Abstract

PC:PE:CH LIPOSOMES AS STRONG IMMUNOMODULATORY ADJUVANT FOR ANTIGEN DELIVERY

Neeraj Jain*, Dharamveer Kohli and Neelam Jain

ABSTRACT

Objective: The present study was aimed on developing and characterizing Liposomal Delivery System loaded with antigen for achieving a better sustain release immunomodulating profile. Methods: Liposomes were prepared by Reverse Phase Evaporation (REV) method (Szoka and Papahadjopolus; 1978)[1] with slight modification using molar ratio of Soya PC:PE:Cholesterol in different molar concentration. Results: In the present study the storage stability of the vesicles was determined by measuring the vesicle size, residual antigen content and antigen integrity. Percent of residual antigen remain in liposomes by assuming the initial content to be 100%. The levels of F6 specific IgG1, IgG2a and IgG2b antibodies were found to be elevated in immunized animals over non-immunized controls. Analysis of IgG-subclasses revealed that all the subclasses at (1:25 dilution) increased several folds over the controls with IgG1 showing the greatest increase (25.0-fold) followed by IgG2b (3.0fold). Antibodies titers showed the many fold increment of titers on liposomised antigen groups (Gr.I; without booster dose and Gr.IV; with booster dose). IgG showed about 2.2 fold increment in Gr. IV than control group (Gr.V). IgG1 after booster dose showed about 25-fold increment followed by IgG2b than IgG2a. NO release from peritoneal macrophages of the animals (Gr.I, II, III, IV and V) was increased by exposure to LPS or no exposure to any stimulants in-vitro as compared to cells of non-immunized animals (Gr.V). In summary, F6 was able to induce greater NO production. The TNF-α release in cells of F6 immunized animals was elevated in response to F6, LPS or no stimulation in-vitro over non-immunized ones. Up-regulation in Th-I responses and down-regulation in Th-II responses show that the immunological cytokines were in function and cause triggers to body immunity to destroy the parasite. Conclusion: These results suggest that the liposomal antigen delivery system is a promising Immunomodulating carrier for antigen delivery and vaccine development.

Keywords: Antigen delivery, B. malayi, Soya PC:PE:CH liposomes, Th-1/Th-2 responses, Ig-G, Cytokines, IFN –?, TNF-?.