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Lloren KKS, Sivasankar C, Lee JH. Comparative immunogenic and immunoprotective activities of PCV2d Cap and Rep antigens delivered by an efficient eukaryotic expression system engineered into a Salmonella vaccine vector. Vet Microbiol 2024; 295:110151. [PMID: 38870752 DOI: 10.1016/j.vetmic.2024.110151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 06/05/2024] [Accepted: 06/09/2024] [Indexed: 06/15/2024]
Abstract
Porcine circovirus type 2 (PCV2) stands as a predominant etiological agent in porcine circovirus-associated diseases. To manage the spread of the disease, it is necessary to develop a next-generation vaccine expressing PCV2 antigens that target the prevailing genotype such as PCV2d. A bacterial-mediated vaccine delivery by live-attenuated Salmonella has attracted interest for its low-cost production and highly effective vaccine delivery. Thus, in this study, we utilized the advantages of the Salmonella-mediated vaccine delivery by cloning PCV2d cap and rep into a eukaryotic expression plasmid pJHL204 and electroporation into an engineered live-attenuated Salmonella Typhimurium JOL2500 (Δlon, ΔcpxR, ΔsifA, Δasd). The eukaryotic antigen expression by JOL2995 (p204:cap) and JOL2996 (p204:rep) was confirmed in vitro and in vivo which showed efficient antigen delivery. Furthermore, vaccination of mice model with the vaccine candidates elicited humoral and cell-mediated immune responses as depicted by high levels of PCV2-specific antibodies, CD4+ and CD8+ T cells, and neutralizing antibodies, especially by JOL2995 (p204:cap) which correlated with the significant decrease in the viral load in PCV2d-challenged mice. Interestingly, JOL2996 (p204:rep) may not have elicited high levels of neutralizing antibodies and protective efficacy, but it elicited considerably higher cell-mediated immune responses. This study demonstrated Salmonella-mediated vaccine delivery system coupled with the eukaryotic expression vector can efficiently deliver and express the target PCV2d antigens for strong induction of immune response and protective efficacy in mice model, further supporting the potential application of the Salmonella-mediated vaccine delivery system as an effective novel approach in vaccine strategies for PCV2d.
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Affiliation(s)
- Khristine Kaith S Lloren
- College of Veterinary Medicine, Jeonbuk National University, Iksan, Jeollabuk-do 54596, Republic of Korea
| | - Chandran Sivasankar
- College of Veterinary Medicine, Jeonbuk National University, Iksan, Jeollabuk-do 54596, Republic of Korea
| | - John Hwa Lee
- College of Veterinary Medicine, Jeonbuk National University, Iksan, Jeollabuk-do 54596, Republic of Korea.
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Park JY, Senevirathne A, Lloren KKS, Lee JH. The Effect of Tryptophan-to-Tyrosine Mutation at Position 61 of the Nonstructural Protein of Severe Fever with Thrombocytopenia Syndrome Virus on Viral Replication through Autophagosome Modulation. Int J Mol Sci 2024; 25:6394. [PMID: 38928101 PMCID: PMC11203599 DOI: 10.3390/ijms25126394] [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: 03/27/2024] [Revised: 05/29/2024] [Accepted: 06/06/2024] [Indexed: 06/28/2024] Open
Abstract
In our prior investigations, we elucidated the role of the tryptophan-to-tyrosine substitution at the 61st position in the nonstructural protein NSsW61Y in diminishing the interaction between nonstructural proteins (NSs) and nucleoprotein (NP), impeding viral replication. In this study, we focused on the involvement of NSs in replication via the modulation of autophagosomes. Initially, we examined the impact of NP expression levels, a marker for replication, upon the infection of HeLa cells with severe fever thrombocytopenia syndrome virus (SFTSV), with or without the inhibition of NP binding. Western blot analysis revealed a reduction in NP levels in NSsW61Y-expressing conditions. Furthermore, the expression levels of the canonical autophagosome markers p62 and LC3 decreased in HeLa cells expressing NSsW61Y, revealing the involvement of individual viral proteins on autophagy. Subsequent experiments confirmed that NSsW61Y perturbs autophagy flux, as evidenced by reduced levels of LC3B and p62 upon treatment with chloroquine, an inhibitor of autophagosome-lysosome fusion. LysoTracker staining demonstrated a decrease in lysosomes in cells expressing the NS mutant compared to those expressing wild-type NS. We further explored the mTOR-associated regulatory pathway, a key regulator affected by NS mutant expression. The observed inhibition of replication could be linked to conformational changes in the NSs, impairing their binding to NP and altering mTOR regulation, a crucial upstream signaling component in autophagy. These findings illuminate the intricate interplay between NSsW61Y and the suppression of host autophagy machinery, which is crucial for the generation of autophagosomes to facilitate viral replication.
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Affiliation(s)
| | | | | | - John Hwa Lee
- College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Republic of Korea
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Alatrash R, Herrera BB. The Adaptive Immune Response against Bunyavirales. Viruses 2024; 16:483. [PMID: 38543848 PMCID: PMC10974645 DOI: 10.3390/v16030483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/18/2024] [Accepted: 03/19/2024] [Indexed: 05/23/2024] Open
Abstract
The Bunyavirales order includes at least fourteen families with diverse but related viruses, which are transmitted to vertebrate hosts by arthropod or rodent vectors. These viruses are responsible for an increasing number of outbreaks worldwide and represent a threat to public health. Infection in humans can be asymptomatic, or it may present with a range of conditions from a mild, febrile illness to severe hemorrhagic syndromes and/or neurological complications. There is a need to develop safe and effective vaccines, a process requiring better understanding of the adaptive immune responses involved during infection. This review highlights the most recent findings regarding T cell and antibody responses to the five Bunyavirales families with known human pathogens (Peribunyaviridae, Phenuiviridae, Hantaviridae, Nairoviridae, and Arenaviridae). Future studies that define and characterize mechanistic correlates of protection against Bunyavirales infections or disease will help inform the development of effective vaccines.
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Affiliation(s)
- Reem Alatrash
- Rutgers Global Health Institute, Rutgers University, New Brunswick, NJ 08901, USA
- Department of Medicine, Division of Allergy, Immunology, and Infectious Diseases and Child Health Institute of New Jersey, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ 08901, USA
| | - Bobby Brooke Herrera
- Rutgers Global Health Institute, Rutgers University, New Brunswick, NJ 08901, USA
- Department of Medicine, Division of Allergy, Immunology, and Infectious Diseases and Child Health Institute of New Jersey, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ 08901, USA
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Oh B, Park SC, Yang MS, Yang D, Ham G, Tark D, You MJ, Oh SI, Kim B. Difference in Intraspecies Transmissibility of Severe Fever with Thrombocytopenia Syndrome Virus Depending on Abrogating Type 1 Interferon Signaling in Mice. Viruses 2024; 16:401. [PMID: 38543766 PMCID: PMC10974630 DOI: 10.3390/v16030401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 02/20/2024] [Accepted: 03/01/2024] [Indexed: 05/23/2024] Open
Abstract
Severe fever with thrombocytopenia syndrome (SFTS), a tick-borne zoonotic disease, is caused by infection with SFTS virus (SFTSV). A previous study reported that human-to-human direct transmission of SFTSV can occur. However, potential animal-to-animal transmission of SFTSV without ticks has not been fully clarified. Thus, the objective of this study was to investigate potential mice-to-mice transmission of SFTSV by co-housing three groups of mice [i.e., wild-type mice (WT), mice injected with an anti-type I interferon-α receptor-blocking antibody (IFNAR Ab), and mice with knockout of type I interferon-α receptor (IFNAR KO)] as spreaders or recipients with different immune competence. As a result, co-housed IFNAR Ab and IFNAR KO mice showed body weight loss with SFTS viral antigens detected in their sera, extracorporeal secretions, and various organs. Based on histopathology, white pulp atrophy in the spleen was observed in all co-housed mice except WT mice. These results obviously show that IFNAR Ab and IFNAR KO mice, as spreaders, exhibited higher transmissibility to co-housed mice than WT mice. Moreover, IFNAR KO mice, as recipients, were more susceptible to SFTSV infection than WT mice. These findings suggest that type I interferon signaling is a pivotal factor in mice intraspecies transmissibility of SFTSV in the absence of vectors such as ticks.
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Affiliation(s)
- Byungkwan Oh
- Biosafety Research Institute, College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Republic of Korea; (B.O.); (S.-C.P.); (M.-S.Y.); (D.Y.); (G.H.); (M.J.Y.); (S.-I.O.)
| | - Seok-Chan Park
- Biosafety Research Institute, College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Republic of Korea; (B.O.); (S.-C.P.); (M.-S.Y.); (D.Y.); (G.H.); (M.J.Y.); (S.-I.O.)
| | - Myeon-Sik Yang
- Biosafety Research Institute, College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Republic of Korea; (B.O.); (S.-C.P.); (M.-S.Y.); (D.Y.); (G.H.); (M.J.Y.); (S.-I.O.)
| | - Daram Yang
- Biosafety Research Institute, College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Republic of Korea; (B.O.); (S.-C.P.); (M.-S.Y.); (D.Y.); (G.H.); (M.J.Y.); (S.-I.O.)
| | - Gaeul Ham
- Biosafety Research Institute, College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Republic of Korea; (B.O.); (S.-C.P.); (M.-S.Y.); (D.Y.); (G.H.); (M.J.Y.); (S.-I.O.)
| | - Dongseob Tark
- Laboratory for Infectious Disease Prevention, Korea Zoonosis Research Institute, Jeonbuk National University, 820-120, Hana-ro, Iksan 54531, Republic of Korea;
| | - Myung Jo You
- Biosafety Research Institute, College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Republic of Korea; (B.O.); (S.-C.P.); (M.-S.Y.); (D.Y.); (G.H.); (M.J.Y.); (S.-I.O.)
| | - Sang-Ik Oh
- Biosafety Research Institute, College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Republic of Korea; (B.O.); (S.-C.P.); (M.-S.Y.); (D.Y.); (G.H.); (M.J.Y.); (S.-I.O.)
| | - Bumseok Kim
- Biosafety Research Institute, College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Republic of Korea; (B.O.); (S.-C.P.); (M.-S.Y.); (D.Y.); (G.H.); (M.J.Y.); (S.-I.O.)
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Lloren KKS, Lee JH. Live-Attenuated Salmonella-Based Oral Vaccine Candidates Expressing PCV2d Cap and Rep by Novel Expression Plasmids as a Vaccination Strategy for Mucosal and Systemic Immune Responses against PCV2d. Vaccines (Basel) 2023; 11:1777. [PMID: 38140182 PMCID: PMC10748173 DOI: 10.3390/vaccines11121777] [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: 10/28/2023] [Revised: 11/25/2023] [Accepted: 11/27/2023] [Indexed: 12/24/2023] Open
Abstract
Oral vaccines are highly envisaged for veterinary applications due to their convenience and ability to induce protective mucosal immunity as the first line of defense. The present investigation harnessed live-attenuated Salmonella Typhimurium to orally deliver novel expression vector systems containing the Cap and Rep genes from porcine circovirus type 2 (PCV2), a significant swine pathogen. The antigen expression by the vaccine candidates JOL2885 and JOL2886, comprising eukaryotic pJHL204 and pro-eukaryotic expression pJHL270 plasmids, respectively, was confirmed by Western blot and IFA. We evaluated their immunogenicity and protective efficacy through oral vaccination in a mouse model. This approach elicited both mucosal and systemic immunity against PCV2d. Oral administration of the candidates induced PCV2-specific sIgA, serum IgG antibodies, and neutralizing antibodies, resulting in reduced viral loads in the livers and lungs of PCV2d-challenged mice. T-lymphocyte proliferation and flow-cytometry assays confirmed enhanced cellular immune responses after oral inoculation. The synchronized elicitation of both Th1 and Th2 responses was also confirmed by enhanced expression of TNF-α, IFN-γ, IL-4, MHC-I, and MHC-II. Our findings highlight the effectiveness and safety of the constructs with an engineered-attenuated S. Typhimurium, suggesting its potential application as an oral PCV2 vaccine candidate.
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Affiliation(s)
| | - John Hwa Lee
- College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Republic of Korea;
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