| Successful modification | The parasite was generated by the genetic modification |
| The mutant contains the following genetic modification(s) |
Gene mutation
|
| Reference (PubMed-PMID number) |
Reference 1 (PMID number) : 33709544
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| 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 cl15cy1
|
| Other information parent line | A reference wild type clone from the ANKA strain of P. berghei (PubMed: PMID: 17406255). |
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| The mutant parasite was generated by |
| Name PI/Researcher | Müller K, Hafalla JCR |
| Name Group/Department | Department of Infection Biology, Faculty of Infectious and Tropical Diseases |
| Name Institute | London School of Hygiene and Tropical Medicine |
| City | London |
| Country | UK |
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| Name of the mutant parasite |
| RMgm number | RMgm-4991 |
| Principal name | UIS4(SIINFEKL) |
| 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 | Not different from wild type |
| Additional remarks phenotype | Mutant/mutation
In the mutant the uis4 gene has been replaced with a mutated uis4 gene encoding UIS4 that is C-terminally tagged with the amino acids SIINFEKL (SIINFEKL is a H-2-Kb-restricted CD8+ T-cell epitope of ovalbumin).
The addition of SIINFEKL allowed for recognition in H-2-Kb-carrying C57Bl6 mice.
Protein (function)
UIS4 has been identified by transcription-profiling of sporozoites (Kaiser et al., (2001). Mol. Microbiol. 51, 1221-32). The protein is expressed throughout liver stage development and localizes to the parasitophorous vacuole.
Phenotype
The resulting parasites showed a phenotype comparable to WT parasites, with comparable mosquito infectivity and number of salivary gland sporozoites, functional sporozoite motility and normal invasive capacity and development inside hepatocytes. Thus, the introduced mutations to generate UIS4SIINFEKL parasites did not interfere with the completion of the life cycle, in either mosquito vector or mouse. All C57BL/6 mice that received 800 sporozoites of UIS4SIINFKEL intravenously developed a detectable (patent) blood stage infection by day 4, comparable to infection with WT sporozoites
Additional information
From the Abstract:
'We engineered Plasmodium berghei parasites that harbour a well-characterised epitope for stimulation of CD8+ T cells, either as an antigen in the sporozoite surface-expressed circumsporozoite protein or the parasitophorous vacuole membrane associated protein upregulated in sporozoites 4 (UIS4) expressed in exo-erythrocytic forms (EEFs). We show that the antigen origin results in profound differences in immunogenicity with a sporozoite antigen eliciting robust, superior antigen-specific CD8+ T-cell responses, whilst an EEF antigen evokes poor responses. Despite their contrasting immunogenic properties, both sporozoite and EEF antigens gain access to antigen presentation pathways in hepatocytes, as recognition and targeting by vaccine-induced effector CD8+T-cells results in high levels of protection when targeting either antigen. Our study is the first demonstration that poorly immunogenic EEF antigens do not preclude their susceptibility to antigen-specific CD8+ T-cell killing.'
Other mutants |
*RMgm-4991
