M

M.R. VRA017, VRA019, and VRA177 exhibited high specificity to VRC01 antibody. Immunized mice produced Env-binding antibodies which neutralize eight of twelve HIV-1 Tier 2 pseudoviruses. Molecular modelling revealed a shape complementarity between VRA proteins and a part of VRC01 gp120 interacting surface. Interpretation This strategy based on the identification of protein replicas of broadly neutralizing antibody paratope represents a novel approach in HIV-1 vaccine development. This approach is not affected by low NVP-CGM097 immunogenicity of neutralization-sensitive epitopes, variability, and unique biochemical properties of HIV-1 Env used as a crucial antigen in the majority of contemporary tested vaccines. Fund Czech Health Research Council 15-32198A, Ministry of Health, Czech Republic. Keywords: Neutralizing antibody, Albumin-binding domain scaffold, Combinatorial protein library, Antibody paratope mimetics, Protein docking, HIV-1 vaccine Research in context Evidence before this study The development of effective vaccine preventing HIV-1 virus infection is hindered by enormous antigenic variability of the virus envelope glycoprotein (Env) and unique biological and immunological properties of Env as the most promising target for HIV-1-neutralizing antibody. NVP-CGM097 Functional studies of a rare population of patients who control the infection even without antiretroviral therapy led to the discovery of monoclonal antibodies neutralizing a broad spectrum of Env variants (bn-mAb). The generation of such bn-Abs is a long-term process lasting years and difficult to elicit by conventional vaccination. Added value of this study High complexity combinatorial non-glycosylated protein library is promising for identification of protein variants mimicking Env domains recognized by HIV-1 bn-mAb such as VRC01. Such variants are potentially effective immunogens for elicitation of antibodies analogous in epitope acknowledgement to initially used bn-mAb. We recognized the three most VRC01-specific protein variants designated VRA017, VRA019, and VRA177. Molecular modelling exposed a shape complementarity between VRA proteins and a part of NVP-CGM097 VRC01 gp120 interacting surface. Vaccination of experimental mice with VRA variants succeed to elicit Env binding- and panel of HIV-1 NVP-CGM097 pseudoviruses-neutralizing antibodies. Implications of all the available evidence Strategy based on the recognition of small proteins mimicking epitopes identified by selected bn-mAb represents a encouraging approach for the development of vaccines able to induce NVP-CGM097 antibodies analogous to known protecting ones recognized in infection-controlling subjects. This approach is definitely not affected by HIV-1 Env low immunogenicity of neutralization epitopes, variability, and unique biochemical and immunological properties of protecting epitopes, such as those on HIV-1 Env. Furthermore, such proteins are easy to express with high yield inside a prokaryote manifestation system, are conformationally stable, and are not revised by posttranslational changes such as glycosylation which in the HIV-1 Env show considerable micro- and macro-heterogeneity. Alt-text: Unlabelled Package 1.?Intro HIV/AIDS is a global pandemic resulting in an estimated 354 million deaths worldwide. Irrespective of rigorous research, no commercial vaccine is available. The most important obstacles are an enormous HIV-1 antigenic variability and unique biochemical, biological, and immunological properties of the most promising vaccine candidate, HIV-1 envelope (Env) glycoprotein which is responsible for HIV-1 attachment to and the entry into the sponsor cell [1,2]. New strategies in HIV-1 vaccine development were motivated after recognition of a few antibodies able to neutralize a broad range of HIV-1 Env variants (bn-mAbs) which limit viraemia, as demonstrated for elite neutralizers [[2], [3], [4]]. The generation of HIV-1-specific bn-mAbs under natural conditions is definitely a long-term process enduring years and hard to be elicited by standard vaccination. The majority of identified bn-mAbs show unique properties including a long HCDR3, amazing frequencies of V(D)J mutations and poly- or autoreactivity with human being lipids and proteins, which seem to be a crucial obstacle for the development of a successful vaccination strategy [[5], [6], [7]]. Despite growing knowledge about the molecular structure of HIV-1 Env, its connection with bn-mAbs, and mechanisms of immune response development, currently tested vaccine induce immune response with still limited effectiveness and breadth [1,[8], [9], [10], [11]]. We developed a new strategy for elicitation of bn-mAbs based on directed evolution of proteins, and recognition and preparation of recombinant protein replicas of epitopes identified by well-characterized bn-mAbs. These proteins can be used as antigens for building of a vaccine, inducing production of serum antibodies with specificity and neutralization potential analogous to the used bn-mAb. The strategy utilizes manufactured artificial binding proteins Rabbit polyclonal to ZNF101 identified using a highly complex combinatorial library derived from albumin-binding website (ABD).