Characterization and vaccine potential of a novel recombinant coccidial antigen

Abstract

A cDNA clone derived from sporulated oocysts of Eimeria tenella and encoding the expression product GX3262 was identified using a monoclonal antibody (12-09) raised against Eimeria acervulina sporozoites. The cDNA fragment containing the coccidial antigen gene was cloned in bacteriophage lambda gtl 1, transferred to a plasmid, and introduced into Escherichia coli for analysis of the gene products. The strain carrying the plasmid produced GX3262 as part of a fusion protein consisting of the first 1,006 amino acids of E. coli

Eimeria tenella‐specific Chicken T‐Cell Clones Reactive to an Internal Image Anti‐Idiotypic Antibody: Correlation between Biological Activities and Protective Cell‐Mediated Immunity

“…clones from SC {B2/B2), and SC Bursectomized (Bx) chickens that had recovered from repeated E. tenella infections were generated in vitro by stimulating splenic lymphocytes (Bhogal et al 1986). Their in vitro functional characteristics (Bhogal et al 1986(Bhogal et al , 1989a, and their interactions with an internal image anti-idiotypic antibody (Bhogal et al, in preparation) have been defined. At present, because of a lack of reagents with which to identify phenotypic markers similar to those known for the mammalian T cells, we have classified different T-cell clones according to their functional activities.…”

“…Even though the morphological characterization of different life cycle-stages of Eimeria parasites has been well-documented (Levine 1982), an immunological profile of the antigens in morphologically distinct developmental stages is not well-characterized. The surface membrane proteins of the sporozoites, the infective stage of the parasite, contain some tandem repeat epitopes (Miller et al 1989a), and the antigenic profile appears to be complex and different from that of the Plasmodium falciparum sporozoite which has been shown to consist of two highly conserved regions (region 1 and II) and a central repetitive region which forms the immunodominant B-cell antigenic site (Dame et al 1984). Immunochemical studies have defined a range of polypeptides with diverse molecular weights on the surface of E. tenella sporozoites (Murray et al 1985, Wisher 1986.…”

“…Such immune mechanisms seem to be operational in the intestinal luminal walls of the chickens that have recovered from natural or experimental infections (Horton-Smith et al 1963a, Leathem & Burns 1967, Mesfin & Bellamy 1979. Studies using monoclonal antibodies (Danforth & Augustine 1983) or parasite-specific cloned T cells (Bhogal et al 1986(Bhogal et al , 1989a suggest cross-reacting antigens in the early developmental stages of the BHOGAL parasite. Consistent with this, a recombinant E. tenella sporozoite antigen with ability to engender protective immunity against experimental E. tenella (Miller et al 1989a) and E. acervulina (Bhogal et al , 1989c infections have been reported, but the immunobiology of this antigen with resp>ect to its T-and B-cell epitopes is not we 11-characterized.…”

“…Studies using monoclonal antibodies (Danforth & Augustine 1983) or parasite-specific cloned T cells (Bhogal et al 1986(Bhogal et al , 1989a suggest cross-reacting antigens in the early developmental stages of the BHOGAL parasite. Consistent with this, a recombinant E. tenella sporozoite antigen with ability to engender protective immunity against experimental E. tenella (Miller et al 1989a) and E. acervulina (Bhogal et al , 1989c infections have been reported, but the immunobiology of this antigen with resp>ect to its T-and B-cell epitopes is not we 11-characterized. Identification and characterization of another recombinant antigen, a 22-21 KDa complex in the surface of the sporozoite membranes, has also been reported (Profous-Juchelka et al 1988).…”

“…However, the possibility of controlling the disease with other than chemotherapy or a live vaccine using virulent parasites had largely been dismissed (Horton-Smith et al 1963b, Rose & Long 1980, Davis 1981, Rose 1987. Recent work has, nonetheless, suggested the feasibility of a molecular vaccine (Murray et al 1985, Paul et al 1987, Bhogal et al 1988, 1989c, Miller et al 1989a.…”