Innate immunity: Toll-like receptors: practice question

A Microbiology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Microbiology · Innate immunity: Toll-like receptors

Sample item

Intestinal epithelial and dendritic cells sense the whip-like protein of a motile Salmonella and release inflammatory cytokines through MyD88 signalling. Which receptor recognises this component?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

A. TLR5

TLR5 binds bacterial flagellin, the structural protein of flagella, and signals through MyD88 to activate NF-kB. Different Toll-like receptors recognise different pathogen-associated molecular patterns.

Option by option

  • A. TLR5 (correct)

    Correct. TLR5 is the receptor for flagellin.

  • B. TLR3

    TLR3 detects double-stranded viral RNA within endosomes.

  • C. TLR9

    TLR9 detects unmethylated CpG DNA in endosomes.

  • D. TLR2

    TLR2 pairs with TLR1 or TLR6 to detect lipoproteins and lipoteichoic acid.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

More Microbiology questions

Questions about this Microbiology question

What is the answer to this Microbiology question?

The best answer is A, TLR5. TLR5 binds bacterial flagellin, the structural protein of flagella, and signals through MyD88 to activate NF-kB.

Why is "TLR3" not the answer?

TLR3 detects double-stranded viral RNA within endosomes.

Why is "TLR9" not the answer?

TLR9 detects unmethylated CpG DNA in endosomes.

Why is "TLR2" not the answer?

TLR2 pairs with TLR1 or TLR6 to detect lipoproteins and lipoteichoic acid.

What concept does this question test?

It tests Innate immunity: Toll-like receptors in Microbiology. Different Toll-like receptors recognise different pathogen-associated molecular patterns.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Innate immunity: Toll-like receptors?

Make a one-line identity card for each organism: shape and stain, defining test, toxin, disease and drug. Then use the flashcards and the other Microbiology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.