INTRACELLULAR HISTONE H2A IS RECOGNIZED BY CE AND OTHER PARASITOSIS IMMUNE SERA

AGUERO F; MAGLIOCO A; VALACCO P; JUAREZ VALDEZ A; PAULINO M; FUCHS A

Congreso; REUNIÓN DE SOCIEDADES DE BIOCIENCIAS 2021; 2021

Echinococcus granulosus (Eg) causes cyst echinococcosis (CE), aworldwide distributed parasitic disease that affects livestock and humans.Our laboratory has developed the EGPE cell line from bovineEg G1 protoscoleces (Echeverria et al, 2010) for studies of antiparasiticdrugs and identification of relevant molecules in diagnosisand treatment of CE. This work aimed to identify and characterizeproteins from Eg in the EGPE cells recognized by CE patients? sera.Materials and methods: total proteins extract from EGPE cells20 days grown was passed through a gel filtration column. Proteinfractions were concentrated through a 3K cut‐off membrane concentrator.Reactive fractions to Western Blot were passed throughaffinity columns with CE or other parasitosis patient?s sera. Then isolatedproteins were identified by proteomic in CEQUIBIEM (FCEyN,UBA). Proteins were modeled using Robetta platform (TrRosettamethod) and validated by molecular dynamics simulations with softwareNAMD 2.14. Epitope prediction was performed with IEDB (linearepitope prediction and Discotope 2.0) and ABCpred. Results:We identified Eg?s Histone H2A (W6U0N3, 195 aa) recognized bysera from CE and others parasitosis patients. W6U0N3 has 81%identity in the first 58 aa with Fasciola hepatica?s histone H2A. Generatedmodel was validated showing in 10-50 ns section of the trajectoryan averaged potential energy resultant -168208 ± 198 kcal/mol. This model presented two regions with different RMSD valuesfor the trajectory taking the averaged structure as reference: for 1-14aa region, 3.32 +/- 0.77 Å and for 14-195 aa region, 2.16 +/- 0.61Å. Linear epitopes were predicted in 123-138, 138-153 and 170-185 aa, meanwhile conformational epitopes were predicted in the1-14 aa region. Conclusion: Intracellular Histone H2A from EGPE