Jae-Hwan Nam is currently a Professor of the Department of Biotechnology at the Catholic University of Korea. He has received his PhD from the Department of Biology at Korea University and has worked as a Senior Research Scientist at the KNIH and as Postdoctoral Researcher at the NIAID, NIH. He has researched about vaccine, viral vector systems; virus induced signal pathways and more recently about virus induced obesity. He has published more than 100 scientific articles and has been serving as an Editorial Board Member of International Journal of Obesity, Journal of Bacteriology and Virology and Clinical and Experimental Vaccine Research.
It is known that vaccination is required to induce the production of antigen specific effector and memory immune cells. This process involves various growth hormones and cytokines. Among them, insulin-like growth factor-1 (IGF-1), derived from macrophages, plays important roles in immune functions as well as in cellular metabolism. Based on previous studies, we investigated the correlation between macrophage induced IGF-1 and the production of vaccine mediated effector/memory immune cells using macrophage derived IGF-1 gene knockout (MIKO) mice. Wild-type (WT) control and MIKO mice were immunized twice with influenza virus vaccine at an interval of 3 weeks. The titers of influenza specific antibody induced by the vaccine were checked 2 weeks after the first vaccination. The titers were significantly lower in vaccinated MIKO mice than in vaccinated WT mice from 1 week after the second immunization, which means that the MIKO mice did not show any boost in the effect of the vaccine. Moreover, the populations of CD138+B220+ antibody secreting B-cells were lower in MIKO mice than in WT mice with or without vaccine treatment. Therefore, the low antibody titers might be caused by a reduction in the production of antibody secreting B-cells in MIKO mice. Taken together, although we could not identify the mechanism, these results suggest that macrophage derived IGF-1 might play a role in the functions of vaccine activated effector B cells.
Hyewon Youn has completed her PhD from Texas Tech University and Postdoctoral studies from Southwest Cancer Center in TX, USA. She serves as a Professor in Seoul National University and a Board Member of Korean Society of Nuclear Medicine. She has published more than 70 papers in reputed journals and has been serving as an Editorial Board Member of Nuclear Medicine and Molecular Imaging.
By taking advantage of bioluminescence imaging to monitor luciferase expressing splenocytes from the luciferase transgenic mouse, we visualized the enhancement of immune response against hepatitis B virus (HBV) vaccine with adjuvants. To visualize antigen in vivo, large hepatitis B virus antigen (L-HBsAg) was labeled with radioiodine (125I). B6 mice were intramuscularly vaccinated. The localization of 125I-L-HBsAg was monitored for 5 weeks using animal SPECT/CT. To monitor the immune response, the luciferase expressing splenocytes were injected intravenously into immunized B6 mice. Bioluminescence signals from splenocytes were measured by IVIS 100 system. Localization of inoculated L-HBsAg was successfully monitored using animal SPECT/CT. L-HBsAg was lasted for 5 weeks and diminished. In addition, the injected splenocytes were successfully visualized in immunized mice, homing to spleen within 30 minutes and were accumulated in lymph nodes within 5 hours. Accumulation of splenocytes at vaccination site was observed within 24 hours. Moreover, after 10 hours, mouse vaccinated with antigen and two adjuvants showed 4 times more accumulation of splenocytes at vaccination site compared to mouse vaccinated with antigen only. Six days later, mouse vaccinated with antigen and two adjuvants showed 1.7-4.73 fold increased luciferase intensity of splenocytes at spleen, lymph nodes and vaccination site compared to mouse vaccinated with antigen only. In conclusion, in vivo real-time bioluminescent monitoring of splenocytes homing and proliferation against vaccination successfully provides efficiency of adjuvants. Our imaging system can be used for evaluation of efficacy of vaccination by enhanced the proliferation and activation of splenocytes near the vaccination site.