Toll Like Receptors

[IMMUNOLOGY] July 20, 2010 1 A sample copy of Biology4You| http://aleenabioinfo.webs.com TOLL LIKE RECEPTORS Derived from the Greek word, Toll meaning : Weird or Wizard Discovered in Drosophila Kind of Pattern Recognition Receptor ( PRR ) Innate Immune System A pattern recognition pattern and acting as signal receptor and anchored in the membrane of the innate immune cells First reported in Drosophila where it was found that TLR─ ( mutant Drosophila for TLR )shows improper development during embryonic stages which is called ‘weird’ or ‘toll’ It was later on reported that the weird development in Drosophila was due to the infection of Aspergillus fumigates as these were TLR─ Around 12 different TLR are reported in human, out of which TLR 1, 2, 4 and 6 forms dimer for efficient transduction of signal[IMMUNOLOGY] July 20, 2010 2 A sample copy of Biology4You| http://aleenabioinfo.webs.com VARIOUS TLR AND THEIR LIGAND (PAMP of Ag) RECOGNITION Receptor Recognizes 1 TLR 1 Triacyl lipopeptides of Mycobacterium 2 TLR 2 Peptidoglycan 3 TLR 3 ds RNA of virus (e.g. Wound Tumour virus ) 4 TLR 4 LPS 5 TLR 5 Flagellin 6 TLR 6 Zymosan of most fungi and diacyl lipopeptides of most bacterium 7 TLR 7 Recognizes ssRNA 8 TLR 8 ssRNA 9 TLR 9 Glycoprotein and also observed to respond against HIV 10 TLR 10 Unknown 11 TLR 11 Unknown 12 TLR 12 Unknown SIGNAL TRANSDUCTION MECHANISM BY TLR[IMMUNOLOGY] July 20, 2010 3 A sample copy of Biology4You| http://aleenabioinfo.webs.com TRAF-Tumour Necrosis Factor Receptor Associated Factor TAK – Transforming Growth Factor Beta Activated kinase IKK – Inhibitor kappa-B Activating kinase NF-kB – Nuclear Factor Kappa B MAP –k –Mitogen Associated Protein kinase I-kB-Inhibitor kappa B It has been observed that NF-kB causes transcription activation of diptericin coding gene which gives defense against gram negative , hence possible upon TLR 4 signalling Nb. Most important matters are labeled red. Do not skip them during your final preparation For more materials and handouts for CSIR and other National Level Competitive Exams please visit http://aleenabioinfo.webs.com