LECTURE #2 – INNATE IMMUNITY
After studying lecture #2, you should be familiar with the following concepts.
1. Self Versus Non-Self. During our lifetimes we face countless assaults from any
number of microbial, viral, parasitic and fungal invaders. Thus, an effective immune
system requires a detection system that can reliably discriminate between pathogenic
“non-self” cells without inducing immune responses against healthy “self” cells. As we
will see, there are two very distinct forms of this immune surveillance system.
2. Innate Immunity. The innate immune response is the first line of defense against
invading microbes and is the sole recognizable immune system in the overwhelming
majority of multicellular organisms. The entire repertoire of the innate immune system is
encoded within the germline and innate immune responses do not change upon repeat
exposure to an infectious or toxic agent. In innate immunity, microbial detection
proceeds through the recognition of generic microbial molecules (Pathogen Associated
Molecular Patterns (PAMPs)) by host Pattern Recognition Receptors (PRR).
3. Inflammation. Inflammation is an immediate consequence of PAMP detection by a
PRR. Inflammation involves reorganization of the vasculature at the site of infection to
permit the influx of leukocytes to the site of infection.
4. Macrophages. Macrophages are an i