA) before and 1 week after the treatment. Sixteen genes were nominated as distinguished indicators that could predict prognosis of patients with MPA at an early point during the therapy.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 20590390
• Analysis of CD8 positive monocytes in human peripheral blood
  Grants-in-Aid for Scientific Research
  2008 - 2009
  IWASAKI Sari
  CD8 is mainly expressed on cytotoxic T lymphocytes. In this study, CD8+ monocytes in human peripheral blood were identified by whole blood erythrocyte lysis method in flow cytometry. CD8 molecules on monocytes were constituted by CD8α and CD8 β subunits; however, the mRNA expression of neither CD8α nor CD8β was detected in CD8+ monocytes. We therefore hypothesized that CD8 molecules were transferred to monocytes from cells other than monocytes. Initially, it was shown that serum was essential for the detection of CD8+ monocytes. Next, we revealed that CD8 molecules were derived from T cells, and that cell-to-cell contact between the monocytes and T cells was required for the transfer of CD8 molecules to monocytes. Furthermore, Fcγ receptor II (CD32) on monocytes and dynamism of cell membrane and cytoskeleton were involved in the mechanism of the CD8 translocation. Interestingly, CD3 and αβT cell receptor (TCR) were also transferred from T cells to monocytes accompanied by CD8. Collective evidences indicated that cell surface CD8, and also CD3 and αβTCR molecules on T cells, were transferred to monocytes via an intercellular exchange of plasma membrane, which is recently termed trogocytosis, under the presence of serum and the anti-CD8 monoclonal antibody.
  Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (B), Hokkaido University, 20790409