Synthesis of Th17 cytokines in the culture of peripheral blood mononuclear cells stimulated with Borrelia burgdorferi sensu lato.

INTRODUCTION AND OBJECTIVE

Th17 lymphocytes and their cytokines, interleukin 17A (IL-17A), IL-17F and IL-22, participate in the response to extracellular bacteria and in the autoimmunity and may be engaged in the pathogenesis of Lyme borreliosis. Concentrations were measured of IL-17A, IL-17F and IL-22 in the supernatant of the peripheral blood mononuclear cells (PBMC) culture stimulated with Borrelia burgdorferi sensu lato (B. burgdorferi).

MATERIALS AND METHOD

The study group consisted of 13 patients with early disseminated and late Lyme borreliosis and a control group of 7 healthy persons. PBMC cultures were stimulated for 48 hours with B. burgdorferi spirochetes of three pathogenic species: B. burgdorferi sensu stricto, B. afzelii or B. garinii, in the multiplicity of infection 10:1. Concentrations of Th17 cytokines IL-17A, IL-17F and IL-22, as well as Th2/immunoregulatory cytokine IL-10 were measured with ELISA assays.

RESULTS

Expression of IL-17A, IL-17F and IL-22 increased under stimulation, simultaneously with the increased IL-10 expression. Concentration of IL-17F tended to be lower in early neuroborreliosis than in late Lyme borreliosis and than in controls. B. afzelii elicited higher expression of IL-17A than the other two species.

CONCLUSIONS

IL-17A, IL-17F and IL-22 are synthesized simultaneously by PBMC stimulated with B. burgdorferi. There is no antagonism between Th17 response and IL-10 expression. The role of Th17 cytokines seems to differ depending on the clinical stage of Lyme borreliosis and on the B. burgdorferi species.