Tracing the cellular dynamics of sebaceous gland development in normal and perturbed states.

The sebaceous gland (SG) is an essential component of the skin, and SG dysfunction is debilitating1,2. Yet, the cellular bases for its origin, development and subsequent maintenance remain poorly understood. Here, we apply large-scale quantitative fate mapping to define the patterns of cell fate behaviour during SG development and maintenance. We show that the SG develops from a defined number of lineage-restricted progenitors that undergo a programme of independent and stochastic cell fate decisions. Following an expansion phase, equipotent progenitors transition into a phase of homeostatic turnover, which is correlated with changes in the mechanical properties of the stroma and spatial restrictions on gland size. Expression of the oncogene KrasG12D results in a release from these constraints and unbridled gland expansion. Quantitative clonal fate analysis reveals that, during this phase, the primary effect of the Kras oncogene is to drive a constant fate bias with little effect on cell division rates. These findings provide insight into the developmental programme of the SG, as well as the mechanisms that drive tumour progression and gland dysfunction.

Methods to improve adoptive T-cell therapy for melanoma: IFN-γ enhances anticancer responses of cell products for infusion.

Further development of adoptive T-cell therapy (ACT) with autologous tumor-infiltrating lymphocytes (TILs) has the potential to markedly change the long-term prognosis of patients with metastatic melanoma, and modifications of the original protocol that can improve its clinical efficacy are highly desirable. In this study, we demonstrated that a high in vitro tumor reactivity of infusion products was associated with clinical responses upon adoptive transfer. In addition, we systematically characterized the responses of a series of TIL products to relevant autologous short term-cultured melanoma cell lines from 12 patients. We provide evidence that antitumor reactivity of both CD8(+) and CD4(+) T cells could be enhanced in most TIL products by autologous melanoma sensitization by pretreatment with low-dose IFN-γ. IFN-γ selectively enhanced responses to tumor-associated antigens other than melanoma differentiation antigens. In addition, IFN-γ treatment was invariably associated with restored/increased cancer immunogenicity as demonstrated by upregulation of major histocompatibility complex molecules. These findings suggest a potential synergism between IFN-γ and ACT, and have important implications for clinical development of combination strategies for the treatment of metastatic melanoma.