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.
Zhang YF, Xu JW, Yang Y, Huang X, Yu XQ. The association between body lead levels and childhood rickets: A meta-analysis based on Chinese cohort. (2019). Medicine, 98 (8), e14680. Journal Article, Meta-Analysis.
He X, Chen P, Zhang J, Luo TY, Wang HJ, Liu YH, Yu XQ. Cationic polymer-derived carbon dots for enhanced gene delivery and cell imaging. (2019). Biomaterials science, Journal Article.
Deng J, Yu XQ, Wang PH. Inflammasome activation and Th17 responses. (2019). Molecular immunology, 107 142-164. Journal Article.
Chowdhury M, Zhang J, Xu XX, He Z, Lu Y, Liu XS, Wang YF, Yu XQ. An in vitro study of NF-κB factors cooperatively in regulation of Drosophila melanogaster antimicrobial peptide genes. (2019). Developmental and comparative immunology, 95 50-58. Journal Article.
Wen Y, He Z, Xu T, Jiao Y, Liu X, Wang YF, Yu XQ. Ingestion of killed bacteria activates antimicrobial peptide genes in Drosophila melanogaster and protects flies from septic infection. (2019). Developmental and comparative immunology, 95 10-18. Journal Article.
Xing X, Jia JQ, Zhang JF, Zhou ZW, Li J, Wang N, Yu XQ. CALB Immobilized onto Magnetic Nanoparticles for Efficient Kinetic Resolution of Racemic Secondary Alcohols: Long-Term Stability and Reusability. (2019). Molecules (Basel, Switzerland), 24 (3), Journal Article.
Wu SY, Peng F, Ding T, Tan HY, Wu Q, Yu XQ, Pan ZP, Xie HL, Xia H, Fei BM, Liu KD, Yuan ZF, Tan CR, Jiang L, Zhang SH, Yi Q, Wu WH, Luo LL, Shen CT, Zhang JF, Huang ZJ, Xia SW. [Incidence of neonatal asphyxia and contributing factors for the develpment of severe asphyxia in Hubei Enshi Tujia and Miao Autonomous Prefecture: a multicenter study]. (2019). Zhongguo dang dai er ke za zhi = Chinese journal of contemporary pediatrics, 21 (1), 6-10. Journal Article.
Shi L, Li K, Li LL, Chen SY, Li MY, Zhou Q, Wang N, Yu XQ. Novel easily available purine-based AIEgens with colour tunability and applications in lipid droplet imaging. (2018). Chemical science, 9 (48), 8969-8974. Journal Article.
Xing XS, Fu ZH, Zhang NN, Yu XQ, Wang MS, Guo GC. High proton conduction in an excellent water-stable gadolinium metal-organic framework. (2019). Chemical communications (Cambridge, England), 55 (9), 1241-1244. Journal Article.
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, 132 (2), 232-236. 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.
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