Both types of highly concentrated platelet components were effective in achieving high closure rates of macular holes. These autologous platelet components possess the quality standard of blood bank components and could be of great benefit for initiating wound healing in other clinical settings.

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Brandt K, van der Bosch J, Fliegert R, Gehring S. TSST-1 Induces Th1 or Th2 Differentiation in NaõÈ ve CD4 T Cells in a Dose-and APC-Dependent Manner. Scand J Immunol 2002;56:572±579 Superantigens are potent activators of the immune system, causing a variety of diseases, ranging from food poisoning to septic shock. Here, we examined the effects of different toxic shock syndrome toxin 1 (TSST-1) concentrations on the activation, proliferation and synthesis of interferon-g (IFN-g) and interleukin-4 (IL-4) in purified naõÈ ve human CD4 T cells in a serum-free in vitro system. TSST-1 given in low doses (1±10 pg/ml) generates a pronounced T helper 2 (Th2)-like cytokine profile, characterized by elevated IL-4-expressing T-cell populations and reduced IFN-g-producing populations, whereas higher doses (100 pg/ml) induce a Th1-like profile, with increased expression of IFN-g and reduced expression of IL-4. These patterns were even more pronounced by adding exogenous cytokines like IL-12 and IL-4 and by the type of antigen-presenting cells (APCs). Thus, B cells induced Th2 shifts, whereas monocytes favoured Th1 induction. Moreover, IL-12 in conditions with B cells counteracted their Th2 bias. Interestingly, in purified naõÈ ve T-cell cultures, containing a small population of HLA-DR T cells, Th1/Th2 differentiation can be induced by TSST-1 too. There, Th-cell polarization is strongly dependent on TSST-1 concentration, indicating that this is a key parameter in regulating the differentiation of T cells. In conclusion, our data show that Th1/Th2 differentiation of TSST-1-stimulated naõÈ ve T cells is controlled by the type of APCs, and in APC-depleted cultures, it depends on the presence of HLA-DR cells and TSST-1 concentration.

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