Immunogenicity and Protective Efficacy of DNA Vaccines Expressing Rhesus Cytomegalovirus Glycoprotein B, Phosphoprotein 65-2, and Viral Interleukin-10 in Rhesus Macaques

ABSTRACT Rhesus cytomegalovirus (RhCMV) infection of macaques exhibits strong similarities to human CMV (HCMV) persistence and pathogenesis. The immunogenicity of DNA vaccines encoding three RhCMV proteins (a truncated version of glycoprotein B lacking the transmembrane region and endodomain [gBΔTM], phosphoprotein 65-2 [pp65-2], and viral interleukin-10 [vIL-10]) was evaluated in rhesus macaques. Two groups of monkeys (four per group) were genetically immunized four times with a mixture of either pp65-2 and gBΔTM or pp65-2, vIL-10, and gBΔTM. The vaccinees developed anti-gB and anti-pp65-2 antibodies in addition to pp65-2 cellular responses after the second booster immunization, with rapid responses observed with subsequent DNA injections. Weak vIL-10 immune responses were detected in two of the four immunized animals. Neutralizing antibodies were detected in seven monkeys, although titers were weak compared to those observed in naturally infected animals. The immunized monkeys and naïve controls were challenged intravenously with 105 PFU of RhCMV. Anamnestic binding and neutralizing antibody responses were observed 1 week postchallenge in the vaccinees. DNA vaccination-induced immune responses significantly decreased peak viral loads in the immunized animals compared to those in the controls. No difference in peak viral loads was observed between the pp65-2/gBΔTM DNA- and pp65-2/vIL-10/gBΔTM-vaccinated groups. Antibody responses to nonvaccine antigens were lower postchallenge in both vaccine groups than in the controls, suggesting long-term control of RhCMV protein expression. These data demonstrated that DNA vaccines targeting the RhCMV homologues of HCMV gB and pp65 altered the course of acute and persistent RhCMV infection in a primate host.

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Immunogenicity, safety, and efficacy of sequential immunizations with an SIV-based IDLV expressing CH505 Envs

npj Vaccines ◽

10.1038/s41541-020-00252-w ◽

2020 ◽

Vol 5 (1) ◽

Author(s):

Maria Blasi ◽

Donatella Negri ◽

Kevin O. Saunders ◽

Erich J. Baker ◽

Hannah Stadtler ◽

...

Keyword(s):

Immune Responses ◽

Neutralizing Antibodies ◽

Lentiviral Vector ◽

Rhesus Macaques ◽

Infected Individual ◽

Neutralizing Antibody ◽

Antibody Responses ◽

Safety And Efficacy ◽

Env Protein ◽

Hiv 1

AbstractA preventative HIV-1 vaccine is an essential intervention needed to halt the HIV-1 pandemic. Neutralizing antibodies protect against HIV-1 infection in animal models, and thus an approach toward a protective HIV-1 vaccine is to induce broadly cross-reactive neutralizing antibodies (bnAbs). One strategy to achieve this goal is to define envelope (Env) evolution that drives bnAb development in infection and to recreate those events by vaccination. In this study, we report the immunogenicity, safety, and efficacy in rhesus macaques of an SIV-based integrase defective lentiviral vector (IDLV) expressing sequential gp140 Env immunogens derived from the CH505 HIV-1-infected individual who made the CH103 and CH235 bnAb lineages. Immunization with IDLV expressing sequential CH505 Envs induced higher magnitude and more durable binding and neutralizing antibody responses compared to protein or DNA +/− protein immunizations using the same sequential envelopes. Compared to monkeys immunized with a vector expressing Envs alone, those immunized with the combination of IDLV expressing Env and CH505 Env protein demonstrated improved durability of antibody responses at six months after the last immunization as well as lower peak viremia and better virus control following autologous SHIV-CH505 challenge. There was no evidence of vector mobilization or recombination in the immunized and challenged monkeys. Although the tested vaccines failed to induce bnAbs and to mediate significant protection following SHIV-challenge, our results show that IDLV proved safe and successful at inducing higher titer and more durable immune responses compared to other vaccine platforms.

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Neutralization of rhesus cytomegalovirus IL-10 reduces horizontal transmission and alters long-term immunity

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1903317116 ◽

2019 ◽

Vol 116 (26) ◽

pp. 13036-13041 ◽

Cited By ~ 4

Author(s):

Jesse D. Deere ◽

W. L. William Chang ◽

Andradi Villalobos ◽

Kimberli A. Schmidt ◽

Ashlesha Deshpande ◽

...

Keyword(s):

Immune Responses ◽

Persistent Infection ◽

Vaccine Development ◽

Rhesus Macaques ◽

Horizontal Transmission ◽

Severe Disease ◽

Interleukin 10 ◽

Primate Model ◽

Host Immune Responses ◽

Rhesus Cytomegalovirus

Human cytomegalovirus (HCMV) causes severe disease in infants and immunocompromised people. There is no approved HCMV vaccine, and vaccine development strategies are complicated by evidence of both persistent infection and reinfection of people with prior immunity. The greatest emphasis has been placed on reducing transmission to seronegative pregnant women to prevent vertical transmission and its potentially severe sequelae. Increasing evidence suggests that the earliest host–HCMV interactions establish conditions for viral persistence, including evasion of host immune responses to the virus. Using a nonhuman primate model of HCMV infection, we show that rhesus macaques immunized against viral interleukin-10 (IL-10) manifest delayed rhesus cytomegalovirus (RhCMV) acquisition and altered immune responses to the infection when it does occur. Among animals with the greatest antiviral IL-10–neutralizing activity, the timing of RhCMV seroconversion was delayed by an average of 12 weeks. After acquisition, such animals displayed an antibody response to the new infection, which peaked as expected after 2 weeks but then declined rapidly. In contrast, surprisingly, vaccination with glycoprotein B (gB) protein had no discernible impact on these outcomes. Our results demonstrate that viral IL-10 is a key regulator of successful host immune responses to RhCMV. Viral IL-10 is, therefore, an important target for vaccine strategies against cytomegalovirus (CMV). Furthermore, given the immunoregulatory function of viral IL-10, targeting this protein may prove synergistic with other vaccine therapies and targets. Our study also provides additional evidence that the earliest host–CMV interactions can have a significant impact on the nature of persistent infection.

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Antibody responses to rhesus cytomegalovirus glycoprotein B in naturally infected rhesus macaques

Journal of General Virology ◽

10.1099/vir.0.19508-0 ◽

2003 ◽

Vol 84 (12) ◽

pp. 3371-3379 ◽

Cited By ~ 33

Author(s):

Yujuan Yue ◽

Shan Shan Zhou ◽

Peter A. Barry

Keyword(s):

Specific Antibody ◽

Transmembrane Domain ◽

Solid Phase ◽

Rhesus Macaques ◽

Antibody Responses ◽

Full Length ◽

Glycoprotein B ◽

Primate Model ◽

Specific Antibodies ◽

Rhesus Cytomegalovirus

Rhesus cytomegalovirus (RhCMV) exhibits strong parallels with human CMV (HCMV) in terms of nucleic and amino acid identities, natural history, and mechanisms of persistence and pathogenesis in its natural host, rhesus macaques (Macaca mulatta). To determine whether this non-human primate model would be useful to assess vaccine strategies for HCMV, host immune responses to RhCMV glycoprotein B (gB) were evaluated in RhCMV-infected monkeys. Total protein extracts were prepared from cells transiently transfected with an expression plasmid for either the full-length gB or a derivative (gBΔ, 1–680 aa) lacking both the transmembrane domain and cytoplasmic tail. Western blot analysis showed identical reactivity of macaque sera with full-length gB and its derivative gBΔ, indicating that the immunodominant epitopes of gB are contained in the extracellular portion of the protein. Using gBΔ extract as a solid phase, a sensitive and specific ELISA was established to characterize gB antibody responses in monkeys acutely and chronically infected with RhCMV. During primary infection (seroconversion), gB-specific antibodies developed concurrently and in parallel with total RhCMV-specific antibodies. However, during chronic infection gB-specific antibody responses were variable. A strong correlation was observed between neutralizing and gB-specific antibody levels in RhCMV-seropositive monkeys. Taken together, the results of this study indicate that, similar to host humoral responses to HCMV gB, anti-gB antibodies are an integral part of humoral immunity to RhCMV infection and probably play an important protective role in limiting the extent of RhCMV infection. Thus, the rhesus macaque model of HCMV infection is relevant for testing gB-based immune therapies.

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Induction of Potent Immune Responses by Cationic Microparticles with Adsorbed Human Immunodeficiency Virus DNA Vaccines

Journal of Virology ◽

10.1128/jvi.75.19.9037-9043.2001 ◽

2001 ◽

Vol 75 (19) ◽

pp. 9037-9043 ◽

Cited By ~ 141

Author(s):

Derek O'Hagan ◽

Manmohan Singh ◽

Mildred Ugozzoli ◽

Carl Wild ◽

Susan Barnett ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Immune Responses ◽

Guinea Pigs ◽

Dna Vaccines ◽

Rhesus Macaques ◽

Antibody Responses ◽

Combination Vaccine ◽

Enzyme Linked Immunosorbent Assay ◽

Naked Dna ◽

Immunodeficiency Virus

ABSTRACT The effectiveness of cationic microparticles with adsorbed DNA at inducing immune responses was investigated in mice, guinea pigs, and rhesus macaques. Plasmid DNA vaccines encoding human immunodeficiency virus (HIV) Gag and Env adsorbed onto the surface of cationic poly(lactide-coglycolide) (PLG) microparticles were shown to be substantially more potent than corresponding naked DNA vaccines. In mice immunized with HIV gag DNA, adsorption onto PLG increased CD8+ T-cell and antibody responses by ∼100- and ∼1,000-fold, respectively. In guinea pigs immunized with HIV env DNA adsorbed onto PLG, antibody responses showed a more rapid onset and achieved markedly higher enzyme-linked immunosorbent assay and neutralizing titers than in animals immunized with naked DNA. Further enhancement of antibody responses was observed in animals vaccinated with PLG/DNA microparticles formulated with aluminum phosphate. The magnitude of anti-Env antibody responses induced by PLG/DNA particles was equivalent to that induced by recombinant gp120 protein formulated with a strong adjuvant, MF-59. In guinea pigs immunized with a combination vaccine containing HIVenv and HIV gag DNA plasmids on PLG microparticles, substantially superior antibody responses were induced against both components, as measured by onset, duration, and titer. Furthermore, PLG formulation overcame an apparent hyporesponsiveness of the env DNA component in the combination vaccine. Finally, preliminary data in rhesus macaques demonstrated a substantial enhancement of immune responses afforded by PLG/DNA. Therefore, formulation of DNA vaccines by adsorption onto PLG microparticles is a powerful means of increasing vaccine potency.

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Optimization of Non-Coding Regions Improves Protective Efficacy of an mRNA SARS-CoV-2 Vaccine in Nonhuman Primates

10.1101/2021.08.13.456316 ◽

2021 ◽

Author(s):

Makda Gebre ◽

Susanne Rauch ◽

Nicole Roth ◽

Jingyou Yu ◽

Abishek Chandrashekar ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Nonhuman Primates ◽

Protective Efficacy ◽

Neutralizing Antibody ◽

Antigen Expression ◽

Antibody Responses ◽

Partial Protection ◽

Viral Loads ◽

Coding Regions ◽

Cell Responses

The CVnCoV (CureVac) mRNA vaccine for SARS-CoV-2 has recently been evaluated in a phase 2b/3 efficacy trial in humans. CV2CoV is a second-generation mRNA vaccine with optimized non-coding regions and enhanced antigen expression. Here we report a head-to-head study of the immunogenicity and protective efficacy of CVnCoV and CV2CoV in nonhuman primates. We immunized 18 cynomolgus macaques with two doses of 12 ug of lipid nanoparticle formulated CVnCoV, CV2CoV, or sham (N=6/group). CV2CoV induced substantially higher binding and neutralizing antibodies, memory B cell responses, and T cell responses as compared with CVnCoV. CV2CoV also induced more potent neutralizing antibody responses against SARS-CoV-2 variants, including B.1.351 (beta), B.1.617.2 (delta), and C.37 (lambda). While CVnCoV provided partial protection against SARS-CoV-2 challenge, CV2CoV afforded robust protection with markedly lower viral loads in the upper and lower respiratory tract. Antibody responses correlated with protective efficacy. These data demonstrate that optimization of non-coding regions can greatly improve the immunogenicity and protective efficacy of an mRNA SARS-CoV-2 vaccine in nonhuman primates.

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Intradermal-delivered DNA vaccine provides anamnestic protection in a rhesus macaque SARS-CoV-2 challenge model

10.1101/2020.07.28.225649 ◽

2020 ◽

Cited By ~ 12

Author(s):

Ami Patel ◽

Jewell Walters ◽

Emma L. Reuschel ◽

Katherine Schultheis ◽

Elizabeth Parzych ◽

...

Keyword(s):

Dna Vaccine ◽

Protective Efficacy ◽

Rhesus Macaques ◽

Adaptive Immune System ◽

Neutralizing Antibody ◽

Antibody Responses ◽

Viral Loads ◽

Cell Responses ◽

Adaptive Immune ◽

Nasal Clearance

SummaryCoronavirus disease 2019 (COVID-19), caused by the SARS-CoV-2 virus, has had a dramatic global impact on public health, social, and economic infrastructures. Here, we assess immunogenicity and anamnestic protective efficacy in rhesus macaques of the intradermal (ID)-delivered SARS-CoV-2 spike DNA vaccine, INO-4800. INO-4800 is an ID-delivered DNA vaccine currently being evaluated in clinical trials. Vaccination with INO-4800 induced T cell responses and neutralizing antibody responses against both the D614 and G614 SARS-CoV-2 spike proteins. Several months after vaccination, animals were challenged with SARS-CoV-2 resulting in rapid recall of anti-SARS-CoV-2 spike protein T and B cell responses. These responses were associated with lower viral loads in the lung and with faster nasal clearance of virus. These studies support the immune impact of INO-4800 for inducing both humoral and cellular arms of the adaptive immune system which are likely important for providing durable protection against COVID-19 disease.

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Protective Efficacy of Gastrointestinal SARS-CoV-2 Delivery Against Intranasal and Intratracheal SARS-CoV-2 Challenge in Rhesus Macaques

10.1101/2021.09.13.460191 ◽

2021 ◽

Author(s):

Jingyou Yu ◽

Natalie Collins ◽

Noe Bladimir Mercado ◽

Katherine McMahan ◽

Abishek Chandrashekar ◽

...

Keyword(s):

Gastrointestinal Tract ◽

Bronchoalveolar Lavage ◽

Neutralizing Antibodies ◽

Protective Efficacy ◽

Rhesus Macaques ◽

Oral Vaccine ◽

Viral Loads ◽

Mucosal Antibody ◽

Nasal Swabs ◽

Live Oral Vaccine

Live oral vaccines have been explored for their protective efficacy against respiratory viruses, particularly for adenovirus serotypes 4 and 7. The potential of a live oral vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), however, remains unclear. In this study, we assessed the immunogenicity of live SARS-CoV-2 delivered to the gastrointestinal tract in rhesus macaques and its protective efficacy against intranasal and intratracheal SARS-CoV-2 challenge. Post-pyloric administration of SARS-CoV-2 by esophagogastroduodenoscopy resulted in limited virus replication in the gastrointestinal tract and minimal to no induction of mucosal antibody titers in rectal swabs, nasal swabs, and bronchoalveolar lavage. Low levels of serum neutralizing antibodies were induced and correlated with modestly diminished viral loads in nasal swabs and bronchoalveolar lavage following intranasal and intratracheal SARS-CoV-2 challenge. Overall, our data show that post-pyloric inoculation of live SARS-CoV-2 is weakly immunogenic and confers partial protection against respiratory SARS-CoV-2 challenge in rhesus macaques.

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Exploitation of Interleukin-10 (IL-10) Signaling Pathways: Alternate Roles of Viral and Cellular IL-10 in Rhesus Cytomegalovirus Infection

Journal of Virology ◽

10.1128/jvi.00635-16 ◽

2016 ◽

Vol 90 (21) ◽

pp. 9920-9930 ◽

Cited By ~ 10

Author(s):

Meghan K. Eberhardt ◽

Ashlesha Deshpande ◽

Joseph Fike ◽

Rebecca Short ◽

Kimberli A. Schmidt ◽

...

Keyword(s):

Dendritic Cells ◽

Immune Responses ◽

Peripheral Blood Mononuclear Cells ◽

Mononuclear Cells ◽

Rhesus Macaques ◽

Interleukin 10 ◽

Peripheral Blood Mononuclear ◽

Blood Mononuclear Cells ◽

Rhesus Cytomegalovirus

ABSTRACT There is accumulating evidence that the viral interleukin-10 (vIL-10) ortholog of both human and rhesus cytomegalovirus (HCMV and RhCMV, respectively) suppresses the functionality of cell types that are critical to contain virus dissemination and help shape long-term immunity during the earliest virus-host interactions. In particular, exposure of macrophages, peripheral blood mononuclear cells, monocyte-derived dendritic cells, and plasmacytoid dendritic cells to vIL-10 suppresses multiple effector functions including, notably, those that link innate and adaptive immune responses. Further, vaccination of RhCMV-uninfected rhesus macaques with nonfunctional forms of RhCMV vIL-10 greatly restricted parameters of RhCMV infection following RhCMV challenge of the vaccinees. Vaccinees exhibited significantly reduced shedding of RhCMV in saliva and urine following RhCMV challenge compared to shedding in unvaccinated controls. Based on the evidence that vIL-10 is critical during acute infection, the role of vIL-10 during persistent infection was analyzed in rhesus macaques infected long term with RhCMV to determine whether postinfection vaccination against vIL-10 could change the virus-host balance. RhCMV-seropositive macaques, which shed RhCMV in saliva, were vaccinated with nonfunctional RhCMV vIL-10, and shedding levels of RhCMV in saliva were evaluated. Following robust increases in vIL-10-binding and vIL-10-neutralizing antibodies, shedding levels of RhCMV modestly declined, consistent with the interpretation that vIL-10 may play a functional role during persistent infection. However, a more significant association was observed between the levels of cellular IL-10 secreted in peripheral blood mononuclear cells exposed to RhCMV antigens and shedding of RhCMV in saliva. This result implies that RhCMV persistence is associated with the induction of cellular IL-10 receptor-mediated signaling pathways. IMPORTANCE Human health is adversely impacted by viruses that establish lifelong infections that are often accompanied with increased morbidity and mortality (e.g., infections with HIV, hepatitis C virus, or human cytomegalovirus). A longstanding but unfulfilled goal has been to develop postinfection vaccine strategies that could “reboot” the immune system of an infected individual in ways that would enable the infected host to develop immune responses that clear reservoirs of persistent virus infection, effectively curing the host of infection. This concept was evaluated in rhesus macaques infected long term with rhesus cytomegalovirus by repeatedly immunizing infected animals with nonfunctional versions of the rhesus cytomegalovirus-encoded viral interleukin-10 immune-modulating protein. Following vaccine-mediated boosting of antibody titers to viral interleukin-10, there was modest evidence for increased immunological control of the virus following vaccination. More significantly, data were also obtained that indicated that rhesus cytomegalovirus is able to persist due to upregulation of the cellular interleukin-10 signaling pathway.

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