Epithelial IFNγ signalling and compartmentalized antigen presentation orchestrate gut immunity

All nucleated cells express major histocompatibility complex I and interferon-γ (IFNγ) receptor1, but an epithelial cell-specific function of IFNγ signalling or antigen presentation by means of major histocompatibility complex I has not been explored. We show here that on sensing IFNγ, colonic epithelial cells productively present pathogen and self-derived antigens to cognate intra-epithelial T cells, which are critically located at the epithelial barrier. Antigen presentation by the epithelial cells confers extracellular ATPase expression in cognate intra-epithelial T cells, which limits the accumulation of extracellular adenosine triphosphate and consequent activation of the NLRP3 inflammasome in tissue macrophages. By contrast, antigen presentation by the tissue macrophages alongside inflammasome-associated interleukin-1α and interleukin-1β production promotes a pathogenic transformation of CD4+ T cells into granulocyte-macrophage colony-stimulating-factor (GM-CSF)-producing T cells in vivo, which promotes colitis and colorectal cancer. Taken together, our study unravels critical checkpoints requiring IFNγ sensing and antigen presentation by epithelial cells that control the development of pathogenic CD4+ T cell responses in vivo.

Abstract 1797: Bcl-2 up-regulation mediates taxane resistance downstream of APC loss

Patients with triple negative breast cancer (TNBC) are treated with traditional chemotherapy, such as paclitaxel (PTX). Despite the efficacy of taxanes, many tumors will recur due to drug resistance. Therefore, the need to understand the mechanism behind drug resistance is critical to improve patient outcome and survival. Our lab was the first to show that loss of the Adenomatous Polyposis Coli (APC) tumor suppressor caused resistance to PTX in the MDA-MB-157 human TNBC cell line. In the absence of APC, apoptosis induction was decreased, as measured through cleaved caspase 3 and annexin/PI staining. To understand the molecular mechanisms behind APC-mediated PTX response, we analyzed the BCL-2 family of proteins and found a robust increase of the pro-survival family member, Bcl-2. The BH3 mimetic, ABT-199 (Venetoclax), which specifically targets Bcl-2, has been used as a single or combination therapy in multiple hematologic malignancies. In addition, ABT-199 has shown promise in multiple subtypes of breast cancer. Therefore, we used ABT-199 in combination with PTX to address the hypothesis that APC-induced Bcl-2 increase is responsible for PTX resistance. Combination treatment in three CRISPR-mediated APC knockout TNBC cell lines (MDA-MB-157, MDA-MB-231, and SUM159) caused changes in cell proliferation and apoptosis. Combined, these data suggest restored sensitivity to PTX using ABT-199. Our studies are the first to show that Bcl-2 inhibition can restore PTX-sensitivity in APC mutant breast cancer cells. These studies are critical to advance better treatment regimens in patients with TNBC.

Citation Format: Sara Maloney, Sarah Zabala, Grace Richmond, Jenifer R. Prosperi. Bcl-2 up-regulation mediates taxane resistance downstream of APC loss [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1797.

Sildenafil prevents the increase of extravascular lung water and pulmonary hypertension after meconium aspiration in newborn piglets

Meconium aspiration syndrome causes respiratory failure after birth and in vivo monitoring of pulmonary edema is difficult. The objective of the present study was to assess hemodynamic changes and edema measured by transcardiopulmonary thermodilution in low weight newborn piglets. Additionally, the effect of early administration of sildenafil (2 mg/kg vo, 30 min after meconium aspiration) on this critical parameter was determined in the meconium aspiration syndrome model. Thirty-eight mechanically ventilated anesthetized male piglets (Sus scrofa domestica) aged 12 to 72 h (1660 ± 192 g) received diluted fresh human meconium in the airway in order to evoke pulmonary hypertension (PHT). Extravascular lung water was measured in vivo with a PiCCO monitor and ex vivo by the gravimetric method, resulting in an overestimate of 3.5 ± 2.3 mL compared to the first measurement. A significant PHT of 15 Torr above basal pressure was observed, similar to that of severely affected humans, leading to an increase in ventilatory support. The vascular permeability index increased 57%, suggesting altered alveolocapillary membrane permeability. Histology revealed tissue vessel congestion and nonspecific chemical pneumonitis. A group of animals received sildenafil, which prevented the development of PHT and lung edema, as evaluated by in vivo monitoring. In summary, the transcardiopulmonary thermodilution method is a reliable tool for monitoring critical newborn changes, offering the opportunity to experimentally explore putative therapeutics in vivo. Sildenafil could be employed to prevent PHT and edema if used in the first stages of development of the disease.

Neutropenia, thrombocytopenia and hepatic injury associated with dexketoprofen trometamol therapy in a previously healthy 35-year-old woman

This case report describes a previously healthy 35-year-old woman, with an episode of fever, neutropenia, thrombocytopenia and elevation of biochemical markers of liver injury, 10 days after beginning drug therapy with dexketoprofen trometamol. Infectious and autoimmune causes of neutropenia, and viral or autoimmune hepatitis were excluded. The resolution following withdrawal of dexketoprofen trometamol confirms the possibility of an adverse drug reaction.

Alfuzosin-induced hepatotoxicity

Drug-induced hepatic injury is a potential complication of virtually all drugs because the liver is central to the metabolic disposition of almost all drugs, although precise mechanisms often are unknown. We report a case of severe acute mixed hepatitis (cholestatic and hepatocellular), probably induced by alfuzosin. This event has not been reported previously (MEDLINE 1990, March 1999). Viral causes, autoimmune hepatitis and biliary tree obstruction were excluded. After discontinuation of the drug, liver function test results returned to normal.

Influence of calcium antagonist drugs in myasthenia gravis in the elderly

A number of drugs have been reported to cause neuromuscular blockade and/or to increase weakness in myasthenia gravis. We report on two patients, treated with felodipine and nifedipine for arterial hypertension, who presented with an exacerbation of their myasthenia gravis and a myasthenic syndrome or exacerbation of myasthenia gravis, respectively. The mechanism of action of calcium antagonist drugs at the neuromuscular junction is not yet well established, but it could be located at both presynaptic and postsynaptic levels.

[Delay time to arrive at the hospital of 275 patients with acute myocardial infarction. Study form the province of Teruel (1991-1994)]

BACKGROUND

To study the delay time to arrive of the hospital and its relation with any variables, of patients with acute myocardial infarction from the province of Teruel (Spain).

PATIENTS AND METHODS

A prospective study was carried out from January 1991 to October 1994. We included patients who were diagnosticated of the acute myocardial infarction (212 men and 63 women). We considered the time between the thoracic pain and their arrive at the urgency service. We based the diagnosis in clinical, electrocardiographic and enzymatic criteria.

RESULTS

The mean delay time was 8 h 46 m. The 66.5% arrives before 6 hours. We found no differences between rural or urban patients. The delay time was minor in men than women (7 h 12 m versus 14 h, p = 0.0019), in younger (< 65 years old) than in the older (6 h 3 m versus 10 h 18 m, p = 0.0278), and in those who were admitted to the ICU (7h 16 m versus 20 h 33 m, p = 0.0001). Was longer in patients with arterial hypertension and diabetes. Was minor in patients with dyslipemia and tobacco habit. Many patients to arrive of the hospital by physician order and with own vehicles, it took less time arrive at the hospital than by ambulance (8 h 30 m versus 18 h, p < 0.05). The medium delay in the emergency area was 2 h 35 m. The delay time was longer in patients who died (16 h versus 7h 30 m, p = 0.0018) and in those who present more frequently cardiac failure.

CONCLUSIONS

The mean delay time to arrive at the hospital in patients with acute myocardial infarction from the province of Teruel (Spain) in unreasonable and in takes a poor prognosis, so we consider necessary to study the causes of this delay in order to correct them.

[Intestinal obstruction caused by foreign body in a patient with colon neoplasm]

A case of intestinal obstruction due to ingested "foreign body" (a patient's tooth) is described in an elderly man with cancer of the ascending colon, at that time, without clinical symptoms.