Immunotherapy with TCR-redirected T cells: comparison of TCR-transduced and TCR-engineered hematopoietic stem cell-derived T cells.

Redirecting Ag specificity by transfer of TCR genes into PBLs is an attractive method to generate large numbers of cytotoxic T cells for immunotherapy of cancer and viral diseases. However, transferred TCR chains can pair with endogenous TCR chains, resulting in the formation of mispaired TCR dimers and decreased or unspecific reactivity. TCR gene transfer into hematopoietic stem cells (HSCs) is an alternative to create T cells with desired Ag specificity, because in this case expression of endogenous TCR chains is then less likely owing to allelic exclusion. We generated TCR-transduced T cells from peripheral T cells using the lymphocytic choriomeningitis virus-specific P14 TCR. After transfer of the P14 TCR genes into HSCs and subsequent reconstitution of irradiated mice, TCR-engineered HSC-derived T cells were produced. We then compared the Ag-specific T cell populations with P14 TCR-transgenic T cells for their therapeutic efficiency in three in vivo models. In this study, we demonstrate that TCR-transduced T cells and TCR-engineered HSC-derived T cells are comparable in controlling lymphocytic choriomeningitis virus infection in mice and suppress growth of B16 tumor cells expressing the cognate Ag in a comparable manner.

Arginase II Promotes Macrophage Inflammatory Responses Through Mitochondrial Reactive Oxygen Species, Contributing to Insulin Resistance and Atherogenesis.

BACKGROUND: Macrophage-mediated chronic inflammation is mechanistically linked to insulin resistance and atherosclerosis. Although arginase I is considered antiinflammatory, the role of arginase II (Arg-II) in macrophage function remains elusive. This study characterizes the role of Arg-II in macrophage inflammatory responses and its impact on obesity-linked type II diabetes mellitus and atherosclerosis. METHODS AND RESULTS: In human monocytes, silencing Arg-II decreases the monocytes' adhesion to endothelial cells and their production of proinflammatory mediators stimulated by oxidized low-density lipoprotein or lipopolysaccharides, as evaluated by real-time quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. Macrophages differentiated from bone marrow cells of Arg-II-deficient (Arg-II(-/-)) mice express lower levels of lipopolysaccharide-induced proinflammatory mediators than do macrophages of wild-type mice. Importantly, reintroducing Arg-II cDNA into Arg-II(-/-) macrophages restores the inflammatory responses, with concomitant enhancement of mitochondrial reactive oxygen species. Scavenging of reactive oxygen species by N-acetylcysteine prevents the Arg-II-mediated inflammatory responses. Moreover, high-fat diet-induced infiltration of macrophages in various organs and expression of proinflammatory cytokines in adipose tissue are blunted in Arg-II(-/-) mice. Accordingly, Arg-II(-/-) mice reveal lower fasting blood glucose and improved glucose tolerance and insulin sensitivity. Furthermore, apolipoprotein E (ApoE)-deficient mice with Arg-II deficiency (ApoE(-/-)Arg-II(-/-)) display reduced lesion size with characteristics of stable plaques, such as decreased macrophage inflammation and necrotic core. In vivo adoptive transfer experiments reveal that fewer donor ApoE(-/-)Arg-II(-/-) than ApoE(-/-)Arg-II(+/+) monocytes infiltrate into the plaque of ApoE(-/-)Arg-II(+/+) mice. Conversely, recipient ApoE(-/-)Arg-II(-/-) mice accumulate fewer donor monocytes than do recipient ApoE(-/-)Arg-II(+/+) animals. CONCLUSIONS: Arg-II promotes macrophage proinflammatory responses through mitochondrial reactive oxygen species, contributing to insulin resistance and atherogenesis. Targeting Arg-II represents a potential therapeutic strategy in type II diabetes mellitus and atherosclerosis. (J Am Heart Assoc. 2012;1:e000992 doi: 10.1161/JAHA.112.000992.).

Period2 gene mutant mice show compromised insulin-mediated endothelial nitric oxide release and altered glucose homeostasis.

Period2 (Per2) is an important component of the circadian clock. Mutation of this gene is associated with vascular endothelial dysfunction and altered glucose metabolism. The aim of this study is to further characterize whole body glucose homeostasis and endothelial nitric oxide (NO) production in response to insulin in the mPer2(Brdm1) mice. We show that mPer2(Brdm1) mice exhibit compromised insulin receptor activation and Akt signaling in various tissues including liver, fat, heart, and aortas with a tissue-specific heterogeneous diurnal pattern, and decreased insulin-stimulated NO release in the aortas in both active and inactive phases of the animals. As compared to wild type (WT) mice, the mPer2(Brdm1) mice reveal hyperinsulinemia, hypoglycemia with lower fasting hepatic glycogen content and glycogen synthase level, no difference in glucose tolerance and insulin tolerance. The mPer2(Brdm1) mice do not show increased predisposition to obesity either on normal chow or high fat diet compared to WT controls. Thus, mice with Per2 gene mutation show altered glucose homeostasis and compromised insulin-stimulated NO release, independently of obesity.