The systemic deletion of interleukin-1α reduces myocardial inflammation and attenuates ventricular remodeling in murine myocardial infarction

Myocardial inflammation following myocardial infarction (MI) is crucial for proper myocardial healing, yet, dysregulated inflammation may promote adverse ventricular remodeling and heart failure. IL-1 signaling contributes to these processes, as shown by dampened inflammation by inhibition of IL-1β or the IL-1 receptor. In contrast, the potential role of IL-1α in these mechanisms has received much less attention. Previously described as a myocardial-derived alarmin, IL-1α may also act as a systemically released inflammatory cytokine. We therefore investigated the effect of IL-1α deficiency on post-MI inflammation and ventricular remodeling in a murine model of permanent coronary occlusion. In the first week post-MI, global IL-1α deficiency (IL-1α KO mice) led to decreased myocardial expression of IL-6, MCP-1, VCAM-1, hypertrophic and pro-fibrotic genes, and reduced infiltration with inflammatory monocytes. These early changes were associated with an attenuation of delayed left ventricle (LV) remodeling and systolic dysfunction after extensive MI. In contrast to systemic Il1a-KO, conditional cardiomyocyte deletion of Il1a (CmIl1a-KO) did not reduce delayed LV remodeling and systolic dysfunction. In conclusion, systemic Il1a-KO, but not Cml1a-KO, protects against adverse cardiac remodeling after MI due to permanent coronary occlusion. Hence, anti-IL-1α therapies could be useful to attenuate the detrimental consequences of post-MI myocardial inflammation.

The Prembion® pre-biotic improves the impact of anti-CTLA4 immune checkpoint inhibitor in a murine model of malignant pleural mesothelioma

Objective

Immune checkpoint inhibition (ICI) therapy has revolutionized the outcome of certain cancers such as malignant pleural mesothelioma (MPM). However, patient responsiveness to this treatment remains unpredictable. Recently, a role for the gut microbiota composition has emerged for patients to generate a robust immune response against their tumors, following immunotherapy. Here, we studied the impact of Prembion®, a pre-biotic and modulator of the gut microbiota, on tumor control and lymphocyte infiltration in a murine MPM model treated by ICI.

Methods

Prembion® (diluted into drinking water) was administrated to BALBc mice for 14 days. These animals were then inoculated orthotopically with a syngeneic MPM cell line (AB12-luc cells injected in the pleura) and followed by bioluminescence imaging. We determined the tumor growth and mouse survival in different groups: untreated control, Prembion®, IgG control, anti-PDL-1, anti-CTLA4, Prembion®+anti-PDL-1 and Prembion®+anti-CTLA4. A correlation between tumor response/animal survival and MPM infiltration with CD8+ lymphocytes was also performed by immunohistochemistry.

Results

Prembion® was well tolerated and did not affect animal weight or activity. Interestingly, Prembion® was as effective as anti-PDL1 and anti-CTLA4 monotherapy on tumor control, prolonging survival by 4.0 ± 1.1 days compared to controls (p<0.05). Moreover Prembion® potentiated anti-CTLA4 efficacy with a significant improvement in mouse survival of the Prembion®+anti-CTLA4 compared to controls (3.6 ± 1.1 days, p<0.05). Additionally, this finding correlated with enhanced MPM infiltration by CD8+ lymphocytes compared to controls (p<0.05).

Conclusion

Prembion® positively regulated the adaptive immune response against MPM and helped to improve the impact of anti-CTLA4 ICI on MPM. Further work focusing on the gut microbiome changes induced by Prembion® are ongoing to better understand the mechanisms involved.

Photodynamique therapy relieves tumor vascular anergy and promotes immune cell trafficking in an orthotopic mouse model of malignant pleural mesothelioma

Objective

Malignant pleural mesothelioma (MPM) is a deadly disease with limited treatment options. Recently, dual immune checkpoint inhibition therapy (ICI) showed improved patient survival. However, only a fraction of patients were responsive to immunotherapy. One potential mechanism of MPM resistance to ICIs could be their endothelial anergy that hampers leukocyte trafficking to the tumor bulk. Here, we hypothesized that vascular-targeted low dose photodynamic therapy (L-PDT), treatment of MPM could relieve tumor endothelial anergy and improve immunotherapy efficacy.

Methods

Using an orthotopic syngeneic MPM murine model (AB12 cells injected in the pleura of BALB/c mice), we determined the impact of L-PDT on the endothelial expression of E-Selectin, a key molecule involved in leukocyte diapedesis by immunohistochemistry. Furthermore, to confirm the role of E-selectin, we determined the extravasation of effector T cells (CD8+/CD4+) by immunostaining in L-PDT treated tumors in the presence or absence of an E-selectin blocking antibody. Finally, we assessed tumor growth/survival of our MPM murine model treated with L-PDT alone or combined to ICIs.

Results

L-PDT pre-treatment enhanced MPM endothelial E-Selectin expression in vivo. The latter was associated with increased CD4+ and CD8+ lymphocyte infiltration of MPM following L-PDT which did not occur after E-Selectin blockade. Also, L-PDT pre-treatment of MPM influenced favorably tumor control, mouse survival and the impact of ICIs compared to controls.

Conclusion

L-PDT pre-treatment relieves endothelial anergy in MPM which improves antitumor immunity and response to ICI. This approach could constitute a promising pre-treatment option, in combination with ICIs, for the management of this deadly disease.

Intrapleural hyperthermic chemotherapy induces pro-immunogenic e-selectin expression in the vasculature of malignant pleural mesothelioma

Objective

Malignant pleural mesothelioma (MPM) is a deadly disease with dismal prognosis. Prior studies combining surgery with intrapleural hyperthermic chemotherapy (IPHC) have shown improved survivals in selected patients with MPM. However, the mechanisms by which IPHC acts on MPM and its microenvironment remains unknown. Here we focus on tumor endothelial adhesion molecule expression patterns.

Methods

First, we determined the impact of IPHC on MPM tumor and vascular compartments in vitro using a novel bioincubater for hyperthermic cell culture. The cytotoxicity of normo (37 °C) / hyperthermic (42 °C for 60 minutes) cisplatin/carboplatin therapies were evaluated on four MPM (MSTO211H, H-Meso, AE17 and AB12) and one endothelial (EC-RF24) cell lines at a minimum of 24 hours using a presto-blue assay. Second, we treated endothelial cells with IPHC (60 min, 42 °C at optimized cytotoxic concentrations) and determined its impact on pro-immunogenic adhesion molecule (E-selectin, VE-cadherin, VCAM and Connexin-43) expression at 24 hours by Western blot.

Results

Tumor and endothelial cell viability decreased with increasing doses of both chemotherapeutics but was not affected by hyperthermia (IC50 with or without hyperthermia of each cell line at 24 hours reported in Figure 1A). Interestingly, endothelial cell line IC50 was much higher than that of MPM tumor cells for both chemotherapeutics (Figure 1A). Pro-immunogenic adhesion molecule E-Selectin was increased at 24 hours by IPHC with both chemotherapeutics while VE-Cadherin, VCAM and Connexin-43 were not affected (Figure 1B).

Conclusion

Hyperthermia adds no cytotoxicity to intrapleural chemotherapy. However, IPHC favors pro-immunogenic endothelial E-selectin expression. The latter could help induce patient immunity against their MPM and improve survival. Confirmation of these findings in vivo is mandatory.

Application of Finite Element Analysis (FEA) for the simulation of release of additives from multilayer polymeric packaging structures

Computer programmes are available to predict, for consumer protection purposes, the migration of additives from a polymeric package during its contact with food. However most of these programs were developed to estimate migration only from single layer polymeric packaging under isothermal conditions. In this work a diffusion model was developed to simulate the migration from multilayer packaging and under non-isothermal temperature conditions, too. Finite Element Analysis (FEA) is used as a numerical approximation method to solve the diffusion equations describing such processes. The possibilities and limitations of the FEA method are presented and the correlation between experimental and computed results is discussed.

Coronary artery bypass operation in septuagenarians

Increasing numbers of patients more than 70 years old are at risk from coronary artery disease. The continued success of coronary artery bypass operation in selected patients provides impetus for applying this procedure to older patients as well. Our results indicate coronary artery operation is effective in older patients and has a low mortality (3% in our series). In patients in this age group, coronary artery operation can be combined with other procedures, when indicated, such as cardiac valve replacement or repair, left ventricular aneurysmectomy, carotid endarterectomy, and cholecystectomy.