Pneumologie 2016; 70 - P17
DOI: 10.1055/s-0036-1584620

The influence of the probiotic compound D-Tryptophan on the differentiation of murine naïve CD4+ spleen cells

G Jatzlauk 1, S Bartel 1, S Reuter 1, S Krauss-Etschmann 1
  • 1Division of Experimental Asthma Research, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Borstel, Germany

Introduction: Current therapies for asthma improve symptoms but cannot cure the disease or its prevalence prompting demands for alternatives. The use of probiotic bacteria to prevent chronic diseases could represent a cost-effective approach. However, clinical studies have shown contradictory findings, possibly explained by the individual and highly complex interaction between probiotics and host. To reduce this complexity, our group investigates the use of isolated probiotic compounds, instead of living bacteria. Recently we identified D-Tryptophan (D-Trp) showing immune modulatory properties. As a next step we plan to investigate D-Trp's influence on particular immune cells.

Methods: In a first approach we analyzed the effect of D-Trp on T-cell differentiation using murine, naïve spleen CD4+ T-cells which were differentiated in vitro (IL-2, anti-CD3/CD28) into Th1 (IL-12, anti-IL-4), Th2 (IL-4, anti-IFNγ) and iTreg (TGF-β) in the presence or absence of (A) 10 or (B) 50µM D-Trp. Differentiation was assessed on cytokine and mRNA levels by qRT-PCR, flow cytometry and cytometric bead array. Results were obtained from three independent experiments and evaluated using mean fold change (FC) to untreated control (no D-Trp).

Results: In the presence of D-Trp naive Th0-cells showed a decreased differentiation into Th2-cells, as indicated by down-regulated mRNA levels of IL-4 (FC A: 0.85, B: 0.75) and IL-5 (FC A: 0.82, B: 0.89) and by lowered cytokine production of IL-5 (FC A: 0.97, B: 0.78) and IL-13 (FC A: 0.92, B: 0.75). D-Trp treatment also resulted in slightly increased differentiation towards Treg. In these cells IL-10 mRNA levels were elevated (FC A: 1.01, B: 1.17). A consistent effect of D-Trp on Th1 development was not observed.

Discussion: Our results indicate that D-Trp affects T-cell differentiation by suppressing Th2 and promoting Treg differentiation. Prospectively, we aim to confirm this effect in a more physiological co-culture system with dendritic cells.