International Journal of Microbiology and Immunology Research Vol. 2(4), pp. 048-053, June 2014 ISSN 2327-7769 ©2014 Academe Research Journals

Review

Role of NLR proteins in immunity

Hina Afroz¹*, Zahid Hussain¹, Maria Azam¹, Maqsood Arif¹ and Rehan Rafique²

¹Institute of Industrial Biotechnology, G. C. University, Lahore, Pakistan.

²Veterinary Research Institute, Lahore Cantt., Pakistan.

*Corresponding author. E-mail: anih_zorfa@hotmail.com.

Accepted 19 May, 2014

Abstract

The first line of defense in immune system is the innate immunity. Nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) proteins are important for the innate immune response and they play a significant role in microbial sensing. These proteins are consisted of protein domains like Nucleotide Binding Domain (NBD), Nucleotide-binding oligomerization domain (NOD) centrally and a protein interaction domain; furthermore, Leucine Rich Repeats (LRRs) are present at the C terminal. NLR proteins are located in the cytoplasm and are able to recognize microbial antigens. Inflammatory responses occur as a result of activation of NLR protein via caspase-1 activation. Mitogen-Activated Protein Kinase (MAPK) and Nuclear Factor-kappa B (NF-κB) activation are also involved in the inflammatory reactions produced by NLR proteins. This review will cover mainly NOD like Receptor Protein 1 (NLRP1), NOD like Receptor Protein 3 (NLRP3), NOD like Receptor Card domain 4 (NLRC4) and especially their functions against pathogen attacks.

Key words: LRRs, PAMP, DAMP, inflammasomes, AIMS2.NALP1, NALP3, NALC4.