Formulation and evaluation of oral microparticulate ovarian cancer vaccines.
ABSTRACT Ovarian cancer is the fifth most leading cause of cancer related deaths in women in the US. Customized immunotherapeutic strategies may serve as an alternative method to control the recurrence or progression of ovarian cancer and to avoid severe adverse effects of chemotherapy. In this study, a microparticulate vaccine using whole cell lysate of a murine ovarian cancer cell line, ID8 was prepared with the use of a spray dryer. These particles were designed for oral delivery using enteric polymers such as methacrylic copolymer, Eudragit(®) FS30D and hydroxyl propyl methyl cellulose acetate succinate. These particles were targeted for uptake via microfold cell (M-cell) in Peyer's patches of small intestine using M-cell targeting ligand, Aleuria aurantia lectin. The interleukins (ILs) such as IL-2 and IL-12 were added to the vaccine formulation to further enhance the immune response. The particles obtained were of 1.58±0.62 μm size with a charge of 12.48±2.32 mV. The vaccine efficacy was evaluated by administering the particles via oral route to C57BL/6 female mice. At the end of vaccination, mice were challenged with live tumor cells. Vaccinated mice showed significant (around six-fold) retardation of tumor volume in comparison to non-vaccinated animals for 3 weeks after the tumor challenge (p<0.001). The serum IgG antibody levels were found to be elevated in case of vaccinated animals in comparison to non-vaccinated group (p<0.05). Analysis of IgG1 titers (indicative of Th2 response) and IgG2a titers (indicative of Th1 response) showed a mixed Th1 and Th2 immune response in case vaccine alone and Th2 response in case of vaccine with interleukins group. Moreover, CD8+ T-cell, CD4+ T-cell and B-cell populations in different lymphatic organs were elevated in case of vaccinated mice. Thus, whole cell lysate vaccine microparticles formulated by spray drying could trigger humoral as well as cellular immune response when administered orally. Such vaccine could potentially be an effective treatment for patients with residual tumor or high tumor-relapse probability.
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ABSTRACT: Ovarian cancer is the fourth leading cause of cancer-related deaths among women and is among the least understood of all cancers. The objective of this study was to determine the effect of ovarian epithelial and stromal cell interaction in a mouse model of epithelial ovarian cancer (EOC) that closely resembled the human disease. A mouse model of EOC was generated by orthotopic injection of an ID8 mouse ovarian surface epithelial cell line (MOSEC) under the ovarian bursa of syngeneic mice and tissue was collected to evaluate factors contributing to the formation and development of ovarian tumors. By 90 days post-injection, mice were moribund and had developed large primary ovarian tumors, secondary tumors within the peritoneal cavity, and extensive ascites fluid production. Tumors were hypervascularized and were characterized as serous epithelial carcinomatosis, which replicates the most common form of human ovarian cancer. Cells isolated from ascites fluid were more proliferative with increased expression of survival factors compared to original MOSEC cells and cells obtained from the abdomen following intraperitoneal injection. Orthotopic injection of these cells under the ovarian bursa resulted in more aggressive tumorigenesis, with mice becoming moribund at 60 days post-injection compared with 90 days post-injection with the original ID8-MOSEC cell line. This study describes the generation of an orthotopic, syngeneic model of ovarian cancer, which replicates the phenotype of the human disease. Expression of angiogenic and proliferative factors, and the interaction of epithelial cells with the ovarian stroma are important factors in ovarian tumorigenesis.Gynecologic Oncology 03/2008; 108(2):385-94. · 3.69 Impact Factor
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ABSTRACT: Sperm protein (Sp17) is an attractive target for ovarian cancer (OC) vaccines because of its over-expression in primary as well as in metastatic lesions, at all stages of the disease. Our studies suggest that a Sp17-based vaccine can induce an enduring defense against OC development in C57BL/6 mice with ID8 cells, following prophylactic and therapeutic treatments. This is the first time that a mouse counterpart of a cancer testis antigen (Sp17) was shown to be expressed in an OC mouse model, and that vaccination against this antigen significantly controlled tumor growth. Our study shows that the CpG-adjuvated Sp17 vaccine overcomes the issue of immunologic tolerance, the major barrier to the development of effective immunotherapy for OC. Furthermore, this study provides a better understanding of OC biology by showing that Th-17 cells activation and contemporary immunosuppressive T-reg cells inhibition is required for vaccine efficacy. Taken together, these results indicate that prophylactic and therapeutic vaccinations can induce long-standing protection against OC and delay tumor growth, suggesting that this strategy may provide additional treatments of human OC and the prevention of disease onset in women with a family history of OC.PLoS ONE 05/2010; 5(5):e10471. · 3.53 Impact Factor
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ABSTRACT: Oral vaccination has long been regarded as the best alternative to conventional parenteral vaccination considering practical, economical, and immunological aspects. The purpose of this study was to develop albumin-chitosan mixed matrix microsphere-filled coated capsule formulations of Typhoid Vi antigen and to determine whether it can induce antigen-specific mucosal and systemic immune responses on oral administration. Formulations with Typhoid Vi antigen were prepared and filled into hard gelatin capsules (size # 9) and enteric coated. Formulations were characterized and administered to Sprague-Dawley rats to evaluate the induction of immune response to the antigen. The results indicated that the particle size, zeta potential, swelling, and disintegration rates were optimal for the oral delivery of microencapsulated vaccines. In vivo studies displayed multifold increase of antigen-specific IgG and IgA levels 8 weeks after oral immunization. No statistically significant difference in the antigen-specific IgG and IgA levels were found between oral and parenteral injection groups 8 weeks after vaccination. On the basis of the results of the study, it can be concluded that the oral administration of Typhoid Vi antigen microspheres was successful in inducing antigen-specific systemic and mucosal immune response.Journal of Drug Targeting 07/2009; 17(7):553-60. · 2.72 Impact Factor