Biomedical subjects

Hisato Takagi

Publications and source records attributed to Hisato Takagi.

74 records · Page 5Linked to original sources

PubMedDate not supplied

Helper T-cell type 1 or type 2 function of xeno-MHC-restricted T-cell clones in a direct xenoantigen recognition.

There have been several reports that xeno-MHC-restricted T-cells have a cytotoxic function through a direct xenoantigen recognition, but yet no report that they have a helper function. Previously we showed that both xeno-MHC-restricted CD4(+) and CD8(+) T-cells recognized xenoantigens directly in a mouse anti-rat combination. In this study, we investigated whether or not xeno-MHC-restricted T-cells had a helper function. Mouse T-cell clones recognizing rat antigens directly were derived from T-cell lines using the limiting dilution method. Phenotype, cytotoxic activity and cytokine production of these clones were analyzed by flow cytometry, 51Cr release assay and ELISA, respectively. Rat-MHC class I-restricted mouse CD8(+) T-cell clones showed a specific cytotoxic activity against rat antigens. One CD4(+) clone produced IL-4 and IL-10, and the other CD4(+) clone produced not T-helper (Th) 2 cytokine but TNF-alpha. Our results suggested that xeno-MHC class I-restricted CD8(+) T-cells should have a cytotoxic function, and xeno-MHC class II-restricted CD4(+) T-cells should have either Th1 or Th2 function.

Animals↗

PubMedDate not supplied

Nonviral gene gun mediated transfer into the beating heart.

Several techniques for gene transfer into the heart have been developed, including direct injection of naked plasmid DNA into the myocardium and coronary infusion of various viral vectors. However, complications and side effects with those methods have been reported. In this study, to resolve these problems, the authors investigated the feasibility of nonviral gene transfer into the beating heart with the hand held gene gun. The genes pCAGGS/CTLA4-EGFP were coated around the surface of gold particles. Three sizes of gold particles (0.6, 1.0, and 1.6 microm in diameter) and three settings of helium gas pressure (200, 250, and 300 psi) were examined. Gene transfer into the rat beating heart was performed using the hand held gene gun. EGFP expressions were detected by fluorescence microscopy from day 1 to 3 weeks after bombardment. The most prominent expressions were detected with the combination of 1.0 microm gold particles and 300 psi helium gas pressure. In this study, the present authors showed that non-viral gene transfer into the beating heart was feasible with the hand held gene gun. This technique is effective for gene transfer into the heart and may be one of the most useful methods for gene therapy for many cardiovascular diseases in the future.

Animals↗