圆PLoS|oNE RESEARCH ARTICLE A Pre-Clinical Safety Evaluation of SBP(HBSAg Binding Protein) Adjuvant for Hepatitis B Vaccine Jingbo Wang, Caixia Su, Rui Liu, Baoxiu Liu, Inam Ullah Khan, Jun Xie*, Naishuo Zhu Laboratory of Molecular Immunology, State Key Laboratory of Genetic Engineering, Institute of Biomedical Science, School of Life Sciences, Fudan University, Shanghai, China zhu@fudan.edu.cn(NZ);xiejun@fudan.edu.cn(JX) Check for Abstract Although adjuvants are a common component of many vaccines, there are few adjuvants licensed for use in humans due to concerns about their toxic effects There is a need to develop new and safe adjuvants, because some existing vaccines have low immunogenicity OpenACCESS among certain patient groups. In this study, SBP, a hepatitis B surface antigen binding pro- tein that was discovered through screening a human liver cDNA expression library, was Citation: Wang J, Su C, Liu R, Liu B, Khan IU, Xie introduced into hepatitis B vaccine. a good laboratory practice, non-clinical safety evaluation SBP (HBsAg-Binding Protein) Adjuvant for was performed to identify the side effects of both SBP and SBP-adjuvanted hepatitis B vac- PLOS ONE 12(1): 0170313. cine. The results indicate that SBP could enhance the HBsAg-specific thus increasing the protection provided by the hepatitis B vaccine. The safety data obtained Editor: Isabelle A Chemin, Centre de Recherche en here warrant further investigation of SBP as a vaccine adjuvant Cancerologie de lyon, FRANCE Accepted: January 2, 2017 Published: January 19, 2017 Introduction Copyright: 2017 Wang et a. This is an open The infectious disease hepatitis B, which is caused by the hepatitis B virus(HBv), has troubled Creative Commons Attribution License, which people worldwide for many years. The current prophylactic HBV vaccines, which are based on permits unrestricted use, distribution, and recombinant hepatitis B surface antigen(HBsAg), have successfully decreased rates of HB reproduction in any medium, provided the original infection and transmission. However, there are more than 2 billion people who have been author and source are credited infected with HBV and are therefore at high risk for liver failure, cirrhosis, or cancer [1]. Spe- Data Availability Statement: All relevant data are cific groups of patients respond poorly or not at all to conventional HBv vaccines. Because of within the paper. the poor immunogenicity of HBsAg, new methods are needed to improve the ability of the Funding: This work was supported by the National HBV vaccine to trigger protective immunity [2, 3]. Third-generation HBV vaccines that com- Major Scientific and Technological Special Project bine small S antigen with PreSl and PreS2 antigens have been shown to induce a stronger (2012zx10002006-002-003,http://www.nmp.ov.immuneresponseinnon-andlowrespondersthancurrentHbvvaccines[4].Conventionally xis/zdy/201012/20101208 2128 htm), the used adjuvants, such as aluminum salts, allow for persistent release of the antigen, delaying ational High Technology Research and clearance and resulting in more exposure to the immune system [5]. Adjuvants can elicit effec- http:/program.mostgov.cn),theNationalNaturaltiveinnateandadaptiveimmuneresponsesthroughincreasingtheabilityofantigenstoacti cience Foundation of China(31370927 vate signaling pathways 30571650,http://www.nsfc.gov.cndandthe Although adjuvants improve vaccine formulations and lead to better and more controllable Science and Technology Innovation Action Plan of immune responses, very few adjuvants have been licensed for use in humans because of PLOS ONE DO1: 10. 1371/journal pone. 0170313 JanuaryRESEARCH ARTICLE A Pre-Clinical Safety Evaluation of SBP (HBsAg￾Binding Protein) Adjuvant for Hepatitis B Vaccine Jingbo Wang, Caixia Su, Rui Liu, Baoxiu Liu, Inam Ullah Khan, Jun Xie*, Naishuo Zhu* Laboratory of Molecular Immunology, State Key Laboratory of Genetic Engineering, Institute of Biomedical Science, School of Life Sciences, Fudan University, Shanghai, China * nzhu@fudan.edu.cn (NZ); xiejun@fudan.edu.cn (JX) Abstract Although adjuvants are a common component of many vaccines, there are few adjuvants licensed for use in humans due to concerns about their toxic effects. There is a need to develop new and safe adjuvants, because some existing vaccines have low immunogenicity among certain patient groups. In this study, SBP, a hepatitis B surface antigen binding pro￾tein that was discovered through screening a human liver cDNA expression library, was introduced into hepatitis B vaccine. A good laboratory practice, non-clinical safety evaluation was performed to identify the side effects of both SBP and SBP-adjuvanted hepatitis B vac￾cine. The results indicate that SBP could enhance the HBsAg-specific immune response, thus increasing the protection provided by the hepatitis B vaccine. The safety data obtained here warrant further investigation of SBP as a vaccine adjuvant. Introduction The infectious disease hepatitis B, which is caused by the hepatitis B virus (HBV), has troubled people worldwide for many years. The current prophylactic HBV vaccines, which are based on recombinant hepatitis B surface antigen (HBsAg), have successfully decreased rates of HBV infection and transmission. However, there are more than 2 billion people who have been infected with HBV and are therefore at high risk for liver failure, cirrhosis, or cancer [1]. Spe￾cific groups of patients respond poorly or not at all to conventional HBV vaccines. Because of the poor immunogenicity of HBsAg, new methods are needed to improve the ability of the HBV vaccine to trigger protective immunity [2, 3]. Third-generation HBV vaccines that com￾bine small S antigen with PreS1 and PreS2 antigens have been shown to induce a stronger immune response in non- and low responders than current HBV vaccines [4]. Conventionally used adjuvants, such as aluminum salts, allow for persistent release of the antigen, delaying clearance and resulting in more exposure to the immune system [5]. Adjuvants can elicit effec￾tive innate and adaptive immune responses through increasing the ability of antigens to acti￾vate signaling pathways. Although adjuvants improve vaccine formulations and lead to better and more controllable immune responses, very few adjuvants have been licensed for use in humans because of PLOS ONE | DOI:10.1371/journal.pone.0170313 January 19, 2017 1 / 11 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Wang J, Su C, Liu R, Liu B, Khan IU, Xie J, et al. (2017) A Pre-Clinical Safety Evaluation of SBP (HBsAg-Binding Protein) Adjuvant for Hepatitis B Vaccine. PLoS ONE 12(1): e0170313. doi:10.1371/journal.pone.0170313 Editor: Isabelle A Chemin, Centre de Recherche en Cancerologie de Lyon, FRANCE Received: July 27, 2016 Accepted: January 2, 2017 Published: January 19, 2017 Copyright: © 2017 Wang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper. Funding: This work was supported by the National Major Scientific and Technological Special Project (2012ZX10002006-002-003, http://www.nmp.gov. cn/zxjs/zdxy/201012/t20101208_2128.htm), the National High Technology Research and Development Program of China (2011AA02A114, http://program.most.gov.cn/), the National Natural Science Foundation of China (31370927 and 30571650, http://www.nsfc.gov.cn/) and the Science and Technology Innovation Action Plan of