RMgmDB - Rodent Malaria genetically modified Parasites

Summary

RMgm-5147
Malaria parasiteP. berghei
Genotype
MutatedGene model (rodent): PBANKA_0403200; Gene model (P.falciparum): PF3D7_0304600; Gene product: circumsporozoite (CS) protein (CS; CSP)
Details mutation: P.berghei CSP replaced with P. falciparum CSP with ADGNPDP deleted and 3 of 4 NVDP changed to NANP
Transgene
Transgene not Plasmodium: A fusion of GFP (gfp-mu3) and Luciferase Firefly (LucIAV)
Promoter: Gene model: PBANKA_1133300; Gene model (P.falciparum): PF3D7_1357100; Gene product: elongation factor 1-alpha (eef1a)
3'UTR: Gene model: PBANKA_0719300; Gene product: bifunctional dihydrofolate reductase-thymidylate synthase, putative (dhfr/ts)
Replacement locus: Gene model: PBANKA_0306000; Gene product: 6-cysteine protein (230p)
Phenotype Liver stage;
Last modified: 17 January 2022, 17:50
  *RMgm-5147
Successful modificationThe parasite was generated by the genetic modification
The mutant contains the following genetic modification(s) Gene mutation, Introduction of a transgene
Reference (PubMed-PMID number) Reference 1 (PMID number) : 34748617
MR4 number
Parent parasite used to introduce the genetic modification
Rodent Malaria ParasiteP. berghei
Parent strain/lineP. berghei ANKA
Name parent line/clone P. berghei ANKA 676m1cl1 (RMgm-29)
Other information parent line676m1cl1 (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).
The mutant parasite was generated by
Name PI/ResearcherFlores-Garcia Y, Zavala F
Name Group/DepartmentJohns Hopkins Bloomberg School of Public Health, Department of Molecular Microbiology and Immunology
Name InstituteMalaria Research Institute
CityBaltimore, Maryland
CountryUSA
Name of the mutant parasite
RMgm numberRMgm-5147
Principal nameJR+MR (Junction + Minor Repeat KO)
Alternative name
Standardized name
Is the mutant parasite cloned after genetic modificationYes
Phenotype
Asexual blood stageNot different from wild type
Gametocyte/GameteNot different from wild type
Fertilization and ookineteNot different from wild type
OocystNot different from wild type
SporozoiteNot different from wild type
Liver stageAll 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


  Mutated: Mutant parasite with a mutated gene
Details of the target gene
Gene Model of Rodent Parasite PBANKA_0403200
Gene Model P. falciparum ortholog PF3D7_0304600
Gene productcircumsporozoite (CS) protein
Gene product: Alternative nameCS; CSP
Details of the genetic modification
Short description of the mutationP.berghei CSP replaced with P. falciparum CSP with ADGNPDP deleted and 3 of 4 NVDP changed to NANP
Inducable system usedNo
Short description of the conditional mutagenesisNot available
Additional remarks inducable system
Type of plasmid/construct(Linear) plasmid double cross-over
PlasmoGEM (Sanger) construct/vector usedNo
Modified PlasmoGEM construct/vector usedNo
Plasmid/construct map
Plasmid/construct sequence
Restriction sites to linearize plasmid
Selectable marker used to select the mutant parasitehdhfr
Promoter of the selectable markerunknown
Selection (positive) procedurepyrimethamine
Selection (negative) procedureNo
Additional remarks genetic modificationPyrimethamine plasmids (pR-CSPFL) encoding the different versions of PfCSP or PbCSP, along with the PbCSP signal sequence, were obtained from Bio Basic Inc. Plasmid transfections were performed as previously described to generate the different transgenic parasites lines. All plasmids include the hDHFR selection cassette and csp 5’ and 3’ UTRs. pR-CSPFL was excised with XhoI and KasI
Additional remarks selection procedure
Primer information: Primers used for amplification of the target sequences  Click to view information
Primer information: Primers used for amplification of the target sequences  Click to hide information
Sequence Primer 1
Additional information primer 1
Sequence Primer 2
Additional information primer 2
Sequence Primer 3
Additional information primer 3
Sequence Primer 4
Additional information primer 4
Sequence Primer 5
Additional information primer 5
Sequence Primer 6
Additional information primer 6

  Transgene: Mutant parasite expressing a transgene
Type and details of transgene
Is the transgene Plasmodium derived Transgene: not Plasmodium
Transgene nameA fusion of GFP (gfp-mu3) and Luciferase Firefly (LucIAV)
Details of the genetic modification
Inducable system usedNo
Additional remarks inducable system
Type of plasmid/construct(Linear) plasmid double cross-over
PlasmoGEM (Sanger) construct/vector usedNo
Modified PlasmoGEM construct/vector usedNo
Plasmid/construct map
Plasmid/construct sequence
Restriction sites to linearize plasmid
Selectable marker used to select the mutant parasitegfp (FACS)
Promoter of the selectable markereef1a
Selection (positive) procedureFACS (flowsorting)
Selection (negative) procedureNo
Additional remarks genetic modification
Additional remarks selection procedure
Other details transgene
Promoter
Gene Model of Parasite PBANKA_1133300
Gene Model P. falciparum ortholog PF3D7_1357100
Gene productelongation factor 1-alpha
Gene product: Alternative nameeef1a
Primer information details of the primers used for amplification of the promoter sequence  Click to view information
Primer information details of the primers used for amplification of the promoter sequence  Click to hide information
Sequence Primer 1
Additional information primer 1
Sequence Primer 2
Additional information primer 2
3'-UTR
Gene Model of Parasite PBANKA_0719300
Gene productbifunctional dihydrofolate reductase-thymidylate synthase, putative
Gene product: Alternative namedhfr/ts
Primer information details of the primers used for amplification the 3'-UTR sequences  Click to view information
Primer information details of the primers used for amplification the 3'-UTR sequences  Click to hide information
Sequence Primer 1
Additional information primer 1
Sequence Primer 2
Additional information primer 2
Insertion/Replacement locus
Replacement / InsertionReplacement locus
Gene Model of Parasite PBANKA_0306000
Gene product6-cysteine protein
Gene product: Alternative name230p
Primer information details of the primers used for amplification of the target sequences  Click to view information
Primer information details of the primers used for amplification of the target sequences  Click to hide information
Sequence Primer 1
Additional information primer 1
Sequence Primer 2
Additional information primer 2
Sequence Primer 3
Additional information primer 3
Sequence Primer 4
Additional information primer 4