Purpose: The pathologic interactions between tumor and host immune cells within the tumor microenvironment create an immunosuppressive network that promotes tumor growth and protects the tumor from immune attack. In this study, we examined the contribution of the immunomodulatory enzyme indoleamine 2,3-dioxygenase (IDO) on this phenomenon. Experimental Design: Expression of IDO was analyzed in colorectal cancer cell lines by reverse transcription-PCR and functional enzyme activity was assessed by high-pressure liquid chromatography. Semiquantitative immunohistochemistry was used to evaluate IDO expression in the tissue samples of 143 patients with colorectal carcinoma, and was then correlated with the number of tumor-infiltrating T cells and clinical variables. Results: In vitro IDO expression and functional enzyme activity in colorectal cancer cells was found to be strictly dependent on IFN-g stimulation. Immunohistochemical scores revealed IDOhigh expression in 56 of143 (39.2%) tumor specimens, whereas 87 of143 (60.8%) cases showed low IDO expression levels. IDO-high expression was associated with a significant reduction of CD3+ infiltratingT cells (46.02 F 7.25) as compared with tissue samples expressing low IDO (19.42 F 2.50; P = 0.0003). Furthermore, IDO-high immunoreactivity significantly correlated with the frequency of liver metastases (P = 0.003). Kaplan-Meier analysis showed the crossing of survival curves at 45 months. By multivariate Cox's analysis, IDO-high expression emerged as an independent prognostic variable (<45 months, P = 0.006; >45 months, P = 0.04).Conclusion: IDO-high expression by colorectal tumor cells enables certain cancer subsets to initially avoid immune attack and defeat the invasion of Tcells via local tryptophan depletion and the production of proapoptotic tryptophan catabolites. Thus, IDO significantly contributes to disease progression and overall survival in patients with colorectal cancer.Colorectal cancer is the most common gastrointestinal malignancy and one of the leading causes of cancer-related deaths worldwide (1). Five-year overall survival rates range from 90% for stage I to 75% and 50% for stage II and III

Baseline platelet production is dependent on thrombopoietin (TPO). TPO is constitutively produced and primarily regulated by receptor-mediated uptake by platelets. Inflammatory thrombocytosis is thought to be related to increased interleukin-6 (IL-6) levels. To address whether IL-6 might act through TPO to increase platelet counts, TPO was neutralized in vivo in C57BL/10 mice treated with IL-6, and hepatic TPO mRNA expression and TPO plasma levels were studied. Transcriptional regulation of TPO mRNA was studied in the hepatoblastoma cell line HepG2. Furthermore, TPO plasma levels were determined in IL-6-treated cancer patients. It is shown that IL-6-induced thrombocytosis in C57BL/10 mice is accompanied by enhanced hepatic TPO mRNA expression and elevated TPO plasma levels. Administration of IL-6 to cancer patients results in a corresponding increase in TPO plasma levels. IL-6 enhances TPO mRNA transcription in HepG2 cells. IL-6-induced thrombocytosis can be abrogated by neutralization of TPO, suggesting that IL-6 induces thrombocytosis through TPO. A novel pathway of TPO regulation by the inflammatory mediator IL-6 is proposed, indicating that the number of platelets by themselves might not be the sole determinant of circulating TPO levels and thus of thrombopoiesis. This regulatory pathway might be of relevance for the understanding of reactive thrombocytosis. IntroductionThrombocytosis can be classified into primary and secondary forms. Whereas primary thrombocytosis is observed in myeloproliferative syndromes, secondary or reactive thrombocytosis is noted in numerous clinical situations, 1 especially in association with inflammatory states of either infectious or noninfectious origin such as trauma and malignancy. 2,3 The extent to which mediators of the immune or hematopoietic system are involved in the regulation of the circulating platelet count in these conditions is insufficiently understood.Interleukin-6 (IL-6) plays a prominent role in inflammatory and neoplastic diseases. 4-6 Accordingly, mice deficient in IL-6 show a severely impaired acute-phase response. 7 Administration of IL-6 to humans has been associated with an increase in circulating platelet counts. [8][9][10][11][12][13][14] Furthermore, serum levels of IL-6 were significantly higher in patients with reactive thrombocytosis than in control patients. 15,16 Whether the thrombopoietic effect of IL-6 in vivo is caused by direct stimulation of hematopoietic progenitor cells or is indirectly mediated is unknown.Thrombopoietin (TPO), the ligand of the c-mpl proto-oncogene, is the primary regulator of proliferation and differentiation of megakaryocyte progenitors. [17][18][19][20][21][22][23] Mice rendered deficient in TPO or TPO receptor by gene targeting show severe thrombocytopenia, with platelet counts reduced by approximately 90%. 22,24 Treatment of mice, nonhuman primates, and humans with recombinant TPO or recombinant megakaryocyte growth and development factor, which constitutes a truncated, biologically active form of TPO, results in sig...

The ability to replace organs and tissues on demand could save or improve millions of lives each year globally and create public health benefits on par with curing cancer. Unmet needs for organ and tissue preservation place enormous logistical limitations on transplantation, regenerative medicine, drug discovery, and a variety of rapidly advancing areas spanning biomedicine. A growing coalition of researchers, clinicians, advocacy organizations, academic institutions, and other stakeholders has assembled to address the unmet need for preservation advances, outlining remaining challenges and identifying areas of underinvestment and untapped opportunities. Meanwhile, recent discoveries provide proofs of principle for breakthroughs in a family of research areas surrounding biopreservation. These developments indicate that a new paradigm, integrating multiple existing preservation approaches and new technologies that have flourished in the past 10 years, could transform preservation research. Capitalizing on these opportunities will require engagement across many research areas and stakeholder groups. A coordinated effort is needed to expedite preservation advances that can transform several areas of medicine and medical science.

Surgical site infections cause significant postoperative morbidity and increased healthcare costs. Bioadhesives used to fill surgical voids and support wound healing are typically devoid of antibacterial activity. Here, we report novel syringe-injectable bioadhesive hydrogels with inherent antibacterial properties prepared from mixing polydextran aldehyde (PDA) and branched polyethylenimine (PEI). These adhesives kill both Gram-negative and Gram–positive bacteria, while sparing human erythrocytes. An optimal composition of 2.5 wt % oxidized dextran and 6.9 wt % PEI sets within seconds forming a mechanically rigid (~1700 Pa) gel offering a maximum adhesive stress of ~ 2.8 kPa. A murine infection model showed that the adhesive is capable of killing S. pyogenes introduced subcutaneously at the bioadhesive’s surface, with minimal inflammatory response. The adhesive was also effective in a cecal ligation and puncture model, preventing sepsis and significantly improving survival. These bioadhesives represent novel, inherently antibacterial materials for wound filling applications.

Since the fi rst facial transplantation in 2005, 28 have been done worldwide with encouraging immunological, functional, psychological, and aesthetic outcomes. Unlike solid organ transplantation, which is potentially life-saving, facial transplantation is life-changing. This diff erence has generated ethical concerns about the exposure of otherwise young and healthy individuals to the sequelae of lifelong, high-dose, multidrug immunosuppression. Nevertheless, advances in immunomodulatory and immunosuppressive protocols, microsurgical techniques, and computer-aided surgical planning have enabled broader clinical application of this procedure to patients. Although episodes of acute skin rejection continue to pose a serious threat to face transplant recipients, all cases have been controlled with conventional immunosuppressive regimens, and no cases of chronic rejection have been reported.

NOS2-derived nitric oxide drives ferroportin-1–mediated iron export in Salmonella-infected macrophages, thus limiting bacterial growth.

Objective To minimize maintenance immunosuppression in upper-extremity transplantation to favor the risk-benefit balance of this procedure. Background Despite favorable outcomes, broad clinical application of reconstructive transplantation is limited by the risks and side effects of multidrug immunosuppression. We present our experience with upper-extremity transplantation under a novel, donor bone marrow (BM) cell-based treatment protocol (“Pittsburgh protocol”). Methods Between March 2009 and September 2010, 5 patients received a bilateral hand (n = 2), a bilateral hand/forearm (n = 1), or a unilateral (n = 2) hand transplant. Patients were treated with alemtuzumab and methylprednisolone for induction, followed by tacrolimus monotherapy. On day 14, patients received an infusion of donor BM cells isolated from 9 vertebral bodies. Comprehensive follow-up included functional evaluation, imaging, and immunomonitoring. Results All patients are maintained on tacrolimus monotherapy with trough levels ranging between 4 and 12 ng/mL. Skin rejections were infrequent and reversible. Patients demonstrated sustained improvements in motor function and sensory return correlating with time after transplantation and level of amputation. Side effects included transient increase in serum creatinine, hyperglycemia managed with oral hypoglycemics, minor wound infection, and hyperuricemia but no infections. Immunomonitoring revealed transient moderate levels of donor-specific antibodies, adequate immunocompetence, and no peripheral blood chimerism. Imaging demonstrated patent vessels with only mild luminal narrowing/occlusion in 1 case. Protocol skin biopsies showed absent or minimal perivascular cellular infiltrates. Conclusions Our data suggest that this BM cell-based treatment protocol is safe, is well tolerated, and allows upper-extremity transplantation using low-dose tacrolimus monotherapy.

Mitochondria play a critical role in myocardial cold ischemia-reperfusion (CIR) and induction of apoptosis. The nature and extent of mitochondrial defects and cytochrome c (Cyt c) release were determined by high-resolution respirometry in permeabilized myocardial fibers. CIR in a rat heart transplant model resulted in variable contractile performance, correlating with the decline of ADP-stimulated respiration. Respiration with succinate or N,N,N',N'-tetramethyl-p-phenylenediamine dihydrochloride (substrates for complexes II and IV) was partially restored by added Cyt c, indicating Cyt c release. In contrast, NADH-linked respiration (glutamate+malate) was not stimulated by Cyt c, owing to a specific defect of complex I. CIR but not cold ischemia alone resulted in the loss of NADH-linked respiratory capacity, uncoupling of oxidative phosphorylation and Cyt c release. Mitochondria depleted of Cyt c by controlled hypoosmotic shock provided a kinetic model of homogeneous Cyt c depletion. Comparison to Cyt c control of respiration in CIR-injured myocardial fibers indicated heterogeneity of Cyt c release. The complex I defect and uncoupling correlated with heterogeneous Cyt c release, the extent of which increased with loss of cardiac performance. These results demonstrate a complex pattern of multiple mitochondrial damage as determinants of CIR injury of the heart.