A simple method for producing a monospecific antiserum against IgM

Immunoprophylaxis of multi-antigen peptide (MAP) vaccine for human lymphatic filariasis

Human lymphatic filariasis, the parasitic disease caused by the filarial nematodes Wuchereria bancrofti, Brugia malayi, and Brugia timori, is ranked as the second most complex clinical condition leading to permanent and long-term disability. The multiple antigen peptide (MAP) approach is an effective method to chemically synthesize and deliver multiple T and B cell epitopes as the constituents of a single immunogen. Here, we report on the design, chemical synthesis, and immunoprophylaxis of three epitopes that have been identified from promising vaccine candidates reported in our previous studies, constructed as MAP on an inert lysine core for human lymphatic filariasis in Jird model. Two epitopes from Thioredoxin and one epitope from Transglutaminase were constructed as MAP in an inert lysine core. The immunoprophylaxis of the synthetic vaccine construct studied in Jird models showed protective antibody (1 in 64,000 titer) and cellular immune response. Thioredoxin-Transglutaminase MAP (TT MAP) conferred a significantly high protection of 63.04% compared to control (8.5%). Multi-antigen peptide vaccine is one best approach to provide immunity against multiple antigens delivered by the complex filarial parasite.

The adjuvant-free immunoprotection of recombinant filarial protein Abundant Larval Transcript-2 (ALT-2) in Mastomys coucha and the immunoprophylactic importance of its putative signal sequence

The filarial protein Abundant Larval Transcript-2 (ALT-2) of the filarial parasite Brugia malayi has been shown to produce 74% worm clearance when administered with an adjuvant. In the present study, we show that it not only induces humoral and cell-mediated immunity, but also protection up to 71% in Mastomys coucha, a permissive animal model for filariasis, even without adjuvant. This unique feature of ALT-2 protein is highly restricted to its 21 amino acid N-terminal signal sequence, the absence of which resulted in poor immune response as well as immunoprotection (49%). Moreover, ALT-2 is likely to exert immunoprotection effects in B. malayi infection by maintaining a Th1-Th2 balance, evident from higher levels of IgG1 and IgG2a as well as IL-4 and IFN-γ. An improved understanding about the role of this filarial protein in host immunity, host-parasite interaction and worm clearance will aid in the development of good immunoprophylaxis for the disease.

Preparation of antisera to the mu chain of IgM

The protein fraction in the first peak obtained by Sephadex G-200 gel filtration of normal bovine serum was reduced with 2-mercaptoethanol, alkylated with iodoactamide and recycled on a Sephadex G-200 column. The resultant chromatogram indicated the presence of two peaks the second of which was found to be pure monomeric IgM. Immunization of rabbits with the second peak protein resulted in the production of an antiserum with both heavy and light-chain activity. The light-chain activity was simply removed by absorption of the antiserum with glutaraldehyde-polymerized material obtained from the second peak of the initial Sephadex G-200 eluate, yielding an antiserum monospecific for the heavy chain of the IgM molecule.