Antibody production by administration of biodegradable granules incorporating antigen through different injection routes (original) (raw)
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Vaccine, 1999
Protein-loaded microparticles were produced from blends of poly(ethylene glycol) (PEG) with poly(L-lactide) (PLA) homopolymer or poly(DL-lactide co-glycolide) copolymers (PLG) using a water-in oil-in oil method. The stability of ovalbumin (OVA) associated with microparticles prepared using PEG and 50:50 PLG, 75:25 PLG and PLA, respectively, was analysed by SDS-PAGE and quanti®ed by scanning densitometry following incubation in PBS at 378C for up to 1 month. Fragmentation and aggregation of OVA was detected with all 3 formulations. The extent of both processes correlated with the degradation rate of the lactide polymer used and decreased in the order PLA < 75:25 PLG < 50:50 PLG. Extensive degradation of the PLG/PEG microparticles also occurred over 4 weeks whereas the use of PLA/PEG blends resulted in a stable microparticle morphology and much reduced fragmentation and aggregation of the associated protein. Following a single sub-cutaneous immunisation, high levels of speci®c serum IgG antibody were elicited by OVA associated with the PLA/PEG particles. Injection of OVA associated with the 75:25 PLG/PEG microparticles resulted in very low levels of speci®c antibody. A higher response was induced by the 50:50 PLG/PEG formulation but there was very large inter-animal variation in this group. Antibody levels elicited by all 3 formulations were signi®cantly higher than those elicited by a single injection of soluble OVA. Analysis of antigen speci®c IgG1 and IgG2a antibody subtype levels also revealed the greater ecacy of the PLA/PEG microparticles as an adjuvant system. The use of PLA/PEG microparticles shows improved protein loading and delivery capacity while maintaining a high level of stability of the associated protein. These results indicate a strong correlation between the stability of microencapsulated antigen and the magnitude of the immune response following sub-cutaneous immunisation.
Polyelectrolyte LbL microcapsules versus PLGA microparticles for immunization with a protein antigen
Journal of Controlled Release
The transition from organism-based traditional vaccines to the use of safer subunit vaccines has implemented the use of adjuvants to enhance immunogenicity. This study compares the potential of two types of polymeric microparticles as delivery systems for the model antigen ovalbumin. The delivery systems encompassed polyelectrolyte microcapsules, assembled via Layer-by-Layer technology, and PLGA microparticles fabricated by spray-drying. Mice were immunized subcutaneously either by a single injection or by two injections separated by four weeks with an equivalent dose of the OVA-loaded particles. Both particulate formulations mediated high, long-term IgG 1 responses whereas the IgG 2c titers remained low. Additionally, Th1 and Th2 phenotype immune responses against OVA were assessed by quantifying the production of cytokines in CD4 + T-cells derived from the spleens of immunized mice at 6 months after the first injection. Immunization with particulate formulations led to significantly increased IL-2, IL-4, IL-10 and IFN-γ production by splenic CD4 + T-cells compared to control animals. LbL microcapsules and PLGA microparticles generated strong immune responses in vivo, characterized by a mixed Th1/Th2 type response with predominance of Th2 immunity. Both particulate formulations elicited a comparable type of immune response and appear to be promising for antigen delivery.
Vaccine, 2003
The immunogenicity of proteins encapsulated in poly(dl-lactide-co-glycolide) (PLG) microspheres has not been investigated to any extent in large animal models. In this study, IgG and IgA responses to ovalbumin (OVA), encapsulated in microspheres was investigated following intranasal inoculation into calves. Scanning electron microscopy and flow cytometric analysis demonstrated a uniform microsphere population with a diameter of <2.5 m. Ovalbumin was released steadily from particles stored in PBS almost in a linear fashion, and after 4 weeks many particles showed cracks and fissures in their surface structure. Following intranasal inoculation of calves with different doses of encapsulated antigen, mean levels of ovalbumin-specific IgA were observed to increase steadily but significant differences in IgA levels (from the pre-inoculation level) were only observed following a second intranasal inoculation. With 0.5 and 1.0 mg doses of antigen, ovalbumin-specific IgG was also detected in serum. Ovalbumin-specific IgA persisted in nasal secretions for a considerable period of time and were still detectable in four out of seven animals, 6 months after inoculation.
Size effect on the antibody production induced by biodegradable microspheres containing antigen
Vaccine, 1996
Poly(L-lactic acid) (PLLA) microspheres containing a model antigen, ovalbumin (OVA), were prepared by the evaporation method using double emulsion, and fractionated into dtflerent sizes by counterflow elutriation. Following the intraperitoneal (i.p.) and subcutaneous (s.c.) injection of the microspheres to mice, the titer of anti-OVA antibody in the serum was measured to assess the size eflect on the proJile of antibody production, OVA was released from the microspheres for 80 days, irrespective of the microsphere size. In both the XC. and i,p. immunization, the serum level of anti-OVA IgG antibody in the mice induced by the microspheres containing OVA was higher than that of free OVA when compared at the same dose. The serum level of antibody in the mice i.p. injected with the microspheres tended to increase with the decreasing size. On the other hand, in the S.C. immunization, the microsphere size had little influence on the antibody production. It is possible that the injected microspheres tend to aggregate in the S.C. tissue, disappearing the size eflect on the antibody production. Since the amount of microspheres injected increases with the decreasing size when their OVA loading is fixed, the increase in the amount will promote the interaction with immune cells, resulting in an enhanced antibody production. The cell interaction with the microspheres in the peritoneal cavity seems to be influenced by their size to a greater extent than in the S.C. tissue, probably because of their more frequent interaction with immune cells.
Enhanced secretory IgA and systemic IgG after oral immunization with biodegradable microparticles
Immunology
Intragastric immunization may lead to the induction of antibodies in the secretory immune system including saliva. The antibody response is usually short-lived. The objectives of this study were to see whether oral immunization with biodegradable microparticles containing antigen might lead to enhanced mucosal responses. Ovalbumin (OVA) was entrapped in a novel antigen delivery system comprising poly (D,L-lactide-co-glycolide) (PLGA) microparticles. Salivary IgA and serum IgG responses after three daily oral immunizations in BALB/c mice were assayed by ELISA at weekly intervals and compared with those to soluble antigen. Low levels of salivary IgA antibodies were detected at Weeks 2 and 3 in both groups and no significant differences were found. After a secondary series of intragastric immunizations at Week 4, marked differences were apparent between the groups. The mean salivary IgA titre at Week 6 was 959 + 494 U compared with 30 + 5 in the soluble OVA group (P < 000001). Significant differences were still apparent at Weeks 7-8 though the value was falling. Serum IgG antibodies were detectable and were significantly greater in the particle group (at Weeks 4 and 8) than in controls (P < 0.001). These results suggest that microparticles are taken up by antigen-presenting cells in Peyer's patches, then slowly degrade in vivo and release entrapped antigens, and thus can function as potent antigen delivery systems giving rise to both mucosal and systemic responses. Microparticles have considerable potential as a controlled released antigen delivery system for the induction of longer-term immune responses at mucosal surfaces.
2016
Oral delivery system has numerous advantages; however some peptide and protein drugs may occurs degradation by gastrointestinal enzyme when given orally. Ca-alginate microspheres containing model antigen Ovalbumin were prepared to protect ovalbumin from degradation by forming microspheres to enhance immune response and uptake of microspheres by lymphoid tissue in mice’s intestine. Ovalbumin-alginate microspheres were produced by aerosolization technique using Na-alginate polymer and CaCl2 cross-linker. To increase stability during storage, microspheres were dried with 5% maltodextrin as lyoprotectant. To observe immunological evaluation, hemagglutination test by measuring antibody titre was conducted for all groups compared to vaccine product which administered via intra muscular route. In vivo uptake study of microsphere in mice’s villi and Peyer’s patches at different time series were performed by labelling microspheres with rhodamine B. IgG titre immune response of Ca-alginate mi...
Biodegradable microparticles as oral vaccines
Advances in Experimental Medicine and Biology, 1995
A model but poor immunogen, ovalbumin (OVA), was entrapped in a novel antigen delivery system comprising poly (D,L-lactide-co-glycolide) (PLGA) microparticles. Both the primary and the secondary IgG antibody responses obtained with OVA in microparticles were compared to those obtained with OVA emulsified in Freunds' adjuvants by two routes of immunization, intraperitoneal (i.p.) and subcutaneous (s.c.) injection. Following single i.p. or s.c. injections, the IgG serum antibody responses to OVA in microparticles were significantly greater than the responses to OVA in Freunds' complete adjuvant (FCA) for up to 10 weeks. After s.c. booster doses of OVA, the secondary IgG antibody responses to OVA in microparticles remained greater than the secondary responses to OVA in Freunds', but not significantly so. Furthermore, the primary IgG responses to OVA in microparticles obtained 8-12 weeks after a single i.p. injection were greater than the secondary responses to OVA in Freunds' obtained by repeat s.c. injections at Weeks 0 and 6. These results demonstrate that microparticles can function as potent antigen delivery systems for an entrapped antigen. Due to their ability to degrade slowly in vivo and to release entrapped antigens, microparticles have considerable potential as controlled release antigen delivery systems for the induction of long-term immune responses.
Vaccine, 1996
Induction of systemic and mucosal immune responses following oral administration of biodegradable poly(D,L-lactic acid) (PDLLA) microspheres containing a model antigen, ovalbunin (OVA) was studied using microspheres with different average diameters of 0.6, 1.0, 4.0, 7.0, 11.0, 15.0, 21.0, and 26.0 microns. They were prepared from double emulsion with the solvent evaporation method, followed by size fractionation on counterflow elutriation. OVA was released from the microspheres in vitro over 80 days, irrespective of their size. Production of the serum anti-OVA IgG antibody and secretory OVA-specific IgA antibody in the mice gut was assessed following the oral administration of PDLLA microspheres containing OVA. Microspheres with a diameter of 4.0 microns enhanced the serum antibody in contrast with that of free OVA, but were not effective in inducing the gut secretion of IgA antibody. On the other hand, OVA-containing microspheres with a diameter of 7.0 microns enhanced IgA secretio...
Clinical & Experimental Allergy, 2007
Background Despite immunotherapy has been reported as the only treatment able to revert the Th2 response, its administration has some disadvantages such as the requirement of multiple doses, possible side effects provoked by conventional adjuvants and the risk of suffering an anaphylactic shock. For that reasons, drug delivery systems appear to be a promising strategy due to its ability to i) transport the allergens, ii) protect them from degradation, iii) decrease the number of administrations and iv) act as immuno-adjuvants.
Clinical and Experimental Allergy, 2007
Background Despite immunotherapy has been reported as the only treatment able to revert the Th2 response, its administration has some disadvantages such as the requirement of multiple doses, possible side effects provoked by conventional adjuvants and the risk of suffering an anaphylactic shock. For that reasons, drug delivery systems appear to be a promising strategy due to its ability to i) transport the allergens, ii) protect them from degradation, iii) decrease the number of administrations and iv) act as immuno-adjuvants. Objective The aim of this work was to evaluate the properties of poly-caprolactone (PCL) microparticles as adjuvants in immunotherapy using ovalbumin (OVA) as allergen model. For this purpose, the protection capacity of these microparticles (OVA PCL) against OVA allergy was studied in a murine model. Methods The humoral and cellular induced immune response generated by OVA encapsulated into PCL microparticles was studied immunizing BALB/c mice intradermically. Beside, OVAsensitized mice were treated with OVA PCL and OVA adsorbed to aluminium hydroxide (OVA-Alum). Fifteen days after therapy, animals were challenged with OVA and different signs of anaphylactic shock were evaluated. Results One single shot by intradermal route with OVA PCL resulted in a Th2-type immune response. In OVA-sensitized mice, treatment with OVA PCL treatment elicited high OVA specific IgG but low levels of IgE. Furthermore, OVA PCL mice group displayed lower levels of serum histamine and higher survival rate in comparison with the positive control group. Conclusion The anaphylactic shock suffered by OVA PCL treated mice was weaker than the one induced in the OVA-Alum group. Hence, the intradermal immunization with OVA PCL microparticles induced hyposensitization in OVA-allergic mice.