Cross‐talk between ovarian cancer cells and macrophages through periostin promotes macrophage recruitment

Tumor‐associated macrophages (TAMs) contribute to tumor progression, but it is not clear how they are recruited to tumor sites. Here we showed that periostin (POSTN) was present at high levels in ovarian cancer ascetic fluids and was correlated with CD163⁺ TAMs. The high POSTN level and macrophage infiltration were inversely associated with relapse‐free survival for ovarian cancer patients. In vitro studies showed that coculture with macrophages significantly increased POSTN production in ovarian cancer cells. Further investigation found that POSTN production in ovarian cancer cells was promoted by transforming growth factor‐β generated by macrophages. Moreover, siRNA of POSTN and POSTN neutralizing antibody treatment showed that ovarian cancer cell‐derived POSTN promoted the recruitment of macrophages and modulated their cytokine secretion profile. Collectively, these data indicated that POSTN was an important factor for macrophage recruitment in the tumor microenvironment and is involved in the interactions between macrophages and ovarian cancer cells.     

Tumor‐associated macrophages exhibit pro‐ and anti‐inflammatory properties by which they impact on pancreatic tumorigenesis

Pancreatic ductal adenocarcinoma (PDAC) still ranking 4th in the order of fatal tumor diseases is characterized by a profound tumor stroma with high numbers of tumor‐associated macrophages (TAMs). Driven by environmental factors, monocytes differentiate into M1‐ or M2‐macrophages, the latter commonly regarded as being protumorigenic. Because a detailed analysis of TAMs in human PDAC development is still lacking, freshly isolated PDAC‐derived TAMs were analyzed for their phenotype and impact on epithelial‐mesenchymal‐transition (EMT) of benign (H6c7) and malignant (Colo357) pancreatic ductal epithelial cells. TAMs exhibited characteristics of M1‐macrophages (expression of HLA‐DR, IL‐1β, or TNF‐α) and M2‐macrophages (expression of CD163 and IL‐10). In the presence of TAMs, H6c7, and Colo357 cells showed an elongated cell shape along with an increased expression of mesenchymal markers such as vimentin and reduced expression of epithelial E‐cadherin. Similar to TAMs, in vitro generated M1‐ and M2‐macrophages both mediated EMT in H6c7 and Colo357 cells. M1‐macrophages acquired M2‐characteristics during coculture that could be prevented by GM‐CSF treatment. However, M1‐macrophages still potently induced EMT in H6c7 and Colo357 cells although lacking M2‐characteristics. Overall, these data demonstrate that TAMs exhibit anti‐ as well as proinflammatory properties that equally contribute to EMT induction in PDAC initiation and development.     

Tumor associated macrophage expressing CD204 is associated with tumor aggressiveness of esophageal squamous cell carcinoma

Tumor associated macrophages (TAMs) are the most abundant cancer stromal cells educated by tumor microenvironment to acquire trophic functions facilitating angiogenesis, matrix breakdown and cancer cell motility. Tumor associated macrophages have anti‐inflammatory properties or “alternatively” activated (M2) phenotype expressing CD204 and/or CD163. To know the role of TAMs in the growth and progression of esophageal squamous cell carcinomas (ESCCs), we calculated intratumoral CD204, CD163 or CD68 expressing macrophage count (M?C) and CD34‐positive microvessel density (MVD) by immunohistochemistry in 70 cases of surgically resected ESCCs and compared them with the clinicopathological factors and prognosis of patients. M?C had positive linear association with MVD. High CD204⁺ M?C were significantly correlated with more malignant phenotypes including depth of tumor invasion, lymph and blood vessel invasion, lymph node metastasis as well as clinical stages. On the other hand, CD163⁺ M?C did not associate with these clinicopathological factors with the exception of depth of tumor invasion and blood vessel invasion. Patients with high CD204⁺ M?C ESCCs showed poor disease‐free survival (P = 0.021). Conditioned media of five ESCC cell lines (TE‐8, ‐9, ‐10, ‐11 and ‐15) induced mRNA as well as protein expression of CD204 but not of CD163 with upregulation of vascular endothelial growth factor‐A mRNA in TPA treated human acute monocytic leukemia cell line THP‐1. These results overall indicate that CD204 is a useful marker for TAMs contributing to the angiogenesis, progression and prognosis of ESCCs whose specific tumor microenvironment may educate macrophages to be CD204⁺ M2 TAMs.     

Anti‐inflammatory M2 type macrophages characterize metastasized and tyrosine kinase inhibitor‐treated gastrointestinal stromal tumors

We have made a detailed inventory of the immune infiltrate of gastrointestinal stromal tumors (GISTs), which originate from mesenchymal cells in the intestinal tract. These sarcomas are heavily infiltrated with macrophages and T cells, while immune cells of other lineages were much less abundant. Dissecting the functional subtypes of T cells with multicolor fluorescent microscopy revealed substantial populations of cytotoxic T cells, helper T cells and FoxP3⁺ regulatory T cells. The balance of cytotoxic T cells and FoxP3⁺ T cells was toward immune suppression. Analysis of the macrophage population also showed a dominance of anti‐inflammatory cells, as the M2 type scavenger receptor CD163 was abundantly present. Other subsets of macrophages (CD14⁺CD163⁻) were occasionally detected. M2 type CD163⁺ macrophages were associated with the number of infiltrating FoxP3⁺ regulatory T cells and twice as many macrophages were found in metastatic GIST compared to primary lesions. Most metastatic GISTs had been treated with the tyrosine kinase inhibitors imatinib and sunitinib, but the high macrophage infiltrate was not related to this treatment. However, imatinib and sunitinib did induce secretion of anti‐inflammatory IL‐10 in macrophage cultures, indicating that treatment with these inhibitors might contribute to an immune suppressive microenvironment in GIST. Overall, our data reveal a picture of GIST as an active site of tumor‐immune interaction in which suppressive mechanisms overrule potential antitumor responses. Tyrosine kinase inhibitors might promote this negative balance.     

Human breast cancer cells educate macrophages toward the M2 activation status

Introduction

The immune system plays a major role in cancer progression. In solid tumors, 5-40 % of the tumor mass consists of tumor-associated macrophages (TAMs) and there is usually a correlation between the number of TAMs and poor prognosis, depending on the tumor type. TAMs usually resemble M2 macrophages. Unlike M1-macrophages which have pro-inflammatory and anti-cancer functions, M2-macrophages are immunosuppressive, contribute to the matrix-remodeling, and hence favor tumor growth. The role of TAMs is not fully understood in breast cancer progression.

Methods

Macrophage infiltration (CD68) and activation status (HLA-DRIIα, CD163) were evaluated in a large cohort of human primary breast tumors (562 tissue microarray samples), by immunohistochemistry and scored by automated image analysis algorithms. Survival between groups was compared using the Kaplan-Meier life-table method and a Cox multivariate proportional hazards model. Macrophage education by breast cancer cells was assessed by ex vivo differentiation of peripheral blood mononuclear cells (PBMCs) in the presence or absence of breast cancer cell conditioned media (MDA-MB231, MCF-7 or T47D cell lines) and M1 or M2 inducing cytokines (respectively IFN-γ, IL-4 and IL-10). Obtained macrophages were analyzed by flow cytometry (CD14, CD16, CD64, CD86, CD200R and CD163), ELISA (IL-6, IL-8, IL-10, monocyte colony stimulating factor M-CSF) and zymography (matrix metalloproteinase 9, MMP-9).

Results

Clinically, we found that high numbers of CD163⁺ M2-macrophages were strongly associated with fast proliferation, poor differentiation, estrogen receptor negativity and histological ductal type (p<0.001) in the studied cohort of human primary breast tumors. We demonstrated ex vivo that breast cancer cell-secreted factors modulate macrophage differentiation toward the M2 phenotype. Furthermore, the more aggressive mesenchymal-like cell line MDA-MB231, which secretes high levels of M-CSF, skews macrophages toward the more immunosuppressive M2c subtype.

Conclusions

This study demonstrates that human breast cancer cells influence macrophage differentiation and that TAM differentiation status correlates with recurrence free survival, thus further emphasizing that TAMs can similarly affect therapy efficacy and patient outcome.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-015-0621-0) contains supplementary material, which is available to authorized users.     

Modulatory effects of adiponectin on the polarization of tumor‐associated macrophages

The plasticity of macrophages with selective functional phenotypes partially arises in respective to their microenvironment. Tumor‐associated macrophages (TAMs) may promote disease progression with tumor specific manner. Here we report that in pediatric malignant soft‐tissue tumors, the presence of TAMs and expression of adiponectin (APN) are heterogeneous. Both APN and TAMs had high expression in rhabdomyosarcoma, especially in the malignant subtype, alveolar rhabdomyosarcoma. To investigate the mode of action of APN on TAM activation, a murine MN/MCA1 sarcoma model was used. The Results revealed that exogenous APN had no effect on MN/MCA1 proliferation but tumor size was markedly reduced in apn^?/? mice versus WT controls. The accumulation of TAMs in apn^?/? mice was also reduced which correlated to downregulated serum levels of MCP‐1. Likewise, TAMs in apn^?/? mice exhibited a M1‐like phenotype, characterized by increase in MHC II^high population and M1 phenotypic markers, such as iNOS gene and serum TNF‐α accompanied by a decrease in M2 markers, namely YM1 gene and serum IL‐10. In addition, APN deficiency increased the number of CD4⁺ T cells, CD8⁺ T cells and NK cells in tumors and reduced tumor metastasis. The altered phenotype of TAMs in apn^?/? mice was associated with a marked decrease in phospho‐p38 and treatment with a p38 MAPK inhibitor significantly reduced tumor size and increased MHC II expression on TAMs in WT mice, implying p38 MAPK signaling pathway may contribute to APN‐mediated TAM polarization. Collectively, our findings suggest that APN may have a potential role in regulating soft tissue sarcoma growth.     

Tumor‐infiltrating M2 macrophage in pretreatment biopsy sample predicts response to chemotherapy and survival in esophageal cancer

The association between the tumor microenvironment (TME) and treatment response or survival has been a recent focus in several types of cancer. However, most study materials are resected specimens that were completely modified by prior chemotherapy; therefore, the unmodified host immune condition has not yet been clarified. The aim of the present study was to evaluate the relationship between TME assessed in pre–therapeutic biopsy samples and chemoresistance in esophageal cancer (EC). A total of 86 endoscopic biopsy samples from EC patients who received neoadjuvant chemotherapy (NAC) prior to surgery were evaluated for the number of intratumoral CD4⁺ lymphocytes (with/without Foxp3 expression), CD8⁺ lymphocytes (with/without PD‐1 expression), monocytes (CD14⁺) and macrophages (CD86⁺, CD163⁺ and CD206⁺) by multiplex immunohistochemistry (IHC). The number of tumor‐infiltrating CD206⁺ macrophages I significantly correlated with cT, cM, cStage and neutrophil/lymphocyte ratio (NLR), whereas the number of lymphocytes (including expression of Foxp3 and PD‐1) was not associated with clinico‐pathological features. The high infiltration of CD163⁺ or CD206⁺ macrophages was significantly associated with poor pathological response to NAC (P = 0.0057 and 0.0196, respectively). Expression of arginase‐1 in CD163⁺ macrophages tended to be higher in non–responders (29.4% vs 18.2%, P = 0.17). In addition, patients with high infiltration of M2 macrophages exhibited unfavorable overall survival compared to those without high infiltration of M2 macrophages (5‐year overall survival 57.2% vs 71.0%, P = 0.0498). Thus, a comprehensive analysis of TME using multiplex IHC revealed that M2 macrophage infiltration would be useful in predicting the response to NAC and long‐term survival in EC patients.     

鼻咽NK/T细胞淋巴瘤肿瘤相关巨噬细胞与其增殖活性的关系

目的：研究鼻咽NK/T细胞淋巴瘤中肿瘤相关巨噬细胞（TAMs）数量与肿瘤增殖指数,以及2种巨噬细胞标志物（CD68与CD163）间的关系。方法：采用免疫组织化学染色法检测31例鼻咽NK/T细胞淋巴瘤和12例炎性反应病例的Ki67,CD68以及CD163。并对染色结果进行Pearson相关分析和t检验。结果：鼻咽NK/T细胞淋巴瘤中的TAMs数与肿瘤的增殖活性具有非常显著的正相关性（P=0.024）,同时,CD163与CD68阳性细胞数密切相关（P=0.009）,CD68的阳性率略高于CD163,但无统计学意义。鼻咽NK/T细胞淋巴瘤中TAMs的数量,与反应性病变相比具有明显差异（P〈0.05）。结论：鼻咽NK/T细胞淋巴瘤中的TAMs与肿瘤细胞增殖活性密切相关,表明TAMs可促进NK/T细胞淋巴瘤细胞的增殖。并且2种标志物（CD68及CD163）均可识别TAMs。而CD163为TAMs的标志物似乎更加准确。     

Immunotherapy of B‐cell non‐Hodgkin lymphoma by targeting the chemokine receptor CXCR5 in a preclinical mouse model

Bispecific antibodies are promising agents for immunotherapy. Here, we describe a quadroma‐based trifunctional bispecific antibody binding the chemokine receptor CXCR5 and the T‐cell antigen CD3 that efficiently prevents tumor growth in a mouse B‐cell lymphoma model. CXCR5 regulates the tissue homeostasis of mature B cells and is highly expressed on B‐cell non‐Hodgkin and lymphocyte‐predominant Hodgkin lymphoma, as well as on a subset of CD4⁺ T cells known as follicular T‐helper cells. In vitro, the bispecific CXCR5::CD3 antibody efficiently recruited effector T cells to CXCR5 expressing B cells and induced a co‐stimulation‐independent activation of CD8⁺ and CD4⁺ T cells as demonstrated by the de novo expression of CD25 and CD69, and secretion of the cytokines IFN‐γ, TNF‐α, IL‐6 and IL‐10 by peripheral blood mononuclear cells. Notably, at low antibody concentrations, CXCR5::CD3 displayed a significantly higher cytotoxic activity against autologous B cells than its parental antibodies or rituximab. In vivo imaging revealed that CXCR5::CD3 and its parental CXCR5 antibody efficiently prevent tumor growth in a xenograft model of B‐cell lymphoma in mice and prolong their survival. Taken together, our results identify CXCR5 as a promising target for antibody‐based therapies in the treatment of B‐cell malignancies.     

Mixed‐polarization phenotype of ascites‐associated macrophages in human ovarian carcinoma: Correlation of CD163 expression,cytokine levels and early relapse

Ovarian cancer is typically accompanied by the occurrence of malignant ascites containing large number of macrophages. It has been suggested that these tumor‐associated macrophages (TAMs) are skewed to alternative polarization (M2) and thereby play an essential role in therapy resistance and metastatic spread. In our study, we have investigated the nature, regulation and clinical correlations of TAM polarization in serous ovarian cancer. Macrophage polarization markers on TAMs and ascites cytokine levels were analyzed for 30 patients and associated with relapse‐free survival (RFS) in a prospective study with 20 evaluable patients. Surface expression of the M2 marker CD163 on TAMs was inversely associated with RFS (p < 0.01). However, global gene expression profiles determined for 17 of these patients revealed a mixed‐polarization phenotype unrelated to the M1/M2 classification. CD163 surface expression also correlated with the ascites levels of IL‐6 and IL‐10 (p < 0.05), both cytokines induced CD163 expression, and their ascites levels showed a clear inverse association with RFS (p < 0.01). These findings define a subgroup of patients with high CD163 expression, high IL‐6 and/or IL‐10 levels and poor clinical outcome.     

Crosstalk between colon cancer cells and macrophages via inflammatory mediators and CD47 promotes tumour cell migration

Tumour-associated macrophages (TAMs) of the M2 phenotype are present in the stroma of many tumours and are frequently associated with the progression of several types of cancer. We investigated the role of M2 macrophages in colon cancer progression and found that human colon cancer tissue had elevated numbers of CD68⁺ (macrophage marker) cells and CD206⁺ (M2 macrophage marker) cells and increased CD47 expression. To explore potential interplay between colon cancer cells and M2 macrophages, we differentiated the monocyte cell line THP-1 into M1 and M2 macrophages (CD206^high and Th2 cytokine-secreting cells), respectively. M2 macrophages migrated faster than M1 macrophages towards SW480-conditioned medium. Similarly, M2 macrophage-conditioned medium induced SW480 cell migration and CD47 expression. Factors released by macrophages were involved in this induction. In addition, SW480 cells migrated faster when co-cultured with M2 macrophages. Inhibition of CD47 with blocking antibodies or siRNA significantly reduced the migration of SW480 cells in the presence of M2 macrophages. This effect was further decreased via blocking antibodies against the CD47 ligand signal-regulatory protein α (SIRPα). Additionally, cancer cells also secreted significant levels of IL-10, thereby promoting M2 macrophage differentiation. These findings indicate that a TAM-enriched tumour microenvironment promotes colon cancer cell migration and metastasis.     

Infiltration of tumor‐associated macrophages is involved in tumor programmed death‐ligand 1 expression in early lung adenocarcinoma

Programmed death‐ligand 1 (PD‐L1) is an immune modulator that promotes immunosuppression by binding to programmed death‐1 of T‐lymphocytes. Although tumor cell PD‐L1 expression has been shown to be associated with the clinical response to anti–PD‐L1 antibodies, its concise regulatory mechanisms remain elusive. In this study, we evaluated the associations of tumor PD‐L1 expression and immune cell infiltrating patterns in 146 cases of early lung adenocarcinoma (AC) to investigate the possible extrinsic regulation of tumor PD‐L1 by immune cells. Using immunohistochemistry, cell surface PD‐L1 expression in tumor cells was observed in 18.5% of stage 0‐IA lung AC patients. Tumor PD‐L1 positivity was significantly associated with stromal invasion, which was accompanied by increased tumor‐associated macrophages (TAM), CD8⁺ cytotoxic T cells and FoxP3⁺ regulatory T cells. Among these immune cells, TAM and CD8⁺ T cells significantly accumulated in PD‐L1‐positive carcinoma cell areas, which showed a tumor cell nest‐infiltrating pattern. Although CD8⁺ T cells are known to induce tumor PD‐L1 expression via interferon‐? production, the increased TAM within tumors were also associated with tumor cell PD‐L1 positivity, independently of CD8⁺ T cell infiltration. Our in vitro experiments revealed that PD‐L1 expression in lung cancer cell lines was significantly upregulated by co–culture with M2‐differentiated macrophages; expression of PD‐L1 was reduced to baseline levels following treatment with a transforming growth factor‐β inhibitor. These results demonstrated that tumor‐infiltrating TAM are extrinsic regulators of tumor PD‐L1 expression, indicating that combination therapy targeting both tumor PD‐L1 and stromal TAM might be a possible strategy for effective treatment of lung cancer.     

Prognostic significance of CD169‐positive lymph node sinus macrophages in patients with endometrial carcinoma

Lymph node (LN) macrophages play critical roles in anti‐tumor immunity, which develops via the activation of cytotoxic T cells (CTL) and NK cells. The present study aims to determine the prognostic significance of CD169⁺ LN macrophages in patients with endometrial carcinoma (EC). The number of CD169⁺ cells or the CD169⁺‐to‐CD68⁺ macrophage ratio in regional LN (RLN), and the number of CD8⁺ CTL or CD57⁺ NK cells in tumor tissues were investigated by immunohistochemistry in paraffin‐embedded tissue samples from 79 patients with EC. A high density of CD169⁺ cells in the RLN of patients with EC was correlated with an early clinical stage or no LN metastasis. A high number of CD169⁺ cells and a high CD169⁺‐to‐CD68⁺ macrophage ratio were significantly associated with longer overall survival in EC. We also found that the density of CD169⁺ macrophages was positively correlated with the number of CD8⁺ CTL and CD57⁺ NK cells that infiltrated into tumor tissues. A high density of CD57⁺ cells in EC tissues was associated with a better prognosis, while a high density of CD8⁺ cells was not linked to an altered prognosis. The present study showed that the density of CD169⁺ macrophages in RLN was associated with an improved prognosis in EC patients. CD169⁺ macrophages in RLN might represent a useful marker for assessing clinical prognoses and monitoring anti‐tumor immunity in patients with EC.     

Impact of tumor‐associated macrophages on invasive ductal carcinoma of the pancreas head

Tumor‐associated macrophages (TAMs) are candidate histological factors in invasive ductal carcinoma (IDC) of the pancreas. Tumor‐associated macrophages can be affected by cancer‐related inflammation and pancreatitis and interact with important invasive behavior in a recurrent manner in pancreatic IDC. These features may help elucidate the aggressiveness of pancreatic IDC. The aim of this study was to characterize TAMs in pancreatic IDC in comparison with chronic pancreatitis (CP) and to reveal TAM‐related factors and the clinical impact of TAMs. CD68 (a pan‐macrophage marker) and CD204 (an M2 macrophage marker) immunohistochemistry was carried out in pancreas head specimens from 107 IDC cases and 11 CP cases. Immunopositive cell areas were calculated at the periphery and center of the tumor. The distributions of macrophages in IDC and CP and the relationship between TAMs and histological tumor factors, survival, and recurrence were evaluated. Macrophages were more frequently observed in the lesion periphery than the center in IDC and CP. The density of macrophages was elevated in IDC compared to CP. Dense M2 macrophages at the tumor periphery were frequently seen in large tumors and showed an independent impact on overall survival and disease‐free time. Early recurrence in the liver or the local manipulated area was associated with high accumulation of peripheral M2 macrophages. More M2 macrophages were seen in IDC than in CP in both the periphery and the center. High numbers of peripheral M2 macrophages were associated with large tumor size, early recurrence in the liver, local recurrence, and shortened survival time in patients with pancreatic IDC. (Cancer Sci, doi: 10.1111/j.1349‐7006.2012.02411.x, 2012)     

Tumor-associated macrophages of the M2 phenotype contribute to progression in gastric cancer with peritoneal dissemination

Background

Tumor-associated macrophages (TAMs) of the M2 phenotype are known to promote tumor proliferation and to be associated with a poor prognosis in numerous cancers. Here, we investigated whether M2 macrophages participate in the development of peritoneal dissemination in gastric cancer.

Methods

The characteristics of peritoneal macrophages in gastric cancer patients with or without peritoneal dissemination were examined by flow cytometry and the real-time quantitative polymerase chain reaction. The effects of M2 macrophages on phenotypic changes of the gastric cancer cell line MKN45 were assessed with a direct or indirect co-culture system in vitro and an in vivo mouse xenograft model.

Results

The number of peritoneal macrophages with the M2 phenotype (CD68⁺CD163⁺ or CD68⁺CD204⁺) was significantly higher in gastric cancer patients with peritoneal dissemination than in those without peritoneal dissemination. Higher expression of the M2-related messenger RNAs (IL-10, vascular endothelial growth factor A, vascular endothelial growth factor C, matrix metalloproteinase 1, and amphiregulin) and lower expression of M1-related messenger RNAs (TNF-α, CD80, CD86, and IL-12p40) were also confirmed in the TAMs. Macrophage co-culture with gastric cancer cells converted M1 phenotype into M2 phenotype. Moreover, the coexistence of MKN45 cells with M2 macrophages resulted in cancer cell proliferation and an acceleration of tumor growth in the xenograft model.

Conclusions

Intraperitoneal TAMs in gastric cancer patients with peritoneal dissemination were polarized to the M2 phenotype, and could contribute to tumor proliferation and progression. Therefore, intraperitoneal TAMs are expected to be a promising target in the treatment of peritoneal dissemination in gastric cancer.

     

Omental Macrophagic “Crown-like Structures” Are Associated with Poor Prognosis in Advanced-Stage Serous Ovarian Cancer

The tumor microenvironment is a well-recognized framework in which immune cells present in the tumor microenvironment promote or inhibit cancer formation and development. A crown-like structure (CLS) has been reported as a dying or dead adipocyte surrounded by a ‘crown’ of macrophages within adipose tissue, which is a histologic hallmark of the inflammatory process in this tissue. CLSs have also been found to be related to formation, progression and prognosis of some types of cancer. However, the presence of CLSs in the omentum of advanced-stage high-grade serous ovarian carcinoma (HGSOC) has not been thoroughly investigated. By using CD68, a pan-macrophage marker, and CD163, an M2-like polarization macrophage marker, immunohistochemistry (IHC) was performed to identify tumor-associated macrophages (TAMs) and CLSs. This retrospective study analyzed 116 patients with advanced-stage HGSOC who received complete treatment and had available clinical data from July 2008 through December 2016 at National Cheng Kung University Hospital (NCKUH) (Tainan, Taiwan). Based on multivariate Cox regression analysis, patients with omental CD68⁺ CLSs had poor OS (median survival: 24 vs. 38 months, p = 0.001, hazard ratio (HR): 2.26, 95% confidence interval (CI): 1.41–3.61); patients with omental CD163⁺ CLSs also had poor OS (median survival: 22 vs. 36 months, HR: 2.14, 95%CI: 1.33–3.44, p = 0.002). Additionally, patients with omental CD68⁺ or CD163⁺ CLSs showed poor PFS (median survival: 11 vs. 15 months, HR: 2.28, 95%CI: 1.43–3.64, p = 0.001; median survival: 11 vs. 15 months, HR: 2.17, 95%CI: 1.35–3.47, respectively, p = 0.001). Conversely, the density of CD68⁺ or CD163⁺ TAMs in ovarian tumors was not associated with patient prognosis in advanced-stage HGSOC in our cohort. In conclusion, we, for the first time, demonstrate that the presence of omental CLSs is associated with poor prognosis in advanced-stage HGSOC.     

Targeting high‐grade B cell lymphoma with CD19‐specific T cells

Adoptive T cell therapy is an important additional treatment option for malignant diseases resistant to chemotherapy. Using a murine high‐grade B cell lymphoma model, we have addressed the question whether the B cell differentiation antigen CD19 can act as rejection antigen. CD19^?/? mice inoculated with CD19⁺ B cell lymphoma cells showed higher survival rates than WT mice and were protected against additional tumor challenge. T cell depletion prior to tumor transfer completely abolished the protective response. By heterotypic vaccination of CD19^?/? mice against murine CD19, survival after tumor challenge was significantly increased. To define protective epitopes within the CD19 molecule, T cells collected from mice that had survived the tumor transfer were analyzed for IFNγ secretion in response to CD19‐derived peptides. The majority of mice exhibited a CD4⁺ T cell response to CD19 peptide 27, which was the most dominant epitope after CD19 vaccination. A peptide 27‐specific CD4⁺ T cell line protected CD19^?/? mice against challenge with CD19⁺ lymphoma and also cured a significant proportion of WT mice from recurrent disease in a model of minimal residual disease after chemotherapy. In conclusion, our data highlight CD19‐specific CD4⁺ T cells for adoptive T cell therapy of B cell lymphomas.