title: An Immunosuppressant Peptide from the Hard Tick Amblyomma variegatum.
abstract: Ixodid ticks are well known for spreading transmitted tick-borne pathogens while being attached to their hosts for almost 1-2 weeks to obtain blood meals. Thus, they must secrete many immunosuppressant factors to combat the hosts' immune system. In the present work, we investigated an immunosuppressant peptide of the hard tick Amblyomma variegatum. This peptide, named amregulin, is composed of 40 residues with an amino acid sequence of HLHMHGNGATQVFKPRLVLKCPNAAQLIQPGKLQRQLLLQ. A cDNA of the precursor peptide was obtained from the National Center for Biotechnology Information (NCBI, Bethesda, MD, USA). In rat splenocytes, amregulin exerts significant anti-inflammatory effects by inhibiting the secretion of inflammatory factors in vitro, such as tumor necrosis factor-alpha (TNF-α), interleukin-1 (IL-1), interleukin-8 (IL-8) and interferon-gamma (IFN-γ). In rat splenocytes, treated with amregulin, compared to lipopolysaccharide (LPS) alone, the inhibition of the above inflammatory factors was significant at all tested concentrations (2, 4 and 8 µg/mL). Amregulin shows strong free radical scavenging and antioxidant activities (5, 10 and 20 µg/mL) in vitro. Amregulin also significantly inhibits adjuvant-induced paw inflammation in mouse models in vivo. This peptide may facilitate the ticks' successful blood feeding and may lead to host immunotolerance of the tick. These findings have important implications for the understanding of tick-host interactions and the co-evolution between ticks and the viruses that they bear.
authors.affiliation: Clinical Laboratory, People's Hospital of Rizhao, 126th Taian Road, Rizhao 276826, Shandong, China. tyf6909@163.com.|College of Life Sciences, Nanjing Agricultural University, Weigang #1, Nanjing 210095, Jiangsu, China. tyf6909@163.com.
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Tian
authors.affiliation: Yunnan Clinical Research Center of Breast Cancer, The Third Affiliated Hospital of Kunming Medical College, Kunming 650032, China. chenwenlin@aliyun.com.
authors.forename: Wenlin
authors.initials: W
authors.lastname: Chen
authors.affiliation: College of Life Sciences, Nanjing Agricultural University, Weigang #1, Nanjing 210095, Jiangsu, China. mgx@njau.edu.cn.
authors.forename: Guoxiang
authors.initials: G
authors.lastname: Mo
authors.affiliation: College of Life Sciences, Nanjing Agricultural University, Weigang #1, Nanjing 210095, Jiangsu, China. frank.sledge@hotmail.com.
authors.forename: Ran
authors.initials: R
authors.lastname: Chen
authors.affiliation: College of Life Sciences, Nanjing Agricultural University, Weigang #1, Nanjing 210095, Jiangsu, China. 2015116044@njau.edu.cn.
authors.forename: Mingqian
authors.initials: M
authors.lastname: Fang
authors.affiliation: College of Life Sciences, Nanjing Agricultural University, Weigang #1, Nanjing 210095, Jiangsu, China. gyedid03@yahoo.com.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Yedid
authors.affiliation: College of Life Sciences, Nanjing Agricultural University, Weigang #1, Nanjing 210095, Jiangsu, China. yanxw@njau.edu.cn.
authors.forename: Xiuwen
authors.initials: X
authors.lastname: Yan
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D016207:Cytokines / Q000378:metabolism; D004487:Edema / Q000188:drug therapy; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D026863:Ixodidae; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D051379:Mice; D010455:Peptides / Q000494:pharmacology*; D017208:Rats, Wistar; D012469:Salivary Glands / Q000737:chemistry; D013154:Spleen / Q000166:cytology / Q000378:metabolism
chemical_list: D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D016207:Cytokines; D007166:Immunosuppressive Agents; D008070:Lipopolysaccharides; D010455:Peptides
keywords: Amblyomma variegatum; blood sucking; hard tick; immunosuppressant peptide; salivary glands