bims-toxgon 2023-08-06 papers

Issue of 2023–08–06
three papers selected by
Lakesh Kumar, BITS Pilani

Trends Parasitol. 2023 Aug 02. pii: S1471-4922(23)00168-X. [Epub ahead of print]

Meiosis in Plasmodium: how does it work?

David S Guttery, Mohammad Zeeshan, Anthony A Holder, Eelco C Tromer, Rita Tewari.

Meiosis is sexual cell division, a process in eukaryotes whereby haploid gametes are produced. Compared to canonical model eukaryotes, meiosis in apicomplexan parasites appears to diverge from the process with respect to the molecular mechanisms involved; the biology of Plasmodium meiosis, and its regulation by means of post-translational modification, are largely unexplored. Here, we discuss the impact of technological advances in cell biology, evolutionary bioinformatics, and genome-wide functional studies on our understanding of meiosis in the Apicomplexa. These parasites, including Plasmodium falciparum, Toxoplasma gondii, and Eimeria spp., have significant socioeconomic impact on human and animal health. Understanding this key stage during the parasite's life cycle may well reveal attractive targets for therapeutic intervention.

Keywords: Plasmodium; diploid; haploid; meiosis; reversible protein phosphorylation; zygote

DOI: https://doi.org/10.1016/j.pt.2023.07.002

J Parasit Dis. 2023 Sep;47(3): 608-618

The effects of intracellular iron availability on the outcome of Toxoplasma gondii infection in mice.

Eman Mostafa, Faten Al-Sayed Mohammed Sayed Ahmed, Samah Hassan Yahia, Alia Ibrahim Mohamed Ibrahim, Enas Saed Elbahaie.

Toxoplasma gondii (T. gondii) is a parasite that obtains the iron it needs for its own metabolism from the host-cell iron pool. In this work, we aimed to investigate if iron supplementation or deficiency affected the course of T. gondii infection. Eighty mice were divided into four groups, each with 20 animals: Group (I): Uninfected control group. Group (II): Infected control group: injected with Phosphate buffered saline. Group (III): Infected group: received iron sucrose treatment. Group (IV): Infected group: treated with deferoxamine. Quantitative PCR studies were performed on days 3 and 8 post-infection to detect the expression of iron metabolism genes (hamp and ferroprotin) and immune-histochemical analysis to study the percentage of TNF-α and TGF-β tissue expression. Iron supplementation induced progressions of infection evident by increased tissue expression of pro-inflammatory cytokine TNF-α and downregulation of TGF-β which is mostly linked to suppression of the inflammatory process caused by T. gondii. Increased expression of TGF-β and decreased expression of TNF-α was noticed when iron deprivation occurred. On day 3, we noticed increased expression in the hamp gene with iron supplementation while it decreases when the iron supply is low. On the contrary, iron deficiency increased ferroprotin gene expression whereas supplementing decreased it. On day 8, the level of expression of these genes returned to normal levels. These observations document the potential role of iron in controlling toxoplasmosis infection and indicate that the transcription of hamp and ferroprotin in T. gondii-infected cells appears to be regulated by a sophisticated indirect mechanism.

Keywords: Immunohistochemistry; T. gondii; TGF-β; TNF-α; q-PCR

DOI: https://doi.org/10.1007/s12639-023-01603-9

Heliyon. 2023 Jul;9(7): e18176

Bioinformatics-based prediction and screening of immunogenic epitopes of Toxoplasma gondii rhoptry proteins 7, 21 and 22 as candidate vaccine target.

Fariha Ayub, Haroon Ahmed, Tehreem Sohail, Khuram Shahzad, Figen Celik, Xu Wang, Sami Simsek, Jianping Cao.

Introduction: Toxoplasmosis is a well-known zoonotic disease caused by Toxoplasma gondii. The main causes of the disease range from eating undercooked or contaminated meat and shellfish to cleaning litter trays into which cats that excreted toxoplasma via faeces. This pathogen can live for a very long time, possibly a lifetime, within the bodies of humans and other animals.
Aims and objectives: This study aimed to predict and analyse candidate immunogenic epitopes for vaccine development by evaluating the physio-chemical properties, multiple sequence alignment, secondary and tertiary structures, phosphorylation sites, transmembrane domains, and signal peptides, of T. gondii rhoptry proteins ROP7, ROP21, and ROP22 using bioinformatics tools.
Methods: To find immunogenic epitopes of rhoptry proteins, numerous bioinformatics web servers were used containing multiple sequence alignment, physiochemical properties, antigenicity and allergenicity, post-translational modification sites (PTMs), signal peptides, transmembrane domains, secondary and tertiary structures, and screening of predicted epitopes. We evaluated immunogenic linear B-cell epitopes as candidate proteins for vaccine development.
Results: Nine epitopes were identified for each protein, and analysis of immunogenicity, revealed three candidate epitopes for ROP7, one for ROP21, and four for ROP22. Among all candidate epitopes, ROP22 contained the most immunogenic epitopes with immunogenicity score of 0.50575.
Conclusion: We acquired detailed information on predicted immunogenic epitopes using in-silico methods. The results provide a foundation for further experimental analysis of toxoplasmosis, and potential vaccine development.

Keywords: Bioinformatics; Epitope; ROP21; ROP22; ROP7; Rhoptry proteins; Toxoplasma gondii; Vaccine

DOI: https://doi.org/10.1016/j.heliyon.2023.e18176