Investigating the Leishmania donovani sacp Gene and Its Role in Macrophage Infection and Survival in Mice

Abstract

The protozoan parasite Leishmania donovani is a causative agent of the neglected tropical disease known as visceral leishmaniasis, which can be lethal when untreated. Studying Leishmania viru-lence factors is crucial in determining how the parasite causes disease and identifying new targets for treatment. One potential virulence factor is L. donovani’s abundantly secreted protein: secreted acid phosphatase (SAcP). Whole-genome analysis revealed that the sacp gene was present in three copies in wild type L. donovani. Using CRISPR-Cas9 gene editing; we generated a sacp gene knockout termed LdΔSAcP, which demonstrated a loss of both the SAcP protein and an associated reduction in secreted acid phosphatase activity. Genome sequencing confirmed the precise dele-tion of the sacp gene in LdΔSAcP and identified several changes in the genome. LdΔSAcP demonstrated no significant changes in promastigote proliferation or its ability to infect and survive in macrophages compared to the wildtype strain. LdΔSAcP also demonstrated no change in murine liver infection; however, survival was impaired in the spleen. Taken together these results show that SAcP is not necessary for the survival of promastigotes in culture but may support long-term survival in the spleen. These observations also show that the use of CRISPR gene editing and WGS together are effective to investigate the function and phenotype of complex potential drug targets such as multicopy genes.

Advancement in Leishmaniasis Diagnosis and Therapeutics

“…Interestingly, the authors discussed the similarities in pathogenesis and the common strategies that might be used to treat these two apparently different diseases, and described the entire innovative process of the synthesis and construction of these compounds. Also, Paulini et al (2022) obtained via a gene editing technique using CRISPR-Cas9 Leishmania donovani knockout strains for the secreted acid phosphatase protein (SAcP) [ 14 ]. Among the data presented by the authors, this virulence factor proved to be very important in maintaining the parasites in the spleen of BALB/c mice.…”

“…Furthermore, it is described as an organ of parasitic persistence in visceral leishmaniasis [ 15 ]. Consequently, the study of Paulini et al pointed out that SAcP may be a promising target for the treatment of the disease [ 14 ].…”