HOST-PARASITE INTERPLAY

Transcription

1 HOST-PARASITE INTERPLAY Adriano Casulli EURLP, ISS (Rome, Italy) HOST-PARASITE INTERPLAY WP3 (parasite virulence vs human immunity) (Parasite) Task 3.1: Genotypic characterization Task 3.6: Transcriptome analysis (Human) Task 3.2: HLA class I and II polymorphisms Task 3.3: KIR gene polymorphisms Task 3.4: HLA-G polymorphism Task 3.5: Proteomic analysis 1

2 GOOD REASONS TO WORK ON WP3 The variability of clinical evolution and the unpredictability of the therapeutic response of CE suggest that an immunogenetic heterogeneity might underpin this clinical heterogeneity. We will combine these studies in both parasite and CE human host, arguing that the WP3 could provide insights on clinical course of disease, and may be predictive of the efficacy of a drug-based treatment. The main aim of WP3 is to identify factors related to the CE pathogenicity. TASK 3.1: EGC HAPLOTYPES/GENOTYPES/SPECIES CHARACTERIZATION (MONTHS 1-36) Primer walking technique will be used to obtain the long nucleotidic sequence of the entire mitochondrial gene cytochrome c oxidase subunit 1 (Cox1; 1611 base pairs). Related amino-acid sequences will be inferred from the nucleotide sequences by mitochondrial echinoderm genetic code in order to characterize the Egc haplotypes (within Egss) and genotypes/species (within Egc). 2

3 TASK 3.2: HLA CLASS I AND II POLYMORPHISMS HLA (Human Leukocyte Antigens) class I and II genomic typing will be performed by PCR-SSP or revpcr-sso techniques. Useful information are expected on the role of adaptive immune response molecules, as peptide presenters, in infection s evolution. Moreover, the study of HLA class I, as ligands of NK receptors, will explain the interaction with the innate immune response pathway which is responsible for the early response to infection. TASK 3.3: KIR GENE POLYMORPHISMS KIR (Killer cell Immunoglobulin-like Receptors) molecular typing will be performed using the low resolution PCR-SSP assay to identify 14 KIR genes and 2 pseudogenes. This study has never been undertaken so far although potentially meaningful, as the KIR genes regulate the transcription of inhibitory/activatory receptors expressed on NK cells. 3

4 TASK 3.4: HLA-G POLYMORPHISM Genotyping of the 14-bp ins/del polymorphism in the exon 8 of the non classical HLA-G gene by PCR-SSP technique. HLA-G phenotypes will be important to select people with a tolerogenic phenotype which is the basis for long standing infection and chronicity. TASK 3.5: PROTEOMIC ANALYSIS Measure the soluble HLA-G, KIR2DS4 and KIR3DL1 proteins levels in plasma of patients at different CE infection stages and in control persons by ELISA. The proteomic assay, applied to soluble HLA-G and KIR serum levels in different sets of patients, is a novel approach and opens a promising and meaningful scenario. 4

5 TASK 3.6: TRANSCRIPTOME ANALYSIS Transcriptome sequencing using NGS technologies is a fast and reliable method to identify genomic information of organisms. total RNA purification > transcriptome sequencing > in-silico analysis > annotation. ESTs will be analysed and compared with the variation of the hepatic cystic stages and with results coming from Tasks Candidate genes involved in the heterogeneity of CE clinical pictures will be further studied. Identify the molecular bases related to the pathogenicity of this disease. HUMAN IMMUNITY (genomic, proteomic) PARASITE VIRULENCE (genomic, proteomic/trancriptomic) CLINICAL PICTURE WP3 5