- Title Information
- Title
- IDENTIFICATION AND FUNCTIONAL CHARACTERIZATION OF P113 AS A NOVEL BLOOD-STAGE VACCINE TARGET AGAINST SEVERE PLASMODIUM FALCIPARUM MALARIA
- Type of Resource (primo)
- dissertations
- Name:
Personal
- Name Part
- Zheng, Yiyu
- Role
- Role Term:
Text
- creator
- Name:
Personal
- Name Part
- Kurtis, Jonathan D.
- Role
- Role Term:
Text
- Advisor
- Name:
Personal
- Name Part
- Wu, Hannah Wei
- Role
- Role Term:
Text
- Reader
- Name:
Personal
- Name Part
- Najrana, Tanbir
- Role
- Role Term:
Text
- Reader
- Name:
Corporate
- Name Part
- Brown University. Biology and Medicine: Biotechnology
- Role
- Role Term:
Text
- sponsor
- Origin Information
- Copyright Date
- 2026
- Physical Description
- Extent
- vii, 50 p.
- digitalOrigin
- born digital
- Note:
thesis
- Thesis (Sc. M.)--Brown University, 2026
- Genre (aat)
- theses
- Abstract
- Malaria is a leading cause of child mortality worldwide and a significant burden on global health. The severe malaria (SM) subtype is particularly consequential, carrying a case fatality rate of 20%. Although pre-erythrocytic vaccines such as RTS,S/AS01 and R21/Matrix-M have been approved for malaria prevention, they are limited in targeting SM cases, as their efficacy diminishes over time due to parasite resistance, and neither targets blood-stage parasites directly, which are especially responsible for SM pathology. Previous studies have shown that naturally acquired immunity to SM develops rapidly, usually after only one or two episodes. Since this immunity is mediated primarily by antibodies, this study aimed to identify the specific parasite antigens targeted by these protective responses.
In this thesis, we performed whole-proteome differential screening (WPDS) using post-SM plasma from our Kenyan cohort and a Plasmodium falciparum 3D7 cDNA library displayed in T7 phage, leading to the identification of 46 parasite proteins uniquely recognized by antibodies from children with severe malaria. Among these candidates, we prioritized PfP113 (P113; PF3D7_1420700) based on its enrichment, biochemical features, and biological relevance. P113 is a 112.6-kDa GPI-anchored merozoite surface protein which anchors the PfRh5 invasion complex to the merozoite surface and displays limited sequence variation across field isolates, making it an attractive vaccine candidate. PfGARP is a previously validated vaccine target from the Kurtis Laboratory, was independently recovered in the screen (34.4% of fourth-round clones) and was utilized as an internal positive control.
Recombinant P113 was expressed in Expi293F cells, purified by nickel-column immobilized metal affinity chromatography, and validated by LC-MS/MS mass spectrometry. Mice (BALB/c) immunized with recombinant P113 formulated with TiterMax Gold adjuvant developed anti-P113 antibodies. However, only ~20% of immunized mice (out of 45 mice, with initial cohort of 5 showing 1 responder) produced sera with growth-inhibitory activity against P. falciparum 3D7 parasites in vitro, as measured by growth inhibition assay.
Comparison of inhibitory and non-inhibitory sera indicated that both groups had comparable antibody titers and both recognized native P113 in parasite lysates by Western blot. This demonstrates that the growth-inhibitory phenotype is not determined by antibody quantity or overall antigen recognition. Epitope mapping revealed that inhibitory and non-inhibitory sera shared broadly similar binding profiles, yet the inhibitory sera uniquely recognized a shifted epitope, HLQGSEQSIEASESS, which suggests that antibodies targeting this specific region may be responsible for functional parasite growth inhibition.
Collectively, these findings advance P113 from a bioinformatically identified candidate to a functionally validated blood-stage vaccine antigen. This study also provides the first evidence that immunization-induced anti-P113 antibodies can inhibit P. falciparum growth. The identification of a candidate inhibitory epitope establishes a foundation for focused peptide–conjugate immunization strategies aimed at improving the responder rate. This work contributes to the expanding repertoire of blood-stage antigens targeting severe P. falciparum malaria and supports the development of P113 as a component of a multi-antigen vaccine strategy.
- Subject (fast)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/01019337")
- Topic
- Mice
- Subject (fast)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/01163573")
- Topic
- Vaccines
- Subject (fast)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/01006371")
- Topic
- Malaria vaccine
- Subject (fast)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/01154588")
- Topic
- Transfection
- Subject (fast)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/01066401")
- Topic
- Plasmodium falciparum
- Subject
- Topic
- severe malaria
- Subject
- Topic
- Antibody
- Subject
- Topic
- P113 Protein
- Subject
- Topic
- whole proteome differential screening (WPDS)
- Subject
- Topic
- Vaccine antigen discovery
- Subject
- Topic
- Epitope mapping
- Subject
- Topic
- Growth inhibition assay
- Subject (fast)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/02021255")
- Topic
- Merozoite surface proteins
- Subject
- Topic
- Protective immunity
- Language
- Language Term (ISO639-2B)
- English
- Record Information
- Record Content Source (marcorg)
- RPB
- Record Creation Date
(encoding="iso8601")
- 20260516