Aldehyde modification and alum coadjuvancy enhance anti‐TNF‐α autovaccination and mitigate arthritis in rat

Abstract

Experimental vaccination to induce antibodies (Abs) capable of cytokine antagonism shows promise as a novel immunotherapy for chronic inflammatory disease. We prepared a hybrid antigen consisting of residues 141-235 of rat TNF-α fused to the C-terminus of glutathione-S-transferase (GST), chemically modified to incorporate aldehyde residues, for development of an auto-vaccine eliciting anti-rTNF-α Abs. In rat immunization the soluble aldehyde-modified fusion protein did not generate observable Ab responses. By contrast, vaccination with the aldehyde-modified fusion protein adsorbed on alum induced anti-TNF-α autoAbs with high titer and neutralizing activity. Induction of adjuvant arthritis in rats pre-immunized with unmodified fusion protein or a control protein in alum resulted in severe inflammation and joint damage, whereas the disease induced in rats immunized with the aldehyde-bearing fusion protein in alum was markedly attenuated. Similar results were obtained in a collagen-induced rat arthritis model. Anti-collagen II IgG Ab titers did not deviate significantly in groups pre-immunized with modified fusion protein and control protein, suggesting that anti-TNF vaccination did not skew the immune response related to disease induction. This study demonstrates synergy between particulate alum and protein bound carbonyl residues for enhancement of protein immunogenicity. The antigen-specific co-adjuvant system could prove advantageous for breaking tolerance in emerging auto-vaccination therapies targeting inflammatory cytokines as well as for enhancing a broader category of subunit vaccines. Aldehyde adduction introduces a minimal modification which, together with the established use of alum as a safe adjuvant for human use, could be favorable for further vaccine development.

Active immunotherapy for TNF-mediated inflammation using self-assembled peptide nanofibers

“…Recently, several TNF-directed active immunotherapy strategies have been studied. These include recombinant TNF molecules engineered to contain exogenous CD4 + T helper epitopes [5, 6], TNF proteins containing unnatural amino acids [7], native TNF conjugated to carrier proteins such as keyhole limpet hemocyanin (KLH) or virus-like particles (VLPs) [8–11], Alum adjuvanted TNF epitope containing carrier proteins [12, 13], and DNA autovaccines against TNF [14]. Currently no active immunotherapy targeting TNF has been clinically approved.…”

Self-assembling peptides as immunomodulatory biomaterials

“…The main goal of active immunotherapy is to generate a predictable B cell response without an autoreactive T cell response (Jia et al, 2013). Researchers have used B cell epitopes from the targeted protein, non-autologous T-helper epitopes incorporated in a carrier protein, and if the response is insufficient, adjuvants are added (Durez et al, 2014;Bavoso et al, 2015;Zhang et al, 2016). A supramolecular peptide system was created with exogenous T-cell epitopes and TNF B cell epitopes co-assembled into a nanofiber without additional adjuvants (Mora-Solano et al, 2017).…”

Modular complement assemblies for mitigating inflammatory conditions

“…Active immunotherapy platforms under investigation have previously comprised conjugates of antigen to carrier proteins such as keyhole limpet hemocyanin (14) or virus-like particles (15,16) that provide exogenous T cell epitopes, facilitating the production of T-dependent immune responses (17). Many such platforms additionally require adjuvants to achieve a therapeutic response (18), which commonly induce some degree of inflammation and may not necessarily induce the desired T helper phenotype or antibody subclass/isotype (19).…”