Showing papers by "Pentao Liu published in 2010"

Reprogramming of T Cells to Natural Killer–Like Cells upon Bcl11b Deletion

Abstract: T cells develop in the thymus and are critical for adaptive immunity. Natural killer (NK) lymphocytes constitute an essential component of the innate immune system in tumor surveillance, reproduction, and defense against microbes and viruses. Here, we show that the transcription factor Bcl11b was expressed in all T cell compartments and was indispensable for T lineage development. When Bcl11b was deleted, T cells from all developmental stages acquired NK cell properties and concomitantly lost or decreased T cell-associated gene expression. These induced T-to-natural killer (ITNK) cells, which were morphologically and genetically similar to conventional NK cells, killed tumor cells in vitro, and effectively prevented tumor metastasis in vivo. Therefore, ITNKs may represent a new cell source for cell-based therapies.

PiggyBac Transposon Mutagenesis: A Tool for Cancer Gene Discovery in Mice

Abstract: Transposons are mobile DNA segments that can disrupt gene function by inserting in or near genes. Here, we show that insertional mutagenesis by the PiggyBac transposon can be used for cancer gene discovery in mice. PiggyBac transposition in genetically engineered transposon-transposase mice induced cancers whose type (hematopoietic versus solid) and latency were dependent on the regulatory elements introduced into transposons. Analysis of 63 hematopoietic tumors revealed that PiggyBac is capable of genome-wide mutagenesis. The PiggyBac screen uncovered many cancer genes not identified in previous retroviral or Sleeping Beauty transposon screens, including Spic, which encodes a PU.1-related transcription factor, and Hdac7, a histone deacetylase gene. PiggyBac and Sleeping Beauty have different integration preferences. To maximize the utility of the tool, we engineered 21 mouse lines to be compatible with both transposon systems in constitutive, tissue- or temporal-specific mutagenesis. Mice with different transposon types, copy numbers, and chromosomal locations support wide applicability.

Critical roles of Bcl11b in T-cell development and maintenance of T-cell identity.

Abstract: T-cell development primarily occurs in the thymus and involves in the interactions of many important transcription factors. Until recently, no single transcription factor has been identified to be essential for T-cell lineage commitment or maintenance of T-cell identity. Recent studies have now identified the zinc finger transcription factor Bcl11b to be essential for T-cell development and for maintenance of T-cell identity. Remarkably, T cells acquire NK cell properties upon Bcl11b deletion. These reprogrammed cells have unique properties in proliferation, cytokine dependency and killing target cells, and may therefore provide a new cell source for some cell-based therapies.

Antigen-specific clonal expansion and cytolytic effector function of CD8+ T lymphocytes depend on the transcription factor Bcl11b

Abstract: CD8+ T lymphocytes mediate the immune response to viruses, intracellular bacteria, protozoan parasites, and tumors. We provide evidence that the transcription factor Bcl11b/Ctip2 controls hallmark features of CD8+ T cell immunity, specifically antigen (Ag)-dependent clonal expansion and cytolytic activity. The reduced clonal expansion in the absence of Bcl11b was caused by altered proliferation during the expansion phase, with survival remaining unaffected. Two genes with critical roles in TCR signaling were deregulated in Bcl11b-deficient CD8+ T cells, CD8 coreceptor and Plcγ1, both of which may contribute to the impaired responsiveness. Bcl11b was found to bind the E8I, E8IV, and E8V, but not E8II or E8III, enhancers. Thus, Bcl11b is one of the transcription factors implicated in the maintenance of optimal CD8 coreceptor expression in peripheral CD8+ T cells through association with specific enhancers. Short-lived Klrg1hiCD127lo effector CD8+ T cells were formed during the course of infection in the absence of Bcl11b, albeit in smaller numbers, and their Ag-specific cytolytic activity on a per-cell basis was altered, which was associated with reduced granzyme B and perforin.

Cells, compositions and methods

Abstract: Method of producing induced T-to-Natural-Killer [ITNK] cells, target T cells and/or target pro-T cells from T cells and/or pro-T cellswhich method involvesmodulating the activity and/or effect of at least one Bcl11b gene and/or protein present in a T cell and/or pro-T cell, and converting said T cell and/or pro-T cell to an ITNK cell or target Tcells and/or target pro-T cells is described. ITNK cells, target T cells and/or target pro-T cells produced by such method and mature activated T cells in which Bcl11b expression is downregulated or absent,and the use of such cells or modulators of Bcl11b in medicine is also described.