T cell-derived interleukin-22 drives the expression of CD155 by cancer cells to suppress NK cell function and promote metastasis

Although T cells can exert potent anti-tumor immunity, a subset of T helper (Th) cells producing interleukin-22 (IL-22) in breast and lung tumors is linked to dismal patient outcome. Here, we examined the mechanisms whereby these T cells contribute to disease. In murine models of lung and breast cancer, constitutional and T cell-specific deletion of Il22 reduced metastases without affecting primary tumor growth. Deletion of the IL-22 receptor on cancer cells decreases metastasis to a degree similar to that seen in IL-22-deficient mice. IL-22 induced high expression of CD155, which bound to the activating receptor CD226 on NK cells. Excessive activation led to decreased amounts of CD226 and functionally impaired NK cells, which elevated the metastatic burden. IL-22 signaling was also associated with CD155 expression in human datasets and with poor patient outcomes. Taken together, our findings reveal an immunosuppressive circuit activated by T cell-derived IL-22 that promotes lung metastasis.

The risk of admission acute heart failure in ST-elevation myocardial infarction patients and air pollution with PM2.5

Introduction

Air pollution, in particular exposure to particulate matter fine particles of less than 2.5 microns in diameter (PM2.5), increases the risk of cardiovascular events. Short-term exposure (hours to few days prior) to increased PM2.5 levels even may help trigger ST-elevation myocardial infarction (STEMI) and heart failure exacerbation in susceptible individuals. The risk of vascular events is increased even in exposures below the current European air quality limit values (mean annual levels for PM2.5 less than 10μg/m3, 24-hour mean level less than 25μg/m3).

Purpose

To evaluate predictive role of PM2.5 levels ≥20 μg/m3 one day prior to hospital admission for the risk of admission acute heart failure (AAHF) in STEMI patients.

Methods

In 290 STEMI patients (100 women, 190 men, mean age 65.5±12.9 years), treated by primary percutaneous coronary intervention (PPCI) in 2018, we retrospectively registered the AAHF, defined as classes II-IV by Killip Kimbal classification. Additionally, we registered admission clinical data, potentially contributing to AAHF in STEMI patients such as gender, age ≥65 years, prior resuscitation, admission cTnI ≥5 μg/L (normal levels up to 0.045 μg/L), comorbidities, time to PPCI, and mean daily levels of PM2.5 ≥20 μg/m3 one day before admission. Mean daily, freely available, levels of PM2.5 were measured and registered by Chemical analytic laboratory of Environmental agency of Republic Slovenia. We evaluated the predictive role of admission data for admission AHF in STEMI patients.

Results

AAHF was observed in 34.5% of STEMI patients with the mean daily PM2.5 level 15.7±10.9 μg/m3 on the day before admission. PPCI was performed in 92.1% of all STEMI patients, in AAHF in 87.1% and in non-AAHF patients in 94.7% (p=0.037). AAHF in comparison to non-AAHF was associated significantly with female gender (50.5% vs 25.9%, p<0.001), age over 65 years (71.3% vs 45%, p<0.001), prior diabetes (33.7% vs 14.8%, p<0.001), left bundle branch block (LBBB) (10.9% vs 0.5%, <0.001), admission cTnI ≥5 μg/L (46.7% vs 25.9%, p<0.001) and mean daily levels of PM2.5 ≥20 μg/m3 one day before admission (31.7% vs 19%, p=0.020), but nonsignificantly with arterial hypertension, prior myocardial infarction, anterior STEMI and time to PPCI. Logistic regression demonstrated that significant independent predictors of AAHF were age over 65 years (OR 3.349, 95% CI 1.787 to 6.277, p<0.001), prior diabetes (OR 2.934, 95% CI 1.478 to 5.821, p=0.002), admission LBBB (OR 10.526, 95% CI 1.181 to 93.787, p=0.03), prior resuscitation (OR 3.221, 95% CI 1.336 to 7.761, p=0.009), admission cTnI ≥5μg/l (OR 2.984, 95% CI 1.618 to 5.502, p<0.001) and mean daily levels of PM2.5 ≥20 μg/m3 (OR 2.096, 95% CI 1.045 to 4.218, p=0.038) one day before admission.

Conclusion

Mean daily levels of PM2.5 ≥20μg/m3 one day before admission were among significant independent predictors of AAHF in STEMI patients.

Funding Acknowledgement

Type of funding sources: None.

STEMI patients in the first and second wave of COVID-19 pandemic in Slovenia

Introduction

Countries, severly hit by COVID-19 pandemic in spring 2020, reported reduced admissions and increased mortality of STEMI patients. The first wave of COVID-19 pandemic in Slovenia was mild, but in the second wave (October to December 2020) COVID-19 cases and fatalities significantly increased. To overcome the pandemic, restrictions to full lockdown, rapid redeployment and mobilization of healthcare resources, as well as reduction or delayed hospital admissions for acute non-communicable conditions were were undertaken.

Purpose

To evaluate STEMI admissions, the delay in treatment, complications and mortality of STEMI patients in the first and second wave of COVID-19 pandemic and comparison of data to 3 months (March-May) in 2019.

Methods

We retrospectively analysed the data of STEMI patients, admitted in March to May 2019 and in the first (March-May) and in the second wave (October-December) of the COVID-19 pandemic in 2020. We compared STEMI admissions, age, gender, comorbidities, time to primary coronary intervention (PPCI), the rate of PPCI, TIMI III flow after PPCI, prior resuscitations, hospital complications such as heart failure, arrhythmias, bleedings, acute kidney injury and mortality between 2019 and both waves of COVID-19 pandemic.

Results

Between STEMI patients in 2019 and patients in the first and the second wave of COVID-19 pandemic there were nonsignificant differences in STEMI admissions (90 patients vs 96 patients vs 81 patients), in gender, age, comorbidities, the rate of primary percutaneous intervention (PPCI, 94.4% vs 94.8% vs 91.4%), TIMI III flow after PPCI, anterior STEMI, in prior resuscitations (10% vs 10.4% vs 16%). Compared to 2019, admission acute heart failure was nonsignificantly increased in COVID-19 pandemic (30% vs 34.4% vs 39.5%). Within the first 3 hours of STEMI PPCI was performed nonsignificantly less likely in the first wave and significantly less likely in the second wave (35.5%* vs 30.2% vs 19.8%*, *p=0.037) in comparison to 2019. The incidence of acute kidney injury was similar in the first wave, but nonsignificantly increased in the second wave (6.6% vs 5.2% vs 9.8%), compared to 2019 and hospital infection was nonsignificantly increased in both COVID-19 periods (15.6% vs 20.8% vs 27.2%). In hospital heart failure was nonsignificantly increased in the first wave and significantly increased in the second one (23.3%* vs 27.1% vs 42%*, *p=0.015), as well as mitral regurgitation (10%* vs 18.8% vs 26.9%*, *p=0.008). Hospital mortality was nonsignificantly increased in bothe waves of the pandemic (8.9% vs 9.4% vs 13.6%).

Conclusions

In paralell to the increased severity of COVID-19 pandemic in the second wave there was less STEMI admissions, significantly less timely performed PPCI with significantly increased hospital heart failure, resulting in nonsignificantly increased hospital mortality.

Funding Acknowledgement

Type of funding sources: None.

Comparison of iron-reduced and iron-supplemented semisynthetic diets in T cell transfer colitis

Clinical observations in inflammatory bowel disease patients and experimental studies in rodents suggest that iron in the intestinal lumen derived from iron-rich food or oral iron supplementation could exacerbate inflammation and that iron depletion from the diet could be protective. To test the hypothesis that dietary iron reduction is protective against colitis development, the impact of iron reduction in the diet below 10 mg/kg on the course of CD4+ CD62L+ T cell transfer colitis was investigated in adult C57BL/6 mice. Weight loss as well as clinical and histological signs of inflammation were comparable between mice pretreated with semisynthetic diets with either < 10mg/kg iron content or supplemented with 180 mg/kg iron in the form of ferrous sulfate or hemin. Accumulation and activation of Ly6C^high monocytes, changes in dendritic cell subset composition and induction of proinflammatory Th1/Th17 cells in the inflamed colon were not affected by the iron content of the diets. Thus, dietary iron reduction did not protect adult mice against severe intestinal inflammation in T cell transfer induced colitis.

Epithelial-type systemic breast carcinoma cells with a restricted mesenchymal transition are a major source of metastasis

Carcinoma cells undergo epithelial-mesenchymal transition (EMT); however, contributions of EMT heterogeneity to disease progression remain a matter of debate. Here, we addressed the EMT status of ex vivo cultured circulating and disseminated tumor cells (CTCs/DTCs) in a syngeneic mouse model of metastatic breast cancer (MBC). Epithelial-type CTCs with a restricted mesenchymal transition had the strongest lung metastases formation ability, whereas mesenchymal-type CTCs showed limited metastatic ability. EpCAM expression served as a surrogate marker to evaluate the EMT heterogeneity of clinical samples from MBC, including metastases, CTCs, and DTCs. The proportion of epithelial-type CTCs, and especially DTCs, correlated with distant metastases and poorer outcome of patients with MBC. This study fosters our understanding of EMT in metastasis and underpins heterogeneous EMT phenotypes as important parameters for tumor prognosis and treatment. We further suggest that EpCAM-dependent CTC isolation systems will underestimate CTC numbers but will quantify clinically relevant metastatic cells.

Targeting interleukin-22 for cancer therapy

Interleukin-22 (IL-22) is a member of IL-10 family of cytokines. IL-22 induces proliferative and anti-apoptotic signaling pathways and production of anti-microbial molecules that enhance tissue regeneration and host defense. IL-22 has also been identified as a cancer-promoting cytokine since deregulation of the IL-22-IL-22R1 system is linked to different cancer entities including lung, breast, gastric, pancreatic and colon cancers. T cells and innate lymphoid cells are the main cellular sources of IL-22. Expression of its specific receptor IL-22R1 is restricted to the non-hematopoietic cells which makes the IL-22-IL-22R1 pathway an attractive target for anti-cancer therapy. For development of such therapies, a better understanding of IL-22 regulation in the tumor microenvironment is needed. We could recently decipher how cancer cells promote IL-22 production by memory T cells via induction of IL-1. Here we will discuss how this knowledge might contribute to developing therapies disregulating the IL-22 pathway for cancer immunotherapy.

Cancer cells induce interleukin-22 production from memory CD4+ T cells via interleukin-1 to promote tumor growth

IL-22 has been identified as a cancer-promoting cytokine that is secreted by infiltrating immune cells in several cancer models. We hypothesized that IL-22 regulation would occur at the interface between cancer cells and immune cells. Breast and lung cancer cells of murine and human origin induced IL-22 production from memory CD4+ T cells. In the present study, we found that IL-22 production in humans is dependent on activation of the NLRP3 inflammasome with the subsequent release of IL-1β from both myeloid and T cells. IL-1 receptor signaling via the transcription factors AhR and RORγt in T cells was necessary and sufficient for IL-22 production. In these settings, IL-1 induced IL-22 production from a mixed T helper cell population comprised of Th1, Th17, and Th22 cells, which was abrogated by the addition of anakinra. We confirmed these findings in vitro and in vivo in two murine tumor models, in primary human breast and lung cancer cells, and in deposited expression data. Relevant to ongoing clinical trials in breast cancer, we demonstrate here that the IL-1 receptor antagonist anakinra abrogates IL-22 production and reduces tumor growth in a murine breast cancer model. Thus, we describe here a previously unrecognized mechanism by which cancer cells induce IL-22 production from memory CD4+ T cells via activation of the NLRP3 inflammasome and the release of IL-1β to promote tumor growth. These findings may provide the basis for therapeutic interventions that affect IL-22 production by targeting IL-1 activity.