Moesin: A novel receptor on NK lymphocytes binds to TOMM40 on K562 leukemia cells initiating cytolysis.

Natural killer lymphocytes (NK cells) are the first line of defense (innate immunity) against viral infections and leukemia since they do not require activation to deliver a lethal hit to infected/aberrant cells. In contrast, T lymphocytes require stimulation by a foreign/neo - antigen, which may take days before they are active against the pathogen (adaptive immunity). A number of receptors on activated NK cells that kill the prototypical leukemia target cell line, K562, have been identified. To date, the receptor(s) by which freshly isolated unstimulated NK cells (naïve, nNK) kill K562 has not been fully elucidated. We provide peptide sequence and immune-blot data from ligand pull down experiments that moesin, a protein that typically links the inner leaf of the plasma membrane to the cytoskeleton, additionally, in NK cells, localizes to the cell surface where it may bind to its ligand, TOMM40 (aka Haymaker, HYMKR), on leukemia cells thereby initiating their destruction. Flow cytometry experiments with a mouse monoclonal antibody (Mab) to a moesin peptide (554 to 565) were performed. Moesin was detected on the surface of CD3-, CD16+nNK cells but was not detected on the surface of freshly isolated unstimulated CD3+, CD16- T cells or CD19+, CD16- B cells from healthy subjects. Moesin, is therefore another marker that distinguishes unstimulated CD3-, CD16+ NK cells from other non-activated lymphocytes. The anti -moesin peptide Mab was highly effective (>95% inhibition) in blocking target cell cytolysis by CD16+ lymphocytes demonstrating that moesin-HYMKR interaction appears to be necessary for most of the observed cell death of K562 caused by unstimulated NK cells.

Molecular Pathology Techniques: Advances in 2018.

Molecular pathology techniques continue to evolve. Although polymerase chain reaction (PCR) remains the cornerstone methodology for nucleic acid amplification, improvements in nucleic acid detection methodologies (i.e. PCR) have increased the detection sensitivity by using fluorescent and bead based array technologies. Single base pair lesions can be detected via sequencing and related techniques to discern point mutations in disease pathogenesis. Novel technologies, such as high- resolution melting analysis, provide fast high throughput post PCR analysis of genetic mutations or variance in nucleic acid sequences. These and other technologies such as hybrid capture, fluorohore and chemiluminescence detections assays allow for rapid diagnosis and prognosis for expeditious and personalized patient management.

Alterations in DNA Damage Response and Repair Genes as Potential Marker of Clinical Benefit From PD-1/PD-L1 Blockade in Advanced Urothelial Cancers.

Purpose Alterations in DNA damage response and repair (DDR) genes are associated with increased mutation load and improved clinical outcomes in platinum-treated metastatic urothelial carcinoma. We examined the relationship between DDR alterations and response to PD-1/PD-L1 blockade. Methods Detailed demographic, treatment response, and long-term outcome data were collected on patients with metastatic urothelial carcinoma treated with atezolizumab or nivolumab who had targeted exon sequencing performed on pre-immunotherapy tumor specimens. Presence of DDR alterations was correlated with best objective response per Response Evaluation Criteria in Solid Tumors (RECIST) and progression-free and overall survival. Results Sixty patients with urothelial cancer enrolled in prospective trials of anti-PD-1/PD-L1 antibodies met inclusion criteria. Any DDR and known or likely deleterious DDR mutations were identified in 28 (47%) and 15 (25%) patients, respectively. The presence of any DDR alteration was associated with a higher response rate (67.9% v 18.8%; P < .001). A higher response rate was observed in patients whose tumors harbored known or likely deleterious DDR alterations (80%) compared with DDR alterations of unknown significance (54%) and in those whose tumors were wild-type for DDR genes (19%; P < .001). The correlation remained significant in multivariable analysis that included presence of visceral metastases. DDR alterations also were associated with longer progression-free and overall survival. Conclusion DDR alterations are independently associated with response to PD-1/PD-L1 blockade in patients with metastatic urothelial carcinoma. These observations warrant additional study, including prospective validation and exploration of the interaction between tumor DDR alteration and other tumor/host biomarkers of immunotherapy response.

Combined KIT and CTLA-4 Blockade in Patients with Refractory GIST and Other Advanced Sarcomas: A Phase Ib Study of Dasatinib plus Ipilimumab.

Purpose: A phase Ib study of dasatinib plus ipilimumab in patients with gastrointestinal stromal tumor (GIST) and other sarcomas was performed on the basis of preclinical data demonstrating that combined KIT and CTLA-4 blockade is synergistic.Experimental Design: A standard 3 + 3 design was used to evaluate the safety, efficacy, and immune correlates of treatment. Dose escalation cohorts received ipilimumab 10 or 3 mg/kg every 3 weeks, followed by maintenance every 12 weeks with escalating doses of dasatinib (70 mg daily, 100 mg daily, or 70 mg twice daily). Response was assessed by RECIST 1.1, Choi, and immune-related RECIST criteria (irRC).Results: A total of 28 patients (17 male) were enrolled. Histologic subtypes included GISTs (n = 20) and other sarcomas (n = 8.) Dasatinib 70 mg/day with ipilimumab 10 mg/kg or dasatinib 140 mg/day with ipilimumab 3 mg/kg can be safely administered. Dose-limiting toxicities included grade 3 gastric hemorrhage and anemia. No partial or complete responses were noted by RECIST or irRC. There were 7 of 13 partial responses in the GIST patients by Choi criteria, and 3 of 13 patients each had stable and progressive disease, respectively.Conclusions: Dasatinib and ipilimumab can be safely administered to GIST and sarcoma patients. However, dasatinib was not synergistic with ipilimumab, as there was limited clinical efficacy with the combination. This limited cohort provides prospective data that indoleamine-2,3-dioxygenase (IDO) suppression may potentially correlate with antitumor efficacy in GIST. Given the small cohort, it is only hypothesis generating and additional data would be required. In the era of more modern and effective checkpoint inhibitors, next steps could be consideration of tyrosine kinase inhibitors or IDO inhibitors in combination with anti-PD-1 therapy. Clin Cancer Res; 23(12); 2972-80. ©2016 AACR.

Clinical features and response to systemic therapy in a historical cohort of advanced or unresectable mucosal melanoma.

There are very few data available regarding the pattern of first metastases in resected mucosal melanomas (MMs) as well as the response of advanced MM to cytotoxic therapy. A retrospective, single-institution cohort was assembled of all patients with advanced/unresectable MM between 1995 and 2012 who had received systemic therapy with available imaging (N=81). Responses to first-line and second-line systemic therapy were assessed using Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. The relationship between response, overall survival, and clinical covariates was investigated using Cox proportional hazards regression. Primary sites included anorectal (N=31, 38%), vulvovaginal (N=28, 35%), head and neck (N=21, 26%), and gallbladder (N=1, 1%) mucosa. Seven percent of patients had their first relapse in the brain. Cytotoxic therapy represented 82 and 51% of first-line and second-line regimens. The best response achieved in the first-line setting was similar for single-agent [10%; 95% confidence interval (CI): 1-32%] and combination alkylator therapy (8%; 95% CI: 2-21%). Median overall survival from first-line treatment was 10.3 months (95% CI: 8.7-13.9 months). Patients with elevated lactic dehydrogenase [hazard ratio (HR): 1.87, 95% CI: 1.10-3.19, P=0.020] and Eastern Cooperative Oncology Group performance status 1-2 (HR: 1.69, 95% CI: 1.05-2.72, P=0.030) had a higher risk of death, whereas patients with 12-week objective responses had a lower risk of death (HR: 0.12, 95% CI: 0.04-0.41, P<0.001). Cytotoxic systemic therapy has modest activity in advanced/unresectable MM, belying its adjuvant benefit. Patients whose tumors have an objective response to therapy have a lower probability of death. Brain imaging should be considered in routine surveillance.

Molecular pathology techniques.

Molecular pathology techniques have matured considerably over the last decade. New technologies have provided increased sensitivity for improved diagnostic capacity. Furthermore, novel methodologies have matured to interrogate nucleic acid and protein signatures effectively to aid in elucidating the pathophysiology of disease in addition to diagnosis, prognosis, and therapeutic monitoring for patient management. Here general molecular techniques used in the molecular pathology laboratory as they are used for clinical applications are described.

Ipilimumab for patients with advanced mucosal melanoma.

The outcome of patients with mucosal melanoma treated with ipilimumab is not defined. To assess the efficacy and safety of ipilimumab in this melanoma subset, we performed a multicenter, retrospective analysis of 33 patients with unresectable or metastatic mucosal melanoma treated with ipilimumab. The clinical characteristics, treatments, toxicities, radiographic assessment of disease burden by central radiology review at each site, and mutational profiles of the patients' tumors were recorded. Available peripheral blood samples were used to assess humoral immunity against a panel of cancer-testis antigens and other antigens. By the immune-related response criteria of the 30 patients who underwent radiographic assessment after ipilimumab at approximately week 12, there were 1 immune-related complete response, 1 immune-related partial response, 6 immune-related stable disease, and 22 immune-related progressive disease. By the modified World Health Organization criteria, there were 1 immune-related complete response, 1 immune-related partial response, 5 immune-related stable disease, and 23 immune-related progressive disease. Immune-related adverse events (as graded by Common Terminology Criteria for Adverse Events version 4.0) consisted of six patients with rash (four grade 1, two grade 2), three patients with diarrhea (one grade 1, two grade 3), one patient with grade 1 thyroiditis, one patient with grade 3 hepatitis, and 1 patient with grade 2 hypophysitis. The median overall survival from the time of the first dose of ipilimumab was 6.4 months (range: 1.8-26.7 months). Several patients demonstrated serologic responses to cancer-testis antigens and other antigens. Durable responses to ipilimumab were observed, but the overall response rate was low. Additional investigation is necessary to clarify the role of ipilimumab in patients with mucosal melanoma.

Langerhans cells from human cutaneous squamous cell carcinoma induce strong type 1 immunity.

Langerhans cells (LCs) are dendritic cells (DCs) localized to the epidermis. They should be the first antigen-presenting cells to encounter squamous cell carcinoma (SCC). The aim of this study was to investigate the ability of LCs isolated from human SCC to induce T-cell proliferation and polarization. We investigated the ability of LCs from SCC and peritumoral skin to induce T-cell proliferation and polarization. We also studied the effect of SCC supernatant on the ability of LCs from normal skin, in vitro-generated LCs, and DCs to activate and polarize T cells. LCs from SCC were stronger inducers of allogeneic CD4(+) and CD8(+) T-cell proliferation and IFN-γ production than LCs from peritumoral skin. We found that tumor supernatants (TSNs) were rich in immunosuppressive cytokines; despite this, allogeneic CD4(+) and CD8(+) T-cell proliferation and IFN-γ induction by LCs were augmented by TSN. Moreover, TSN facilitated IFN-γ induction by in vitro-generated LCs, but suppressed the ability of in vitro-generated DCs to expand allogeneic CD4(+) and CD8(+) T cells. We have demonstrated that LCs from SCC can induce type 1 immunity. TSN induces IFN-γ induction by in vitro-generated LCs. This contrasts greatly with prior studies showing that DCs from SCC cannot stimulate T cells. These data indicate that LCs may be superior to DCs for SCC immunotherapy and may provide a new rationale for harnessing LCs for the treatment of cancer patients.

Tumor-associated macrophages in the cutaneous SCC microenvironment are heterogeneously activated.

Tumor-associated macrophages (TAMs) may have an important role in tumor immunity. We studied the activation state of TAMs in cutaneous SCC, the second most common human cancer. CD163 was identified as a more abundant, sensitive, and accurate marker of TAMs when compared with CD68. CD163(+) TAMs produced protumoral factors, matrix metalloproteinases 9 and 11 (MMP9 and MMP11), at the gene and protein levels. Gene set enrichment analysis (GSEA) was used to evaluate M1 and M2 macrophage gene sets in the SCC genes and to identify candidate genes in order to phenotypically characterize TAMs. There was coexpression of CD163 and alternatively activated "M2" markers, CD209 and CCL18 (chemokine (C-C motif) ligand 18). There was enrichment for classically activated "M1" genes in SCC, which was confirmed in situ by colocalization of CD163 and phosphorylated STAT1 (signal transducer and activator of transcription 1), IL-23p19, IL-12/IL-23p40, and CD127. Also, a subset of TAMs in SCC was bi-activated as CD163(+) cells expressed markers for both M1 and M2, shown by triple-label immunofluorescence. These data support heterogeneous activation states of TAMs in SCC, and suggest that a dynamic model of macrophage activation would be more useful to characterize TAMs.

The human cutaneous squamous cell carcinoma microenvironment is characterized by increased lymphatic density and enhanced expression of macrophage-derived VEGF-C.

Metastases from primary cutaneous squamous cell carcinoma (SCC) account for the majority of the ∼10,000 non-melanoma skin cancer deaths in the United States annually. We studied lymphangiogenesis in human SCC because of the potential link to metastasis. SCC samples were stained for lymphatic endothelial vessel marker LYVE-1 and positive cells were counted and compared with cells in normal skin. Gene set enrichment analysis and reverse transcription (RT)-PCR were performed on SCC, on adjacent non-tumor-bearing skin, and on normal skin to determine the differential expression of lymphangiogenesis-associated genes. Laser capture microdissection (LCM) was performed to isolate tumor cells and tumor-associated inflammatory cells for further gene expression analysis. Immunofluorescence was performed to determine the source of vascular endothelial growth factor-C (VEGF-C) in the tumor microenvironment. We found increased lymphatic density and reorganized lymphatic endothelial vessels in the dermis immediately adjacent to SCC nests. RT-PCR confirmed the presence of VEGF-C in skin immediately adjacent to SCC. LCM confirmed the increased expression of VEGF-C, the SCC inflammatory infiltrate. The presence of CD163(+)/CD68(+)/VEGFC(+) cells and absence of VEGF-C expression by CD3(+) or CD11C(+) cells suggested that VEGF-C is derived from tumor-associated macrophages. Clarification of mechanisms governing SCC-mediated lymphangiogenesis may identify potential targets for therapeutic intervention against aggressive or inoperable disease.

Peripheral blood mononuclear cell gene array profiles in patients with overactive bladder.

OBJECTIVES: To investigate the utility of using peripheral blood mononuclear cells (PBMC) as a marker for patients with overactive bladder (OAB). Patients with OAB may suffer from varying degrees of symptoms such as frequency, urgency, nocturia, and incontinence; however, there is no definitive test for OAB at this time. Questionnaires may provide useful tools for screening patients for OAB but often clinicians may need to rely on more invasive procedures to confirm the diagnosis. We have previously demonstrated that PBMC can provide a reporter function in solid organ retroperitoneal disease. METHODS: Twenty-one patients were assessed for OAB. PBMC was obtained from whole blood of the patients, and RNA was subjected to microarray gene chip analysis. RESULTS: Microarray analysis revealed that 16 genes were differentially regulated (8 upregulated and 8 downregulated) in all patients with OAB in comparison with healthy controls. A sex-based analysis demonstrated 74 genes that were differentially regulated in males (25 upregulated and 49 downregulated), and 30 in females (13 upregulated and 17 downregulated). Of these platelet-derived growth factors, microfibrillar-associated protein and tropomyosin were downregulated in all sets that were analyzed. CONCLUSIONS: Microarray analysis revealed many genes that were differentially regulated in PBMC from OAB patients, including regulatory elements and genes encoding structural proteins, which may be important in regulating structural integrity of the bladder and supporting tissues. These data suggest that PBMC can provide a reporter function for patients with OAB and may serve as a diagnostic marker and elucidate genes involved in this condition.

Myeloid dendritic cells from human cutaneous squamous cell carcinoma are poor stimulators of T-cell proliferation.

To determine the phenotype and function of myeloid dendritic cells (DCs) from human cutaneous squamous-cell carcinoma (SCC), we studied their surface marker expression and allo-stimulatory potential ex vivo. There were abundant CD11c(+) myeloid DCs, as well as TNF and inducible nitric oxide synthase (iNOS)-producing DCs, in and around SCC tumor nests. Although myeloid DCs from SCC, adjacent non-tumor-bearing skin, and normal skin, were phenotypically similar by flow cytometry, and there was a pronounced genomic signature of mature DCs in SCC, they showed different T-cell stimulatory potential in an allogeneic mixed leukocyte reaction. Myeloid DCs from SCC were less potent stimulators of allogeneic T-cell proliferation than DCs from non-tumor-bearing skin. Culture with a DC-maturing cytokine cocktail (IL-1beta, IL-6, TNF-alpha, and PGE(2)) enhanced stimulatory potential in DCs from non-tumor-bearing skin, whereas SCC-associated DCs remained poor stimulators of T-cell proliferation. The microenvironment associated with SCC showed expression of TGF-beta, IL-10, and VEGF-A, factors capable of suppressing the DC function. These findings indicate that CD11c(+)/HLA-DR(hi) DCs from SCC are mature, but are not potent stimulators of T-cell proliferation compared with phenotypically similar DCs isolated from non-tumor-bearing skin. Identification of mechanisms responsible for suppression of tumor-associated DCs may provide insight into the evasion of immunosurveillance by SCC.

Amelioration of epidermal hyperplasia by TNF inhibition is associated with reduced Th17 responses.

Biological agents have dramatically improved treatment options for patients with severe psoriasis. Etanercept (tumor necrosis factor [TNF] receptor-immunoglobulin fusion protein) is an effective treatment for many psoriasis patients, and blockade of TNF is considered to be its primary action. However, in this clinical trial, we show that etanercept has early inhibitory effects on a newly appreciated type of T cells: T helper type 17 (Th17) cells. Etanercept reduced the inflammatory dendritic cell products that drive Th17 cell proliferation (interleukin [IL] 23), as well as Th17 cell products and downstream effector molecules (IL-17, IL-22, CC chemokine ligand 20, and beta-defensin 4). In contrast, Th1 cellular products and effector molecules (interferon gamma, lymphotoxin alpha, and myxovirus resistance 1) were reduced late in disease resolution. This study suggests a role for Th17 in addition to Th1 cells in the pathogenesis of psoriasis. Th17 cells may be particularly important in driving epidermal activation in psoriatic plaques, whereas Th1 cells must also be eliminated for final disease resolution.