Continuously improving the developmental process and the efficacy of oral vaccines is essential i... more Continuously improving the developmental process and the efficacy of oral vaccines is essential in the fight against intestinal pathogens. A promising strategy for vaccination applying safe, biodegradable and non-replicating antigen delivery systems has gained increased interest for eliciting cellular and humoral immune responses. The current study evaluates the potential of β-glucan particles (GP) as an oral antigen delivery system and their adjuvant characteristics. GP are efficiently internalized by human intestinal epithelial cell lines (Caco-2 and HT-29 cells), without exerting negative effects on cell viability. GP triggered the expression of pro-inflammatory cytokines IL-23p19, IL-8 and the β-glucan receptors dectin-1 and TLR2 by activated Caco-2 cells, and CCL20 in HT-29 cells. In contrast, the expression level of TGF-β, an important mediator of oral tolerance, was significantly downregulated in HT-29 cells. Additionally, adoptive transfer experiments showed proliferating ov...
The inflammatory cytokine TNF-α is a central mediator in many immune-mediated diseases,
such as C... more The inflammatory cytokine TNF-α is a central mediator in many immune-mediated diseases, such as Crohn’s disease (CD), spondyloarthritis (SpA) and chronic obstructive pulmonary disease (COPD). Epidemiologic studies have shown that cigarette smoking (CS) is a prominent common risk factor in these TNF-dependent diseases. We exposed TNFΔARE mice; in which a systemic TNF-α overexpression leads to the development of inflammation; to 2 or 4 weeks of air or CS. We investigated the effect of deregulated TNF expression on CS-induced pulmonary inflammation and the effect of CS exposure on the initiation and progression of gut and joint inflammation. Upon 2 weeks of CS exposure, inflammation in lungs of TNFΔARE mice was significantly aggravated. However, upon 4 weeks of CS-exposure, this aggravation was no longer observed. TNFΔARE mice have no increases in CD4+ and CD8+ T cells and a diminished neutrophil response in the lungs after 4 weeks of CS exposure. In the gut and joints of TNFΔARE mice, 2 or 4 weeks of CS exposure did not modulate the development of inflammation. In conclusion, CS exposure does not modulate gut and joint inflammation in TNFΔARE mice. The lung responses towards CS in TNFΔARE mice however depend on the duration of CS exposure.
Epidemiological evidence demonstrates that smoking is the most important environmental risk
fact... more Epidemiological evidence demonstrates that smoking is the most important environmental risk
factor in Crohn's disease while it positively interferes with the disease course of ulcerative colitis.
However, the underlying mechanisms through which smoking exerts this divergent effect and
affects pathogenesis of inflammatory bowel disease are largely unknown. Animal smoke models
are good models to investigate the impact of cigarette smoke on intestinal physiology and
inflammation. They enable one to explore the interaction of smoke components and the
gut on cellular and molecular level, clarifying how smoking interferes with normal gut function
and with disease course in inflammatory conditions. This review describes the currently
used animal models for studying the impact of cigarette smoke on the intestinal tract. We
first discuss the different methods for simulation of smoking. Furthermore, we focus on
the effect of smoke exposure on normal gut physiology and immunology, on experimental
(entero)colitis, and on inflammation-induced neoplasia. Based on this current knowledge,
a hypothesis is formulated about the mechanisms through which cigarette smoke interferes
with the gut in normal and pathological conditions.
Environmental Microbiology, IF = 6,24, Jun 1, 2015
Allais L, Kerckhof FM, Verschuere S, Bracke KR, De Smet R, Laukens D, Van den Abbeele P, De Vos M... more Allais L, Kerckhof FM, Verschuere S, Bracke KR, De Smet R, Laukens D, Van den Abbeele P, De Vos M, Boon N, Brusselle GG, Cuvelier CA, Van de Wiele T.
Inflammatory Bowel Diseases (IBD) are complex multifactorial diseases characterized by an inappropriate host response to an altered commensal microbiome and dysfunctional mucus barrier. Cigarette smoking is the best known environmental risk factor in IBD. Here, we studied the influence of chronic smoke exposure on the gut microbiome and mucus layer composition in conventional mice. We compared smoke-exposed to air-exposed mice (n = 12) after a smoke exposure of 24 weeks. Both Illumina sequencing (n = 6) and denaturing gradient gel electrophoresis (DGGE) (n = 12) showed that bacterial activity and community structure were significantly altered in the colon due to smoke exposure. Interestingly, an increase of Lachnospiraceae sp. activity in the colon was observed. Also, changes in the mRNA expression Muc2 and Muc3 increased in the ileum, whereas Muc4 increased in the distal colon of smoke-exposed mice (n = 6). Furthermore, we observed increased Cxcl2 and decreased Ifn-γ in the ileum, and increased Il-6 and decreased Tgf-β in the proximal colon. Tight junction gene expression remained unchanged. We infer that the modulating role of chronic smoke exposure as a latently present risk factor in the gut may be driven by the altered epithelial mucus profiles and changes in microbiome composition and immune factors.
De Smet R, Verschuere S, Allais L, Leclercq G, Dierendonck M, De Geest BG, Van Driessche I, Demoo... more De Smet R, Verschuere S, Allais L, Leclercq G, Dierendonck M, De Geest BG, Van Driessche I, Demoor T, Cuvelier CA.
During the past decade, extensive research has undeniably improved the formulation and delivery of oral vaccines. Nevertheless, several factors, such as the harsh gastrointestinal environment together with tolerance induction to exogenous antigens, have thus far impeded the optimal effectiveness and clinical application of oral delivery systems. The current study encompasses an initial evaluation of the stability, biocompatibility, and cellular uptake of two promising candidate systems for oral antigen delivery, that is, calcium carbonate- (CP) and mannitol-templated (MP) porous microspheres. Both spray-dried formulations were efficiently internalized by human intestinal epithelial cells (Caco-2 and HT-29) and degraded into phagolysosomal intracellular compartments. In addition, cellular particle uptake and processing significantly up-regulated the expression of (HLA) class-II and costimulatory molecules on intestinal epithelial cells. Even though the high surface-area-to-volume ratio of the microspheres was expected to favor protease access, antigen release was remarkably limited in simulated intestinal fluid and was even absent under gastric conditions. Finally, neither CP nor MP exerted cytotoxicity upon prolonged in vitro incubation with high antigen concentration. Altogether, these data support the potential of CP and MP for oral antigen delivery and motivate the further development of these promising carrier systems in in vivo studies.
De Smet R, Allais L, Cuvelier CA.
Oral vaccination is the most challenging vaccination method ... more De Smet R, Allais L, Cuvelier CA.
Oral vaccination is the most challenging vaccination method due to the administration route. However, oral vaccination has socio-economic benefits and provides the possibility of stimulating both humoral and cellular immune responses at systemic and mucosal sites. Despite the advantages of oral vaccination, only a limited number of oral vaccines are currently approved for human use. During the last decade, extensive research regarding antigen-based oral vaccination methods have improved immunogenicity and induced desired immunological outcomes. Nevertheless, several factors such as the harsh gastro-intestinal environment and oral tolerance impede the clinical application of oral delivery systems. To date, human clinical trials investigating the efficacy of these systems are still lacking. This review addresses the rationale and key biological and physicochemical aspects of oral vaccine design and highlights the use of yeast-derived β-glucan microparticles as an oral vaccine delivery platform.
Rebecca De Smet, Tine Demoor, Stephanie Verschuere, Melissa Dullaers, Gary R Ostroff, Georges Lec... more Rebecca De Smet, Tine Demoor, Stephanie Verschuere, Melissa Dullaers, Gary R Ostroff, Georges Leclercq, Liesbeth Allais, Charles Pilette, Marijke Dierendonck, Bruno G De Geest, Claude A Cuvelier.
Continuously improving the developmental process and the efficacy of oral vaccines is essential in the fight against intestinal pathogens. A promising strategy for vaccination applying safe, biodegradable and non-replicating antigen delivery systems has gained increased interest for eliciting cellular and humoral immune responses. The current study evaluates the potential of β-glucan particles (GP) as an oral antigen delivery system and their adjuvant characteristics. GP are efficiently internalized by human intestinal epithelial cell lines (Caco-2 and HT-29 cells), without exerting negative effects on cell viability. GP triggered the expression of pro-inflammatory cytokines IL-23p19, IL-8 and the β-glucan receptors dectin-1 and TLR2 by activated Caco-2 cells, and CCL20 in HT-29 cells. In contrast, the expression level of TGF-β, an important mediator of oral tolerance, was significantly downregulated in HT-29 cells. Additionally, adoptive transfer experiments showed proliferating ovalbumin (OVA)-specific CD4+ T cells mainly in the spleens of GP-OVA-fed mice. Furthermore, we detected a significantly increased IL-17 and a trend towards increased IFN-γ production in the spleen of GP-OVA-fed mice upon antigen restimulation. Oral administration of GP-OVA induced increased OVA-specific IgA, secretory-IgA (S-IgA) and secretory component (SC) production in intestinal fluids. Our data show that GP vehicles are able to deliver OVA via an oral route allowing efficient antigen presentation alongside adaptive immune activation, resulting in a Th17-biased response and the production of OVA-specific IgA, secretory-IgA and secretory component antibodies.
Continuously improving the developmental process and the efficacy of oral vaccines is essential i... more Continuously improving the developmental process and the efficacy of oral vaccines is essential in the fight against
intestinal pathogens. A promising strategy for vaccination applying safe, biodegradable and non-replicating antigen
delivery systems has gained increased interest for eliciting cellular and humoral immune responses. The current
study evaluates the potential of β-glucan particles (GP) as an oral antigen delivery systemand their adjuvant characteristics.
GP are efficiently internalized by human intestinal epithelial cell lines (Caco-2 and HT-29 cells), without
exerting negative effects on cell viability. GP triggered the expression of pro-inflammatory cytokines IL-23p19, IL-8
and the β-glucan receptors dectin-1 and TLR2 by activated Caco-2 cells, and CCL20 in HT-29 cells. In contrast, the
expression level of TGF-β, an important mediator of oral tolerance, was significantly downregulated in HT-29 cells.
Additionally, adoptive transfer experiments showed proliferating ovalbumin (OVA)-specific CD4+T cells mainly in
the spleens of GP-OVA-fed mice. Furthermore, we detected a significantly increased IL-17 and a trend towards
increased IFN-γ production in the spleen of GP-OVA-fed mice upon antigen restimulation. Oral administration of
GP-OVA induced increased OVA-specific IgA, secretory-IgA (S-IgA) and secretory component (SC) production in intestinal
fluids. Our data show that GP vehicles are able to deliver OVA via an oral route allowing efficient antigen
presentation alongside adaptive immune activation, resulting in a Th17-biased response and the production of
OVA-specific IgA, secretory-IgA and secretory component antibodies.
Continuously improving the developmental process and the efficacy of oral vaccines is essential i... more Continuously improving the developmental process and the efficacy of oral vaccines is essential in the fight against intestinal pathogens. A promising strategy for vaccination applying safe, biodegradable and non-replicating antigen delivery systems has gained increased interest for eliciting cellular and humoral immune responses. The current study evaluates the potential of β-glucan particles (GP) as an oral antigen delivery system and their adjuvant characteristics. GP are efficiently internalized by human intestinal epithelial cell lines (Caco-2 and HT-29 cells), without exerting negative effects on cell viability. GP triggered the expression of pro-inflammatory cytokines IL-23p19, IL-8 and the β-glucan receptors dectin-1 and TLR2 by activated Caco-2 cells, and CCL20 in HT-29 cells. In contrast, the expression level of TGF-β, an important mediator of oral tolerance, was significantly downregulated in HT-29 cells. Additionally, adoptive transfer experiments showed proliferating ov...
The inflammatory cytokine TNF-α is a central mediator in many immune-mediated diseases,
such as C... more The inflammatory cytokine TNF-α is a central mediator in many immune-mediated diseases, such as Crohn’s disease (CD), spondyloarthritis (SpA) and chronic obstructive pulmonary disease (COPD). Epidemiologic studies have shown that cigarette smoking (CS) is a prominent common risk factor in these TNF-dependent diseases. We exposed TNFΔARE mice; in which a systemic TNF-α overexpression leads to the development of inflammation; to 2 or 4 weeks of air or CS. We investigated the effect of deregulated TNF expression on CS-induced pulmonary inflammation and the effect of CS exposure on the initiation and progression of gut and joint inflammation. Upon 2 weeks of CS exposure, inflammation in lungs of TNFΔARE mice was significantly aggravated. However, upon 4 weeks of CS-exposure, this aggravation was no longer observed. TNFΔARE mice have no increases in CD4+ and CD8+ T cells and a diminished neutrophil response in the lungs after 4 weeks of CS exposure. In the gut and joints of TNFΔARE mice, 2 or 4 weeks of CS exposure did not modulate the development of inflammation. In conclusion, CS exposure does not modulate gut and joint inflammation in TNFΔARE mice. The lung responses towards CS in TNFΔARE mice however depend on the duration of CS exposure.
Epidemiological evidence demonstrates that smoking is the most important environmental risk
fact... more Epidemiological evidence demonstrates that smoking is the most important environmental risk
factor in Crohn's disease while it positively interferes with the disease course of ulcerative colitis.
However, the underlying mechanisms through which smoking exerts this divergent effect and
affects pathogenesis of inflammatory bowel disease are largely unknown. Animal smoke models
are good models to investigate the impact of cigarette smoke on intestinal physiology and
inflammation. They enable one to explore the interaction of smoke components and the
gut on cellular and molecular level, clarifying how smoking interferes with normal gut function
and with disease course in inflammatory conditions. This review describes the currently
used animal models for studying the impact of cigarette smoke on the intestinal tract. We
first discuss the different methods for simulation of smoking. Furthermore, we focus on
the effect of smoke exposure on normal gut physiology and immunology, on experimental
(entero)colitis, and on inflammation-induced neoplasia. Based on this current knowledge,
a hypothesis is formulated about the mechanisms through which cigarette smoke interferes
with the gut in normal and pathological conditions.
Environmental Microbiology, IF = 6,24, Jun 1, 2015
Allais L, Kerckhof FM, Verschuere S, Bracke KR, De Smet R, Laukens D, Van den Abbeele P, De Vos M... more Allais L, Kerckhof FM, Verschuere S, Bracke KR, De Smet R, Laukens D, Van den Abbeele P, De Vos M, Boon N, Brusselle GG, Cuvelier CA, Van de Wiele T.
Inflammatory Bowel Diseases (IBD) are complex multifactorial diseases characterized by an inappropriate host response to an altered commensal microbiome and dysfunctional mucus barrier. Cigarette smoking is the best known environmental risk factor in IBD. Here, we studied the influence of chronic smoke exposure on the gut microbiome and mucus layer composition in conventional mice. We compared smoke-exposed to air-exposed mice (n = 12) after a smoke exposure of 24 weeks. Both Illumina sequencing (n = 6) and denaturing gradient gel electrophoresis (DGGE) (n = 12) showed that bacterial activity and community structure were significantly altered in the colon due to smoke exposure. Interestingly, an increase of Lachnospiraceae sp. activity in the colon was observed. Also, changes in the mRNA expression Muc2 and Muc3 increased in the ileum, whereas Muc4 increased in the distal colon of smoke-exposed mice (n = 6). Furthermore, we observed increased Cxcl2 and decreased Ifn-γ in the ileum, and increased Il-6 and decreased Tgf-β in the proximal colon. Tight junction gene expression remained unchanged. We infer that the modulating role of chronic smoke exposure as a latently present risk factor in the gut may be driven by the altered epithelial mucus profiles and changes in microbiome composition and immune factors.
De Smet R, Verschuere S, Allais L, Leclercq G, Dierendonck M, De Geest BG, Van Driessche I, Demoo... more De Smet R, Verschuere S, Allais L, Leclercq G, Dierendonck M, De Geest BG, Van Driessche I, Demoor T, Cuvelier CA.
During the past decade, extensive research has undeniably improved the formulation and delivery of oral vaccines. Nevertheless, several factors, such as the harsh gastrointestinal environment together with tolerance induction to exogenous antigens, have thus far impeded the optimal effectiveness and clinical application of oral delivery systems. The current study encompasses an initial evaluation of the stability, biocompatibility, and cellular uptake of two promising candidate systems for oral antigen delivery, that is, calcium carbonate- (CP) and mannitol-templated (MP) porous microspheres. Both spray-dried formulations were efficiently internalized by human intestinal epithelial cells (Caco-2 and HT-29) and degraded into phagolysosomal intracellular compartments. In addition, cellular particle uptake and processing significantly up-regulated the expression of (HLA) class-II and costimulatory molecules on intestinal epithelial cells. Even though the high surface-area-to-volume ratio of the microspheres was expected to favor protease access, antigen release was remarkably limited in simulated intestinal fluid and was even absent under gastric conditions. Finally, neither CP nor MP exerted cytotoxicity upon prolonged in vitro incubation with high antigen concentration. Altogether, these data support the potential of CP and MP for oral antigen delivery and motivate the further development of these promising carrier systems in in vivo studies.
De Smet R, Allais L, Cuvelier CA.
Oral vaccination is the most challenging vaccination method ... more De Smet R, Allais L, Cuvelier CA.
Oral vaccination is the most challenging vaccination method due to the administration route. However, oral vaccination has socio-economic benefits and provides the possibility of stimulating both humoral and cellular immune responses at systemic and mucosal sites. Despite the advantages of oral vaccination, only a limited number of oral vaccines are currently approved for human use. During the last decade, extensive research regarding antigen-based oral vaccination methods have improved immunogenicity and induced desired immunological outcomes. Nevertheless, several factors such as the harsh gastro-intestinal environment and oral tolerance impede the clinical application of oral delivery systems. To date, human clinical trials investigating the efficacy of these systems are still lacking. This review addresses the rationale and key biological and physicochemical aspects of oral vaccine design and highlights the use of yeast-derived β-glucan microparticles as an oral vaccine delivery platform.
Rebecca De Smet, Tine Demoor, Stephanie Verschuere, Melissa Dullaers, Gary R Ostroff, Georges Lec... more Rebecca De Smet, Tine Demoor, Stephanie Verschuere, Melissa Dullaers, Gary R Ostroff, Georges Leclercq, Liesbeth Allais, Charles Pilette, Marijke Dierendonck, Bruno G De Geest, Claude A Cuvelier.
Continuously improving the developmental process and the efficacy of oral vaccines is essential in the fight against intestinal pathogens. A promising strategy for vaccination applying safe, biodegradable and non-replicating antigen delivery systems has gained increased interest for eliciting cellular and humoral immune responses. The current study evaluates the potential of β-glucan particles (GP) as an oral antigen delivery system and their adjuvant characteristics. GP are efficiently internalized by human intestinal epithelial cell lines (Caco-2 and HT-29 cells), without exerting negative effects on cell viability. GP triggered the expression of pro-inflammatory cytokines IL-23p19, IL-8 and the β-glucan receptors dectin-1 and TLR2 by activated Caco-2 cells, and CCL20 in HT-29 cells. In contrast, the expression level of TGF-β, an important mediator of oral tolerance, was significantly downregulated in HT-29 cells. Additionally, adoptive transfer experiments showed proliferating ovalbumin (OVA)-specific CD4+ T cells mainly in the spleens of GP-OVA-fed mice. Furthermore, we detected a significantly increased IL-17 and a trend towards increased IFN-γ production in the spleen of GP-OVA-fed mice upon antigen restimulation. Oral administration of GP-OVA induced increased OVA-specific IgA, secretory-IgA (S-IgA) and secretory component (SC) production in intestinal fluids. Our data show that GP vehicles are able to deliver OVA via an oral route allowing efficient antigen presentation alongside adaptive immune activation, resulting in a Th17-biased response and the production of OVA-specific IgA, secretory-IgA and secretory component antibodies.
Continuously improving the developmental process and the efficacy of oral vaccines is essential i... more Continuously improving the developmental process and the efficacy of oral vaccines is essential in the fight against
intestinal pathogens. A promising strategy for vaccination applying safe, biodegradable and non-replicating antigen
delivery systems has gained increased interest for eliciting cellular and humoral immune responses. The current
study evaluates the potential of β-glucan particles (GP) as an oral antigen delivery systemand their adjuvant characteristics.
GP are efficiently internalized by human intestinal epithelial cell lines (Caco-2 and HT-29 cells), without
exerting negative effects on cell viability. GP triggered the expression of pro-inflammatory cytokines IL-23p19, IL-8
and the β-glucan receptors dectin-1 and TLR2 by activated Caco-2 cells, and CCL20 in HT-29 cells. In contrast, the
expression level of TGF-β, an important mediator of oral tolerance, was significantly downregulated in HT-29 cells.
Additionally, adoptive transfer experiments showed proliferating ovalbumin (OVA)-specific CD4+T cells mainly in
the spleens of GP-OVA-fed mice. Furthermore, we detected a significantly increased IL-17 and a trend towards
increased IFN-γ production in the spleen of GP-OVA-fed mice upon antigen restimulation. Oral administration of
GP-OVA induced increased OVA-specific IgA, secretory-IgA (S-IgA) and secretory component (SC) production in intestinal
fluids. Our data show that GP vehicles are able to deliver OVA via an oral route allowing efficient antigen
presentation alongside adaptive immune activation, resulting in a Th17-biased response and the production of
OVA-specific IgA, secretory-IgA and secretory component antibodies.
Uploads
Papers by Rebecca De Smet
such as Crohn’s disease (CD), spondyloarthritis (SpA) and chronic obstructive pulmonary
disease (COPD). Epidemiologic studies have shown that cigarette smoking (CS) is
a prominent common risk factor in these TNF-dependent diseases. We exposed TNFΔARE
mice; in which a systemic TNF-α overexpression leads to the development of inflammation;
to 2 or 4 weeks of air or CS. We investigated the effect of deregulated TNF expression on
CS-induced pulmonary inflammation and the effect of CS exposure on the initiation and progression
of gut and joint inflammation. Upon 2 weeks of CS exposure, inflammation in lungs
of TNFΔARE mice was significantly aggravated. However, upon 4 weeks of CS-exposure,
this aggravation was no longer observed. TNFΔARE mice have no increases in CD4+ and
CD8+ T cells and a diminished neutrophil response in the lungs after 4 weeks of CS exposure.
In the gut and joints of TNFΔARE mice, 2 or 4 weeks of CS exposure did not modulate
the development of inflammation. In conclusion, CS exposure does not modulate gut and
joint inflammation in TNFΔARE mice. The lung responses towards CS in TNFΔARE mice however
depend on the duration of CS exposure.
factor in Crohn's disease while it positively interferes with the disease course of ulcerative colitis.
However, the underlying mechanisms through which smoking exerts this divergent effect and
affects pathogenesis of inflammatory bowel disease are largely unknown. Animal smoke models
are good models to investigate the impact of cigarette smoke on intestinal physiology and
inflammation. They enable one to explore the interaction of smoke components and the
gut on cellular and molecular level, clarifying how smoking interferes with normal gut function
and with disease course in inflammatory conditions. This review describes the currently
used animal models for studying the impact of cigarette smoke on the intestinal tract. We
first discuss the different methods for simulation of smoking. Furthermore, we focus on
the effect of smoke exposure on normal gut physiology and immunology, on experimental
(entero)colitis, and on inflammation-induced neoplasia. Based on this current knowledge,
a hypothesis is formulated about the mechanisms through which cigarette smoke interferes
with the gut in normal and pathological conditions.
Inflammatory Bowel Diseases (IBD) are complex multifactorial diseases characterized by an inappropriate host response to an altered commensal microbiome and dysfunctional mucus barrier. Cigarette smoking is the best known environmental risk factor in IBD. Here, we studied the influence of chronic smoke exposure on the gut microbiome and mucus layer composition in conventional mice. We compared smoke-exposed to air-exposed mice (n = 12) after a smoke exposure of 24 weeks. Both Illumina sequencing (n = 6) and denaturing gradient gel electrophoresis (DGGE) (n = 12) showed that bacterial activity and community structure were significantly altered in the colon due to smoke exposure. Interestingly, an increase of Lachnospiraceae sp. activity in the colon was observed. Also, changes in the mRNA expression Muc2 and Muc3 increased in the ileum, whereas Muc4 increased in the distal colon of smoke-exposed mice (n = 6). Furthermore, we observed increased Cxcl2 and decreased Ifn-γ in the ileum, and increased Il-6 and decreased Tgf-β in the proximal colon. Tight junction gene expression remained unchanged. We infer that the modulating role of chronic smoke exposure as a latently present risk factor in the gut may be driven by the altered epithelial mucus profiles and changes in microbiome composition and immune factors.
During the past decade, extensive research has undeniably improved the formulation and delivery of oral vaccines. Nevertheless, several factors, such as the harsh gastrointestinal environment together with tolerance induction to exogenous antigens, have thus far impeded the optimal effectiveness and clinical application of oral delivery systems. The current study encompasses an initial evaluation of the stability, biocompatibility, and cellular uptake of two promising candidate systems for oral antigen delivery, that is, calcium carbonate- (CP) and mannitol-templated (MP) porous microspheres. Both spray-dried formulations were efficiently internalized by human intestinal epithelial cells (Caco-2 and HT-29) and degraded into phagolysosomal intracellular compartments. In addition, cellular particle uptake and processing significantly up-regulated the expression of (HLA) class-II and costimulatory molecules on intestinal epithelial cells. Even though the high surface-area-to-volume ratio of the microspheres was expected to favor protease access, antigen release was remarkably limited in simulated intestinal fluid and was even absent under gastric conditions. Finally, neither CP nor MP exerted cytotoxicity upon prolonged in vitro incubation with high antigen concentration. Altogether, these data support the potential of CP and MP for oral antigen delivery and motivate the further development of these promising carrier systems in in vivo studies.
Oral vaccination is the most challenging vaccination method due to the administration route. However, oral vaccination has socio-economic benefits and provides the possibility of stimulating both humoral and cellular immune responses at systemic and mucosal sites. Despite the advantages of oral vaccination, only a limited number of oral vaccines are currently approved for human use. During the last decade, extensive research regarding antigen-based oral vaccination methods have improved immunogenicity and induced desired immunological outcomes. Nevertheless, several factors such as the harsh gastro-intestinal environment and oral tolerance impede the clinical application of oral delivery systems. To date, human clinical trials investigating the efficacy of these systems are still lacking. This review addresses the rationale and key biological and physicochemical aspects of oral vaccine design and highlights the use of yeast-derived β-glucan microparticles as an oral vaccine delivery platform.
Continuously improving the developmental process and the efficacy of oral vaccines is essential in the fight against intestinal pathogens. A promising strategy for vaccination applying safe, biodegradable and non-replicating antigen delivery systems has gained increased interest for eliciting cellular and humoral immune responses. The current study evaluates the potential of β-glucan particles (GP) as an oral antigen delivery system and their adjuvant characteristics. GP are efficiently internalized by human intestinal epithelial cell lines (Caco-2 and HT-29 cells), without exerting negative effects on cell viability. GP triggered the expression of pro-inflammatory cytokines IL-23p19, IL-8 and the β-glucan receptors dectin-1 and TLR2 by activated Caco-2 cells, and CCL20 in HT-29 cells. In contrast, the expression level of TGF-β, an important mediator of oral tolerance, was significantly downregulated in HT-29 cells. Additionally, adoptive transfer experiments showed proliferating ovalbumin (OVA)-specific CD4+ T cells mainly in the spleens of GP-OVA-fed mice. Furthermore, we detected a significantly increased IL-17 and a trend towards increased IFN-γ production in the spleen of GP-OVA-fed mice upon antigen restimulation. Oral administration of GP-OVA induced increased OVA-specific IgA, secretory-IgA (S-IgA) and secretory component (SC) production in intestinal fluids. Our data show that GP vehicles are able to deliver OVA via an oral route allowing efficient antigen presentation alongside adaptive immune activation, resulting in a Th17-biased response and the production of OVA-specific IgA, secretory-IgA and secretory component antibodies.
intestinal pathogens. A promising strategy for vaccination applying safe, biodegradable and non-replicating antigen
delivery systems has gained increased interest for eliciting cellular and humoral immune responses. The current
study evaluates the potential of β-glucan particles (GP) as an oral antigen delivery systemand their adjuvant characteristics.
GP are efficiently internalized by human intestinal epithelial cell lines (Caco-2 and HT-29 cells), without
exerting negative effects on cell viability. GP triggered the expression of pro-inflammatory cytokines IL-23p19, IL-8
and the β-glucan receptors dectin-1 and TLR2 by activated Caco-2 cells, and CCL20 in HT-29 cells. In contrast, the
expression level of TGF-β, an important mediator of oral tolerance, was significantly downregulated in HT-29 cells.
Additionally, adoptive transfer experiments showed proliferating ovalbumin (OVA)-specific CD4+T cells mainly in
the spleens of GP-OVA-fed mice. Furthermore, we detected a significantly increased IL-17 and a trend towards
increased IFN-γ production in the spleen of GP-OVA-fed mice upon antigen restimulation. Oral administration of
GP-OVA induced increased OVA-specific IgA, secretory-IgA (S-IgA) and secretory component (SC) production in intestinal
fluids. Our data show that GP vehicles are able to deliver OVA via an oral route allowing efficient antigen
presentation alongside adaptive immune activation, resulting in a Th17-biased response and the production of
OVA-specific IgA, secretory-IgA and secretory component antibodies.
Talks by Rebecca De Smet
such as Crohn’s disease (CD), spondyloarthritis (SpA) and chronic obstructive pulmonary
disease (COPD). Epidemiologic studies have shown that cigarette smoking (CS) is
a prominent common risk factor in these TNF-dependent diseases. We exposed TNFΔARE
mice; in which a systemic TNF-α overexpression leads to the development of inflammation;
to 2 or 4 weeks of air or CS. We investigated the effect of deregulated TNF expression on
CS-induced pulmonary inflammation and the effect of CS exposure on the initiation and progression
of gut and joint inflammation. Upon 2 weeks of CS exposure, inflammation in lungs
of TNFΔARE mice was significantly aggravated. However, upon 4 weeks of CS-exposure,
this aggravation was no longer observed. TNFΔARE mice have no increases in CD4+ and
CD8+ T cells and a diminished neutrophil response in the lungs after 4 weeks of CS exposure.
In the gut and joints of TNFΔARE mice, 2 or 4 weeks of CS exposure did not modulate
the development of inflammation. In conclusion, CS exposure does not modulate gut and
joint inflammation in TNFΔARE mice. The lung responses towards CS in TNFΔARE mice however
depend on the duration of CS exposure.
factor in Crohn's disease while it positively interferes with the disease course of ulcerative colitis.
However, the underlying mechanisms through which smoking exerts this divergent effect and
affects pathogenesis of inflammatory bowel disease are largely unknown. Animal smoke models
are good models to investigate the impact of cigarette smoke on intestinal physiology and
inflammation. They enable one to explore the interaction of smoke components and the
gut on cellular and molecular level, clarifying how smoking interferes with normal gut function
and with disease course in inflammatory conditions. This review describes the currently
used animal models for studying the impact of cigarette smoke on the intestinal tract. We
first discuss the different methods for simulation of smoking. Furthermore, we focus on
the effect of smoke exposure on normal gut physiology and immunology, on experimental
(entero)colitis, and on inflammation-induced neoplasia. Based on this current knowledge,
a hypothesis is formulated about the mechanisms through which cigarette smoke interferes
with the gut in normal and pathological conditions.
Inflammatory Bowel Diseases (IBD) are complex multifactorial diseases characterized by an inappropriate host response to an altered commensal microbiome and dysfunctional mucus barrier. Cigarette smoking is the best known environmental risk factor in IBD. Here, we studied the influence of chronic smoke exposure on the gut microbiome and mucus layer composition in conventional mice. We compared smoke-exposed to air-exposed mice (n = 12) after a smoke exposure of 24 weeks. Both Illumina sequencing (n = 6) and denaturing gradient gel electrophoresis (DGGE) (n = 12) showed that bacterial activity and community structure were significantly altered in the colon due to smoke exposure. Interestingly, an increase of Lachnospiraceae sp. activity in the colon was observed. Also, changes in the mRNA expression Muc2 and Muc3 increased in the ileum, whereas Muc4 increased in the distal colon of smoke-exposed mice (n = 6). Furthermore, we observed increased Cxcl2 and decreased Ifn-γ in the ileum, and increased Il-6 and decreased Tgf-β in the proximal colon. Tight junction gene expression remained unchanged. We infer that the modulating role of chronic smoke exposure as a latently present risk factor in the gut may be driven by the altered epithelial mucus profiles and changes in microbiome composition and immune factors.
During the past decade, extensive research has undeniably improved the formulation and delivery of oral vaccines. Nevertheless, several factors, such as the harsh gastrointestinal environment together with tolerance induction to exogenous antigens, have thus far impeded the optimal effectiveness and clinical application of oral delivery systems. The current study encompasses an initial evaluation of the stability, biocompatibility, and cellular uptake of two promising candidate systems for oral antigen delivery, that is, calcium carbonate- (CP) and mannitol-templated (MP) porous microspheres. Both spray-dried formulations were efficiently internalized by human intestinal epithelial cells (Caco-2 and HT-29) and degraded into phagolysosomal intracellular compartments. In addition, cellular particle uptake and processing significantly up-regulated the expression of (HLA) class-II and costimulatory molecules on intestinal epithelial cells. Even though the high surface-area-to-volume ratio of the microspheres was expected to favor protease access, antigen release was remarkably limited in simulated intestinal fluid and was even absent under gastric conditions. Finally, neither CP nor MP exerted cytotoxicity upon prolonged in vitro incubation with high antigen concentration. Altogether, these data support the potential of CP and MP for oral antigen delivery and motivate the further development of these promising carrier systems in in vivo studies.
Oral vaccination is the most challenging vaccination method due to the administration route. However, oral vaccination has socio-economic benefits and provides the possibility of stimulating both humoral and cellular immune responses at systemic and mucosal sites. Despite the advantages of oral vaccination, only a limited number of oral vaccines are currently approved for human use. During the last decade, extensive research regarding antigen-based oral vaccination methods have improved immunogenicity and induced desired immunological outcomes. Nevertheless, several factors such as the harsh gastro-intestinal environment and oral tolerance impede the clinical application of oral delivery systems. To date, human clinical trials investigating the efficacy of these systems are still lacking. This review addresses the rationale and key biological and physicochemical aspects of oral vaccine design and highlights the use of yeast-derived β-glucan microparticles as an oral vaccine delivery platform.
Continuously improving the developmental process and the efficacy of oral vaccines is essential in the fight against intestinal pathogens. A promising strategy for vaccination applying safe, biodegradable and non-replicating antigen delivery systems has gained increased interest for eliciting cellular and humoral immune responses. The current study evaluates the potential of β-glucan particles (GP) as an oral antigen delivery system and their adjuvant characteristics. GP are efficiently internalized by human intestinal epithelial cell lines (Caco-2 and HT-29 cells), without exerting negative effects on cell viability. GP triggered the expression of pro-inflammatory cytokines IL-23p19, IL-8 and the β-glucan receptors dectin-1 and TLR2 by activated Caco-2 cells, and CCL20 in HT-29 cells. In contrast, the expression level of TGF-β, an important mediator of oral tolerance, was significantly downregulated in HT-29 cells. Additionally, adoptive transfer experiments showed proliferating ovalbumin (OVA)-specific CD4+ T cells mainly in the spleens of GP-OVA-fed mice. Furthermore, we detected a significantly increased IL-17 and a trend towards increased IFN-γ production in the spleen of GP-OVA-fed mice upon antigen restimulation. Oral administration of GP-OVA induced increased OVA-specific IgA, secretory-IgA (S-IgA) and secretory component (SC) production in intestinal fluids. Our data show that GP vehicles are able to deliver OVA via an oral route allowing efficient antigen presentation alongside adaptive immune activation, resulting in a Th17-biased response and the production of OVA-specific IgA, secretory-IgA and secretory component antibodies.
intestinal pathogens. A promising strategy for vaccination applying safe, biodegradable and non-replicating antigen
delivery systems has gained increased interest for eliciting cellular and humoral immune responses. The current
study evaluates the potential of β-glucan particles (GP) as an oral antigen delivery systemand their adjuvant characteristics.
GP are efficiently internalized by human intestinal epithelial cell lines (Caco-2 and HT-29 cells), without
exerting negative effects on cell viability. GP triggered the expression of pro-inflammatory cytokines IL-23p19, IL-8
and the β-glucan receptors dectin-1 and TLR2 by activated Caco-2 cells, and CCL20 in HT-29 cells. In contrast, the
expression level of TGF-β, an important mediator of oral tolerance, was significantly downregulated in HT-29 cells.
Additionally, adoptive transfer experiments showed proliferating ovalbumin (OVA)-specific CD4+T cells mainly in
the spleens of GP-OVA-fed mice. Furthermore, we detected a significantly increased IL-17 and a trend towards
increased IFN-γ production in the spleen of GP-OVA-fed mice upon antigen restimulation. Oral administration of
GP-OVA induced increased OVA-specific IgA, secretory-IgA (S-IgA) and secretory component (SC) production in intestinal
fluids. Our data show that GP vehicles are able to deliver OVA via an oral route allowing efficient antigen
presentation alongside adaptive immune activation, resulting in a Th17-biased response and the production of
OVA-specific IgA, secretory-IgA and secretory component antibodies.