Celia M. Divino

Gr-1+CD115+ Immature Myeloid Suppressor Cells Mediate the Development of Tumor-Induced T Regulatory Cells and T-Cell Anergy in Tumor-Bearing Host

The accumulation of myeloid suppressor cells (MSCs) is associated with immune suppression in tumor-bearing mice and in cancer patients. The suppressive activity of MSC correlates with the expression of the myeloid markers Gr-1, CD115 (macrophage colony-stimulating factor receptor), and F4/80. Gr-1(+)CD115(+) MSCs, in addition to being able to suppress T-cell proliferation in vitro, can induce the development of Foxp3(+) T regulatory cells (Treg) in vivo, which are anergic and suppressive. Furthermore, the secretion of interleukin (IL)-10 and transforming growth factor-beta by Gr-1(+)CD115(+) MSCs was induced and enhanced, respectively, on IFN-gamma stimulation. The development of Treg requires antigen-associated activation of tumor-specific T cells, depends on the presence of IFN-gamma and IL-10, and is independent of the nitric oxide-mediated suppressive mechanism by MSC. Our data provide evidence that Gr-1(+)CD115(+) MSC can mediate the development of Treg in tumor-bearing mice and show a novel immune suppressive mechanism by which MSCs can suppress antitumor responses.

The Novel Role of Tyrosine Kinase Inhibitor in the Reversal of Immune Suppression and Modulation of Tumor Microenvironment for Immune-Based Cancer Therapies

In tumor-bearing hosts, myeloid-derived suppressor cells (MDSC) and T regulatory cells (Treg) play important roles in immune suppression, the reversal of which is vitally important for the success of immune therapy. We have shown that ckit ligand is required for MDSC accumulation and Treg development. We hypothesized that sunitinib malate, a receptor tyrosine kinase inhibitor, could reverse MDSC-mediated immune suppression and modulate the tumor microenvironment, thereby improving the efficacy of immune-based therapies. Treatment with sunitinib decreased the number of MDSC and Treg in advanced tumor-bearing animals. Furthermore, it not only reduced the suppressive function of MDSCs but also prevented tumor-specific T-cell anergy and Treg development. Interestingly, sunitinib treatment resulted in reduced expression of interleukin (IL)-10, transforming growth factor-beta, and Foxp3 but enhanced expression of Th1 cytokine IFN-gamma and increased CTL responses in isolated tumor-infiltrating leukocytes. A significantly higher percentage and infiltration of CD8 and CD4 cells was detected in tumors of sunitinib-treated mice when compared with control-treated mice. More importantly, the expression of negative costimulatory molecules CTLA4 and PD-1 in both CD4 and CD8 T cells, and PDL-1 expression on MDSC and plasmacytoid dendritic cells, was also significantly decreased by sunitinib treatment. Finally, sunitinib in combination with our immune therapy protocol (IL-12 and 4-1BB activation) significantly improves the long-term survival rate of large tumor-bearing mice. These data suggest that sunitinib can be used to reverse immune suppression and as a potentially useful adjunct for enhancing the efficacy of immune-based cancer therapy for advanced malignancies.

Immune Stimulatory Receptor CD40 Is Required for T-Cell Suppression and T Regulatory Cell Activation Mediated by Myeloid-Derived Suppressor Cells in Cancer

Immune tolerance to tumors is often associated with accumulation of myeloid-derived suppressor cells (MDSC) and an increase in the number of T-regulatory cells (Treg). In tumor-bearing mice, MDSCs can themselves facilitate the generation of tumor-specific Tregs. In this study, we demonstrate that expression of the immune stimulatory receptor CD40 on MDSCs is required to induce T-cell tolerance and Treg accumulation. In an immune reconstitution model, adoptive transfer of Gr-1+CD115+ monocytic MDSCs derived from CD40-deficient mice failed to recapitulate the ability of wild-type MDSCs to induce tolerance and Treg development in vivo. Agonistic anti-CD40 antibodies phenocopied the effect of CD40 deficiency and also improved the therapeutic efficacy of IL-12 and 4-1BB immunotherapy in the treatment of advanced tumors. Our findings suggest that CD40 is essential not only for MDSC-mediated immune suppression but also for tumor-specific Treg expansion. Blockade of CD40-CD40L interaction between MDSC and Treg may provide a new strategy to ablate tumoral immune suppression and thereby heighten responses to immunotherapy.

Effect of the number of lymph nodes sampled on postoperative survival of lymph node-negative esophageal cancer

The presence of lymph node (LN) metastases in esophageal cancer has important prognostic and treatment implications. However, the optimal number of LNs that should be examined for accurate staging is controversial. In the current study, the association between survival and the number of LNs evaluated was examined in patients who underwent resection of lymph node‐negative (American Joint Committee on Cancer [AJCC] TNM stage I‐IIA) esophageal cancer.

Risk Factors for Anastomotic Leak Following Colorectal Surgery: A Case-Control Study

OBJECTIVE To assess anastomotic leak (AL) risk factors in a large patient series. DESIGN Case-control study. SETTING The Mount Sinai Hospital. PATIENTS Ninety patients with AL following colorectal resection and 180 patients who underwent uncomplicated procedures. MAIN OUTCOME MEASURES Risk factors associated with development of AL. RESULTS The AL rate was 2.6%. Five risk factors for AL were identified: (1) preoperative albumin level lower than 3.5 g/dL (odds ratio [OR] 2.8; 95% confidence interval [CI], 1.3-5.1) (P = .03); (2) operative time of 200 minutes or longer (OR, 3.4; 95% CI, 2.0-5.8) (P = .01); (3) intraoperative blood loss of 200 mL or more (OR, 3.1; 95% CI, 1.9-5.3) (P = .01); (4) intraoperative transfusion requirement (OR, 2.3; 95% CI, 1.2-4.5) (P = .02); and (5) histologic specimen margin involvement in disease process in patients with inflammatory bowel disease (IBD) (OR, 2.9; 95% CI, 1.4-6.1) (P = .01). Patients with all 3 intraoperative risk factors had an OR of 22.1; 95% CI, 2.8-175.4 (P < .001) for development of AL. CONCLUSIONS Histologic resection margin involvement in disease process in patients with IBD, preoperative albumin levels lower than 3.5 g/dL, intraoperative blood loss of 200 mL or more, operative time of 200 minutes or more, and/or intraoperative transfusion requirement increased AL risk. Enteral nutritional optimization prior to elective surgery is essential. Proximal diversion should be considered for patients with all 3 intraoperative risk factors because they are at high risk for AL.

Predictors of mortality after colectomy for fulminant Clostridium difficile colitis

OBJECTIVES To present, to our knowledge, the largest experience with colectomy for fulminant Clostridium difficile colitis and to propose factors significant in predicting mortality. DESIGN Retrospective medical record review. SETTING University teaching hospital. PATIENTS Seventy-three patients undergoing colectomy between 1994 and 2005 for C difficile-associated pseudomembranous colitis. MAIN OUTCOME MEASURES Preoperative predictors of in-hospital mortality. RESULTS Seventy-three of 5718 cases (1.3%) of C difficile colitis required colectomy. Mean age was 68 years. In-hospital mortality was 34% (n = 25). Eighty-six percent (n = 63) of patients received a subtotal colectomy. Patients presented with diarrhea (84%; n = 61), abdominal pain (75%; n = 55), and ileus (16%; n = 12). Mean duration of symptoms was 7 days followed by 4 days of medical treatment prior to colectomy. On univariate analysis, an admitting diagnosis other than C difficile (P = .049), vasopressor requirement (P = .001), intubation (P = .001), and mental status changes (P < .001) were significant predictors of mortality. Arterial lactate level (4.9 vs 2.4 mmol/L; P = .007) was significantly higher and length of medical management (6.4 vs 3.0 days; P = .006) was significantly longer in the mortality group. Platelet counts (169 x 10(3)/microL vs 261 x 10(3)/microL [to convert to x 10(9)/L, multiply by 1]; P = .04) were significantly lower in the mortality group. On multivariate analysis, vasopressor requirement (P = .04; odds ratio, 5.0), mental status changes (P = .002; odds ratio, 12.6), and treatment length (P = .002; odds ratio, 1.4) remained significant predictors of mortality. CONCLUSIONS Colectomy for C difficile colitis carries a substantial mortality regardless of patient age and white blood cell count. Preoperative vasopressor requirement, mental status changes, and length of medical treatment significantly predict mortality.

Myeloid-Derived Suppressor Cells Prevent Type 1 Diabetes in Murine Models

Effective immunotherapy for type 1 diabetes (T1D) relies on active induction of peripheral tolerance. Myeloid-derived suppressor cells (MDSCs) play a critical role in suppressing immune responses in various pathologic settings via multiple mechanisms, including expansion of regulatory T cells (Tregs). In this study, we investigated whether MDSCs could act as APCs to induce expansion of Ag-specific Tregs, suppress T cell proliferation, and prevent autoimmune T1D development. We found that MDSC-mediated expansion of Tregs and T cell suppression required MHC-dependent Ag presentation. A murine T1D model was established in INS-HA/RAG−/− mice in which animals received CD4-HA-TCR transgenic T cells via adoptive transfer. We found a significant reduction in the incidence of diabetes in recipients receiving MDSC plus HA, but not OVA peptide, leading to 75% diabetes-free mice among the treated animals. To test further whether MDSCs could prevent diabetes onset in NOD mice, nondiabetic NOD/SCID mice were injected with inflammatory T cells from diabetic NOD mice. MDSCs significantly prevented diabetes onset, and 60% of MDSC-treated mice remained diabetes free. The pancreata of treated mice showed significantly lower levels of lymphocyte infiltration in islet and less insulitis compared with that of the control groups. The protective effects of MDSCs might be mediated by inducing anergy in autoreactive T cells and the development of CD4+CD25+Foxp3+ Tregs. Thist study demonstrates a remarkable capacity of transferred MDSCs to downregulate Ag-specific autoimmune responses and prevent diabetes onset, suggesting that MDSCs possess great potential as a novel cell-based tolerogenic therapy in the control of T1D and other autoimmune diseases.

Laparoscopic management of gastrointestinal stromal tumors

BackgroundSurgery remains the standard for nonmetastatic gastrointestinal stromal tumors (GISTs). Laparoscopic surgery should be considered for these tumors as their biologic behavior lends them to curative resection without requiring large margins or extensive lymphadenectomies.MethodsA retrospective review was performed of patients who underwent laparoscopic treatment of GISTs by surgeons at the Mount Sinai Medical Center from 2000-2005. Records were reviewed with respect to patient demographics, medical history, diagnostic workup, operative details, postoperative course, and pathologic characteristics.ResultsLaparoscopic surgery was attempted in 43 patients with GISTs. The average age was 65 years and 21 were women. Fifty-six percent of patients presented with anemia or gastrointestinal bleeding. The tumors were located in the stomach (65%) and in the small bowel (35%). The mean tumor sizes were 4.6 cm (stomach) and 3.7 cm (small bowel). Gastric operations included laparoscopic wedge (29%), sleeve (21%), and partial (29%) gastrectomies. The three gastric conversions were due to local invasion of tumor into adjacent organs or proximity to the gastroesophageal junction. Small bowel operations included laparoscopic resections with extracorporeal (47%) and intracorporeal anastamoses (33%). Conversion in small bowel operations was associated with coincidental pathology in addition to the GIST. This consisted of an associated bowel perforation and a synchronous colonic carcinoma. There was one mortality and a 9% morbidity rate, including an evisceration requiring reoperation. All tumors were pathologically confirmed with CD117 immunohistochemistry.ConclusionsIn light of their biologic behavior, GISTs should be considered for laparoscopic resection. This minimally invasive approach to these tumors can be performed safely and reliably.

Development and Function of Myeloid-Derived Suppressor Cells Generated From Mouse Embryonic and Hematopoietic Stem Cells

Emerging evidence suggests that myeloid‐derived suppressor cells (MDSCs) have great potential as a novel immune intervention modality in the fields of transplantation and autoimmune diseases. Thus far, efforts to develop MDSC‐based therapeutic strategies have been hampered by the lack of a reliable source of MDSCs. Here we show that functional MDSCs can be efficiently generated from mouse embryonic stem (ES) cells and bone marrow hematopoietic stem (HS) cells. In vitro‐derived MDSCs encompass two homogenous subpopulations: CD115+Ly‐6C+ and CD115+Ly‐6C− cells. The CD115+Ly‐6C+ subset is equivalent to the monocytic Gr‐1+CD115+F4/80+ MDSCs found in tumor‐bearing mice. In contrast, the CD115+Ly‐6C− cells, a previously unreported population of MDSCs, resemble the granulocyte/macrophage progenitors developmentally. In vitro, ES‐ and HS‐MDSCs exhibit robust suppression against T‐cell proliferation induced by polyclonal stimuli or alloantigens via multiple mechanisms involving nitric oxide synthase‐mediated NO production and interleukin (IL)‐10. Impressively, they display even stronger suppressive activity and significantly enhance ability to induce CD4+CD25+Foxp3+ regulatory T‐cell development compared with tumor‐derived MDSCs. Furthermore, adoptive transfer of ES‐MDSCs can effectively prevent alloreactive T‐cell‐mediated lethal graft‐versus‐host disease, leading to nearly 82% long‐term survival among treated mice. The successful in vitro generation of MDSCs may represent a critical step toward potential clinical application of MDSCs. STEM CELLS 2010;28:620–632

Anal fissure : 20-year experience

PURPOSE: This study was designed to review a 20-year experience of the treatment of patients with anal fissure to identify possible etiologic factors and to explore effective preventative measures and the ideal treatment for this disease. METHODS: From January 1972 to December 1991, 1,391 patients (700 males, 691 females; average age, 39 years) with chronic symptomatic anal fissures underwent surgical treatment using either open or closed techniques. The following procedures were performed: 1) internal sphincterotomy for 1,313 idiopathic fissures; 2) C-anoplasty for 36 cases of anal stricture; 3) debridement and sphincterotomy for 25 patients with postsurgical nonhealing wounds; 4) bilateral excision of the protruding internal sphincter for 17 patients with “subluxation.” Acute superficial anal fissures were treated conservatively, with emphasis on anal hygiene. RESULTS: Acute superficial anal fissures responded well to conservative management. Over 95 percent of patients with chronic anal fissures treated by surgery had satisfactory relief of symptoms. Early complications included urinary retention (1.4 percent), bleeding (1.1 percent), and abscess and fistula formation (0.7 percent). Late complications manifested as flatus and liquid incontinence (1.5 percent), delayed wound healing (1.4 percent), recurrence of fissures (1.3 percent), and symptomatic itching and burning (1.1 percent). The complication rate was higher in the group that underwent closed sphincterotomy than in the group treated by open techniques. CONCLUSIONS: Proper anal hygiene is important in both prevention and initial conservative management of symptomatic anal fissures. For chronic intractable cases, open lateral internal sphincterotomy is strongly recommended. C-anoplasty should be done when strictures are present. Excision of the protruding internal sphincter is recommended in patients who present with an excessively elongated, tight anal canal with a partially protruding internal sphincter.