Development of neutralizing monoclonal antibodies against VP4 of rotavirus CC0812-1

The G10P[15] rotavirus CC0812-1 isolated from a diarrheal woman in Wuhan, China, in 2008 is phylogenetically close to the Lanzhou lamb rotavirus (LLR) of a monovalent human rotavirus vaccine produced by the Lanzhou Institute of Biological Products, China, and rotavirus Lamb-NT. This rotavirus can be used as the backbone of the attenuated rotavirus reassortant as a rotavirus vaccine candidate. In this study, rotavirus CC0812-1 was purified from the culture supernatant of CC0812-1-infected MA104 cells and used as antigen to immunize BALB/c mice. Four hybridoma clones were developed secreting antibodies that reacted with CC0812-1, designated as 1B1, 1B8, 1F11, and 1G10, respectively. Western blot analysis indicated that the four monoclonal antibodies (MAbs) were all specific for VP4 of rotavirus CC0812-1. Isotyping revealed that MAbs 1B1, 1B8, and 1G10 belonged to the IgM class, while MAb 1F11 belonged to the IgG1 subclass. A neutralization test demonstrated that the four MAbs all had the capacity to neutralize rotavirus CC0812-1. The neutralizing titers of the BALB/c mice ascites were 1:2048, 1:1024, 1:512, and 1:512 for MAbs 1B1, 1B8, 1F11, and 1G10, respectively.