Cellular immune response in human melanoma : Insights for patient tailored therapy

Meijer, C.J.L.M. [Promotor]Oudejans, J.J. [Copromotor]Hooijberg, E. [Copromotor

Absence of Granzyme B positive tumour-infiltrating lymphocytes in primary melanoma excisional biopsies is strongly associated with the presence of sentinel lymph node metastasis.

Contains fulltext : 79607.pdf (publisher's version ) (Open Access)BACKGROUND: Sentinel Lymph Node (SLN) status is strongly related to clinical outcome in melanoma patients. In this study we investigated the possible association between the presence of activated and/or suppressive Tumour Infiltrating Lymphocytes (TILs) and SLN status in clinically stage I/II melanoma patients. METHODS: Diagnostic primary melanoma samples from 20 patients with a sentinel lymph node metastasis were compared to melanoma samples from 20 patients with a negative sentinel lymph node, who were matched for gender, age and Breslow thickness. Presence of activated Granzyme B positive (GrB+) TILs, presence of suppressive (FoxP3+) TILs and MHC class I antigen expression on tumour cells were analysed by immunohistochemistry. RESULTS: FoxP3 and MHC-I expression had no direct bearing on the presence of melanoma metastases in the SLN. Whereas the presence of activated GrB+ TILs in the primary melanoma had no predictive value for SLN status either, their absence was strongly associated with the presence of metastasis in the SLN (p=0.001). While both GrB+ and FoxP3+ TILs could be detected in SLN metastases, a majority did not display MHC-I expression. CONCLUSION: These data support a role for cytotoxic T cells in the prevention of early metastasis of melanoma to the draining lymph nodes

Intracellular serpin SERPINB6 (PI6) is abundantly expressed by human mast cells and forms complexes with beta-tryptase monomers.

Contains fulltext : 57859.pdf (publisher's version ) (Closed access)SERPINB6 (PI6) is a member of the intracellular serine protease inhibitors (serpins). Previous studies showed that SERPINB6 is localized mainly in the cytoplasm of endothelial cells, some epithelial cells, monocytes, and neutrophils. In these cells SERPINB6 is thought to prevent cellular damage by scavenging leaking lysosomal proteases. We show here, using novel, well-defined monoclonal antibodies, that SERPINB6 is abundantly expressed by mast cells in all organs and by the human mast cell line HMC-1. Gel filtration experiments revealed that the latter cells contain a high-molecular-weight form of SERPINB6, which consists of sodium dodecyl sulfate (SDS)-stable complexes of this inhibitor with monomeric beta-tryptase. Expression of SERPINB6 by mast cells was compared with those of tryptase and CD117 (c-kit) in biopsies from patients with different forms of mast cell disease. In all cases the lesional mast cells expressed SERPINB6, and, in diffuse cutaneous mastocytosis and mastocytoma, SERPINB6 was expressed by a substantially higher number of mast cells when compared with tryptase. In conclusion, SERPINB6 is abundantly expressed by normal mast cells and by mast cells in mastocytoma lesions. We suggest that in mast cells, SERPINB6 serves to regulate the activity of endogenous beta-tryptase in the cytoplasm

QTL for body weight, morphometric traits and stress response in European sea bass Dicentrarchus labrax.

Natural mating and mass spawning in the European sea bass (Dicentrarchus labrax L., Moronidae, Teleostei) complicate genetic studies and the implementation of selective breeding schemes. We utilized a two-step experimental design for detecting QTL in mass-spawning species: 2122 offspring from natural mating between 57 parents (22 males, 34 females and one missing) phenotyped for body weight, eight morphometric traits and cortisol levels, had been previously assigned to parents based on genotypes of 31 DNA microsatellite markers. Five large full-sib families (five sires and two dams) were selected from the offspring (570 animals), which were genotyped with 67 additional markers. A new genetic map was compiled, specific to our population, but based on the previously published map. QTL mapping was performed with two methods: half-sib regression analysis (paternal and maternal) and variance component analysis accounting for all family relationships. Two significant QTL were found for body weight on linkage group 4 and 6, six significant QTL for morphometric traits on linkage groups 1B, 4, 6, 7, 15 and 23 and three suggestive QTL for stress response on linkage groups 3, 14 and 23. The QTL explained between 8% and 38% of phenotypic variance. The results are the first step towards identifying genes involved in economically important traits like body weight and stress response in European sea bas

Expression of the apoptosis inhibitor protease inhibitor 9 predicts clinical outcome in vaccinated patients with stage III and IV melanoma.

PURPOSE: There have been reports of successful treatment of metastatic melanoma patients with active specific immunotherapy (ASI) using irradiated autologous tumor cell vaccination. It is still unknown why some patients respond and others do not. Tumor cells can evade the immune system, for example through interference with antigen presentation by down-regulation of MHC molecules or expressing proteins interfering with cytotoxic lymphocyte-induced apoptosis like the granzyme B antagonist protease inhibitor 9 (PI-9). EXPERIMENTAL DESIGN: PI-9 expression was detected in melanoma cell lines. To investigated if PI-9 is important in the response to ASI, paraffin-embedded tissues from stage III or IV melanoma patients were stained. RESULTS: PI-9 is expressed in melanoma cells and expression in metastasized melanoma cells is, in this group of patients, an adverse prognostic marker with regard to overall and disease-free survival. Moreover, loss of MHC-1 expression frequently occurs during tumor progression but is not associated with poor clinical outcome. Interestingly, melanoma patients with a favorable clinical outcome after ASI therapy usually have high percentages of activated (granzyme B-positive) tumor-infiltrating lymphocytes at time of first diagnosis and low percentages of activated lymphocytes at time of recurrent tumor. CONCLUSIONS: Expression of PI-9 in metastatic melanoma cells is associated with unfavorable clinical outcome whereas MHC-1 down-regulation is not. Although it cannot be proven that PI-9 expression is directly responsible for failure of immunotherapy, these data suggest that expression of PI-9 could be an important immune escape mechanism and that modulation of this inhibitor may enhance the efficacy of immunotherapy

Expression of c-FLIP is primarily detected in diffuse large B-cell lymphoma and Hodgkin's lymphoma and correlates with lack of caspase 8 activation.

Contains fulltext : 51775.pdf (publisher's version ) (Closed access)AIMS: Inhibition of apoptosis is important in the pathogenesis of lymphomas. c-FLIP, a regulator of caspase 8-mediated apoptosis, plays an important role in protecting normal B and T cells from apoptosis and possibly also in lymphomas. Because of contradictory reports about immunohistochemical detection of c-FLIP expression, the aim was to test the specificity of four antibodies in c-FLIP-transfected cells and subsequently to investigate expression of c-FLIP in different types of lymphoma. METHODS AND RESULTS: Two of four antibodies were specific. In primary lymphomas c-FLIP expression was restricted to Hodgkin's lymphomas (> 90%) and diffuse large B-cell lymphomas (44%). Burkitt lymphomas and indolent B-cell lymphomas were negative in all cases. No expression was detected in primary T-cell lymphomas, although expression was observed in one relapsed ALK+ anaplastic large cell lymphoma. Expression of c-FLIP was inversely correlated with caspase 8 activation. CONCLUSIONS: c-FLIP is important in escape of B cells from apoptosis during normal follicle centre cell reaction and may thus be an important early event in the development of B-cell-derived lymphomas. Moreover, non-specific staining of frequently used antibodies might explain discrepancies in different reports of c-FLIP expression

Immunohistochemical profiling of caspase signaling pathways predicts clinical response to chemotherapy in primary nodal diffuse large B-cell lymphomas.

Contains fulltext : 47593.pdf (publisher's version ) (Closed access)We used biopsy specimens of primary nodal diffuse large B-cell lymphoma (DLBCL) to investigate whether the inhibition of caspase 8 and/or 9 apoptosis signaling pathways predicts clinical outcome. Expression levels of cellular FLICE inhibitory protein (c-Flip) and numbers of active caspase 3-positive lymphoma cells were used to determine the status of the caspase 8-mediated pathway. Expression levels of Bcl-2 and X-linked inhibitor of apoptosis (XIAP) were used to determine the status of the caspase 9-mediated pathway. Expression of c-Flip, XIAP, Bcl-2, and caspase 3 activity all provided prognostic information. According to these immunohistochemical parameters, inhibition of either or both caspase signaling pathways was detected in all patients. Three groups of patients were identified, one with a caspase 8 inhibition profile, one with caspase 8 and 9 inhibition profiles, and one with a caspase 9 inhibition profile. Caspase 9 inhibition was strongly associated with poor response to chemotherapy and usually with fatal outcome, whereas caspase 8 inhibition was associated with excellent clinical outcome. Thus, our data strongly suggest that inhibition of the caspase 9-mediated pathway, but not the caspase 8-mediated pathway, is a major cause for therapy resistance in patients with nodal DLBCL

Tetraspanin CD37 protects against the development of B cell lymphoma

Contains fulltext : 165795.pdf (publisher's version ) (Closed access)Worldwide, B cell non-Hodgkin lymphoma is the most common hematological malignancy and represents a substantial clinical problem. The molecular events that lead to B cell lymphoma are only partially defined. Here, we have provided evidence that deficiency of tetraspanin superfamily member CD37, which is important for B cell function, induces the development of B cell lymphoma. Mice lacking CD37 developed germinal center-derived B cell lymphoma in lymph nodes and spleens with a higher incidence than Bcl2 transgenic mice. We discovered that CD37 interacts with suppressor of cytokine signaling 3 (SOCS3); therefore, absence of CD37 drives tumor development through constitutive activation of the IL-6 signaling pathway. Moreover, animals deficient for both Cd37 and Il6 were fully protected against lymphoma development, confirming the involvement of the IL-6 pathway in driving tumorigenesis. Loss of CD37 on neoplastic cells in patients with diffuse large B cell lymphoma (DLBCL) directly correlated with activation of the IL-6 signaling pathway and with worse progression-free and overall survival. Together, this study identifies CD37 as a tumor suppressor that directly protects against B cell lymphomagenesis and provides a strong rationale for blocking the IL-6 pathway in patients with CD37- B cell malignancies as a possible therapeutic intervention

Predictive Performance of Cardiovascular Disease Risk Prediction Algorithms in People Living With HIV

Immunogenetics and cellular immunology of bacterial infectious disease

High treatment uptake in human immunodeficiency virus/ hepatitis C virus-coinfected patients after unrestricted access to direct-acting antivirals in the Netherlands

Background The Netherlands has provided unrestricted access to direct-acting antivirals (DAAs) since November 2015. We analyzed the nationwide hepatitis C virus (HCV) treatment uptake among patients coinfected with human immunodeficiency virus (HIV) and HCV. Methods Data were obtained from the ATHENA HIV observational cohort in which >98% of HIV-infected patients ever registered since 1998 are included. Patients were included if they ever had 1 positive HCV RNA result, did not have spontaneous clearance, and were known to still be in care. Treatment uptake and outcome were assessed. When patients were treated more than once, data were included from only the most recent treatment episode. Data were updated until February 2017. In addition, each treatment center was queried in April 2017 for a data update on DAA treatment and achieved sustained virological response. Results Of 23574 HIV-infected patients ever linked to care, 1471 HCV-coinfected patients (69% men who have sex with men, 15% persons who [formerly] injected drugs, and 15% with another HIV transmission route) fulfilled the inclusion criteria. Of these, 87% (1284 of 1471) had ever initiated HCV treatment between 2000 and 2017, 76% (1124 of 1471) had their HCV infection cured; DAA treatment results were pending in 6% (92 of 1471). Among men who have sex with men, 83% (844 of 1022) had their HCV infection cured, and DAA treatment results were pending in 6% (66 of 1022). Overall, 187 patients had never initiated treatment, DAAs had failed in 14, and a pegylated interferon-alfa–based regimen had failed in 54. Conclusions Fifteen months after unrestricted DAA availability the majority of HIV/HCV-coinfected patients in the Netherlands have their HCV infection cured (76%) or are awaiting DAA treatment results (6%). This rapid treatment scale-up may contribute to future HCV elimination among these patients