Human Immunity and Blood

Myeloperoxidase is most abundantly expressed in neutrophil granulocytes.

Clotting factor XIII or fibrin stabilising factor refers to the blood clotting factor that helps in stabilising the final blood clot or fibrin.

These are of the myeloid lineage which are separated from the monocyte-macrophage lineage after the pluripotent stem cell stage.

Dendritic cells (DCs) are antigen-presenting cells (also known as accessory cells) of the mammalian immune system. There are several types of dendritic cells, well distributed over the body.

B lymphocytes secrete antibodies and cytokines and are responsible for antigen specific humoral responses. They can process and digest antigens particularly in secondary immune responses but do not have a major phagocytic role.

Endothelial cells are not essentially phagocytic although they do contribute by the production of mediators of the inflammatory process, particularly acute inflammation and were previously lumped together with the mononuclear phagocyte system in what was known as the reticuloendothelial system (RES).

T-lymphocytes are specialised for recognising peptides derived from intracellular infectious agents which are exhibited on the surface of an infected cell together with MHC class I & II molecules.

Gamma-interferon activates microbicidal mechanisms within the macrophage, thereby leading to the death of intracellular parasites.

Lymphocytes are not phagocytic, irrespective of their activation status.

They are circulating immature macrophages or dendritic cells.

B-lymphocytes have antibodies on their cell surface which act as an antigen receptor. Upon activation, they differentiate into plasma cells which secrete large amounts of antibodies.

Plasma cells produce immunoglobulins of all isotypes, including IgE.

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