Class notes
Key points you need for toll like receptors
- Course
- PTMDMMED-3SF
- Institution
- Trinity College
Toll-Like Receptor role in infection and inflammation, diversity and redundancy.
[Show more]
Seller
Follow
Content preview
Toll-like ReceptorsTLR 1,2, 6
Recognises lipid and carbs – lipoproteins, glycolipids, on gram
positive bacterial cell wall
"TLR2:TLR2" - homodimerization of TLR2, meaning that two TLR2
molecules pair up to form a functional receptor complex.
Ligands: peptidoglycan, lipoteichoic acid (LTA), and
mycobacterial lipoprotein from mycobacteria.
TLR1:TLR2
triacylated lipoproteins, M tuberculosis
TLR2:TLR6
diacylated lipoproteins and LTA.
TLR2:Dectin 1 - cooperative interaction between TLR2 and Dectin 1,
Beta-glucans, components of yeast cell walls.
These different pairings of TLR2 with either itself or with other
receptors like TLR1, TLR6, or Dectin 1 allow the immune system to
detect a wide range of microbial components.
TLR 4
Recognises LPS form gram negative bacteria
Also taxol (anti-tumour agent), HMBG1 (released by dying cells),
fibrinogen
May contribute to sepsis (hyperinflammatory response) – mice with
TLR4 knock out resistant to disease
TLR 5, 10
TLR 5 – flagellin from gram positive and gram negative bacteria
TLR 10 – influenza viruses by sensing viral rna-protein complex
, TLR3,7,8,9
All located in endosomes/lysosomes
3 – viral double stranded rna
7,8 – viral ssRNA (eg. Influenza)
9 – viral dna, bacterial dna with unmethylated CpG motif
All induce the type 1 IFN response – viral infection
Role of TLR in infectious disease
Autosomal recessive IRAK-4 deficiency: This deficiency leads to
a condition where patients' cells do not respond to ligands for TLR1-
6 and TLR9, nor do they respond well to the cytokines IL-1 and IL-
18. This results in a poor cytokine response when stimulated with
whole bacteria. IRAK-4 (Interleukin-1 Receptor-Associated Kinase 4)
is a kinase that plays an essential role in the TLR signaling pathway.
Increased susceptibility to infections: Patients with IRAK-4
deficiency are particularly susceptible to a narrow spectrum of
infections, especially from bacteria like Streptococcus
pneumoniae and Staphylococcus aureus, which are common
in early childhood.
Similar phenotype with MyD88 deficiency: Individuals
with a deficiency in MyD88 (Myeloid differentiation primary
response 88), another crucial adaptor protein in TLR signaling,
exhibit a similar susceptibility to infections, including those
caused by Pseudomonas aeruginosa.
Thus, it is not because of alterations to TLR/IRK signalling pathway
that lead to resistance to many microorganisms as an alternative
way can restore the function
Autosomal dominant tlr3 deficiency – increase susceptibility to
hse (herpes)
Tuberculosis
Mtb is spread by aerosol droplets which are inhaled into the
alveoli of the lungs
Alveolar macrophages phagocytose mycobacteria through
receptors
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller ngni2312. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $8.57. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
72042 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now