Lymphocyte stimulatory capacity of Theileria annulata-infected ovine lymphoblastoid cells

The interplay of cytokines in bovine tropical theileriosis: a mini review

Studying cytokine profiling in Theleria annulata infection enhances our understanding of how the immune response unfolds, the intricate interactions between the host and the parasite, the strategies employed by the parasite to evade the immune system, and potential avenues for developing treatments. The generation of pro-inflammatory cytokines plays a pivotal role in the immune response against T. annulata infection. Elevated concentrations of these cytokines potentially contribute to the manifestation of clinical symptoms associated with the disease, such as fever, anemia, exophthalmia, and weight loss. The production of anti-inflammatory cytokines potentially serves as a regulatory mechanism for the immune response, preventing the development of severe disease. Nevertheless, in animals afflicted by T. annulata infection, there is often a notable decrease in the levels of these cytokines, suggesting that they may not be as effective in mitigating the disease as they are in uninfected animals. This knowledge can be harnessed to develop improved diagnostic methods, treatments, and vaccines for tropical theileriosis. The objective of this current mini review is to achieve the same goal by consolidating the available knowledge of cytokine interactions in Bovine Tropical Theileriosis (BTT).

Identification of different Theileria species (Theileria lestoquardi, Theileria ovis, and Theileria annulata) in naturally infected sheep using nested PCR-RFLP

Ovine theileriosis is an important hemoprotozoal disease of sheep and goats in tropical and subtropical regions that leads to economic losses in these animals. A nested PCR-restriction fragment length polymorphism (RFLP) was carried out to identification Theileria species in sheep in some area in western half of Iran (Sari, Rasht, Urmia, Ilam, and Ahvaz). Two hundred and fifty blood samples were taken from sheep during tick activating season (summer of 2008). Microscopic examination revealed that 9.2% (23/250) sheep were infected by Theileria spp. piroplasms. Parasitemia ranged from 0.011% to 0.015%. In nested PCR assessment of DNA samples, 32.8% (82/250) sheep were positive. The negative samples were confirmed by amplifying of ovine beta-actin gene as an internal control. The differentiation of Theileria species was based on RFLP patterns using three restriction enzymes: HpaII, Rsa1, and Bsh 1285I. Out of 82 positive samples, 54.8% (45/82) and 40.2% (33/82) were positive for Theileria lestoquardi and Theileria ovis respectively. Mixed infection was detected in 4.8% (4/82) cases. Based on their PCR product digestion pattern with HpaII (1178, 900, 278, and 106 bp), it seemed to be mixture of Theileria annulata and T. lestoquardi. The presence of T. annulata was supported by sequence analysis. This is the first report of naturally infected sheep with T. annulata in Iran. Geographical distribution of Theileria species in sheep is shown according to the result of microscopy and nested PCR and RFLP data.

Molecular genetic characterization and subcellular localization of a putative Theileria annulata membrane protein

A Theileria annulata protein (TaD) exhibiting an N-terminal signal sequence for endoplasmic reticulum membrane translocation and a conserved cysteine-rich region was isolated by screening the mRNA of a T. annulata-infected bovine lymphoblastoid cell line with degenerated primers directed against T. annulata-targeting sequences. The TaD-coding sequence was found to be most closely related to the genomic DNA sequence of T. parva (TIGR database, 72%) and the amino acid sequence of Plasmodium falciparum (41%), P. yoelii yoelii (38%) and Cryptosporidium parvum (36%). The TaD mRNA is expressed within the sporozoite, schizont and merozoite stages of the parasite, implying that it is constitutively transcribed throughout the parasite's life cycle. Allelic variants were found between isolates originating from different geographical regions, however not affecting conserved cysteines. The open reading frame encoded a protein of 19.5 kDa and non-reducing SDS-PAGE analysis demonstrated a homodimeric protein. Using confocal microscopy, the protein was found to be both located in the parasite cytoplasm and to colocalize with a transmembrane protein of the schizonts within infected cells.