Induction of peripheral lymph node addressin in human gastric mucosa infected by Helicobacter pylori

Developing Method for Minor Acidic O-Glycan Analysis in Mucin and Cancer Cell Samples

Minor acidic glycans, such as sulfated and phosphorylated glycans, constitute only a small fraction of biological glycome, making their analysis a considerable challenge. In this study, we developed a technique to analyze minor acidic O-glycans in biological samples. First, efficient reaction conditions for the release of O-glycans from the proteins were determined. Next, a high-throughput method was established for the recovery of minor acidic glycans using NH2 spin columns. The performance of the established method was evaluated using mucin samples, and sulfated O-glycans were successfully detected in bovine submaxillary gland mucin and porcine stomach mucin. We also analyzed the minor acidic O-glycans in cultured cancer cells. In addition to trifucosylated sulfated O-glycans and disulfated O-glycans, sulfated O-glycans with KDN were detected in LS174T cells. The relative amount of sulfated glycans in LS174T cells was almost 10-fold higher than that in the other cells. Moreover, a large polylactosamine-type sulfated O-glycan with a molecular weight >3500 was detected in MKN45 cells. Interestingly, phosphorylated ribose, possibly bound to serine/threonine, was observed in all the cells used in this study. Thus, our established analytical method allows for the analysis of minor acidic O-glycans that cannot be detected using existing glycomics methods.

Chronic inflammation in benign prostatic hyperplasia: Pathophysiology and treatment options

Benign prostatic hyperplasia, a prevalent condition in aging men, is characterized by the proliferation of prostatic epithelial and stromal cells, which leads to bladder outlet obstruction and the exacerbation of lower urinary tract symptoms. There is increasing evidence that chronic prostatic inflammation contributes to the pathogenesis and progression of benign prostatic hyperplasia. This review explores the complex relationship between chronic inflammation and benign prostatic hyperplasia, focusing on the underlying mechanisms, clinical implications, and current therapeutic approaches. The pathophysiology of benign prostatic hyperplasia is multifaceted, involving factors such as hormonal changes, hypoxia, urine reflux into prostatic ducts and stroma, autoimmune responses, and infection-induced inflammation. Inflammatory cytokines, particularly interleukin-17 and interleukin-8, may play key roles in tissue remodeling and smooth muscle contraction within the prostate, thereby influencing benign prostatic hyperplasia progression. Current therapies for benign prostatic hyperplasia include α1-blockers, phosphodiesterase 5 inhibitors, 5α-reductase inhibitors, and plant-based treatments (e.g., pollen extract). These therapies aim to alleviate symptoms by reducing prostatic inflammation, improving blood flow, and inhibiting hormonal pathways involved in prostatic enlargement. However, patients with chronic prostatic inflammation often experience more severe lower urinary tract symptoms and may be resistant to conventional treatments. This resistance has prompted the exploration of alternative therapies targeting inflammation. Chronic prostatic inflammation plays a central role in the pathogenesis and severity of benign prostatic hyperplasia. An understanding of its mechanisms will enable the development of more effective treatments to improve the quality of life among patients with benign prostatic hyperplasia.

High endothelial venules in intracranial germinomas: Implications for lymphocytes infiltration

PURPOSE

Reactive lymphocytes are substantial components of germinoma, which are believed to be related to the favorable prognosis of this intracranial tumor and better response to immunotherapy. However, the mechanisms managing the recruitment of lymphocytes are poorly understood. High endothelial venules (HEVs) are specialized blood vessels that play key roles in lymphocyte trafficking in Lymph nodes. These vessels are associated with lymphocyte infiltration in chronic inflammatory diseases and various malignant tumors, but their distribution and implications in germinoma are unknown. This study aimed to investigate the distribution and implications of HEVs in intracranial germinomas.

METHODS

We investigated the presence and distribution of HEVs in 42 germinomas by immunohistochemical staining of peripheral node addressin (PNAd) and transmission electron microscopic examination. The correlation of the densities of HEVs with the extent of T and B lymphocyte infiltration and several clinicopathological characteristics were also analyzed to determine whether HEVs are responsible for lymphocyte recruitment and their roles in anti-tumor immunity in germinoma.

RESULTS

PNAd-positive HEVs were detected in 31% (13/42) of germinomas, and their presence correlated with abundant infiltrating CD3+ T cells, CD20 + B cells and CD8+ cytotoxic T lymphocytes (p = 0.0410, 0.0023, and 0.0061, respectively). Higher HEVs density was also correlated with several clinicopathological parameters, which are recognized indicators for favorable prognosis in germinomas, including typical tumor location (p = 0.0093), lower tumor cell content (p = 0.0428), and younger age at diagnosis (p = 0.0121). Furthermore, bioinformatics analysis showed HEVs-associated genes mainly enriched in immune-related Gene Ontology terms, including innate immune response, inflammatory response, and B cell receptor signaling pathway. The xCell analysis revealed that germinomas with higher HEVs enrichment scores had increased levels of the immune score, microenvironment score, dendritic cells, CD8+ central memory T-cells, CD4+ memory T-cells, and B-cells.

CONCLUSIONS

Our findings indicate that HEVs could contribute to lymphocyte recruitment in germinomas, thus may serve as a predictor of favorable prognosis and better response to immunotherapy in this intracranial tumor.

The Percentage of PNAd-Expressing Vessels is Correlated with Disease Severity in Eosinophilic Chronic Rhinosinusitis

BACKGROUND

Eosinophilic chronic rhinosinusitis (ECRS) is a chronic inflammatory condition of the paranasal sinuses characterized by intractable nasal polyps with prominent eosinophil infiltration. These eosinophils are presumably recruited from peripheral blood via vessels expressing peripheral lymph node addressin (PNAd), a set of glycoproteins decorated with 6-sulfo sialyl Lewis x (sLe^x) glycans that serve as L-selectin ligands. Based on the severity classification algorithm proposed by the Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis (JESREC) study group, ECRS is divided into mild, moderate and severe groups; however, as yet there are few reports comparing the clinicopathological differences among these groups.

OBJECTIVE

Our goal was to elucidate clinicopathological differences among the three different severities of ECRS with special reference to eosinophils and PNAd-expressing vessels.

METHODS

We performed quantitative immunohistochemical analysis of PNAd-expressing vessels using surgical specimens of nasal polyps from patients exhibiting varying severity of ECRS (n = 35) and from individuals with non-ECRS (n = 10). To this end, we immunostained tissue sections with anti-PNAd and anti-CD34 monoclonal antibodies, and then determined the number of vessels immunolabeled with each antibody.

RESULTS

The number of eosinophils infiltrating nasal polyps was correlated with ECRS severity. We also found that the PNAd + /CD34 + vessel ratio, namely, the percentage of PNAd-expressing vessels among all vessels, was positively correlated not only with ECRS severity but also with the number of eosinophils infiltrating nasal polyps formed in ECRS.

CONCLUSION

These results strongly suggest that PNAd-expressing vessels play at least a partial role in eosinophil recruitment to nasal polyps and consequent severity of ECRS.

High endothelial venules as potential gateways for therapeutics

High endothelial venules (HEVs) are specialized blood vessels that support the migration of lymphocytes from the bloodstream into lymph nodes (LNs). They are also formed ectopically in mammalian organs affected by chronic inflammation and cancer. The recent arrival of immunotherapy at the forefront of many cancer treatment regimens could boost a crucial role for HEVs as gateways for the treatment of cancer. In this review, we describe the microanatomical and biochemical characteristics of HEVs, mechanisms of formation of newly made HEVs, immunotherapies potentially dependent on HEV-mediated T cell homing to tumors, and finally, how HEV-targeted therapies might be used as a complementary approach to potentially shape the therapeutic landscape for the treatment of cancer and immune-mediated diseases.

Sulfated Glycans Recognized by S1 Monoclonal Antibody can Serve as a Diagnostic Marker for Malignant Pleural Mesothelioma

PURPOSE

Malignant pleural mesothelioma (MPM) is a malignant neoplasm of the pleura caused by asbestos exposure. For diagnosis of MPM, immunohistochemistry using multiple markers is recommended to rule out differential diagnoses, such as pulmonary adenocarcinoma. However, the specificity of currently used markers is not fully satisfactory. We previously developed a monoclonal antibody named S1, which recognizes 6-sulfo sialyl Lewis x, an L-selectin ligand expressed on high endothelial venules. During the screening process, we discovered that this antibody stained normal pleural mesothelium. This finding prompted us to hypothesize that the epitope recognized by S1 might serve as a new diagnostic marker for MPM.

METHODS

To test this hypothesis, we immunostained human MPM (n = 22) and lung adenocarcinoma (n = 25) tissues using S1 antibody.

RESULTS

77.3% of MPM were S1 positive, and if limited to epithelioid type, the positivity rate was 100%, while that of lung adenocarcinoma was only 36.0%. Statistical analysis revealed a significant difference in the S1 positivity rate between each disease. Furthermore, immunohistochemistry using a series of anti-carbohydrate antibodies combined with glycosidase digestion revealed the structure of sulfated glycans expressed in MPM to be 6-sulfo sialyl N-acetyllactosamine attached to core 2-branched O-glycans.

CONCLUSION

We propose that the S1 glycoepitope could serve as a new diagnostic marker for MPM.

Vascular E-selectin Expression Detected in Formalin-fixed, Paraffin-embedded Sections With an E-selectin Monoclonal Antibody Correlates With Ulcerative Colitis Activity

It is widely accepted that E-selectin, an inducible endothelial cell adhesion molecule, plays a critical role in the initial step of neutrophil recruitment to sites of acute inflammation. However, immunohistological analysis of E-selectin has been hampered by lack of E-selectin-specific monoclonal antibodies that can stain formalin-fixed, paraffin-embedded (FFPE) tissue sections. Here, we employed E-selectin•IgM (a soluble form of E-selectin) as immunogen, and then, after negative selection with L-selectin•IgM and P-selectin•IgM and screening of FFPE sections of both COS-1 cells overexpressing E-selectin and acute appendicitis tissues, we successfully generated an E-selectin-specific monoclonal antibody capable of staining FFPE tissue sections. We used this antibody, designated U12-12, to perform quantitative immunohistological analysis of 390 colonic mucosal biopsy specimens representing ulcerative colitis. We found that the higher the histological disease activity, the greater the number of vessels expressing E-selectin, an observation consistent with previous analyses of frozen tissue sections. Furthermore, in active ulcerative colitis, E-selectin-expressing vessels contained neutrophils attached to endothelial cells, presumably in the process of extravasation, which eventually could cause epithelial damage. These results overall indicate that U12-12 is effective for E-selectin immunohistochemistry in archived FFPE samples representing various human diseases.

The Role of L-Selectin in HIV Infection

HIV envelope glycoprotein is the most heavily glycosylated viral protein complex identified with over 20 glycans on its surface. This glycan canopy is thought to primarily shield the virus from host immune recognition as glycans are poor immunogens in general, however rare HIV neutralizing antibodies nevertheless potently recognize the glycan epitopes. While CD4 and chemokine receptors have been known as viral entry receptor and coreceptor, for many years the role of viral glycans in HIV entry was controversial. Recently, we showed that HIV envelope glycan binds to L-selectin in solution and on CD4 T lymphocytes. The viral glycan and L-selectin interaction functions to facilitate the viral adhesion and entry. Upon entry, infected CD4 T lymphocytes are stimulated to progressively shed L-selectin and suppressing this lectin receptor shedding greatly reduced HIV viral release and caused aggregation of diminutive virus-like particles within experimental infections and from infected primary T lymphocytes derived from both viremic and aviremic individuals. As shedding of L-selectin is mediated by ADAM metalloproteinases downstream of host-cell stimulation, these findings showed a novel mechanism for HIV viral release and offer a potential new class of anti-HIV compounds.

The Conspicuousness of High Endothelial Venules in Angioimmunoblastic T-cell Lymphoma Is Due to Increased Cross-sectional Area, Not Increased Distribution Density

Angioimmunoblastic T-cell lymphoma (AITL) is a T-cell lymphoma of follicular helper T-cell origin. Histologically, neoplastic T-cells proliferate to form clusters adjacent to or between arborizing high endothelial venules (HEVs). HEVs in normal lymph nodes express sulfated glycans called peripheral lymph node addressin (PNAd); however, it remains unclear whether PNAd is also expressed on HEVs in AITL. Furthermore, although it is widely accepted that HEVs are conspicuous in AITL due to their proliferation, quantitative histological support for this concept is lacking. To investigate these issues, we employed monoclonal antibodies recognizing PNAd, namely, MECA-79, HECA-452, and 297-11A, and performed quantitative immunohistochemical analysis of HEVs in 36 AITL-affected and 67 normal lymph nodes. Staining with all three antibodies confirmed that AITL HEVs express PNAd. Moreover, AITL HEVs were bound calcium-dependently by L-selectin-IgM fusion proteins, indicating that they function in the recruitment of L-selectin-expressing lymphocytes. Unexpectedly, HEV distribution density was not increased but rather decreased in AITL compared with normal lymph nodes, but HEV cross-sectional area in AITL was significantly greater than that seen in normal lymph nodes. Overall, these results indicate that the prominence of AITL HEVs is likely due to increased cross-sectional area rather than increased distribution density.

High endothelial venules (HEVs) in immunity, inflammation and cancer

High endothelial venules (HEVs) are specialized blood vessels mediating lymphocyte trafficking to lymph nodes (LNs) and other secondary lymphoid organs. By supporting high levels of lymphocyte extravasation from the blood, HEVs play an essential role in lymphocyte recirculation and immune surveillance for foreign invaders (bacterial and viral infections) and alterations in the body’s own cells (neoantigens in cancer). The HEV network expands during inflammation in immune-stimulated LNs and is profoundly remodeled in metastatic and tumor-draining LNs. HEV-like blood vessels expressing high levels of the HEV-specific sulfated MECA-79 antigens are induced in non-lymphoid tissues at sites of chronic inflammation in many human inflammatory and allergic diseases, including rheumatoid arthritis, Crohn’s disease, allergic rhinitis and asthma. Such vessels are believed to contribute to the amplification and maintenance of chronic inflammation. MECA-79⁺ tumor-associated HEVs (TA-HEVs) are frequently found in human tumors in CD3⁺ T cell-rich areas or CD20⁺ B-cell rich tertiary lymphoid structures (TLSs). TA-HEVs have been proposed to play important roles in lymphocyte entry into tumors, a process essential for successful antitumor immunity and lymphocyte-mediated cancer immunotherapy with immune checkpoint inhibitors, vaccines or adoptive T cell therapy. In this review, we highlight the phenotype and function of HEVs in homeostatic, inflamed and tumor-draining lymph nodes, and those of HEV-like blood vessels in chronic inflammatory diseases. Furthermore, we discuss the role and regulation of TA-HEVs in human cancer and mouse tumor models.

Expression of functional E-selectin ligands on the plasma membrane of carcinoma cells correlates with poor prognosis in clear cell renal cell carcinoma

OBJECTIVES

Given the relatively high frequency of metastatic recurrence of clear cell renal cell carcinoma (ccRCC), reliable prognostic markers of ccRCC, particularly those associated with metastasis, are needed. Here, in search of those factors, we assessed the contribution of sialyl Lewis x (sLe^x) and sialyl Lewis a (sLe^a), as well as functional E-selectin ligand carbohydrates expressed on carcinoma cells, to metastasis and consequent poor prognosis in ccRCC.

MATERIALS AND METHODS

Patients who underwent surgical resection (curative nephrectomy) for RCC, and whose post-operative pathological diagnosis was ccRCC (n = 117) were enrolled in this study. Expression of sLe^x/sLe^a carbohydrate antigens in ccRCC was evaluated by immunohistochemistry with an anti-sLe^x/sLe^a monoclonal antibody HECA-452. To evaluate membrane expression of sLe^x/sLe^a carbohydrate antigens quantitatively, we employed a histological scoring system used to evaluate membrane expression of human epidermal growth factor receptor 2 (HER2) in breast cancer. We also conducted an E-selectin•IgM chimera in situ binding assay to assess expression of functional E-selectin ligand carbohydrates in ccRCC. We then carried out statistical analysis to determine whether membrane expression of HECA-452-reactive sLe^x/sLe^a glycans as well as of E-selectin•IgM-binding functional E-selectin ligand carbohydrates correlates with progression-free, overall, or cancer-specific survival.

RESULTS

Based on HECA-452 immunochemistry, 106 of 117 ccRCC specimens expressed detectable levels of sLe^x/sLe^a glycans, primarily on the plasma membrane, and of those, 31 that showed robust membrane expression were judged as HECA-452-positive. Membrane expression of HECA-452-positive sLe^x/sLe^a glycans correlated with shortened progression-free and overall survival. Moreover, in in situ analysis, these HECA-452-positive ccRCC tissues were decorated with E-selectin•IgM chimeric proteins, calcium-dependently. Comparable analysis in normal kidney showed both HECA-452 positivity and chimera binding almost exclusively in epithelial cells that constitute proximal tubules. Membrane expression of functional E-selectin ligand carbohydrates, as detected by the E-selectin•IgM chimera, correlated more significantly with poor prognosis of patients, namely, shortened progression-free, overall and cancer-specific survival, than did HECA-452 positivity.

CONCLUSIONS

Expression of E-selectin•IgM-binding functional E-selectin ligand carbohydrates can serve as a reliable and potentially superior prognostic biomarker of patients with ccRCC.

High endothelial venules (HEVs) in human melanoma lesions: Major gateways for tumor-infiltrating lymphocytes

The presence of tumor-infiltrating lymphocytes (TILs) is a strong prognostic parameter for local dissemination and overall survival in melanoma. Lymphocyte migration from blood into peripheral tissues is mainly regulated by vascular endothelium. However, the blood vessels and mechanisms governing the recruitment of TILs in melanoma tumors remain poorly understood. Here, we show that high endothelial venules (HEVs), specialized blood vessels for lymphocyte extravasation into lymphoid tissues, are frequently found in melanoma tumors and are associated with high levels of lymphocyte infiltration. The analysis of 225 primary melanomas revealed that lymphocytes specifically infiltrated HEV-rich areas of melanoma tumors and that the density of MECA-79+ HEVs was variable among patients and strongly correlated with CD3+, CD8+ and CD20+ TIL densities. Inflammatory (CCL5, CXCL9, CXCL10 and CXCL11) and lymphoid (CCL21, CCL19 and CXCL13) chemokines as well as TH1 and naïve T-cell genes were overexpressed in melanoma samples with high densities of tumor HEVs. Mature dendritic cells (mDCs) were frequently found around tumor HEVs and densities of HEVs and DC-LAMP+ mDCs within tumor stroma were strongly correlated. DCs which maintain HEVs in lymph nodes, may thus also contribute to the regulation of HEVs in melanomas. Finally, we found significantly higher densities of tumor HEVs in melanomas with tumor regression, low Clark level of invasion and thin Breslow thickness (all p < 0.001). The strong association between tumor HEVs, TILs, mDCs and clinical parameters of melanoma, supports a critical role for HEVs in limiting malignant melanoma development through both naïve and effector T-lymphocyte recruitment and activation.

Induction of High Endothelial Venule-like Vessels in Oral and Cutaneous Lichen Planus: A Comparative Study

Lichen planus (LP) is a chronic inflammatory mucocutaneous disease involving the oral mucosa and skin. Both oral LP (OLP) and cutaneous LP (CLP) are histopathologically characterized by dense subepithelial lymphocyte infiltrates; however, the mechanisms underlying lymphocyte recruitment to sites of LP lesions are not fully understood. Here, we assessed the induction of peripheral lymph node addressin (PNAd)-expressing high endothelial venule (HEV)-like vessels in 19 OLP and 17 CLP cases. To do so, we performed immunohistochemical staining for PNAd and CD34, followed by quantitative analysis. We also conducted triple immunohistochemistry for PNAd and either CD3 and CD20 or CD4 and CD8 to identify the lymphocyte subset preferentially recruited via HEV-like vessels. PNAd-expressing HEV-like vessels were induced in and around lymphocyte aggregates in all cases of OLP and in 10 of 17 CLP cases, and these vessels were more frequently observed in OLP relative to CLP. Although the number of T-cells attached per HEV-like vessel exceeded the number of B-cells in both OLP and CLP, the number of CD4⁺ T-cells attached was greater than the number of CD8⁺ T-cells only in OLP. These findings combined suggest that PNAd-expressing HEV-like vessels play a more important role in the pathogenesis of OLP compared with CLP.

Preferential expression of sialyl 6'-sulfo N-acetyllactosamine-capped O-glycans on high endothelial venules in human peripheral lymph nodes

Lymphocyte "homing", the physiologic trafficking of lymphocytes from the circulation to secondary lymphoid organs, is regulated by sequential adhesive interactions between lymphocytes and endothelial cells that constitute high endothelial venules (HEVs). Initial lymphocyte "rolling" is mediated by relatively weak, transient adhesive interactions between L-selectin expressed on lymphocytes and sulfated mucin-type O-glycans expressed on HEVs. Keratan sulfate galactose (Gal)-6-O-sulfotransferase (KSGal6ST) catalyzes 6-O-sulfation of Gal in keratan sulfate glycosaminoglycan chains but also transfers sulfate to Gal in much shorter glycan chains, such as sialylated N-acetyllactosamine (LacNAc)-capped O-glycans. In mice, KSGal6ST is reportedly expressed in HEVs and functions in synthesizing 6-sulfo Gal-containing O-glycans on HEVs. However, in humans, the presence of 6-sulfo Gal-containing O-glycans on HEVs is not reported. Employing the newly developed monoclonal antibody 297-11A, which recognizes non-sialylated terminal 6'-sulfo LacNAc, we demonstrate that sialyl 6'-sulfo (and/or 6,6'-disulfo) LacNAc-capped O-glycans are preferentially displayed on HEVs in human peripheral lymph nodes (PLNs) and to a lesser extent in mesenteric LNs (MLNs) but not in Peyer's patches (PPs). We also found that the scaffold protein mucosal addressin cell adhesion molecule 1 (MAdCAM-1), which is expressed on HEVs in PPs and MLNs but not PLNs, was modified by 297-11A-positive sulfated glycans less efficiently than was CD34. Moreover, 297-11A-positive sulfated glycans were also displayed on HEV-like vessels induced in tumor-infiltrating lymphocyte (TIL) aggregates formed in various cancers. These findings collectively indicate that 297-11A-positive sulfated glycans potentially play a role in physiologic lymphocyte homing as well as in lymphocyte recruitment under pathologic conditions.

Analysis of A4gnt Knockout Mice Reveals an Essential Role for Gastric Sulfomucins in Preventing Gastritis Cystica Profunda

Gastric adenocarcinoma cells secrete sulfomucins, but their role in gastric tumorigenesis remains unclear. To address that question, we generated A4gnt/Chst4 double-knockout (DKO) mice by crossing A4gnt knockout (KO) mice, which spontaneously develop gastric adenocarcinoma, with Chst4 KO mice, which are deficient in the sulfotransferase GlcNAc6ST-2. A4gnt/Chst4 DKO mice lack gastric sulfomucins but developed gastric adenocarcinoma. Unexpectedly, severe gastric erosion occurred in A4gnt/Chst4 DKO mice at as early as 3 weeks of age, and with aging these lesions were accompanied by gastritis cystica profunda (GCP). Cxcl1, Cxcl5, Ccl2, and Cxcr2 transcripts in gastric mucosa of 5-week-old A4gnt/Chst4 DKO mice exhibiting both hyperplasia and severe erosion were significantly upregulated relative to age-matched A4gnt KO mice, which showed hyperplasia alone. However, upregulation of these genes disappeared in 50-week-old A4gnt/Chst4 DKO mice exhibiting high-grade dysplasia/adenocarcinoma and GCP. Moreover, Cxcl1 and Cxcr2 were downregulated in A4gnt/Chst4 DKO mice relative to age-matched A4gnt KO mice exhibiting adenocarcinoma alone. These combined results indicate that the presence of sulfomucins prevents severe gastric erosion followed by GCP in A4gnt KO mice by transiently regulating a set of inflammation-related genes, Cxcl1, Cxcl5, Ccl2, and Cxcr2 at 5 weeks of age, although sulfomucins were not directly associated with gastric cancer development.

Induction of peripheral lymph node addressin in human nasal mucosa with eosinophilic chronic rhinosinusitis

Eosinophilic chronic rhinosinusitis (ECRS) is characterised by formation of nasal polyps with prominent eosinophilic infiltration; however, how eosinophils are recruited in this pathological setting remains unclear. In the present study, we carried out quantitative immunohistochemical analysis of nasal polyps associated with ECRS (n=30) and non-ECRS (n=30) to evaluate expression of an L-selectin ligand peripheral lymph node addressin (PNAd) on vascular endothelial cells. We found that PNAd was induced primarily on the luminal surface of venular vessels present in nasal mucosa in both ECRS and non-ECRS, while the number of PNAd-expressing vessels in ECRS significantly exceeded that seen in non-ECRS. Moreover, the number of eosinophils attached to the luminal surface of PNAd-expressing vessels in ECRS was significantly greater than that in non-ECRS, while the number of neutrophils and lymphocytes attached did not differ significantly between conditions. Furthermore, eosinophils, which express cell surface L-selectin, adhered to PNAd-expressing Chinese hamster ovary (CHO) cells in a calcium-dependent manner, and that adhesion was significantly inhibited by pretreatment of eosinophils with DREG-56, an anti-human L-selectin monoclonal antibody. These findings combined suggest that interaction between L-selectin and PNAd plays at least a partial role in eosinophil recruitment in human nasal mucosa with ECRS.

Role of MAdCAM-1-Expressing High Endothelial Venule-Like Vessels in Colitis Induced in Mice Lacking Sulfotransferases Catalyzing L-Selectin Ligand Biosynthesis

Ulcerative colitis (UC) is a chronic inflammatory disease histologically characterized by diffuse mononuclear cell infiltrates in colonic mucosa. These inflammatory cells are considered to be recruited via high endothelial venule (HEV)-like vessels displaying mucosal addressin cell adhesion molecule 1 (MAdCAM-1), the ligand for α4β7 integrin, and/or peripheral lymph node addressin (PNAd), an L-selectin ligand. 6- O-sulfation of N-acetylglucosamine in the carbohydrate moiety of PNAd is catalyzed exclusively by N-acetylglucosamine-6- O-sulfotransferase 1 (GlcNAc6ST-1) and GlcNAc6ST-2. To determine the role of 6- O-sulfation of N-acetylglucosamine on HEV-like vessels in UC, we used a chronic dextran sulfate sodium-induced colitis model using mice deficient in both GlcNAc6ST-1 and GlcNAc6ST-2. We found that more inflammatory cells, with expression of tumor necrosis factor α, were infiltrated in double knockout mouse colitis compared with that in wild-type mice. Moreover, the number of MAdCAM-1-positive vessels was increased in double knockout mouse colitis, and these vessels were bound by E-selectin•IgM chimeras that bind to unsulfated sialyl Lewis X (sLeX). These findings suggest that interactions between MAdCAM-1 and α4β7 integrin and/or unsulfated sLeX and L-selectin may become a dominant mechanism for inflammatory cell recruitment in the absence of 6-sulfo sLeX and contribute to more severe colitis phenotypes seen in double knockout mice.

Lymphotoxin β receptor signalling executes Helicobacter pylori-driven gastric inflammation in a T4SS-dependent manner

OBJECTIVE

Lymphotoxin β receptor (LTβR) signalling has been implicated in inflammation-associated tumour development in different tissues. We have analysed the role of LTβR and alternative NF-κB signalling in Helicobacter pylori-mediated gastric inflammation and pathology.

DESIGN

We analysed several ligands and receptors of the alternative NF-κB pathway, RelB, p52 nuclear translocation and target genes in tissue samples of H. pylori-infected patients with different degrees of gastritis or early gastric tumours by in situ hybridisation, immunohistochemistry, Western blot and real-time PCR analyses. Molecular mechanisms involved in LTβR activation by H. pylori were assessed in vitro using human gastric cancer cell lines and distinct H. pylori isolates. The effects of blocking or agonistically activating LTβR on gastric pathology during challenge with a human pathogenic H. pylori strain were studied in a mouse model.

RESULTS

Among the tested candidates, LT was significantly increased and activated alternative NF-κB signalling was observed in the gastric mucosa of H. pylori-infected patients. H. pyloriinduced LTβR-ligand expression in a type IV secretion system-dependent but CagA-independent manner, resulting in activation of the alternative NF-κB pathway, which was further enhanced by blocking canonical NF-κB during infection. Blocking LTβR signalling in vivo suppressed H. pylori-driven gastritis, whereas LTβR activation in gastric epithelial cells of infected mice induced a broadened pro-inflammatory chemokine milieu, resulting in exacerbated pathology.

CONCLUSIONS

LTβR-triggered activation of alternative NF-κB signalling in gastric epithelial cells executes H. pylori-induced chronic gastritis, representing a novel target to restrict gastric inflammation and pathology elicited by H. pylori, while exclusively targeting canonical NF-κB may aggravate pathology by enhancing the alternative pathway.

Role of sialyl 6-sulfo Lewis X in antitumor immunity against oral squamous cell carcinoma

BACKGROUND

Tumor-infiltrating lymphocytes (TILs) reportedly play a pivotal role in antitumor immunity against oral squamous cell carcinoma (OSCC); however, mechanisms governing TIL recruitment to OSCC tissues remain to be clarified. This study was undertaken to assess a potential association between TILs and high endothelial venule (HEV)-like vessels that express sialyl 6-sulfo Lewis X (LeX).

METHODS

OSCC tissue sections (n=41) were subjected to immunohistochemistry for sialyl 6-sulfo LeX and CD34 to allow quantitation of HEV-like vessels. Triple immunohistochemistry for sialyl 6-sulfo LeX and either CD3 and CD20 or CD4 and CD8 was conducted to determine which lymphocyte subset is more closely associated with HEV-like vessels.

RESULTS

HEV-like vessels expressing sialyl 6-sulfo LeX were detected in 27 of 41 (65.9%) OSCC cases, and these vessels were more frequently found in early disease (T1/T2 stages) compared with advanced (T3/T4) stages. The number of T cells attached to the inner surface of these HEV-like vessels was significantly greater than that of B cells, while the number of CD4⁺ helper T cells and CD8⁺ cytotoxic T cells did not differ significantly. Interestingly, sialyl 6-sulfo LeX was also expressed on the membrane of a fraction of OSCC cells, and CD8⁺ cytotoxic T cells were almost exclusively found attached to these carcinoma cells.

CONCLUSIONS

Sialyl 6-sulfo LeX is displayed not only on HEV-like vessels but also on OSCC cells and may potentially function in antitumor immunity against OSCC.

Appearance of High Endothelial Venule-Like Vessels in Benign Prostatic Hyperplasia is Associated With Lower Urinary tract Symptoms

BACKGROUND

Chronic prostatic inflammation is implicated in the pathogenesis of benign prostatic hyperplasia (BPH)-associated lower urinary tract symptoms (LUTS). Previous studies evaluated the degree of chronic prostatic inflammation based on histological scores, which may contain subjective factors. We previously demonstrated that the number of high endothelial venule (HEV)-like vessels correlates positively with the magnitude of inflammation in chronic inflammatory gastrointestinal diseases. Here, we evaluated the degree of BPH-associated chronic prostate inflammation based on appearance of HEV-like vessels and determined whether the extent of inflammation correlated with LUTS severity, as evaluated by a urodynamic study.

METHODS

Eighty-six BPH tissue specimens derived from patients who had undergone urodynamic analysis were immunostained for CD34 and MECA-79 to determine HEV-like vessel number. Triple immunohistochemistry for either CD3 and CD20 or CD4 and CD8, together with MECA-79, was conducted to identify lymphocyte subsets associated with HEV-like vessels. We also determined whether the magnitude of chronic prostatic inflammation, as assessed by HEV-like vessel number, correlated with the degree of LUTS.

RESULTS

HEV-like vessels were induced in lymphoid aggregates seen frequently in BPH. The number of HEV-like vessels positively correlated not only with the magnitude of chronic prostatic inflammation but also with the degree of LUTS, particularly with symptoms associated with voiding function, which was measured objectively in a pressure flow study.

CONCLUSIONS

Chronic prostate inflammation may promote BPH and resulting voiding dysfunction. Assessment of the number of HEV-like vessels could be a surrogate for identifying the degree of chronic prostatic inflammation. Prostate 77:794-802, 2017. © 2017 Wiley Periodicals, Inc.

TNFΔARE Mice Display Abnormal Lymphatics and Develop Tertiary Lymphoid Organs in the Mesentery

Chronic inflammatory diseases are associated with a persistent and enhanced response to environmental antigens. As an adaptive response to this exaggerated immune state, affected tissue typically develops tertiary lymphoid organs. Studies of Crohn disease (CD), a chronic inflammatory disease of the intestinal tract, report tertiary lymphoid organs present within the mucosal wall, along with other lymphatic diseases, such as lymphangiogenesis and obstructed lymphatic vessels. These observations suggest that downstream mesenteric lymphatic vessels and lymph drainage into mesenteric lymph nodes may be compromised. However, information is lacking on the morphologic features and functional status of mesenteric lymphatics in CD. Using confocal imaging, PCR, flow cytometry, and functional strategies, we addressed these questions in the established TNFΔARE mouse model of CD and found that this mouse model had many lymphatic abnormalities reminiscent of human CD. These abnormalities include intestinal lymphangiectasia, mesenteric lymph node lymphadenopathy, and lymphangiogenesis in both the mesentery and mucosa. Critically, TNFΔARE mice also present mesenteric tertiary lymphoid organs and have altered lymphatic transport of dendritic cells to mesenteric lymph nodes, two features likely to actively modulate immunity. Our findings provide key insights into lymphatic remodeling in the TNFΔARE mouse model. They shed light on the involvement of these lymphatic changes in immune dysfunctions observed in CD and suggest the lymphatic system as new target for therapeutic options.

Apical membrane expression of distinct sulfated glycans represents a novel marker of cholangiolocellular carcinoma

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver neoplasm, followed by hepatocellular carcinoma. ICC can be further subclassified as (i) perihilar and (ii) peripheral types, the latter histologically resembling small-sized intrahepatic bile ducts, such as interlobular bile ducts, cholangioles/ductules and the canals of Hering. Cholangiolocellular carcinoma (CoCC), now classified by the World Health Organization as a subtype of combined hepatocellular-cholangiocarcinoma, is currently regarded as a subtype of peripheral-type ICC. The present study was undertaken to determine whether sulfated glycans recognized by the MECA-79 monoclonal antibody could serve as a CoCC marker. Using immunohistochemistry, we show that MECA-79 sulfated glycans are preferentially expressed at the apical membrane of cholangiocytes found in small-sized intrahepatic bile ducts in normal liver and in canalicular structures formed in CoCC. We also report that apical membrane MECA-79 sulfated glycan expression colocalizes with that of mucin 1 (MUC1) core proteins. We also present immunoblotting of Chinese hamster ovary cells overexpressing FLAG-tagged MUC1 to show that MUC1 serves as a MECA-79 scaffold. Furthermore, we report that SSP-25 human ICC cells overexpressing N-acetylglucosamine-6-O-sulfotransferase 2 (GlcNAc6ST-2), but not GlcNAc6ST-1, exhibit membrane expression of MECA-79 sulfated glycans, suggesting that GlcNAc6ST-2 catalyzes MECA-79 epitope biosynthesis in cholangiocytes. Moreover, both wild-type and GlcNAc6ST-1 knockout mice exhibit apical membrane MECA-79 expression in small-sized intrahepatic bile ducts, namely interlobular bile ducts, whereas MECA-79 expression was completely absent in comparable tissues from GlcNAc6ST-1 and GlcNAc6ST-2 double knockout mice. These data collectively indicate that apical membrane localization of MUC1 proteins decorated with GlcNAc6ST-2-dependent MECA-79 sulfated glycans may mark cholangiocytes with cholangiolar/ductular differentiation and could serve as a useful CoCC marker.

High endothelial venule-like vessels and lymphocyte recruitment in diffuse sclerosing variant of papillary thyroid carcinoma

Diffuse sclerosing variant of papillary thyroid carcinoma (DSPTC) is a rare subtype of papillary thyroid carcinoma with a high incidence of lymph node metastasis. One of its characteristic histological features is the presence of dense lymphocyte infiltrates; however, how these lymphocytes are recruited in this pathological setting remains unclear. Here, we analysed 17 DSPTC cases immunohistologically for cell adhesion molecules expressed on endothelial cells. We found that venules morphologically similar to high endothelial venules (HEVs) in secondary lymphoid organs were induced in lymphoid aggregates in DSPTC, and such HEV-like vessels expressed 6-sulfo sialyl Lewis X (sLeX) glycans as well as intercellular adhesion molecule 1 (ICAM-1). Triple immunohistochemistry revealed that CD8⁺ cytotoxic T cells were the major lymphocyte subset attached to the luminal surface of HEV-like vessels. sLeX-type glycans were also expressed on DSPTC carcinoma cells, which in binding assays were decorated with E-selectin•IgM chimaeras calcium-dependently. These findings collectively suggest that 6-sulfo sLeX glycans, together with ICAM-1, on HEV-like vessels may function to recruit CD8⁺ cytotoxic T cells in DSPTC. Additionally, sLeX-type glycans on carcinoma cells might partly contribute to highly metastatic properties of DSPTC through interaction with E-selectin expressed on endothelial cells.

Ectopic Tertiary Lymphoid Tissue in Inflammatory Bowel Disease: Protective or Provocateur?

Organized lymphoid tissues like the thymus first appeared in jawed vertebrates around 500 million years ago and have evolved to equip the host with a network of specialized sites, strategically located to orchestrate strict immune-surveillance and efficient immune responses autonomously. The gut-associated lymphoid tissues maintain a mostly tolerant environment to dampen our responses to daily dietary and microbial products in the intestine. However, when this homeostasis is perturbed by chronic inflammation, the intestine is able to develop florid organized tertiary lymphoid tissues (TLT), which heralds the onset of regional immune dysregulation. While TLT are a pathologic hallmark of Crohn's disease (CD), their role in the overall process remains largely enigmatic. A critical question remains; are intestinal TLT generated by the immune infiltrated intestine to modulate immune responses and rebuild tolerance to the microbiota or are they playing a more sinister role by generating dysregulated responses that perpetuate disease? Herein, we discuss the main theories of intestinal TLT neogenesis and focus on the most recent findings that open new perspectives to their role in inflammatory bowel disease.

Adhesion Molecules: Master Controllers of the Circulatory System

This manuscript will review our current understanding of cellular adhesion molecules (CAMs) relevant to the circulatory system, their physiological role in control of vascular homeostasis, innate and adaptive immune responses, and their importance in pathophysiological (disease) processes such as acute lung injury, atherosclerosis, and pulmonary hypertension. This is a complex and rapidly changing area of research that is incompletely understood. By design, we will begin with a brief overview of the structure and classification of the major groups of adhesion molecules and their physiological functions including cellular adhesion and signaling. The role of specific CAMs in the process of platelet aggregation and hemostasis and leukocyte adhesion and transendothelial migration will be reviewed as examples of the complex and cooperative interplay between CAMs during physiological and pathophysiological processes. The role of the endothelial glycocalyx and the glycobiology of this complex system related to inflammatory states such as sepsis will be reviewed. We will then focus on the role of adhesion molecules in the pathogenesis of specific disease processes involving the lungs and cardiovascular system. The potential of targeting adhesion molecules in the treatment of immune and inflammatory diseases will be highlighted in the relevant sections throughout the manuscript.

Histomolecular Structural Aspects of High Endothelial Vessels in Lymph Node and Its Significance in Oral Cancer and Metastasis

Molecular cancer research studies focus on identifying diagnostic, screening, and metastatic indicators, and monitoring therapeutic responses. Migration of tumor cells and lymphocytes are important aspects in metastasis. High endothelial vessels are specialized histological structures identified in the blood vessels in lymphoid organs, which allow the migration of lymphocytes. In the recent decades, the role of high endothelial vessels is being addressed in cancer metastatic research. This review article is to highlight the histological and molecular structural aspects of high endothelial venules (HEVs) in the lymph node, and to demonstrate the role of HEVs in oral cancer metastasis, specifically oral and pharyngeal squamous cell carcinoma. The literature for the present paper were searched from the data sources such as Medline/PubMed, CINAHL plus, and gray literature sources from inception to May 2015. Searches were conducted using both free texts and medical subject headings related to the title of the present paper. Only the full text manuscripts of the search results that support the objective(s) of the paper and papers written in English were included. HEVs are unique structures that are identified in the lymphocytes and primarily assist in the lymphocytic migration from the blood stream into the lymph node. Understanding the histomolecular characteristics of HEV will allow researchers to develop novel therapeutic approaches in cancer tissues.

A potential role for 6-sulfo sialyl Lewis X in metastasis of bladder urothelial carcinoma

OBJECTIVES

It is widely accepted that sialyl Lewis X (sLeX) and sialyl Lewis A (sLeA, also known as CA 19-9) glycans expressed on cancer cells function in E-selectin-mediated metastasis. Recently, it was reported that 6-sulfo sLeX glycans detected by the MECA-79 monoclonal antibody are expressed in roughly a quarter of gastric adenocarcinoma cases, and that these cases show a poorer prognosis than MECA-79-negative cases do. The present study was undertaken to assess expression of 6-sulfo sLeX glycans in bladder urothelial carcinoma and evaluate potential clinical implications.

MATERIALS AND METHODS

We analyzed 78 specimens representing bladder urothelial carcinoma, as well as 4 bladder urothelial carcinoma cell lines, by immunostaining with a battery of anticarbohydrate antibodies. We also undertook an E-selectin·IgM chimera binding assay to assess E-selectin binding to 6-sulfo sLeX expressed on bladder urothelial carcinoma cells and performed reverse transcription polymerase chain reaction and complementary DNA transfection to determine which N-acetylglucosamine-6-O-sulfotransferases function in 6-sulfo sLeX biosynthesis in those cells. Finally, we performed double-immunofluorescence staining for MECA-79 and either CD3 or CD8 to evaluate potential association between high endothelial venule (HEV)-like vessels and tumor-infiltrating T lymphocytes.

RESULTS

6-Sulfo sLeX glycans were expressed in ~20% of bladder urothelial carcinoma cases, particularly in plasmacytoid and micropapillary variants. Positive cells were also bound by E-selectin·IgM chimeras in a calcium-dependent manner. Transcripts encoding N-acetylglucosamine-6-O-sulfotransferase-2 were detected preferentially in HT-1197 bladder urothelial carcinoma cells expressing 6-sulfo sLeX, and transfection of the enzyme complementary DNA into HT-1376 cells, which do not express 6-sulfo sLeX glycans, resulted in cell surface expression of 6-sulfo sLeX. Furthermore, 6-sulfo sLeX glycans were expressed in HEV-like vessels induced in and around lymphocyte aggregates formed near carcinoma cell nests. These HEV-like vessel-associated tumor-infiltrating lymphocytes were composed primarily of CD3(+) T cells, with a fraction of CD8(+) cytotoxic T cells.

CONCLUSIONS

Our findings indicate that 6-sulfo sLeX glycans likely play 2 roles in bladder urothelial carcinoma progression: one in lymphocyte recruitment to enhance antitumor immune responses, and the other in E-selectin-mediated tumor cell adhesion to vascular endothelial cells, which is potentially associated with metastasis.

Atomic force microscopy measurements reveal multiple bonds between Helicobacter pylori blood group antigen binding adhesin and Lewis b ligand

The strength of binding between the Helicobacter pylori blood group antigen-binding adhesin (BabA) and its cognate glycan receptor, the Lewis b blood group antigen (Le(b)), was measured by means of atomic force microscopy. High-resolution measurements of rupture forces between single receptor-ligand pairs were performed between the purified BabA and immobilized Le(b) structures on self-assembled monolayers. Dynamic force spectroscopy revealed two similar but statistically different bond populations. These findings suggest that the BabA may form different adhesive attachments to the gastric mucosa in ways that enhance the efficiency and stability of bacterial adhesion.

Superficially located enlarged lymphoid follicles characterise nodular gastritis

Nodular gastritis is a form of chronic Helicobacter pylori gastritis affecting the gastric antrum and characterised endoscopically by the presence of small nodular lesions resembling gooseflesh. It is generally accepted that hyperplasia of lymphoid follicles histologically characterises nodular gastritis; however, quantitative analysis in support of this hypothesis has not been reported. Our goal was to determine whether nodular gastritis is characterised by lymphoid follicle hyperplasia.The number, size, and location of lymphoid follicles in nodular gastritis were determined and those properties compared to samples of atrophic gastritis. The percentages of high endothelial venule (HEV)-like vessels were also evaluated.The number of lymphoid follicles was comparable between nodular and atrophic gastritis; however, follicle size in nodular gastritis was significantly greater than that seen in atrophic gastritis. Moreover, lymphoid follicles in nodular gastritis were positioned more superficially than were those in atrophic gastritis. The percentage of MECA-79 HEV-like vessels was greater in areas with gooseflesh-like lesions in nodular versus atrophic gastritis.Superficially located hyperplastic lymphoid follicles characterise nodular gastritis, and these follicles correspond to gooseflesh-like nodular lesions observed endoscopically. These observations suggest that MECA-79 HEV-like vessels could play at least a partial role in the pathogenesis of nodular gastritis.

Understanding high endothelial venules: Lessons for cancer immunology

High endothelial venules (HEVs) are blood vessels especially adapted for lymphocyte trafficking which are normally found in secondary lymphoid organs such as lymph nodes (LN) and Peyer's patches. It has long been known that HEVs develop in non-lymphoid organs during chronic inflammation driven by autoimmunity, infection or allografts. More recently, HEVs have been observed in solid, vascularized tumors and their presence correlated with reduced tumor size and improved patient outcome. It is proposed that newly formed HEV promote antitumor immunity by recruiting naive lymphocytes into the tumor, thus allowing the local generation of cancerous tissue-destroying lymphocytes. Understanding how HEVs develop and function are therefore important to unravel their role in human cancers. In LN, HEVs develop during embryonic and early post-natal life and are actively maintained by the LN microenvironment. Systemic blockade of lymphotoxin-β receptor leads to HEV de-differentiation, but the LN components that induce HEV differentiation have remained elusive. Recent elegant studies using gene-targeted mice have demonstrated clearly that triggering the lymphotoxin-β receptor in endothelial cells (EC) induces the differentiation of HEV and that CD11c⁺ dendritic cells play a crucial role in this process. It will be important to determine whether lymphotoxin-β receptor-dependent signaling in EC drives the development of HEV during tumorigenesis and which cells have HEV-inducer properties. This may reveal therapeutic approaches to promote HEV neogenesis and determine the impact of newly formed HEV on tumor immunity.

Novel Antibodies Reactive with Sialyl Lewis X in Both Humans and Mice Define Its Critical Role in Leukocyte Trafficking and Contact Hypersensitivity Responses

Sialyl Lewis X (sLe(x)) antigen functions as a common carbohydrate determinant recognized by all three members of the selectin family. However, its expression and function in mice remain undefined due to the poor reactivity of conventional anti-sLe(x) monoclonal antibodies (mAbs) with mouse tissues. Here, we developed novel anti-sLe(x) mAbs, termed F1 and F2, which react well with both human and mouse sLe(x), by immunizing fucosyltransferase (FucT)-IV and FucT-VII doubly deficient mice with 6-sulfo-sLe(x)-expressing cells transiently transfected with an expression vector encoding CMP-N-acetylneuraminic acid hydroxylase. F1 and F2 specifically bound both the N-acetyl and the N-glycolyl forms of sLe(x) as well as 6-sulfo-sLe(x), a major ligand for L-selectin expressed in high endothelial venules, and efficiently blocked physiological lymphocyte homing to lymph nodes in mice. Importantly, both of the mAbs inhibited contact hypersensitivity responses not only when administered in the L-selectin-dependent sensitization phase but also when administered in the elicitation phase in mice. When administered in the latter phase, F1 and F2 efficiently blocked rolling of mouse leukocytes along blood vessels expressing P- and E-selectin in the auricular skin in vivo. Consistent with these findings, the mAbs blocked P- and E-selectin-dependent leukocyte rolling in a flow chamber assay. Taken together, these results indicate that novel anti-sLe(x) mAbs reactive with both human and mouse tissues, with the blocking ability against leukocyte trafficking mediated by all three selectins, have been established. These mAbs should be useful in determining the role of sLe(x) antigen under physiological and pathological conditions.

Lymphocyte 'homing' and chronic inflammation

Chronic inflammation is a response to prolonged exposure to injurious stimuli that harm and destroy tissues and promote lymphocyte infiltration into inflamed sites. Following progressive accumulation of lymphocytes, the histology of inflamed tissue begins to resemble that of peripheral lymphoid organs, which can be referred to as lymphoid neogenesis or formation of tertiary lymphoid tissues. Lymphocyte recruitment to inflamed tissues is also reminiscent of lymphocyte homing to peripheral lymphoid organs. In the latter, under physiological conditions, homing receptors expressed on lymphocytes adhere to vascular addressin expressed on high endothelial venules (HEVs), initiating a lymphocyte migration process composed of sequential adhesive interactions. Intriguingly, in chronic inflammation, HEV-like vessels are induced de novo, despite the fact that the inflamed site is not originally lymphoid tissue, and these vessels contribute to lymphocyte recruitment in a manner similar to physiological lymphocyte homing. In this review, we first describe physiological lymphocyte homing mechanisms focusing on vascular addressins. We then describe HEV-like vessel-mediated pathogenesis seen in various chronic inflammatory disorders such as Helicobacter pylori gastritis, inflammatory bowel disease (IBD), autoimmune pancreatitis and sclerosing sialadenitis, as well as chronic inflammatory cell neoplasm MALT lymphoma, with reference to our work and that of others.

Helicobacter pylori interferes with leukocyte migration via the outer membrane protein HopQ and via CagA translocation

The human gastric pathogen Helicobacter pylori is a paradigm for chronic bacterial infections. Persistent colonization of the stomach mucosa is facilitated by several mechanisms of immune evasion and immune modulation, such as avoidance of Toll-like receptor recognition or skewing of effector T cell responses. Interactions of H. pylori with different immune cells have been described with respect to immune cell activation, cytokine release, or oxidative burst induction. We show here that H. pylori infection of human granulocytes, or of HL-60 cells differentiated to a granulocyte-like phenotype (dHL-60 cells) results in inhibition of cell migration under different conditions. Migration of dHL-60 cells in a three-dimensional collagen gel was found to be inhibited independently of the cag pathogenicity island, whereas migration inhibition in an under agarose assay was dependent on the cag pathogenicity island, on its effector protein CagA, and on the outer membrane protein HopQ. CagA translocation into leukocytes is accompanied by its tyrosine phosphorylation and by proteolytic processing into an N-terminal 100 kDa and a C-terminal 35 kDa fragment at a distinct cleavage site. By using complemented H. pylori strains producing either phosphorylation-resistant or cleavage-resistant CagA variants, we show that CagA tyrosine phosphorylation is required for migration inhibition, but CagA processing is not. Our results suggest that direct contact of H. pylori with immune cells subverts not only their activation characteristics, but also their migratory behaviour.

Artery Tertiary Lymphoid Organs Contribute to Innate and Adaptive Immune Responses in Advanced Mouse Atherosclerosis

Tertiary lymphoid organs emerge in tissues in response to nonresolving inflammation. Recent research characterized artery tertiary lymphoid organs in the aorta adventitia of aged apolipoprotein E–deficient mice. The atherosclerosis-associated lymphocyte aggregates are organized into distinct compartments, including separate T-cell areas harboring conventional, monocyte-derived, lymphoid, and plasmacytoid dendritic cells, as well as activated T-cell effectors and memory cells; B-cell follicles containing follicular dendritic cells in activated germinal centers; and peripheral niches of plasma cells. Artery tertiary lymphoid organs show marked neoangiogenesis, aberrant lymphangiogenesis, and extensive induction of high endothelial venules. Moreover, newly formed lymph node–like conduits connect the external lamina with high endothelial venules in T-cell areas and also extend into germinal centers. Mouse artery tertiary lymphoid organs recruit large numbers of naïve T cells and harbor lymphocyte subsets with opposing activities, including CD4 + and CD8 + effector and memory T cells, natural and induced CD4 + regulatory T cells, and memory B cells at different stages of differentiation. These data suggest that artery tertiary lymphoid organs participate in primary immune responses and organize T- and B-cell autoimmune responses in advanced atherosclerosis. In this review, we discuss the novel concept that pro- and antiatherogenic immune responses toward unknown arterial wall–derived autoantigens may be organized by artery tertiary lymphoid organs and that disruption of the balance between pro- and antiatherogenic immune cell subsets may trigger clinically overt atherosclerosis.

High endothelial venule-like vessels and lymphocyte recruitment in testicular seminoma

Seminoma, the most common testicular malignant neoplasm, originates from germ cells and is characterized by the presence of numerous tumour-infiltrating lymphocytes (TILs). Although it is widely accepted that TILs function in surveillance and cytotoxicity in various tumours including seminoma, detailed mechanisms governing TIL recruitment are not fully understood. It has been shown that high endothelial venule (HEV)-like vessels are induced in inflamed and neoplastic tissues and contribute to lymphocyte recruitment in a manner similar to the way physiological lymphocyte homing occurs in secondary lymphoid organs. Here, we report that HEV-like vessels, which express MECA-79(+) 6-sulfo sialyl Lewis X-capped structures, are induced in TIL aggregates in seminoma, and that such vessels potentially recruit circulating lymphocytes, as an E-selectin•IgM chimera bound these vessels in a calcium-dependent manner. These HEV-like vessels express intercellular adhesion molecule 1 (ICAM-1), but not vascular cell adhesion molecule 1 (VCAM-1) or mucosal addressin cell adhesion molecule 1 (MAdCAM-1), which likely contributes to lymphocyte firm attachment. We also found that the number of T cells attached to the luminal surface of HEV-like vessels was greater than the number of B cells (p < 0.0001). Interestingly, while CD8(+) cytotoxic T lymphocytes (CTLs) attached to the lumen of HEV-like vessels were scarcely detected, significant numbers of proliferative CTLs were observed outside vessels. These histological findings strongly suggest that TILs, particularly T cells, are recruited to seminoma tissues via HEV-like vessels, and that tumour-infiltrating CTLs then undergo proliferation after transmigration through HEV-like vessels in testicular seminoma.

Dynamic changes in endothelial cell adhesion molecule nepmucin/CD300LG expression under physiological and pathological conditions

Vascular endothelial cells often change their phenotype to adapt to their local microenvironment. Here we report that the vascular endothelial adhesion molecule nepmucin/CD300LG, which is implicated in lymphocyte binding and transmigration, shows unique expression patterns in the microvascular endothelial cells of different tissues. Under physiological conditions, nepmucin/CD300LG was constitutively and selectively expressed at the luminal surface of the small arterioles, venules, and capillaries of most tissues, but it was only weakly expressed in the microvessels of the splenic red pulp and thymic medulla. Furthermore, it was barely detectable in immunologically privileged sites such as the brain, testis, and uterus. The nepmucin/CD300LG expression rapidly decreased in lymph nodes receiving acute inflammatory signals, and this loss was mediated at least in part by TNF-α. It was also down-regulated in tumors and tumor-draining lymph nodes, indicating that nepmucin/CD300LG expression is negatively regulated by locally produced signals under these circumstances. In contrast, nepmucin/CD300LG was induced in the high endothelial venule-like blood vessels of chronically inflamed pancreatic islets in an animal model of non-obese diabetes. Interestingly, the activated CD4⁺ T cells infiltrating the inflamed pancreas expressed high levels of the nepmucin/CD300LG ligand(s), supporting the idea that nepmucin/CD300LG and its ligand interactions are locally involved in pathological T cell trafficking. Taken together, these observations indicate that the nepmucin/CD300LG expression in microvascular endothelial cells is influenced by factor(s) that are locally produced in tissues, and that its expression is closely correlated with the level of leukocyte infiltration in certain tissues.

Alterations of high endothelial venules in primary and metastatic tumors are correlated with lymph node metastasis of oral and pharyngeal carcinoma

High endothelial venules (HEVs) are special blood vessels in the paracortical region of lymph nodes (LNs) and govern lymphocyte recruitment. LN metastasis has similarity to circulating lymphocytes homing to LNs, but the role of HEVs in the progression of oral and pharyngeal squamous cell carcinoma (OPSCC) is unclear. In this study, we found that HEVs experienced a series of morphological and functional changes during OPSCC progression and were correlated with LN metastasis. In 9 cases of 73 metastatic LNs, tumor emboli were located adjacent to HEVs or just out of the vessels but not lymphatic channels. Gap junctions of tumor cells close to HEVs decreased or disappeared, and gaps were left at contact points where tumor cells attached to the HEVs. Moreover, the proliferation rate of endothelial cells of HEVs was the highest in metastatic LNs. Finally, L-selectin was detected in both primary and metastatic tumors, and it facilitated tumor cells adhering to LNs. In conclusion, our findings suggest that remodeled HEVs are correlated with LN metastasis of OPSCC and play important role in this process by preparing premetastatic soil for cancer cell metastasis.

Helicobacter pylori cholesteryl α-glucosides contribute to its pathogenicity and immune response by natural killer T cells

Approximately 10–15% of individuals infected with Helicobacter pylori will develop ulcer disease (gastric or duodenal ulcer), while most people infected with H. pylori will be asymptomatic. The majority of infected individuals remain asymptomatic partly due to the inhibition of synthesis of cholesteryl α-glucosides in H. pylori cell wall by α1,4-GlcNAc-capped mucin O-glycans, which are expressed in the deeper portion of gastric mucosa. However, it has not been determined how cholesteryl α-glucosyltransferase (αCgT), which forms cholesteryl α-glucosides, functions in the pathogenesis of H. pylori infection. Here, we show that the activity of αCgT from H. pylori clinical isolates is highly correlated with the degree of gastric atrophy. We investigated the role of cholesteryl α-glucosides in various aspects of the immune response. Phagocytosis and activation of dendritic cells were observed at similar degrees in the presence of wild-type H. pylori or variants harboring mutant forms of αCgT showing a range of enzymatic activity. However, cholesteryl α-glucosides were recognized by invariant natural killer T (iNKT) cells, eliciting an immune response in vitro and in vivo. Following inoculation of H. pylori harboring highly active αCgT into iNKT cell-deficient (Jα18^−/−) or wild-type mice, bacterial recovery significantly increased in Jα18^−/− compared to wild-type mice. Moreover, cytokine production characteristic of Th1 and Th2 cells dramatically decreased in Jα18^−/− compared to wild-type mice. These findings demonstrate that cholesteryl α-glucosides play critical roles in H. pylori-mediated gastric inflammation and precancerous atrophic gastritis.

High levels of FOXP3⁺ regulatory T cells in gastric MALT lymphoma predict responsiveness to Helicobacter pylori eradication

BACKGROUND

Although Helicobacter pylori eradication is a first-line treatment of gastric MALT lymphoma, roughly 25% of patients do not respond to treatment. CD4⁺ FOXP3⁺ regulatory T (Treg) cells regulate immune responses in physiological conditions and various inflammatory conditions, including H. pylori-associated diseases. Our goal was to determine how Treg cells affect responsiveness to H. pylori eradication therapy.

MATERIALS AND METHODS

We performed dual immunohistochemistry for CD4 and FOXP3 to evaluate the prevalence of FOXP3⁺ Treg cells in the stomach of 63 patients with MALT lymphoma and 55 patients with chronic active gastritis. Receiver operating characteristic analysis was carried out to determine the best cut-off point in differentiating H. pylori eradication responders from nonresponders.

RESULTS

Both the FOXP3⁺/CD4⁺ cell ratio and the absolute number of FOXP3⁺ cells per high-power field in MALT lymphoma were significantly greater in H. pylori eradication responders compared with nonresponders, suggesting that Treg cells function in regression mechanisms of MALT lymphomas. Cut-off points with good sensitivities and specificities were obtained to predict eradication outcome.

CONCLUSIONS

A high number of Treg cells or a high ratio of Treg cells to the total number of CD4⁺ T cells in gastric MALT lymphoma could predict responsiveness to eradication therapy.

Lymphocyte recruitment via high endothelial venules in lymphoid stroma of Warthin's tumour

AIMS

Warthin's tumour is composed of bilayered oncocytic epithelium and organised lymphoid stroma, which resembles mucosa-associated lymphoid tissue (MALT); however, the histogenesis of the lymphoid stroma is not fully understood. We hypothesised that lymphocytes consisting of the stroma are recruited via high endothelial venules (HEVs) by the mechanism operating in normal lymphocyte homing in secondary lymphoid organs. The aim of this study was to determine immunohistochemically the molecules expressed on these HEVs.

METHODS

Tissue sections of Warthin's tumour (n = 10) were immunostained for vascular addressin-related antigens including peripheral lymph node addressin (PNAd) and mucosal addressin cell adhesion molecule 1 (MAdCAM-1). An L-selectin·IgM chimera in situ binding assay was also carried out. Triple immunostaining for PNAd, CD3, and CD20/CD79α was performed to determine which lymphocyte subsets are closely associated with these HEVs.

RESULTS

HEVs in the lymphoid stroma of Warthin's tumour express PNAd, which is detected by MECA-79 as well as recently developed monoclonal antibodies S1 and S2. These HEVs were bound by L-selectin·IgM chimeras in a calcium-dependent manner, and numbers of lymphocytes, particularly T cells, attached to these HEVs.

CONCLUSIONS

The lymphoid stroma of Warthin's tumour is most likely developed by lymphocytes recruited via HEVs.

A lympho-follicular microenvironment is required for pathological prion protein deposition in chronically inflamed tissues from scrapie-affected sheep

In sheep scrapie, pathological prion protein (PrP^Sc) deposition occurs in the lymphoreticular and central nervous systems. We investigated PrP^Sc distribution in scrapie-affected sheep showing simultaneous evidence of chronic lymphofollicular, lymphoproliferative/non-lymphofollicular, and/or granulomatous inflammations in their mammary gland, lung, and ileum. To do this, PrP^Sc detection was carried out via immunohistochemistry and Western Blotting techniques, as well as through inflammatory cell immunophenotyping. Expression studies of gene coding for biological factors modulating the host’s inflammatory response were also carried out. We demonstrated that ectopic PrP^Sc deposition occurs exclusively in the context of lymphofollicular inflammatory sites, inside newly formed and well-organized lymphoid follicles harboring follicular dendritic cells. On the contrary, no PrP^Sc deposition was detected in granulomas, even when they were closely located to newly formed lymphoid follicles. A significantly more consistent expression of lymphotoxin α and β mRNA was detected in lymphofollicular inflammation compared to the other two types, with lymphotoxin α and β signaling new lymphoid follicles’ formation and, likely, the occurrence of ectopic PrP^Sc deposition inside them. Our findings suggest that, in sheep co-affected by scrapie and chronic inflammatory conditions, only newly formed lymphoid follicles provide a suitable micro-environment that supports the scrapie agent’s replication in inflammatory sites, with an increased risk of prion shedding through body secretions/excretions.

Periductal induction of high endothelial venule-like vessels in type 1 autoimmune pancreatitis

OBJECTIVES

Type 1 autoimmune pancreatitis (AIP) is histologically characterized by dense lymphoplasmacytic infiltration and marked storiform fibrosis, manifestations associated with pancreatic ducts. Such periductal lymphocyte recruitment is thought to be elicited by dysregulation of mechanisms governing physiological lymphocyte homing. The present study was undertaken to determine whether vascular addressins including peripheral lymph node addressin and mucosal addressin cell adhesion molecule 1 (MAdCAM-1) play a role in type 1 AIP histogenesis.

METHODS

Tissue sections of type 1 AIP and tumor-associated non-AIP chronic pancreatitis, as well as normal pancreas, were subjected to immunohistochemical analysis using vascular addressin-related antibodies.

RESULTS

The number of periductal mouse endothelial cell antigen 79-positive high endothelial venule (HEV)-like vessels was increased in type 1 AIP relative to that seen in non-AIP chronic pancreatitis, whereas the number of MAdCAM-1-positive HEV-like vessels did not differ between the 2 conditions. Mouse endothelial cell antigen 79 antigens are expressed on duct-forming epithelial cells not only in pancreas but also in salivary glands, which often harbor extrapancreatic lesions in type 1 AIP.

CONCLUSIONS

Type 1 AIP can be characterized by periductal induction of MECA-79-positive HEV-like vessels. MECA-79-positive 6-sulfo sialyl Lewis X-related carbohydrate antigens expressed on duct-forming epithelial cells could be associated with type 1 AIP pathogenesis.

Expression of long-form N-acetylglucosamine-6-O-sulfotransferase 1 in human high endothelial venules

Two members of the N-acetylglucosamine-6-O-sulfotransferase (GlcNAc6ST) family, GlcNAc6ST-1 and GlcNAc6ST-2, function in the biosynthesis of 6-sulfo sialyl Lewis X-capped glycoproteins expressed on high endothelial venules (HEVs) in secondary lymphoid organs. Thus, both enzymes play a critical role in L-selectin-expressing lymphocyte homing. Human GlcNAc6ST-1 is encoded by a 1593-bp open reading frame exhibiting two 5' in-frame methionine codons spaced 141 bp apart. Both resemble the consensus sequence for translation initiation. Thus, it has been hypothesized that both long and short forms of GlcNAc6ST-1 may be present, although endogenous expression of either form has not been confirmed in humans. Here, the authors developed an antibody recognizing amino acid residues between the first two human GlcNAc6ST-1 methionines. This antibody specifically recognizes the long form of the enzyme, a finding validated by Western blot analysis and immunofluorescence cytochemistry of HeLa cells misexpressing long and/or short forms of human GlcNAc6ST-1. Using this antibody, the authors carried out immunofluorescence histochemistry of human lymph node tissue sections and found endogenous expression of the long form of the enzyme in human tissue, predominantly in the trans-Golgi network of endothelial cells that form HEVs.

Human solid tumors contain high endothelial venules: association with T- and B-lymphocyte infiltration and favorable prognosis in breast cancer

The mechanisms governing infiltration of lymphocytes into tumors remain poorly characterized, in spite of the critical impact of these cells on patient prognosis and therapeutic responses. High endothelial venules (HEV) are blood vessels found in lymphoid tissues, specialized in lymphocyte recruitment, but their implications in human cancer are unknown. In this article, we report the presence of MECA 79(+) blood vessels displaying all the phenotypic characteristics of HEVs in most of the 319 human primary solid tumors, including melanomas, breast, ovarian, colon, and lung carcinomas, analyzed. Tumor HEVs were specifically located within lymphocyte-rich areas, and their density within the tumor stroma was a strong predictor of infiltration by CD3(+) and CD8(+) T cells as well as B cells. Large-scale flow cytometric and quantitative reverse transcriptase-PCR analyses in freshly operated breast tumors revealed that high densities of tumor HEVs correlated with increased naive, central memory and activated effector memory T-cell infiltration and upregulation of genes related to T-helper 1 adaptive immunity and T-cell cytotoxicity. Finally, in a retrospective cohort of 146 invasive breast cancer patients, we found that high densities of tumor HEVs independently conferred a lower risk of relapse and significantly correlated with longer metastasis-free, disease-free, and overall survival rates. Together, our findings suggest that tumor HEVs function as major gateways for lymphocyte infiltration into human tumors, and may represent attractive targets for cancer diagnosis and therapy.

Reduced glycosylation of α-dystroglycans on carcinoma cells contributes to formation of highly infiltrative histological patterns in prostate cancer

BACKGROUND

α-Dystroglycan (DG) carries glycan chains that bind to laminin and thus function in homeostasis of not only skeletal muscle but also of various epithelial cells. Loss of glycosylation has been suggested to play important roles in tumor development, particularly in detachment and migration of carcinoma cells. We previously reported that glycosylation of α-DG, but not levels of α-DG core protein itself, is reduced in prostate carcinoma. In this study, we investigate the association between reduction of laminin-binding glycans on α-DG and the degree of tumor cell differentiation and/or infiltrative properties, as assessed by the Gleason grading system.

METHODS

Immunohistochemical analysis of 146 biopsy specimens of prostate adenocarcinoma with various Gleason scores was carried out employing IIH6 and 6C1 antibodies, which recognize laminin-binding glycans on α-DG and α-DG core proteins, respectively. Double immunofluorescence staining was performed to evaluate colocalization of α-DG and laminin, and to determine which types of epithelial cells express laminin-binding glycans on α-DG.

RESULTS

Reduction of α-DG glycosylation, rather than loss of α-DG core protein, was correlated with higher Gleason patterns. Reduction was most conspicuous at the interface between carcinoma cells and the basement membrane. In addition, in non-neoplastic prostate glands, laminin-binding glycans were expressed predominantly on the basolateral surface of basal cells.

CONCLUSIONS

Reduced expression of laminin-binding glycans on α-DG may contribute to formation of highly infiltrative behavior of prostate carcinoma cells. Substantial reduction of laminin-binding glycans in carcinoma tissue could be partly ascribed to disappearance of pre-existing basal cells.