Selectins and anti-CD15 (Lewis x/a) antibodies transmit activation signals in Hodgkin's lymphoma-derived cell lines

Lewis x-carrying O-glycans are candidate modulators for conceptus attachment in pigs†

Successful attachment of conceptus to the uterine luminal epithelium (LE) is crucial for establishing a functional placenta in pigs. However, the underlying mechanisms are yet to be elucidated. The uterine LE-conceptus interface is enriched in various glycoconjugates essential to implantation. Using MALDI-MS profiling, we identified for the first time the O-glycan repertoire of pig endometrium during the conceptus attachment stage. The expression pattern of blood group A, O(H), Lewis x, y, a, b (Lex, Ley, Lea, and Leb), the sialylated and sulfated Lex antigens in the uterine LE-conceptus interface was assessed using immunofluorescence assays. Notably, the Lex-carrying O-glycans exhibited a temporal-spatial expression pattern. They were absent in the endometrium on estrous cycle days but strongly and spatially presented in the conceptus and uterine LE to which the conceptus apposes during the early conceptus attachment stage. In addition, Lex-carrying O-glycans were co-localized with secreted phosphoprotein 1 (SPP1), a well-characterized factor that plays a role in promoting conceptus attachment through interacting with integrin αVβ3 and integrin αVβ6. Meanwhile, the immunoprecipitation assays revealed an interaction between the Lex-carrying O-glycans and SPP1, integrin αV, and integrin β6. Furthermore, we provided evidence that the β1,4-galactosyltransferase 1 (B4GALT1) gene is a potential regulator for Lex antigen expression in the uterine LE-conceptus interface during the early conceptus attachment stage. In conclusion, our findings show that Lex-carrying O-glycans, presumably dependent on B4GALT1 gene expression, might modulate conceptus attachment by interacting with the SPP1-integrin receptor complex in pigs.

Prognostic and Therapeutic Role of CD15 and CD15s in Cancer

Simple Summary

CD15 (Lewis X) is a typical myeloid antigen presented in myeloid and monocytic lineages of cells. This molecule interacts with E-, L- and P-selectins, which allows for adhesion with endothelial cells. CD15 is found on various cancer cells, including renal cancer, prostate and bladder cancers, acute leukaemias, hepatocellular carcinoma, breast cancer and melanoma cells. Its high expression can serve as a prognostic marker for patients and is a potentially valuable target for immunotherapy against cancer. Blockage of the antigen’s function results in reduced metastatic potential and it may be an immunotherapeutic target. CD15s is a sialyl derivative of CD15; however, unlike the high expression of CD15, which is a prognostic factor in Hodgkin lymphoma, CD15s relates to poor prognosis for patients. CD15 is considered a marker of cancer stem cells. This review presents a comprehensive description of the prognostic role of CD15 and CD15s and their use in anticancer therapy.

Abstract

CD15 (Lewis X/Lex) is a fucosyl (3-fucosly-N-acetyl-lactosamine) moiety found on membrane proteins of various cancer cells. These cancers include renal cancer, prostate and bladder cancers, acute leukaemias, hepatocellular carcinoma, breast cancer and melanoma. The biological role of CD15 is interaction with E-, L- and P-selectins (adhesion molecules), allowing for adhesion with endothelial cells. In this way, cancer cells start to interact with the endothelia of blood vessels and consequently move out from the blood flow to the surrounding tissues. Blockage of the antigen’s function results in reduced metastatic potential. Moreover, the molecule may be a therapeutic target against cancer in monoclonal antibody-based therapies. CD15 may serve as a prognostic marker for patients and there are high hopes for its use in the immunotherapeutic treatment of tumours. CD15s is a sialyl derivative of CD15 that possesses its own unique characteristics. Its soluble form may act as a competitive inhibitor of the interaction of cancer cells with epithelial cells and thus disallow migration through the vessels. However, the prognostic relevance of CD15 and CD15s expression is very complex. This review presents a comprehensive description of the role of CD15 and CD15s in cancer development and metastasis and overviews its significance for clinical applications.

Papillary Renal Neoplasm With Reverse Polarity: A Clinicopathologic Study of 7 Cases

Papillary renal neoplasm with reverse polarity is a form of recently described tumor. These tumors are defined by GATA3 positivity, negative vimentin staining, and the presence of both papillary structures and a layer of eosinophilic cells with apical nuclei and a granular cytoplasm. In the present report, we review 7 cases of papillary renal neoplasm with reverse polarity that were GATA3+ and vimentin-, consistent with past reports. In all 7 of these cases, we found that these tumors were additionally positive for 34βE12. All 7 of these tumors were categorized as stage pT1. On histological examination, these tumors exhibited branching papillae with apical nuclei. All 7 of these patients were alive on most recent follow-up, with 6 being disease free and one having developed prostate cancer. Together, this overview of 7 additional cases of papillary renal neoplasm with reverse polarity offers further insight into this rare and poorly understood disease.

Loss of CD15 expression in clear cell renal cell carcinoma is correlated with worse prognosis in Chinese patients

Purpose

To explore the role of CD15 expression in the prognosis of clear cell renal cell carcinoma (ccRCC) in Chinese patients.

Methods

The study included 301 patients who had undergone surgery for localized ccRCC. All paraffin-embedded tumor sections were collected to make a set of tissue microarrays. CD15 expression was assessed by immunohistochemistry. The relationship between CD15 expression and survival parameters, clinicopathology features was assessed. Kaplan-Meier and Cox proportional hazards model were utilized to determine the correlation between CD15 expression and overall survival (OS).

Results

The median follow-up time was 54.6 months (range, 3-121 months). The positive rate of CD15 expression was 81.7% (246/301). The cut-off value of CD15 expression was defined as the maximum for Youden index by plotting the receiver operating characteristic curve for survival status. As the threshold was 0.5, all cases were divided into two groups: positive expression group and negative expression group. In correlation analysis, loss of CD15 expression was correlated with female gender, higher Fuhrman nuclear grade, with sarcomatoid differentiation, with necrosis, and with vascular invasion. Kaplan-Meier analysis indicated that the OS time of patients with loss of CD15 expression was shorter than that of patients with positive CD15 expression (P = 0.013).

Conclusion

CD15 is a significant prognostic factor in clear cell renal cell carcinoma.

Synthesis of LewisX-O-Core-1 threonine: A building block for O-linked LewisX glycopeptides

LewisX (LeX) is a branched trisaccharide Galβ1→4(Fucα1→3)GlcNAc that is expressed on many cell surface glycoproteins and plays critical roles in innate and adaptive immune responses. However, efficient synthesis of glycopeptides bearing LeX remains a major limitation for structure-function studies of the LeX determinant. Here we report a total synthesis of a LeX pentasaccharide 1 using a regioselective 1-benzenesulfinyl piperidine/triflic anhydride promoted [3 + 2] glycosylation. The presence of an Fmoc-threonine amino acid facilitates incorporation of the pentasaccharide in solid phase peptide synthesis, providing a route to diverse O-linked LeX glycopeptides. The described approach is broadly applicable to the synthesis of a variety of complex glycopeptides containing O-linked LeX or sialyl LewisX (sLeX).

The p38 pathway, a major pleiotropic cascade that transduces stress and metastatic signals in endothelial cells

By gating the traffic of molecules and cells across the vessel wall, endothelial cells play a central role in regulating cardiovascular functions and systemic homeostasis and in modulating pathophysiological processes such as inflammation and immunity. Accordingly, the loss of endothelial cell integrity is associated with pathological disorders that include atherosclerosis and cancer. The p38 mitogen-activated protein kinase (MAPK) cascades are major signaling pathways that regulate several functions of endothelial cells in response to exogenous and endogenous stimuli including growth factors, stress and cytokines. The p38 MAPK family contains four isoforms p38α, p38β, p38γ and p38δ that are encoded by four different genes. They are all widely expressed although to different levels in almost all human tissues. p38α/MAPK14, that is ubiquitously expressed is the prototype member of the family and is referred here as p38. It regulates the production of inflammatory mediators, and controls cell proliferation, differentiation, migration and survival. Its activation in endothelial cells leads to actin remodeling, angiogenesis, DNA damage response and thereby has major impact on cardiovascular homeostasis, and on cancer progression. In this manuscript, we review the biology of p38 in regulating endothelial functions especially in response to oxidative stress and during the metastatic process.

The Differential Expression of Galectin-1 and Galectin-3 in Normal Lymphoid Tissue and Non-Hodgkin's and Hodgkin's Lymphomas

The WHO classification of lymphomas was established on the basis of clinical, morphological, immunohistochemical and genetic criteria. However, each entity displays its own spectrum of clinical aggressiveness. Treatment success varies widely and is not predictable. Since galectins are involved in oncogenesis and the physiology of immune cells, we investigated whether galectin-1 and galectin-3 immunohistochemical expression could differ in 25 normal lymphoid tissues, 42 non-Hodgkin's and 14 Hodgkin's lymphomas. Immunohistochemical galectin expression was submitted to semi-quantitative and quantitative (computer-assisted microscopy) evaluations. This study is completed by an analysis (by means of quantitative RT-PCR) of galectin-3 mRNA expression in 3 normal lymph nodes, 3 follicular lymphomas (FLs) and 3 diffuse large B-cell lymphomas (DLBCLs). The data show that in normal lymphoid tissue, lymphocytes do not express galectin-1 and rarely express galectin-3. In contrast, galectin-3 was expressed in 8 of the 16 DLBCL cases and in 1 of the 8 FL cases. Furthermore, galectin-3 mRNA was expressed 3-times more in the DLBCLs than in the FLs. While the blood vessel walls of the lymphomas expressed galectin-1, the vessel walls of normal lymphoid tissues did not. This expression of galectin-1 in blood vessel walls was correlated with vascular density. The present study thus shows that DLBCL can be distinguished from normal lymphoid tissue and other lymphomas on the basis of galectin-3 expression.

Glycan modification of antigen alters its intracellular routing in dendritic cells, promoting priming of T cells

Antigen uptake by dendritic cells and intracellular routing of antigens to specific compartments is regulated by C-type lectin receptors that recognize glycan structures. We show that the modification of Ovalbumin (OVA) with the glycan-structure Lewis^X (Le^X) re-directs OVA to the C-type lectin receptor MGL1. Le^X-modification of OVA favored Th1 skewing of CD4⁺ T cells and enhanced cross-priming of CD8⁺ T cells. While cross-presentation of native OVA requires high antigen dose and TLR stimuli, Le^X modification reduces the required amount 100-fold and obviates its dependence on TLR signaling. The OVA-Le^X-induced enhancement of T cell cross-priming is MGL1-dependent as shown by reduced CD8⁺ effector T cell frequencies in MGL1-deficient mice. Moreover, MGL1-mediated cross-presentation of OVA-Le^X neither required TAP-transporters nor Cathepsin-S and was still observed after prolonged intracellular storage of antigen in Rab11⁺LAMP1⁺ compartments. We conclude that controlled neo-glycosylation of antigens can crucially influence intracellular routing of antigens, the nature and strength of immune responses and should be considered for optimizing current vaccination strategies.

DOI:http://dx.doi.org/10.7554/eLife.11765.001

Immune cells called dendritic cells play a crucial role in defending the body against tumor cells and invading viruses. The dendritic cells take up molecules called antigens from these threats and then display them on their surface. This enables the antigens to be identified by other immune cells that are capable of killing the viruses and the tumor cells. The dendritic cells recognize the antigens with the help of receptor proteins called C-type lectin receptors (CLRs). These receptors can bind to sugar molecules that are naturally found on many antigens. For example, a C-type lectin receptor called MGL1 can bind to sugars known as Lewis^X and Lewis^a on tumor and virus proteins. However, it is not clear how important these receptors are in triggering immune responses.

An antigen called Ovalbumin – which is found in chicken egg white – can trigger immune responses in mammals and so researchers often use it to study the immune system. Although this antigen has several sugar molecules attached to it, quite a large amount of Ovalbumin is needed to trigger strong immune responses. Now, Streng-Ouwehand et al. examine whether attaching Lewis^X to Ovalbumin can results in stronger immune responses in mice.

The experiments show that injecting mice with Ovalbumin-Lewis^X triggers a much stronger immune response than normal Ovalbumin does. This enhanced response was not observed in mice that lacked the MGL1 receptor, which suggests that this receptor is involved in detecting Ovalbumin-Lewis^X. Furthermore, the dendritic cells store the altered Ovalbumin for longer than they store normal Ovalbumin, which gives the cells more time to present the altered Ovalbumin to other immune cells.

Vaccines and some other therapies help to boost immune responses to viruses and tumors by exposing the body to antigens. However, these therapies often use antigens that don’t have sugar molecules attached to them, or are missing the sugar molecules they would normally have. Streng-Ouwehand et al.’s findings suggest that adding specific sugars to antigens in immune therapies might help to make these therapies more effective.

DOI:http://dx.doi.org/10.7554/eLife.11765.002

Hodgkin lymphoma cell lines bind to platelets. Incubation with platelets induces CD15 and P-selectin dependent adhesion of the cell lines to Human Umbilical Vein Endothelial cells (HUVEC)

Hodgkin's lymphoma is believed to spread in an orderly fashion within the lymphatic compartment. In a minority of cases, after reaching the spleen, the neoplasm disseminates, reminiscent of metastasis. In the spleen, the Hodgkin-Reed-Sternberg tumor cells come across platelets in the blood vessels and mainly in the splenic red pulp. Based on this knowledge, we investigated the possibility of platelets inducing cell adhesion in Hodgkin's lymphoma cell lines. We showed that L428 and KMH-2 cells strongly adhere to thrombin-activated platelets. Cell adhesion to platelets is partially dependent on CD15 antigens (Lewis(X)), mainly sialyl-CD15, and P-selectin. KMH-2, as compared to L428 cells, showed increased binding due to its differential high expression of the sialyl-CD15. As a consequence of incubation with platelets, KMH-2 cells also produced increased amounts of tumor necrosis factors α (TNFα) followed by enhanced binding to human vascular endothelial cells (HUVEC). Incubation of both cell lines with activated platelets also induced activation of AP-1 transcription complex. Our findings are consistent with the concept that platelets play a critical role in the dissemination of HRS cells in HL, predominantly in the spleen, by increasing cell adhesion and thus promoting their proliferative and migratory properties beyond the lymphatic system.

Cancer vaccines and carbohydrate epitopes

Tumor-associated carbohydrate antigens (TACA) result from the aberrant glycosylation that is seen with transformation to a tumor cell. The carbohydrate antigens that have been found to be tumor-associated include the mucin related Tn, Sialyl Tn, and Thomsen-Friedenreich antigens, the blood group Lewis related Lewis(Y), Sialyl Lewis(X) and Sialyl Lewis(A), and Lewis(X) (also known as stage-specific embryonic antigen-1, SSEA-1), the glycosphingolipids Globo H and stage-specific embryonic antigen-3 (SSEA-3), the sialic acid containing glycosphingolipids, the gangliosides GD2, GD3, GM2, fucosyl GM1, and Neu5GcGM3, and polysialic acid. Recent developments have furthered our understanding of the T-independent type II response that is seen in response to carbohydrate antigens. The selection of a vaccine target antigen is based on not only the presence of the antigen in a variety of tumor tissues but also on the role this antigen plays in tumor growth and metastasis. These roles for TACAs are being elucidated. Newly acquired knowledge in understanding the T-independent immune response and in understanding the key roles that carbohydrates play in metastasis are being applied in attempts to develop an effective vaccine response to TACAs. The role of each of the above mentioned carbohydrate antigens in cancer growth and metastasis and vaccine attempts using these antigens will be described.

Glycoproteomic characterization of carriers of the CD15/Lewisx epitope on Hodgkin's Reed-Sternberg cells

Background

The Lewis^x trisaccharide, also referred to as the CD15 antigen, is a diagnostic marker used to distinguish Hodgkin's lymphoma from other lymphocytic cancers. However, the role of such fucosylated structures remains poorly understood, in part because carriers of Lewis^x structures on Hodgkin's Reed-Sternberg cells have not been identified.

Methods

GalMBP, an engineered carbohydrate-recognition protein that binds selectively to oligosaccharides with paired terminal galactose and fucose residues, has been used in conjunction with proteomic and glycomic analysis to identify glycoprotein carriers of Lewis^x and related glycan structures in multiple Hodgkin's Reed-Sternberg cell lines.

Results

Multiple glycoproteins that bind to GalMBP and carry CD15/Lewis^x have been identified in a panel of six Reed-Sternberg cell lines. The most commonly identified Lewis^x-bearing glycoproteins are CD98hc, which was found in all six cell lines tested, and intercellular adhesion molecule-1 and DEC-205, which were detected in five and four of the lines, respectively. Thus, several of the most prominent cell adhesion molecules on the lymphomas carry this characteristic glycan epitope. In addition, the Hodgkin's Reed-Sternberg cell lines can be grouped into subsets based on the presence or absence of less common Lewis^x-bearing glycoproteins.

Conclusions

CD98 and intercellular adhesion molecule-1 are major carriers of CD15/Lewis^x on Reed-Sternberg cells. Binding of DC-SIGN and other glycan-specific receptors to the Lewis^x epitopes on CD98 and intercellular adhesion molecule-1 may facilitate interaction of the lymphoma cells with lymphocytes and myeloid cells in lymph nodes.

Selectins and selectin ligands in extravasation of cancer cells and organ selectivity of metastasis

Metastatic spreading is a dreadful complication of neoplastic diseases that is responsible for most deaths due to cancer. It consists in the formation of secondary neoplasms from cancer cells that have detached from the primary site. The formation of these secondary sites is not random and several clinical observations indicate that the metastatic colonization exhibits organ selectivity. This organ tropism relies mostly on the complementary adhesive interactions between the cancer cells and their microenvironment. In particular, several lines of evidence suggest that the organ selectivity of colon cancer cells for the liver involves the binding of the circulating cancer cells to endothelial E-selectin. The aim of this review is to make an integrative up-date of the mechanisms that govern the organ selectivity of the metastatic process focusing more especially on the role of selectins and selectin ligands.

Lewis x antigen mediates adhesion of human breast carcinoma cells to activated endothelium. Possible involvement of the endothelial scavenger receptor C-type lectin

Lewis x (Le(x), CD15), also known as SSEA-1 (stage specific embryonic antigen-1), is a trisaccharide with the structure Galbeta(1-4)Fucalpha(1-3)GlcNAc, which is expressed on glycoconjugates in human polymorphonuclear granulocytes and various tumors such as colon and breast carcinoma. We have investigated the role of Le(x) in the adhesion of MCF-7 human breast cancer cells and PMN to human umbilical endothelial cells (HUVEC) and the effects of two different anti-Le(x) mAbs (FC-2.15 and MCS-1) on this adhesion. We also analyzed the cytolysis of Le(x+)-cells induced by anti-Le(x) mAbs and complement when cells were adhered to the endothelium, and the effect of these antibodies on HUVEC. The results indicate that MCF-7 cells can bind to HUVEC, and that MCS-1 but not FC-2.15 mAb inhibit this interaction. Both mAbs can efficiently lyse MCF-7 cells bound to HUVEC in the presence of complement without damaging endothelial cells. We also found a Le(x)-dependent PMN interaction with HUVEC. Although both anti-Le(x) mAbs lysed PMN in suspension and adhered to HUVEC, PMN aggregation was only induced by mAb FC-2.15. Blotting studies revealed that the endothelial scavenger receptor C-type lectin (SRCL), which binds Le(x)-trisaccharide, interacts with specific glycoproteins of M (r ) approximately 28 kD and 10 kD from MCF-7 cells. The interaction between Le(x+)-cancer cells and vascular endothelium is a potential target for cancer treatment.

CD34+-derived CD11c+++ BDCA-1++ CD123++ DC: expansion of a phenotypically undescribed myeloid DC1 population for use in adoptive immunotherapy

BACKGROUND

DC are commonly defined as HLA-DR+/Lin- cells that can be CD11c+ + + CD123+/ -, termed DC1/myeloid DC that induce a Th1 response, or CD11c- CD123+ + +, termed DC2/lymphoid DC that induce a Th2 response. However, significant heterogeneity within DC preparations is apparent and supports the existence of several distinct DC subpopulations. This study aimed to expand and characterize CD34+ DC for use in immunotherapy.

METHODS

CD34+ cells were seeded at 1 x 10(5)/mL and expanded for 14 days in RPMI + 10% autologous plasma supplemented with GM-CSF, IL-4, Flt-3L and SCF. Maturation was induced with TNF-alpha and PGE2 for 2 days. DC were analyzed morphologically, phenotypically with a panel of MAb to lineage and DC markers, and functionally in MLR, T-cell assays and T-cell cytokine secretion by ELISA.

RESULTS

Significant cellular expansion was observed: 60+/-5 x 10(6) DC from 1 x 10(6) CD34+ cells (n=28). Phenotypically DC were characterized as HLA-DR+ +, CD11c+ + +, CD80+ +, CD83+, CD86+ +, CD123+ +, CD15+ +, CD33+ +, BDCA-1+ +, CD4+ and Lin-. DC displayed potent allostimulatory capacity and efficient presentation of KLH and tetanus toxin. DC-primed T cells secreted IFN-gamma (Th1); however, no detectable IL-4 (Th2) was noted.

DISCUSSION

We present features of CD34+ DC that have not been previously described. The CD34+ DC generated represent a population of myeloid DC functioning as DC1 but phenotypically expressing markers characteristic of both DC1 and DC2. This novel DC population is capable of inducing naive T-cell responses and can be expanded to clinically useful numbers. CD34+-derived DC represent attractive candidates for use in adoptive T-cell immunotherapy.

Adherence of Hodgkin's disease-derived cell lines to the various lymph node compartments

This adherence study was performed to clarify the trafficking of Hodgkin-Reed-Sternberg (HRS) cells in Hodgkin's disease (HD) and thus try to unravel the peculiar pathways of dissemination in the early stages of this malignant neoplasm. Using non-neoplastic human necropsy or biopsy lymph node as well as tonsillar tissue sections, we have studied the adherence of the KMH-2 and L-428 HD-derived cell lines and have compared it to that of peripheral blood lymphocytes (PBLs). In necropsy lymph nodes, cell lines predominantly adhered to sinuses and paracortex, whilst adhered PBLs were distributed more widely. In biopsy lymph nodes, adhesion to high endothelial venules (HEVs) was rarely observed, whilst cell lines were found to adhere to sinuses. Inhibition by EDTA pretreatment affected adherence to HEVs as well as to sinuses and paracortex to a similar degree. Our findings point to the possible importance of the lymph node sinuses and paracortex in relation to homing of the HRS cells and their dissemination during the early stages of HD. The results suggest a significant primary role of the extracellular matrix of the paracortex and sinuses in the homing of HRS cells, with the HEVs of only secondary importance.