1
|
Kayesh MEH, Kohara M, Tsukiyama-Kohara K. Recent Insights into the Molecular Mechanisms of the Toll-like Receptor Response to Influenza Virus Infection. Int J Mol Sci 2024; 25:5909. [PMID: 38892096 PMCID: PMC11172706 DOI: 10.3390/ijms25115909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2024] [Revised: 05/23/2024] [Accepted: 05/26/2024] [Indexed: 06/21/2024] Open
Abstract
Influenza A viruses (IAVs) pose a significant global threat to human health. A tightly controlled host immune response is critical to avoid any detrimental effects of IAV infection. It is critical to investigate the association between the response of Toll-like receptors (TLRs) and influenza virus. Because TLRs may act as a double-edged sword, a balanced TLR response is critical for the overall benefit of the host. Consequently, a thorough understanding of the TLR response is essential for targeting TLRs as a novel therapeutic and prophylactic intervention. To date, a limited number of studies have assessed TLR and IAV interactions. Therefore, further research on TLR interactions in IAV infection should be conducted to determine their role in host-virus interactions in disease causation or clearance of the virus. Although influenza virus vaccines are available, they have limited efficacy, which should be enhanced to improve their efficacy. In this study, we discuss the current status of our understanding of the TLR response in IAV infection and the strategies adopted by IAVs to avoid TLR-mediated immune surveillance, which may help in devising new therapeutic or preventive strategies. Furthermore, recent advances in the use of TLR agonists as vaccine adjuvants to enhance influenza vaccine efficacy are discussed.
Collapse
Affiliation(s)
- Mohammad Enamul Hoque Kayesh
- Department of Microbiology and Public Health, Faculty of Animal Science and Veterinary Medicine, Patuakhali Science and Technology University, Barishal 8210, Bangladesh
| | - Michinori Kohara
- Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan;
| | - Kyoko Tsukiyama-Kohara
- Transboundary Animal Diseases Centre, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima 890-0065, Japan
| |
Collapse
|
2
|
Holbrook BC, Clemens EA, Alexander-Miller MA. Sex-Dependent Effects on Influenza-Specific Antibody Quantity and Neutralizing Activity following Vaccination of Newborn Non-Human Primates Is Determined by Adjuvants. Vaccines (Basel) 2024; 12:415. [PMID: 38675797 PMCID: PMC11054256 DOI: 10.3390/vaccines12040415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 04/08/2024] [Accepted: 04/11/2024] [Indexed: 04/28/2024] Open
Abstract
A number of studies have demonstrated the role of sex in regulating immune responses to vaccination. However, these findings have been limited to adults for both human and animal models. As a result, our understanding of the impact of sex on vaccine responses in the newborn is highly limited. Here, we probe this important question using a newborn non-human primate model. We leveraged our prior analysis of two cohorts of newborns, with one being mother-reared and one nursery-reared. This provided adequate numbers of males and females to interrogate the impact of sex on the response to inactivated influenza vaccines alone or adjuvanted with R848, flagellin, or both. We found that, in contrast to what has been reported in adults, the non-adjuvanted inactivated influenza virus vaccine induced similar levels of virus-specific IgG in male and female newborns. However, the inclusion of R848, either alone or in combination with flagellin, resulted in higher antibody titers in females compared to males. Sex-specific increases in the neutralizing antibody were only observed when both R848 and flagellin were present. These data, generated in the highly translational NHP newborn model, provide novel insights into the role of sex in the immune response of newborns.
Collapse
Affiliation(s)
| | | | - Martha A. Alexander-Miller
- Department of Microbiology and Immunology, Wake Forest University School of Medicine, Rm 2E-018 Biotech Place, 575 North Patterson Ave., Winston-Salem, NC 27101, USA; (B.C.H.); elene.a.- (E.A.C.)
| |
Collapse
|
3
|
Crofts KF, Page CL, Swedik SM, Holbrook BC, Meyers AK, Zhu X, Parsonage D, Westcott MM, Alexander-Miller MA. An Analysis of Linker-Dependent Effects on the APC Activation and In Vivo Immunogenicity of an R848-Conjugated Influenza Vaccine. Vaccines (Basel) 2023; 11:1261. [PMID: 37515076 PMCID: PMC10383912 DOI: 10.3390/vaccines11071261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 07/10/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
Subunit or inactivated vaccines comprise the majority of vaccines used against viral and bacterial pathogens. However, compared to their live/attenuated counterparts, these vaccines often demonstrate reduced immunogenicity, requiring multiple boosters and or adjuvants to elicit protective immune responses. For this reason, studies of adjuvants and the mechanism through which they can improve inactivated vaccine responses are critical for the development of vaccines with increased efficacy. Studies have shown that the direct conjugation of adjuvant to antigen promotes vaccine immunogenicity, with the advantage of both the adjuvant and antigen targeting the same cell. Using this strategy of direct linkage, we developed an inactivated influenza A (IAV) vaccine that is directly conjugated with the Toll-like receptor 7/8 agonist resiquimod (R848) through a heterobifunctional crosslinker. Previously, we showed that this vaccine resulted in improved protection and viral clearance in newborn nonhuman primates compared to a non-adjuvanted vaccine. We subsequently discovered that the choice of linker used to conjugate R848 to the virus alters the stimulatory activity of the vaccine, promoting increased maturation and proinflammatory cytokine production from DC differentiated in vitro. With this knowledge, we explored how the choice of crosslinker impacts the stimulatory activity of these vaccines. We found that the linker choice alters signaling through the NF-κB pathway in human monocyte-derived dendritic cells (moDCs). Further, we extended our analyses to in vivo differentiated APC present in human peripheral blood, replicating the linker-dependent differences found in in vitro differentiated cells. Finally, we demonstrated in a mouse model that the choice of linker impacts the amount of IAV-specific IgG antibody produced in response to vaccination. These data enhance our understanding of conjugation approaches for improving vaccine immunogenicity.
Collapse
Affiliation(s)
- Kali F. Crofts
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA; (K.F.C.); (C.L.P.); (S.M.S.); (B.C.H.); (A.K.M.); (X.Z.); (M.M.W.)
| | - Courtney L. Page
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA; (K.F.C.); (C.L.P.); (S.M.S.); (B.C.H.); (A.K.M.); (X.Z.); (M.M.W.)
| | - Stephanie M. Swedik
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA; (K.F.C.); (C.L.P.); (S.M.S.); (B.C.H.); (A.K.M.); (X.Z.); (M.M.W.)
| | - Beth C. Holbrook
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA; (K.F.C.); (C.L.P.); (S.M.S.); (B.C.H.); (A.K.M.); (X.Z.); (M.M.W.)
| | - Allison K. Meyers
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA; (K.F.C.); (C.L.P.); (S.M.S.); (B.C.H.); (A.K.M.); (X.Z.); (M.M.W.)
| | - Xuewei Zhu
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA; (K.F.C.); (C.L.P.); (S.M.S.); (B.C.H.); (A.K.M.); (X.Z.); (M.M.W.)
- Department of Internal Medicine, Section on Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA
| | - Derek Parsonage
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA;
| | - Marlena M. Westcott
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA; (K.F.C.); (C.L.P.); (S.M.S.); (B.C.H.); (A.K.M.); (X.Z.); (M.M.W.)
| | - Martha A. Alexander-Miller
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA; (K.F.C.); (C.L.P.); (S.M.S.); (B.C.H.); (A.K.M.); (X.Z.); (M.M.W.)
| |
Collapse
|
4
|
TLR agonists induce sustained IgG to hemagglutinin stem and modulate T cells following newborn vaccination. NPJ Vaccines 2022; 7:102. [PMID: 36038596 PMCID: PMC9424286 DOI: 10.1038/s41541-022-00523-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 08/05/2022] [Indexed: 11/08/2022] Open
Abstract
The newborn immune system is characterized by diminished immune responses that leave infants vulnerable to virus-mediated disease and make vaccination more challenging. Optimal vaccination strategies for influenza A virus (IAV) in newborns should result in robust levels of protective antibodies, including those with broad reactivity to combat the variability in IAV strains across seasons. The stem region of the hemagglutinin (HA) molecule is a target of such antibodies. Using a nonhuman primate model, we investigate the capacity of newborns to generate and maintain antibodies to the conserved stem region following vaccination. We find adjuvanting an inactivated vaccine with the TLR7/8 agonist R848 is effective in promoting sustained HA stem-specific IgG. Unexpectedly, HA stem-specific antibodies were generated with a distinct kinetic pattern compared to the overall response. Administration of R848 was associated with increased influenza-specific T follicular helper cells as well as Tregs with a less suppressive phenotype, suggesting adjuvant impacts multiple cell types that have the potential to contribute to the HA-stem response.
Collapse
|
5
|
Zhuang X, Chen L, Yang S, Xia S, Xu Z, Zhang T, Zeng B, Yu T, Yu N, Wang W, Lu H, Tian M, Jin N. R848 Adjuvant Laden With Self-Assembled Nanoparticle-Based mRNA Vaccine Elicits Protective Immunity Against H5N1 in Mice. Front Immunol 2022; 13:836274. [PMID: 35711431 PMCID: PMC9197463 DOI: 10.3389/fimmu.2022.836274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 05/03/2022] [Indexed: 11/13/2022] Open
Abstract
In order to perfect the design strategy of messenger RNA (mRNA) vaccines against the H5N1 influenza virus, we investigated whether different antigen designs and the use of adjuvants could improve the immune effect of mRNA vaccines. We designed three different forms of antigen genes, including Flu [H1/H3/H5/B-HA2(aa90~105)-M2e(24aa)], Flu-Fe (Fe, ferritin), and CD5-Flu-Fe (CD5, a secretion signal peptide). Meanwhile, R848 (Requimod) was selected as the adjuvant of the mRNA vaccine. We prepared cationic lipid nanoparticles for mRNA delivery, named LNP-Man (mannose-modified lipid nanoparticles). Cell transfection results showed that Flu-Fe/CD5-Flu-Fe containing ferritin could express the target antigens HA2 and M2e more efficiently than Flu. In the mice immune experiment, five immune groups (LNP-Man/Flu, LNP-Man/Flu-Fe, LNP-Man/CD5-Flu-Fe, LNP-Man/Flu-Fe+R848, and LNP-Man/CD5-Flu-Fe+R848) and two control groups (LNP-Man, PBS) were set up. After being infected with the 1×LD50 H5N1 avian influenza virus, the survival rate of the mice in the LNP-Man/CD5-Flu-Fe, LNP-Man/Flu-Fe+R848, and LNP-Man/CD5-Flu-Fe+R848 were 100%. More importantly, in LNP-Man/Flu-Fe+R848 and LNP-Man/CD5-Flu-Fe+R848 groups, there was no residual virus detected in the mice lung tissue on the 5th day postchallenge. Overall, this study provides a new idea for the design of H5N1 avian influenza virus mRNA vaccines in terms of antigen designs and adjuvant selection.
Collapse
Affiliation(s)
- Xinyu Zhuang
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Luer Chen
- College of Veterinary Medicine, Jilin University, Changchun, China
| | - Songhui Yang
- College of Agriculture, Yanbian University, Agricultural College of Yanbian University, Yanji, China
| | - Shengnan Xia
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
| | - Zhiqiang Xu
- College of Agriculture, Yanbian University, Agricultural College of Yanbian University, Yanji, China
| | - Tong Zhang
- College of Veterinary Medicine, Jilin University, Changchun, China
| | - Boyu Zeng
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
| | - Tong Yu
- College of Veterinary Medicine, Jilin Agricultural University, Changchun, China
| | - Ning Yu
- College of Veterinary Medicine, Jilin University, Changchun, China
| | - Wei Wang
- College of Animal Science and Technology, Guangxi University, Nanning, China
- Institute of Virology, Wenzhou University, Wenzhou, China
| | - Huijun Lu
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
- Institute of Virology, Wenzhou University, Wenzhou, China
| | - Mingyao Tian
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Ningyi Jin
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
- College of Veterinary Medicine, Jilin University, Changchun, China
| |
Collapse
|
6
|
Crofts KF, Holbrook BC, D’Agostino RB, Alexander-Miller MA. Analysis of R848 as an Adjuvant to Improve Inactivated Influenza Vaccine Immunogenicity in Elderly Nonhuman Primates. Vaccines (Basel) 2022; 10:vaccines10040494. [PMID: 35455242 PMCID: PMC9032612 DOI: 10.3390/vaccines10040494] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/10/2022] [Accepted: 03/17/2022] [Indexed: 01/13/2023] Open
Abstract
Elderly individuals are highly susceptible to developing severe outcomes as a result of influenza A virus (IAV) infection. This can be attributed to alterations that span the aged immune system, which also result in reduced responsiveness to the seasonal inactivated vaccine. Given the rapidly increasing number of individuals in this age group, it is imperative that we develop strategies that can better protect this population from IAV-associated disease. Based on our previous findings that the TLR7/8 agonist resiquimod (R848) could efficiently boost responses in the newborn, another population with decreased vaccine responsiveness, we evaluated this adjuvant in an elderly African green monkey (AGM) model. AGM aged 16-24 years old (equivalent to 64-96 in human years) were primed and boosted with inactivated A/PuertoRico/8/1934 (H1N1) (IPR8) alone or directly linked to R848 (IPR8-R848). We observed increases in the level of circulating virus-specific IgM antibody 10 days following primary vaccination in AGM that were vaccinated with IPR8-R848, but not IPR8 alone. In addition, there were significant increases in virus-specific IgG after boosting selectively in the IPR8-R848 vaccinated animals. These findings provide insights into the ability of R848 to modulate the aged immune system in the context of IAV vaccination.
Collapse
Affiliation(s)
- Kali F. Crofts
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA; (K.F.C.); (B.C.H.)
| | - Beth C. Holbrook
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA; (K.F.C.); (B.C.H.)
| | - Ralph B. D’Agostino
- Department of Biostatistical Sciences, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA;
| | - Martha A. Alexander-Miller
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA; (K.F.C.); (B.C.H.)
- Correspondence:
| |
Collapse
|
7
|
Berendam SJ, Morgan-Asiedu PK, Mangan RJ, Li SH, Heimsath H, Luo K, Curtis AD, Eudailey JA, Fox CB, Tomai MA, Phillips B, Itell HL, Kunz E, Hudgens M, Cronin K, Wiehe K, Alam SM, Van Rompay KKA, De Paris K, Permar SR, Moody MA, Fouda GG. Different adjuvanted pediatric HIV envelope vaccines induced distinct plasma antibody responses despite similar B cell receptor repertoires in infant rhesus macaques. PLoS One 2022; 16:e0256885. [PMID: 34972105 PMCID: PMC8719683 DOI: 10.1371/journal.pone.0256885] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 12/09/2021] [Indexed: 11/25/2022] Open
Abstract
Different HIV vaccine regimens elicit distinct plasma antibody responses in both human and nonhuman primate models. Previous studies in human and non-human primate infants showed that adjuvants influenced the quality of plasma antibody responses induced by pediatric HIV envelope vaccine regimens. We recently reported that use of the 3M052-SE adjuvant and longer intervals between vaccinations are associated with higher magnitude of antibody responses in infant rhesus macaques. However, the impact of different adjuvants in HIV vaccine regimens on the developing infant B cell receptor (BCR) repertoire has not been studied. This study evaluated whether pediatric HIV envelope vaccine regimens with different adjuvants induced distinct antigen-specific memory B cell repertoires and whether specific immunoglobulin (Ig) immunogenetic characteristics are associated with higher magnitude of plasma antibody responses in vaccinated infant rhesus macaques. We utilized archived preclinical pediatric HIV vaccine studies PBMCs and tissue samples from 19 infant rhesus macaques immunized either with (i) HIV Env protein with a squalene adjuvant, (ii) MVA-HIV and Env protein co-administered using a 3-week interval, (iii) MVA-HIV prime/ protein boost with an extended 6-week interval between immunizations, or (iv) with HIV Env administered with 3M-052-SE adjuvant. Frequencies of vaccine-elicited HIV Env-specific memory B cells from PBMCs and tissues were similar across vaccination groups (frequency range of 0.06–1.72%). There was no association between vaccine-elicited antigen-specific memory B cell frequencies and plasma antibody titer or avidity. Moreover, the epitope specificity and Ig immunogenetic features of vaccine-elicited monoclonal antibodies did not differ between the different vaccine regimens. These data suggest that pediatric HIV envelope vaccine candidates with different adjuvants that previously induced higher magnitude and quality of plasma antibody responses in infant rhesus macaques were not driven by distinct antigen-specific memory BCR repertoires.
Collapse
Affiliation(s)
- Stella J. Berendam
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Papa K. Morgan-Asiedu
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Riley J. Mangan
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Shuk Hang Li
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Holly Heimsath
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Kan Luo
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Alan D. Curtis
- Department of Microbiology and Immunology, Children’s Research Institute and Center for AIDS Research, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Joshua A. Eudailey
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Pediatrics, Weill Cornell College of Medicine, New York City, New York, United States of America
| | - Christopher B. Fox
- Infectious Disease Research Institute (IDRI), Seattle, Washington State, United States of America
- Department of Global Health, University of Washington, Seattle, Washington State, United States of America
| | - Mark A. Tomai
- 3M Center, 3 M Drug Delivery Systems, St. Paul, Minnesota, United States of America
| | - Bonnie Phillips
- Department of Microbiology and Immunology, Children’s Research Institute and Center for AIDS Research, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Hannah L. Itell
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Erika Kunz
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Michael Hudgens
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Kenneth Cronin
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Kevin Wiehe
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - S. Munir Alam
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Koen K. A. Van Rompay
- California National Primate Research Center, University of California at Davis, Davis, California, United States of America
| | - Kristina De Paris
- Department of Microbiology and Immunology, Children’s Research Institute and Center for AIDS Research, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Sallie R. Permar
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Pediatrics, Weill Cornell College of Medicine, New York City, New York, United States of America
| | - M. Anthony Moody
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Genevieve G. Fouda
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail:
| |
Collapse
|
8
|
Wirsching S, Machtakova M, Borgans F, Pretsch L, Fichter M, Cacicedo ML, Thérien-Aubin H, Landfester K, Gehring S. OVA-PEG-R848 nanocapsules stimulate neonatal conventional and plasmacytoid dendritic cells. Front Pediatr 2022; 10:966113. [PMID: 36177449 PMCID: PMC9513203 DOI: 10.3389/fped.2022.966113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 08/17/2022] [Indexed: 12/04/2022] Open
Abstract
Childhood mortality represents a major issue with 5. 3 million worldwide deaths of children under 5 years of age in 2019. Approximately half of those deaths can be attributed to easily preventable, infectious diseases. Currently approved neonatal vaccines are typically effective only after multiple doses leaving infants especially vulnerable during the first 6 months of life. Survival rates could be improved significantly by developing new and more potent vaccines that are capable of overcoming inherently tolerogenic neonatal immune systems. TLR agonists have garnered a great deal of attention in recent years due to their extensive capacities to activate innate immunity. Herein, the superior capacity of the TLR7/8 agonist, resiquimod (R848), to activate adult and neonatal primary peripheral blood dendritic cells is demonstrated. Moreover, R848 can be conjugated to polyethylene glycol and encapsulated in ovalbumin nanocapsules to efficiently co-deliver antigen and adjuvant in vitro. This study is among the first to demonstrate the capacity of encapsulated R848 to activate neonatal dendritic cells. These findings support the potential incorporation of R848 as adjuvant in neonatal vaccines, making them more effective in eliciting a robust immune response.
Collapse
Affiliation(s)
- Sebastian Wirsching
- Children's Hospital, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | | | - Frauke Borgans
- Children's Hospital, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.,Department of Infectious Diseases, University Hospital Frankfurt, Frankfurt, Germany
| | - Leah Pretsch
- Children's Hospital, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Michael Fichter
- Children's Hospital, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.,Max Planck Institute for Polymer Research, Mainz, Germany.,Department of Dermatology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Maximiliano L Cacicedo
- Children's Hospital, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Héloïse Thérien-Aubin
- Max Planck Institute for Polymer Research, Mainz, Germany.,Department of Chemistry, Memorial University of Newfoundland, St. John's, NL, Canada
| | | | - Stephan Gehring
- Children's Hospital, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| |
Collapse
|
9
|
Bhagchandani S, Johnson JA, Irvine DJ. Evolution of Toll-like receptor 7/8 agonist therapeutics and their delivery approaches: From antiviral formulations to vaccine adjuvants. Adv Drug Deliv Rev 2021; 175:113803. [PMID: 34058283 PMCID: PMC9003539 DOI: 10.1016/j.addr.2021.05.013] [Citation(s) in RCA: 70] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 05/04/2021] [Accepted: 05/15/2021] [Indexed: 02/07/2023]
Abstract
Imidazoquinoline derivatives (IMDs) and related compounds function as synthetic agonists of Toll-like receptors 7 and 8 (TLR7/8) and one is FDA approved for topical antiviral and skin cancer treatments. Nevertheless, these innate immune system-activating drugs have potentially much broader therapeutic utility; they have been pursued as antitumor immunomodulatory agents and more recently as candidate vaccine adjuvants for cancer and infectious disease. The broad expression profiles of TLR7/8, poor pharmacokinetic properties of IMDs, and toxicities associated with systemic administration, however, are formidable barriers to successful clinical translation. Herein, we review IMD formulations that have advanced to the clinic and discuss issues related to biodistribution and toxicity that have hampered the further development of these compounds. Recent strategies aimed at enhancing safety and efficacy, particularly through the use of bioconjugates and nanoparticle formulations that alter pharmacokinetics, biodistribution, and cellular targeting, are described. Finally, key aspects of the biology of TLR7 signaling, such as TLR7 tolerance, that may need to be considered in the development of new IMD therapeutics are discussed.
Collapse
Affiliation(s)
- Sachin Bhagchandani
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA 02139, USA
| | - Jeremiah A Johnson
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA.
| | - Darrell J Irvine
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA; Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA 02139, USA.
| |
Collapse
|
10
|
Clemens EA, Holbrook BC, Kanekiyo M, Yewdell JW, Graham BS, Alexander-Miller MA. An R848-Conjugated Influenza Virus Vaccine Elicits Robust Immunoglobulin G to Hemagglutinin Stem in a Newborn Nonhuman Primate Model. J Infect Dis 2021; 224:351-359. [PMID: 33245745 PMCID: PMC8280492 DOI: 10.1093/infdis/jiaa728] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 11/20/2020] [Indexed: 12/19/2022] Open
Abstract
Eliciting broadly protective antibodies is a critical goal for the development of more effective vaccines against influenza. Optimizing protection is of particular importance in newborns, who are highly vulnerable to severe disease following infection. An effective vaccination strategy for this population must surmount the challenges associated with the neonatal immune system as well as mitigate the inherent immune subdominance of conserved influenza virus epitopes, responses to which can provide broader protection. Here, we show that prime-boost vaccination with a TLR7/8 agonist (R848)-conjugated influenza A virus vaccine elicits antibody responses to the highly conserved hemagglutinin stem and promotes rapid induction of virus neutralizing stem-specific antibodies following viral challenge. These findings support the efficacy of R848 as an effective adjuvant for newborns and demonstrate its ability to enhance antibody responses to subdominant antigenic sites in this at-risk population.
Collapse
Affiliation(s)
- Elene A Clemens
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Beth C Holbrook
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Masaru Kanekiyo
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Jonathan W Yewdell
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Barney S Graham
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Martha A Alexander-Miller
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| |
Collapse
|
11
|
Animal Models Utilized for the Development of Influenza Virus Vaccines. Vaccines (Basel) 2021; 9:vaccines9070787. [PMID: 34358203 PMCID: PMC8310120 DOI: 10.3390/vaccines9070787] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 07/08/2021] [Accepted: 07/10/2021] [Indexed: 12/25/2022] Open
Abstract
Animal models have been an important tool for the development of influenza virus vaccines since the 1940s. Over the past 80 years, influenza virus vaccines have evolved into more complex formulations, including trivalent and quadrivalent inactivated vaccines, live-attenuated vaccines, and subunit vaccines. However, annual effectiveness data shows that current vaccines have varying levels of protection that range between 40–60% and must be reformulated every few years to combat antigenic drift. To address these issues, novel influenza virus vaccines are currently in development. These vaccines rely heavily on animal models to determine efficacy and immunogenicity. In this review, we describe seasonal and novel influenza virus vaccines and highlight important animal models used to develop them.
Collapse
|
12
|
Kaushik D, Kaur A, Petrovsky N, Salunke DB. Structural evolution of toll-like receptor 7/8 agonists from imidazoquinolines to imidazoles. RSC Med Chem 2021; 12:1065-1120. [PMID: 34355178 DOI: 10.1039/d1md00031d] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 04/27/2021] [Indexed: 12/11/2022] Open
Abstract
Several synthetic heterocyclic small molecules like imiquimod, resiquimod, CL097, CL075, bromopirone, tilorone, loxoribine and isatoribine demonstrated TLR7/8 agonistic activity and relatively modest structural changes in such molecules result in major variation in the TLR7 and/or TLR8 activity. A strict dependency of the electronic configuration of the heterocyclic system was also observed to influence the agonistic activity. In the present review, an evolution of imidazole based TLR7/8 agonist from imidazoquinoline based scaffold is delineated along with the elaboration of detailed structure activity relationship (SAR) in each chemotype. The structural and activity details of not only the active compounds but also the related inactive compounds are included to better understand the SAR. TLR7/8 agonists are emerging as promising vaccine adjuvant candidates and the present SAR and structural information will provide a road map towards the identification of more potent and appropriate candidates for further drug discovery.
Collapse
Affiliation(s)
- Deepender Kaushik
- Department of Chemistry and Centre of Advanced Studies in Chemistry, Panjab University Chandigarh 160014 India
| | - Arshpreet Kaur
- Department of Chemistry and Centre of Advanced Studies in Chemistry, Panjab University Chandigarh 160014 India
| | - Nikolai Petrovsky
- Vaxine Pty Ltd 11 Walkley Avenue Warradale 5046 Australia.,College of Medicine and Public Health, Flinders University Bedford Park 5042 Australia
| | - Deepak B Salunke
- Department of Chemistry and Centre of Advanced Studies in Chemistry, Panjab University Chandigarh 160014 India .,National Interdisciplinary Centre of Vaccine, Immunotherapeutics and Antimicrobials, Panjab University Chandigarh 160014 India
| |
Collapse
|
13
|
Soon MSF, Nalubega M, Boyle MJ. T-follicular helper cells in malaria infection and roles in antibody induction. OXFORD OPEN IMMUNOLOGY 2021; 2:iqab008. [PMID: 36845571 PMCID: PMC9914587 DOI: 10.1093/oxfimm/iqab008] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/03/2021] [Accepted: 03/08/2021] [Indexed: 01/29/2023] Open
Abstract
Immunity to malaria is mediated by antibodies that block parasite replication to limit parasite burden and prevent disease. Cytophilic antibodies have been consistently shown to be associated with protection, and recent work has improved our understanding of the direct and Fc-mediated mechanisms of protective antibodies. Antibodies also have important roles in vaccine-mediated immunity. Antibody induction is driven by the specialized CD4+ T cells, T-follicular helper (Tfh) cells, which function within the germinal centre to drive B-cell activation and antibody induction. In humans, circulating Tfh cells can be identified in peripheral blood and are differentiated into subsets that appear to have pathogen/vaccination-specific roles in antibody induction. Tfh cell responses are essential for protective immunity from Plasmodium infection in murine models of malaria. Our understanding of the activation of Tfh cells during human malaria infection and the importance of different Tfh cell subsets in antibody development is still emerging. This review will discuss our current knowledge of Tfh cell activation and development in malaria, and the potential avenues and pitfalls of targeting Tfh cells to improve malaria vaccines.
Collapse
Affiliation(s)
- Megan S F Soon
- Department of Infectious Diseases, QIMR-Berghofer, 300 Herston Road, Herston, QLD, 4006, Australia
| | - Mayimuna Nalubega
- Infectious Diseases Research Collaboration, Tororo District Hospital, Tororo, Uganda
| | - Michelle J Boyle
- Department of Infectious Diseases, QIMR-Berghofer, 300 Herston Road, Herston, QLD, 4006, Australia,Correspondence address. QIMR Berghofer Medical Research Institute, Brisbane, Australia. E-mail:
| |
Collapse
|
14
|
Lirussi D, Weissmann SF, Ebensen T, Nitsche-Gloy U, Franz HBG, Guzmán CA. Cyclic Di-Adenosine Monophosphate: A Promising Adjuvant Candidate for the Development of Neonatal Vaccines. Pharmaceutics 2021; 13:pharmaceutics13020188. [PMID: 33535570 PMCID: PMC7912751 DOI: 10.3390/pharmaceutics13020188] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 01/25/2021] [Accepted: 01/26/2021] [Indexed: 12/18/2022] Open
Abstract
Underdeveloped immunity during the neonatal age makes this period one of the most dangerous during the human lifespan, with infection-related mortality being one of the highest of all age groups. It is also discussed that vaccination during this time window may result in tolerance rather than in productive immunity, thus raising concerns about the overall vaccine-mediated protective efficacy. Cyclic di-nucleotides (CDN) are bacterial second messengers that are rapidly sensed by the immune system as a danger signal, allowing the utilization of these molecules as potent activators of the immune response. We have previously shown that cyclic di-adenosine monophosphate (CDA) is a potent and versatile adjuvant capable of promoting humoral and cellular immunity. We characterize here the cytokine profiles elicited by CDA in neonatal cord blood in comparison with other promising neonatal adjuvants, such as the imidazoquinoline resiquimod (R848), which is a synthetic dual TLR7 and TLR8 agonist. We observed superior activity of CDA in eliciting T helper 1 (Th1) and T follicular helper (TfH) cytokines in cells from human cord blood when compared to R848. Additional in vivo studies in mice showed that neonatal priming in a three-dose vaccination schedule is beneficial when CDA is used as a vaccine adjuvant. Humoral antibody titers were significantly higher in mice that received a neonatal prime as compared to those that did not. This effect was absent when using other adjuvants that were reported as suitable for neonatal vaccination. The biological significance of this immune response was assessed by a challenge with a genetically modified influenza H1N1 PR8 virus. The obtained results confirmed that CDA performed better than any other adjuvant tested. Altogether, our results suggest that CDA is a potent adjuvant in vitro on human cord blood, and in vivo in newborn mice, and thus a suitable candidate for the development of neonatal vaccines.
Collapse
Affiliation(s)
- Darío Lirussi
- Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany; (S.F.W.); (C.A.G.)
- Correspondence: (D.L.); (T.E.); Tel.: +49-531-61814607 (T.E.); Fax: +49-531-618414699 (T.E.)
| | - Sebastian Felix Weissmann
- Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany; (S.F.W.); (C.A.G.)
| | - Thomas Ebensen
- Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany; (S.F.W.); (C.A.G.)
- Correspondence: (D.L.); (T.E.); Tel.: +49-531-61814607 (T.E.); Fax: +49-531-618414699 (T.E.)
| | - Ursula Nitsche-Gloy
- Women’s Clinic, Hospital Marienstift GmbH, Helmstedter Strasse 35, 38102 Braunschweig, Germany;
| | - Heiko B. G. Franz
- Department of Obstetrics and Gynecology, Women’s Clinic, Braunschweig Central Hospital, Celler Strasse 38, 38114 Braunschweig, Germany;
| | - Carlos A. Guzmán
- Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany; (S.F.W.); (C.A.G.)
| |
Collapse
|
15
|
Shultz PK, Crofts KF, Holbrook BC, Alexander-Miller MA. Neuraminidase-specific antibody responses are generated in naive and vaccinated newborn nonhuman primates following virus infection. JCI Insight 2020; 5:141655. [PMID: 33264104 PMCID: PMC7819742 DOI: 10.1172/jci.insight.141655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 11/11/2020] [Indexed: 01/30/2023] Open
Abstract
Individuals younger than 6 months of age are at significant risk from influenza virus infection; however, there is currently no vaccine approved for this age group. Influenza virus neuraminidase (NA) has emerged as a potential additional target for vaccine strategies. In this study, we sought to understand the ability of newborns to mount an antibody response to NA. Here we employed a nonhuman primate model, given the similarities to humans in immune system and development. We measured antibody to NA following infection with an H1N1 virus or following vaccination and challenge. Administration of an inactivated virus vaccine was not capable of eliciting detectable NA-specific antibody, even in the presence of adjuvants previously shown to increase total virus-specific IgG. However, both naive and vaccinated newborns generated a NA-specific antibody response following virus infection. Interestingly, the presence of the vaccine-induced response did not prevent generation of systemic antibody to NA following challenge, although the respiratory response was reduced in a significant portion of newborns. These findings are the first, to our knowledge, to evaluate the newborn response to the influenza NA protein as well as the impact of previous vaccination on generation of these antibodies following virus infection.
Collapse
|
16
|
Alexander-Miller MA. Challenges for the Newborn Following Influenza Virus Infection and Prospects for an Effective Vaccine. Front Immunol 2020; 11:568651. [PMID: 33042150 PMCID: PMC7524958 DOI: 10.3389/fimmu.2020.568651] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 08/18/2020] [Indexed: 01/10/2023] Open
Abstract
Newborns are at significantly increased risk of severe disease following infection with influenza virus. This is the collective result of their naïve status, altered immune responsiveness, and the lack of a vaccine that is effective in these individuals. Numerous studies have revealed impairments in both the innate and adaptive arms of the immune system of newborns. The consequence of these alterations is a quantitative and qualitative decrease in both antibody and T cell responses. This review summarizes the hurdles newborns experience in mounting an effective response that can clear influenza virus and limit disease following infection. In addition, the challenges, as well as the opportunities, for developing vaccines that can elicit protective responses in these at risk individuals are discussed.
Collapse
Affiliation(s)
- Martha A Alexander-Miller
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| |
Collapse
|
17
|
Challenges for the Newborn Immune Response to Respiratory Virus Infection and Vaccination. Vaccines (Basel) 2020; 8:vaccines8040558. [PMID: 32987691 PMCID: PMC7712002 DOI: 10.3390/vaccines8040558] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/19/2020] [Accepted: 09/21/2020] [Indexed: 12/14/2022] Open
Abstract
The initial months of life reflect an extremely challenging time for newborns as a naïve immune system is bombarded with a large array of pathogens, commensals, and other foreign entities. In many instances, the immune response of young infants is dampened or altered, resulting in increased susceptibility and disease following infection. This is the result of both qualitative and quantitative changes in the response of multiple cell types across the immune system. Here we provide a review of the challenges associated with the newborn response to respiratory viral pathogens as well as the hurdles and advances for vaccine-mediated protection.
Collapse
|
18
|
Rudicell RS, Garinot M, Kanekiyo M, Kamp HD, Swanson K, Chou TH, Dai S, Bedel O, Simard D, Gillespie RA, Yang K, Reardon M, Avila LZ, Besev M, Dhal PK, Dharanipragada R, Zheng L, Duan X, Dinapoli J, Vogel TU, Kleanthous H, Mascola JR, Graham BS, Haensler J, Wei CJ, Nabel GJ. Comparison of adjuvants to optimize influenza neutralizing antibody responses. Vaccine 2019; 37:6208-6220. [PMID: 31493950 DOI: 10.1016/j.vaccine.2019.08.030] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 07/26/2019] [Accepted: 08/17/2019] [Indexed: 12/14/2022]
Abstract
Seasonal influenza vaccines represent a positive intervention to limit the spread of the virus and protect public health. Yet continual influenza evolution and its ability to evade immunity pose a constant threat. For these reasons, vaccines with improved potency and breadth of protection remain an important need. We previously developed a next-generation influenza vaccine that displays the trimeric influenza hemagglutinin (HA) on a ferritin nanoparticle (NP) to optimize its presentation. Similar to other vaccines, HA-nanoparticle vaccine efficacy is increased by the inclusion of adjuvants during immunization. To identify the optimal adjuvants to enhance influenza immunity, we systematically analyzed TLR agonists for their ability to elicit immune responses. HA-NPs were compatible with nearly all adjuvants tested, including TLR2, TLR4, TLR7/8, and TLR9 agonists, squalene oil-in-water mixtures, and STING agonists. In addition, we chemically conjugated TLR7/8 and TLR9 ligands directly to the HA-ferritin nanoparticle. These TLR agonist-conjugated nanoparticles induced stronger antibody responses than nanoparticles alone, which allowed the use of a 5000-fold-lower dose of adjuvant than traditional admixtures. One candidate, the oil-in-water adjuvant AF03, was also tested in non-human primates and showed strong induction of neutralizing responses against both matched and heterologous H1N1 viruses. These data suggest that AF03, along with certain TLR agonists, enhance strong neutralizing antibody responses following influenza vaccination and may improve the breadth, potency, and ultimately vaccine protection in humans.
Collapse
Affiliation(s)
| | | | - Masaru Kanekiyo
- Vaccine Research Center, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | | | | | | | | | | | | | - Rebecca A Gillespie
- Vaccine Research Center, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | | | | | | | | | | | | | | | | | | | | | | | - John R Mascola
- Vaccine Research Center, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Barney S Graham
- Vaccine Research Center, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | | | | | | |
Collapse
|
19
|
Adjuvant-Dependent Enhancement of HIV Env-Specific Antibody Responses in Infant Rhesus Macaques. J Virol 2018; 92:JVI.01051-18. [PMID: 30089691 DOI: 10.1128/jvi.01051-18] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Accepted: 07/30/2018] [Indexed: 12/16/2022] Open
Abstract
Toward the goal of developing an effective HIV vaccine that can be administered in infancy to protect against postnatal and lifelong sexual HIV transmission risks, the current pilot study was designed to compare the effect of novel adjuvants on the induction of HIV Env-specific antibody responses in infant macaques. Aligning our studies with the adjuvanted proteins evaluated in a prime-boost schedule with ALVAC in the ongoing HVTN (HIV Vaccine Trials Network) 702 efficacy trial, we selected the bivalent clade C Env immunogens gp120 C.1086 and gp120 TV1 in combination with the MF59 adjuvant. However, we hypothesized that the adjuvant system AS01, that is included in the pediatric RTS,S malaria vaccine, would promote Env-specific antibody responses superior to those of the oil-in-water MF59 emulsion adjuvant. In a second study arm, we compared two emulsions, glucopyranosyl lipid adjuvant formulated in a stable emulsion (GLA-SE) and 3M-052-SE, containing Toll-like receptor 4 (TLR4) and TLR7/TLR8 (TLR7/8) ligand, respectively. The latter adjuvant had been previously demonstrated to be especially effective in activating neonatal antigen-presenting cells. Our results demonstrate that different adjuvants drive quantitatively or qualitatively distinct responses to the bivalent Env vaccine. AS01 induced higher Env-specific plasma IgG antibody levels than the antigen in MF59 and promoted improved antibody function in infants, and 3M-052-SE outperformed GLA-SE by inducing the highest breadth and functionality of antibody responses. Thus, distinct adjuvants are likely to be required for maximizing vaccine-elicited immune responses in infants, particularly when immunization in infancy aims to elicit both perinatal and lifelong immunity against challenging pathogens such as HIV.IMPORTANCE Alum remains the adjuvant of choice for pediatric vaccines. Yet the distinct nature of the developing immune system in infants likely requires novel adjuvants targeted specifically at the pediatric population to reach maximal vaccine efficacy with an acceptable safety profile. The current study supports the idea that additional adjuvants for pediatric vaccines should be, and need to be, tested in infants for their potential to enhance immune responses. Using an infant macaque model, our results suggest that both AS01 and 3M-052-SE can significantly improve and better sustain HIV Env-specific antibody responses than alum. Despite the limited number of animals, the results revealed interesting differences that warrant further testing of promising novel adjuvant candidates in larger preclinical and clinical studies to define the mechanisms leading to adjuvant-improved antibody responses and to identify targets for adjuvant and vaccine optimization.
Collapse
|
20
|
Ignacio BJ, Albin TJ, Esser-Kahn AP, Verdoes M. Toll-like Receptor Agonist Conjugation: A Chemical Perspective. Bioconjug Chem 2018; 29:587-603. [PMID: 29378134 PMCID: PMC10642707 DOI: 10.1021/acs.bioconjchem.7b00808] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Toll-like receptors (TLRs) are vital elements of the mammalian immune system that function by recognizing pathogen-associated molecular patterns (PAMPs), bridging innate and adaptive immunity. They have become a prominent therapeutic target for the treatment of infectious diseases, cancer, and allergies, with many TLR agonists currently in clinical trials or approved as immunostimulants. Numerous studies have shown that conjugation of TLR agonists to other molecules can beneficially influence their potency, toxicity, pharmacokinetics, or function. The functional properties of TLR agonist conjugates, however, are highly dependent on the ligation strategy employed. Here, we review the chemical structural requirements for effective functional TLR agonist conjugation. In addition, we provide similar analysis for those that have yet to be conjugated. Moreover, we discuss applications of covalent TLR agonist conjugation and their implications for clinical use.
Collapse
Affiliation(s)
- Bob J. Ignacio
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Tyler J. Albin
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
| | - Aaron P. Esser-Kahn
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
- Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Martijn Verdoes
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| |
Collapse
|