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Effects of over-expression of TLR2 in transgenic goats on pathogen clearance and role of up-regulation of lysozyme secretion and infiltration of inflammatory cells

Shoulong Deng12, Kun Yu12, Baolu Zhang1, Yuchang Yao4, Yufeng Liu5, Haijuan He5, Hongtao Zhang6, Maosheng Cui7, Juncai Fu1, Zhengxing Lian123* and Ning Li1

Author Affiliations

1 National key Lab of Agro-biotechnology, China Agricultural University, Beijing, 100193, People’s Republic of China

2 Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, People’s Republic of China

3 National key Lab of Agro-biotechnology, Beijing, 100193, People’s Republic of China

4 College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, People’s Republic of China

5 Animal Husbandry Research Institute of HeilongjiangAcademy of Agricultural Sciences, Harbin, 150086, People’s Republic of China

6 College of Life Science and Technology, HeilongjiangBa Yi Agricultural University, Daqing, 163000, People’s Republic of China

7 Tianjin Institute of Animal Sciences, Tianjin, 300112, People’s Republic of China

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BMC Veterinary Research 2012, 8:196  doi:10.1186/1746-6148-8-196

Published: 22 October 2012



Toll-like receptor 2 (TLR2) is important to host recognition of invading gram-positive microbes. In goats, these microbes can cause serious mastitis, anthrax, tetanus, and other problems. Transgenic goats constitutively over-expressing TLR2 in many tissues serve as a suitable model for the study of the role of TLR2 over-expression in bacterial clearance.


Capra hircus TLR2 over-expression vector (p3S-LoxP-TLR2) was used to generate transgenic goats by egg microinjection. The integration efficiency was 8.57%. Real-time PCR and immunohistochemical results confirmed that the goats over-expressing the TLR2 gene (Tg) expressed more TLR2 than wild-type goats (WT). Monocyte-macrophages from the bloodstreams of transgenic goats were stimulated with synthetic bacterial lipoprotein (Pam3CSK4) and by the promotion of interleukin-6 (IL-6) and IL-10 expression in vitro. The oxidative damage was significantly reduced, and lysozyme (LZM) secretion was found to be up-regulated. Ear tissue samples from transgenic goats that had been stimulated with Pam3CSK4 via hypodermic injection showed that transgenic individuals can undergo the inflammation response very quickly.


Over-expression of TLR2 was found to decrease radical damage to host cells through low-level production of NO and MDA and to promote the clearance of invasive bacteria by up-regulating lysozyme secretion and filtration of inflammatory cells to the infected site.

Goats; TLR2; Over-expression; Pam3CSK4