Table 1_Immunization with detoxified TNFα elicits neutralizing antibodies and ameliorates inflammatory shock and autoimmune arthritis in mice.docx

IntroductionTumor necrosis factor-⍺ (TNF⍺) is central to the pathogenesis of autoimmune and inflammatory diseases, and monoclonal antibody-based TNF⍺ inhibitors are amongst the most used biologics worldwide. As an alternative to exogenously administered antibodies, active immunization has been explored as a TNF⍺ neutralization strategy.
MethodsWe generated a murine TNF⍺ (mTNF⍺) Y87S point mutant expressed in E. coli that preserved the native trimeric structure while abrogating receptor binding. Using histidine-tag interactions, the antigen was displayed on the surface of immunogenic cobalt porphyrin-phospholipid (CoPoP) liposomes, which further attenuated TNF⍺ toxicity and enabled safe immunization. Immunization and protective efficacy were evaluated in murine models, including lipopolysaccharide/galactosamine-induced lethal shock and collagen-induced arthritis (CIA). Parallel studies were conducted with a similarly engineered human TNF⍺ (hTNF⍺) Y87S mutant.
ResultsLiposome display of TNF⍺ elicited significantly higher levels of neutralizing antibodies following immunization. In mice, immunization improved survival in the lethal shock model and ameliorated clinical symptoms and joint inflammation in the CIA model. The Y87S mutation similarly detoxified hTNF⍺ constructs, which could also be effectively displayed on CoPoP liposomes. Immunization with hTNF⍺ induced high-titer anti-TNF⍺ IgG and serum neutralizing activity superior to other adjuvants.
DiscussionThese findings demonstrate that CoPoP-based TNF⍺ point mutant vaccines can safely induce high levels of functional TNF⍺-neutralizing antibodies. This strategy represents a potential low-cost alternative to current TNF-blocking biologics for the treatment of autoimmune diseases.