T-cell clones from Th1, Th17 or Th1/17 lineages and their signature cytokines have different capacity to activate endothelial cells or synoviocytes.

•T-cells interact sequentially first with endothelial cells then with mesenchymal cells during the immune response.•Th1 cells are potent activators of endothelial cells.•Fibroblasts secrete pro-inflammatory factors in response to T-cell stimulation.•IL-17 is the main cytokine involved in Th17- and Th1/17-related inflammation.