近年來蝦類養殖業蓬勃發展，卻仍持續遭受疾病滋擾，造成巨大的經濟損失。因此許多研究集中在蝦類先天性免疫上，而模式識別受體（PRRs）和病原體相關分子模式（PAMPs）間的相互作用在免疫識別過程中扮演著重要的角色。在多種已鑑定出的PRRs中，C型凝集素（C-type lectin）最受討論。其藉由與病原體表面碳水化合物的結合，展現出抗細菌和病毒的潛力。本研究從實驗室白蝦轉錄體資料庫中鑑定出一新型C型凝集素LvCTL 4.2。LvCTL 4.2在N端及C端分別具有一個訊號肽和一個突變甘露糖結合模體（Glu-Pro-Ala；EPA）的碳水化合物識別域（CRD），推測其為具有甘露糖結合特性的分泌型C型凝集素。在確認LvCTL 4.2高度表現於蝦胃中，且其基因表現在WSSV早期感染階段（12 hpi）有上調現象後，透過體內dsRNA基因靜默平台，發現LvCTL 4.2的靜默化抑制了WSSV的複製。ELISA結合測定分析則顯示rLvCTL 4.2對細菌和WSSV病毒顆粒具有很強的結合特異性。抗菌活性測定也顯示rLvCTL 4.2會抑制Vibrio parahaemolyticus的生長。而rLvCTL 4.2與WSSV的結合促進了WSSV的複製和蝦隻的死亡率。總結本篇研究，LvCTL 4.2作為PRR，會抑制AHPND致病菌的生長，但促進WSSV的發病機制。

White Spot Disease (WSD) and acute hepatopancreatic necrosis disease (AHPND) are the main diseases threatening global shrimp aquaculture. Innate immune responses in white shrimp have been studied, including identification of numerous pattern recognition receptors (PRRs). Among them, various C-type lectins have been implicated as conferring protection against bacteria and viruses. Here, we identified a novel C-type lectin LvCTL 4.2 from our in-house transcriptomic database. We confirmed LvCTL 4.2 mRNA was highly expressed in shrimp stomach and upregulated in the early stage (12 hpi) of WSSV infection. Furthermore, in vivo dsRNA knockdown of LvCTL 4.2 suppressed WSSV replication and in an ELISA binding assay, LvCTL 4.2 had high specificity against bacteria and the WSSV virion. Based on an antimicrobial activity assay, LvCTL 4.2 had differential effects on the growth of gram-positive and gram-negative bacteria. Finally, we validated that binding of rLvCTL 4.2 against WSSV enhanced WSSV replication and hastened shrimp mortality. In conclusion, a novel C-type lectin LvCTL 4.2 acted as a PRR and inhibited AHPND-causing bacteria but promoted WSSV pathogenesis.

何舒莛，白點症病毒於基因體複製時期活化麩醯胺酸代謝作用之氧化還原路徑，國立成功大學生物科技與產業科學系碩士論文，2018。

曾怡婷，探討蝦類Ras及其下游路徑在感染白點症病毒後代謝路徑轉移過程中所扮演之角色，國立成功大學生物科技與產業科學系碩士論文，2018。

董騰駿，探討蝦隻感染急性肝胰腺壞死病之蝦胃代謝變化反應，國立成功大學生物科技與產業科學系碩士論文，2019。

Akira, S., Uematsu, S. and Takeuchi, O. Pathogen recognition and innate immunity. Cell 124, 783-801, 2006.

Apitanyasai, K., Chang, C. C., Ng, T. H., Ng, Y. S., Liou, J. H., Lo, C. F., Lin, S. S. and Wang, H. C. Penaeus vannamei serine proteinase inhibitor 7 (LvSerpin7) acts as an immune brake by regulating the proPO system in AHPND-affected shrimp. Developmental and Comparative Immunology 106, 103600, 2020.

Bianchi, G. and Skjoldal, H. R. The ecosystem approach to fisheries management in the USA. The Ecosystem Approach to Fisheries. Centre for Agriculture and Biosciences International, England, 301-308, 2008.

Chen, R. Y., Shen, K. L., Chen, Z., Fan, W. W., Xie, X. L., Meng, C., Chang, X. J., Zheng, L. B., Jeswin, J., Li, C. H., Wang, K. J. and Liu, H. P. White spot syndrome virus entry is dependent on multiple endocytic routes and strongly facilitated by Cq-GABARAP in a CME-dependent manner. Scientific Reports 6, 1-17, 2016.

Chou, H. Y., Huang, C. Y., Wang, C. H., Chiang, H. C. and Lo, C. F. Pathogenicity of a baculovirus infection causing white spot syndrome in cultured penaeid shrimp in Taiwan. Diseases of Aquatic Organisms 3, 165-173, 1995.

Dan, X., Liu, W. and Ng, T. B. Development and applications of lectins as biological tools in biomedical research. Medicinal Research Reviews 36, 221-247, 2016.

Dastidar, P. G., Mallik, A. and Mandal, N. Contribution of shrimp disease research to the development of the shrimp aquaculture industry: an analysis of the research and innovation structure across the countries. Scientometrics 97, 659-674, 2013.

Drickamer, K. Engineering galactose-binding activity into a C-type mannose-binding protein. Nature 360, 183-186, 1992.

Drickamer, K. Evolution of Ca2+-dependent animal lectins. Progress in Nucleic Acid Research and Molecular Biology 45, 207-232, 1993.

Du, X., Wang, G., Su, Y., Zhang, M. and Hu, Y. Black rockfish C-type lectin, SsCTL4: a pattern recognition receptor that promotes bactericidal activity and virus escape from host immune defense. Fish and Shellfish Immunology 79, 340-350, 2018.

Geijtenbeek, T. B. and Gringhuis, S. I. C-type lectin receptors in the control of T helper cell differentiation. Nature Reviews Immunology 16, 433-448, 2016.

Han, J. E., Tang, K. F., Pantoja, C. R., White, B. L. and Lightner, D. V. qPCR assay for detecting and quantifying a virulence plasmid in acute hepatopancreatic necrosis disease (AHPND) due to pathogenic Vibrio parahaemolyticus. Aquaculture 442, 12-15, 2015.

Huang, Y., Shi, Y., Hu, S., Wu, T. and Zhao, Z. Characterization and Functional Analysis of Two Transmembrane C-Type Lectins in Obscure Puffer (Takifugu obscurus). Frontiers in Immunology 11, 436, 2020.

Kerrigan, A. M. and Brown, G. D. C-type lectins and phagocytosis. Immunobiology 214, 562-575, 2009.

Kumar, R., Ng, T. H., Chang, C. C., Tung, T. C., Lin, S. S., Lo, C. F. and Wang, H. C. Bile acid and bile acid transporters are involved in the pathogenesis of acute hepatopancreatic necrosis disease in white shrimp Litopenaeus vannamei. Cellular Microbiology 22, 13127, 2020.

Lai, H. C., Ng, T. H., Ando, M., Lee, C. T., Chen, I. T., Chuang, J. C., Mavichak, R., Chang, S. H., Yeh, M. D., Chiang, Y. A., Takeyama, H. O., Lo, C. F., Aoki, T. and Wang, H. C. Pathogenesis of acute hepatopancreatic necrosis disease (AHPND) in shrimp. Fish and Shellfish Immunology 47, 1006-1014, 2015.

Lee, C. T., Chen, I. T., Yang, Y. T., Ko, T. P., Huang, Y. T., Huang, J. Y., Huang, M. F., Lin, S. J., Chen, C. Y., Lin, S. S., Lightner, D. V., Wang, H. C., Wang, A. H., Wang, H. C., Hor, L. I. and Lo, C. F. The opportunistic marine pathogen Vibrio parahaemolyticus becomes virulent by acquiring a plasmid that expresses a deadly toxin. Proceedings of the National Academy of Sciences of the United States of America 112, 10798-10803, 2015.

Leu, J. H., Tsai, J.M., Wang, H. C., Wang, A. H., Wang, C. H., Kou, G. H. and Lo, C.F. The unique stacked rings n the nucleocapsid of the shite spot syndrome virus virion are formed by the major structural protein VP664, the largest viral structural protein ever found. Journal of Virology 79, 140-149, 2005.

Leu, J. H., Chang, C. C., Wu, J. L., Hsu, C. W., Hirono, I., Aoki, T., Juan, H. F., Lo, C. F., Kou, G. H. and Huang, H. C. Comparative analysis of differentially expressed genes in normal and white spot syndrome virus infected Penaeus monodon. BioMed Central Genomics 8, 120, 2007.

Leu, J. H., Kuo, Y. C., Kou, G. H. and Lo, C. F. Molecular cloning and characterization of an inhibitor of apoptosis protein (IAP) from the tiger shrimp, Penaeus monodon. Developmental and Comparative Immunology 32, 121-133, 2008.

Leu, J. H., Yang, F., Zhang, X., Xu, X., Kou, G. H. and Lo, C. F. Whispovirus. In Lesser Known Large dsDNA Viruses. Springer, Berlin, 197-227, 2009.

Li, M., Li, C., Ma, C., Li, H., Zuo, H., Weng, S., Chen, X., Zeng, D., He, J. and Xu, X. Identification of a C-type lectin with antiviral and antibacterial activity from pacific white shrimp Litopenaeus vannamei. Developmental and Comparative Immunology 46, 231-240, 2014.

Li, H., Chen, Y., Li, M., Wang, S., Zuo, H., Xu, X., Weng, S., He, J. and Li, C. A C-type lectin (LvCTL4) from Litopenaeus vannamei is a downstream molecule of the NF-κB signaling pathway and participates in antibacterial immune response. Fish and Shellfish Immunology 43, 257-263, 2015.

Lin, Y. R., Hung, H. C., Leu, J. H., Wang, H. C., Kou, G. H., and Lo, C. F. The role of aldehyde dehydrogenase and hsp70 in suppression of white spot syndrome virus replication at high temperature. Journal of Virology 85, 3517-3525, 2011.

Liu, W. J., Chang, Y. S., Wang, A. H. J., Kou, G. H. and Lo, C. F. White spot syndrome virus annexes a shrimp STAT to enhance expression of the immediate-early gene ie1. Journal of Virology 81, 1461-1471, 2007.

Luo, M., Yang, L., Wang, Z. A., Zuo, H., Weng, S., He, J. and Xu, X. A novel C-type lectin with microbiostatic and immune regulatory functions from Litopenaeus vannamei. Fish and Shellfish Immunology 93, 361-368, 2019.

Mu, L., Yin, X., Xiao, Y., Bian, X., Yang, Y., Wu, L. and Ye, J. A C-type lectin (CL11X1-like) from Nile tilapia (Oreochromis niloticus) is involved in host defense against bacterial infection. Developmental and Comparative Immunology 84, 230-240, 2018.

Nakamoto, M., Takeuchi, Y., Akita, K., Kumagai, R., Suzuki, J., Koyama, T., Noda, T., Yoshida, K., Ozaki, A., Araki, K. and Sakamoto, T. A novel C-type lectin gene is a strong candidate gene for Benedenia disease resistance in Japanese yellowtail, Seriola quinqueradiata. Developmental and Comparative Immunology 76, 361-369, 2017.

Ng, T. H., Chiang, Y. A., Yeh, Y. C. and Wang, H. C. Review of Dscam-mediated immunity in shrimp and other arthropods. Developmental and Comparative Immunology 46, 129-138, 2014.

Ng, T. H., Lu, C. W., Lin, S. S., Chang, C. C., Tran, L. H., Chang, W. C., Lo, C.F. and Wang, H. C. The Rho signalling pathway mediates the pathogenicity of AHPND‐causing V. parahaemolyticus in shrimp. Cellular Microbiology 20, e12849, 2018.

Ng, T. H., Kumar, R., Apitanyasai, K., He, S. T., Chiu, S. P. and Wang, H. C. Selective expression of a “correct cloud” of Dscam in crayfish survivors after second exposure to the same pathogen. Fish and Shellfish Immunology 92, 430-437, 2019.

Petesch, T. Impacts of disease in shrimp aquaculture on U.S. capture fishery prices. Master thesis. Retrieved from Duke University of Nicholas School of the Environment. 2017.

Rahman, M. M., Escobedo-Bonilla, C. M., Corteel, M., Dantas-Lima, J. J., Wille, M., Sanz, V. A., Pensaert, M. B., Sorgeloos, P., and Nauwynck, H. J. Effect of high water temperature (33˚C) on the clinical and virological outcome of experimental infections with white spot syndrome virus (WSSV) in specific pathogen-free (SPF) Litopenaeus vannamei. Aquaculture 261, 842-849, 2006.

Rahman, M. M., Corteel, M., Wille, M., Alday-Sanz, V., Pensaert, M. B., Sorgeloos, P., and Nauwynck, H. J. The effect of raising water temperature to 33 ˚C in Penaeus vannamei juveniles at different stages of infection with white spot syndrome virus (WSSV). Aquaculture 272, 240-245, 2007.

Remany, M. C., Daly, C., Nagaraj, S., Panda, A. K., Jaideep, K., and Samraj, Y. C. T. Evidence for the presence of white spot syndrome virus (WSSV) and monodon baculovirus (MBV) in wild Penaeus monodon (Fabricius) broodstock, in the southeast coast of India. Journal of Fish Diseases 35, 793-798, 2012.

Rodríguez, J., Bayot, B., Amano, Y., Panchana, F., De Blas, I., Alday, V., and Calderón, J. White spot syndrome virus infection in cultured Penaeus vannamei (Boone) in Ecuador with emphasis on histopathology and ultrastructure. Journal of Fish Diseases 26, 439-450, 2003.

Sánchez-Paz, A. White spot syndrome virus: an overview on an emergent concern. Veterinary Research 41, 43, 2010.

Sancho, D. and Reis e Sousa, C. Signaling by myeloid C-type lectin receptors in immunity and homeostasis. Annual Review of Immunology 30, 491-529, 2012.

Sumner, J. B. and Howell, S. F. Identification of hemagglutinin of jack bean with concanavalin A. Journal of Bacteriology 32, 227, 1936.

Tran, L., Nunan, L., Redman, R. M., Mohney, L. L., Pantoja, C. R., Fitzsimmons, K. and Lightner, D. V. Determination of the infectious nature of the agent of acute hepatopancreatic necrosis syndrome affecting penaeid shrimp. Diseases of Aquatic Organisms 105, 45-55, 2013.

Tsai, J. M., Wang, H. C., Leu, J. H., Wang, A. H. J., Zhuang, Y., Walker, P. J., Kou, G. H. and Lo, C. F. Identification of the nucleocapsid, tegument, and envelope proteins of the shrimp white spot syndrome virus virion. Journal of Virology 80, 3021-3029, 2006.

van Hulten, M. C., Witteveldt, J., Peters, S., Kloosterboer, N., Tarchini, R., Fiers, M., Sandbrink, H., Lankhorst, R. K. and Vlak, J. M. The white spot syndrome virus DNA genome sequence. Virology 286, 7-22, 2001.

Vidal, O. M., Granja, C. B., Aranguren, F., Brock, J. A., and Salazar, M. A profound effect of hyperthermia on survival of Litopenaeus vannamei juveniles infected with white spot syndrome virus. Journal of the World Aquaculture Society 32, 364-372, 2001.

Wang, K. H. C., Tseng, C. W., Lin, H. Y., Chen, I. T., Chen, Y. H., Chen, Y. M., Chen, T. Y. and Yang, H. L. RNAi knock-down of the Litopenaeus vannamei Toll gene (LvToll) significantly increases mortality and reduces bacterial clearance after challenge with Vibrio harveyi. Developmental and Comparative Immunology 34, 49-58, 2010a.

Wang, K. H. C., Kondo, H., Hirono, I. and Aoki, T. The Marsupenaeus japonicus voltage-dependent anion channel (MjVDAC) protein is involved in white spot syndrome virus (WSSV) pathogenesis. Fish and Shellfish Immunology 29, 94-103, 2010b.

Wang, L., Zhang, J., Kong, X., Zhao, X., Pei, C. and Li, L. A C-type lectin, Nattectin-like protein (CaNTC) in Qihe crucian carp Carassius auratus: Binding ability with LPS, PGN and various bacteria, and agglutinating activity against bacteria. Fish and Shellfish Immunology 67, 382-392, 2017.

Wang, X. W. and Wang, J. X. Pattern recognition receptors acting in innate immune system of shrimp against pathogen infections. Fish and Shellfish Immunology 34, 981-989, 2013a.

Wang, X. W. and Wang, J. X. Diversity and multiple functions of lectins in shrimp immunity. Developmental and Comparative Immunology 39, 27-38, 2013b.

Wang, X. W., Zhao, X. F., Wang, J. X. C-type lectin binds to β-integrin to promote hemocytic phagocytosis in an invertebrate. Journal of Biological Chemistry 289, 2405-2414, 2014.

Wei, X., Liu, X., Yang, J., Fang, J., Qiao, H., Zhang, Y. and Yang, J. Two C-type lectins from shrimp Litopenaeus vannamei that might be involved in immune response against bacteria and virus. Fish and Shellfish Immunology 32, 132-140, 2012.

Weis, W. I., Drickamer, K. and Hendrickson, W. A. Structure of a C-type mannose-binding protein complexed with an oligosaccharide. Nature 360, 127-134, 1992.

Wu, X., Xiong, H., Wang, Y., and Du, H. Immunomodulatory effects of hyperthermia on resisting WSSV infection in P rocambarus clarkii. Journal of Fish Diseases 38, 567-574, 2015.

Yang, Y. T., Chen, I. T., Lee, C. T., Chen, C. Y., Lin, S. S., Hor, L. I., Tseng, T. C., Huang, Y. T., Sritunyalucksana, K., Thitamadee, S., Wang, H. C. and Lo, C. F. Draft genome sequences of four strains of Vibrio parahaemolyticus, three of which cause early mortality syndrome/acute hepatopancreatic necrosis disease in shrimp in China and Thailand. Genome Announcements 2, 816, 2014.

Yuan, K., Yuan, F. H., He, H. H., Bi, H. T., Weng, S. P., He, J. G., and Chen, Y. H. Heat shock 70 kDa protein cognate 5 involved in WSSV toleration of Litopenaeus vannamei. Developmental and Comparative Immunology 72, 9-20, 2017.

Zelensky, A. N. and Gready, J. E. The C‐type lectin‐like domain superfamily. The Federation of European Biochemical Societies Journal 272, 6179-6217, 2005.

Zhao, Z. Y., Yin, Z. X., Xu, X. P., Weng, S. P., Rao, X. Y., Dai, Z. X., Luo, Y. W., Yang, G., Li, Z. S., Guan, H. J., Li, S. D., Chan, S. M., Yu, X. Q. and He, J. G. A novel C-type lectin from the shrimp Litopenaeus vannamei possesses anti-white spot syndrome virus activity. Journal of Virology 83, 347-356, 2009.