High immunogenecity and erythrocyte-binding activity in the tryptophan-rich domain (TRD) of the 74-kDa Plasmodium vivax alanine-tryptophan-rich antigen (PvATRAg74)

Alam, Mohammad Tauqeer ; Bora, Hema ; Singh, Neeru ; Sharma, Yagya D. (2008) High immunogenecity and erythrocyte-binding activity in the tryptophan-rich domain (TRD) of the 74-kDa Plasmodium vivax alanine-tryptophan-rich antigen (PvATRAg74) Vaccine, 26 (31). pp. 3787-3794. ISSN 0264-410X

Full text not available from this repository.

Official URL: http://www.sciencedirect.com/science/article/pii/S...

Related URL: http://dx.doi.org/10.1016/j.vaccine.2008.05.059

Abstract

Plasmodium vivax is the most widespread species of human malaria parasite affecting 70-80 million people worldwide each year. In recent years, some potential vaccine candidate antigens from P. vivax have been identified including tryptophan-rich antigens PvTRAg and PvTARAg55. We report here the identification and partial characterization of a 74 kDa P. vivax alanine-tryptophan-rich antigen (PvATRAg74) which is expressed by all asexual blood stages of the parasite. This protein contains two major domains, i.e. alanine-rich domain (ARD) in N-terminal region and the tryptophan-rich domain (TRD) at C-terminus. PvATRAg74 also contains variable numbers of octa-peptide repeats in the ARD region. The C-terminal PvATRAg74 containing TRD was highly conserved among 32 P. vivax isolates while N-terminal ARD showed genetic polymorphisms. The 36 kDa TRD was expressed in E. coli and named here as His6-TRD. The purified recombinant His6-TRD showed binding with uninfected human erythrocytes. This antigen was also recognized by all 38 P. vivax patients' sera on ELISA thus showing a very high seropositivity rates. In vitro stimulation of lymphocytes with purified His6-TRD indicated that it induced T cell immune response in majority (94%, n=16) of P. vivax exposed individuals. The stimulated T cells produced higher amount of IL-4 and IL-10 than IFN-γ, TNF-α, and IL-12 indicating a Th2 type of response bias. Unlike PvTARAg55, this antigen is more immunogenic in humans and possesses the erythrocyte-binding activity. Immunogenecity of PvATRAg74 is similar to PvTRAg whose erythrocyte-binding activity still remains unknown.

Item Type:Article
Source:Copyright of this article belongs to Elsevier Science.
Keywords:Plasmodium vivax; Tryptophan-rich Antigen; Vaccine Candidate
ID Code:48645
Deposited On:15 Jul 2011 07:58
Last Modified:15 Jul 2011 07:58

Repository Staff Only: item control page