Inverse-Vaccines for Rheumatoid Arthritis Re-establish Metabolic and Immunological Homeostasis in Joint Tissues

Rheumatoid arthritis (RA) causes immunological and metabolic imbalances in tissue, exacerbating inflammation in affected joints. Changes in immunological and metabolic tissue homeostasis at different stages of RA are not well understood. Herein, the changes in the immunological and metabolic profiles in different stages in collagen induced arthritis (CIA), namely, early, intermediate, and late stage is examined. Moreover, the efficacy of the inverse-vaccine, paKG(PFK15+bc2) microparticle, to restore tissue homeostasis at different stages is also investigated. Immunological analyses of inverse-vaccine-treated group revealed a significant decrease in the activation of pro-inflammatory immune cells and remarkable increase in regulatory T-cell populations in the intermediate and late stages compared to no treatment. Also, glycolysis in the spleen is normalized in the late stages of CIA in inverse-vaccine-treated mice, which is similar to no-disease tissues. Metabolomics analyses revealed that metabolites UDP-glucuronic acid and L-Glutathione oxidized are significantly altered between treatment groups, and thus might provide new druggable targets for RA treatment. Flux metabolic modeling identified amino acid and carnitine pathways as the central pathways affected in arthritic tissue with CIA progression. Overall, this study shows that the inverse-vaccines initiate early re-establishment of homeostasis, which persists through the disease span.

Exponentially decreasing exposure of antigen generates anti-inflammatory T-cell responses

Rheumatoid Arthritis (RA) is a chronic debilitating disease characterized by auto-immune reaction towards self-antigen such as collagen type II. In this study, we investigated the impact of exponentially decreasing levels of antigen exposure on pro-inflammatory T cell responses in the collagen-induced arthritis (CIA) mouse model. Using a controlled delivery experimental approach, we manipulated the collagen type II (CII) antigen concentration presented to the immune system. We observed that exponentially decreasing levels of antigen generated reduced pro-inflammatory T cell responses in secondary lymphoid organs in mice suffering from RA. Specifically, untreated mice exhibited robust pro-inflammatory T cell activation and increased paw inflammation, whereas, mice exposed to exponentially decreasing concentrations of CII demonstrated significantly reduced pro-inflammatory T cell responses, exhibited lower levels of paw inflammation, and decreased arthritis scores in right rear paw. The data also demonstrate that the decreasing antigen levels promoted the induction of regulatory T cells (Tregs), which play a crucial role in maintaining immune tolerance and suppressing excessive inflammatory responses. Our findings highlight the importance of antigen concentration in modulating pro-inflammatory T cell responses in the CIA model. These results provide valuable insights into the potential therapeutic strategies that target antigen presentation to regulate immune responses and mitigate inflammation in rheumatoid arthritis and other autoimmune diseases. Further investigations are warranted to elucidate the specific mechanisms underlying the antigen concentration-dependent modulation of T cell responses and to explore the translational potential of this approach for the development of novel therapeutic interventions in autoimmune disorders.

Vaccines prevent reinduction of rheumatoid arthritis symptoms in collagen-induced arthritis mouse model

Metabolic reprogramming of immune cells modulates their function and reduces the severity of autoimmune diseases. However, the long-term effects of the metabolically reprogrammed cells, specifically in the case of immune flare-ups, need to be examined. Herein, a re-induction rheumatoid arthritis (RA) mouse model was developed by injecting T-cells from RA mice into drug-treated mice to recapitulate the effects of T-cell-mediated inflammation and mimic immune flare-ups. Immune metabolic modulator paKG(PFK15 + bc2) microparticles (MPs) were shown to reduce clinical symptoms of RA in collagen-induced arthritis (CIA) mice. Upon re-induction, a significant delay in the reappearance of clinical symptoms in the paKG(PFK15 + bc2) microparticle treatment group was observed as compared to equal or higher doses of the clinically utilized U.S. Food and Drug Administration (FDA)-approved drug, Methotrexate (MTX). Furthermore, paKG(PFK15 + bc2) microparticle-treated mice were able to lower activated dendritic cells (DCs) and inflammatory T helper cell 1 (TH1) and increased activated, proliferating regulatory T-cells (Tregs) more effectively than MTX. The paKG(PFK15 + bc2) microparticles also led to a significant reduction in paw inflammation in mice as compared to MTX treatment. This study can pave the way for the development of flare-up mouse models and antigen-specific drug treatments.