Canonical and non-canonical Wnt signaling in hematopoiesis and lymphocyte development

Abstract

The immune system of mammals is responsible for protecting our body against pathogens

and foreign substances (antigens), and it consists of two discrete lines of defense. The first

line called innate immunity and provide a quick and nonspecific defense. The innate immunity includes different cells types, such as mast cells, macrophages, neutrophils, eosinophils, dendritic cells and natural killer (NK) cells. The second line of defense called adaptive immunity responds in an antigen-specific manner, and comprised of B and T lymphocyte cells. This thesis focuses on one of the signals which are known to play an important role during HSC repopulation and T cell development that is Wnt signaling pathway. Depending on the tissue/cell types (microenvironment) and specific class of Wnt proteins binding to the corresponding receptors on the developing lymphocytes, two discrete downstream pathways will be activated namely canonical or non-canonical Wnt pathway. The main aim of this thesis is to dissect the roles of these two distinct pathways during hematopoiesis and lymphocyte development in murine as a physiologically relevant animal model.