Chun-Ming Lin

Food Animal Health Research Program

OARDC Wooster, OH 44691
Phone: (330)-263-3567
Fax: 330-263-3760
Email: lin.1903@osu.edu

Biographical Information

  • BS, June 2004, National Taiwan University, Taipei, Taiwan, Veterinary Medicine.
  • MS, June 2006, National Taiwan University, Taipei, Taiwan, Veterinary Pathology, Immunology and Virology.
  • PhD, June 2012, National Taiwan University, Taipei, Taiwan, Veterinary Pathology, Immunology and Virology.
  • Post-doc, 2014-Present, The Ohio State University, OARDC, Wang Laboratory.

Research Area

1. Molecular attenuation mechanisms of porcine epidemic diarrhea virus (PEDV).
Highly contagious and virulent PEDV suddenly emerged in US swine in April 2013. The high mortality rate (70-100%) among nursing pigs led to significant economic losses. Neonatal piglets generally get infected and die before they are able to have vaccine-induced immunity. Therefore, an effective vaccine should target their mothers, so the piglets can receive protective maternal antibodies by suckling the milk. To accomplish this, a live but weakened (attenuated) vaccine is required but still under development in the US Knowledge of the molecular attenuation mechanisms of PEDV is limited.
In this study, our research team investigated three methods for acquiring live PEDV strains as attenuated vaccine candidates. One strain, “mild” S-INDEL PEDV Iowa106, occurs naturally in US pig farms. It differs genetically from the original, highly virulent PEDV strains and these genetic differences result in lower virulence in pigs. However,in our laboratory, the Iowa106 can still result in severe diarrhea and death in a number of pig litters. Therefore, Iowa106 is not a safe vaccine candidate. We then continuously passaged a highly virulent PEDV PC22A strain in Vero cells. PC22A at passage level higher than 100th had accumulated enough mutations and became cell culture adapted in vitro and virulence attenuated in vivo. We also identified several hot spots on the viral genome related to viral pathogenicity. Currently, we are using reverse genetics to engineer mutated PEDV infectious clones to confirm genomic hot spots, resulting in virus attenuation in pigs.
2. PEDV serological diagnostic assays and conditions for vaccine efficiency evaluation.
Facing the emergence of PEDV in the US, specific serologic assays and optimized virus challenge doses are urgently needed for clinical diagnosis and vaccine efficiency tests. Therefore, we used several serological assays to establish the distinct antigenic features among several PEDV and other swine enteric coronavirus strains. Our results showed the N-terminal region of PEDV nucleocapsid (N) protein has epitope(s) similar to the same region of transmissible gastroenteritis virus (TGEV). Therefore, this region must be omitted when using PEDV N protein as an antigen in serological assays. In addition, we also showed antigenic variations between classic and emerging PEDV strains. We discovered that100 to 1000 plaque formation units of PEDV are the optimized dose of viral inoculum for testing PEDV vaccines. We also characterized the histopathological lesions of highly virulent PEDV infection in intestinal tracts and established stable animal models in our laboratory.

Lab

Selected publications

  • Hou Y, Lin CM, Yokoyama M, Yount BL, Marthaler D, Douglas AL, Ghimire S, Qin Y, Baric RS, Saif LJ*, and Wang Q*. Deletion of a 197 amino acid-region in the N-terminal domain of spike protein attenuates porcine epidemic diarrhea virus. J Virol. 91 (14).
  • Lin CM, Hou Y, Marthaler D, Gao X, Liu X, Zhang L, Saif LJ, Wang Q. Attenuation of an Original US Porcine Epidemic Virus Strain PC22A via Serial Cell Culture Passage. Veterinary Microbiology. 2017; 201(62-71):
  • Beall A, Yount B, Lin CM, Hou Y, Wang Q, Saif L, Baric R. Characterization of a Pathogenic Full-Length cDNA Clone and Transmission Model for Porcine Epidemic Diarrhea Virus Strain PC22A. mBio. 2016; 7(1):e01451-15.
  • Lin CM, Saif LJ, Marthaler D, Wang Q. Evolution, antigenicity and pathogenicity of global porcine epidemic diarrhea virus strains. Virus research. 2016. Jun 8. pii: S0168-1702(16)30225-8.
  • Lin CM, Gao X, Oka T, Vlasova AN, Esseili MA, Wang Q, Saif LJ. Antigenic relationships among porcine epidemic diarrhea virus and transmissible gastroenteritis virus strains. Journal of virology. 2015; 89(6):3332-42.
  • Liu X*, Lin CM*, Annamalai T, Gao X, Lu Z, Esseili MA, Jung K, El-Tholoth M, Saif LJ, Wang Q. Determination of the infectious titer and virulence of an original US porcine epidemic diarrhea virus PC22A strain. Veterinary research. 2015; 46:109.
  • Lin CM, Annamalai T, Liu X, Gao X, Lu Z, El-Tholoth M, Hu H, Saif LJ, Wang Q. Experimental infection of a US spike-insertion deletion porcine epidemic diarrhea virus in conventional nursing piglets and cross-protection to the original US PEDV infection. Veterinary research. 2015; 46:134
  • Oka T, Saif LJ, Marthaler D, Esseili MA, Meulia T, Lin CM, Vlasova AN, Jung K, Zhang Y, Wang Q. Cell culture isolation and sequence analysis of genetically diverse US porcine epidemic diarrhea virus strains including a novel strain with a large deletion in the spike gene. Veterinary microbiology. 2014; 173(3-4):258-69.