Escherichia coli Nissle 1917 Enhances Efficacy of Oral Attenuated Human Rotavirus Vaccine in a Gnotobiotic Piglet Model

Abstract

Human rotavirus (HRV) infection is a major cause of viral gastroenteritis in young children worldwide. Current oral vaccines perform poorly in developing countries where efficacious vaccines are needed the most. Therefore, an alternative affordable strategy to enhance efficacy of the current RV vaccines is necessary. This study evaluated the effects of colonization of neonatal gnotobiotic (Gn) pigs with Escherichia coli Nissle (EcN) 1917 and Lacticaseibacillus rhamnosus GG (LGG) probiotics on immunogenicity and protective efficacy of oral attenuated (Att) HRV vaccine. EcN-colonized pigs had reduced virulent HRV (VirHRV) shedding and decreased diarrhea severity compared with the LGG-colonized group. They also had enhanced HRV-specific IgA antibody titers in serum and antibody secreting cell numbers in tissues pre/post VirHRV challenge, HRV-specific IgA antibody titers in intestinal contents, and B-cell subpopulations in tissues post VirHRV challenge. EcN colonization also enhanced T-cell immune response, promoted dendritic cells and NK cell function, reduced production of proinflammatory cytokines/Toll like receptor (TLR), and increased production of immunoregulatory cytokines/TLR expression in various tissues pre/post VirHRV challenge. Thus, EcN probiotic adjuvant with AttHRV vaccine enhances the immunogenicity and protective efficacy of AttHRV to a greater extent than LGG and it can be used as a safe and economical oral vaccine adjuvant.

Probiotics and probiotic-based vaccines: A novel approach for improving vaccine efficacy

“…For example, Escherichia coli Nissle (EcN) 1917 was used to colonize antibiotic-treated and human infant fecal microbiota transplanted Gn piglets and immune response was evaluated to human Rotavirus (HRV). As a result, the humoral and cellular immune responses were enhanced, and EcN biofilm increased the frequencies of systemic memory and IgA + B cells (109,110). Likewise, the Lactococcus lactis strain decreased severity and symptoms in volunteers with Dengue fever (DF) compared to the placebo group, promoted IFN-γ and TGF-β cytokines secretion, and reduced serum IgE and IL-4 cytokine levels in mice models (111,112).…”

Vitamin A deficiency and vitamin A supplementation affect innate and T cell immune responses to rotavirus A infection in a conventional sow model

“…The cells were incubated at 37°C, 5% CO 2 overnight ( 41 ). Antibody staining for NK cells markers (SWC3a - CD16 + ), markers for different subsets of DCs (pDCs- SWC3a + CD4 + CD11b - , conventional DCs (cDCs) - SWC3a + CD4 - CD11b +, CD103 + DCs - SWC3a + CD4 - CD103 + ) was performed as previously described ( 35 , 43 , 46 , 47 ) (Antibodies and isotype controls are in Table S1 ). Antibody staining for Treg cells (natural Tregs-CD4 + /CD8 + CD25 + FOXP3 + , inducible Tregs - CD4 + /CD8 + CD25 − FOXP3 + and activated Tregs- CD4 + /CD8 + CD25 + FOXP3 − ) were performed as described previously by Chattha et al.…”

“…Antibody staining for Treg cells (natural Tregs-CD4 + /CD8 + CD25 + FOXP3 + , inducible Tregs - CD4 + /CD8 + CD25 − FOXP3 + and activated Tregs- CD4 + /CD8 + CD25 + FOXP3 − ) were performed as described previously by Chattha et al. ( 47 , 48 ). To determine the frequencies of RVA-specific IFN-γ-producing CD4 + and CD8 + cells (CD3 + , CD4 + /CD8 + IFN-γ), MNCs were restimulated in vitro with the semi purified RVA virus (12 μg/ml) and porcine cross-reactive human CD49d monoclonal antibody (0.5 μg/ml) (clone 9F10; BD Pharmingen) for 18 h and stained as previously described ( 48 , 49 ).…”

“…Antibody staining for NK cells markers (SWC3a -CD16 + ), markers for different subsets of DCs (pDCs-SWC3a + CD4 + CD11b -, conventional DCs (cDCs) -SWC3a + CD4 -CD11b +, CD103 + DCs -SWC3a + CD4 -CD103 + ) was performed as previously described (35, 43, 46, 47) (Antibodies and isotype controls are in Table S1). Antibody staining for Treg cells (natural Tregs-CD4 + /CD8 + CD25 + FOXP3 + , inducible Tregs -CD4 + /CD8 + CD25 − FOXP3 + and activated Tregs-CD4 + / CD8 + CD25 + FOXP3 − ) were performed as described previously by Chattha et al (47,48). To determine the frequencies of RVAspecific IFN-g-producing CD4 + and CD8 + cells (CD3 + , CD4 + /CD8 + IFN-g), MNCs were restimulated in vitro with the semi purified RVA virus (12 mg/ml) and porcine cross-reactive human CD49d monoclonal antibody (0.5 mg/ml) (clone 9F10; BD Pharmingen) for 18 h and stained as previously described (48,49).…”

Intestinal Engineered Probiotics as Living Therapeutics: Chassis Selection, Colonization Enhancement, Gene Circuit Design, and Biocontainment

“…Traditional probiotics can protect the intestinal mucosa, − modulate gut microbiota, and produce beneficial metabolites . Moreover, they can regulate the secretion of immune factors and exert anti-inflammatory effects. ,− Traditional probiotics also exhibit activity against various pathogenic microorganisms and tumors, ,,,− and are widely used in foods, health products, and medicine.…”