Management of early inflammatory arthritis. Intervention with immunomodulatory agents: T cell vaccination

T-cell vaccination leads to suppression of intrapancreatic Th17 cells through Stat3-mediated RORγt inhibition in autoimmune diabetes

Immunization with inactivated autoreactive T cells is an effective therapeutic approach to ameliorating autoimmune diseases, while the underlying mechanisms that regulate autoreactive T cells are not completely understood. This study tested the hypothesis that T-cell vaccination (TCV) inhibits autoimmune diabetes in mice through the suppression of Th17 cells. The results showed that TCV treatment decreased hyperglycemia in type 1 diabetes (T1D) induced by multiple low-dose streptozotocin (MLD-STZ) as compared with the controls, preserved the number of healthy pancreatic islets and increased the production of insulin in the islets. Further study revealed that TCV significantly decreased the production of both interleukin (IL)-17 and IL-23 in intrapancreatic infiltrating lymphocytes (IPL) through marked inhibition of mRNA level of retinoic acid-related orphan receptor γt (RORγt) and signal transducer and activator of transcription 3 (Stat3) phosphorylation. The role of TCV-induced Th17 suppression was further validated in adoptive transfer experiments with polarized Th17 cells in sub-diabetogenic mice, which was similar to the effect of anti-IL-17 antibody treatment. Collectively our study shows that intrapancreatic Th17 cell suppression and healthy islet preservation play an important role in the treatment of T1D by TCV.

TCR vaccination in aluminum adjuvant protects against autoimmune encephalomyelitis

Experimental Allergic Encephalomyelitis (EAE) is a neuroinflammatory, autoimmune disorder in which myelin-reactive Th1 T cells with a restricted TCRVbeta repertoire play a pathogenic role. Here, I show that an engineered single-chain TCR containing dominant TCRValpha/Vbeta encephalitogenic elements, when administered in aluminum adjuvant, generates a marked anti-TCR humoral response that correlated with protection against the development of EAE in Vbeta8-expressing B10.PL but not in Vbeta8-deficient SJL mice. sc-TCR/Al vaccination was highly efficient in preventing murine EAE in a TCR-specific manner through a mechanism involving anti-TCR B cells and/or antibodies. Collectively, these data have important implications for designing preventive or therapeutic strategies combining TCR vaccination with the use of aluminum adjuvant in the treatment of multiple sclerosis and other human autoimmune inflammatory diseases.

The effect of VAS972 on allergic contact hypersensitivity

BACKGROUND

Contact hypersensitivity (CHS) is a Th1-mediated immune response that can be down-regulated by immunosuppressive agents such as cyclosporine and environmental stimuli such as ultraviolet light. Recently, an immunomodulation therapy, VAS972, has been developed which is believed to down-regulate the Th1 arm of the immune response. This VAS972 involves modifying autologous blood by controlled exposure to the oxidizing agent ozone and UVC light, at an elevated temperature ex vivo. The processed blood is then administered by intramuscular injection.

OBJECTIVE

To further evaluate the immune modulating effect of VAS972.

METHODS

We examined the effect of VAS972 treatment on CHS. Contact hypersensitivity was induced with dinitrofluorobenzene (DNFB) in animals receiving VAS972- processed blood, control blood, or saline. A preliminary study was also conducted to evaluate the effect of plasma and cellular fractions of processed blood.

RESULTS

Mice injected with VAS972-processed blood demonstrated a significantly lower (46%) CHS response than controls. Histologic examination of challenged ear skin from control mice displayed edema with a significant lymphocytic infiltration, whereas animals administered processed blood demonstrated a reduction in lymphocytic infiltration. Mice injected with either plasma or the cellular fraction of the VAS972-treated blood also demonstrated a significant suppression (49% and 41%, respectively).

CONCLUSION

The results of this study demonstrated that VAS972 suppresses CHS and cellular infiltration. Furthermore, the plasma and cellular components of the VAS972 treatment were also able to induce immunosuppression. This further supports the hypothesis that VAS972 down-regulates the Th1 arm of the immune response.

Prospects of immunotherapy for rheumatoid arthritis

The main challenge in the development of new modalities for the treatment of rheumatoid arthritis is to enhance the specificity while reducing the adverse side-effects of therapeutics. Biotechnology provides a variety of reagents, such as monoclonal antibodies, recombinant cytokines, cytokine antagonists, and small peptides, with the potential to interfere with selected stages of the disease process in a highly specific manner. In addition, several new therapeutic approaches have emerged as a result of extensive research with animal models of disease, including T-cell vaccination and bone marrow transplantation. This article discusses current insights into the pathogenesis of rheumatic diseases, focusing on rheumatoid arthritis. A number of new therapeutic modalities for rheumatoid arthritis, in particular those acting on the immune system, are discussed. Because it is not possible to provide a complete overview of all the developments in the field in limited space, a selection of strategies and modalities which are representative of the broad variety of immunotherapeutic approaches currently used are highlighted.