The mechanism of NKT cell-mediated persistent antibody production and host protection by a new pneumococcal vaccine

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H03705
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 54030:Infectious disease medicine-related
• Research Institution: Jikei University School of Medicine
• Principal Investigator: Kinjo Yuki 東京慈恵会医科大学, 医学部, 教授 (20570831)
• Co-Investigator(Kenkyū-buntansha): 林崎 浩史 東京慈恵会医科大学, 医学部, 助教 (50779907) ; 高橋 宜聖 国立感染症研究所, 治療薬・ワクチン開発研究センター, センター長 (60311403) ; 高塚 翔吾 国立感染症研究所, 真菌部, 研究員 (90609398)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 肺炎球菌感染症 / ワクチン / 抗体 / NKT / 糖脂質

Outline of Final Research Achievements

Pneumococcus is a major cause of pneumonia and meningitis. The incidence of pneumococcal disease is prominent in children and adults with the age of 65 or older. Therefore, pneumococcal vaccines are used for the children and elderly as routine vaccinations in Japan. The pneumococcal vaccine is effective for the serotypes that are included in the vaccine. Because there are about 100 serotypes in Pneumococcus, pneumococcal diseases caused by non-vaccine serotypes are increasing.

To develop a new pneumococcal vaccine that provides broad protection to various serotypes of Pneumococcus, we have studied the protective effect of a new pneumococcal vaccine against pneumococcal infection. We have obtained the data to show that the new vaccine provides the protection against pneumococcal infection by inducing antigen-specific antibodies. Through the immunological analysis, we have elucidated a new mechanism of NKT cell-mediated induction of antibody-producing cells.

Free Research Field

感染免疫学・細菌学・ワクチン学

Academic Significance and Societal Importance of the Research Achievements

肺炎は本邦での主な死因であり，髄膜炎は小児でも致死的または重篤な障害をもたらす。肺炎球菌はこれらの重症感染症をひきおこす主な原因菌である。そのため，有効性の高い新規ワクチンの開発は社会的に重要である。

私達は幅広い感染防御効果をもたらす肺炎球菌ワクチンの開発を目指し，新規肺炎球菌蛋白・糖脂質ワクチンによる抗体産生を介した感染防御効果を明らかにした。本ワクチンによる感染防御に重要な役割を担うリンパ球の濾胞性ヘルパーNKT細胞の誘導およびその細胞を介した抗体産生細胞の誘導機構の一端を明らかにした。本知見をもとに有効性に優れたワクチンの開発に繋がる可能性が期待され，学術的意義が高いと考えられる。