Immunogenicities of Env glycoproteins from circulating HIV-1 isolates in China focusing on the strategy of ＂DNA prime plus protein boost＂  

作　　者：WANG Zheng WANG Shi-xia LIU Si-yang BAO Zuo-yi ZHUANG Dao-min LI Lin ZHANG Chun-hua ZHANG Lu LI Jing-yun LU Shan 

机构地区：[1]Department of HIV/AIDS Research, State Key Laboratory of Pathogen and Biosecufity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing 100071, China [2]China-US Vaccine Research Center, First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu 210029, China [3]Jiangsu Key Laboratory in Infectious Diseases, Nanjing, Jiangsu 210029, China [4]Laboratory of Nucleic Acid Vaccine, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA

出　　处：《Chinese Medical Journal》2009年第19期2339-2345,共7页中华医学杂志（英文版）

基　　金：This work was supported by the grants from the China 973 Project （No. 2006CB504206） and the Natural Science Foundation of China （No. 30700706）. In addition, this work was supported by a funding from Jiangsu Provincial Key Infectious Diseases Laboratory.

摘　　要：Background The adenovirus-based HIV-1 vaccine developed by Merck Company suffered from an unexpected failure in September 2007. This generated a big shift in the strategy of HIV vaccine development with renewed focus on the induction of neutralizing antibodies. A major challenge in developing an HIV-1 vaccine is to identify immunogens and adopt delivery methods that can elicit broadly neutralizing antibodies against primary isolates of different genetic subtypes. Methods Most circulating HIV-1 isolates in China are composed of clades Thai-B, CRF_BC and CRF01_AE. In order to construct DNA vaccines against these 3 HIV-1 subtypes, DNA vaccines carrying the gp120 regions from HIV-1 isolates of GX48（AE）, GX79（AE）, NX22（BC）, GS22（BC）, HN24（Thai-B） were constructed. Expression of gp120 from these DNA vaccines was detected by Western blotting in transiently transfected 293T cells. Pilot immunizations of New Zealand white rabbits were performed using the strategy of ＂DNA prime plus protein boost＂ and the neutralizing antibody response was detected in a Tzm-bl cell based assay against different HIV-1 strains. Results Response of gp120-specific antibody was relatively low after DNA primes （mean titer=10^4.72）; however, the titer of gp120-specific antibody went up with 2 protein boosts （mean titer=10^6.81）. Above all, neutralizing antibody （Nab） titers induced by this combined approach were much better than those elicited by DNA or protein used alone （P 〈0.01）. Neutralizing activities of immunized rabbit sera against several pseudoviruses and laboratorial strains were evaluated, most rabbit sera primed with monovalent vaccine were capable of neutralizing only 1 of 5 viruses, however, sera primed with the polyvalent DNA vaccines were able to neutralize at least 2 of 5 viruses. Conclusion Polyvalent DNA prime plus protein boost is an effective immunization strategy to broaden the neutralization breadth and further research should be performed on the basis of this pilot study.Background The adenovirus-based HIV-1 vaccine developed by Merck Company suffered from an unexpected failure in September 2007. This generated a big shift in the strategy of HIV vaccine development with renewed focus on the induction of neutralizing antibodies. A major challenge in developing an HIV-1 vaccine is to identify immunogens and adopt delivery methods that can elicit broadly neutralizing antibodies against primary isolates of different genetic subtypes. Methods Most circulating HIV-1 isolates in China are composed of clades Thai-B, CRF_BC and CRF01_AE. In order to construct DNA vaccines against these 3 HIV-1 subtypes, DNA vaccines carrying the gp120 regions from HIV-1 isolates of GX48（AE）, GX79（AE）, NX22（BC）, GS22（BC）, HN24（Thai-B） were constructed. Expression of gp120 from these DNA vaccines was detected by Western blotting in transiently transfected 293T cells. Pilot immunizations of New Zealand white rabbits were performed using the strategy of ＂DNA prime plus protein boost＂ and the neutralizing antibody response was detected in a Tzm-bl cell based assay against different HIV-1 strains. Results Response of gp120-specific antibody was relatively low after DNA primes （mean titer=10^4.72）; however, the titer of gp120-specific antibody went up with 2 protein boosts （mean titer=10^6.81）. Above all, neutralizing antibody （Nab） titers induced by this combined approach were much better than those elicited by DNA or protein used alone （P 〈0.01）. Neutralizing activities of immunized rabbit sera against several pseudoviruses and laboratorial strains were evaluated, most rabbit sera primed with monovalent vaccine were capable of neutralizing only 1 of 5 viruses, however, sera primed with the polyvalent DNA vaccines were able to neutralize at least 2 of 5 viruses. Conclusion Polyvalent DNA prime plus protein boost is an effective immunization strategy to broaden the neutralization breadth and further research should be performed on the basis of this pilot study.

关 键 词：human immunodeficiency virus type 1 DNA vaccine DNA prime protein boost neutralizing antibody 

分 类 号：S858.315.3[农业科学—临床兽医学] Q513.2[农业科学—兽医学]