Comprehensive analysis of antibody responses to Plasmodium falciparum repetitive interspersed family (RIFIN) proteins

2019 Fiscal Year Research-status Report

• Project/Area Number: 19K16630
• Research Institution: Ehime University
• Principal Investigator: Nganga KanoiBernard 愛媛大学, プロテオサイエンスセンター, 特定研究員 (30824817)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: Malaria / Immunity / Falciparum

Outline of Annual Research Achievements

This study aimed at assessing the the specific proteins that are targets of naturally acquired immunity against Plasmodium falciparum clinical malaria in individuals residing in a malaria endemic region in Uganda. In the initial analysis, we observed that > 98% of assayed proteins (n=265) were immunogenic in malaria-exposed individuals in Uganda. The overall breadth of immune responses was significantly correlated with age but not with clinical malaria outcome among the study volunteers. Children with high levels of antibodies to four RIFINs a STEVOR, and SURFIN 1.2 displayed reduced the risk of developing clinical malaria. This antigens are potential targets of protective immunity and need further investigation. Manuscript based on this data < Global repertoire of human antibodies against Plasmodium falciparum RIFINs, SURFINs, and STEVORs in a malaria exposed population> has just been accepted for publication in Frontiers in Immunology journal.

Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

The work is progressing as planned.

Strategy for Future Research Activity

This study aims at contributing to malaria vaccine development studies aiming at developing vaccine based on the antigens that are targets of naturally acquired protective immunity.
therefore, in the next phase, analysis of specific Immunoglobulin G subclass will be considered to differentiate their role in protective immunity and identify other factors that are involved.
In addition, follow up studies targeting the selected RIFINs will be initiated to assess their mechanisms of action of the observed protective immunity.

Research Products

• [Journal Article] Global repertoire of human antibodies against Plasmodium falciparum RIFINs, SURFINs, and STEVORs in a malaria exposed population (2020)
  • Author(s): Kanoi Bernard N.、Nagaoka Hikaru、Morita Masayuki、White Michael T.、Palacpac Nirianne M.Q.、Ntege Edward H.、Balikagala Betty、Yeka Adoke、Egwang Thomas G.、Horii Toshihiro、Tsuboi Takafumi、Takashima Eizo
  • Journal Title: Frontiers in Immunology Volume: "" Pages: ""
  • DOI: doi: 10.3389/fimmu.2020.00893
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The N-Terminal Region of Plasmodium falciparum MSP10 Is a Target of Protective Antibodies in Malaria and Is Important for PfGAMA/PfMSP10 Interaction (2019)
  • Author(s): Nagaoka Hikaru、Kanoi Bernard N.、Jinoka Kana、Morita Masayuki、Arumugam Thangavelu U.、Palacpac Nirianne M. Q.、Egwang Thomas G.、Horii Toshihiro、Tsuboi Takafumi、Takashima Eizo
  • Journal Title: Frontiers in Immunology Volume: 10 Pages: ""
  • DOI: https://doi.org/10.3389/fimmu.2019.02669
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] Human antibody repertoires to RIFINs and STEVORs associate with reduced risk to febrile malaria (2019)
  • Author(s): Kanoi BN, Nagaoka N, Morita M, White MT, Palacpac NM, Ntege EH, Balikagala B, Yeka A, Egwang TG, Horii T, Tsuboi T, Takashima E.
  • Organizer: American Society of Tropical Medicine and Hygiene 68th Annual Meeting, 20th-24th, November 2019, National Harbor, Maryland, USA.
  • Int'l Joint Research