Innate Immunity

What is innate immunity?

It’s the body’s first line of defense that acts quickly and recognizes general patterns on pathogens.

Name the 3 types of external barriers in innate immunity.

Mechanical, Biochemical, Microbiota

Give examples of mechanical barriers.

Skin, mucus, cilia lining the respiratory tract

Give examples of biochemical defenses

Psoriasin (skin), Lysozyme (tears), α-defensin (GI), β-defensin (skin)

What are commensal microbes?

Friendly microbes that live on skin and in the gut; they compete with pathogens.

They provide defense by preventing the colonization of harmful pathogens.

Name 5 effector cells in innate immunity

Neutrophils, Macrophages, Monocytes, NK cells, Dendritic cells

What are the 4 main effector mechanisms used by innate immune cells?

Phagocytosis, Oxidative attack, Non-oxidative attack, Antigen presentation

What are PRRs (Pattern Recognition Receptors)?

Receptors that detect common microbial structures called PAMPs. They are a type of PRR that sits on or inside immune cells

What do TLR2 and TLR4 detect?

TLR2 – Gram-positive bacteria; TLR4 – LPS on Gram-negative bacteria

What are PAMPs?

Pathogen-associated molecular patterns that are recognized by the immune system (PRR). They are a small part of microbes, they help the body know something is foreign and trigger an immune responses

What protein on the skin kills E. coli and prevents colonisation?