NEW PROTEOME SCREANING METHODS USEFUL TO SENSITIVILY MONITOR NOVELSPECIFIC BIOMARKERS OF TLR-SPECIFIC SIGNALING WITH POTENTIAL IN DIAGNOSTIC AND DRUG TARGETING OF INFECTIOUS DISEASES

CRISTIAN JORGE ALEJANDRO ASENSIO; RODOLFO C GARCÍA

BUENOS AIRES

Congreso; LXII REUNIÓN ANUAL DE LA SOCIEDAD ARGENTINA DE INVESTIGACIÓN CLÍNICA (SAIC); 2017

SAIC

Abstract: There is a worrying paucity of research for the accurateidentification of intracellular protein biomarkers specific for the ligationof an individual receptor involved in immune and/or inflammatoryresponses. Finding them is complicated and failed so far due tothe intense crosstalk between the different inflammatory or immunereceptor pathways which share a plethora of adapter, scaffold andsignalling proteins, at multiple levels in several cell types. They alsoshare PTMs between proteins. Thus, we developed novel, potentprocedures to sensitively and systematically screen for proteomealterations in human macrophages infected with different bacteriaor stimulated with specific TLR2/4 ligands. We found many cytosolicproteins affected in their levels. One was a novel post-translationallygenerated, anionic form of a chaperone. It was always up-regulated(p=0.01, n=33) in the treatments and by 9-fold (p=0.05) in the peakingtime-point. Its level and temporal profile were reproducible afterbacterial infection or specific ligation of one TLR type but not the others.The results strongly suggest that its increment is not influencedby the ligand structure but only by the ligation act and by the ligand(s) concentration/half life. It was coreceptor-independent. Interestingly, its late-phase increment was sustained in time, still at day4 (7-fold). We propose models concerning novel PTM(s) accountingfor its reproducible pI change (p=0.01) and its spatio-temporal behaviour.The results suggest a role in a cytosolic complex associatedspecifically with its TLR TIR and rheostatically integrating the sustainedresponses (receptor trafficking, tolerance, degradation andautophagy). Its properties make this unique chaperone form an idealspecific biomarker suitable for future translational research orientedto diagnostics and receptor targeting in inflammatory, infectious andimmune diseases and also to vaccine development or validation.Keywords: TLR, proteome