Primary Tuberculosis of Cervix Which Simulated Endocervical Polyp: A Case Study

Tuberculosis has been described as the second great "Imitator" as it can imitate various other disease processes. The manifestations of genitourinary tuberculosis are protean in nature; still tuberculosis is a health concern in South-East Asia region. Tuberculosis of the cervix is rarely found and accounts for 5-10% among all types of genital tuberculosis. Despite meticulous history and clinical examination does not always lead to suspect this disease, the definitive diagnosis is based on the demonstration of the characteristic lesion on histopathology or on bacterial isolation. We are reporting a case of a 26-years-old woman who presented with secondary amenorrhea and a benign looking endocervical polyp. Diagnosis of cervical tuberculosis could be clinched after tissue biopsy which revealed caseous granuloma on histopathological examination along with other supportive laboratory investigation reports. Patient was subsequently started on antitubercular therapy (ATT) according to directly observed treatment schedule- category I, resulting in resumption of her menses after four months of starting of ATT. An awareness of the atypical clinical manifestations of tuberculosis is important, especially in regions where tuberculosis continues to be a major public health problem, such as Bangladesh. One should have high index of suspicion in order to diagnose tuberculosis of cervix in such cases, especially in high prevalence areas, so that patients can be managed appropriately with antitubercular therapy and complications can be prevented.

Abstract 1709: Targeting immune checkpoint therapy to the lung tumor microenvironment

Lung cancer is the leading cause of cancer deaths worldwide. Many lung cancer patients are diagnosed with advanced disease. These patients have a low 5-year survival rate and limited treatment options. Novel therapies, which target biomarkers that are overexpressed in lung cancer but have basal expression in benign tissue, are desperately needed. The goal of this work was to develop a targeted agent for immune checkpoint therapy of lung cancer. Recently, immune checkpoint inhibitors have been approved for use in lung cancer and many more are being tested in clinical trials. The current immune checkpoint inhibitor agents are not tumor-targeted. Targeting the immune checkpoint inhibitor to tumor cell-surface markers should concentrate the conjugate in the tumor microenvironment and enhance the immune response in the tumor while reducing the systemic dosages needed, resulting in lower systemic toxicity.

The delta opioid receptor (DOR) is expressed in some lung cancers, but is not expressed or is expressed only at basal levels in normal tissues outside the brain. We have previously synthesized fluorescently-labeled DOR-targeted imaging agents based on a synthetic peptide antagonist (DORL). These targeted fluorescent agents have high affinity and selectivity for DOR, and exhibit good pharmacokinetic (PK) and biodistribution (BD) profiles, i.e. specific tumor uptake with rapid systemic clearance and no uptake in tissues of concern, e.g. brain. We are now developing lung cancer-specific immunotherapy agents that target the DOR by conjugating DORL to immunomodulatory molecules. In the current work, we synthesized a fluorescently-labeled DOR targeting ligand and conjugated it to an anti-PD1 antibody (DORL-PD1). We synthesized immunoconjugates with several targeting ligand-to-antibody ratios (TARs). We engineered murine lung cancer cells to constitutively express the DOR. By lanthanide time-resolved fluorescence (LTRF) competitive binding assays, we have shown that the agents have high avidity for the DOR in vitro with higher TARs resulting in higher binding avidity. We characterized the uptake of DORL-PD1 in vitro using live-cell fluorescence microscopy. Using syngeneic engraftment tumor models in immunocompetent mice, we performed longitudinal fluorescence imaging studies to determine the agent circulation time (PK), tumor selectivity and tissue distribution (BD). Immune checkpoint efficacy studies were performed using the DOR negative mouse tumor models.

In conclusion, we have synthesized fluorescent DOR-targeted immune checkpoint therapy agents, DORL-PD1; demonstrated avidity and selectivity for the DOR in vitro and in vivo; and immune checkpoint therapy efficacy in vivo. Future studies will evaluate the efficacy of DORL-PD1 in immune competent mice bearing DOR positive tumors. These agents could be useful for increasing the efficacy and reducing systemic toxicity of immune-checkpoint therapy of lung cancer.

Citation Format: Allison S. Cohen, Michael L. Doligalski, Hong Zheng, Narges K. Tafreshi, Veronica Estrella, Nella Delva, Jonathan Nguyen, Amer Beg, Mark L. McLaughlin, David L. Morse. Targeting immune checkpoint therapy to the lung tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1709. doi:10.1158/1538-7445.AM2017-1709

Abstract 5662: MEK inhibitors potentiate tumor immune surveillance by enhancing cancer cell response of IFNγ

FDA approved mitogen-activated protein kinase (MAPK) kinase (MEK) targeting inhibitors such as trametinib have recently been reported to enhance anti-tumor immunity in multiple preclinical models. It is hypothesized that the combination of such MEK inhibitors with immune checkpoint blockade will have synergistic effects and cause further tumor regression. Immune checkpoint inhibitors such as anti-PD-1 overcome immunosuppressive signaling in the activated T cells, yielding higher levels of Interferon-gamma (IFNγ) release. IFNγ plays a key role in a wide range of immune responses by direct activation of JAK-STAT1 pathway through the binding of IFNγ receptor. JAK-STAT1 regulates transcription of downstream effector genes that are involved in tumor immune surveillance. Many studies have shown that in cancer cells, transcription of T cell chemokines CXCL9,10,11, as well as PD-L1 and MHC-I are induced upon stimulation with IFNγ. While there are some recent studies indicating MEK inhibitors enhance T cell activity and function, here we report for the first time that targeted inhibition of MEK increases tumor cells response to IFNγ and results in significant upregulation of target genes including T cell chemokines, MHC-I, as well as PD-L1.

We treated a panel of 20 human lung cancer cell lines with MEK inhibitor U0126 followed by IFNγ stimulation, and showed that the expression of CXCL10 is significantly increased as compared to IFNγ stimulation alone. Furthermore, we found that instead of MEK inhibition, knock down of KRAS in the KRAS mutant cell lines such as A549 and H2122 results in more dramatic CXCL10 upregulation upon IFNγ stimulation. This indicates the potential of increasing tumor T cell infiltration upon MEK targeted therapy. Next, to elucidate the underlying molecular mechanism, we analyzed JAK-STAT1 pathway in mouse lung cancer cell lines LKR, 344, and colon cancer cell line CT26, in which trametinib mediated synergistic expression of CXCL9,10, 11 and MHC-I, PD-L1 were observed. The phosphorylation as well as total protein of JAK2, STAT1 are increased in cells that are pre-treated with trametinib, as compared to IFNγ stimulation alone. Treatment of JAK inhibitor Ruxolitinib as well as knockout of IFNγR1 in LKR cells completely abolishes CXCL10 expression. Importantly, trametinib enhanced response to PD-1 blockade in the lung tumor models. In conclusion, our study demonstrates that targeting MEK signaling in cancer cells increases the response of IFNγ through JAK-STAT1 pathway, which may potentially enhance immune surveillance and response to immune checkpoint blockade.

Citation Format: Mengyu Xie, Hong Zheng, Amer Beg. MEK inhibitors potentiate tumor immune surveillance by enhancing cancer cell response of IFNγ [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5662. doi:10.1158/1538-7445.AM2017-5662

Correlation between Umbilical Cord Diameter and Cross Sectional Area with Gestational Age and Foetal Anthropometric Parameters

The objective of the study was to find out correlation between umbilical cord diameter, cross sectional area with gestational age and foetal anthropometric parameters. This cross sectional study was conducted among healthy women between the 24(th) and 40(th) completed weeks of a normal pregnancy in the Department of Radiology & Imaging, Mymensingh Medical College Hospital, Mymensingh during the study period, from July 2009 to June 2011. A total of 230 consecutive normal pregnancy patients were included in the study. The diameter & cross-sectional area of the umbilical cord were measured on a plane adjacent to the junction of the umbilical cord and the fetal abdomen, in cross-section, with maximum magnification of the image. The cord was manually circled, and it's cross sectional areas was automatically calculated by the ultrasonograph. The mean±SD age was 24.3±4.7 years with range from 19 to 36 years. The mean gestational age was 32.1±4.5 weeks and more than a half (56.4%) of the pregnant women were nulliparas. A positive significant (p<0.001) correlation were found between umbilical cord diameter with bi-parietal diameter (r=0.548); head circumference (r=0.411); abdominal circumference (r=0.444); femur length (r=0.366) and gestational age gestation age (r=0.643). Similarly, a significant (p<0.001) positive week correlation were found between umbilical cross sectional area with bi-parietal diameter (r=0.3303); head circumference (r=0.3202); abdominal circumference (r=0.2651); femur length (r=0.3307) and gestation age (r=0.4051). A positive significant better correlation was found with umbilical cord diameter than cross sectional area with foetal anthropometric parameters.

Obstetric Outcome in Early and Late Onset Gestational Diabetes Mellitus

Obstetric outcome in early onset and late onset GDM was compared in a prospective study conducted at the Department of Obstetrics & Gynecology in BIRDEM, Dhaka, Bangladesh. A total 120 pregnant women were recruited purposively for the study in which 60 were early onset GDM and 60 were late onset GDM during study period of January 2008 to December 2009. Patients were followed up in different periods of gestation, during delivery and early postpartum period & findings were compared between two groups. BMI & family history of diabetes were significantly higher in early GDM group (p<0.05). Evidence of increased glycaemia was observed in early GDM group & difference of glycaemic status was statistically significant (p<0.05). Insulin was needed in 85% of early onset GDM and 55% in late onset GDM. There was also significant difference (p<0.05). In this study, 23.3% of early onset GDM group developed pre-eclampsia while in late onset GDM it was 10% and was statistically significant (p<0.05). Regarding intrapartum & postpartum complications - perineal tear, PPH wound infection, puerperal sepsis were more in early onset than late onset GDM group with no significant difference. Regarding foetal outcome, 8.3% early GDM group delivered asphyxiated baby in comparison to 3.3% in late GDM group. Twenty percent (20%) of early onset GDM group had to admit their babies in neonatal unit while in late onset group it was 5%. There was significant difference between two groups (p<0.05). Neonatal hypoglycaemia was also statistically significantly (p<0.05) higher in early GDM group. Neonatal hyper-bilirubinaemia, RDS, perinatal death was more in early onset GDM subjects. Early onset GDM subjects are high risk subgroup & have significant deleterious effect on maternal and perinatal outcome than late GDM groups.

Cereblon, a molecular target of lenalidomide (IMiDs), negatively regulates T cell activation (IRM7P.715)

Thalidomide analogs classified as immunomodulatory drugs (IMiDs) are rapidly emerging T-cell stimulants for the treatment of cancer. Cereblon, an E3-Ub ligase receptor with no known immune regulatory function, is the first identified target of IMiDs. The drug is hypothesized to have antagonistic properties by interfering with substrate recruitment to the thalidomide-binding domain in cereblon, and agonistic activity through an exposed ring that may recruit new proteins to the Ub complex. To explore this further at the molecular level, we studied immune regulation in cereblon deficient mice (crbn-/-), which exhibited an expanded white blood cell and neutrophil compartment, and higher numbers of peripheral and splenic lymphocytes. Mature crbn-/- T cells were capable of proliferation and IL-2 production following CD3 ligation in the absence of CD28 co-ligation. This positively associates with proximal phosphorylation events including pZap70, pAKT, pro-survival Bcl-XL and Bcl-2 protein expression, and corresponds with decreased pro-apoptotic proteins Bim, Bad, and Bax. Consistent with this data in a lethal graft-versus-host (GVHD) model, MHC-class I mismatched T cells from crbn-/- mice showed shortened post-transplant survival, greater weight-loss, and higher IFN-γ compared to transplanted wild-type T-cells. These data suggest that native targets of cereblon restrain the activation threshold of T-cells and that IMiD-associated blockade of cereblon leads to T-cell potentiation.

Defining a novel role for the NF-κB pathway in proximal TCR signaling. (IRM10P.746)

In the accepted model of T cell activation, parallel and independent signal transduction pathways activate the transcription factors NF-κB, NFAT and AP-1 to drive clonal expansion of T cells in response to antigen. Surprisingly, we found that CD8 T cells lacking NF-κB subunits p50 and cRel fail to activate NFAT contributing to their severely impaired in vivo responsiveness. We further demonstrated that attenuated NFAT activation was due to diminished Calcium influx upon TCR engagement, and that this reduction was accomplished via sub-par phosphorylation of PLCγ. The functional relevance of impaired PLCγ activation was demonstrated by rescue of p50-/-cRel-/- T cell proliferation through pharmacological initiation of PKC and Calcium pathways. While no deficiencies in expression of TCR complex proteins were seen, we did note defects in early TCR-induced Lck and Zap70 activation, and reduced expression of IKKβ and IKKγ in p50-/-cRel-/- T cells. Beyond established roles in NF-κB activation, we show that IKKβ /γ are also crucial for TCR-induced Lck, Zap70 and PLCγ activation. These findings define a novel pathway of “retrograde signaling” in T cells whereby NF-κB subunits modulate expression of proteins which are crucial for early TCR-induced signaling. Therefore, robust T cell activation occurs in cells exhibiting baseline activation of the pro-survival NF-κB pathway either through TCR tickling or non-TCR pathways.

The Th17 immune response is controlled by a c-Rel−RORγ−RORγT transcriptional axis (50.36)

The Th17 cells utilize the retinoid-related orphan receptor-γ (Rorg) gene to specify their differentiation and lineage-specific function. However, how Rorg is switched on during Th17 differentiation is unknown. We report here that the transcription factor c-Rel drives Th17 differentiation by binding to, and activating, two distinct Rorg promoters that control RORγT and RORγ expression, respectively. Similar to RORγT, RORγ is selectively expressed in Th17 cells and is effective in specifying the Th17 phenotype. c-Rel-deficient T cells are significantly compromised in Th17 differentiation, and c-Rel-deficient mice are defective in Th17 responses, and resistant to autoimmune diseases. Thus, Th17 immunity is controlled by a c-Rel−RORγ−RORγT axis, and strategies targeting Rel/NF-κB can be effective for controlling Th17 cell-mediated diseases.

IkappaBalpha/IkappaBepsilon deficiency reveals that a critical NF-kappaB dosage is required for lymphocyte survival

In most cells, the NF-kappaB transcription factor is sequestered in the cytoplasm by interaction with inhibitory proteins, the IkappaBs. Here, we show that combined IkappaBalpha/IkappaBepsilon deficiency in mice leads to neonatal death, elevated kappaB binding activity, overexpression of NF-kappaB target genes, and disruption of lymphocyte production. In IkappaBalpha/IkappaBepsilon-deficient fetuses, B220+IgM+ B cells and single-positive T cells die by apoptosis. In adults, IkappaBalpha-/-IkappaBepsilon-/- reconstituted chimeras exhibit a nearly complete absence of T and B cells that is not rescued by cotransfer with wild-type bone marrow. These findings demonstrate that IkappaBs tightly control NF-kappaB activity in vivo and that increased NF-kappaB activity intrinsically impairs lymphocyte survival. Because reduction or rise of NF-kappaB activity leads to similar dysfunction, they also reveal that only a narrow window of NF-kappaB activity is tolerated by lymphocytes.

The combined absence of the transcription factors Rel and RelA leads to multiple hemopoietic cell defects

Individual Rel/NF-kappaB transcription factors, although dispensable for the development and maturation of most hemopoietic cells, are critical regulators of normal immune function. Redundancy among these proteins prompted us to examine the role of Rel and RelA in hemopoiesis by using mice that lack both subunits. Because of the death of double-mutant fetuses at day 13.5 of gestation (E13.5), E12 fetal liver hemopoietic progenitors were used for in vitro cultures and for repopulating stem cell studies in lethally irradiated normal recipient mice. Most striking, Rel/RelA-deficient hemopoietic precursors failed to promote the survival of myeloablated mice. This phenotype was associated with several defects including a reduction of spleen colony-forming unit progenitors, impaired erythropoiesis, and a deregulated expansion of granulocytes. In vitro progenitor assays also revealed that Rel or RelA serves an antiapoptotic role during monocyte differentiation. Despite the combined loss of Rel and RelA leading to these hemopoietic defects, c-rel(-/-)rela(-/-) stem cells contributed to the development of all lineages in mice engrafted with double-mutant fetal liver cells and normal bone marrow cells, albeit in a reduced fashion compared with controls. Collectively, these data indicate the loss of Rel and RelA does not appear to affect pluripotent stem cells; rather, Rel and RelA serve redundant functions in regulating differentiation and survival of committed progenitors in multiple hemopoietic lineages.

The methylglutamate, SYM 2081, is a potent and highly selective agonist at kainate receptors

The methylglutamate analog (2S,4R)-4-methylglutamate (SYM 2081) has been shown to potently displace high affinity [3H]kainate binding to cortical tissue and to recombinant kainate receptors, and to evoke rapidly desensitizing responses in electrophysiological recordings. We have used two electrode voltage clamp recordings to compare the potency and efficacy of SYM 2081 with other alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionate (AMPA)/kainate receptor agonists at homomeric kainate and AMPA receptors expressed in Xenopus oocytes. In the presence of concanavalin A to reduce agonist induced desensitization at kainate receptors, SYM 2081 was a potent agonist at homomeric kainate receptors composed of the GluR5 and GluR6 subunit, with an EC50 of 0.12 +/- 0.02 and 0.23 +/- 0.01 microM, respectively. SYM 2081 was highly selective for kainate receptors, the EC50 for activation of AMPA receptors composed of the GluR1 and GluR3 subunits was 132 +/- 44 and 453 +/- 57 microM, respectively. Other methylglutamate analogs were tested for kainate receptor agonist activity. Methylglutamate compounds with the methyl group at the 2 or 3 position of glutamate were inactive indicating that positioning of the methyl group at the 4 position was essential for agonist activity. Of the four stereoisomers of 4-methylglutamate, SYM 2081 (2S,4R) was the most potent agonist. The (2R,4R) isomer was estimated to be 20-fold and the (2S,4S)-isomer approximately 1000-fold less potent than SYM 2081. These results indicate that SYM 2081 is a potent and selective agonist at kainate receptors, and thus will be a useful ligand for evaluating the role of kainate receptors in central nervous system function and disease.