In vitro Ly6Chigh monocyte generation as a novel tool for a infalmatory diseases research = Generación In vitro de monocitos LyC6high para el estudio de enfermedades inflamatorias

Abstract

Monocytes are composed of several subsets which differ in sizes, morphology, ontogeny, localization, gene expression, fates and functions. Two principal and functionally distinct subsets have been identified in human, mice and other species. Monocytes are key players of the innate immune system. Their implication in the early events of inflammation makes them extremely attractive to uncover the initial processes that drive multiple pathologies. In this study we present a technique for in vitro generation of Ly6Chi monocytes produced in vitro.

Initially, we demonstrated that in vitro generated monocytes showed a high degree of similarity with the natural Ly6Chi monocyte population found in the blood stream of mice. The integration of FACS and real-time PCR data determined that Ly6Chi cells and peripheral blood Ly6Chi monocytes present equivalent surface markers and also confirmed the plasticity of Ly6Chi cells indicating their potential modulatory effects during inflammation. FACS data also confirmed that Ly6Chi cells were capable to differentiate, maturate and activate in vitro.

Subsequently, our aim was to evaluate the migratory and differentiation capacities of Ly6Chi cells in vivo. Taking together all our results, we confirmed the infiltration capacity of in vitro-derived Ly6Chi monocytes as well as their ability to differentiate into recruited macrophages in vivo.

Finally, we tested the impact that administration of Ly6Chi cells may have in the inflammation onset and progression in several in vivo models. We decided to evaluate this effect in two mice models of acute inflammation, the dinitrofenolbenzene contact-induced hypersensitivity model (DNFB model) and the Notexin-induced myoinjury model (NTX model). We decided as well to evaluate the effect of Ly6Chi cells administration in a model of septic infection with Klebsiella pneumoniae (KP model) and the chronic inflammatory model of experimental autoimmune encephalopathy (EAE model).

In conclusion, considering the obtained results from this experimental project we can affirm the phenotypical, migratory and differentiation capacities of in vitro-generated Ly6Chi monocytes. Ly6Chi cells are able to induce changes in pathology progression.