Infiltrating dendritic/Langerhans cells in primary breast cancer

Matrix stiffness enhances cancer-macrophage interactions and M2-like macrophage accumulation in the breast tumor microenvironment

The role of intratumor heterogeneity is becoming increasingly apparent in part due to expansion in single cell technologies. Clinically, tumor heterogeneity poses several obstacles to effective cancer therapy dealing with biomarker variability and treatment responses. Matrix stiffening is known to occur during tumor progression and contribute to pathogenesis in several cancer hallmarks, including tumor angiogenesis and metastasis. However, the effects of matrix stiffening on intratumor heterogeneity have not been thoroughly studied. In this study, we applied single-cell RNA sequencing to investigate the differences in the transcriptional landscapes between stiff and compliant MMTV-PyMT mouse mammary tumors. We found similar compositions of cancer and stromal subpopulations in compliant and stiff tumors but differential intercellular communication and a significantly higher concentration of tumor-promoting, M2-like macrophages in the stiffer tumor microenvironments. Interestingly, we found that cancer cells seeded on stiffer substrates recruited more macrophages. Furthermore, elevated matrix stiffness increased Colony Stimulating Factor 1 (CSF-1) expression in breast cancer cells and reduction of CSF-1 expression on stiffer substrates reduced macrophage recruitment. Thus, our results demonstrate that tissue phenotypes were conserved between stiff and compliant tumors but matrix stiffening altered cell-cell interactions which may be responsible for shifting the phenotypic balance of macrophages residing in the tumor microenvironment towards a pro-tumor progression M2 phenotype. STATEMENT OF SIGNIFICANCE: Cells within tumors are highly heterogeneous, posing challenges with treatment and recurrence. While increased tissue stiffness can promote several hallmarks of cancer, its effects on tumor heterogeneity are unclear. We used single-cell RNA sequencing to investigate the differences in the transcriptional landscapes between stiff and compliant MMTV-PyMT mouse mammary tumors. We found similar compositions of cancer and stromal subpopulations in compliant and stiff tumors but differential intercellular communication and a significantly higher concentration of tumor-promoting, M2-like macrophages in the stiffer tumor microenvironments. Using a biomaterial-based platform, we found that cancer cells seeded on stiffer substrates recruited more macrophages, supporting our in vivo findings. Together, our results demonstrate a key role of matrix stiffness in affecting cell-cell communication and macrophage recruitment.

Phenotypes and Functions of Human Dendritic Cell Subsets in the Tumor Microenvironment

Dendritic cells (DCs) play a key role in the antitumor immunity, as they are at the interface of innate and adaptive immunity. This important task can only be performed thanks to the broad range of mechanisms that DCs can perform to activate other immune cells. As DCs are well known for their outstanding capacity to prime and activate T cells through antigen presentation, DCs were intensively investigated during the past decades. Numerous studies have identified new DC subsets, leading to a large variety of subsets commonly separated into cDC1, cDC2, pDCs, mature DCs, Langerhans cells, monocyte-derived DCs, Axl-DCs, and several other subsets. Here, we review the specific phenotypes, functions, and localization within the tumor microenvironment (TME) of human DC subsets thanks to flow cytometry and immunofluorescence but also with the help of high-output technologies such as single-cell RNA sequencing and imaging mass cytometry (IMC).

Immunological profiles of the breast cancer microenvironment represented by tumor-infiltrating lymphocytes and PD-L1 expression

Tumor-infiltrating lymphocytes (TILs) and programmed cell death 1 ligand 1 (PD-L1) are established prognostic and predictive biomarkers for certain breast cancer subsets. However, their association with the immune response complexity is not fully understood. Therefore, we analyzed the association between the immune cell fractions in breast cancer tissues and histologically assessed TIL (hTIL) and PD-L1 (hPD-L1). Forty-five tumor and eighteen blood samples were collected from patients with breast cancer. Total leukocyte counts, frequency of 11 immune cell populations, and PD-L1 expression in each cell fraction were evaluated by flow cytometry. TILs and PD-L1 were assessed by hematoxylin and eosin staining and immunohistochemistry, respectively. A higher hTIL score showed association with increased leukocyte infiltration, higher CD4⁺ and CD8⁺ T cell proportions, and lower natural killer and natural killer T cell proportions. PD-L1 was highly expressed in nonclassical monocytes, monocyte/macrophages, myeloid-derived suppressor cells, myeloid dendritic cells, dendritic cells, and other lineages in tumors. hPD-L1 positivity reflected PD-L1 expression accurately in these fractions, as well as increased leukocyte infiltration in tumors. These results indicate that hTILs reflect differences in the immune responses in the tumor microenvironment, and certain immune cell fractions are favorably expressed in the PD-L1 pathway in breast cancer microenvironments.

Novel Concepts: Langerhans Cells in the Tumour Microenvironment

Langerhans cells (LCs) are immune cells that reside in the stratified epithelium of the skin and mucosal membranes. They play a range of roles in the skin, including antigen presentation and maintenance of peripheral tolerance. Reports of LC numbers have been variable in different cancer types, with the majority of studies indicating a reduction in their number. Changes in the cytokine profile and other secreted molecules, downregulation of surface molecules on cells and hypoxia all contribute to the regulation of LCs in the tumour microenvironment. Functionally, LCs have been reported to regulate immunity and carcinogenesis in different cancer types. An improved understanding of the function and biology of LCs in tumours is essential knowledge that underpins the development of new cancer immunotherapies.

Diagnostic utility of CD205 in breast cancer: Simultaneous detection of myoepithelial cells and dendritic cells in breast tissue by CD205

BACKGROUND

CD205 can be used to detect myoepithelial cells (MECs) and dendritic cells (DCs) in breast tissue. However, the usefulness of CD205 immunostaining in the pathological diagnosis of breast tumors is not fully understood. The objective of this study was to re-evaluate CD205 co-expression with other MEC markers, such as p63 and CD10, in nonneoplastic and neoplastic breast tissue and to evaluate its pathological diagnostic utility in these types of breast cancer.

MATERIAL AND METHODS

Nonneoplastic breast tissue samples with a terminal duct lobular unit and duct were obtained from fibroadenoma and mastopathy patients. Neoplastic breast tissue samples included ductal carcinoma in situ (DCIS) (n=43) and invasive ductal carcinoma (IDC) (n=60), including the tubule-forming type (n=20). These specimens were investigated by CD205, p63, and CD10 immunostaining.

RESULTS

In addition to p63 and CD10, CD205 was expressed on MECs in nonneoplastic breast and DCIS tissue samples; CD205 was simultaneously detected on DCs that had infiltrated DCIS and IDC tumor nests. CD205 was expressed on cancer cells themselves in only 7.3% of the breast cancer samples. The number of intratumoral CD205⁺ DCs in tubular IDC was significantly higher than that in DCIS (P<0.01).

CONCLUSION

Because CD205 was simultaneously detected on MECs and DCs in the same breast tissue sections, it may be useful for distinguishing tubular IDC from DCIS.

Human Tumor-Infiltrating Dendritic Cells: From in Situ Visualization to High-Dimensional Analyses

The interaction between tumor cells and the immune system is considered to be a dynamic process. Dendritic cells (DCs) play a pivotal role in anti-tumor immunity owing to their outstanding T cell activation ability. Their functions and activities are broad ranged, triggering different mechanisms and responses to the DC subset. Several studies identified in situ human tumor-infiltrating DCs by immunostaining using a limited number of markers. However, considering the heterogeneity of DC subsets, the identification of each subtype present in the immune infiltrate is essential. To achieve this, studies initially relied on flow cytometry analyses to provide a precise characterization of tumor-associated DC subsets based on a combination of multiple markers. The concomitant development of advanced technologies, such as mass cytometry or complete transcriptome sequencing of a cell population or at a single cell level, has provided further details on previously identified populations, has unveiled previously unknown populations, and has finally led to the standardization of the DCs classification across tissues and species. Here, we review the evolution of tumor-associated DC description, from in situ visualization to their characterization with high-dimensional technologies, and the clinical use of these findings specifically focusing on the prognostic impact of DCs in cancers.

Role of Chemokines in Thyroid Cancer Microenvironment: Is CXCL8 the Main Player?

Tumor-related inflammation does influence the biological behavior of neoplastic cells and ultimately the patient's outcome. With specific regard to thyroid cancer, the issue of tumor-associated inflammation has been extensively studied and recently reviewed. However, the role of chemokines, which play a crucial role in determining the immuno-phenotype of tumor-related inflammation, was not addressed in previous reviews on the topic. Experimental evidence shows that thyroid cancer cells actively secrete a wide spectrum of chemokines and, at least for some of them, solid scientific data support a role for these immune-active molecules in the aggressive behavior of the tumor. Our proposal for a review article on chemokines and thyroid cancer stems from the notion that chemokines, besides having the ability to attract and maintain immune cells at the tumor site, also produce several pro-tumorigenic actions, which include proangiogenetic, cytoproliferative, and pro-metastatic effects. Studies taking into account the role of CCL15, C-X-C motif ligand 12, CXCL16, CXCL1, CCL20, and CCL2 in the context of thyroid cancer will be reviewed with particular emphasis on CXCL8. The reason for focusing on CXCL8 is that this chemokine is the most studied one in human malignancies, displaying multifaceted pro-tumorigenic effects. These include enhancement of tumor cells growth, metastatization, and angiogenesis overall contributing to the progression of several cancers including thyroid cancer. We aim at reviewing current knowledge on the (i) ability of both normal and tumor thyroid cells to secrete CXCL8; (ii) direct/indirect pro-tumorigenic effects of CXCL8 demonstrated by in vitro and in vivo studies specifically performed on thyroid cancer cells; and (iii) pharmacologic strategies proven to be effective for lowering CXCL8 secretion and/or its effects on thyroid cancer cells.

Herbal preparation (HemoHIM) enhanced functional maturation of bone marrow-derived dendritic cells mediated toll-like receptor 4

Background

HemoHIM, which is an herbal preparation of three edible herbs (Angelicam gigas Nakai, Cnidium offinale Makino, and Peaonia japonica Miyabe), is known to have various biological and immunological activities, but the modulatory effects of this preparation on dendritic cells (DCs)-mediated immune responses have not been examined previously. DCs are a unique group of white blood cells that initiate primary immune responses by capturing, processing, and presenting antigens to T cells.

Results

In the present study, we investigated the effect of HemoHIM on the functional and phenotypic maturation of murine bone marrow-derived dendritic cells (BMDCs) both in vitro and in vivo. The expression of co-stimulatory molecules (CD40, CD80, CD86, MHC I, and MHC II) and the production of cytokines (IL-1β, IL-6, IL-12p70, and TNF-α) were increased by HemoHIM in BMDCs. Furthermore, the antigen-uptake ability of BMDCs was decreased by HemoHIM, and the antigen-presenting ability of HemoHIM-treated mature BMDCs increased TLR4-dependent CD4⁺ and CD8⁺ T cell responses.

Conclusions

Our findings demonstrated that HemoHIM induces TLR4-mediated BMDCs functional and phenotypic maturation through in vivo and in vitro. And our study showed the antigen-presenting ability that HemoHIM-treated mature BMDCs increase CD4⁺ and CD8⁺ T cell responses by in vitro. These results suggest that HemoHIM has the potential to mediate DC immune responses.

Breast cancer stem cells phenotype and plasma cell-predominant breast cancer independently indicate poor survival

PURPOSE

Cancer stem cell-tumor microenvironment ecosystem is proposed to drive tumor heterogeneity. Tumor-infiltrating lymphocytes (TILs) in breast cancer ecosystem were demonstrated to indicate better prognosis and benefit from chemotherapy. This study sought to detect the association between breast cancer stem cells and TILs.

METHODS

92 patients with breast cancer were enrolled. Matched cancerous and paracancerous tissues were assembled in a tissue microarray and immunohistochemistry was employed to test expression of breast cancer stem cells (BCSCs) markers. TILs counts were estimated with global hematoxylin-eosin staining. The association between TILs and BCSCs phenotypes was analysed by multivariate analysis.

RESULTS

Although it was unable to find direct significant association between BCSCs phenotypes and TILs, the BCSCs phenotype with CD44(+)CD24(-)ALDH1A1(+)EpCAM(+)CD49f(+) was proved to be associated with worse DFS and OS (P=0.037 and 0.001). This result was confirmed by cox proportional-hazards regression model (for DFS and OS respectively, HR=2.438 and 3.383, P=0.019 [95%CI 1.418-3.457] and 0.025 [95%CI 1.162-9.843]). Additionally, in results of TILs, plasma cell-predominant breast cancer (PPBC) was unexpectedly found to indicate worse OS and HR was 2.686 (P=0.038 [95%CI 1.582-3.789]).

CONCLUSIONS

The BCSCs phenotype and PPBC may be helpful stratified factors in future clinical trials. The underlying mechanism needs further research.

CD1a-positive dendritic cell density predicts disease-free survival in papillary thyroid carcinoma

OBJECTIVES

Dendritic cells are common in inflammatory processes and in papillary thyroid carcinoma (PTC). Previous studies of the predictive value of S100-positive dendritic cell density for PTC outcome yielded inconsistent results. This study investigated the association of dendritic cell density and PTC recurrence based on CD1a expression.

METHODS

Representative slides from 56 consecutive specimens of PTC were immunostained with anti-CD1a antibodies, and dendritic cell density was analyzed by disease-free survival.

RESULTS

Dendritic cells were abundant in the tumoral tissue and sparse in the normal peritumoral tissue. Peritumoral dendritic cell density >1.1 cells/HPF was inversely associated with the risk of recurrence. Similar results were obtained with tumoral dendritic cell density (>12 cells/HPF), although the statistical significance was marginal.

CONCLUSIONS

High CD1a-positive dendritic cell density is associated with improved disease-free survival in PTC. The specificity of anti-CD1a immunostain for activated dendritic cells may explain the better outcome prediction in this study than in studies using S100 protein.

Dendritic cell vaccines for leukemia patients

Dendritic cells are the most professional antigen-presenting cells to elicit T-cellular responses toward microbial agents and cancer cells. The graft-versus-leukemia effect observed after allogeneic stem cell transplantation strongly suggests that T lymphocytes play a major role in the rejection of leukemic cells. This graft-versus-leukemia effect might be enhanced through dendritic cell vaccination. The characterization of leukemia-specific antigens eliciting immune responses in the autologous host has prompted researchers and clinicians to broaden the spectrum of dendritic cell vaccines to hematological malignancies. Recently, the focus is on acute myeloid leukemia and chronic lymphocytic leukemia. This review summarizes data on the administration of autologous and allogeneic dendritic cells to leukemia patients as an interesting approach in cellular therapy of leukemias.

Spatial organization of dendritic cells within tumor draining lymph nodes impacts clinical outcome in breast cancer patients

BACKGROUND

Dendritic cells (DCs) are important mediators of anti-tumor immune responses. We hypothesized that an in-depth analysis of dendritic cells and their spatial relationships to each other as well as to other immune cells within tumor draining lymph nodes (TDLNs) could provide a better understanding of immune function and dysregulation in cancer.

METHODS

We analyzed immune cells within TDLNs from 59 breast cancer patients with at least 5 years of clinical follow-up using immunohistochemical staining with a novel quantitative image analysis system. We developed algorithms to analyze spatial distribution patterns of immune cells in cancer versus healthy intra-mammary lymph nodes (HLNs) to derive information about possible mechanisms underlying immune-dysregulation in breast cancer. We used the non-parametric Mann-Whitney test for inter-group comparisons, Wilcoxon Matched-Pairs Signed Ranks test for intra-group comparisons and log-rank (Mantel-Cox) test for Kaplan Maier analyses.

RESULTS

Degree of clustering of DCs (in terms of spatial proximity of the cells to each other) was reduced in TDLNs compared to HLNs. While there were more numerous DC clusters in TDLNs compared to HLNs,DC clusters within TDLNs tended to have fewer member DCs and also consisted of fewer cells displaying the DC maturity marker CD83. The average number of T cells within a standardized radius of a clustered DC was increased compared to that of an unclustered DC, suggesting that DC clustering was associated with T cell interaction. Furthermore, the number of T cells within the radius of a clustered DC was reduced in tumor-positive TDLNs compared to HLNs. Importantly, clinical outcome analysis revealed that DC clustering in tumor-positive TDLNs correlated with the duration of disease-free survival in breast cancer patients.

CONCLUSIONS

These findings are the first to describe the spatial organization of DCs within TDLNs and their association with survival outcome. In addition, we characterized specific changes in number, size, maturity, and T cell co-localization of such clusters. Strategies to enhance DC function in-vivo, including maturation and clustering, may provide additional tools for developing more efficacious DC cancer vaccines.

Regulation of epithelial cell turnover and macrophage phenotype by epithelial cell-derived transforming growth factor beta1 in the mammary gland

Transforming growth factor beta1 (TGFB1) is a multi-functional cytokine that regulates cell proliferation, apoptosis and immune system responses. In the breast, the mammary epithelium is the primary source of TGFB1 and increased expression is associated with increased breast cancer risk. This study was conducted to investigate the roles of epithelial cell-derived TGFB1 in regulation of epithelial cell activity and macrophage phenotype in the mammary gland. Tgfb1 null mutant and wildtype mammary epithelium was transplanted into contra-lateral sides of the cleared mammary gland of TGFB1 replete scid mice. Transplanted tissue was analysed for markers of proliferation and apoptosis to determine the effect of Tgfb1 null mutation on epithelial cell turnover, and was analysed by immunohistochemistry to investigate the location, abundance and phenotype of macrophages. The number of proliferating and dying ductal epithelial cells, determined by BrdU and TUNEL, was increased by 35% and 3.3-fold respectively in mammary gland transplanted with Tgfb1 null epithelium compared to wildtype epithelium (p<0.05). Abundance of F4/80+ macrophages in between Tgfb1 null epithelial cells compared to wildtype epithelial cells was increased by 50%. The number of iNOS+ and CCR7+ cells in the stroma surrounding Tgfb1 null alveolar epithelium was increased by 78% and 2-fold respectively, and dendriform MHC class II+ cells within ductal epithelium were decreased by 30%. We conclude that epithelial cell-derived TGFB1 in the mammary gland has two functions: (1) regulation of cellular turnover of epithelial cells, and (2) regulation of local macrophage phenotype. These findings shed new light on the diversity of roles of TGFB1 in the mammary gland which are likely to impact on breast cancer risk.

Deciphering the message broadcast by tumor-infiltrating dendritic cells

Human dendritic cells (DCs) infiltrate solid tumors, but this infiltration occurs in favorable and unfavorable disease prognoses. The statistical inference is that tumor-infiltrating DCs (TIDCs) play no conclusive role in predicting disease progression. This is remarkable because DCs are highly specialized antigen-presenting cells linking innate and adaptive immunity. DCs either boost the immune system (enhancing immunity) or dampen it (leading to tolerance). This dual effect explains the dual outcomes of cancer progression. The reverse functional characteristics of DCs depend on their maturation status. This review elaborates on the markers used to detect DCs in tumors. In many cases, the identification of DCs in human cancers relies on staining for S-100 and CD1a. These two markers are mainly expressed by Langerhans cells, which are one of several functionally different DC subsets. The activation status of DCs is based on the expression of CD83, DC-SIGN, and DC-LAMP, which are nonspecific markers of DC maturation. The detection of TIDCs has not kept pace with the increased knowledge about the identification of DC subsets and their maturation status. Therefore, it is difficult to draw a conclusion about the performance of DCs in tumors. We suggest a novel selection of markers to distinguish human DC subsets and maturation states. The use of these biomarkers will be of pivotal importance to scrutinize the prognostic significance of TIDCs.

Clinical significance of langerhans cells in squamous cell carcinoma of the larynx

Langerhans cells (LCs) may be involved in the immunosurveillance against tumors as antigen-presenting cells. Our objective has been to determine the relevance of LC in progression of larynx squamous cell carcinomas and their relationship with different subpopulations of tumor-infiltrating cells. LCs were investigated by immunohistochemical methods using anti-CD1 antibody. LCs were detected in most of the primary tumors studied (44 out of 50) and also in metastases (6 out of 10) and recurrences (2 out of 3), but we did not find any statistical association between number of LCs and clinical-pathological parameters or survival. However, the number of LCs was increased in patients with evident infiltration of lymphocytes, mainly cytotoxic T cells. We can conclude that although LCs did not show clinical utility as prognostic marker, they may play a role in releasing an active immune response in larynx carcinomas, according to their ability to present antigens to sensitized T cells.

Aqueous extract of Phyllanthus niruri (Euphorbiaceae) enhances the phenotypic and functional maturation of bone marrow-derived dendritic cells and their antigen-presentation function

Decoctions of Phyllanthus niruri (PN) (Fam. Euphorbiaceae) is promoted in traditional medicine of Africa, Asia, and South America as beneficial supplement for different infectious diseases, especially for viral hepatitis, tumor, and for immune compromised patients. This stimulated the interest in understanding the mechanisms by which the whole extract of the plant could stimulate the immune system. Dendritic cells (DCs) are professional antigen-presenting cells and provide a link between the innate and the adaptive immune responses. In the present study, the effects of lyophilized aqueous extract of PN on structural and functional maturation of murine bone marrow-derived DCs (BM-DCs) were investigated. Bone marrow cells were cultured in the presence of granulocyte macrophage-colony stimulating factor and interleukin-4 (IL-4) and the generated immature DCs were stimulated with PN (25, 50, and 100 microg/mL) or lipopolysaccharide (10 microg/mL) for 48 h. Results showed that treatment with PN increased the expression of major histocompatibility complex-II and the various makers for DCs maturation (CD40), activation (CD83), and costimulation (CD86) in a concentration-dependent manner. Consistent with the increase in phenotypic makers, functional maturation assay showed that treatment of BM-DCs with PN caused a decrease in fluorescein isothiocyanate-dextran pinocytosis and an increase in IL-12 in the supernatant. In a transgenic T-cell activation model, PN-treated BM-DCs presented Ova antigen to Ova-specific CD8(+) T cells from OT-1 mice more efficiently as demonstrated by increased T-cells proliferation and IL-2 production. Therefore, PN enhances the structural and functional maturation of BM-DCs and their antigen-presenting function. These effects are relevant in immunodeficient conditions, tumor control, and in infectious diseases.

Prognostic significance of CD83, CD1a and Ki-67 expression in colorectal carcinoma

AIM: To analyze the prognostic significance of CD83, CD1a, and Ki-67 expression in colorectal carcinoma.

METHODS: The expression of CD83, CD1a, and Ki-67 in 60 cases of colorectal cancer was detected by immunohistochemistry and flow cytometry (FCM). The correlations of CD83, CD1a, and Ki-67 expression with clinicopathological parameters and prognosis in colorectal cancer were analyzed.

RESULTS: Immunohistochemistry analysis showed that the positive rates of CD83 and CD1a in early-stage (Dukes' stage) colorectal cancer patients and those with a good prognosis were significantly higher than those in advanced-stage patients and those with a poor prognosis, respectively (all P < 0.05). FCM analysis showed that the positive rate of CD1a was significantly higher in early-stage colorectal cancer patients and those with a good prognosis than in advanced-stage patients and those with a poor prognosis, respectively (both P < 0.05). Both immunohistochemistry and FCM results showed that the positive rate of Ki-67 was significantly lower in early-stage colorectal cancer patients and those with a good prognosis than in advanced-stage patients and those with a poor prognosis, respectively (both P < 0.05).

CONCLUSION: CD83, CD1a, and Ki-67 expression is correlated with the Dukes' stage and prognosis of colorectal cancer and can therefore be used as a prognostic parameter for the disease.

Role of tumor-derived proinflammatory cytokines GM-CSF, TNF-alpha, and IL-12 in the migration and differentiation of antigen-presenting cells in cervical carcinoma

BACKGROUND

Proinflammatory cytokines are important in modifying the activity, differentiation, and migration of antigen-presenting cells and may influence the survival of cancer patients. The study assessed whether GM-CSF, TNF-alpha, and IL-12, produced by cervical cancer cells, are important for the activity, differentiation, and migration of antigen-presenting cells.

METHODS

In 90 patients with cervical carcinoma the number of monocytes/tumor-associated macrophages (TAM), mature dendritic cells (DC), and Langerhans cells (LHC) was determined using immunohistochemistry. An RNA in situ hybridization technique was used to measure the expression level of GM-CSF, TNF-alpha, IL-12p35, and IL-12p40.

RESULTS

TAM were detected intraepithelial as well as in the stroma of the tumor. LHC were only detected intraepithelial and mature DC only in the tumor stroma. The number of TAM correlated positively with the number of mature DC. The expression levels of GM-CSF and TNF-alpha correlated positively with the number of TAM and DC. TNF-alpha showed a negative correlation with the number of LHC. A significant correlation between the expression of functional IL-12 (IL-12p40) and stromal TAM was found. The expression of GM-CSF, TNF-alpha, and IL-12p40 did not correlate significantly with disease-free survival. However, high IL-12p40 expression was associated with a favorable cumulative overall survival.

CONCLUSIONS

The results suggest that GM-CSF as well as TNF-alpha, produced by cervical carcinoma cells, may play a role in the differentiation of monocytes into mature DC. Furthermore, TNF-alpha may influence the migration of LHC from the tumor.

Tissue homeostasis and cancer

Epithelial cells are known to release an important amount of cytokines capable to modulate immune system functions. On the other hand, immune system cells can release cytokines, which play an important role in the control of the growth of epithelial cells. In this paper, we stand the hypothesis that a mutual (reciprocal) growth regulation exists between epithelial cells and immune system. We propose a model describing plausible cytokine circuits that may regulate (inhibit) both epithelial growth and epithelial inflammation. In addition, we describe how dysfunction of these circuits could lead to tumoral growth, excessive inflammation or both. A failure in the regulation of epithelial growth by the immune system could give rise to a neoplasm, and a failure in the regulation of the immune system by the epithelium could give rise to inflammatory or autoimmune diseases. This model may satisfactorily explain the link between inflammation and cancer.

IL-2 immunotoxin therapy modulates tumor-associated regulatory T cells and leads to lasting immune-mediated rejection of breast cancers in neu-transgenic mice

Studies in cancer patients have suggested that breast tumors recruit regulatory T cells (Tregs) into the tumor microenvironment. The extent to which local Tregs suppress antitumor immunity in breast cancer is unknown. We questioned whether inhibiting systemic Tregs with an IL-2 immunotoxin in a model of neu-mediated breast cancer, the neu-transgenic mouse, could impact disease progression and survival. As in human breast cancer, cancers that develop in these mice attract Tregs into the tumor microenvironment to levels of approximately 10-25% of the total CD4+ T cells. To examine the role of Tregs in blocking immune-mediated rejection of tumor, we depleted CD4+CD25+ T cells with an IL-2 immunotoxin. The treatment depleted Tregs without concomitant lymphopenia and markedly inhibited tumor growth. Depletion of Tregs resulted in a persistent antitumor response that was maintained over a month after the last treatment. The clinical response was immune-mediated because adoptive transfer of Tregs led to a complete abrogation of the therapeutic effects of immunotoxin treatment. Further, Treg down-modulation was accompanied by increased Ag-specific immunity against the neu protein, a self Ag. These results suggest that Tregs play a major role in preventing an effective endogenous immune response against breast cancer and that depletion of Tregs, without any additional immunotherapy, may mediate a significant antitumor response.

HLA-DR+ immature cells exhibit reduced antigen-presenting cell function but respond to CD40 stimulation

Dendritic cells (DC) have been implicated in the defective function of the immune system during cancer progression. We have demonstrated that patients with cancer have fewer myeloid (CD11c+) and plasmacytoid (CD123(hi)) DC and a concurrent accumulation of CD11c(-)CD123- immature cells expressing HLA-DR (DR(+)IC). Notably, DR(+)IC from cancer patients have a reduced capacity to stimulate allogeneic T-cells. DR(+)IC are also present in healthy donors, albeit in smaller numbers. In this study, we assessed whether DR(+)IC could have an impact on the immune response by comparing their function with DC counterparts. For this purpose, DR(+)IC and DC were purified and tested in the presentation of antigens through major histocompatibility complex (MHC) II and MHC-I molecules. DR(+)IC were less efficient than DC at presenting antigens to T-cells. DR(+)IC induced a limited activation of T-cells, eliciting poor T-helper (Th) 1 and preferentially inducing Th2-biased responses. Importantly, despite DR(+)IC's poor responsiveness to inflammatory factors, in samples from healthy volunteers and breast cancer patients, CD40 ligation induced phenotypic maturation and interleukin 12 secretion, in turn generating more efficient T-cell responses. These data underscore the importance of inefficient antigen presentation as a mechanism for tumor evasion and suggest an approach to improve the efficacy of DC-based immunotherapy for cancer.

Water Extract of Cordyceps militaris Enhances Maturation of Murine Bone Marrow-Derived Dendritic Cells in Vitro

Water extract (WE) of Cordyceps militaris has been reported to produce antitumor and immunomodulatory activities in vivo and in vitro. However, the therapeutic mechanism has not been known. In this study, we investigated whether water extract of C. militaris induces the phenotypic and functional maturation of dendritic cells (DC). It profoundly increased CD40, CD54, CD80, CD86, and MHC class II expression in murine bone marrow (BM)-derived myeloid DC. Endocytosis was assessed by the uptake of FITC-dextran and FITC-albumin. The ability of unstimulated DC (UT-DC) to uptake dextran and albumin was higher than that of WE- or LPS-stimulated DC (LPS-DC). Also, UT-DC secreted a low concentration of IL-12, while WE- or LPS-DC secreted higher levels of IL-12 than UT-DC. WE not only formed morphologically mature DC and clusters, but also induced predominantly functional maturation. Moreover, WE is shown to promote the cytotoxicity of specific-cytotoxic T lymphocyte (CTL) induced by DC which were pulsed with P815 tumor-lysate during the stage of antigen presentation. These results suggest that DC maturation by WE can play a critical role in the improvement of the immunoregulatory function in patients with impaired host defense.

Characterization of dendritic cells in differentiated thyroid cancer

In this study, the types and localization pattern of dendritic cells (DCs), the expression of chemokines on carcinoma cells and of the relevant receptors on DCs, and the adhesion molecules expressed on vascular endothelial cells and DCs were examined in thyroid carcinomas. Papillary carcinoma had a higher frequency of CD1a(+) immature DCs than other thyroid tumours. Macrophage inflammatory protein (MIP)-3 alpha was expressed strongly on the majority of papillary carcinoma cells and weakly on a minority of follicular carcinoma cells. DCs positive for chemokine receptor-6 (CCR-6) were densely accumulated in papillary carcinoma. DC-SIGN(+) DCs were accumulated in papillary carcinoma but rarely in follicular carcinoma. A binding assay for DC-SIGN-mediated adhesion of isolated DCs revealed significant inhibition of DC adhesion to papillary carcinoma tissues by neutralizing antibodies against intercellular adhesion molecule-2 or DC-SIGN. These results clearly indicated marked differences between papillary carcinoma and follicular carcinoma in the accumulation of immature DCs, in MIP-3 alpha expression on carcinoma cells, and in the frequency of CCR-6(+) DCs and DC-SIGN(+) DCs.

Effect of water-soluble proteoglycan isolated from Agaricus blazei on the maturation of murine bone marrow-derived dendritic cells

Water-soluble proteoglycan (WSPG) of Agaricus blazei Murill has been known to stimulate the non-specific complements and humoral immune functions to act as polyclonal activators of B cells and to inhibit tumor growth and metastasis. However, little is known about its immunomodulating effects on murine bone marrow (BM)-derived dendritic cells (DC). In the present study, we examined the maturation process of murine BM-DC. BM cells were cultured in the presence of IL-4 and GM-CSF and the generated immature DC were stimulated with WSPG or LPS (WSPG-DC and LPS-DC, respectively) for 24 h. WSPG significantly enhanced the expression of co-stimulatory molecules (CD80 and CD86) and major histocompatibility complex (MHC) II, as did LPS. IL-12p70 production in WSPG-DC was also identical to that in LPS-DC. The antigen-uptake capacity of WSPG-DC was determined by FITC-labeled dextran uptake. WSPG-DC lost dextran uptake capacity comparable to LPS-DC. The antigen-presenting capacity of WSPG-DC as analyzed by allogeneic T cell proliferation was significantly increased in comparison with immature DC, was identical to LPS-DC, and induced higher levels of IL-2 in responding T cells. These results indicate the immunomodulatory properties of WSPG, which might be therapeutically useful in the control of cancers and immunodeficient diseases through the up-regulation of DC maturation.

Workshop on Cancer Biometrics: Identifying Biomarkers and Surrogates of Cancer in Patients

The current excitement about molecular targeted therapies has driven much of the recent dialog in cancer diagnosis and treatment. Particularly in the biologic therapy of cancer, identifiable antigenic T-cell targets restricted by MHC molecules and the related novel stress molecules such as MICA/B and Letal allow a degree of precision previously unknown in cancer therapy. We have previously held workshops on immunologic monitoring and angiogenesis monitoring. This workshop was designed to discuss the state of the art in identification of biomarkers and surrogates of tumor in patients with cancer, with particular emphasis on assays within the blood and tumor. We distinguish this from immunologic monitoring in the sense that it is primarily a measure of the tumor burden as opposed to the immune response to it. Recommendations for intensive investigation and targeted funding to enable such strategies were developed in seven areas: genomic analysis; detection of molecular markers in peripheral blood and lymph node by tumor capture and RT-PCR; serum, plasma, and tumor proteomics; immune polymorphisms; high content screening using flow and imaging cytometry; immunohistochemistry and tissue microarrays; and assessment of immune infiltrate and necrosis in tumors. Concrete recommendations for current application and enabling further development in cancer biometrics are summarized. This will allow a more informed, rapid, and accurate assessment of novel cancer therapies.

Comparative histology of lymph nodes from aged animals and humans with special reference to the proportional areas of the nodal cortex and sinus

Lymph nodes are composed of a lymphocyte-rich area or cortex (subdivided into the superficial and deep cortex and the medullary cord) and another, macrophage-rich area (incorporating the subcapsular and medullary sinuses). We measured the proportional area of the cortex in lymph nodes from aged experimental mammals (rats, guinea pigs, dogs and rabbits) and elderly Japanese humans. The cervical, axillary and inguinal nodes were generally richer in cortex tissue than the pulmonary regional and mesenteric nodes. Histological heterogeneity and medullary sinus dominance were much more evident in the human nodes than in those from animals, except for the guinea pig thoracic node. Human pulmonary regional nodes were characterized by a large medullary sinus; in guinea pigs, these nodes had a similar histology but the T lymphocyte-containing areas were smaller and thinner than in humans. The paraaortic node was well developed in humans and dogs, but not in other animals tested. These species- and region-specific histological differences may influence the evaluation of experimental animal models of lymph node function, such as those recently identified for research into sentinel nodes.

Acidic polysaccharides isolated from Phellinus linteus induce phenotypic and functional maturation of murine dendritic cells

Acidic polysaccharides (PL) isolated from Phellinus linteus are known to stimulate the proliferation of T lymphocytes and humoral immune functions to act as a polyclonal activator of B cells, and to inhibit tumor growth and metastasis. However, little is known about their immunomodulating effects or the effects of its mechanisms on murine bone marrow (BM)-derived dendritic cells (DC). In this study, it profoundly increased CD80, CD86, MHC I, and MHC II expression in murine, GM-CSF and IL-4 stimulated, BM-derived myeloid DC. The ability of unstimulated DC to uptake dextran was higher than that of PL- or LPS-stimulated DC. We analyzed the concentration of IL-12 secreted by DC using flow cytometry and ELISA. Untreated DC secreted a low concentration of IL-12, while PL- or LPS-stimulated DC secreted higher levels of IL-12 than untreated DC. There were no remarkable differences in the concentrations of IL-12 produced by PL- or LPS-stimulated DC. However, polymyxin B (PB; an LPS inhibitor) effectively inhibited the surface molecules and IL-12 production induced by LPS, but had no effect on the PL in DC. PL-treated DC were much more potent antigen-presenting cells in allogeneic immune response than untreated DC. PL treatment not only formed morphologically mature DC but also induced predominant migration to lymphoid tissues. Moreover, the inhibitors of protein tyrosine kinase (PTK) or protein kinase C (PKC) significantly blocked the expression of surface molecules and IL-12 production in PL-stimulated DC. Treatment of DC with PL directly induced PKC activity and phosphorylated PTK. Furthermore, CD11b and/or CD18 partially mediated PL-induced DC maturation.

Tumor antigens and antigen-presenting capacity in breast cancer

AIMS

Cancer cells frequently express antigens capable of being recognized by the host immune system; however, any resultant immune response is often ineffective. This may be related in part to tumor-induced defects in antigen presentation. We screened for dendritic cell infiltration, tumor MHC II expression and associated lymphocytic reaction in the context of three established breast tumor antigens.

METHODS

Forty primary breast tumors were evaluated by immunohistochemical techniques for expression of her2/neu, p53, and MUC1 and MHC class II molecules. Twenty-five samples were further analyzed for p53 mutations by PCR-SSCP analysis and DNA sequencing. The phenotype of tumor-infiltrating inflammatory cells was evaluated using the following markers: CD1a, MHC Class II, CD3, CD45, and CD45RO.

RESULTS

Tumors with p53 mutations and overexpression, but not her2/neu or MUC1 overexpressing tumors, more frequently harbored marked CD1a+ dendritic cell infiltrates. An overall correlation between CD1a+ cell infiltrates and HLA class II expression on tumor cells (p = 0.0008) was also observed and these tumors had greater CD45RO+ lymphocytic infiltrates.

CONCLUSIONS

In breast cancer, p53 mutations may present a more visible signal to the immune system and hence provide a better target for immunotherapy. Infiltrating CD1a positive cells are associated with a more dense tumor lymphocytic infiltrate and tumor cell expression of MHC II molecules.

Gaps and fragmentation of the superficial cortex in the abdominal and pelvic lymph nodes of elderly Japanese

Gaps and fragmentation of the superficial lymph node cortex are considered to provide intranodal shunt flow between the afferent and efferent vessels. Using serial sections of 205 nodes obtained from 27 donated cadavers more than 70 years of age, we examined the histological architecture of the abdominal and pelvic nodes in elderly Japanese. Secondary follicles were rare in the specimens. Cortex gaps were, to a greater or lesser degree, found in all nodes. We classified these nodes into three types according to how often the gap occurred. Type 1 nodes, with a relatively complete shield for the afferent lymph, were most frequently found in gastric nodes, whereas type 3 nodes, with numerous gaps, were often observed in the colic, para-aortic and pelvic nodes. The type 3 nodes showed a specific architecture characterized by a fragmented superficial cortex, three-dimensionally assembled cords and a common sinus between them. Primary follicles were located in the assembled cord structures as well as at the superficial cortex. Irrespective of the type, B and T lymphocyte areas were intermingled in the cortex-like areas. The present results reveal region-specific histological heterogeneity in aged human visceral nodes. Due to increased surface areas, the type 3 architecture seemed to accelerate systemic immunity rather than act as a local barrier in the para-aortic and pelvic nodes, which are located centrally along the lymphatic drainage routes. However, thick trabeculae often seemed to develop in the type 3 sinus to decrease nodal function with aging.

CD1a-positive infiltrating-dendritic cell density and 5-year survival from human breast cancer

Infiltrating CD1a(+) dendritic cells (DCs) have been associated with increased survival in a number of human cancers. This study investigated DC infiltration within breast cancers and the association with survival. Classical established prognostic factors, of tumour size, lymph node status, histological grade, lympho-vascular invasion, the KI-67 (MIB-1) fraction and the Nottingham Prognostic Index (NPI) were also compared. A total of 48 breast cancer patients were followed from the time of surgery and CD1a density analysis for 5 years or until death. Our data set validated previous studies, which show a relationship between survival and the NPI (P<0.001), tumour size (P<0.01) and lymph node status (P<0.05). Although more patients were alive at the 5-year time point in the group with higher CD1a DC density than the lower CD1a DC group, this failed to reach statistical significance at the P=0.05 level. Analysis at 10 years postsurgery is required to investigate the association further.

Dendritic cell and effector cell infiltration in soft tissue sarcomas with reactive lymphoid hyperplasia

The lymph node is the site of antigen presentation, and dendritic cells are sentinels for anti-tumor immunity. However, little is known about the histological features of lymph nodes and dendritic cells in soft tissue sarcomas. The reactive lymph node and infiltration of dendritic cells or effector cells were studied histologically in 10 soft tissue sarcomas with reactive lymphoid hyperplasia. The cases included four malignant fibrous histiocytomas, two malignant peripheral nerve sheath tumors, one synovial sarcoma, one epithelioid sarcoma, one malignant granular cell tumor, and one liposarcoma. The proportions of the T zone, lymphoid follicle, and lymphoid sinus (which was occupied by cells immunopositive for antibodies against CD3, CD20, or CD68) were 33.4% +/- 11.0%, 6.1% +/- 4.9%, and 13.5% +/- 6.5%, respectively. T zone hyperplasia was observed in all cases, and sinus histiocytosis was found in four. The proportion of the T zone in regional lymph nodes of soft tissue sarcoma patients was significantly higher than that in adult autopsy cases without a cancer history. CD8-, TIA-1-, or granzyme B-positive effector cells were found in each sarcoma tissue. Whereas CD1a-positive dendritic cells were not detected, S-100 protein-positive or CD83-positive dendritic cells were observed in five sarcoma tissues. The coefficient correlation between the numbers of effector cells and dendritic cells positive for CD83 or S-100 protein were demonstrated. Although this is a preliminary report, the present study demonstrated that some soft tissue sarcoma patients showed reactive lymphoid hyperplasia. Furthermore, the association between the infiltration of dendritic cells and that of effector cells was observed in patients with soft tissue sarcomas.

Human regional lymph nodes draining cancer exhibit a profound dendritic cell depletion as comparing to those from patients without malignancies

Dendritic cells (DCs) are bone-marrow derived 'professional' antigen presenting cells (APC). They are considered as the most potent APC able to induce primary immune responses. DC efficiently capture and process proteic and non-proteic antigens. They are widely distributed throughout the body and occupy sentinel positions such as epithelia. Establishment of an immune response against cancer may depend of the capacity of DCs to transfer (to capture, to process and to present) tumor antigens into regional lymph nodes where they can induce a specific response leading to tumor rejection. Because host 'professional' DCs are one of the most important elements in the induction of specific anti-tumor responses and lymph nodes are the places where the immune response takes place, we investigated the densities of DCs within regional metastasis-free lymph nodes from 47 patients with different malignant epithelial tumors as comparing with lymph nodes from 11 patients without malignancies using an immunohistochemistry method with anti-S100 protein, CD86 and CD1a antibodies. By means of morphometric analysis, we observed that S100+ and CD1a+ DCs densities in regional lymph nodes from cancer patients were significatively decreased as compared with control lymph nodes (P<0.0001 and 0.003, respectively). S100+ DCs and CD86+ DCs densities in lymph nodes draining cancer were similar. Taken together, these data indicated that lymph nodes draining cancer had significantly less CD1a+ DCs than S100+ and possibly CD86+ DCs. These findings may represent another mechanism by which tumors evade the immune recognition.

Ceramide mediates tumor-induced dendritic cell apoptosis

Induction of apoptosis in dendritic cells (DC) is one of the escape mechanisms of tumor cells from the immune surveillance system. This study aimed to clarify the underlying mechanisms of tumor-induced DC apoptosis. The supernatants (SN) of murine tumor cell lines B16 (melanoma), MCA207, and MCA102 (fibrosarcoma) increased C16 and C24 ceramide as determined by electrospray mass spectrometry and induced apoptosis in bone marrow-derived DC. N-oleoylethanolamine or D-L-threo 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP), which inhibits acid ceramidase or glucosylceramide synthase and then increases endogenous ceramide, enhanced DC apoptosis and ceramide levels in the presence of tumor SN. Pretreatment with L-cycloserine, an inhibitor of de novo ceramide synthesis, or phorbol ester, 12-O-tetradecanoylphorbol-13-acetate reduced endogenous ceramide levels and protected DC from tumor-induced apoptosis. However, other DC survival factors, including LPS and TNF-alpha, failed to do so. The protective activity of 12-O-tetradecanoylphorbol-13-acetate is abrogated by pretreatment with phosphoinositide 3-kinase (PI3K) inhibitor, LY294002. Therefore, down-regulation of PI3K is the major facet of tumor-induced DC apoptosis. Tumor SN, N-oleoylethanolamine, or PDMP suppressed Akt, NF-kappaB, and bcl-x(L) in DC, suggesting that the accumulation of ceramide impedes PI3K-mediated survival signals. Taken together, ceramide mediates tumor-induced DC apoptosis by down-regulation of the PI3K pathway.