scholarly journals A Novel MVA-Based HIV Vaccine Candidate (MVA-gp145-GPN) Co-Expressing Clade C Membrane-Bound Trimeric gp145 Env and Gag-Induced Virus-Like Particles (VLPs) Triggered Broad and Multifunctional HIV-1-Specific T Cell and Antibody Responses

Viruses ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 160 ◽  
Author(s):  
Beatriz Perdiguero ◽  
Cristina Sánchez-Corzo ◽  
Carlos Sorzano ◽  
Lidia Saiz ◽  
Pilar Mediavilla ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Vaccine Candidate ◽  
Hiv Vaccine ◽  
Replication Capacity ◽  
Virus Like Particles ◽  
Modified Vaccinia Virus Ankara ◽  
Clade C ◽  
Membrane Bound ◽  
Hiv 1

The development of an effective Human Immunodeficiency Virus (HIV) vaccine that is able to stimulate both the humoral and cellular HIV-1-specific immune responses remains a major priority challenge. In this study, we described the generation and preclinical evaluation of single and double modified vaccinia virus Ankara (MVA)-based candidates expressing the HIV-1 clade C membrane-bound gp145(ZM96) trimeric protein and/or the Gag(ZM96)-Pol-Nef(CN54) (GPN) polyprotein that was processed to form Gag-induced virus-like particles (VLPs). In vitro characterization of MVA recombinants revealed the stable integration of HIV-1 genes without affecting its replication capacity. In cells that were infected with Env-expressing viruses, the gp145 protein was inserted into the plasma membrane exposing critical epitopes that were recognized by broadly neutralizing antibodies (bNAbs), whereas Gag-induced VLPs were released from cells that were infected with GPN-expressing viruses. VLP particles as well as purified MVA virions contain Env and Gag visualized by immunoelectron microscopy and western-blot of fractions that were obtained after detergent treatments of purified virus particles. In BALB/c mice, homologous MVA-gp145-GPN prime/boost regimen induced broad and polyfunctional Env- and Gag-specific CD4 T cells and antigen-specific T follicular helper (Tfh) and Germinal Center (GC) B cells, which correlated with robust HIV-1-specific humoral responses. Overall, these results support the consideration of MVA-gp145-GPN vector as a potential vaccine candidate against HIV-1.

Induction of a Robust Humoral Response using HIV-1 VLPMPER-V3 as a Novel Candidate Vaccine in BALB/c Mice

2019 ◽  
Vol 17 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Fatemeh Tohidi ◽  
Seyed Mehdi Sadat ◽  
Azam Bolhassani ◽  
Ramin Yaghobi ◽  
Mona Sadat Larijani
Keyword(s):  
T Cell ◽  
Neutralizing Antibodies ◽  
Vaccine Candidate ◽  
Humoral Response ◽  
Cellular Responses ◽  
Immunodeficiency Virus ◽  
Potential Vaccine ◽  
Humoral Responses ◽  
Hiv 1

Background: Several approaches have not been successful to suppress HIV (Human immunodeficiency virus) infection among infected individuals or to prevent it yet. In order to expand strong HIV specific humoral and cellular responses, Virus-like particles (VLPs) as potential vaccines show significant increase in neutralizing antibodies secretion, T-cell count and also secretion of cytokines. Objective: This study aimed at immunological evaluation of VLPs harboring high copy of MPERV3 in BALB/c mice. Methods: Female BALB/c mice were immunized with homologous and heterologous primeboosting regimens of HIV-1 VLPMPER-V3. Their immune responses were evaluated for humoral responses (Total IgG and IgG isotyping) and cellular responses (IFN-γ, IL-5 secretion, in vitro CTL assay and T cell proliferation) and compared in immunized mice. Results: The data showed robust induction of humoral response in mice groups which received different regimens of VLP. Furthermore, analysis of cytokine profile indicated that the highest IL-5 secretion was related to VLP+M50 group and confirmed the dominance of Th2 immunity in this group. Conclusion: This study showed that VLP MPER-V3 as a potential vaccine candidate has the potency as an effective prophylactic vaccine and this finding guarantees further investigations to achieve a promising HIV-1 vaccine candidate.

scholarly journals Virological and Immunological Characterization of Novel NYVAC-Based HIV/AIDS Vaccine Candidates Expressing Clade C Trimeric Soluble gp140(ZM96) and Gag(ZM96)-Pol-Nef(CN54) as Virus-Like Particles

2014 ◽  
Vol 89 (2) ◽  
pp. 970-988 ◽  
Author(s):  
Beatriz Perdiguero ◽  
Carmen Elena Gómez ◽  
Victoria Cepeda ◽  
Lucas Sánchez-Sampedro ◽  
Juan García-Arriaza ◽  
...  
Keyword(s):  
Immune Responses ◽  
Human Cells ◽  
Hiv Vaccine ◽  
Phase Iii ◽  
Newborn Mice ◽  
Vaccine Candidates ◽  
Virus Like Particles ◽  
Clade C ◽  
Hiv 1 ◽  
Hiv Aids

ABSTRACTThe generation of vaccines against HIV/AIDS able to induce long-lasting protective immunity remains a major goal in the HIV field. The modest efficacy (31.2%) against HIV infection observed in the RV144 phase III clinical trial highlighted the need for further improvement of HIV vaccine candidates, formulation, and vaccine regimen. In this study, we have generated two novel NYVAC vectors, expressing HIV-1 clade C gp140(ZM96) (NYVAC-gp140) or Gag(ZM96)-Pol-Nef(CN54) (NYVAC-Gag-Pol-Nef), and defined their virological and immunological characteristics in cultured cells and in mice. The insertion of HIV genes does not affect the replication capacity of NYVAC recombinants in primary chicken embryo fibroblast cells, HIV sequences remain stable after multiple passages, and HIV antigens are correctly expressed and released from cells, with Env as a trimer (NYVAC-gp140), while in NYVAC-Gag-Pol-Nef-infected cells Gag-induced virus-like particles (VLPs) are abundant. Electron microscopy revealed that VLPs accumulated with time at the cell surface, with no interference with NYVAC morphogenesis. Both vectors trigger specific innate responses in human cells and show an attenuation profile in immunocompromised adult BALB/c and newborn CD1 mice after intracranial inoculation. Analysis of the immune responses elicited in mice after homologous NYVAC prime/NYVAC boost immunization shows that recombinant viruses induced polyfunctional Env-specific CD4 or Gag-specific CD8 T cell responses. Antibody responses against gp140 and p17/p24 were elicited. Our findings showed important insights into virus-host cell interactions of NYVAC vectors expressing HIV antigens, with the activation of specific immune parameters which will help to unravel potential correlates of protection against HIV in human clinical trials with these vectors.IMPORTANCEWe have generated two novel NYVAC-based HIV vaccine candidates expressing HIV-1 clade C trimeric soluble gp140 (ZM96) and Gag(ZM96)-Pol-Nef(CN54) as VLPs. These vectors are stable and express high levels of both HIV-1 antigens. Gag-induced VLPs do not interfere with NYVAC morphogenesis, are highly attenuated in immunocompromised and newborn mice after intracranial inoculation, trigger specific innate immune responses in human cells, and activate T (Env-specific CD4 and Gag-specific CD8) and B cell immune responses to the HIV antigens, leading to high antibody titers against gp140. For these reasons, these vectors can be considered vaccine candidates against HIV/AIDS and currently are being tested in macaques and humans.

scholarly journals HIV-1-Based Virus-like Particles that Morphologically Resemble Mature, Infectious HIV-1 Virions

Viruses ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 507 ◽  
Author(s):  
Christopher A. Gonelli ◽  
Georges Khoury ◽  
Rob J. Center ◽  
Damian F.J. Purcell
Keyword(s):  
T Cell ◽  
Dna Vaccine ◽  
Neutralizing Antibodies ◽  
T Cell Responses ◽  
Expression Vectors ◽  
Virus Like Particles ◽  
Cell Responses ◽  
Hiv 1

A prophylactic vaccine eliciting both broad neutralizing antibodies (bNAbs) to the HIV-1 envelope glycoprotein (Env) and strong T cell responses would be optimal for preventing HIV-1 transmissions. Replication incompetent HIV-1 virus-like particles (VLPs) offer the opportunity to present authentic-structured, virion-associated Env to elicit bNAbs, and also stimulate T cell responses. Here, we optimize our DNA vaccine plasmids as VLP expression vectors for efficient Env incorporation and budding. The original vector that was used in human trials inefficiently produced VLPs, but maximized safety by inactivating RNA genome packaging, enzyme functions that are required for integration into the host genome, and deleting accessory proteins Vif, Vpr, and Nef. These original DNA vaccine vectors generated VLPs with incomplete protease-mediated cleavage of Gag and were irregularly sized. Mutations to restore function within the defective genes revealed that several of the reverse transcriptase (RT) deletions mediated this immature phenotype. Here, we made efficient budding, protease-processed, and mature-form VLPs that resembled infectious virions by introducing alternative mutations that completely removed the RT domain, but preserved most other safety mutations. These VLPs, either expressed from DNA vectors in vivo or purified after expression in vitro, are potentially useful immunogens that can be used to elicit antibody responses that target Env on fully infectious HIV-1 virions.

scholarly journals Prime-Boost Immunizations with DNA, Modified Vaccinia Virus Ankara, and Protein-Based Vaccines Elicit Robust HIV-1 Tier 2 Neutralizing Antibodies against the CAP256 Superinfecting Virus

2019 ◽  
Vol 93 (8) ◽  
Author(s):  
Michiel T. van Diepen ◽  
Rosamund Chapman ◽  
Nicola Douglass ◽  
Shireen Galant ◽  
Penny L. Moore ◽  
...  
Keyword(s):  
Vaccinia Virus ◽  
Envelope Protein ◽  
Neutralizing Antibodies ◽  
High Titer ◽  
Viral Envelope ◽  
Sub Saharan Africa ◽  
Tier 2 ◽  
Modified Vaccinia Virus Ankara ◽  
Membrane Bound ◽  
Hiv 1

ABSTRACTA vaccine regimen that elicits broadly neutralizing antibodies (bNAbs) is a major goal in HIV-1 vaccine research. In this study, we assessed the immunogenicity of the CAP256 superinfecting viral envelope (CAP256 SU) protein delivered by modified vaccinia virus Ankara (MVA) and DNA vaccines in different prime-boost combinations followed by a soluble protein (P) boost. The envelope protein (Env) contained a flexible glycine linker and I559P mutation. Trimer-specific bNAbs PGT145, PG16, and CAP256 VRC26_08 efficiently bound to the membrane-bound CAP256 envelope expressed on the surface of cells transfected or infected with the DNA and MVA vaccines. The vaccines were tested in two different vaccination regimens in rabbits. Both regimens elicited autologous tier 2 neutralizing antibodies (NAbs) and high-titer binding antibodies to the matching CAP256 Env and CAP256 V1V2 loop scaffold. The immunogenicity of DNA and MVA vaccines expressing membrane-bound Env alone was compared to that of Env stabilized in a more native-like conformation on the surface of Gag virus-like particles (VLPs). The inclusion of Gag in the DNA and MVA vaccines resulted in earlier development of tier 2 NAbs for both vaccination regimens. In addition, a higher proportion of the rabbits primed with DNA and MVA vaccines that included Gag developed tier 2 NAbs than did those primed with vaccine expressing Env alone. Previously, these DNA and MVA vaccines expressing subtype C mosaic HIV-1 Gag were shown to elicit strong T cell responses in mice. Here we show that when the CAP256 SU envelope protein is included, these vaccines elicit autologous tier 2 NAbs.IMPORTANCEA vaccine is urgently needed to combat HIV-1, particularly in sub-Saharan Africa, which remains disproportionately affected by the AIDS pandemic and accounts for the majority of new infections and AIDS-related deaths. In this study, two different vaccination regimens were compared. Rabbits that received two DNA primes followed by two modified vaccinia virus Ankara (MVA) and two protein inoculations developed better immune responses than those that received two MVA and three protein inoculations. In addition, DNA and MVA vaccines that expressed mosaic Gag VLPs presenting a stabilized Env antigen elicited better responses than Env alone, which supports the inclusion of Gag VLPs in an HIV-1 vaccine.

scholarly journals Changes at V2 apex of HIV-1 Clade C trimer enhance elicitation of autologous neutralizing and broad V1V2-scaffold antibodies

2021 ◽  
Author(s):  
Anusmita Sahoo ◽  
Edgar A Hodge ◽  
Celia LaBranche ◽  
Tiffany Turner Styles ◽  
Xiaoying Shen ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Wild Type ◽  
Human Trial ◽  
Specific Antibodies ◽  
Type Protein ◽  
Wild Type Protein ◽  
Clade C ◽  
Intrinsic Dynamic ◽  
Hiv 1

HIV-1 clade C envelope immunogens that elicit both neutralizing and non-neutralizing V1V2-scaffold specific antibodies (protective correlates from RV144 human trial) are urgently needed due to the prevalence of this clade in the most impacted regions worldwide. To achieve this, we introduced structure-guided changes followed by consensus-C sequence-guided optimizations at the V2-region to generate UFO-v2-RQH173 trimer. This improved the abundance of native-like trimers and carried an intrinsic dynamic V2-loop. Following immunization of rabbits, the wild-type protein failed to elicit any autologous neutralizing antibodies but UFO-v2-RQH173 elicited both autologous neutralizing and broad V1V2-scaffold antibodies. The variant with 173Y modification in V2-region, most prevalent among HIV-1 sequences, showed decreased ability in displaying native-like V1V2 epitope with time in-vitro and elicited antibodies with lower neutralizing and higher V1V2-scaffold activities. Our results identify a clade C C.1086-UFO-v2-RQH173 trimer capable of eliciting improved neutralizing and V1V2-scaffold antibodies, and reveal the importance of V2-region in tuning this.

scholarly journals MVA-B AS HIV/AIDS VACCINE CANDIDATE: FROM BASIC SCIENCE TO PROPHYLACTIC AND THERAPEUTIC CLINICAL TRIALS

2020 ◽  
pp. 29-60
Author(s):  
Carmen Elena Gómez Rodríguez
Keyword(s):  
Clinical Trials ◽  
Vaccine Candidate ◽  
Therapeutic Vaccine ◽  
Basic Knowledge ◽  
Antigen Delivery ◽  
Modified Vaccinia Virus Ankara ◽  
Hiv 1 ◽  
Hiv Aids

The highly attenuated poxvirus strain modified vaccinia virus Ankara (MVA) has reached maturity as antigen delivery system and as a vaccine candidate against a broad spectrum of infectious diseases. This has been largely recognized from research on virus–host cell interactions, gene expression profiling, virus distribution and immunological studies in preclinical and clinical trials. This review includes our main contributions from the basic knowledge of the biology of the MVA vector, both in vitro and in vivo, in comparison with the attenuated NYVAC strain, to its evaluation as a vaccine candidate against HIV/AIDS in clinical trials. We will detail the generation and characterization of the recombinant poxvirus vector MVA expressing the HIV-1 Env, Gag, Pol and Nef antigens from clade B (referred as MVA-B) and review the preclinical data that supported the evaluation of MVA-B as the first in human HIV-1 prophylactic and therapeutic vaccine in Spain. In addition, we will assess the results of clinical trials and discuss the research projects we are currently working on considering the latest scientific advances in the HIV vaccine field.

scholarly journals Immunogenicity of HIV-1-Based Virus-Like Particles with Increased Incorporation and Stability of Membrane-Bound Env

Vaccines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 239
Author(s):  
Christopher A. Gonelli ◽  
Hannah A. D. King ◽  
Charlene Mackenzie ◽  
Secondo Sonza ◽  
Rob J. Center ◽  
...  
Keyword(s):  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Neutralization Activity ◽  
Virus Like Particles ◽  
Antibody Isotypes ◽  
Immunodeficiency Virus ◽  
Proline Substitution ◽  
Membrane Bound ◽  
Antibody Epitopes ◽  
Hiv 1

An optimal prophylactic vaccine to prevent human immunodeficiency virus (HIV-1) transmission should elicit protective antibody responses against the HIV-1 envelope glycoprotein (Env). Replication-incompetent HIV-1 virus-like particles (VLPs) offer the opportunity to present virion-associated Env with a native-like structure during vaccination that closely resembles that encountered on infectious virus. Here, we optimized the incorporation of Env into previously designed mature-form VLPs (mVLPs) and assessed their immunogenicity in mice. The incorporation of Env into mVLPs was increased by replacing the Env transmembrane and cytoplasmic tail domains with those of influenza haemagglutinin (HA-TMCT). Furthermore, Env was stabilized on the VLP surface by introducing an interchain disulfide and proline substitution (SOSIP) mutations typically employed to stabilize soluble Env trimers. The resulting mVLPs efficiently presented neutralizing antibody epitopes while minimizing exposure of non-neutralizing antibody sites. Vaccination of mice with mVLPs elicited a broader range of Env-specific antibody isotypes than Env presented on immature VLPs or extracellular vesicles. The mVLPs bearing HA-TMCT-modified Env consistently induced anti-Env antibody responses that mediated modest neutralization activity. These mVLPs are potentially useful immunogens for eliciting neutralizing antibody responses that target native Env epitopes on infectious HIV-1 virions.

scholarly journals Effect of Small Polyanions on In Vitro Assembly of Selected Members of Alpha-, Beta- and Gammaretroviruses

Viruses ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 129
Author(s):  
Alžběta Dostálková ◽  
Barbora Vokatá ◽  
Filip Kaufman ◽  
Pavel Ulbrich ◽  
Tomáš Ruml ◽  
...  
Keyword(s):  
Equine Infectious Anemia Virus ◽  
Electron Tomography ◽  
Leukemia Virus ◽  
Virus Like Particles ◽  
Rous Sarcoma ◽  
Sarcoma Virus ◽  
Anemia Virus ◽  
Immature Virus ◽  
Hiv 1

The assembly of a hexameric lattice of retroviral immature particles requires the involvement of cell factors such as proteins and small molecules. A small, negatively charged polyanionic molecule, myo-inositol hexaphosphate (IP6), was identified to stimulate the assembly of immature particles of HIV-1 and other lentiviruses. Interestingly, cryo-electron tomography analysis of the immature particles of two lentiviruses, HIV-1 and equine infectious anemia virus (EIAV), revealed that the IP6 binding site is similar. Based on this amino acid conservation of the IP6 interacting site, it is presumed that the assembly of immature particles of all lentiviruses is stimulated by IP6. Although this specific region for IP6 binding may be unique for lentiviruses, it is plausible that other retroviral species also recruit some small polyanion to facilitate the assembly of their immature particles. To study whether the assembly of retroviruses other than lentiviruses can be stimulated by polyanionic molecules, we measured the effect of various polyanions on the assembly of immature virus-like particles of Rous sarcoma virus (RSV), a member of alpharetroviruses, Mason-Pfizer monkey virus (M-PMV) representative of betaretroviruses, and murine leukemia virus (MLV), a member of gammaretroviruses. RSV, M-PMV and MLV immature virus-like particles were assembled in vitro from truncated Gag molecules and the effect of selected polyanions, myo-inostol hexaphosphate, myo-inositol, glucose-1,6-bisphosphate, myo-inositol hexasulphate, and mellitic acid, on the particles assembly was quantified. Our results suggest that the assembly of immature particles of RSV and MLV was indeed stimulated by the presence of myo-inostol hexaphosphate and myo-inositol, respectively. In contrast, no effect on the assembly of M-PMV as a betaretrovirus member was observed.

scholarly journals A Conformational Transition Observed in Single HIV-1 Gag Molecules during In Vitro Assembly of Virus-Like Particles

2014 ◽  
Vol 88 (6) ◽  
pp. 3577-3585 ◽  
Author(s):  
J. B. Munro ◽  
A. Nath ◽  
M. Farber ◽  
S. A. K. Datta ◽  
A. Rein ◽  
...  
Keyword(s):  
Conformational Transition ◽  
Virus Like Particles ◽  
In Vitro Assembly ◽  
Hiv 1

scholarly journals Replication-Competent NYVAC-KC Yields Improved Immunogenicity to HIV-1 Antigens in Rhesus Macaques Compared to Nonreplicating NYVAC

2018 ◽  
Vol 93 (3) ◽  
Author(s):  
Karen V. Kibler ◽  
Benedikt Asbach ◽  
Beatriz Perdiguero ◽  
Juan García-Arriaza ◽  
Nicole L. Yates ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Vaccine Candidate ◽  
Rhesus Macaques ◽  
Phase Iii ◽  
Effective Vaccine ◽  
Phase Iii Clinical Trial ◽  
Boost Regimen ◽  
Clade C ◽  
The One ◽  
Hiv 1

ABSTRACT As part of the continuing effort to develop an effective HIV vaccine, we generated a poxviral vaccine vector (previously described) designed to improve on the results of the RV144 phase III clinical trial. The construct, NYVAC-KC, is a replication-competent, attenuated recombinant of the vaccinia virus strain NYVAC. NYVAC is a vector that has been used in many previous clinical studies but is replication deficient. Here, we report a side-by-side comparison of replication-restricted NYVAC and replication-competent NYVAC-KC in a nonhuman primate study, which utilized a prime-boost regimen similar to that of RV144. NYVAC-C and NYVAC-C-KC express the HIV-1 antigens gp140, and Gag/Gag-Pol-Nef-derived virus-like particles (VLPs) from clade C and were used as the prime, with recombinant virus plus envelope protein used as the boost. In nearly every T and B cell immune assay against HIV-1, including neutralization and antibody binding, NYVAC-C-KC induced a greater immune response than NYVAC-C, indicating that replication competence in a poxvirus may improve upon the modestly successful regimen used in the RV144 clinical trial. IMPORTANCE Though the RV144 phase III clinical trial showed promise that an effective vaccine against HIV-1 is possible, a successful vaccine will require improvement over the vaccine candidate (ALVAC) used in the RV144 study. With that goal in mind, we have tested in nonhuman primates an attenuated but replication-competent vector, NYVAC-KC, in direct comparison to its parental vector, NYVAC, which is replication restricted in human cells, similar to the ALVAC vector used in RV144. We have utilized a prime-boost regimen for administration of the vaccine candidate that is similar to the one used in the RV144 study. The results of this study indicate that a replication-competent poxvirus vector may improve upon the effectiveness of the RV144 clinical trial vaccine candidate.

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