Mutant/mutation
The mutant expresses a fusion protein of OVA (ovalbumin) and mCherry under the constitutive hsp70 promoter.The mutant does not contain a drug-selectable marker.

The mutant has been generated and selected using the GIMO transfection method ('gene insertion/marker out') of transfection of a GIMO mother line that contains the hdhfr::yfcu selectable marker into the silent 230p locus.

The mutant has been generated in the reference line GIMO_PbNK65 (RMgm-1115). This GIMO mother line is used for introduction of transgenes into the modified 230p locus through transfection with constructs that target the 230p locus. These constructs insert into the 230p locus (‘gene insertion’), thereby removing the hdhfr::yfcu selectable marker (‘marker out’) from the genome of the mother lines. Transgenic parasites that are marker-free are subsequently selected by applying negative drug selection using 5-FC. This selection procedure is performed in vivo in mice

Protein (function)

Phenotype
High expression of OVA::mCherry in blood stages.
These transgenic parasites were used to examine the effect of antigen subcellular-location and expression-level on the development of T-cell responses during blood-stage infections. Blood-stage parasite induced activation and proliferation of OVA-specific CD8+ T-cells (OT-I) and CD4+ T-cells (OT-II).

Evidence is presented that the location of OVA in parasites (cytosolic or at the parasitophorous vacuole membrane, PVM) influences the strength of T-cell responses. Parasites expressing OVA fused to the PVM protein HEP17 (RMgm-1116) induce stronger OVA-specific T-cell responses than parasites expressing cytosolic OVA-fused to mCherry. Parasites expressing unconjugated OVA showed low levels of OVA expression, indicating that unconjugated OVA is unstable. ....

Additional information

Other mutants
P. berghei ANKA parasites expressing OVA fused to the PVM protein HEP17 (RMgm-1116).
RMgm-1117 and RMgm-1118: OVA expressing parasites made in P. berghei NK65. These are comparable to the P. berghei ANKA OVA expressing parasites RMgm-1112 and RMgm-1116

Click on Ovalbumin for more rodent malaria mutants expressing OVA