My laboratory is interested in innate immune responses modulated by plasma proteins and expression of antimicrobial peptides regulated by signal transduction pathways in a model insect, the tobacco hornworm Manduca sexta. Insects lack an immunoglobulin-mediated acquired immunity, but they have developed an effective and sophisticated immune system similar to the innate immune system of vertebrates. In the innate immune system, recognition of pathogens and differentiation of nonself are critical to the host animals to trigger effective immune responses. Initial recognition of pathogens in innate immunity is mediated by pattern recognition receptors (PRRs) that can recognize structural molecular patterns, termed pathogen-associated molecular patterns (PAMPs), present on the surface of many microbes and pathogens but not on the host cells. Our research focuses on:
- C-type lectins as key PRRs in innate immune responses. C-type lectins are calcium-dependent carbohydrate-binding proteins. We have discovered a group of at least four C-type lectins, named immulectins, in M. sexta. These immulectins can enhance hemocyte (blood cell) phagocytosis, encapsulation and melanization. Our current work is to investigate how immulectins recognize and bind to microbial surface molecules such as bacterial lipopolysaccharide (LPS) and lipoteichoic acid (LTA), to trigger innate immune responses.
- Modulation of phenoloxidase (PO) activation. Melanotic encapsulation is an effective immune response to pathogens, particularly to large pathogens like nematodes and parasitoid eggs. Melanization requires activation of PO, a process that involves a cascade of serine proteinases. However, PO activation can also be modulated by non-enzymatic proteins. For example, we found that serine proteinase homologs (SPHs) are essential co-factors in PO activation by proteinases. We also found that a small cationic protein, lysozymes, and immulectins can either positively or negatively regulate PO activity. Currently, we are investigating how these proteins can modulate PO activation.
- Regulation of antimicrobial peptide genes. Insects can synthesize a variety of antimicrobial peptides (AMPs) upon microbial infections. The majority of AMPs is present in all insects, while some are species-specific. For example, Gloverin and Moricin are found only in Lepidoptera but not in Diptera (Drosophila and mosquitoes). Expression of AMPs is regulated by signal transduction pathways, such as the Toll and IMD (immune deficiency) pathways in Drosophila. Our research is to investigate how AMPs, particularly Gloverin and Moricin, are regulated in M. sexta hemocytes, and to identify additional signaling pathways that may activate AMPs by LPS.
Wu J, Liu XH, Huang R, Wu HS, Guo QY, Yi CY, Yu XQ, Yang X. Age differences in associations of serum alkaline phosphatase and mortality among peritoneal dialysis patients. (2019). Chinese medical journal, Journal Article.
Cheng ES, Yu XQ. Re: The relationship between patient and tumor characteristics, patterns of breast cancer care, and 5-year survival among elderly women with incident breast cancer. Breast Cancer Res Treat. Sep 2018;171(2):477-488. (2019). Breast cancer research and treatment, Letter.
Zhang LL, Hu XH, Wu SQ, Batool K, Chowdhury M, Lin Y, Zhang J, Gill SS, Guan X, Yu XQ. Aedes aegypti Galectin Competes with Cry11Aa for Binding to ALP1 To Modulate Cry Toxicity. (2018). Journal of agricultural and food chemistry, Journal Article.
Feletto E, Yu XQ, Lew JB, St John DJB, Jenkins MA, Macrae FA, Mahady SE, Canfell K. Trends in Colon and Rectal Cancer Incidence in Australia from 1982 to 2014: Analysis of Data on Over 375,000 Cases. (2019). Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, 28 (1), 83-90. Journal Article.
Xiao YP, Zhang J, Liu YH, Zhang JH, Yu QY, Huang Z, Yu XQ. Low molecular weight PEI-based fluorinated polymers for efficient gene delivery. (2019). European journal of medicinal chemistry, 162 602-611. Journal Article.
Bi J, Zheng Y, Wang RF, Ai H, Haynes PR, Brownlie JC, Yu XQ, Wang YF. Wolbachia infection may improve learning and memory capacity of Drosophila by altering host gene expression through microRNA. (2018). Insect biochemistry and molecular biology, Journal Article.
Zhao TT, Cui L, Li JJ, Liang QL, Wu PJ, Yu XQ, Zhang ZH, Hua XG. Optimal expression and purification of sapelovirus A structural protein VP1, and its immunogenicity in mice. (2018). Polish journal of veterinary sciences, 21 (3), 573-579. Journal Article.
Zhou Q, Li K, Liu YH, Li LL, Yu KK, Zhang H, Yu XQ. Fluorescent Wittig reagent as a novel ratiometric probe for the quantification of 5-formyluracil and its application in cell imaging. (2018). Chemical communications (Cambridge, England), 54 (97), 13722-13725. Journal Article.
Luo Q, Yu XQ, Wade S, Caruana M, Pesola F, Canfell K, O'Connell DL. Lung cancer mortality in Australia: Projected outcomes to 2040. (2018). Lung cancer (Amsterdam, Netherlands), 125 68-76. Journal Article.
Zhang J, Yang W, Xu J, Yang W, Li Q, Zhong Y, Cao Y, Yu XQ, Deng X. Regulation of antimicrobial peptide genes via insulin-like signaling pathway in the silkworm Bombyx mori. (2018). Insect biochemistry and molecular biology, 103 12-21. Journal Article.
Li M, Yu XQ. Genetic Determinants of IgA Nephropathy: Eastern Perspective. (2018). Seminars in nephrology, 38 (5), 455-460. Journal Article, Review.
Ali SO, Yu XQ, Robbie GJ, Wu Y, Shoemaker K, Yu L, DiGiandomenico A, Keller AE, Anude C, Hernandez-Illas M, Bellamy T, Falloon J, Dubovsky F, Jafri HS. Phase 1 study of MEDI3902, an investigational anti-Pseudomonas aeruginosa PcrV and Psl bispecific human monoclonal antibody, in healthy adults. (2018). Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases, Journal Article.
Zhang RN, Ren FF, Zhou CB, Xu JF, Yi HY, Ye MQ, Deng XJ, Cao Y, Yu XQ, Yang WY. An ML protein from the silkworm Bombyx mori may function as a key accessory protein for lipopolysaccharide signaling. (2018). Developmental and comparative immunology, 88 94-103. Journal Article.
He Y, Yu XQ, Luo Q, Xu X, Wang Y, Li S, Shan B. Patterns of care of nonsmall cell lung cancer patients in China and implications for survival. (2018). Journal of cancer research and therapeutics, 14 (Supplement), S410-S415. Journal Article.
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