Successful modification | The parasite was generated by the genetic modification |
The mutant contains the following genetic modification(s) |
Gene mutation,
Introduction of a transgene
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Reference (PubMed-PMID number) |
Reference 1 (PMID number) : 34748617 |
MR4 number |
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Parent parasite used to introduce the genetic modification |
Rodent Malaria Parasite | P. berghei |
Parent strain/line | P. berghei ANKA |
Name parent line/clone |
P. berghei ANKA 676m1cl1 (RMgm-29)
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Other information parent line | 676m1cl1 (RMgm-29) is a reference ANKA mutant line which expresses GFP-luciferase under control of a constitutive promoter. This reference line does not contain a drug-selectable marker (PubMed: PMID: 16242190). |
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The mutant parasite was generated by |
Name PI/Researcher | Flores-Garcia Y, Zavala F |
Name Group/Department | Johns Hopkins Bloomberg School of Public Health, Department of Molecular Microbiology and Immunology |
Name Institute | Malaria Research Institute |
City | Baltimore, Maryland |
Country | USA |
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Name of the mutant parasite |
RMgm number | RMgm-5145 |
Principal name | JR (Junction KO) |
Alternative name | |
Standardized name | |
Is the mutant parasite cloned after genetic modification | Yes |
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Phenotype |
Asexual blood stage | Not different from wild type |
Gametocyte/Gamete | Not different from wild type |
Fertilization and ookinete | Not different from wild type |
Oocyst | Not different from wild type |
Sporozoite | Not different from wild type |
Liver stage | All 5 mutants produced normal/wildtype numbers of oocysts and sporozoites and sporozoites showed normal/wildtype infectivity as measured by parasite liver loads after intravenous injection of purified sporozoites. |
Additional remarks phenotype | Mutant/mutation
In this study 5 mutants were generated that express mutated forms of P. berghei CSP
1) Pb expressing PfCSP with ADGNPDP deleted (JR KO)
2) Pb expressing PfCSP where the 4 NVDP were changed to NANP (MR KO)
3) Pb expressing PfCSP with ADGNPDP deleted and 3 of the 4 NVDP changed to NANP (JR+MR KO)
4) Pb expressing PbCSP containing the PfCSP JR sequence ADGNPDPNANPNVDP (JR KI)
5) Pb expressing PbCSP containing the PfCSP JR and MR sequences ADGNPDPNANPNVDPNANPNVDP (JR+MR KI)
To generate the transgenic Pb KO lines, the endogenous PbCSP was replaced with modified PfCSP versions lacking the JR (Junction KO), MR (Minor Repeat KO), or JR+MR (Junction + Minor Repeat KO). For transgenic Pb KI lines, the endogenous PbCSP (PbCSP WT) was replaced with modified versions of PbCSP containing short inserts corresponding to the JR (Junction KI) and JR+MR (Junction + Minor Repeat KI).
Protein (function)
The CS protein is the major protein on the surface of sporozoites and is critical for development of sporozoites within the oocysts and is involved in motility and invasion of both the salivary gland of the mosquito and the liver cells. The protein is also found on the oocyst plasma membrane and on the inner surface of the oocyst capsule. Specific motifs in CS are involved in sporozoite binding to mosquito salivary glands and in sporozoite attachment to heparan sulfate proteoglycans in the liver of the mammalian host. During substrate-dependent locomotion of sporozoites, CS is secreted at the sporozoite anterior pole, translocated along the sporozoite axis and released on the substrate at the sporozoite posterior pole. Following sporozoite invasion of hepatocytes, the CS is released in the host cell cytoplasm.
Phenotype
All 5 mutants produced normal/wildtype numbers of oocysts and sporozoites and sporozoites showed normal/wildtype infectivity as measured by parasite liver loads after intravenous injection of purified sporozoites
Additional information
From the Abstract:
'Here, we assessed whether junction-, minor repeat- and central repeat-preferring human mAbs (CIS43, L9 and 317 respectively) bound and protected against in vivo challenge with transgenic P. berghei (Pb) SPZ expressing either PfCSP with the junction and minor repeats knocked out (KO), or PbCSP with the junction and minor repeats knocked in (KI). In vivo protection studies showed that the junction and minor repeats are necessary and sufficient for CIS43 and L9 to neutralize KO and KI SPZ, respectively. In contrast, 317 required major repeats for in vivo protection. These data establish that human mAbs can prevent malaria infection by targeting three different protective epitopes (NPDP, NVDP, NANP) in the PfCSP repeat region.'
Other mutants |