AIRE is expressed in breast cancer TANs and TAMs to regulate the extrinsic apoptotic pathway and inflammation.

The autoimmune regulator (AIRE) is a transcriptional regulator expressed in the thymus and is necessary for maintaining immunological self-tolerance. Extrathymic AIRE expression is rare, and a role for AIRE in tumor-associated innate immune cells has not yet been established. In this study, we show that AIRE is expressed in human pro-tumor neutrophils. In breast cancer, AIRE was primarily located to tumor-associated neutrophils (TANs), and to a lesser extent to tumor-associated macrophages (TAMs) and tumor cells. Expression of AIRE in TAN/TAMs, but not in cancer cells, was associated with an adverse prognosis. We show that the functional role for AIRE in neutrophils and macrophages is to regulate expression of immune mediators and the extrinsic apoptotic pathway involving the Fas/TNFR death receptors and cathepsin G. Here, we propose that the role for AIRE in TAN/TAMs in breast tumors is to regulate cell death and inflammation, thus promoting tumor progression.

Breast cancer associated CD169+ macrophages possess broad immunosuppressive functions but enhance antibody secretion by activated B cells.

CD169+ resident macrophages in lymph nodes of breast cancer patients are for unknown reasons associated with a beneficial prognosis. This contrasts CD169+ macrophages present in primary breast tumors (CD169+ TAMs), that correlate with a worse prognosis. We recently showed that these CD169+ TAMs were associated with tertiary lymphoid structures (TLSs) and Tregs in breast cancer. Here, we show that CD169+ TAMs can be monocyte-derived and express a unique mediator profile characterized by type I IFNs, CXCL10, PGE2 and inhibitory co-receptor expression pattern. The CD169+ monocyte-derived macrophages (CD169+ Mo-M) possessed an immunosuppressive function in vitro inhibiting NK, T and B cell proliferation, but enhanced antibody and IL6 secretion in activated B cells. Our findings indicate that CD169+ Mo-M in the primary breast tumor microenvironment are linked to both immunosuppression and TLS functions, with implications for future targeted Mo-M therapy.

Spatial immunophenotyping of the tumour microenvironment in non-small cell lung cancer.

INTRODUCTION: Immune cells in the tumour microenvironment are associated with prognosis and response to therapy. We aimed to comprehensively characterise the spatial immune phenotypes in the mutational and clinicopathological background of non-small cell lung cancer (NSCLC). METHODS: We established a multiplexed fluorescence imaging pipeline to spatially quantify 13 immune cell subsets in 359 NSCLC cases: CD4 effector cells (CD4-Eff), CD4 regulatory cells (CD4-Treg), CD8 effector cells (CD8-Eff), CD8 regulatory cells (CD8-Treg), B-cells, natural killer cells, natural killer T-cells, M1 macrophages (M1), CD163+ myeloid cells (CD163), M2 macrophages (M2), immature dendritic cells (iDCs), mature dendritic cells (mDCs) and plasmacytoid dendritic cells (pDCs). RESULTS: CD4-Eff cells, CD8-Eff cells and M1 macrophages were the most abundant immune cells invading the tumour cell compartment and indicated a patient group with a favourable prognosis in the cluster analysis. Likewise, single densities of lymphocytic subsets (CD4-Eff, CD4-Treg, CD8-Treg, B-cells and pDCs) were independently associated with longer survival. However, when these immune cells were located close to CD8-Treg cells, the favourable impact was attenuated. In the multivariable Cox regression model, including cell densities and distances, the densities of M1 and CD163 cells and distances between cells (CD8-Treg-B-cells, CD8-Eff-cancer cells and B-cells-CD4-Treg) demonstrated positive prognostic impact, whereas short M2-M1 distances were prognostically unfavourable. CONCLUSION: We present a unique spatial profile of the in situ immune cell landscape in NSCLC as a publicly available data set. Cell densities and cell distances contribute independently to prognostic information on clinical outcomes, suggesting that spatial information is crucial for diagnostic use.

CD169+ Macrophages in Primary Breast Tumors Associate with Tertiary Lymphoid Structures, Tregs and a Worse Prognosis for Patients with Advanced Breast Cancer.

The presence of CD169+ macrophages in the draining lymph nodes of cancer patients is, for unknown reasons, associated with a beneficial prognosis. We here investigated the prognostic impact of tumor-infiltrating CD169+ macrophages in primary tumors (PTs) and their spatial relation to tumor-infiltrating B and T cells. Using two breast cancer patient cohorts, we show that CD169+ macrophages were spatially associated with the presence of B and T cell tertiary lymphoid-like structures (TLLSs) in both PTs and lymph node metastases (LNMs). While co-infiltration of CD169+/TLLS in PTs correlated with a worse prognosis, the opposite was found when present in LNMs. RNA sequencing of breast tumors further confirmed that SIGLEC1 (CD169) expression was associated with mature tertiary lymphoid structure (TLS), and Treg and Breg signatures. We propose that the negative prognostic value related to CD169+ macrophages in PTs is a consequence of an immunosuppressive tumor environment rich in TLSs, Tregs and Bregs.

An immune score reflecting pro- and anti-tumoural balance of tumour microenvironment has major prognostic impact and predicts immunotherapy response in solid cancers.

BACKGROUND: Cancer immunity is based on the interaction of a multitude of cells in the spatial context of the tumour tissue. Clinically relevant immune signatures are therefore anticipated to fundamentally improve the accuracy in predicting disease progression. METHODS: Through a multiplex in situ analysis we evaluated 15 immune cell classes in 1481 tumour samples. Single-cell and bulk RNAseq data sets were used for functional analysis and validation of prognostic and predictive associations. FINDINGS: By combining the prognostic information of anti-tumoural CD8+ lymphocytes and tumour supportive CD68+CD163+ macrophages in colorectal cancer we generated a signature of immune activation (SIA). The prognostic impact of SIA was independent of conventional parameters and comparable with the state-of-art immune score. The SIA was also associated with patient survival in oesophageal adenocarcinoma, bladder cancer, lung adenocarcinoma and melanoma, but not in endometrial, ovarian and squamous cell lung carcinoma. We identified CD68+CD163+ macrophages as the major producers of complement C1q, which could serve as a surrogate marker of this macrophage subset. Consequently, the RNA-based version of SIA (ratio of CD8A to C1QA) was predictive for survival in independent RNAseq data sets from these six cancer types. Finally, the CD8A/C1QA mRNA ratio was also predictive for the response to checkpoint inhibitor therapy. INTERPRETATION: Our findings extend current concepts to procure prognostic information from the tumour immune microenvironment and provide an immune activation signature with high clinical potential in common human cancer types. FUNDING: Swedish Cancer Society, Lions Cancer Foundation, Selanders Foundation, P.O. Zetterling Foundation, U-CAN supported by SRA CancerUU, Uppsala University and Region Uppsala.

The injury-induced transcription factor SOX9 alters the expression of LBR, HMGA2, and HIPK3 in the human kidney.

Induction of SRY box transcription factor 9 (SOX9) has been shown to occur in response to kidney injury in rodents, where SOX9-positive cells proliferate and regenerate the proximal tubules of injured kidneys. Additionally, SOX9-positive cells demonstrate a capacity to differentiate toward other nephron segments. Here, we characterized the role of SOX9 in normal and injured human kidneys. SOX9 expression was found to colocalize with a proportion of so-called scattered tubular cells in the uninjured kidney, a cell population previously shown to be involved in kidney injury and regeneration. Following injury and in areas adjacent to inflammatory cell infiltrates, SOX9-positive cells were increased in number. With the use of primary tubular epithelial cells (PTECs) obtained from human kidney tissue, SOX9 expression was spontaneously induced in culture and further increased by transforming growth factor-ß1, whereas it was suppressed by interferon-γ. siRNA-mediated knockdown of SOX9 in PTECs followed by analysis of differential gene expression, immunohistochemical expression, and luciferase promoter assays suggested lamin B receptor (LBR), high mobility group AT-hook 2 (HMGA2), and homeodomain interacting protein kinase 3 (HIPK3) as possible target genes of SOX9. Moreover, a kidney explant model was used to demonstrate that only SOX9-positive cells survive the massive injury associated with kidney ischemia and that the surviving SOX9-positive cells spread and repopulate the tubules. Using a wound healing assay, we also showed that SOX9 positively regulated the migratory capacity of PTECs. These findings shed light on the functional and regulatory aspects of SOX9 activation in the human kidney during injury and regeneration.NEW & NOTEWORTHY Recent studies using murine models have shown that SRY box transcription factor 9 (SOX9) is activated during repair of renal tubular cells. In this study, we showed that SOX9-positive cells represent a proportion of scattered tubular cells found in the uninjured human kidney. Furthermore, we suggest that expression of LBR, HMGA2, and HIPK3 is altered by SOX9 in the kidney tubular epithelium, suggesting the involvement of these gene products in kidney injury and regeneration.

High Infiltration of CD68+/CD163- Macrophages Is an Adverse Prognostic Factor after Neoadjuvant Chemotherapy in Esophageal and Gastric Adenocarcinoma.

Tumor-associated macrophages (TAMs) have emerged as key players in tumor immunology but demonstrate a continuum of functional states being either tumor suppressive or promoting. Moreover, chemotherapeutic agents have been shown to alter the tumor microenvironment. Perioperative chemotherapy is a standard treatment option for resectable esophageal and gastric (EG) adenocarcinoma. The aim of this study was to investigate the influence of neoadjuvant chemotherapy (NAC) on TAMs to improve the prognostication and treatment course for these patients. The study cohort comprised 148 patients, all of whom were diagnosed with resectable EG adenocarcinoma and treated with NAC. Immunohistochemistry was applied to assess the total infiltration and infiltration into tumor nests (TN) of CD68+/CD163-, CD68+/CD163+, and MARCO+ TAMs, on paired biopsies from primary tumors (PT) pre-NAC, and resected PT and lymph node metastases post-NAC. In pre-NAC specimens, high CD68+/CD163+ infiltration into TN was an unfavorable prognostic factor. No association was found between TAM density in PT pre-NAC and histopathological regression. The density of CD68+/CD163+ TAMs was increased in PT post-NAC, while the density of MARCO+ TAMs was decreased. CD68+/CD163- TAM density was not altered. In post-NAC specimens, higher total as well as TN infiltration of CD68+/CD163- TAMs were adverse prognostic factors. In conclusion, these results suggest that NAC may alter certain TAM subsets in EG adenocarcinoma, along with their functional properties and thus their prognostic value.

Peripheral Blood Mononuclear Cell Populations Correlate with Outcome in Patients with Metastatic Breast Cancer.

Local tumor-associated immune cells hold prognostic and predictive value in various forms of malignancy. The role of systemic, circulating leukocytes is, however, not well-characterized. In this prospective and explorative study, we aim to delineate the clinical relevance of a broad panel of circulating immune cells in 32 patients with newly diagnosed metastatic breast cancer (MBC) before the start of systemic treatment. Freshly isolated peripheral blood mononuclear cells (PBMCs) were analyzed by flow cytometry and evaluated for potential associations to clinicopathological variables and patient outcome. We show that the levels of specific circulating leukocyte populations are associated with clinical parameters such as hormone receptor status, histological subtype, number of circulating tumor cells (CTCs) and metastatic burden. Importantly, high levels of CD8+ cytotoxic T lymphocytes (CTLs) are significantly linked to improved overall survival (OS). In patients with estrogen receptor (ER)-positive primary tumors, high levels of circulating CTLs and non-classical (CD14+CD16++) monocytes were associated with improved OS, whereas in patients with ER-negative tumors low levels of circulating natural killer (NK) cells potentially associate with improved OS. We propose that the levels of specific circulating immune cell populations, such as CD8+ CTLs, may be used to predict clinical outcomes in MBC patients. Thus, larger studies are warranted to validate these findings.

Branching Copy-Number Evolution and Parallel Immune Profiles across the Regional Tumor Space of Resected Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) remains a highly lethal disease. The only option for curative treatment is resection of the tumor followed by standard adjuvant chemotherapy. Yet, early relapse due to chemoresistance is almost inevitable. Herein, we delineated the genetic intratumor heterogeneity in resected PDAC, with the aim to identify evolutionary patterns that may be associated with overall survival (OS) following treatment with curative intent. Potential relationships with the adjacent immune microenvironment were also examined. The genetic and immune landscapes of the regional tumor space were analyzed in nine patients with resected PDAC. Targeted deep sequencing and genome wide SNP array were followed by clonal deconvolution and phylogenetic analysis. A mathematical complexity score was developed to calculate the network extent of each phylogeny. Spatial variation in abundancy and tumor nest infiltration of immune cells was analyzed by double IHC staining. Copy-number heterogeneity was denoted as the major contributing factor to the branching architectures of the produced phylogenetic trees. Increased tree complexity was significantly inversely associated with OS, and larger regional maximum aberrations (higher treetops) were associated with increased PD-L1 expression on tumor cells. Contrastingly, an FREM1 gene amplification, found in one patient, coincided with a particularly vigorous immune response. Findings from this limited case series suggest that complex evolutionary patterns may be associated with a shorter survival in surgically treated patients with PDAC. Some hypothesis-generating associations with the surrounding immune microenvironment were also detected. IMPLICATIONS: Evolutionary copy-number patterns may be associated with survival in patients with resected PDAC.

The Immune Landscape of Colorectal Cancer.

While the clinical importance of CD8+ and CD3+ cells in colorectal cancer (CRC) is well established, the impact of other immune cell subsets is less well described. We sought to provide a detailed overview of the immune landscape of CRC in the largest study to date in terms of patient numbers and in situ analyzed immune cell types. Tissue microarrays from 536 patients were stained using multiplexed immunofluorescence panels, and fifteen immune cell subclasses, representing adaptive and innate immunity, were analyzed. Overall, therapy-naïve CRC patients clustered into an 'inflamed' and a 'desert' group. Most T cell subsets and M2 macrophages were enriched in the right colon (p-values 0.046-0.004), while pDC cells were in the rectum (p = 0.008). Elderly patients had higher infiltration of M2 macrophages (p = 0.024). CD8+ cells were linked to improved survival in colon cancer stages I-III (q = 0.014), while CD4+ cells had the strongest impact on overall survival in metastatic CRC (q = 0.031). Finally, we demonstrated repopulation of the immune infiltrate in rectal tumors post radiation, following an initial radiation-induced depletion. This study provides a detailed analysis of the in situ immune landscape of CRC paving the way for better diagnostics and providing hints to better target the immune microenvironment.

Infiltration of NK and plasma cells is associated with a distinct immune subset in non-small cell lung cancer.

Immune cells of the tumor microenvironment are central but erratic targets for immunotherapy. The aim of this study was to characterize novel patterns of immune cell infiltration in non-small cell lung cancer (NSCLC) in relation to its molecular and clinicopathologic characteristics. Lymphocytes (CD3+, CD4+, CD8+, CD20+, FOXP3+, CD45RO+), macrophages (CD163+), plasma cells (CD138+), NK cells (NKp46+), PD1+, and PD-L1+ were annotated on a tissue microarray including 357 NSCLC cases. Somatic mutations were analyzed by targeted sequencing for 82 genes and a tumor mutational load score was estimated. Transcriptomic immune patterns were established in 197 patients based on RNA sequencing data. The immune cell infiltration was variable and showed only poor association with specific mutations. The previously defined immune phenotypic patterns, desert, inflamed, and immune excluded, comprised 30, 13, and 57% of cases, respectively. Notably, mRNA immune activation and high estimated tumor mutational load were unique only for the inflamed pattern. However, in the unsupervised cluster analysis, including all immune cell markers, these conceptual patterns were only weakly reproduced. Instead, four immune classes were identified: (1) high immune cell infiltration, (2) high immune cell infiltration with abundance of CD20+ B cells, (3) low immune cell infiltration, and (4) a phenotype with an imprint of plasma cells and NK cells. This latter class was linked to better survival despite exhibiting low expression of immune response-related genes (e.g. CXCL9, GZMB, INFG, CTLA4). This compartment-specific immune cell analysis in the context of the molecular and clinical background of NSCLC reveals two previously unrecognized immune classes. A refined immune classification, including traits of the humoral and innate immune response, is important to define the immunogenic potency of NSCLC in the era of immunotherapy. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

T cells, B cells, and PD-L1 expression in esophageal and gastric adenocarcinoma before and after neoadjuvant chemotherapy: relationship with histopathological response and survival.

Perioperative chemotherapy enhances the survival rates for patients with esophageal and gastric (EG) adenocarcinoma, but not all patients benefit from this additional treatment. Chemotherapeutic agents have been demonstrated to alter the immune cell (IC) composition in the tumor microenvironment. Hence, there is a rationale to investigate the influence of neoadjuvant chemotherapy (NAC) on different IC subsets, to better understand and compare their utility as complementary prognostic or predictive biomarkers in a clinically relevant context. The density of T cells (CD8+ and FoxP3+), B cells (CD20+) and the expression of PD-L1 on ICs and tumor cells (TC) was assessed by immunohistochemistry on paired biopsies from primary tumors (PT) pre-NAC, and resected PT and lymph node metastases post-NAC. The cohort encompasses 148 patients with resectable EG adenocarcinoma, all of whom received NAC. The density of CD8+ cells was decreased and the density of FoxP3+ cells and CD20+ cells was increased in PT post-NAC. PD-L1 expression was not altered following NAC. In pre-NAC specimens, high FoxP3+ density and high PD-L1 expression on ICs were favorable prognostic factors, whereas high CD8+ density was an unfavorable prognostic factor. In post-NAC specimens, however, high FoxP3+ density was an unfavorable prognostic factor, and high PD-L1 expression on TC was associated with a shorter survival. There were no significant associations between IC density or PD-L1 expression in PT pre-NAC and histopathological regression. These findings propose that NAC might alter the density and prognostic impact of some IC subsets in EG adenocarcinoma.

Co-localization of CD169+ macrophages and cancer cells in lymph node metastases of breast cancer patients is linked to improved prognosis and PDL1 expression.

Breast cancer is the most common form of cancer in women worldwide. Although the survival among breast cancer patients has improved, there is still a large group of patients with dismal prognosis. One of the most important prognostic factors for poor prognosis is lymph node metastasis. Increasing knowledge concerning the lymph nodes of breast cancer patients indicates that they are affected by the primary tumor. In this study we show that presence of CD169+ subcapsular sinus macrophages in contact with lymph node metastases in breast cancer patients, is related to better prognosis after adjuvant tamoxifen treatment, but only in patients with PDL1+ primary tumors. This is in contrast to the prognostic effect of CD169+ primary tumor-associated macrophages (TAMs). We further show that CD169+ macrophages were spatially associated with expression of PDL1 on nearby cells, both in primary tumors and metastatic lymph node, although PDL1 expression in metastatic lymph node as such did not have further prognostic impact. Our data suggest that CD169+ resident lymph node macrophages have a unique function in targeting immune responses against breast cancer and should be further investigated in detail.

Tumor-Associated CD68+, CD163+, and MARCO+ Macrophages as Prognostic Biomarkers in Patients With Treatment-Naïve Gastroesophageal Adenocarcinoma.

Background: Despite improvements in surgical methodologies and perioperative chemo- and radiotherapy, the prognosis for patients with esophageal and gastric cancer remains poor. Hence, there is a great need to identify complementary biomarkers for improved treatment stratification. Tumor-infiltrating immune cells have been shown to impact on outcome in many types of cancer, including gastroesophageal cancer. The aim of this present study was to examine the prognostic value of tumor-infiltrating macrophages in gastroesophageal adenocarcinoma. Methods: The density of CD68+, CD163+, and MARCO+ macrophages was assessed by immunohistochemistry on tissue microarrays with primary tumors from a consecutive, retrospective cohort of 174 patients with treatment-naïve gastroesophageal adenocarcinoma. Total densities and infiltration in tumor nest (TN) were denoted as none/sparse (0), intermediate (1), or high (2). The impact on overall survival (OS) was examined by Kaplan-Meier analysis, log-rank test, and Cox proportional hazards modeling. Results: Increased infiltration of both CD68+ and CD163+, but not MARCO+, macrophages in TN was significantly associated with a stepwise reduced survival. Median OS for patients with none/sparse, intermediate, and high CD68+ TN infiltration was 4.4, 2.6, and 1.0 years, respectively. Median OS for patients with none/sparse, intermediate, and high CD163+ TN infiltration was 4.4, 2.2, and 1.1 years, respectively. High infiltration of CD68+ macrophages remained an independent prognostic factor in adjusted analysis (hazard ratio = 1.61, 95% confidence interval = 1.02-2.55, and p = 0.041). Conclusion: Infiltration of CD68+ and CD163+, but not MARCO+, macrophages is prognostic for OS in gastroesophageal adenocarcinoma. The relevance of this finding in clinical practice remains to be elucidated.

Topographical Distribution and Spatial Interactions of Innate and Semi-Innate Immune Cells in Pancreatic and Other Periampullary Adenocarcinoma.

Background: The clinical management of pancreatic and other periampullary neoplasms remains challenging. In contrast to other cancer types, immunotherapies are largely ineffective, and the reason for the deprived immune response and the immune inhibiting cellular composition is only fragmentarily understood. The aim of this study was to comprehensively map the abundance, topographic distribution and spatial interaction of innate and innate-like immune cells in the tumor microenvironment of periampullary adenocarcinoma. Methods: Multiplexed immunofluorescent imaging was performed on tissue microarrays with tumors from a consecutive cohort of 175 patients with resected periampullary adenocarcinoma. To obtain a detailed spatial analysis of immune cell infiltration, two multiplex immune panels including antibodies against CD3, NKp46, CD56, CD68, CD163 and CD1a, CD208, CD123, CD15, CD68 and pan-cytokeratin were applied. Results: The infiltration of natural killer (NK) and NK-like T (NKT) cells was lower in malignant compared to benign tissue. NKT cells were more abundant in intestinal type compared to pancreatobiliary type tumors, and were associated with more favorable clinicopathological features and a prolonged survival. The interaction of NKp46+ NKT cells with macrophages was also associated with a prolonged survival. Conclusions: This study provides a comprehensive map of the innate immune landscape in periampullary adenocarcinoma. NK cells, and even more so NKT cells, are revealed to be central players in the local immune response in a clinically relevant context.

Human G-MDSCs are neutrophils at distinct maturation stages promoting tumor growth in breast cancer.

Myeloid-derived suppressor cells (MDSCs) are known to contribute to immune evasion in cancer. However, the function of the human granulocytic (G)-MDSC subset during tumor progression is largely unknown, and there are no established markers for their identification in human tumor specimens. Using gene expression profiling, mass cytometry, and tumor microarrays, we here demonstrate that human G-MDSCs occur as neutrophils at distinct maturation stages, with a disease-specific profile. G-MDSCs derived from patients with metastatic breast cancer and malignant melanoma display a unique immature neutrophil profile, that is more similar to healthy donor neutrophils than to G-MDSCs from sepsis patients. Finally, we show that primary G-MDSCs from metastatic breast cancer patients co-transplanted with breast cancer cells, promote tumor growth, and affect vessel formation, leading to myeloid immune cell exclusion. Our findings reveal a role for human G-MDSC in tumor progression and have clinical implications also for targeted immunotherapy.

Complement inhibitor factor H expressed by breast cancer cells differentiates CD14+ human monocytes into immunosuppressive macrophages.

Macrophages are a major immune cell type in the tumor microenvironment, where they display a tumor-supporting phenotype. Factor H (FH) is a complement inhibitor that also plays a role in several cellular functions. To date, the phenotype of monocytes stimulated with FH has been unexplored. We discovered that FH is a survival factor for CD14+ primary human monocytes, promoting their differentiation into macrophages in serum-free medium. This activity was localized to the C-terminal domains of FH and it was inhibited in plasma, indicating that the phenomenon may be most relevant in tissues. FH-induced macrophages display characteristics of immunosuppressive cells including expression of CD163 and CD206, release of the anti-inflammatory cytokine IL-10 and changes in metabolism. Furthermore, FH-induced macrophages express low levels of HLA-DR but high levels of co-inhibitory molecule programmed death-ligand 1 (PD-L1), and accordingly, a reduced capacity for T-cell activation. Finally, we show that FH is expressed by human breast cancer cells and that this correlates with the presence of immunosuppressive macrophages, breast cancer recurrence and severity of the disease. We propose that the expression of FH by tumor cells and the promotion of an immunosuppressive cancer microenvironment by this protein should be taken into account when considering the effectiveness of immunotherapies against breast cancer.

Deletion of Nemo-like Kinase in T Cells Reduces Single-Positive CD8+ Thymocyte Population.

The ß-catenin/Wnt signaling pathway plays an important role in all stages of T cell development. Nemo-like kinase (NLK) is an evolutionary conserved serine/threonine kinase and a negative regulator of the Wnt signaling pathway. NLK can directly phosphorylate histone deacetylase 1 (HDAC1), as well as T cell factor/lymphoid enhancer-binding factor (TCF/LEF), causing subsequent repression of target gene transcription. By engineering mice lacking NLK in early stages of T cell development, we set out to characterize the role NLK plays in T cell development and found that deletion of NLK does not affect mouse health or lymphoid tissue development. Instead, these mice harbored a reduced number of single-positive (SP) CD8+ thymocytes without any defects in the SP CD4+ thymocyte population. The decrease in SP CD8+ thymocytes was not caused by a block in differentiation from double-positive CD4+CD8+ cells. Neither TCR signaling nor activation was altered in the absence of NLK. Instead, we observed a significant increase in cell death and reduced phosphorylation of LEF1 as well as HDAC1 among NLK-deleted SP CD8+ cells. Thus, NLK seems to play an important role in the survival of CD8+ thymocytes. Our data provide evidence for a new function for NLK with regard to its involvement in T cell development and supporting survival of SP CD8+ thymocytes.

Prognostic implications of the expression levels of different immunoglobulin heavy chain-encoding RNAs in early breast cancer.

The extent and composition of the immune response in a breast cancer is one important prognostic factor for the disease. The aim of the current work was to refine the analysis of the humoral component of an immune response in breast tumors by quantifying mRNA expression of different immunoglobulin classes and study their association with prognosis. We used RNA-Seq data from two local population-based breast cancer cohorts to determine the expression of IGJ and immunoglobulin heavy (IGH) chain-encoding RNAs. The association with prognosis was investigated and public data sets were used to corroborate the findings. Except for IGHE and IGHD, mRNAs encoding heavy chains were generally detected at substantial levels and correlated with other immune-related genes. High IGHG1 mRNA was associated with factors related to poor prognosis such as estrogen receptor negativity, HER2 amplification, and high grade, whereas high IGHA2 mRNA levels were primarily associated with lower age at diagnosis. High IGHA2 and IGJ mRNA levels were associated with a more favorable prognosis both in univariable and multivariable Cox models. When adjusting for other prognostic factors, high IGHG1 mRNA levels were positively associated with improved prognosis. To our knowledge, these results are the first to demonstrate that expression of individual Ig class types has prognostic implications in breast cancer.

Chemotherapy, host response and molecular dynamics in periampullary cancer: the CHAMP study.

BACKGROUND: Pancreatic cancer is a devastating disease with a dismal prognosis. Despite profound medical advances in systemic therapies for other types of aggressive tumours during recent years, a diagnosis of pancreatic cancer is still often synonymous with a fatal outcome. The term periampullary cancer includes pancreatic cancer and applies to the group of tumours found in proximity to the ampulla of Vater. Molecular events and immune response in the host during chemotherapy remain largely unexplored in this group of tumours. Therefore, the "Chemotherapy, Host Response and Molecular Dynamics in Periampullary Cancer (CHAMP)" study aims to monitor these processes to gain new insight into this perplexing disease. METHODS: The CHAMP study is a prospective, single-arm observational study. All patients diagnosed with pancreatic or other periampullary adenocarcinoma undergoing adjuvant or palliative chemotherapy treatment in the Department of Oncology, Skåne University Hospital, are invited to participate. Clinical and pathological data will be compiled at study entry. A single tissue microarray (TMA) block is constructed for each patient with a resected tumour and blood samples are drawn before, during and after chemotherapy in order to sample peripheral blood mononuclear cells (PBMC), cytokines and circulating tumour DNA (ctDNA). Next generation sequencing will be performed on tumour tissue and ctDNA to detect changes in the clonal landscape over space and time. DISCUSSION: Despite the recent emergence of some promising biomarkers for periampullary cancer, there has been a lack of success in clinical implementation. Cancer cells continuously adapt and become resistant to treatment during chemotherapy. To be able to keep pace with and hopefully overtake this rapid evolution we must, with the help of new diagnostic tools, be ready to adapt and alter treatment accordingly. It seems to us that the only way forward is to gain a better understanding of the dynamics of the disease during treatment. With insights gained from the CHAMP study we hope to find answers to key questions in this largely unexplored territory. TRIAL REGISTRATION: This study has been registered 30th October 2018 at clinicaltrials.gov as NCT03724994.