NATS 1730 Lecture Notes - Lecture 1: Mast Cell, Neutrophil, Interleukin 10
17 Dec 2016
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Document Summary
The immune system distinguishes self from nonself and eliminates potentially harmful nonself molecules and cells from the body. The immune system also has the capacity to recognize and destroy abnormal cells that derive from host tissues (see tumor immunology). Any molecule capable of being recognized by the immune system is considered an antigen (ag). The skin, cornea, and mucosa of the respiratory, gi, and gu tracts form a physical barrier that is the body"s first line of defense. Some of these barriers also involve immune functions and other active defenses: Outer, keratinized epidermis: keratinocytes in the skin secrete antimicrobial peptides (defensins), and sebaceous and sweat glands secrete microbe-inhibiting substances (eg, lactic acid, fatty acids). Also, many immune cells (eg, mast cells, intraepithelial lymphocytes, ag-sampling langerhans" cells) reside in the skin. Mucosa of the respiratory, gi, and gu tracts: the mucus contains antimicrobial substances, such as lysozyme, lactoferrin, and secretory iga antibody (siga).
