IL-33-ILC2 axis promotes anti-tumor CD8+ T cell responses via OX40 signaling.

Group 2 innate lymphoid cells (ILC2s) are resident cells and participate in innate and adaptive immunity. In the tumor microenvironment (TME), ILC2s contribute to both tumorigenesis and inhibition of tumor growth, but the true role of ILC2s in TME construction remains unclear. We show that IL-33 treatment induces an anti-tumor effect in vivo in a mouse model of melanoma in which ILC2s and CD8+ T cells infiltrate into tumor tissue. This anti-tumor effect is dependent on CD8+ T cells, however, IL-33 does not act directly on CD8+ T cells because the cells lack ST2, the receptor for IL-33. ILC2s and CD8+ T cells in tumors of IL-33-treated mice express OX40 ligand (OX40L) and OX40, respectively, and in vivo blockade of OX40L-OX40 interaction canceled the anti-tumor effect of IL-33. Co-culture of CD8+ T cells expressing OX40 with IL-33-stimulated ILC2 expressing OX40L promoted cell activation and proliferation of CD8+ T cells, which was significantly suppressed by administration of anti-OX40L blocking antibody. Thus, the IL-33-ILC2 axis promotes CD8+ T cell responses via OX40/OX40L interaction and exerts an anti-tumor effect.

[Clinical Significance of the Curative Effect after Neoadjuvant Chemotherapy for Triple-Negative Breast Cancer-Correlation to Prognosis].

We investigated factors related to the recurrence and prognosis of patients with triple-negative breast cancer (TNBC)after neoadjuvant chemotherapy(NAC). Of the 545 patients who underwent surgery after NAC between January 2013 and December 2016, 131 patients had TNBC. An analysis of each TNBC case indicated that the presence or absence of clinical lymph node metastasis(cN)before treatment might be a predictive factor of prognosis. There were 57(43.5%)pathological complete response(pCR)(ypT0 or ypTis/N0)cases after NAC. Overall survival(OS)and disease free survival(DFS) were significantly better in pCR cases than in non-pCR cases. However, recurrence was observed in 8 of 57(14%)pCR cases and 29 of 74(39%)non-pCR cases. The factors defining DFS from the univariate analysis of the non-pCR group were cN, ypT, ypN, and vascular invasion. The multivariate analysis of these factors suggested that residual cN and vascular invasion might be independent factors predicting DFS. Residual vascular invasion was found to predict OS, and was considered to be a poor prognostic factor.