1
|
Li J, Kang Y, Wu ZX, Yang SF, Tian YY, Zhu XQ, Zheng XN. Live-attenuated PruΔgra72 strain of Toxoplasma gondii induces strong protective immunity against acute and chronic toxoplasmosis in mice. Parasit Vectors 2024; 17:377. [PMID: 39237959 PMCID: PMC11378421 DOI: 10.1186/s13071-024-06461-9] [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: 07/03/2024] [Accepted: 08/20/2024] [Indexed: 09/07/2024] Open
Abstract
BACKGROUND Toxoplasma gondii is an intracellular opportunistic pathogenic protozoan that poses serious threats, particularly in immunocompromised individuals. In the absence of a robust prophylactic measure, the mitigation and management of toxoplasmosis present formidable challenges to public health. We recently found that GRA72 plays an important role in parasitophorous vacuole (PV) morphology, growth and virulence of T. gondii. However, whether gra72-deficient strain can be used as a vaccine remains unknown. METHODS We first examined the attenuated virulence of gra72 gene knockout strain (PruΔgra72) and the parasite load in organs of the infected mice. Subsequently, we evaluated the immune-protective effects of the PruΔgra72 vaccination against challenge with various types of T. gondii tachyzoites and Pru cysts. Furthermore, levels of antibodies and cytokines induced by PruΔgra72 vaccination were examined. Statistical analysis was conducted by Student's t-test or Mantel-Cox log-rank test based on data obtained from three independent experiments with GraphPad Prism 8.0. RESULTS We found that PruΔgra72 strain exhibited a significantly attenuated virulence even at the highest dose of 5 × 107 tachyzoites in Kunming mice model. The significant decrease of brain cyst burden and parasite load in the organs of the PruΔgra72-infected mice suggested its potentiality as a live-attenuated vaccine. Hence, we explored the protective immunity of PruΔgra72 vaccination against toxoplasmosis. Results showed that vaccination with 5 × 106 PruΔgra72 tachyzoites triggered a strong and sustained Th1-biased immune response, marked by significantly increased levels of anti-T. gondii IgG antibodies, and significantly higher levels of Th1 type cytokines (IL-2, IL-12 and IFN-γ) compared to that of Th2 type (IL-4 and IL-10). Vaccination with 5 × 106 PruΔgra72 tachyzoites in mice conferred long-term protection against T. gondii infection by less virulent tachyzoites (ToxoDB#9 PYS and Pru strains) and Pru cysts, provided partial protection against acute infection by high virulent Type I RH tachyzoites and significantly decreased brain cyst burden of chronically infected mice. CONCLUSIONS The avirulent PruΔgra72 induced strong protective immunity against acute and chronic T. gondii infection and is a promising candidate for developing a safe and effective live-attenuated vaccine against T. gondii infection.
Collapse
Affiliation(s)
- Jing Li
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Jinzhong, Shanxi Province, 030801, People's Republic of China
| | - Yu Kang
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Jinzhong, Shanxi Province, 030801, People's Republic of China
| | - Ze-Xuan Wu
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Jinzhong, Shanxi Province, 030801, People's Republic of China
| | - Shu-Feng Yang
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Jinzhong, Shanxi Province, 030801, People's Republic of China
| | - Yu-Yang Tian
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Jinzhong, Shanxi Province, 030801, People's Republic of China
| | - Xing-Quan Zhu
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Jinzhong, Shanxi Province, 030801, People's Republic of China.
| | - Xiao-Nan Zheng
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Jinzhong, Shanxi Province, 030801, People's Republic of China.
| |
Collapse
|
2
|
Ju K, Zhang Y, Xu Z, Li L, Zhao X, Zhou H. Protective Efficacy of a Novel DNA Vaccine with a CL264 Molecular Adjuvant against Toxoplasma gondii in a Murine Model. Vaccines (Basel) 2024; 12:577. [PMID: 38932306 PMCID: PMC11209281 DOI: 10.3390/vaccines12060577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 05/15/2024] [Accepted: 05/22/2024] [Indexed: 06/28/2024] Open
Abstract
Toxoplasmosis is a significant global zoonosis with devastating impacts, and an effective vaccine against toxoplasmosis for humans has not yet been developed. In this study, we designed and formulated a novel DNA vaccine encoding the inhibitor of STAT1 transcriptional activity (IST) of T. gondii utilizing the eukaryotic expression vector pEGFP-N1 for the first time, with CL264 being a molecular adjuvant. Following intramuscular injection of the vaccine into mice, the levels of antibodies and cytokines were assessed to evaluate the immune response. Additionally, mice were challenged with highly virulent RH-strain tachyzoites of T. gondii, and their survival time was observed. The results show that the levels of IgG in serum, the ratio of IgG2a/IgG1 and the levels of IFN-γ in splenocytes of mice were significantly higher in the pEGFP-TgIST group and the pEGFP-TgIST + CL264 group than in the control group. In addition, the proportion of CD4+/CD8+ T cells was higher in mice immunized with either the pEGFP-TgIST group (p < 0.001) or the pEGFP-TgIST + CL264 group (p < 0.05) compared to the three control groups. Notably, TgIST-immunized mice exhibited prolonged survival times after T. gondii RH strain infection (p < 0.05). Our findings collectively demonstrate that the TgIST DNA vaccine elicits a significant humoral and cellular immune response and offers partial protection against acute T. gondii infection in the immunized mice, which suggests that TgIST holds potential as a candidate for further development as a DNA vaccine.
Collapse
Affiliation(s)
| | | | | | | | | | - Huaiyu Zhou
- Department of Pathogen Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, China; (K.J.); (Y.Z.); (Z.X.); (L.L.); (X.Z.)
| |
Collapse
|
3
|
Xing Y, Yang J, Yao P, Xie L, Liu M, Cai Y. Comparison of the immune response and protection against the experimental Toxoplasma gondii infection elicited by immunization with the recombinant proteins BAG1, ROP8, and BAG1-ROP8. Parasite Immunol 2024; 46:e13023. [PMID: 38372452 DOI: 10.1111/pim.13023] [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: 08/03/2023] [Revised: 01/08/2024] [Accepted: 01/08/2024] [Indexed: 02/20/2024]
Abstract
Toxoplasmosis is one of the most dangerous zoonotic diseases, causing serious economic losses worldwide due to abortion and reproductive problems. Vaccination is the best way to prevent disease; thus, it is imperative to develop a candidate vaccine for toxoplasmosis. BAG1 and ROP8 have the potential to become vaccine candidates. In this study, rTgBAG1, rTgROP8, and rTgBAG1-rTgROP8 were used to evaluate the immune effect of vaccines in each group by detecting the humoral and cellular immune response levels of BABL/c mice after immunization and the ability to resist acute and chronic infection with Toxoplasma gondii (T. gondii). We divided the mice into vaccine groups with different proteins, and the mice were immunized on days 0, 14, and 28. The protective effects of different proteins against T. gondii were analysed by measuring the cytokines, serum antibodies, splenocyte proliferation assay results, survival time, and number and diameter of brain cysts of mice after infection. The vaccine groups exhibited substantially higher IgG, IgG1, and IgG2a levels and effectively stimulated lymphocyte proliferation. The levels of IFN-γ and IL-2 in the vaccine group were significantly increased. The survival time of the mice in each vaccine group was prolonged and the diameter of the cysts in the vaccine group was smaller; rTgBAG1-rTgROP8 had a better protection. Our study showed that the rTgBAG1, rTgROP8, and rTgBAG1-rTgROP8 recombinant protein vaccines are partial but effective approaches against acute or chronic T. gondii infection. They are potential candidates for a toxoplasmosis vaccine.
Collapse
Affiliation(s)
- Yien Xing
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, China
- Department of Microbiology and Parasitology, the Provincial Laboratory of Pathogen Biology of Anhui, and the Key Laboratory of Zoonoses of Anhui, Anhui Medical University, Hefei, China
| | - Jun Yang
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, China
- Department of Microbiology and Parasitology, the Provincial Laboratory of Pathogen Biology of Anhui, and the Key Laboratory of Zoonoses of Anhui, Anhui Medical University, Hefei, China
| | - Pengjing Yao
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, China
- Department of Microbiology and Parasitology, the Provincial Laboratory of Pathogen Biology of Anhui, and the Key Laboratory of Zoonoses of Anhui, Anhui Medical University, Hefei, China
| | - Linding Xie
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, China
- Department of Microbiology and Parasitology, the Provincial Laboratory of Pathogen Biology of Anhui, and the Key Laboratory of Zoonoses of Anhui, Anhui Medical University, Hefei, China
| | - Min Liu
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, China
- Department of Microbiology and Parasitology, the Provincial Laboratory of Pathogen Biology of Anhui, and the Key Laboratory of Zoonoses of Anhui, Anhui Medical University, Hefei, China
| | - Yihong Cai
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, China
- Department of Microbiology and Parasitology, the Provincial Laboratory of Pathogen Biology of Anhui, and the Key Laboratory of Zoonoses of Anhui, Anhui Medical University, Hefei, China
| |
Collapse
|
4
|
Zhang Y, Li S, Chu H, Li J, Lu S, Zheng B. A novel mRNA vaccine, TGGT1_278620 mRNA-LNP, prolongs the survival time in BALB/c mice with acute toxoplasmosis. Microbiol Spectr 2024; 12:e0286623. [PMID: 38038457 PMCID: PMC10783036 DOI: 10.1128/spectrum.02866-23] [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: 07/18/2023] [Accepted: 11/01/2023] [Indexed: 12/02/2023] Open
Abstract
IMPORTANCE Toxoplasma gondii, an obligate intracellular eukaryotic parasite, can infect about one-third of the world's population. One vaccine, Toxovax, has been developed and licensed commercially; however, it is only used in the sheep industry to reduce the losses caused by congenital toxoplasmosis. Various other vaccine approaches have been explored, including excretory secretion antigen vaccines, subunit vaccines, epitope vaccines, and DNA vaccines. However, current research has not yet developed a safe and effective vaccine for T. gondii. Here, we generated an mRNA vaccine candidate against T. gondii. We investigated the efficacy of vaccination with a novel identified candidate, TGGT1_278620, in a mouse infection model. We screened T. gondii-derived protective antigens at the genome-wide level, combined them with mRNA-lipid nanoparticle vaccine technology against T. gondii, and investigated immune-related factors and mechanisms. Our findings might contribute to developing vaccines for immunizing humans and animals against T. gondii.
Collapse
Affiliation(s)
- Yizhuo Zhang
- Laboratory of Pathogen Biology, School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- Engineering Research Center of Novel Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
| | - Shiyu Li
- Laboratory of Pathogen Biology, School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- Engineering Research Center of Novel Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
| | - Hongkun Chu
- Laboratory of Pathogen Biology, School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- Engineering Research Center of Novel Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
| | - Jing Li
- Laboratory of Pathogen Biology, School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- Engineering Research Center of Novel Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
| | - Shaohong Lu
- Laboratory of Pathogen Biology, School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- Engineering Research Center of Novel Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
- Key Laboratory of Bio-Tech Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
| | - Bin Zheng
- Laboratory of Pathogen Biology, School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- School of Basic Medicine and Forensics, Hangzhou Medical College, Hangzhou, China
- Engineering Research Center of Novel Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
- Key Laboratory of Bio-Tech Vaccine of Zhejiang Province, Hangzhou Medical College, Hangzhou, China
| |
Collapse
|
5
|
Shi Y, Li J, Yang W, Chen J. Protective immunity induced by DNA vaccine containing Tg GRA35, Tg GRA42, and Tg GRA43 against Toxoplasma gondii infection in Kunming mice. Front Cell Infect Microbiol 2023; 13:1236130. [PMID: 38029261 PMCID: PMC10644269 DOI: 10.3389/fcimb.2023.1236130] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 08/15/2023] [Indexed: 12/01/2023] Open
Abstract
Background Toxoplasma gondii can cause congenital infection and abortion in humans and warm-blooded animals. T. gondii dense granule proteins, GRA35, GRA42, and GRA43, play a critical role in the establishment of chronic infection. However, their potential to induce protective immunity against T. gondii infection remains unexplored. Objective This study aimed to test the efficacy of a DNA vaccine encompassing GRA35, GRA42, and GRA43 in inducing protective immunity against the highly virulent T. gondii RH strain (type I) and the brain cyst-forming PRU strain (type II). Methods The eukaryotic plasmids pVAX-GRA35, pVAX-GRA42, and pVAX-GRA43 were constructed and formulated into two- or three-gene cocktail DNA vaccines. The indirect immunofluorescence assay (IFA) was used to analyze their expression and immunogenicity. Mice were immunized with a single-gene, two-genes, or multicomponent eukaryotic plasmid, intramuscularly. We assessed antibody levels, cytotoxic T-cell (CTL) responses, cytokines, and lymphocyte surface markers by using flow cytometry. Additionally, mouse survival and cyst numbers in the brain of mice challenged 1 to 2 months postvaccination were determined. Results Specific humoral and cellular immune responses were elicited in mice immunized with single-, two-, or three-gene cocktail DNA vaccine, as indicated by significant increases in serum antibody concentrations of total IgG, IgG2a/IgG1 ratio, cytokine levels (IFN-γ, IL-2, IL-12, IL-4, and IL-10), lymphocyte proliferation, lymphocyte populations (CD4+ and CD8+ T lymphocytes), CTL activities, and survival, as well as decreased brain cysts, in comparison with control mice. Moreover, compared with pVAX-GRA35 + pVAX-GRA42, pVAX-GRA42 + pVAX-GRA43, or pVAX-GRA35 + pVAX-GRA43, multicomponent DNA vaccine with three genes (pVAX-GRA35 + pVAX-GRA42 + pVAX-GRA43) induced the higher humoral and cellular immune responses, including serum antibody concentrations, cytokine levels, lymphocyte proliferation, lymphocyte populations, CTL activities and survival, resulting in prolonged survival time and reduced brain cyst loads. Furthermore, mice immunized with pVAX-GRA35 + pVAX-GRA42, pVAX-GRA42 + pVAX-GRA43, or pVAX-GRA35 + pVAX-GRA43 showed greater Th1 immune responses and protective efficacy than the single-gene-vaccinated groups. Conclusion These results demonstrate that TgGRA35, TgGRA42, or TgGRA43 are vaccine candidates against T. gondii infection, and the three-gene DNA vaccine cocktail conferred the strongest protection against T. gondii infection.
Collapse
Affiliation(s)
- Youbo Shi
- The Affiliated People’s Hospital of Ningbo University, Ningbo, China
| | - Jianbing Li
- The Affiliated People’s Hospital of Ningbo University, Ningbo, China
| | - Weili Yang
- The Affiliated People’s Hospital of Ningbo University, Ningbo, China
| | - Jia Chen
- The Affiliated People’s Hospital of Ningbo University, Ningbo, China
- Health Science Center, Ningbo University, Ningbo, Zhejiang, China
| |
Collapse
|
6
|
Guo HT, Tan J, He YL, Li X, Liang X, Li ZY. Immunization of BALB/c Mice with Killed Tachyzoites of Toxoplasma gondii against Acute Toxoplasmosis. IRANIAN JOURNAL OF PARASITOLOGY 2023; 18:435-444. [PMID: 38169648 PMCID: PMC10758075 DOI: 10.18502/ijpa.v18i4.14243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 08/18/2023] [Indexed: 01/05/2024]
Abstract
Background Toxoplasma gondii with widespread distribution infects over one third of human populations in the world and can cause serious life-threatening diseases especially for the immunodeficient patients in acute toxoplasmosis. As the clinical pharmaceutical drugs with severe side effects for treatment and non-ideal extant vaccines for prevention, more work starves to be done for keeping advantages in the athletics. Methods Aluminum adjuvant and hybrid formaldehyde-killed tachyzoites of T. gondii RH and GT1 isolates were prepared to intramuscularly immunize BALB/c mice for five times at 0, 3, 7, 14 and 21 days post first injection. The triggered humoral and cellular immune responses at two weeks post the last immunization and the survival times of infected mice were examined for the hybrid immunization scheme judgement. Results The anti-RH and anti-GT1 specific antibodies were both increased at one week prior to challenge (P < 0.05), and the survival times of immunized mice (7.33 ± 0.71 d for RH, 7.22 ± 0.97 d for GT1) against acute toxoplasmosis were significantly prolonged by the immunizations performed in the study compared to blank control (6.67 ± 0.50 d for RH, 6.33 ± 0.71 d for GT1; P < 0.05), with the higher IFN-γ, IL-2 and IL-12p70 in sera, the elevated CD3e+CD4+ T and CD3e+CD8a+ T cells, and the enhanced lymphocyte proliferation in spleen (P < 0.05). Conclusion The hybrid killed tachyzoites with aluminum adjuvant induced humoral and cellular immune responses of mice, and offered mildly protective efficacy against acute toxoplasmosis.
Collapse
Affiliation(s)
- Hai-Ting Guo
- Guangxi Key Laboratory of Brain and Cognitive Neuroscience, College of Basic Medicine, Guilin Medical University, Guilin, P.R. China
| | - Jie Tan
- Guangxi Key Laboratory of Brain and Cognitive Neuroscience, College of Basic Medicine, Guilin Medical University, Guilin, P.R. China
| | - Yu-Lin He
- Guangxi Key Laboratory of Brain and Cognitive Neuroscience, College of Basic Medicine, Guilin Medical University, Guilin, P.R. China
| | - Xia Li
- Guangxi Key Laboratory of Brain and Cognitive Neuroscience, College of Basic Medicine, Guilin Medical University, Guilin, P.R. China
| | - Xue Liang
- Guangxi Key Laboratory of Brain and Cognitive Neuroscience, College of Basic Medicine, Guilin Medical University, Guilin, P.R. China
| | - Zhong-Yuan Li
- Guangxi Key Laboratory of Brain and Cognitive Neuroscience, College of Basic Medicine, Guilin Medical University, Guilin, P.R. China
| |
Collapse
|
7
|
Chu KB, Quan FS. Recent progress in vaccine development targeting pre-clinical human toxoplasmosis. PARASITES, HOSTS AND DISEASES 2023; 61:231-239. [PMID: 37648228 PMCID: PMC10471472 DOI: 10.3347/phd.22097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 05/30/2023] [Indexed: 09/01/2023]
Abstract
Toxoplasma gondii is an intracellular parasitic organism affecting all warm-blooded vertebrates. Due to the unavailability of commercialized human T. gondii vaccine, many studies have been reported investigating the protective efficacy of pre-clinical T. gondii vaccines expressing diverse antigens. Careful antigen selection and implementing multifarious immunization strategies could enhance protection against toxoplasmosis in animal models. Although none of the available vaccines could remove the tissue-dwelling parasites from the host organism, findings from these pre-clinical toxoplasmosis vaccine studies highlighted their developmental potential and provided insights into rational vaccine design. We herein explored the progress of T. gondii vaccine development using DNA, protein subunit, and virus-like particle vaccine platforms. Specifically, we summarized the findings from the pre-clinical toxoplasmosis vaccine studies involving T. gondii challenge infection in mice published in the past 5 years.
Collapse
Affiliation(s)
- Ki-Back Chu
- Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, Core Research Institute, School of Medicine, Kyung Hee University, Seoul 02447,
Korea
| | - Fu-Shi Quan
- Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, Core Research Institute, School of Medicine, Kyung Hee University, Seoul 02447,
Korea
- Department of Medical Zoology, School of Medicine, Kyung Hee University, Seoul 02447,
Korea
| |
Collapse
|
8
|
Sang X, Li X, Chen R, Feng Y, He T, Zhang X, El-Ashram S, Al-Olayan E, Yang N. Co-Immunization with DNA Vaccines Expressing SABP1 and SAG1 Proteins Effectively Enhanced Mice Resistance to Toxoplasma gondii Acute Infection. Vaccines (Basel) 2023; 11:1190. [PMID: 37515006 PMCID: PMC10384583 DOI: 10.3390/vaccines11071190] [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: 06/04/2023] [Revised: 06/28/2023] [Accepted: 06/29/2023] [Indexed: 07/30/2023] Open
Abstract
Toxoplasma gondii (T. gondii) has many intermediate hosts, obligately invades nucleated cells, and seriously threatens human and animal health due to a lack of effective drugs and vaccines. Sialic acid-binding protein 1 (SABP1) is a novel invasion-related protein that, like surface antigen 1 (SAG1), is found on the plasma membrane of T. gondii. To investigate the immunogenicity and protective efficacy of DNA vaccines expressing SABP1 and SAG1 proteins against T. gondii acute infection, the recombinant plasmids pVAX1-SABP1 and pVAX1-SAG1 were produced and administered intramuscularly in Balb/c mice. Serum antibody levels and subtypes, lymphocyte proliferation, and cytokines were used to assess immunized mice's humoral and cellular immune responses. Furthermore, the ability of DNA vaccines to protect mice against T. gondii RH tachyzoites was tested. Immunized mice exhibited substantially higher IgG levels, with IgG2a titers higher than IgG1. When the immune group mice's splenocytes were stimulated with T. gondii lysate antigen, Th1-type cytokines (IL-12p70, IFN-γ, and IL-2) and Th2-type cytokine (IL-4) increased significantly. The combined DNA vaccine significantly increased the immunized mouse survival compared to the control group, with an average death time extended by 4.33 ± 0.6 days (p < 0.0001). These findings show that DNA vaccines based on the SABP1 and SAG1 genes induced robust humoral and cellular immunity in mice, effectively protecting against acute toxoplasmosis and potentially serving as a viable option for vaccination to prevent T. gondii infection.
Collapse
Affiliation(s)
- Xiaoyu Sang
- Key Laboratory of Livestock Infectious Diseases, Shenyang Agricultural University, Ministry of Education, Shenyang 110866, China
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110866, China
| | - Xiang Li
- Key Laboratory of Livestock Infectious Diseases, Shenyang Agricultural University, Ministry of Education, Shenyang 110866, China
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110866, China
| | - Ran Chen
- Key Laboratory of Livestock Infectious Diseases, Shenyang Agricultural University, Ministry of Education, Shenyang 110866, China
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110866, China
| | - Ying Feng
- Key Laboratory of Livestock Infectious Diseases, Shenyang Agricultural University, Ministry of Education, Shenyang 110866, China
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110866, China
| | - Ting He
- Key Laboratory of Livestock Infectious Diseases, Shenyang Agricultural University, Ministry of Education, Shenyang 110866, China
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110866, China
| | - Xiaohan Zhang
- Key Laboratory of Livestock Infectious Diseases, Shenyang Agricultural University, Ministry of Education, Shenyang 110866, China
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110866, China
| | - Saeed El-Ashram
- Department of Zoology, Faculty of Science, Kafrelsheikh University, Kafr El-Sheikh 33516, Egypt
| | - Ebtsam Al-Olayan
- Department of Zoology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Na Yang
- Key Laboratory of Livestock Infectious Diseases, Shenyang Agricultural University, Ministry of Education, Shenyang 110866, China
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110866, China
| |
Collapse
|
9
|
Zhao P, Li J, Li X, Dong J, Wang X, Zhang N, Li S, Sun M, Zhang X, Wang Z, Liang M, Li Y, Cao L, Gong P. The NLRP3 inflammasome recognizes alpha-2 and alpha-7.3 giardins and decreases the pathogenicity of Giardia duodenalis in mice. Parasit Vectors 2023; 16:85. [PMID: 36869360 PMCID: PMC9983531 DOI: 10.1186/s13071-023-05688-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 02/01/2023] [Indexed: 03/05/2023] Open
Abstract
BACKGROUND Giardia duodenalis is a parasitic organism that can cause giardiasis, an intestinal infection, particularly prevalent in young children, with clinical symptoms of diarrhea. We previously reported that extracellular G. duodenalis triggers intracellular nucleotide-binding oligomerization-like receptor 3 (NLRP3) inflammasome activation and regulates the host inflammatory response by secreting extracellular vesicles (EVs). However, the exact pathogen-associated molecular patterns in G. duodenalis EVs (GEVs) involved in this process and the role of the NLRP3 inflammasome in giardiasis remain to be elucidated. METHODS Recombinant eukaryotic expression plasmids of pcDNA3.1(+)-alpha-2 and alpha-7.3 giardins in GEVs were constructed, transfected into primary mouse peritoneal macrophages and screened by measuring the expression levels of the inflammasome target molecule caspase-1 p20. The preliminary identification of G. duodenalis alpha-2 and alpha-7.3 giardins was further verified by measuring the protein expression levels of key molecules of the NLRP3 inflammasome (NLRP3, pro-interleukin-1 beta [IL-1β], pro-caspase-1, and caspase-1 p20), the secretion levels of IL-1β, the level of apoptosis speck-like protein (ASC) oligomerization and the immunofluorescence localization of NLRP3 and ASC. The roles of the NLRP3 inflammasome in G. duodenalis pathogenicity were then evaluated using mice in which NLRP3 activation was blocked (NLRP3-blocked mice), and body weight, parasite burden in the duodenum and histopathological changes in the duodenum were monitored. In addition, we explored whether alpha-2 and alpha-7.3 giardins triggered IL-1β secretion in vivo through the NLRP3 inflammasome and determined the roles of these molecules in G. duodenalis pathogenicity in mice. RESULTS Alpha-2 and alpha-7.3 giardins triggered NLRP3 inflammasome activation in vitro. This led to caspase-1 p20 activation, upregulation of the protein expression levels of NLRP3, pro-IL-1β and pro-caspase-1, significant enhancement of IL-1β secretion, ASC speck formation in the cytoplasm and also induction of ASC oligomerization. Deletion of the NLRP3 inflammasome aggravated G. duodenalis pathogenicity in mice. Compared to wild-type mice gavaged with cysts, mice gavaged with cysts in NLRP3-blocked mice displayed increased trophozoite loads and severe duodenal villus damage, characterized by necrotic crypts with atrophy and branching. In vivo assays revealed that alpha-2 and alpha-7.3 giardins could induce IL-1β secretion through the NLRP3 inflammasome and that immunization with alpha-2 and alpha-7.3 giardins decreased G. duodenalis pathogenicity in mice. CONCLUSIONS Overall, the results of the present study revealed that alpha-2 and alpha-7.3 giardins trigger host NLRP3 inflammasome activation and decrease G. duodenalis infection ability in mice, which are promising targets for the prevention of giardiasis.
Collapse
Affiliation(s)
- Panpan Zhao
- State Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, 130062, Jilin Province, People's Republic of China
| | - Jianhua Li
- State Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, 130062, Jilin Province, People's Republic of China
| | - Xin Li
- State Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, 130062, Jilin Province, People's Republic of China
| | - Jingquan Dong
- State Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, 130062, Jilin Province, People's Republic of China.,Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, Jiangsu Ocean University, Lianyungang, 222005, Jiangsu Province, People's Republic of China
| | - Xiaocen Wang
- State Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, 130062, Jilin Province, People's Republic of China
| | - Nan Zhang
- State Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, 130062, Jilin Province, People's Republic of China
| | - Shan Li
- State Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, 130062, Jilin Province, People's Republic of China
| | - Min Sun
- State Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, 130062, Jilin Province, People's Republic of China
| | - Xichen Zhang
- State Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, 130062, Jilin Province, People's Republic of China
| | - Zhibang Wang
- College of Life Science, Jilin University, Changchun, 130062, Jilin Province, People's Republic of China
| | - Min Liang
- State Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, 130062, Jilin Province, People's Republic of China
| | - Ying Li
- State Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, 130062, Jilin Province, People's Republic of China
| | - Lili Cao
- State Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, 130062, Jilin Province, People's Republic of China. .,Jilin Academy of Animal Husbandry and Veterinary Medicine, Changchun, 130062, Jilin Province, People's Republic of China.
| | - Pengtao Gong
- State Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, 130062, Jilin Province, People's Republic of China.
| |
Collapse
|