Effect of priming on the immunomodulatory response of mesenchymal stem cells (adMSC) with immunogenic synthetic peptides from Leishmania braziliensis.

Resum

Leishmaniasis is a zoonotic disease that causes major public health problems, mainly in tropical or subtropical countries,causing approximately 70,000 deaths per year and currently there is no approved vaccine. Therefore, research into thedevelopment of effective therapies that help both the elimination of the parasite and the aesthetic recovery of wounds, throughthe search for synthetic antigenic systems with immunogenic activity, is nowadays a necessity. Recently, theimmunotherapeutic potential of human mesenchymal stem cells (hMSCs) and the secretome and exocytic vesicles theyproduce when cultured in specific media have been described [1]. It has also been described that they have regenerative andantimicrobial potential and that these effects are enhanced when stimulated with different antigens. The present study aimedto characterize the secretome of hMSCs, treated with synthetic immunogenic peptides from Leishmania braziliensis, and toevaluate their immunomodulatory potential. Adipose tissue-derived hMSCs, which were characterized according tointernational standards [2], were used. For this work, cells at passage eight were exposed to two synthetic immunogenicpeptides MSD1 and CBP, designed in silico, from L. braziliensis and lipopolysaccharide (LPS) as a positive control. Thesecretome was collected at 48 and 96h and characterized firstly by measuring the expression of Interleukin 6 (IL-6) by anELISA method and the expression of cytokines and other proteins using an 80- antibodies targets in a chemiluminescencepanel. The results have shown a proinflammatory profile at the level of cytokine expression for the treatments with MSD1, CPBand LPS [3,4]. These were characterized by an increase in the expression of proinflammatory cytokines such as INF-γ, IL-6,IL-16, TNF-α and TNF-β. In summary, the secretome of adipose tissue hMSC pre-treated with synthetic immunogenicpeptides from L. braziliensis presents differences in the level of cytokine expression with a tendency towards aproinflammatory profile.