Expression of a Major Piroplasm Surface Protein of Theileria sergenti in Sporozoite Stage.

Abstract

ABSTRACT. A 32 kilodalton major piroplasm surface protein (MPSP) is expressed abundantly on the surface of intraerythrocytic piroplasms of Theileria sergenti and is considered to be a candidate antigen for vaccine development against piroplasmosis. In this study, transcripts of MPSP gene were detected in an expression cDNA library prepared from T. sergenti-infected tick salivary glands. Expression of MPSP in the sporozoite stage was also confirmed by immunoblot analysis. Its expression at the sporozoite and intraerythrocytic stages gives scope for possible induction of protective immunity being targeted at both stages by immunization with recombinant MPSP.-KEY WORDS: major piroplasm surface protein expression, sporozoite, Theileria sergenti.J. Vet. Med. Sci. 61(3): 275-277, 1999 surface as demonstrated by immunoelectron microscopy [17]. The MPSP homologues ranging from 30 to 34 kDa are conserved among Theileria species [16], which suggested its biological significance in parasite growth. This molecule is also a candidate antigen for vaccine development because passive immunization with a monoclonal antibody to this molecule produced partial protection against parasite challenge with reduced clinical symptoms [19]. MPSPbased synthetic peptide vaccine was effective in reducing the level of parasitemia and severe anaemia [13]. The effectiveness of an MPSP-based vaccine was also demonstrated in T. annulata [1]. A recombinant vaccine against sporozoite stage was effective against East Coast fever caused by T. parva [10]. The analysis of antigens expressed in the sporozoite stage of T. sergenti should be carried out. The aim of this study was to determine whether MPSP is expressed in sporozoite stage, the infective form for mammalian hosts.T. sergenti Shintoku stock had been maintained in our laboratory by blood or tick passages in splenectomized calves. For the preparation of infected tick salivary glands and sporozoite materials, larvae of H. mageshimaensis provided by Dr. K. Takahashi, School of Veterinary Medicine, Rakuno Gakuen University, Japan, were fed on cattle showing parasitemia of approximately 10% and engorged larval ticks were kept in an incubator at 24˚C until moulting was complete. Four months later, the nymphal ticks were fed on rabbits at room temperature for 3 days to induce the maturation of parasites to sporozoites within the salivary glands. The infected salivary glands were dissected out of the ticks, washed with cold phosphatebuffered saline (PBS), solubilized in sample buffer for sodium dodecyl sulfate-polyacrylamide gel electrophoresis [8], and analyzed by immunoblot analysis. Figure 1 shows the result of immunoblot analysis using anti-MPSP monoclonal antibody (mAb), C9 [22]. This mAb recognized a protein with the a molecular mass of 32 kDa in sporozoite infected-salivary glands (Fig. 1 A, lane 1). This was exactly the same size as MPSP expressed in

Factors associated with seroconversion to the major piroplasm surface protein of the bovine haemoparasite Theileria orientalis

“…Many recent studies have focussed on identification and differentiation of various genotypes of T. orientalis . These genotypes are defined based on sequence variations in the gene encoding the major piroplasm surface protein (MPSP), an immunodominant antigen expressed during both sporozoite and piroplasm phases of the T. orientalis life-cycle [ 4 ]. While eleven genotypes of T. orientalis have been identified globally (Types 1-8 and N1-N3) [ 5 ], disease outbreaks in cattle have been largely limited to Type 2 (Ikeda genotype) [ 6 – 9 ], with only occasional reports of clinical cases linked to other genotypes [ 10 , 11 ].…”

Temporal dynamics and subpopulation analysis of Theileria orientalis genotypes in cattle

“…Currently, eleven genotypes of T. orientalis have been identified, types 1-8 and N1-N3 (Jeong et al, 2010;Khukhuu et al, 2011;Sivakumar et al, 2014). These genotypes are defined based on the sequences of the major piroplasm surface protein (MPSP), an immunodominant antigen expressed during several phases of the parasite's lifecycle (Sako et al, 1999). Of the eleven MPSP genotypes, Chitose (Type 1) and Ikeda (Type 2) have been associated with clinical disease (Cufos et al, 2012;Eamens et al, 2013b,c;McFadden et al, 2011); while the Buffeli type (Type 3) and its phylogenetic sister group, Type 5 are considered benign (Kamau et al, 2011a).…”

Epidemiological Survey of Theileria orientalis Infection in Grazing Cattle in the Eastern Part of Hokkaido, Japan

“…T. orientalis populations have recently been found to consist of seven types, based on a series of all the registered MPSP gene sequences [10,27]. Another gene, which encodes a 23-kDa piroplasm membrane protein, was also reported to show genetic diversity [18,28]. We therefore collected a total of 501 blood samples from 230 grazing cattle in the eastern areas of Hokkaido, Japan (Taiki, Otofuke, Shintoku, and Shin-Hidaka districts) in 2007 and 2008.…”