Indirect immunofluorescence assay and confocal microscopy to localize the selected ES antigens by coimmunostaining of P. falciparum-infected erythrocytes. Air-dried infected erythrocytes were incubated with mouse antibodies specific to the selected proteins at 1:100 dilution (column 4; red). Rabbit PfMIF antibody was used as a co-localization marker (column 3; green). The parasite nuclei were stained with 4,6-diamidino-2-phenylindole (DAPI) (column 2; blue). Columns 1, 5, and 6 show a differential interference contrast (DIC) image, merged image, and differential interference contrast with merged image, respectively. Negative controls were performed using antibodies pre-incubated with the respective recombinant proteins before incubating with the fixed infected RBCs (column 7). Images by confocal microscopy showed punctate vesicle-like staining of the infected RBCs with all four (PfSEL1, PfSEL2, PfEK, and PfEP) antibodies with PfEK also showing specific rimlike staining of the plasma membrane of the infected RBC. PfMIF antibody was used each time as a marker for co-localization as PfMIF is exported via the Maurer clefts to the extracellular medium after schizont rupture. A partial co-localization of PfMIF was seen with each of the four proteins, suggesting a distinct pathway for the release of these ESAs.
Singh M, Mukherjee P, Narayanasamy K, Arora R, Sen SD, Gupta S, Natarajan K, Malhotra P. Proteome analysis of Plasmodium falciparum extracellular secretory antigens at asexual blood stages reveals a cohort of proteins with possible roles in immune modulation and signaling. Mol Cell Proteomics. 2009 8(9):2102-18
Other associated proteins
PFID | Formal Annotation |
---|---|
PF3D7_0931200 | selenoprotein |
PF3D7_1113100 | protein tyrosine phosphatase |
PF3D7_1121300 | tyrosine kinase-like protein |
PF3D7_1403600 | selenoprotein |