title: An HIV-1 envelope immunogen with W427S mutation in CD4 binding site induced more T follicular helper memory cells and reduced non-specific antibody responses.
abstract: The CD4 binding site (CD4BS) of the HIV-1 envelope glycoprotein (Env) contains epitopes for broadly neutralizing antibody (nAb) and is the target for the vaccine development. However, the CD4BS core including residues 425-430 overlaps the B cell superantigen site and may be related to B cell exhaustion in HIV-1 infection. Furthermore, production of nAb and high-affinity plasma cells needs germinal center reaction and the help of T follicular helper (Tfh) cells. We believe that strengthening the ability of Env CD4BS in inducing Tfh response and decreasing the effects of the superantigen are the strategies for eliciting nAb and development of HIV-1 vaccine. We constructed a gp120 mutant W427S of an HIV-1 primary R5 strain and examined its ability in the elicitation of Ab and the production of Tfh by immunization of BALB/c mice. We found that the trimeric wild-type gp120 can induce more non-specific antibody-secreting plasma cells, higher serum IgG secretion, and more Tfh cells by splenocyte. The modified W427S gp120 elicits higher levels of specific binding antibodies as well as nAbs though it produces less Tfh cells. Furthermore, higher Tfh cell frequency does not correlate to the specific binding Abs or nAbs indicating that the wild-type gp120 induced some non-specific Tfh that did not contribute to the production of specific Abs. This gp120 mutant led to more memory Tfh production, especially, the effector memory Tfh cells. Taken together, W427S gp120 could induce higher level of specific binding and neutralizing Ab production that may be associated with the reduction of non-specific Tfh but strengthening of the memory Tfh.
authors.affiliation: Department of Microbiology, Harbin Medical University, Harbin, China.
authors.forename: Hao-Tong
authors.initials: HT
authors.lastname: Yu
authors.affiliation: Department of Microbiology, Harbin Medical University, Harbin, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Tian
authors.affiliation: Department of Microbiology, Harbin Medical University, Harbin, China; Heilongjiang Provincial Key Lab for Infection and Immunity, Key Lab of Etiology of Heilongjiang Province Education Bureau, Harbin, China.
authors.forename: Jia-Ye
authors.initials: JY
authors.lastname: Wang
authors.affiliation: Department of Microbiology, Harbin Medical University, Harbin, China.
authors.forename: Cai-Xia
authors.initials: CX
authors.lastname: Guo
authors.affiliation: Department of Microbiology, Harbin Medical University, Harbin, China; Heilongjiang Provincial Key Lab for Infection and Immunity, Key Lab of Etiology of Heilongjiang Province Education Bureau, Harbin, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Microbiology, Harbin Medical University, Harbin, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Microbiology, Harbin Medical University, Harbin, China; Heilongjiang Provincial Key Lab for Infection and Immunity, Key Lab of Etiology of Heilongjiang Province Education Bureau, Harbin, China.
authors.forename: Di
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Microbiology, Harbin Medical University, Harbin, China; Heilongjiang Provincial Key Lab for Infection and Immunity, Key Lab of Etiology of Heilongjiang Province Education Bureau, Harbin, China.
authors.forename: Feng-Min
authors.initials: FM
authors.lastname: Zhang
authors.affiliation: Department of Microbiology, Harbin Medical University, Harbin, China; Heilongjiang Provincial Key Lab for Infection and Immunity, Key Lab of Etiology of Heilongjiang Province Education Bureau, Harbin, China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhuang
authors.affiliation: Department of Microbiology, Harbin Medical University, Harbin, China; Heilongjiang Provincial Key Lab for Infection and Immunity, Key Lab of Etiology of Heilongjiang Province Education Bureau, Harbin, China; Department of Parasitology, Harbin Medical University, Harbin, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Ling
mesh_terms: D016915:AIDS Vaccines / Q000276:immunology; D000818:Animals; D057134:Antibodies, Neutralizing / Q000276:immunology*; D000918:Antibody Specificity; D001665:Binding Sites; D015704:CD4 Antigens / Q000378:metabolism; D005260:Female; D015483:HIV Antibodies / Q000097:blood / Q000276:immunology*; D015699:HIV Envelope Protein gp120 / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D015497:HIV-1 / Q000235:genetics / Q000276:immunology*; D007156:Immunologic Memory; D051379:Mice; D008807:Mice, Inbred BALB C; D009154:Mutation; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
chemical_list: D016915:AIDS Vaccines; D057134:Antibodies, Neutralizing; D015704:CD4 Antigens; D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; C514793:gp120 protein, Human immunodeficiency virus 1