CHAPTER 2 – INNATE IMMUNITY (FROM THE TEXT)
1. All multicellular organisms contain intrinsic mechanisms of defense against infections,
which constitute innate immunity.
2. The mechanisms of innate immunity respond to microbes and to nonmicrobial
substances, are specific for structures present on various classes of microbes, and are
not enhanced by repeat exposures to microbes.
3. TLRs, which are expressed on plasma membranes and in endosomes of many cell
types are a major class of innate immune system receptors that recognize different
microbial products including bacterial cell wall constituents and viral nucleic acids.
4. Epithelia provide physical barriers against microbes, produce antibiotics and contain
lymphocytes that may prevent infections.
5. The principal phagocytes, neutrophils and monocytes/macrophages are blood cells
that are recruited to sites of infection throu