seyed ali delbaz

Application of adjuvants with microbial origins is a recently highlighted approach in the vaccinology trials. Archaeosomes are among these microbial compounds with both adjuvant and liposomal activities and features. In the present study, recombinant HBsAg encapsulated into Methanobrevibacter smithii (M. smithii) archaeosomes. Balb/c mice immunized with this compound and humoral and cytokine secretion pattern of immunized models analyzed. Frequency of IFN-γ secreting cells in the HBsAg-containing archaeosomes group was significantly higher than HBsAg and HBsAg+C/IFA groups (p≤0.05). IgG2a titer in the sera of HBsAg-containing archaeosomes group was also significantly higher than this subclass titer in the other groups (p≤0.05). Analysis of induced responses revealed the Immunopotentiating characteristics of M. smithii archaeosomes in the induction of T-helper 1 responses according to the dominance of IgG2a subtype and IFN-γ secreting splenocytes of immunized mice.

Neisseria meningitidis Serogroup A, is a major cause of bacterial meningitidis outbreaks in Africa and the Middle East. While polysaccharide vaccines have been available for many years, these vaccines have many disadvantages including the induction of T-cell independent responses which do not induce memory responses.. Thus to overcome this problem, in this research outer membrane vesicle (OMV) containing PorA was extracted and evaluated by biological and immunological methods.. OMVs were extracted with deoxycholate and EDTA, and purification was performed by sequential ultracentrifugation. Physicochemical properties of extracted OMVs were analyzed by electron microscopy and SDS-PAGE. The toxicity of LPS content in its was assayed by LAL test. The Presence of PorA as a major component of OMV was confirmed by western blot. To study antibodies synthesis after immunization with OMV, ELISA method was used. Also serum bactericidal assay (SBA) was performed to determine the serum bactericidal activity against N.meningitidis serogroup A.. The results revealed that the content of protein extracted was 0.1mg/ml. The electron microscopy showed that intactness of the vesicle in these preparation ranged more than 70%. The SDS-PAGE showed that PorA as a major immunological part of outer membrane vesicle was located in 35-40kDa. LAL test showed that the endotoxin activity was around 126EU/ml which is safe for using. The ELISA test revealed that the IgG total titer was elevated after the first injection. SBA indicates that bactericidal antibodies rise after the second dose of booster.. The results showed that the extracted OMVs were conformationally stable, and there were no pyrogenic determinants in OMV. Also the results showed that the OMV elicited high level of specific antibodies against N. meningitidis serogroup A. These results indicate that the OMV obtained here, can be used as a meningococcal vaccine after further investigation..

Neisseria meningitidis serogroup A Polysaccharides vaccines have been available for many years, but these vaccines have many disadvantages due to their induction of T-Cell independent responses. To overcome these problems, many researches have been focused on other parts of bacterial cell component such as OMV (Outer membrane vesicle). In this study, OMV containing PorA were extracted and evaluated by biological and immunological methods.

OMV were extracted by siadat, et al method. Physicochemical properties of extracted OMV were analyzed by electron microscopy and SDS-page. The toxicity of LPS content in OMV was assayed by LAL test. The Presence of PorA was confirmed by western blot. Antibodies synthesis after immunization by OMV was evaluated using ELISA method.

The content of extracted protein was 0. mg/ml. Size of OMV was between 0 and 0 nanometer. SDS-PAGE showed that PorA was located in -0 kDa. LAL test showed that the endotoxin activity was ranged in 6EU/ml which is safe for using. The ELISA test showed that the total IgG titer was elevated after first injection.

The results showed that the conformation of extracted OMV was stable, and there were no progeny determinants in OMV. Also, OMV elicited high level of specific antibodies against Neisseria meningitidis serogroup A. These results indicate that the OMV can be used as a meningococcal vaccine after further investigations.