Interleukin-1β-Targeted Vaccine Improves Glucose Control and β-Cell Function in a Diabetic KK-Ay Mouse Model

Interleukin-1β (IL-1β) has been implicated as a key proinflammatory cytokine involved in the pancreatic islet inflammation of type 2 diabetes mellitus (T2DM). Excess IL-1β impairs islet function by inducing insulin resistance and β-cell apoptosis. Therefore, specifically reducing IL-1β activity provides a therapeutic improvement for T2DM by sustaining the inhibition of IL-1β-mediated islet inflammation. In this study, we developed an IL-1β-targeted epitope peptide vaccine adjuvanted with polylactic acid microparticles (1βEPP) and applied it to a diabetic KK-Ay mouse model. Results showed that the 1βEPP elicited high antibody responses, which neutralized the biological activity of IL-1β, and induced barely detectable inflammatory activity. 1βEPP immunization reduced body weight gain, protected KK-Ay mice from hyperglycemia, improved glucose tolerance and insulin sensitivity, and decreased the serum levels of free fatty acids, total cholesterol and triglyceride. Moreover, 1βEPP restored β-cell mass; inhibited β-cell apoptosis; decreased the expression of IL-1β; and interrupted NF-κB activation by reducing IKKβ and pRelA levels. These studies indicated that the IL-1β-targeted vaccine may be a promising immunotherapeutic for T2DM treatment.