Atherosclerosis, the main underlying pathology of cardiovascular disease, is a chronic inflammatory disease characterized by lipid accumulation and immune cell responses in the vascular wall,... Show moreAtherosclerosis, the main underlying pathology of cardiovascular disease, is a chronic inflammatory disease characterized by lipid accumulation and immune cell responses in the vascular wall, resulting in plaque formation. It is well-known that atherosclerosis prevalence and manifestation vary by sex. However, sexual dimorphism in the immune landscape of atherosclerotic plaques has up to date not been studied at high-resolution. In this study, we investigated sex-specific differences in atherosclerosis development and the immunological landscape of aortas at single-cell level in aged Ldlr-/- mice.We compared plaque morphology between aged male and female chow diet-fed Ldlr-/- mice (22 months old) with histological analysis. Using single-cell RNA-sequencing and flow cytometry on CD45+ immune cells from aortas of aged Ldlr-/- mice, we explored the immune landscape in the atherosclerotic environment in males and females.We show that plaque volume is comparable in aged male and female mice, and that plaques in aged female mice contain more collagen and cholesterol crystals, but less necrotic core and macrophage content compared to males. We reveal increased immune cell infiltration in female aortas and found that expression of pro-atherogenic markers and inflammatory signaling pathways was enriched in plaque immune cells of female mice. Particularly, female aortas show enhanced activation of B cells (Egr1, Cd83, Cd180), including age-associated B cells, in addition to an increased M1/M2 macrophage ratio, where Il1b+ M1-like macrophages display a more pro-inflammatory phenotype (Nlrp3, Cxcl2, Mmp9) compared to males. In contrast, increased numbers of age-associated Gzmk+CD8+ T cells, dendritic cells, and Trem2+ macrophages were observed in male aortas.Altogether, our findings highlight that sex is a variable that contributes to immunological differences in the atherosclerotic plaque environment in mice and provide valuable insights for further preclinical studies into the impact of sex on the pathophysiology of atherosclerosis. Show less
Smit, V.; Mol, J. de; Schaftenaar, F.H.; Depuydt, M.A.C.; Postel, R.J.; Smeets, D.: Verheijen, F.W.M.; ... ; Foks, A.C. 2023
Aging is a dominant driver of atherosclerosis and induces a series of immunological alterations, called immunosenescence. Given the demographic shift towards elderly, elucidating the unknown impact... Show moreAging is a dominant driver of atherosclerosis and induces a series of immunological alterations, called immunosenescence. Given the demographic shift towards elderly, elucidating the unknown impact of aging on the immunological landscape in atherosclerosis is highly relevant. While the young Western diet-fed Ldlr-deficient (Ldlr-/-) mouse is a widely used model to study atherosclerosis, it does not reflect the gradual plaque progression in the context of an aging immune system as occurs in humans.\nHere, we show that aging promotes advanced atherosclerosis in chow diet-fed Ldlr-/- mice, with increased incidence of calcification and cholesterol crystals. We observed systemic immunosenescence, including myeloid skewing and T-cells with more extreme effector phenotypes. Using a combination of single-cell RNA-sequencing and flow cytometry on aortic leukocytes of young versus aged Ldlr-/- mice, we show age-related shifts in expression of genes involved in atherogenic processes, such as cellular activation and cytokine production. We identified age-associated cells with pro-inflammatory features, including GzmK+CD8+ T-cells and previously in atherosclerosis undefined CD11b+CD11c+T-bet+ age-associated B-cells (ABCs). ABCs of Ldlr-/- mice showed high expression of genes involved in plasma cell differentiation, co-stimulation, and antigen presentation. In vitro studies supported that ABCs are highly potent antigen-presenting cells. In cardiovascular disease patients, we confirmed the presence of these age-associated T- and B-cells in atherosclerotic plaques and blood.\nCollectively, we are the first to provide comprehensive profiling of aged immunity in atherosclerotic mice and reveal the emergence of age-associated T- and B-cells in the atherosclerotic aorta. Further research into age-associated immunity may contribute to novel diagnostic and therapeutic tools to combat cardiovascular disease. Show less
Atherosclerosis is characterized by the accumulation of lipids and immune cells, including mast cells and B cells, in the arterial wall. Mast cells contribute to atherosclerotic plaque growth and... Show moreAtherosclerosis is characterized by the accumulation of lipids and immune cells, including mast cells and B cells, in the arterial wall. Mast cells contribute to atherosclerotic plaque growth and destabilization upon active degranulation. The FcεRI-IgE pathway is the most prominent mast cell activation route. Bruton's Tyrosine Kinase (BTK) is involved in FcεRI-signaling and may be a potential therapeutic target to limit mast cell activation in atherosclerosis. Additionally, BTK is crucial in B cell development and B-cell receptor signaling. In this project, we aimed to assess the effects of BTK inhibition on mast cell activation and B cell development in atherosclerosis. In human carotid artery plaques, we showed that BTK is primarily expressed on mast cells, B cells and myeloid cells. In vitro, BTK inhibitor Acalabrutinib dose-dependently inhibited IgE mediated activation of mouse bone marrow derived mast cells. In vivo, male Ldlr-/- mice were fed a high-fat diet for eight weeks, during which mice were treated with Acalabrutinib or control solvent. In Acalabrutinib treated mice, B cell maturation was reduced compared to control mice, showing a shift from follicular II towards follicular I B cells. Mast cell numbers and activation status were not affected. Acalabrutinib treatment did not affect atherosclerotic plaque size or morphology. In advanced atherosclerosis, where mice were first fed a high-fat diet for eight weeks before receiving treatment, similar effects were observed. Conclusively, BTK inhibition by Acalabrutinib alone did neither affect either mast cell activation nor early- and advanced atherosclerosis, despite the effects on follicular B cell maturation. Show less
Currently immunomodulatory compounds are under investigation for use in patients with cardiovascular disease, caused by atherosclerosis. These trials, using recurrent cardiovascular events as... Show moreCurrently immunomodulatory compounds are under investigation for use in patients with cardiovascular disease, caused by atherosclerosis. These trials, using recurrent cardiovascular events as endpoint, require enrollment of large patient groups. We investigated the effect of key risk factors for atherosclerosis development, ageing and smoking, on the immune system, with the objective to identify biomarkers differentiating between human populations, and potentially serving as endpoints for future phase 1B trials with immunomodulatory compounds. Blood was collected from young healthy volunteers (aged 18-25 years, n=30), young smokers (18-25 years, n=20), elderly healthy volunteers (>60 years, n=20), heavy smokers (>45 years, 15 packyears, n=11) and patients with stable coronary artery disease (CAD) (>60 years, n=27). Circulating immune cell subsets were characterized by flow cytometry, and collected plasma was evaluated by proteomics (Olink). Clear ageing effects were observed, mostly illustrated by a lower level in CD8+ and naïve CD4+ and CD8+ T cells, with an increase in CD4+ and CD8+ effector memory T cells in elderly healthy volunteers compared to young healthy volunteers. Heavy smokers showed a more inflammatory cellular phenotype, especially a shift in Th1/Th2 ratio: higher Th1 and lower Th2 percentages compared to young healthy volunteers. A significant decrease in circulating atheroprotective oxLDL-specific IgM was found in patients with CAD compared to young healthy volunteers. Elevated pro-inflammatory and chemotactic proteins TREM1 and CCL11 were observed in elderly volunteers compared to young volunteers. In addition, heavy smokers had an increase in pro-inflammatory cytokine IL-6 and lysosomal protein LAMP3. These data show that ageing and smoking are associated with an inflammatory immunophenotype, and that heavy smokers or aged individuals may serve as potential populations for future clinical trials investigating immunomodulatory drugs targeted for cardiovascular disease. Show less
Postel, R.J.; Smit, V.; De Mol, J.; Bernabé Kleijn, M.N.A.; De Jong, M.J.M.; Delfos, L.; ... ; Foks, A.C. 2022
Increasing evidence has shown that immune checkpoint molecules of the T-cell immunoglobulin and mucin domain (Tim) family are associated with diverse physiologic and pathologic processes. Previous... Show moreIncreasing evidence has shown that immune checkpoint molecules of the T-cell immunoglobulin and mucin domain (Tim) family are associated with diverse physiologic and pathologic processes. Previous studies of the role of Tim-1 in atherosclerosis using anti-Tim-1 antibodies have yielded contradictory results. We thus aimed to investigate atherosclerosis development in Tim-1 deficient mice.Mice with a specific loss of the Tim-1 mucin-domain (Tim-1Δmucin) and C57BL/6 (WT) mice received a single injection of a recombinant adeno-associated virus encoding murine Pcsk9 (rAAV2/8-D377Y-mPcsk9) and were fed a Western type diet for 13 weeks to introduce atherosclerosis.Tim-1Δmucin mice developed significantly larger lesions in the aortic root compared to WT mice, with significantly more macrophages and a trend towards a larger necrotic core. Furthermore, Tim-1Δmucin mice showed a significant loss of IL-10+ B cells and regulatory B cell subsets and increased pro-atherogenic splenic follicular B cells compared to WT mice. Moreover, Tim-1Δmucin mice displayed a dramatic reduction in Th2-associated immune response compared to controls but we did not observe any changes in humoral immunity.In summary, Tim-1Δmucin mice displayed a profound impairment in IL-10+ B cells and an imbalance in the Th1/Th2 ratio, which associated with exacerbated atherosclerosis. Show less
Mol, J. de; Postel, R.J.; Smit, V.; Bernabé Kleijn, M.N.A.; Bot, I.; Kuiper, J.; Foks, A.C. 2022
Aging is associated with changes in the composition and function of the immune system, such as decreased B cell numbers and reduced antibody responses (1). In addition, aging is related to an... Show moreAging is associated with changes in the composition and function of the immune system, such as decreased B cell numbers and reduced antibody responses (1). In addition, aging is related to an increased incidence of inflammatory diseases, such as the lipid-driven chronic inflammatory disease atherosclerosis, the main underlying cause of cardiovascular disease (2). B cells play a major role in atherosclerosis progression by antibody secretion, antigen presentation and T cell regulation. Different B cell subsets, with either proatherogenic or antiatherogenic properties, have been identified in atherosclerosis, but the impact of aging on B cells during atherosclerosis remains to be elucidated. In contrast to young atherosclerotic mice where few B cells are found within the plaque, single cell RNA sequencing and flow cytometry data from our group revealed that B cells are one of the most dominant leukocytes present in atherosclerotic aortas from naturally aged LDLr-/- mice. In this study, we aimed to gain further insights into the role of these aged B cells on T cell immunity in atherosclerosis by depleting B cells in aged atherosclerotic mice. Aged (85-95 weeks) atherosclerotic male LDLr-/- mice were kept on a chow diet for six weeks, during which the mice received 250 μg B cell-depleting anti-CD20 antibody (Genentech) (n=12) or 250 μg rat IgG2a isotype control (n=12) once a week intraperitoneally. Mice that received the anti-CD20 antibody showed effective B cell depletion in the blood and lymphoid organs, such as the spleen and lymph nodes, but also locally in the atherosclerotic plaque. In addition, B cell depleted mice showed a significant increase in the percentage of T-bet expressing CD4+ T cells in aortic plaques compared to control mice (αCD20: 25.05±2.88% vs. ctrl: 15.94±2.14%, p<0.05). Furthermore, the percentage of RORyt+ and IL-17+ CD4+ T cells in the spleen and heart draining lymph nodes was increased after B cell depletion, indicating a shift towards Th17 differentiation.Collectively, we show that CD20+ B cell depletion in aged LDLr-/- mice skews CD4+ T cells towards a Th1 phenotype in the atherosclerotic plaque and towards a Th17 phenotype in lymphoid organs, suggesting a protective role for aged B cells in atherosclerosis. However, B cells are a heterogeneous population and further research should elucidate whether aged B cells exert a pro- or anti-atherogenic role. In conclusion, our results indicate that aged B cells have an important function in CD4+ T cell differentiation and could be attractive targets to combat age-related cardiovascular disease. Show less
Cytotoxic CD4+ T cells have previously been found in peripheral blood of patients with coronary artery disease (1), however their occurrence in atherosclerotic plaques and their association with... Show moreCytotoxic CD4+ T cells have previously been found in peripheral blood of patients with coronary artery disease (1), however their occurrence in atherosclerotic plaques and their association with the pathophysiology of atherosclerosis has not been established. Single-cell RNA sequencing was performed on human carotid atherosclerotic plaques of 18 patients to identify specific T cell populations (2). Next, human femoral and carotid atherosclerotic plaques (n=95) and matched blood samples (n=49) were analyzed by flow cytometry for the presence of CD4+GZMB+ T cells. Plaque morphology was assessed by Movat’s Pentachrome staining. A distinct cytotoxic GZMB+ PRF1+ CD28- CD4+ T cell cluster was identified using single-cell RNA sequencing. Furthermore, flow cytometry analysis showed that the percentage of GZMB+CD4+ T cells was significantly elevated in plaque compared to blood (Blood: 12.17±2.0 vs. Plaque: 17.40±1.0; P=0.0002). Moreover, a significant positive correlation was observed between the percentage of GZMB+CD4+ T cells in blood versus plaque (P=0.031). In line with the proinflammatory character of these cells, we found a positive association of GZMB+CD4+ T cells (P=0.036) with necrotic core size, whereas no correlation was found with this subtype in the circulation. In this study we have shown an enrichment of cytotoxic CD4+ T cells in atherosclerotic lesions, which positively correlate with necrotic core size. Future studies are aimed at elucidating the role of these cells in advanced atherosclerosis. Show less
Signaling through the coinhibitory programmed death (PD)-1/PD-L1 pathway regulates T cell responses and can inhibit ongoing immune responses. Inflammation is a key process in the development of... Show moreSignaling through the coinhibitory programmed death (PD)-1/PD-L1 pathway regulates T cell responses and can inhibit ongoing immune responses. Inflammation is a key process in the development of atherosclerosis, the underlying cause for the majority of cardiovascular diseases. Dampening the excessive immune response that occurs during atherosclerosis progression by promoting PD-1/PD-L1 signaling may have a high therapeutic potential to limit disease burden. In this study we therefore aimed to assess whether an agonistic PD-1 antibody can diminish atherosclerosis development.Ldlr-/- mice were fed a western-type diet (WTD) while receiving 100 μg of an agonistic PD-1 antibody or control vehicle twice a week. Stimulation of the PD-1 pathway delayed the WTD-induced monocyte increase in the circulation up to 3 weeks and reduced T cell activation and proliferation. CD4+ T cell numbers in the atherosclerotic plaque were reduced upon PD-1 treatment. More specifically, we observed a 23% decrease in atherogenic IFNγ-producing splenic CD4+ T cells and a 20% decrease in cytotoxic CD8+ T cells, whereas atheroprotective IL-10 producing CD4+ T cells were increased with 47%. Furthermore, we found an increase in regulatory B cells, B1 cells and associated atheroprotective circulating oxLDL-specific IgM levels in agonistic PD-1-treated mice. This dampened immune activation following agonistic PD-1 treatment resulted in reduced atherosclerosis development (p < 0.05).Our data show that stimulation of the coinhibitory PD-1 pathway inhibits atherosclerosis development by modulation of T- and B cell responses. These data support stimulation of coinhibitory pathways as a potential therapeutic strategy to combat atherosclerosis. Show less
Aims Human epidermal growth factor receptor 2 (HER2) amplification in endometrial cancer (EC) is almost completely confined to the p53-abnormal (p53abn) molecular subtype and independent of... Show moreAims Human epidermal growth factor receptor 2 (HER2) amplification in endometrial cancer (EC) is almost completely confined to the p53-abnormal (p53abn) molecular subtype and independent of histological subtype. HER2 testing should therefore be molecular subtype-directed. However, the most optimal approach for HER2 testing in EC has not been fully established. Therefore, we developed an EC-specific HER2 immunohistochemistry (IHC) scoring method and evaluated its reproducibility and performance to establish an optimal diagnostic HER2 testing algorithm for p53abn EC. Methods and results HER2 IHC slides of 78 p53abn EC were scored by six gynaecopathologists according to predefined EC-specific IHC scoring criteria. Interobserver agreement was calculated using Fleiss' kappa and the first-order agreement coefficient (AC1). The consensus IHC score was compared with HER2 dual in-situ hybridisation (DISH) results. Sensitivity and specificity were calculated. A substantial interobserver agreement was found using three- or two-tiered scoring [kappa = 0.675, 95% confidence interval (CI) = 0.633-0.717; AC1 = 0.723, 95% CI = 0.643-0.804 and kappa = 0.771, 95% CI = 0.714-0.828; AC1 = 0.774, 95% CI = 0.684-0.865, respectively]. Sensitivity and specificity for the identification of HER2-positive EC was 100 and 97%, respectively, using a HER2 testing algorithm that recommends DISH in all cases with moderate membranous staining in >10% of the tumour (IHC+). Performing DISH on all IHC-2+ and -3+ cases yields a sensitivity and specificity of 100%. Conclusions Our EC-specific HER2 IHC scoring method is reproducible. A screening strategy based on IHC scoring on all cases with subsequent DISH testing on IHC-2+/-3+ cases has perfect test accuracy for identifying HER2-positive EC. Show less
Tesfai, F.M.; Kroep, J.R.; Gaarenstroom, K.; Kroon, C. de; Loenhout, R. van; Smit, V.; ... ; Beltman, J.J. 2020
Objective To assess the feasibility, safety, oncological, and obstetric outcomes in patients with cervical tumors >2 cm treated with neoadjuvant chemotherapy in preparation for abdominal radical... Show moreObjective To assess the feasibility, safety, oncological, and obstetric outcomes in patients with cervical tumors >2 cm treated with neoadjuvant chemotherapy in preparation for abdominal radical trachelectomy. Methods A retrospective analysis of patients with cervical cancer >2 cm (up to 6 cm) was conducted in patients who were selected to receive neoadjuvant chemotherapy before abdominal radical trachelectomy. Surgical and clinical outcomes were examined in relation to radiological and pathological results. In addition, obstetric outcomes were described. The Mann-Whitney U test and Fisher's exact test were performed to compare radiological findings between successful and unsuccessful abdominal radical trachelectomy procedures. International Federation of Gynecology and Obstetrics (FIGO) 2009 staging classification was used for this study. Results A total of 19 women were treated with neoadjuvant chemotherapy for cervical tumors >2 cm at our institution between May 2006 and July 2018. The median age was 28 years (range 19-36). The distribution of FIGO stages was seven patients stage IB1 (37%), 10 patients stage IB2 (53%), and two patients (10%) stage IIA. Mean clinical tumor size was 4.4 cm (range 3.5-6.0). Histology revealed 74% cases of squamous cell carcinoma. The remaining patients had adenocarcinoma (21%) and only one patient had clear cell adenocarcinoma (5%). Chemotherapy consisted of six weekly cycles of cisplatin (70 mg/m(2)) and paclitaxel (70 mg/m(2)). In 15 of the 19 patients (74%) fertility was successfully preserved. In the four patients in whom fertility preservation failed, one patient had stable disease after three cycles and did not meet the criteria for fertility-sparing surgery and three patients had intra- or post-operative indications for adjuvant therapy. Three of the 19 patients (15.7%) had a relapse, two of whom died. One case was in the group of successful abdominal radical trachelectomy. Conclusion Neoadjuvant chemotherapy followed by fertility-sparing surgery may be a feasible and safe option in select patients with cervical tumors >2 cm. Unfavorable prognostic factors are defined as non-responsiveness and non-squamous pathology, which can help in patient selection for fertility-sparing surgery. Show less
Histopathological evaluation including subtyping and grading is the current cornerstone for endometrial cancer (EC) classification. This provides clinicians with prognostic information and input... Show moreHistopathological evaluation including subtyping and grading is the current cornerstone for endometrial cancer (EC) classification. This provides clinicians with prognostic information and input for further treatment recommendations. Nonetheless, patients with histologically similar ECs may have very different outcomes, notably in patients with high-grade endometrial carcinomas. For endometrial cancer, four molecular subgroups have undergone extensive studies in recent years:POLEultramutated (POLEmut), mismatch repair-deficient (MMRd), p53 mutant (p53abn) and those EC lacking any of these alterations, referred to as NSMP (non-specific molecular profile). Several large studies confirm the prognostic relevance of these molecular subgroups. However, this 'histomolecular' approach has so far not been implemented in clinical routine. The ongoing PORTEC4a trial is the first clinical setting in which the added value of integrating molecular parameters in adjuvant treatment decisions will be determined. For diagnostics, the incorporation of the molecular parameters in EC classification will add a level of objectivity which will yield biologically more homogeneous subclasses. Here we illustrate how the management of individual EC patients may be impacted when applying the molecular EC classification. We describe our current approach to the integrated diagnoses of EC with a focus on scenarios with conflicting morphological and molecular findings. We also address several pitfalls accompanying the diagnostic implementation of molecular EC classification and give practical suggestions for diagnostic scenarios. Show less
Douna, H.; Smit, V.; Puijvelde, G. van; Binder, C.; Bot, I.; Kuchroo, V.; ... ; Foks, A. 2019
Increasing evidence has shown that immune checkpoint molecules of the T-cell immunoglobulin and mucin domain (TIM) family are associated with diverse physiologic and pathologic pro-... Show moreIncreasing evidence has shown that immune checkpoint molecules of the T-cell immunoglobulin and mucin domain (TIM) family are associated with diverse physiologic and pathologic pro- cesses. Previous studies investigating TIM-1 in atherosclerosis using anti- TIM-1 antibodies have yielded contradictory results. We thus aimed to investigate atherosclerosis development in TIM-1 deficient mice. In this study, mice with a specific loss of the TIM-1 mucin- domain (TIM-1Dmucin) were used. TIM-1Dmucin mice and control WT (C57/Bl6) mice received a single i.v. injection of 5x1011 rAAV8-D377Y-mPCSK9 vector genomes and were fed a Western-type diet for 13 weeks.TIM-1Dmucin mice developed significantly larger lesions in theaortic root and arch compared to WT mice. These lesions were composed of significantly more macrophages and showed a trend towards a larger necrotic core. The exacerbated atherosclerosis in TIM-1Dmucin mice was associated with a significant loss of IL-10+ B cells and regulatory B cell subsets compared to WT mice. TIM-1Dmucin mice also showed an increase in splenic and circulating leukocytes compared to WT mice, which was caused by an increase in B and CD4+ T cells in the spleen, while no specific leukocyte population was changed in the circulation. TIM- 1Dmucin mice also displayed a dramatic reduction in Th2-associated immune response compared to controls but no changes in humoral immune response.In summary, TIM-1Dmucin mice displayed a profoundimpairment in IL-10+ B cells and an imbalance in the Th1/Th2 ratio, whichassociated with exacerbated atherosclerosis. Show less
Jonge, M. de; Auguste, A.; Schouten, P.; Kroon, C. de; Meijers, M.; Haar, N. ter; ... ; Bosse, T. 2017
