Heterologous expression of Cryptosporidium parvum vaccine candidate GP60 i

ELGUERO, MARÍA E.; TOMAZIC, MARIELA L; MONTES, GUADALUPE; CHAIN CAROLINA; NUDEL, CLARA; SCHNITTGER, LEONHARD; NUSBLAT, ALEJANDRO D.

Camerino

Conferencia; Conference on Ciliate Molecular Biology 2015; 2015

Several surface proteins are attached to membranes by Glycophosphatydilinositol (GPI) anchor in eukaryotic cells. Free GPI-anchors are normally present in the plasma membrane and proteins are covalently bound to them after a post-translational modification occurring in the ER and Golgi. In ciliates, such as Tetrahymena and Paramecium, i-antigen proteins, which are called immobilization antigens based on their immunological properties, represent most of the GPI-anchor proteins expressed in the membrane. We have isolated enriched fractions of GPI protein from T. thermophila by Triton X-114 phase-partitioning procedure and two major proteins were detected, SerH and one uncharacterized protein (TTHERM_01125120). They both seemed to be GPI anchored proteins according preliminary in silico and in vitro analysis.Prominent vaccine candidates of many pathogenic apicomplexan protozoans are surface proteins containing GPI anchors. The parasite Cryptosporidium causes diarrheal disease worldwide. The GP60 (gp40/15) GPI anchor protein of Cryptosporidium sp is implicated in mediating infection of host cells. Proteolytic processing of the protein to glycopeptides (gp40 and gp15) has a significant role for host cell invasion. We could achieve episomal expression of GP40/15 antigen from Cryptosporidium parvum in whole cell of T. thermophila. We have also detected that the ciliate is capable of processing the cleavage of the 70 KDa GP60 into 40 KDa protein by unknown protease.