Somatostatin receptors and their ligands in the human immune system

Maintenance of homeostasis is essential for survival of the mammalian organism. For a long time it was believed that the different systems in the human body act independently from each other to achieve this goal. However, during the last decades it has become more evident that the different systems in the human body integrate and regulate different functions in close interac

Reviewing primary Sjögren’s syndrome: Beyond the dryness - From pathophysiology to diagnosis and treatment

Primary Sjögren’s syndrome (pSS) is a systemic autoimmune disease, characterized by lymphocytic infiltration of the secretory glands. This process leads to sicca syndrome, which is the combination of dryness of the eyes, oral cavity, pharynx, larynx and/or vagina. Extraglandular manifestations may also be prevalent in patients with pSS, including cutaneous, musculoskeletal, pulmonary, renal, hematological and neurological involvement. The pathogenesis of pSS is currently not well understood, but increased activation of B cells followed by immune complex formation and autoantibody production are thought to play important roles. pSS is diagnosed using the American-European consensus group (AECG) classification criteria which include subjective symptoms and objective tests such as histopathology and serology. The treatment of pSS warrants an organ based approach,

Differential expression of somatostatin receptor subtypes in human peripheral blood mononuclear cell subsets

BACKGROUND: Somatostatin (SS)-binding sites have been demonstrated in human lymphoid tissues and peripheral blood cells. However, not much is known with respect to the SS receptor subtype (sst) expression pattern and the expression of SS itself in the immune system. OBJECTIVE: The aim of this study was to evaluate the mRNA expression of the five known sst (sst(1-5)) in peripheral blood mononuclear cell (sub)populations. Moreover, the expression of the mRNAs encoding SS and the SS-like peptide cortistatin (CST) in immune cell subsets was studied. METHODS: RT-PCR and quantitative PCR were performed to evaluate sst, SS and CST mRNA expression in cells in the basal or activated state. Fluorescence-activated cell sorter (FACS) analysis using fluorescent SS was performed to visualize sst protein on cell membranes. RESULTS: B- and T-lymphocytes selectively expressed sst(3) mRNA. sst(3) expression in B-lymphocytes was significantly lower compared with T-lymphocytes. Unstimulated, freshly isolated monocytes did not express any sst mRNA. Upon activation, monocytes selectively expressed sst(2) mRNA, whereas T-lymphocyte activation upregulated sst(3) expression. sst(2) mRNA expression on monocytes was confirmed by FACS analysis. B- and T-lymphocytes did not express SS mRNA, while both cell types expressed CST mRNA. CST mRNA expression was downregulated following T-lymphocyte activation. CONCLUSION: We demonstrate for the first time unequivocally that human peripheral blood B- and T-lymphocytes selectively express sst(3), whereas monocytes do not express sst. However, upon activation, monocytes are induced to express sst(2A). No expression of SS mRNA was detected in any cell type, whereas all cell types expressed CST mRNA. The differential expression of sst and CST mRNA in lymphocytes and monocytes s

The 11q Terminal Deletion Disorder Jacobsen Syndrome is a Syndromic Primary Immunodeficiency

Background: Jacobsen syndrome (JS) is a rare contiguous gene syndrome caused by partial deletion of the long arm of chromosome 11. Clinical features include physical and mental growth retardation, facial dysmorphism, thrombocytopenia, impaired platelet function and pancytopenia. In case reports, recurrent infections and impaired immune cell function compatible with immunodeficiency were described. However, Jacobsen syndrome has not been recognized as an established syndromic primary immunodeficiency. Goal: To evaluate the presence of immunodeficiency in a series of 6 patients with JS. Methods: Medical history of 6 patients with JS was evaluated for recurrent infections. IgG, IgA, IgM and specific antibodies against S. pneumoniae were measured. Response to immunization with a polysaccharide vaccine (Pneumovax) was measured and B and T lymphocyte subset analyses were performed using flowcytometry. Results: Five out of 6 patients suffered from recurrent infections. These patients had low IgG levels and impaired response to S. pneumoniae polysaccharide vaccination. Moreover, we also found a significant decrease in the absolute number of memory B cells, suggesting a defective germinal center function. In a number of patients, low numbers of T lymphocytes and NK cells were found. Conclusions: Most patients with JS suffer from combined immunodeficiency in the presence of recurrent infections. Therefore, we consider JS a syndromic primary immunodeficiency. Early detection of immunodeficiency may reduce the frequency and severity of infections. All JS patients should therefore undergo immunological evaluation. Future studies in a larger cohort of patients will more precisely define the pathophysiology of the immunodeficiency in JS

How to select the most suitable media for your cells

Many different media are available to culture CHO cells. Most are either growth supporting or productivity supporting. Ideally, the basal medium is a growth supporting medium, while the feed medium is supporting both growth and productivity. In this study two clones producing the same mAb are compared on their response to a range of basal media. Clone I is fast-growing and low-producing, while Clone II is slower-growing, but high-producing. A panel of eleven different basal media from different vendors was evaluated for growth, titer and metabolism. An overview is given on the response of the cells to the different media. From these data media supporting cell growth and media supporting mAb productivity can be identified. To conclude, an example of the added value of combining two media is shown. By combining media that support growth or support production an optimal (feed)media system can be designed. Vendors have different philosophies when developing a medium, namely rich or lean basal media in combination with rich or lean feeds. Feed media can contain similar ingredients as their basal media or only a certain group of nutrients. Different types of CHO cells have different nutrient requirements and different clones from the same host may have different nutrients requirements. This makes choosing a medium a complex process. Which type of basal media to choose and is the connected feed medium the best choice to use as a feed? In this study we give our approach to the question: How to select the most suitable media for your cells

Exhaustion of the CD8+ T cell compartment in patients with mutations in phosphoinositide 3-kinase delta

Pathogenic gain-of-function mutations in the gene encoding phosphoinositide 3-kinase delta (PI3Kδ) cause activated PI3Kδ syndrome (APDS), a disease characterized by humoral immunodeficiency, lymphadenopathy, and an inability to control persistent viral infections including Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infections. Understanding the mechanisms leading to impaired immune response is important to optimally treat APDS patients. Immunosenescence of CD8+ T cells was suggested to contribute to APDS pathogenesis. However, the constitutive activation of T cells in APDS may also result in T cell exhaustion. Therefore, we studied exhaustion of the CD8+ T cell compartment in APDS patients and compared them with healthy controls and HIV patients, as a control for exhaustion. The subset distribution of the T cell compartment of APDS patients was comparable with HIV patien

Progressive APOBEC3B mRNA expression in distant breast cancer metastases

__Background:__ APOBEC3B was recently identified as a gain-of-function enzymatic source of mutagenesis, which may offer novel therapeutic options with molecules that specifically target this enzyme. In primary breast cancer, APOBEC3B mRNA is deregulated in a substantial proportion of cases and its expression is associated with poor prognosis. However, its expression in breast cancer metastases, which are the main causes of breast cancer-related death, remained to be elucidated. __Patients and methods:__ RNA was isolated from 55 primary breast cancers and paired metastases, including regional lymph node (N = 20) and distant metastases (N = 35). APOBEC3B mRNA levels were measured by RT-qPCR. Expression levels of the primary tumors and corresponding metastases were compared, including subgroup analysis by estrogen receptor (ER/ESR1) status. __Results:__ Overall, APOBEC3B mRNA levels of distant metastases were significantly higher as compared to the corresponding primary breast tumor (P = 0.0015), an effect that was not seen for loco-regional lymph node metastases (P = 0.23). Subgroup analysis by ER-status showed that increased APOBEC3B levels in distant metastases were restricted to metastases arising from ER-positive primary breast cancers (P = 0.002). However, regarding ERnegative primary tumors, only loco-regional lymph node metastases showed increased APOBEC3B expression when compared to the corresponding primary tumor (P = 0.028). __Conclusion:__ APOBEC3B mRNA levels are significantly higher in breast cancer metastases as compared to the corresponding ER-positive primary tumors. This suggests a potential role for APOBEC3B in luminal breast cancer progression, and conse

A novel heterozygous mutation in the STAT1 SH2 domain causes chronic mucocutaneous candidiasis, atypically diverse infections, autoimmunity, and impaired cytokine regulation

Chronic mucocutaneous candidiasis (CMC) is a primary immunodeficiency characterized by persistent or recurrent skin and mucosal surface infections with Candida species. Different gene mutations leading to CMC have been identified. These include various heterozygous gain-of-function (GOF) mutations in signal transducer and activator of transcription 1 (STAT1) that are not only associated with infections but also with autoimmune manifestations. Recently, two STAT1 GOF mutations involving the Src homology 2 (SH2) domain have been reported, while so far, over 50 mutations have been described mainly in the coiled coil and the DNA-binding domains. Here, we present two members of a Dutch family with a novel STAT1 mutation located in the SH2 domain. T lymphocytes of these patients revealed STAT1 hyperphosphorylation and higher expression of STAT1 target genes. The clinical picture of CMC in our patients could be explained by diminished production of interleukin (IL)-17 and IL-22, cytokines important in the protection against fungal infections

Bone Mineral Density in Sjögren Syndrome Patients with and Without Distal Renal Tubular Acidosis

Primary Sjögren’s syndrome (pSS) can be complicated by distal renal tubular acidosis (dRTA), which may contribute to low bone mineral density (BMD). Our objective was to evaluate BMD in pSS patients with and without dRTA as compared with healthy controls. BMD of lumbar spine (LS) and femoral neck (FN) was measured in 54 pSS patients and 162 healthy age- and sex-matched controls by dual-energy X-ray absorptiometry (DXA). dRTA was defined as inability to reach urinary pH <5.3 after an ammonium chloride (NH4Cl) test. LS- and FN-BMD were significantly higher in pSS patients compared with controls (1.18 ± 0.21 g/cm2 for patients vs. 1.10 ± 0.18 g/cm2 for controls, P = 0.00