Immune defence of mammals against bacterial pathogens - Anatomical defence; keeping microbes at a distance

7 important questions on Immune defence of mammals against bacterial pathogens - Anatomical defence; keeping microbes at a distance

Two major physical barriers

1. Mucus
2. Epithelium

Pattern recognition receptors (PRR)

Sense microbial content in the lumen and important in innate immune response by secretion of cytokines and chemokines.
- Recognize MAMP's (Microbe-associated molecular patterns).
- Expressed by enterocytes, Paneth cells and immune cells (DC's)

5 Ways in which the PRR signalling is regulated

1. TLR expression regulation
2. TLR localization
3. Apical and Basolateral differentiated signalling
4. Negative feedback regulation of NF-kB pathway
5. Attenuation of NF-kB activation by commensal bacteria
  • Higher grades + faster learning
  • Never study anything twice
  • 100% sure, 100% understanding
Discover Study Smart

TLR expression regulation

TLR's are expressed at low levels in the epithelial surfaces if there is no inflammation and highest expression in the crypts to protect stem cells

TLR negative feedback

Intracellular negative regulators that inhibit TLR signaling

Commensal bacterial TLR regulation

- Bacteroides thetatiotaomicron can induce the expression of negative regulators that for example promote the translocation of NF-kB from the nucleus.
- Salmonella can inhibit NF-kB pathway by bloking degradation of IkBa

Carpet wormhole effect

Formation of pores and eventually cell death by defensins

The question on the page originate from the summary of the following study material:

  • A unique study and practice tool
  • Never study anything twice again
  • Get the grades you hope for
  • 100% sure, 100% understanding
Remember faster, study better. Scientifically proven.
Trustpilot Logo