INVESTIGADORES
FARBER Marisa Diana
congresos y reuniones científicas
Título:
Characterization of Babesia bigemina perforin-like protein family
Autor/es:
PETRIGH R,; REGO N; VALENTINI B; SORIA M; MOSQUEDA J; NAYA H; ECHAIDE I; FARBER M
Lugar:
Zaragoza
Reunión:
Conferencia; http://www.higieneambiental.com/sites/default/files/images/pdf/Program-ttp7.pdf; 2011
Institución organizadora:
TTP7: Ticks and Tick-borne pathogens International Conference
Resumen:
Bovine babesiosis, cause
by Babesia bigemina and Babesia bovis, is a critical drawback to livestock
production in tropical and subtropical developing regions worldwide. In South America, both intraerythrocytic
protozoa are transmitted by Rhipicephalusmicroplus. Host-cell invasion mechanisms are fundamental
to spread infection in bovine host and tick vector. In spite of the relevance of host-cell
invasion pathways for the spread of infection, little is known about these
mechanisms in Babesia genera.A Previous
studies have reported a family of five paralogous genes in the genome of Plasmodium spp., encoding secreted
proteins containing membrane-attack complex/perforin (MACPF)-like domain. The
perforin-like 1 protein (PLP1) of P.
falciparum and Toxoplasma gondii are
localized into micronemas of sporozoites, organelles involved in host-cell infection.
Based on data from the annotated genomes of other apicomplexans(Plasmodium falciparum, Theileria annulata, Theileria parva and Babesia
bovis), we used bioinformatic tools
to identify, annotate and characterize eight genes containing MACPF domain in B. bigemina from the available sequences
of the B. bigemina genome.
Transcriptional studies
using RT-PCR showed that all plp
genes are transcribed in the intraerythrocytic stage. However, the
transcriptional level analysed by qPCR revealed that plpe and plpb genes have
significantly higher transcriptional rates, which might suggest that specific PLP proteins are required to reach its function in the parasite egress from
erythrocyte.
On the other hand, the plpa gene sequence analysis showed the
presence of a secretion signal and a polymorphic repetitive region among
different B. bigemina isolates. To explore whether this region might
represent an adaptation to immune selection pressure, we produced a recombinant
PLPA (rPLPA) to test it against bovine sera. The prediction of the signal peptide together with the specific reaction
of bovine sera against rPLPA might
suggest that PLPA is being exported to the erythrocyte membrane. Besides, we
demonstrated PLPA expression in intraerythrocytic stage by an indirect
immunofluorescence assays using specific mice sera obtained against rPLPA. Further
studies should be performed to demonstrate
PLPA role in parasite exit mechanism from erythrocyte.