scholarly journals Immunogenicity of Recombinant-Deficient Lactobacillus casei with Complementary Plasmid Expressing Alanine Racemase Gene and Core Neutralizing Epitope Antigen against Porcine Epidemic Diarrhea Virus

Vaccines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1084
Author(s):  
Fengsai Li ◽  
Xiaona Wang ◽  
Xiaolong Fan ◽  
Ling Sui ◽  
Hailin Zhang ◽  
...  
Keyword(s):  
Immune Responses ◽  
Porcine Epidemic Diarrhea Virus ◽  
Lactobacillus Casei ◽  
Oral Vaccine ◽  
Mucosal Vaccine ◽  
Alanine Racemase ◽  
Main Function ◽  
Neutralizing Epitope ◽  
Diarrhea Virus ◽  
Porcine Epidemic Diarrhea

Porcine epidemic diarrhea (PED), which is caused by the porcine epidemic diarrhea virus (PEDV), has occurred worldwide and poses a serious threat to the pig industry. Intestine is the main function site of PEDV; therefore, it is important to develop an oral mucosal immunity vaccine against this virus infection. Most traditional plasmid delivery vectors use antibiotic genes as a selective marker, easily leading to antibiotic accumulation and gene contamination. In this study, to explore whether the alanine racemase gene (Alr) could be used as a screening marker and develop an efficient oral vaccine against PEDV infection, a recombinant strain was constructed using Lactobacillus casei with Alr deletion (L. casei ΔAlr W56) to deliver the Alr gene and a core-neutralizing epitope (COE) antigen. This recombinant bacterium efficiently induced secretory immunoglobulin A (SIgA)-based mucosal and immunoglobulin G (IgG)-based humoral immune responses via oral vaccination in mice. Compared to the other strains, the recombinant bacteria were able to grow without the addition of D-alanine, revealing that Alr in the plasmid could function normally in defective bacteria. This oral mucosal vaccine would provide a useful strategy to substitute the application of antibiotics in the future and induce efficient immune responses against PEDV infection.

scholarly journals Immune Responses in Pregnant Sows Induced by Recombinant Lactobacillus johnsonii Expressing the COE Protein of Porcine Epidemic Diarrhea Virus Provide Protection for Piglets against PEDV Infection

Viruses ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 7
Author(s):  
Dianzhong Zheng ◽  
Xiaona Wang ◽  
Ning Ju ◽  
Zhaorui Wang ◽  
Ling Sui ◽  
...  
Keyword(s):  
Dendritic Cell ◽  
Immune Responses ◽  
Porcine Epidemic Diarrhea Virus ◽  
Oral Vaccine ◽  
Economic Losses ◽  
Antigen Delivery ◽  
Lactobacillus Johnsonii ◽  
Diarrhea Virus ◽  
Porcine Epidemic Diarrhea

Porcine epidemic diarrhea (PED) induced by porcine epidemic diarrhea virus (PEDV) is an intestinal infectious disease in pigs that causes serious economic losses to the pig industry. To develop an effective oral vaccine against PEDV infection, we used a swine-origin Lactobacillus johnsonii (L. johnsonii) as an antigen delivery carrier. A recombinant strain pPG-T7g10-COE/L. johnsonii (L. johnsonii-COE) expressing COE protein (a neutralizing epitope of the viral spike protein) was generated. The immunomodulatory effect on dendritic cell in vitro and immunogenicity in pregnant sows was evaluated following oral administration. L. johnsonii-COE could activate monocyte-derived dendritic cell (MoDC) maturation and triggered cell immune responses. After oral vaccination with L. johnsonii-COE, levels of anti-PEDV-specific serum IgG, IgA, and IgM antibodies as well as mucosal secretory immunoglobulin A (SIgA) antibody were induced in pregnant sows. High levels of PEDV-specific SIgA and IgG antibodies were detected in the maternal milk, which provide effective protection for the piglets against PEDV infection. In summary, oral L. johnsonii-COE was able to efficiently activate anti-PEDV humoral and cellular immune responses, demonstrating potential as a vaccine for use in sows to provide protection of their piglets against PEDV.

Construction of recombinant lactobacilli expressing the core neutralizing epitope (COE) of porcine epidemic diarrhea virus and a fusion protein consisting of COE and Escherichia coli heat-labile enterotoxin B, and comparison of the immune responses by orogastric immunization

2012 ◽  
Vol 58 (11) ◽  
pp. 1258-1267 ◽  
Author(s):  
Jun-Wei Ge ◽  
Di-Qiu Liu ◽  
Yi-Jing Li
Keyword(s):  
Escherichia Coli ◽  
Porcine Epidemic Diarrhea Virus ◽  
Mucosal Vaccine ◽  
Interleukin 4 ◽  
Neutralizing Epitope ◽  
Diarrhea Virus ◽  
The Core ◽  
Heat Labile ◽  
Porcine Epidemic Diarrhea ◽  
Enterotoxin B

The core neutralizing epitope (COE) region of porcine epidemic diarrhea virus (PEDV) plays an important role in the development of the subunit vaccine against PEDV infection. To enhance the vaccine’s immunogenicity, Escherichia coli heat-labile enterotoxin B (LTB) has usually been adopted as a molecular adjuvant. In this study, the COE and LTB–COE genes were engineered into the Lactobacillus –Escherichia coli shuttle vectors pSAPG1 (surface-displaying) and pSAPG2 (secreting) followed by electrotransformation into Lactobacillus casei (Lc) to yield the following recombinant strains: Lc:PG1-LTB-COE, Lc:PG2-LTB-COE, Lc:PG1-COE, and Lc:PG2-COE. Our results showed that mice immunized orogastrically with L. casei expressing COE or LTB–COE produced secretory immunoglobulin A and immunoglobulin G with the ability to neutralize PEDV in sera and mucus. Moreover, higher levels of interleukin-4 and gamma interferon were also exhibited compared with negative control. These data displayed the tendency of Lc:PG2-LTB-COE > Lc:PG1-LTB-COE > Lc:PG2-COE > Lc:PG1-COE at the same time point. Taken together, LTB–COE is more suitable for Lactobacillus expressing system to engineer mucosal vaccine against PEDV infection.

scholarly journals Host Factors Affecting Generation of Immunity Against Porcine Epidemic Diarrhea Virus in Pregnant and Lactating Swine and Passive Protection of Neonates

Pathogens ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 130 ◽  
Author(s):  
Stephanie N. Langel ◽  
Qiuhong Wang ◽  
Anastasia N. Vlasova ◽  
Linda J. Saif
Keyword(s):  
Immune Responses ◽  
Porcine Epidemic Diarrhea Virus ◽  
Host Factors ◽  
Diarrhea Virus ◽  
Maternal Immunization ◽  
Immunization Strategies ◽  
Suckling Piglets ◽  
Porcine Epidemic Diarrhea ◽  
Lactogenic Immunity ◽  
Highly Virulent

Porcine epidemic diarrhea virus (PEDV) is a highly virulent re-emerging enteric coronavirus that causes acute diarrhea, dehydration, and up to 100% mortality in neonatal suckling piglets. Despite this, a safe and effective PEDV vaccine against highly virulent strains is unavailable, making PEDV prevention and control challenging. Lactogenic immunity induced via the gut-mammary gland-secretory IgA (sIgA) axis, remains the most promising and effective way to protect suckling piglets from PEDV. Therefore, a successful PEDV vaccine must induce protective maternal IgA antibodies that passively transfer into colostrum and milk. Identifying variables that influence lymphocyte migration and IgA secretion during gestation and lactation is imperative for designing maternal immunization strategies that generate the highest amount of lactogenic immune protection against PEDV in suckling piglets. Because pregnancy-associated immune alterations influence viral pathogenesis and adaptive immune responses in many different species, a better understanding of host immune responses to PEDV in pregnant swine may translate into improved maternal immunization strategies against enteric pathogens for multiple species. In this review, we discuss the role of host factors during pregnancy on antiviral immunity and their implications for generating protective lactogenic immunity in suckling neonates.

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