title: Poly(d,l)-lactide-co-glycolide (PLGA) microspheres as immunoadjuvant for Brugia malayi antigens.
abstract: Recently we identified in Brugia malayi adult worm extract (BmA) a pro-inflammatory 54-68kDa SDS-PAGE resolved fraction F6 that protects the host from the parasite via Th1/Th2 type responses. We are currently investigating F6 as a potential source of vaccine candidate(s) and the present study is aimed at investigating the suitability of poly(d,l)-lactide-co-glycolide microspheres (PLGA-Ms) as immunoadjuvant for the antigen administration in a single dose. PLGA-Ms were prepared aseptically by a modified double emulsion (w/o/w) solvent evaporation technique and their size, shape, antigen adsorption efficiency, in-process stability, and antigen release were characterized. Swiss mice were immunized by a single subcutaneous administration of BmA and F6 adsorbed on PLGA-Ms (lactide:glycolide ratios 50:50 and 75:25) and the immune responses were compared with administration of 1 or 2 doses of plain BmA and F6. Specific IgG, IgG1, IgG2a, IgG2b, IgE levels in serum, cellular-proliferative response and release of IFN-γ, TNF-α and nitric oxide from the cells of immunized host in response to the antigens/LPS/Con A challenge and antibody-dependant cellular cytotoxicity (ADCC) to parasite life stages were determined. The average size of PLGA-Ms 50:50 was smaller than the size of PLGA-Ms 75:25 and the % antigen adsorption efficiency of PLGA-Ms 50:50 was greater than PLGA-Ms 75:25. Single shot injection of PLGA-Ms 50:50/75:25-BmA/F6 produced better and stronger IgG, IgG1/IgG2a and cell-mediated immune responses than even two injections of plain BmA or F6. Further, PLGA-Ms 50:50-F6 produced stronger responses than PLGA-Ms 50:50-BmA. Anti-PLGA-Ms 50:50-F6 antibodies elicited higher ADCC response to infective larval and microfilarial stages of the parasite than anti-PLGA-Ms 75:25-F6 antibodies. The findings demonstrate that PLGA-Ms 50:50 is an excellent adjuvant for use with F6 in a single administration. This is the first ever report on PLGA as immunoadjuvant for filarial antigens.
authors.affiliation: Department of Pharmaceutical Sciences, School of Engineering and Technology, Dr. Harisingh Gour Central University, Sagar 470003, MP, India.
authors.forename: Vinay
authors.initials: V
authors.lastname: Saini
authors.forename: Shiv Kumar
authors.initials: SK
authors.lastname: Verma
authors.forename: P Kalpana
authors.initials: PK
authors.lastname: Murthy
authors.forename: Dharmveer
authors.initials: D
authors.lastname: Kohli
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage* / Q000737:chemistry; D000818:Animals; D000953:Antigens, Protozoan / Q000737:chemistry* / Q000276:immunology; D017178:Brugia malayi / Q000276:immunology*; D049109:Cell Proliferation / Q000187:drug effects; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007371:Interferon-gamma / Q000378:metabolism; D019344:Lactic Acid / Q000737:chemistry / Q000276:immunology*; D008297:Male; D051379:Mice; D008863:Microspheres; D009569:Nitric Oxide / Q000378:metabolism; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D016052:Protozoan Vaccines / Q000008:administration & dosage* / Q000276:immunology / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000276:Adjuvants, Immunologic; D000953:Antigens, Protozoan; D007074:Immunoglobulin G; D016052:Protozoan Vaccines; D014409:Tumor Necrosis Factor-alpha; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D009569:Nitric Oxide; D019344:Lactic Acid; D007073:Immunoglobulin E; D007371:Interferon-gamma
keywords: ADCC; Brugia malayi; Immunoglobulins; Lymphocyte transformation test; Nitric oxide; PLGA microspheres; Th1 cytokines