The Potential of Cysteine Protease-encoding-gene as Candidate for DNA Vaccine against Plasmodium Berghei Infection in Mice.
ABSTRACT
The potential of cysteine protease-DNA -vaccine- constructs to protect mice against Plasmodium berghei infection was investigated.
The full-length genes encoding the orthologs of falcipain-1 and falcipain-2 were identified in the database, isolated and amplified by a nested polymerase chain reaction (PCR) using the genomic DNA of a rodent malaria parasite, Plasmodium berghei, as template.
The oligonucleotides used to prime the PCR were designed based on the identified contigs at the Welcome Trust Sanger Institute containing the entire cysteine proteases reading frames.
The gel purified amplicons were cloned into pcDNA3AmpStrepTag vector and the presence of the genes in positively transformed XL1-Blue E. coli strain were confirmed via colony PCR, restriction digest and sequencing.
The Berghepain-1 (BP1) and Berghepain-2 (BP2) genes amplified contain 1560 bp and 1407 bp open reading frames encoding 519 and 468 amino acids with molecular masses of 60.31 kDa and 54.46 kDa, and isoelectric points of 7.52 and 6.01, respectively.
Sequence analyses and alignments showed that both deduced proteins belong to peptidase_C1 superfamily, lacked signal peptides and possess high identity (up to 78%) with their corresponding cysteine protease.
INTRODUCTION
Malaria is a life-threatening parasitic disease caused by various species of plasmodia and is transmitted via the bite of mosquitoes. It is thought to be man’s most important parasitic disease.
According to the World Health Organization there are 300 to 500 million clinical cases of malaria each year resulting in 1.5 to 2.7 million deaths (IDR centre report, 1996) with SubSaharan Africa known to be the region with the highest malaria infection rate.
In fact, it is reported that 80 -90 % of malarial deaths occur in this region (IDR centre report, 1996). Four plasmodium species (Plasmodium falciparum, Plasmodium vivax,
Plasmodium malariae and Plasmodium ovale) are responsible for malaria infection among human with P. falciparum infection accounting for most of the death cases encountered (Orjih, 2005) that is why research efforts on malaria has focused largely on P. falciparum.
Plasmodium berghei is a causative agent of rodent malaria and usually presents similar cerebral infection equivalent to that by P. falciparum in human (Albay et al., 1999).
The major features of P. berghei infection are anaemia, splenomegaly, fever and liver damage (Thurston, 1953; Sudhir and Saxena, 1980;). The management of malaria requires the use of chemotherapeutic substances.
Chloroquine and sulfodoxine-pyrimethamine are two of the commonly used antimalarial drugs. In recent time, however, drug toxicity and the increasing incidence of drug resistance (Rosenthal, 1998; Ekland and Fidock, 2007)
have constituted the major challenges facing chemotherapeutic efforts against malarial infection and the molecular basis for this resistance is still highly speculative which makes it difficult to develop countermeasures (Salganik et al., 1987).
REFERENCES
Albay, C., Yucel, A., Ceber, K., Imir, T. (1999). The in vitro effect of Plasmodium berghei
antigen lysate on Natural Killer (NK) cell cytotoxic Activity. Tr. J. of Med. Scie. 29:253-258.
Aly A.S.I., and Matuschewski K. (2005). A malarial cysteine protease is necessary for
plasmodium sporozoites egress from oocysts. The J. of Exp. Med. 202(2):225-230.
Anderson, S., Davis, D.L., Dahlback, H., Jornvall, H., and Rusell,. D.W. (1989). Cloning,
structure, and Expression of Mitochondrial Cytochrome p-450 Sterol 26-Hydroxylase, a
bile acid Biosynthetic Enzyme. J. Biol. Chem. 264. 8222-8229.
Andrews, K.T., Tran, T.N., Fairlie, D.P. (2012). Towards histone deacetylase inhibitors as new
antimalarial drugs. Curr Pharm Des. 18 (24):3467-79.
Aravind, L., Lakshminarayan M. Iyer, Thomas E. Wellems, and Louis H. Miller (2003).
Plasmodium Biology: Genomic Gleanings. Cell. 115:771-785.
Bloland, P.B., Ettling, M., and Meek, S. (2000). Combination therapy for malaria in Africa: hype
or hope? Bulletin of the World Health Organization. 78 (12):1378-1388.
Boncertz, V., and Hungerer, K. D. (1978). Trypanosoma cruzi: Isolation and Characterization of
a Protease. Experimental Parasitology 45:8-18.
Bolivar, F., Rodriguez, R.L., Betlach, M.C., and Boyer, H.W. (1977a). Construction and
Characterization of a New Cloning Vehicles. I. Ampicilin-Resistant Derivatives of the
Plasmid pMB9. Gene. 2:75-93.
Bolivar, F., Rodriguez, R.L., Greene, P.J., Betlach, M.C., Heyneker, H.L., and Boyer, H.W.
(1977b). Construction and Characterization of a New Cloning Vehicles. II. A
Multipurpose Cloning System. Gene. 2:95-113.
StudentsandScholarship Team.
Be the first to comment