title: Host-parasite interaction: selective Pv-fam-a family proteins of Plasmodium vivax bind to a restricted number of human erythrocyte receptors.
abstract: BACKGROUND
  Plasmodium vivax synthesizes the largest number of 36 tryptophan-rich proteins belonging to the Pv-fam-a family. These parasite proteins need to be characterized for their biological function because tryptophan-rich proteins from other Plasmodium species have been proposed as vaccine candidates.
  
  
  METHODS
  Recombinant P. vivax tryptophan-rich antigens (PvTRAgs) were used to determine their erythrocyte-binding activity by a cell-based enzyme-linked immunosorbent assay, flow cytometry, and a rosetting assay.
  
  
  RESULTS
  Only 4 (PvTRAg26.3, PvTRAg34, PvTRAg36, and PvTRAg36.6) of 21 PvTRAgs bind to host erythrocytes. The cross-competition data indicated that PvTRAg36 and PvTRAg34 share their erythrocyte receptors with previously described proteins PvTRAg38 and PvTRAg33.5, respectively. On the other hand, PvTRAg26.3 and PvTRAg36.6 cross-compete with each other and not with any other PvTRAg, indicating that these 2 proteins bind to the same but yet another set of erythrocyte receptor(s). Together, 10 of 36 PvTRAgs possess erythrocyte-binding activity in which each protein recognizes >1 erythrocyte receptor. Further, each erythrocyte receptor is shared by >1 PvTRAg.
  
  
  CONCLUSIONS
  This redundancy may be useful for the parasite to invade red blood cells and cause disease pathogenesis, and it can be exploited to develop therapeutics against P. vivax malaria.
authors.affiliation: Department of Biotechnology, All India Institute of Medical Sciences, New Delhi.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Zeeshan
authors.affiliation: Department of Biotechnology, All India Institute of Medical Sciences, New Delhi.
authors.forename: Rupesh Kumar
authors.initials: RK
authors.lastname: Tyagi
authors.affiliation: Department of Biotechnology, All India Institute of Medical Sciences, New Delhi.
authors.forename: Kriti
authors.initials: K
authors.lastname: Tyagi
authors.affiliation: Department of Biotechnology, All India Institute of Medical Sciences, New Delhi.
authors.forename: Mohd Shoeb
authors.initials: MS
authors.lastname: Alam
authors.affiliation: Department of Biotechnology, All India Institute of Medical Sciences, New Delhi.
authors.forename: Yagya Dutta
authors.initials: YD
authors.lastname: Sharma
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D002460:Cell Line; D003412:Cricetulus; D004797:Enzyme-Linked Immunosorbent Assay; D004912:Erythrocytes / Q000276:immunology / Q000378:metabolism* / Q000469:parasitology; D005260:Female; D018503:Genome, Protozoan / Q000235:genetics; D006790:Host-Parasite Interactions; D006801:Humans; D016780:Malaria, Vivax / Q000097:blood / Q000276:immunology / Q000469:parasitology*; D010966:Plasmodium vivax / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011485:Protein Binding; D015800:Protozoan Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D017422:Sequence Analysis, DNA; D014364:Tryptophan / Q000378:metabolism
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D015800:Protozoan Proteins; D011994:Recombinant Proteins; D014364:Tryptophan
keywords: host cell invasion; malaria parasite; receptor-ligand interaction; tryptophan-rich proteins