HTHSCI 3I03 Chapter Notes - Chapter 2: Natural Killer Cell, Hematopoietic Stem Cell, Innate Immune System
24 Mar 2015
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(3) innate immunity ii phagocytosis and natural killing. Recall that if pathogens do cross epithelial barriers, there are many innate immune cells directly under the epithelium of skin or mucosa. These cells act as gate keepers that immediately recognize pathogens via prrs (within 0-4 hours) These innate immune cells can destroy invaders at the site of entry. All blood and tissue immune cells originate from a single cell the pluripotent hematopoietic stem cell in the bone marrow. T cells develop in the bone marrow and travel to the thymus in order to mature. B cells develop and mature in the bone marrow. Nk cells develop in the bone marrow, but it is unclear whether or not they have to mature in the thymus (can mature in the absence of the thymus) Nb: monocytes and macrophages come from a granulocyte progenitor cell, but are agranular! Nb: granulocytes are termed polymorphonuclear because of their oddly shaped nuclei.
