[Application of CD138 Immunomagnetic Bead Sorting Combined with Fluorescence in Situ Hybridization in Multiple Myeloma].

OBJECTIVE: To compare the effects of direct fluorescence in situ hybridization (D-FISH) detection without sorting and CD138 immunomagnetic bead sorting technology combined with FISH (MACS-FISH) on cytogenetic analysis of patients with multiple myeloma (MM). METHODS: FISH test results of 229 patients with initial MM were retrospectively analyzed. The patients were divided into two groups, 140 patients were tested with D-FISH and 89 patients with MACS-FISH. The combination probe was designed as P53, D13S319, RB1, 1q21, and IgH. Cytogenetic detection results were compared between the two groups. RESULTS: The total detection rate of cytogenetic abnormalities in D-FISH group was 52.9%, and that in MACS-FISH group was 79.8%. There was a significant difference in the cytogenetic abnormality rate between the two groups (P=0.020). The abnormal genes with the highest detection rate in the two groups were 1q21 and IgH, respectively, while the lowest was P53. There was no significant difference in the percentage of P53 positive cells (positive rate) between the two groups, while D13S319, RB1, 1q21, and IgH showed significant difference in positive cell rate (P=0.0002, P<0.0001, P=0.0033, P=0.0032). There was no significant correlation between the proportion of plasma cells (PC) detected by bone marrow morphology and cytogenetic abnormality rate in the D-FISH group, while there was a correlation between the proportion of PC detected by flow cytometry and cytogenetic abnormality rate (r=0.364). The PC proportion detected by bone marrow morphology and flow cytometry in the MACS-FISH group had no correlation with the cytogenetic abnormality rate and positive cell rate of the 5 genes mentioned above. Additionally, the PC proportion detected by bone marrow morphology and flow cytometry showed significant difference (P<0.0001). CONCLUSION: CD138 immunomagnetic bead sorting combined with FISH technology can significantly improve the abnormality detection rate of MM cytogenetics.

Circulating CD138 enhances disease progression by augmenting autoreactive antibody production in a mouse model of systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a progressive autoimmune disease characterized by high levels of antibodies directed against nuclear antigens. Elevated serum CD138, a heparan sulfate-bearing proteoglycan, correlates with increased disease activity in patients with SLE, but the contribution of CD138 to lupus disease is not known. Corroborating patient data, we detected an increase in serum CD138 in MRL/MpJ-Faslpr/J (MRL/Lpr) mice (a model for SLE disease) parallel to disease activity. Although T-cell receptor ß (TCRß)+CD138+ T cells typically expand in MRL/Lpr mice as the disease progresses, surprisingly, TCRß+CD138- cells were the primary source of circulating CD138, as the transfer of TCRß+CD138- cells, but not TCRß+CD138+ cells, to young MRL/Lpr mice resulted in higher serum CD138 in the recipients. We found that trypsin was able to cleave CD138 from TCRß+CD138+ cells, and that trypsin was highly expressed in TCRß+CD138- cells. Moreover, trypsin inhibitors, the "defined trypsin inhibitor" and leupeptin, increased CD138 expression on TCRß+CD138- cells, suggesting a contribution of cleaved CD138 to the increase in blood CD138 levels. Furthermore, soluble CD138 was able to bind "a proliferation-inducing ligand" (APRIL) and enhance APRIL-mediated plasma cell generation and autoreactive antibody production through the phosphorylation of extracellular signal-regulated kinase in B cells. The APRIL receptor "transmembrane activator, calcium modulator, and cyclophilin ligand interactor" was involved in the enhancement of APRIL activity by CD138, as the synergistic effect of APRIL and CD138 was ablated in transmembrane activator, calcium modulator, and cyclophilin ligand interactor-deficient B cells. These findings indicate a regulatory role for soluble CD138 in B-cell differentiation and autoreactive antibody production in SLE disease.

Diagnosis of chronic endometritis: How many CD138+ cells/HPF in endometrial stroma affect pregnancy outcome of infertile women?

PROBLEM: The definition of chronic endometritis (CE) differs among studies, and currently, there is no accepted consensus. This study aimed to establish the minimum number of immunohistochemical analysis of CD138+ plasma cells to identify a clinically relevant CE. METHOD OF STUDY: We performed a retrospective study on 716 infertile patients who never did CE analysis and respective antibiotic treatment before. Samples were obtained by endometrial scratching in the mid-luteal phase before IVF-ET treatment. The number and distribution of CD138+ cells were analyzed by immunohistochemistry. Thirty high-power fields (HPF) were evaluated for each sample. Patients were classified in 2 main groups: (a) CD138low (<5 CD138+ cells in all HPFs), (b) CD138high (≥5 CD138+ cells in at least one HPF). Pregnancy outcome was compared among the groups. RESULTS: In the CD138high group, ß-hCG positive rate, clinical pregnancy rate and live birth rate were significantly decreased (P = .04, P = .01, P = .04, respectively). Also after adjusting for patient age, body mass index (BMI), and clinical characteristics, the ß-hCG positive rate (P = .05), clinical pregnancy rate (P = .01) and live birth rate (P = .02) were significantly lower in the CD138high than those in the CD138low group. Within the CD138low group, these parameters were not significantly different between patients without any plasma cells and patients with up to 4 plasma cells/HPF. CONCLUSION: We conclude that immunohistochemical analysis of CD138+ cells is a reliable method to detect CE which can be identified by the presence of ≥5 plasma cells in at least one out of 30 HPF.

VIS832, a novel CD138-targeting monoclonal antibody, potently induces killing of human multiple myeloma and further synergizes with IMiDs or bortezomib in vitro and in vivo.

Therapeutically targeting CD138, a define multiple myeloma (MM) antigen, is not yet approved for patients. We here developed and determined the preclinical efficacy of VIS832, a novel therapeutic monoclonal antibody (MoAb) with differentiated CD138 target binding to BB4 that is anti-CD138 MoAb scaffold for indatuximab ravtansine (BT062). VIS832 demonstrated enhanced CD138-binding avidity and significantly improved potency to kill MM cell lines and autologous patient MM cells regardless of resistance to current standard-of-care therapies, via robust antibody-dependent cellular cytotoxicity and phagocytosis mediated by NK and macrophage effector cells, respectively. Specifically, CD38-targeting daratumumab-resistant MM cells were highly susceptible to VIS832 which, unlike daratumumab, spares NK cells. Superior maximal cytolysis of VIS832 vs. daratumumab corresponded to higher CD138 vs. CD38 levels in MM cells. Furthermore, VIS832 acted synergistically with lenalidomide or bortezomib to deplete MM cells. Importantly, VIS832 at a sub-optimal dose inhibited disseminated MM1S tumors in vivo as monotherapy (P < 0.0001), and rapidly eradicated myeloma burden in all mice concomitantly receiving bortezomib, with 100% host survival. Taken together, these data strongly support clinical development of VIS832, alone and in combination, for the therapeutic treatment of MM in relapsed and refractory patients while pointing to its potential therapeutic use earlier in disease intervention.

Paving the Way toward Successful Multiple Myeloma Treatment: Chimeric Antigen Receptor T-Cell Therapy.

Despite the significant progress of modern anticancer therapies, multiple myeloma (MM) is still incurable for the majority of patients. Following almost three decades of development, chimeric antigen receptor (CAR) T-cell therapy now has the opportunity to revolutionize the treatment landscape and meet the unmet clinical need. However, there are still several major hurdles to overcome. Here we discuss the recent advances of CAR T-cell therapy for MM with an emphasis on future directions and possible risks. Currently, CAR T-cell therapy for MM is at the first stage of clinical studies, and most studies have focused on CAR T cells targeting B cell maturation antigen (BCMA), but other antigens such as cluster of differentiation 138 (CD138, syndecan-1) are also being evaluated. Although this therapy is associated with side effects, such as cytokine release syndrome and neurotoxicity, and relapses have been observed, the benefit-risk balance and huge potential drive the ongoing clinical progress. To fulfill the promise of recent clinical trial success and maximize the potential of CAR T, future efforts should focus on the reduction of side effects, novel targeted antigens, combinatorial uses of different types of CAR T, and development of CAR T cells targeting more than one antigen.

Current advances in chimeric antigen receptor T-cell therapy for refractory/relapsed multiple myeloma.

Multiple myeloma (MM), considered an incurable hematological malignancy, is characterized by its clonal evolution of malignant plasma cells. Although the application of autologous stem cell transplantation (ASCT) and the introduction of novel agents such as immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs) have doubled the median overall survival to eight years, relapsed and refractory diseases are still frequent events in the course of MM. To achieve a durable and deep remission, immunotherapy modalities have been developed for relapsed/refractory multiple myeloma (RRMM). Among these approaches, chimeric antigen receptor (CAR) T-cell therapy is the most promising star, based on the results of previous success in B-cell neoplasms. In this immunotherapy, autologous T cells are engineered to express an artificial receptor which targets a tumor-associated antigen and initiates the T-cell killing procedure. Tisagenlecleucel and Axicabtagene, targeting the CD19 antigen, are the two pacesetters of CAR T-cell products. They were approved by the US Food and Drug Administration (FDA) in 2017 for the treatment of acute lymphocytic leukemia (ALL) and diffuse large B-cell lymphoma (DLBCL). Their development enabled unparalleled efficacy in combating hematopoietic neoplasms. In this review article, we summarize six promising candidate antigens in MM that can be targeted by CARs and discuss some noteworthy studies of the safety profile of current CAR T-cell therapy.

IgG4-positive Cell Quantification Distinguishes Between Inflammatory and Noninflammatory Diseases of the Orbit.

IgG4-related ophthalmic disease (IgG4-ROD) is a rare inflammatory disorder often refractory to corticosteroids and prone to recurrence. IgG4-ROD may frequently lack the characteristic histopathological features seen in other organs. Thus, the criteria for diagnosis of IgG4-ROD relies on elevated IgG4 cells seen on biopsied tissue. Proposed threshold levels of IgG4 to diagnose IgG4-ROD are currently based on a limited understanding of this cell type's presence in the orbit. This study seeks to describe the population of IgG4 in inflammatory and noninflammatory orbital tissues. A tertiary care center's pathology database was searched with keywords "orbit" or "orbital" from 1995 to 2013. Specimens meeting the selection criteria were evaluated, and regions of highest inflammation were identified and immunostained with IgG4 and CD138 antibodies. Immunohistochemical quantification proceeded as previously established by the international consensus criteria. Eighteen cases without a history of orbital inflammation were included as controls and were evaluated as above. Specimens from 68 inflammatory and 18 noninflammatory orbits met the selection criteria. Pathologist interreader correlation coefficient on quantification was >0.70 (P<0.001). The mean IgG4+/high powered field (HPF) and IgG4+/CD138 was 10.3 and 0.1 in inflammatory tissues and 0.5 and 0.01 in noninflammatory tissues, respectively. The spearman rho correlation coefficient between IgG4/HPF and IgG4+/CD138+ was >0.95 (P<0.0001). The mean IgG4/HPF in our study reached previously proposed threshold values for diagnosis of IgG4-ROD, illustrating the need for further discussion regarding diagnostic criteria of IgG4-ROD.

Autoantigen-specific B cells and plasma cells are prominent in areas of fatty infiltration in salivary glands of patients with primary Sjögren's syndrome.

Salivary and lacrimal gland involvement is a characteristic feature of primary Sjögren's syndrome (pSS), where tissue destruction is mediated by mononuclear cell infiltration, resulting in lacrimal and salivary gland impairment. We have previously shown distinct prevalence of adipose tissue replacement in the minor salivary gland tissue from pSS patients. The salivary gland microenvironment was further examined through microarray analysis, identifying signalling pathways that promoted adipose tissue development, inflammation, and lymphoma. As B cells may also contribute to disease progression, we now aimed to study the B cell pattern with regard to adipocyte development in pSS. Double immunohistochemical staining of paraffin-embedded salivary gland tissue from 22 pSS patients and 11 non-SS tissue controls was employed, using the characteristic pSS autoantigens Ro52 or Ro60, alongside CD27. Additional CD138/CD20 double staining was also performed to identify the plasma- and general B- cell pattern. Our results demonstrated CD27-positive Ro52 and Ro60 specific cells observed within and in close proximity to the adipose tissue. CD138-positive plasma cells were also seen in areas of adipose tissue replacement, while the CD20+ cells were located within focal infiltrates, forming distinct B cell zones. The quantification of CD138+ and CD20+ cells revealed elevated numbers of CD138+ cells in areas of fatty infiltration, and also interstitially, in the salivary glands of pSS patients when compared to non-SS controls. A significant increase (p < .01) in CD138+ cells close to areas of fatty infiltration, and interstitially, with increasing fatty infiltration and focus score was further observed in pSS patients. A correlation between the number of CD20+ B cell zones/mm2 of salivary gland tissue and focus score values was also witnessed in the patients (r2 = 0.6047, p < .001). In conclusion, autoantigen-specific B cells and plasma cells appear prominent in areas of fatty infiltration in salivary glands of pSS patients, where an increase in CD138+ plasma cells and CD20+ B cells, in relation to both fatty and focal infiltration, suggests their active involvement in promoting inflammation. Further studies are needed to assess whether these adipocytes are also a result of tissue repair.

Extracellular NK histones promote immune cell anti-tumor activity by inducing cell clusters through binding to CD138 receptor.

BACKGROUND: Natural killer (NK) cells are important anti-tumor cells of our innate immune system. Their anti-cancer activity is mediated through interaction of a wide array of activating and inhibitory receptors with their ligands on tumor cells. After activation, NK cells also secrete a variety of pro-inflammatory molecules that contribute to the final immune response by modulating other innate and adaptive immune cells. In this regard, external proteins from NK cell secretome and the mechanisms by which they mediate these responses are poorly defined. METHODS: TRANS-stable-isotope labeling of amino acids in cell culture (TRANS-SILAC) combined with proteomic was undertaken to identify early materials transferred between cord blood-derived NK cells (CB-NK) and multiple myeloma (MM) cells. Further in vitro and in vivo studies with knock-down of histones and CD138, overexpression of histones and addition of exogenous histones were undertaken to confirm TRANS-SILAC results and to determine functional roles of this material transferred. RESULTS: We describe a novel mechanism by which histones are actively released by NK cells early after contact with MM cells. We show that extracellular histones bind to the heparan sulfate proteoglycan CD138 on the surface of MM cells to promote the creation of immune-tumor cell clusters bringing immune and MM cells into close proximity, and thus facilitating not only NK but also T lymphocyte anti-MM activity. CONCLUSION: This study demonstrates a novel immunoregulatory role of NK cells against MM cells mediated by histones, and an additional role of NK cells modulating T lymphocytes activity that will open up new avenues to design future immunotherapy clinical strategies.

VLA-4 phosphorylation during tumor and immune cell migration relies on its coupling to VEGFR2 and CXCR4 by syndecan-1.

When targeted by the tumor-promoting enzyme heparanase, cleaved and shed syndecan-1 (Sdc1) then couples VEGFR2 (also known as KDR) to VLA-4, activating VEGFR2 and the directed migration of myeloma cells. But how VEGFR2 activates VLA-4-mediated motility has remained unknown. We now report that VEGFR2 causes PKA-mediated phosphorylation of VLA-4 on S988, an event known to stimulate tumor metastasis while suppressing cytotoxic immune cells. A key partner in this mechanism is the chemokine receptor CXCR4, a well-known mediator of cell motility in response to gradients of the chemokine SDF-1 (also known as CXCL12). The entire machinery necessary to phosphorylate VLA-4, consisting of CXCR4, AC7 (also known as ADCY7) and PKA, is constitutively associated with VEGFR2 and is localized to the integrin by Sdc1. VEGFR2 carries out the novel phosphorylation of Y135 within the DRY microswitch of CXCR4, sequentially activating Gαißγ, AC7 and PKA, which phosphorylates S988 on the integrin. This mechanism is blocked by a syndecan-mimetic peptide (SSTNVEGFR2), which, by preventing VEGFR2 linkage to VLA-4, arrests tumor cell migration that depends on VLA-4 phosphorylation and stimulates the LFA-1-mediated migration of cytotoxic leukocytes.

The immunomodulatory role of tumor Syndecan-1 (CD138) on ex vivo tumor microenvironmental CD4+ T cell polarization in inflammatory and non-inflammatory breast cancer patients.

Herein, we aimed to identify the immunomodulatory role of tumor Syndecan-1 (CD138) in the polarization of CD4+ T helper (Th) subsets isolated from the tumor microenvironment of inflammatory breast cancer (IBC) and non-IBC patients. Lymphocytes and mononuclear cells isolated from the axillary tributaries of non-IBC and IBC patients during modified radical mastectomy were either stimulated with the secretome as indirect co-culture or directly co-cultured with control and Syndecan-1-silenced SUM-149 IBC cells. In addition, peripheral blood mononuclear cells (PBMCs) of normal subjects were used for the direct co-culture. Employing flow cytometry, we analyzed the expression of the intracellular IFN-γ, IL-4, IL-17, and Foxp3 markers as readout for basal and co-cultured Th1, Th2, Th17, and Treg CD4+ subsets, respectively. Our data revealed that IBC displayed a lower basal frequency of Th1 and Th2 subsets than non-IBC. Syndecan-1-silenced SUM-149 cells significantly upregulated only Treg subset polarization of normal subjects relative to controls. However, Syndecan-1 silencing significantly enhanced the polarization of Th17 and Treg subsets of non-IBC under both direct and indirect conditions and induced only Th1 subset polarization under indirect conditions compared to control. Interestingly, qPCR revealed that there was a negative correlation between Syndecan-1 and each of IL-4, IL-17, and Foxp3 mRNA expression in carcinoma tissues of IBC and that the correlation was reversed in non-IBC. Mechanistically, Syndecan-1 knockdown in SUM-149 cells promoted Th17 cell expansion via upregulation of IL-23 and the Notch ligand DLL4. Overall, this study indicates a low frequency of the circulating antitumor Th1 subset in IBC and suggests that tumor Syndecan-1 silencing enhances ex vivo polarization of CD4+ Th17 and Treg cells of non-IBC, whereby Th17 polarization is possibly mediated via upregulation of IL-23 and DLL4. These findings suggest the immunoregulatory role of tumor Syndecan-1 expression in Th cell polarization that may have therapeutic implications for breast cancer.

What is the Best Radionuclide for Immuno-PET of Multiple Myeloma? A Comparison Study Between 89Zr- and 64Cu-Labeled Anti-CD138 in a Preclinical Syngeneic Model.

Although positron emission tomography (PET) imaging with 18-Fluorodeoxyglucose (18F-FDG) is a promising technique in multiple myeloma (MM), the development of other radiopharmaceuticals seems relevant. CD138 is currently used as a standard marker for the identification of myeloma cells and could be used in phenotype tumor imaging. In this study, we used an anti-CD138 murine antibody (9E7.4) radiolabeled with copper-64 (64Cu) or zirconium-89 (89Zr) and compared them in a syngeneic mouse model to select the optimal tracers for MM PET imaging. Then, 9E7.4 was conjugated to TE2A-benzyl isothiocyanate (TE2A) and desferrioxamine (DFO) chelators for 64Cu and 89Zr labeling, respectively. 64Cu-TE2A-9E7.4 and 89Zr-DFO-9E7.4 antibodies were evaluated by PET imaging and biodistribution studies in C57BL/KaLwRij mice bearing either 5T33-MM subcutaneous tumors or bone lesions and were compared to 18F-FDG-PET imaging. In biodistribution and PET studies, 64Cu-TE2A-9E7.4 and 89Zr-DFO-9E7.4 displayed comparable good tumor uptake of subcutaneous tumors. On the bone lesions, PET imaging with 64Cu-TE2A-9E7.4 and 89Zr-DFO-9E7.4 showed higher uptake than with 18F-FDG-PET. Comparison of both 9E7.4 conjugates revealed higher nonspecific bone uptakes of 89Zr-DFO-9E7.4 than 64Cu-TE2A-9E7.4. Because of free 89Zr's tropism for bone when using 89Zr-anti-CD138, 64Cu-anti-CD138 antibody had the most optimal tumor-to-nontarget tissue ratios for translation into humans as a specific new imaging radiopharmaceutical agent in MM.

A novel pathway of LPS uptake through syndecan-1 leading to pyroptotic cell death.

Intracellular lipopolysaccharide (LPS) triggers the non-canonical inflammasome pathway, resulting in pyroptosis of innate immune cells. In addition to its well-known proinflammatory role, LPS can directly cause regression of some tumors, although the underlying mechanism has remained unknown. Here we show that secretoglobin(SCGB)3A2, a small protein predominantly secreted in airways, chaperones LPS to the cytosol through the cell surface receptor syndecan-1; this leads to pyroptotic cell death driven by caspase-11. SCGB3A2 and LPS co-treatment significantly induced pyroptosis of macrophage RAW264.7 cells and decreased cancer cell proliferation in vitro, while SCGB3A2 treatment resulted in reduced progression of xenograft tumors in mice. These data suggest a conserved function for SCGB3A2 in the innate immune system and cancer cells. These findings demonstrate a critical role for SCGB3A2 as an LPS delivery vehicle; they reveal one mechanism whereby LPS enters innate immune cells leading to pyroptosis, and they clarify the direct effect of LPS on cancer cells.

Synthesis of C-functionalized TE1PA and comparison with its analogues. An example of bioconjugation on 9E7.4 mAb for multiple myeloma 64Cu-PET imaging.

In view of the excellent copper(ii) and 64-copper(ii) complexation of a TE1PA ligand, a monopicolinate cyclam, in both aqueous medium and in vivo, we looked for a way to make it bifunctional, while maintaining its chelating properties. Overcoming the already known drawback of grafting via its carboxyl group, which is essential to the overall properties of the ligand, a TE1PA bifunctional derivative bearing an additional isothiocyanate coupling function on a carbon atom of the macrocyclic ring was synthesized. This led to an architecture that is comparable to that of other commercially available bifunctional copper(ii) chelators such as p-SCN-Bn-DOTA already used in clinical trials for 64Cu-immuno-PET imaging. The C-functionalization of TE1PA on one carbon atom in the ß-N position of the cyclam backbone was successfully achieved by adapting our patented methodology to the huge challenge, allowing the regiospecific mono-N-functionalization of the unsymmetrical ligand. The obtained ligand p-SCN-Bn-TE1PA was coupled to a 9E7.4 murine antibody (mAb), an IgG2a anti CD-138 for multiple myeloma (MM) targeting. The conjugation efficiency was assessed by looking at the 64Cu radiolabeling and the radiopharmaceutical 64Cu-9E7.4-p-SCN-Bn-TE1PA immunoreactivity, and in particular by comparing with 9E7.4-p-SCN-Bn-NOTA and 9E7.4-p-SCN-Bn-DOTA obtained from commercial and presumably highly efficient chelators NOTA and DOTA, respectively. The results are quite clear, showing that p-SCN-Bn-TE1PA has a coupling rate 5 times higher and an immunoreactivity 1.5 to 2 times greater than those of its two competitors. p-SCN-Bn-TE1PA also outperforms TE1PA conjugated via its carboxylic function on the same antibody. The first 64Cu-immuno-PET preclinical study in a syngeneic model of MM was performed, confirming the good in vivo properties of 64Cu-9E7.4-p-SCN-Bn-TE1PA for PET imaging, considering the high clearance even after 24 h and the particularly important tumor-to-liver ratio that was increasing at 48 h.

A Novel Subset of Anti-Inflammatory CD138+ Macrophages Is Deficient in Mice with Experimental Lupus.

Dead cells accumulating in the tissues may contribute to chronic inflammation. We examined the cause of impaired apoptotic cell clearance in human and murine lupus. Dead cells accumulated in bone marrow from lupus patients but not from nonautoimmune patients undergoing myeloablation, where they were efficiently removed by macrophages (MΦ). Impaired apoptotic cell uptake by MΦ also was seen in mice treated i.p. with pristane (develop lupus) but not mineral oil (MO) (do not develop lupus). The inflammatory response to both pristane and MO rapidly depleted resident (Tim4+) large peritoneal MΦ. The peritoneal exudate of pristane-treated mice contained mainly Ly6Chi inflammatory monocytes; whereas in MO-treated mice, it consisted predominantly of a novel subset of highly phagocytic MΦ resembling small peritoneal MΦ (SPM) that expressed CD138+ and the scavenger receptor Marco. Treatment with anti-Marco-neutralizing Abs and the class A scavenger receptor antagonist polyinosinic acid inhibited phagocytosis of apoptotic cells by CD138+ MΦ. CD138+ MΦ expressed IL-10R, CD206, and CCR2 but little TNF-α or CX3CR1. They also expressed high levels of activated CREB, a transcription factor implicated in generating alternatively activated MΦ. Similar cells were identified in the spleen and lung of MO-treated mice and also were induced by LPS. We conclude that highly phagocytic, CD138+ SPM-like cells with an anti-inflammatory phenotype may promote the resolution of inflammation in lupus and infectious diseases. These SPM-like cells are not restricted to the peritoneum and may help clear apoptotic cells from tissues such as the lung, helping to prevent chronic inflammation.

A subset of high Gleason grade prostate carcinomas contain a large burden of prostate cancer syndecan-1 positive stromal cells.

BACKGROUND: There is a pressing need to identify prognostic and predictive biomarkers for prostate cancer to aid treatment decisions in both early and advanced disease settings. Syndecan-1, a heparan sulfate proteoglycan, has been previously identified as a potential prognostic biomarker by multiple studies at the tissue and serum level. However, other studies have questioned its utility. METHODS: Anti-Syndecan-1 immunohistochemistry was carried out on 157 prostate tissue samples (including cancerous, adjacent normal tissue, and non-diseased prostate) from three independent cohorts of patients. A population of Syndecan-1 positive stromal cells was identified and the number and morphological parameters of these cells quantified. The identity of the Syndecan-1-positive stromal cells was assessed by multiplex immunofluorescence using a range of common cell lineage markers. Finally, the burden of Syndecan-1 positive stromal cells was tested for association with clinical parameters. RESULTS: We identified a previously unreported cell type which is marked by Syndecan-1 expression and is found in the stroma of prostate tumors and adjacent normal tissue but not in non-diseased prostate. We call these cells Prostate Cancer Syndecan-1 Positive (PCSP) cells. Immunofluorescence analysis revealed that the PCSP cell population did not co-stain with markers of common prostate epithelial, stromal, or immune cell populations. However, morphological analysis revealed that PCSP cells are often elongated and displayed prominent lamellipodia, suggesting they are an unidentified migratory cell population. Analysis of clinical parameters showed that PCSP cells were found with a frequency of 20-35% of all tumors evaluated, but were not present in non-diseased normal tissue. Interestingly, a subset of primary Gleason 5 prostate tumors had a high burden of PCSP cells. CONCLUSIONS: The current study identifies PCSP cells as a novel, potentially migratory cell type, which is marked by Syndecan-1 expression and is found in the stroma of prostate carcinomas, adjacent normal tissue, but not in non-diseased prostate. A subset of poor prognosis high Gleason grade 5 tumors had a particularly high PCSP cell burden, suggesting an association between this unidentified cell type and tumor aggressiveness.

Expression of IL-17 and syndecan-1 in nasal polyps and their correlation with nasal polyps.

Nasal polyp (NP) is a common chronic inflammatory disease of the nasal cavity and sinuses. Although some authors have suggested that NP is related to inflammatory factors such as interleukin (IL)-1ß, IL-5, IL-8, granulocyte-macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor (TNF)-α, and IL-17, the mechanisms underlying the pathogenesis and progression of NP remain obscure. This study investigated the expression and distribution of IL-17 and syndecan-1 in NP, and explored the roles of these two molecules in the pathogenesis of eosinophilic chronic rhinosinusitis with nasal polyps (Eos CRSwNP) and non-Eos CRSwNP. Real-time PCR and immunohistochemistry were used to detect the expression of IL-17 and syndecan-1 in samples [NP, unciform process (UP) from patients with CRS, and middle turbinate (MT) from healthy controls undergoing pituitary tumor surgery]. The results showed that the expression levels of IL-17 and syndecan-1 were upregulated in both NP and UP tissues, but both factors were higher in NP tissues than in UP tissues. There was no significant difference in IL-17 levels between the Eos CRSwNP and non-Eos CRSwNP samples, and syndecan-1 levels were increased in the non-Eos CRSwNP tissues as compared with those in Eos CRSwNP tissues. In all of the groups, there was a close correlation between the expression of IL-17 and syndecan-1 in nasal mucosa epithelial cells, glandular epithelial cells, and inflammatory cells, suggesting that IL-17 and syndecan-1 may play a role, and interact with each other, in the pathogenesis of non-Eos CRSwNP.

Stable and Potent Selenomab-Drug Conjugates.

Selenomabs are engineered monoclonal antibodies with one or more translationally incorporated selenocysteine residues. The unique reactivity of the selenol group of selenocysteine permits site-specific conjugation of drugs. Compared with other natural and unnatural amino acid and carbohydrate residues that have been used for the generation of site-specific antibody-drug conjugates, selenocysteine is particularly reactive, permitting fast, single-step, and efficient reactions under near physiological conditions. Using a tailored conjugation chemistry, we generated highly stable selenomab-drug conjugates and demonstrated their potency and selectivity in vitro and in vivo. These site-specific antibody-drug conjugates built on a selenocysteine interface revealed broad therapeutic utility in liquid and solid malignancy models.

Indatuximab ravtansine (BT062) combination treatment in multiple myeloma: pre-clinical studies.

Indatuximab ravtansine is a monoclonal antibody-linked cytotoxic agent that specifically targets CD138-expressing cells. Monotherapy has been shown to significantly inhibit multiple myeloma tumour growth in vivo and improve host survival. Here, we show that in most cell lines tested, indatuximab ravtansine acts additively or even synergistically with clinically approved therapies for treatment of multiple myeloma. In addition, in vivo mouse xenograft models confirmed the activity of indatuximab ravtansine in combination with lenalidamide and lenalidomide/dexamethasone. Indatuximab ravtansine may therefore be a suitable combination partner for multiple myeloma, and a clinical study is ongoing.

Death receptor 6 contributes to autoimmunity in lupus-prone mice.

Expansion of autoreactive follicular helper T (Tfh) cells is tightly restricted to prevent induction of autoantibody-dependent immunological diseases, such as systemic lupus erythematosus (SLE). Here we show expression of an orphan immune regulator, death receptor 6 (DR6/TNFRSF21), on a population of Tfh cells that are highly expanded in lupus-like disease progression in mice. Genome-wide screening reveals an interaction between syndecan-1 and DR6 resulting in immunosuppressive functions. Importantly, syndecan-1 is expressed specifically on autoreactive germinal centre (GC) B cells that are critical for maintenance of Tfh cells. Syndecan-1 expression level on GC B cells is associated with Tfh cell expansion and disease progression in lupus-prone mouse strains. In addition, Tfh cell suppression by DR6-specific monoclonal antibody delays disease progression in lupus-prone mice. These findings suggest that the DR6/syndecan-1 axis regulates aberrant GC reactions and could be a therapeutic target for autoimmune diseases such as SLE.