TY - JOUR
T1 - Microfibrillar-associated protein 4 (MFAP4) genes in catfish play a novel role in innate immune responses
AU - Niu, Donghong
AU - Peatman, Eric
AU - Liu, Hong
AU - Lu, Jianguo
AU - Kucuktas, Huseyin
AU - Liu, Shikai
AU - Sun, Fanyue
AU - Zhang, Hao
AU - Feng, Tingting
AU - Zhou, Zunchun
AU - Terhune, Jeffery
AU - Waldbieser, Geoff
AU - Li, Jiale
AU - Liu, Zhanjiang
N1 - Funding Information:
This project was supported in part by a grant from the USDA AFRI Animal Genome Tools and Resources Program (USDA/NRICGP award# 2009-35205-05101) and in part by USDA, ARS CRIS 6402-31000-08-00D. We would like to thank Dr. Cova Arias for her assistance in the Flavobacterium columnare challenge.
PY - 2011/5
Y1 - 2011/5
N2 - The lectin pathway of the complement system is characterized by two groups of soluble pattern recognition molecules, mannose-binding lectins (MBLs) and ficolins. These molecules recognize and bind carbohydrates in pathogens and activate complement leading to opsonization, leukocyte activation, and direct pathogen killing. While MBLs have been reported in many fish species, ficolins do not appear to be present in the teleost lineage, despite their importance in invertebrate and higher vertebrate innate immunity. A protein with a similar fibrinogen-like domain, microfibrillar-associated protein 4, MFAP4, is present in fish, albeit with no described immune function. We examined whether MFAP4 genes in fish may potentially act as pathogen receptors in the absence of ficolin. We isolated and characterized five MFAP4 genes from channel catfish. Linkage mapping and phylogenetic analysis indicated that at least three of the catfish MFAP4 genes are tightly clustered on a single chromosome, suggesting that they may have arisen through tandem duplication. Divergent, duplicated families of MFAP4 genes are also present in other teleost species. Expression analysis of the catfish MFAP4 transcripts revealed unique patterns of homeostatic expression among the genes in gill, spleen, skin, liver, and muscle. Expression of the five MFAP4 transcripts showed significant changes in expression as soon as 4. h after infection with either Edwardsiella ictaluri or Flavobacterium columnare with modulation of expression continuing up to 7 d following pathogen exposure. Several different tissues and gene-specific patterns were captured and transcript expression changes of >30-fold were observed over the course of the bacterial challenges. Our results suggest a novel role for MFAP4 in teleost immune responses.
AB - The lectin pathway of the complement system is characterized by two groups of soluble pattern recognition molecules, mannose-binding lectins (MBLs) and ficolins. These molecules recognize and bind carbohydrates in pathogens and activate complement leading to opsonization, leukocyte activation, and direct pathogen killing. While MBLs have been reported in many fish species, ficolins do not appear to be present in the teleost lineage, despite their importance in invertebrate and higher vertebrate innate immunity. A protein with a similar fibrinogen-like domain, microfibrillar-associated protein 4, MFAP4, is present in fish, albeit with no described immune function. We examined whether MFAP4 genes in fish may potentially act as pathogen receptors in the absence of ficolin. We isolated and characterized five MFAP4 genes from channel catfish. Linkage mapping and phylogenetic analysis indicated that at least three of the catfish MFAP4 genes are tightly clustered on a single chromosome, suggesting that they may have arisen through tandem duplication. Divergent, duplicated families of MFAP4 genes are also present in other teleost species. Expression analysis of the catfish MFAP4 transcripts revealed unique patterns of homeostatic expression among the genes in gill, spleen, skin, liver, and muscle. Expression of the five MFAP4 transcripts showed significant changes in expression as soon as 4. h after infection with either Edwardsiella ictaluri or Flavobacterium columnare with modulation of expression continuing up to 7 d following pathogen exposure. Several different tissues and gene-specific patterns were captured and transcript expression changes of >30-fold were observed over the course of the bacterial challenges. Our results suggest a novel role for MFAP4 in teleost immune responses.
KW - Catfish
KW - Edwardsiella ictaluri
KW - Ficolin
KW - Flavobacterium columnare
KW - Ictalurus punctatus
KW - Lectin
KW - MFAP4
KW - Microfibrillar-associated protein 4
UR - http://www.scopus.com/inward/record.url?scp=79952449758&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79952449758&partnerID=8YFLogxK
U2 - 10.1016/j.dci.2011.01.002
DO - 10.1016/j.dci.2011.01.002
M3 - Article
C2 - 21232551
AN - SCOPUS:79952449758
SN - 0145-305X
VL - 35
SP - 568
EP - 579
JO - Developmental and Comparative Immunology
JF - Developmental and Comparative Immunology
IS - 5
ER -