NLRP3 Regulates IL-4 Expression in TOX+ CD4+ T Cells of Cutaneous T Cell Lymphoma to Potentially Promote Disease Progression

In cutaneous T cell lymphoma (CTCL), a dominant Th2 profile associated with disease progression has been proposed. Moreover, although the production and regulation of IL-4 expression during the early stages of the disease may have important implications in later stages, these processes are poorly understood. Here, we demonstrate the presence of TOX⁺ CD4⁺ T cells that produce IL-4⁺ in early-stage skin lesions of CTCL patients and reveal a complex mechanism by which the NLRP3 receptor promotes a Th2 response by controlling IL-4 production. Unassembled NLRP3 is able to translocate to the nucleus of malignant CD4⁺ T cells, where it binds to the human il-4 promoter. Accordingly, IL-4 expression is decreased by knocking down and increased by promoting the nuclear localization of NLRP3. We describe a positive feedback loop in which IL-4 inhibits NLRP3 inflammasome assembly, thereby further increasing its production. IL-4 induced a potentially malignant phenotype measured based on TOX expression and proliferation. This mechanism of IL-4 regulation mediated by NLRP3 is amplified in late-stage CTCL associated with disease progression. These results indicate that NLRP3 might be a key regulator of IL-4 expression in TOX⁺ CD4⁺ T cells of CTCL patients and that this mechanism might have important implications in the progression of the disease.

Vimentin antibody production in transplant patients and immunomodulatory effects of vimentin in-vitro

We investigated the presence of antibodies to vimentin in 150 patients awaiting transplant, (50 kidney, 50 liver and 50 thoracic) and in 51 previously transplanted kidney patients whose grafts had failed. Patients with primary end stage thoracic or kidney disease did not have increased levels of vimentin antibodies, but those with primary liver failure and those with kidney graft failure did. Those with kidney graft failure were more likely to form vimentin antibodies if the patient was HLA-DQ2 positive (p=<0.001). Further to this, we observed antibody mediated rejection in five HLA-DQ2 positive re-transplant patients where no other antibodies were identified. We investigated the effects of vimentin protein on cytokine production in phytohaemagglutinin stimulated and unstimulated peripheral blood mononuclear cells. When exposed to vimentin at low levels there was increased production of IL-10. When cultures were stimulated, there was a decrease in IL-10, IL-2 and IFN-gamma production and a large increase in IL-4 production (p=0.028) compared to the controls. These results suggest that under normal conditions exposure to vimentin can lead to regulation of the immune response. However, if the immune system is active, exposure to vimentin can enhance Th-2 immunity.