Cloning and expression of a rhoptry associated protein of P. fal

Details Cloning and expression of a rhoptry associated protein of P. fal Cloning and expression of a rhoptry associated protein of P. fal

1993-04-01

1996-11-12

Cunningham, Thomas M.

Chemistry: molecular biology and microbiology

Micro-organism, per se ; compositions thereof; proces of...

Bacteria or actinomycetales; media therefor

4242681, 4242721, 435 693, 4352528, 4353201, 530350, 530395, 530806, 536 235, C12N 121, C07H 2104, C07K 14445

Patent

active

055739431

DESCRIPTION:

BRIEF SUMMARY
This invention relates to the cloning of the gene encoding a rhoptry associated protein of Plasmodium falciparum, to the recombinant polypeptide produced by expression of this gene in a host cell, and to the use of this recombinant polypeptide in a vaccine against the malaria parasite.
In many parts of the world, malaria is proving refractory to control measures aimed at the vector and the parasite. Advances in molecular biology have opened up the possibility of augmenting existing control programmes with vaccines directed against the parasite. Several stages in the life cycle of the parasite are under intense scrutiny as targets of such putative vaccines; these include the sporozoite coat protein, various proteins found in the asexual erythrocytic blood stages and proteins on the surface of the mosquito stages (Miller et.al., 1986).
The stage of the parasite which invades erythrocytes is the merozoite. At this stage, there are has a pair of organelles at the apical end of the parasite, the rhoptries, that are involved in the invasion process. During invasion the contents of the rhoptries are discharged through ducts and may play an initial role in the formation of the developing parasitophorous vacuole. Antigens in the rhoptry contents were amongst the first components identified as potential vaccine candidates. Freeman et.al. (1980) showed that a monoclonal antibody against a protein found in the rhoptries of the rodent malaria Plasmodium yoelii was able to confer passive protection in mice challenged by an otherwise lethal strain of P. yoelii. The target of this monoclonal antibody was purified and shown to induce active protection upon immunization (Holder and Freeman, 1981).
The rhoptries of the human malarial parasite P.falciparum have been intensively studied and many proteins have been found which are associated with the rhoptries or associated apical organelles. These include: a 225 kDa antigen (Roger et.al., 1988), a complex consisting of proteins of about 140, 130 and 105 kDa (Campbell et.al., 1984; Holder et.al., 1985; Siddiqui et.al., 1986; Cooper et.al., 1988), a complex consisting of an 80 and a 42 kDa protein (Perrin and Dayal, 1982; Campbell et.al., 1984; Howard et.al., 1984; Schofield et.al., 1986; Clark et.al., 1987; Bushell et.al., 1988), a phospholipase activated protease (Braun-Breton et.al., 1988) and individual proteins of about 80 kDa (Peterson et.al., 1989; Crewther et.al., 1990) and 55 kDa (Smythe et.al., 1988).
The reported sizes of the components of the 80/42 kDa complex (referred to as QF3 by Schofield et.al.(1986) and Bushell et.al., (1988)) have varied from 80 to 82 kDa and 40 to 42 kDa. In some studies, an 83 kDa, short-lived precursor of the 80 kDa; a series of breakdown products of the 80 kDa; and a 40 kDa derivative of the 42 kDa protein have been reported (Bushell et.al., 1988). In the following description, the complex will be referred to as QF3 but following the nomenclature of Ridley et.al. (1990a), the 80 kDa component will be referred to as RAP-1 (Rhoptry Associated Protein 1) and the 42 kDa component as RAP-2 (Rhoptry Associated Protein 2).
There are several published reports suggesting that the QF3 complex is a likely candidate for a vaccine against P.falciparum. Monoclonal antibodies directed against QF3 give marked inhibition of parasite growth in vitro (Schofield et.al., 1986). Ridley et.al., (1990b) found that a mixture of affinity purified RAP-1 and RAP-2 was able to immunize Saimiri monkeys. These monkeys developed antibodies against both RAP-1 and RAP-2 and showed substantial protection when challenged with P.falciparum. Perrin et.al., (1985) also obtained substantial protection in Saimiri monkeys following immunization with mixtures containing either 80 and 40 kDa rhoptry proteins or with mixtures of several 40 kDa rhoptry proteins. The interpretation of these results is complicated since the proteins were purified using a mixture of 3 monoclonal antibodies. These now appear to be directed against several different proteins including aldolase (Certa et.al

REFERENCES:
Perrin, L. H. et al., J. Clin. Invest. 75:1718-1721 (May, 1985), "Immunization with a Plasmodium falciparum merozoite surface antigen induces a partial immunity in monkeys".
Bushell, G. R., et al., Mol. Biocehm. Parasitol. 28:105-112 (1988), "an antigenic complex in the rhoptries of Plasmodium falciparum".
Clark, J. T., et al., Parasitol. Res. 73(5): 425-434 (1987), "Identification and charaterisation of proteins associated with the rhoptry organelles of Plasmodium falciparum merozoites".
Coppel, R. L., et al., Mol. Biochem. Parasitol. 25:73-81 (1987), "A cDNA clone expressing a rhoptry protein of P. falciprum".
Cox, F. E. G., Tibtech 9:389-394 (Nov., 1991), "Malaria vaccines-progress and problems".

Affiliated with

Also associated with

Rating

Cloning and expression of a rhoptry associated protein of P. fal does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Cloning and expression of a rhoptry associated protein of P. fal, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cloning and expression of a rhoptry associated protein of P. fal will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-561897