Chemokine receptor CCR9 contributes to the localization of plasma cells to the small intestine

Humoral immunity in the gut-associated lymphoid tissue is characterized by the production of immunoglobulin A (IgA) by antibody-secreting plasma cells (PCs) in the lamina propria. The chemokine CCL25 is expressed by intestinal epithelial cells and is capable of inducing chemotaxis of IgA+ PCs in vitro. Using a newly generated monoclonal antibody against murine CCR9, we show that IgA+ PCs express high levels of CCR9 in the mesenteric lymph node (MLN) and Peyer's patches (PPs), but down-regulate CCR9 once they are located in the small intestine. In CCR9-deficient mice, IgA+ PCs are substantially reduced in number in the lamina propria of the small intestine. In adoptive transfer experiments, CCR9-deficient IgA+ PCs show reduced migration into the small intestine compared with wild-type controls. Furthermore, CCR9 mutants fail to mount a regular IgA response to an orally administered antigen, although the architecture and cell type composition of PPs and MLN are unaffected and are functional for the generation of IgA PCs. These findings provide profound in vivo evidence that CCL25/CCR9 guides PCs into the small intestine.     

Weight bearing evaluation in inflammatory, neuropathic and cancer chronic pain in freely moving rats

Preclinical pain assessment remains a key step for the development of new and potent painkillers. Significant progress in pain evaluation has been achieved with the development of non-reflexive tools. Seeking efficient and clinically relevant devices for pain-related quality of life assessment, we evaluated a new Dynamic Weight Bearing (DWB) device based on pressure captors in three different preclinical chronic pain models. Inflammatory (CFA), neuropathic (CCI) and bone cancer pain (femoral tumor) models were evaluated in Sprague Dawley rats for mechanical allodynia using dynamic von Frey for pain-related behaviors and DWB for discomfort. We observed similar impairment patterns in all of the models for both von Frey (allodynia) and DWB (weight balance) during the complete observation period, starting at day 3 in CCI- and CFA-affected limbs and at day 14 in bone cancer-afflicted rats, indicating that the DWB could be a useful tool for supporting pain assessment. Interestingly, we demonstrated that the main compensation, when animals experienced pain, was seen in the forepaws, ranging from 46% to 69% of increased load compared to normal. Other pain-related coping behaviors were also measured, such as the time spent on each paw and the contact surface. Our results revealed that CFA, CCI and cancerous rats decreased the use of their ipsilateral hind paws by 30% and showed a 50% reduction in paw surface pressed against the floor. In conclusion, this new device improves methods for preclinical evaluation of discomfort and quality of life proxies and could be helpful in screening putative analgesics.     

Vascular and cellular stress in inflammatory bowel disease: revisiting the role of homocysteine

Moderate hyperhomocysteinemia is a complex trait commonly associated with inflammatory bowel disease (IBD). Nutritional deficiencies and genetic determinants have been identified as risk factors for moderate hyperhomocysteinemia, such as folate and vitamin B(12) deprivation and polymorphisms in the 5,10 methylenetetrahydrofolate reductase (MTHFR) encoding gene, respectively. Homocysteine has a crucial role in cellular stress, epigenetic events, inflammatory processes, and host-microbial interactions. Hyperhomocysteinemia might therefore influence the clinical history of IBD, including disease severity, susceptibility to particular enteric infections, and the risk for the development of colorectal cancer. In contrast, homocysteine metabolism does not seem to contribute to the greater risk of thrombosis in IBD subjects. Herein, we review the evidence linking homocysteine metabolism to the pathophysiology of IBD. Furthermore, we discuss the relevance of screening and treating folate and vitamin B(12) deficiencies in IBD subjects. Given the peculiar frequency of such deficiencies in IBD, normalizing vitamin levels should be an integral part of the management of these patients, especially those with active disease, history of intestinal resection, and/or treated with methotrexate.     

Labelling chemistry and characterization of [90Y/177Lu]-DOTA-ZHER2:342-3 Affibody molecule, a candidate agent for locoregional treatment of urinary bladder carcinoma

The direct instillation of radiolabelled conjugates in the urinary bladder is a promising path for the treatment of bladder carcinoma. The targeting of HER2/neu receptors expressed on the surface of many bladder carcinoma cells shows potential to be developed as a therapeutic strategy, and patients identified with a high risk of progression may benefit from adjuvant targeted radionuclide therapy. A phage-display selected Affibody molecule (Z(HER2:342)) which binds to HER2/neu with picomolar affinity, can be used for targeting HER2/neu-expressing bladder carcinomas. A DOTA-derivative of Z(HER2:342), designated as DOTA-Z(HER2:342)-3, is considered as a suitable targeting agent for therapy. The DOTA chelator provides stable labelling with radiometals, and the low molecular weight (7.2 kDa) of the DOTA-Z(HER2:342)-3 compound is expected to enable efficient tumor penetration. DOTA-Z(HER2:342)-3 was radiolabelled with 90Y and 177Lu in 1 M ammonium acetate buffer, at pH 5.5, and in the presence of ascorbic acid. Nearly quantitative labelling yields were achieved for both nuclides after 15 min of incubation at 60 degrees C. After chelation, the conjugates retained their capacity to specifically bind to HER2/neu-expressing SKOV-3 cells. The radiolabelled affibody conjugate (DOTA-Z(HER2:342)-3) demonstrated high antigen-binding capacity and good cellular retention. Biodistribution in normal mice demonstrated low uptake in all organs and tissues except for kidneys.     

Myoglobin plasma level related to muscle mass and fiber composition – a clinical marker of muscle wasting?

Progressive muscle wasting is a central feature of cancer-related cachexia and has been recognized as a determinant of poor prognosis and quality of life. However, until now, no easily assessable clinical marker exists that allows to predict or to track muscle wasting. The present study evaluated the potential of myoglobin (MG) plasma levels to indicate wasting of large locomotor muscles and, moreover, to reflect the loss of MG-rich fiber types, which are most relevant for daily performance. In 17 cancer-cachectic patients (weight loss 22%) and 27 age- and gender-matched healthy controls, we determined plasma levels of MG and creatine kinase (CK), maximal quadriceps muscle cross-sectional area (CSA) by magnetic resonance imaging, muscle morphology and fiber composition in biopsies from the vastus lateralis muscle, body cell mass (BCM) by impedance technique as well as maximal oxygen uptake (VO(2)max). In cachectic patients, plasma MG, muscle CSA, BCM, and VO(2)max were 30-35% below control levels. MG showed a significant positive correlation to total muscle CSA (r = 0.65, p < 0.001) and to the CSA fraction formed by type 1 and 2a fibers (r = 0.80, p < 0.001). However, when adjusted for body height and age by multiple regression, MG yielded a largely improved prediction of total CSA (multiple r = 0.83, p < 0.001) and of fiber type 1 and 2a CSA (multiple r = 0.89, p < 0.001). The correlations between CK and these muscle parameters were weaker, and elevated CK values were observed in 20% of control subjects despite a prior abstinence from exercise for 5 days. In conclusion, plasma MG, when adjusted for anthropometric parameters unaffected by weight, may be considered as a novel marker of muscle mass (CSA) indicating best the mass of MG-rich type 1 and 2a fibers as well as VO(2)max as an important functional readout. CK plasma levels appear to be less reliable because prolonged increases are observed in even subclinical myopathies or after exercise. Notably, cancer-related muscle wasting was not associated with increases in plasma MG or CK in this study.     

A magnetic resonance imaging-based prognostic scoring system to predict outcome in transplant-eligible patients with multiple myeloma

Diffuse and focal bone marrow infiltration patterns detected by magnetic resonance imaging have been shown to be of prognostic significance in all stages of monoclonal plasma cell disorders and have, therefore, been incorporated into the definition of the disease. The aim of this retrospective analysis was to develop a rapidly evaluable prognostic scoring system, incorporating the most significant information acquired from magnetic resonance imaging. Therefore, the impact of bone marrow infiltration patterns on progression-free and overall survival in 161 transplant-eligible myeloma patients was evaluated. Compared to salt and pepper/minimal diffuse infiltration, moderate/severe diffuse infiltration had a negative prognostic impact on both progression-free survival (P<0.001) and overall survival (P=0.003). More than 25 focal lesions on whole-body magnetic resonance imaging or more than seven on axial magnetic resonance imaging were associated with an adverse prognosis (progression-free survival: P=0.001/0.003 and overall survival: P=0.04/0.02). A magnetic resonance imaging-based prognostic scoring system, combining grouped diffuse and focal infiltration patterns, was formulated and is applicable to whole-body as well as axial magnetic resonance imaging. The score identified high-risk patients with median progression-free and overall survival of 23.4 and 55.9 months, respectively (whole-body-based). Multivariate analyses demonstrated that the magnetic resonance imaging-based prognostic score stage III (high-risk) and adverse cytogenetics are independent prognostic factors for both progression-free and overall survival (whole-body-based, progression-free survival: hazard ratio=3.65, P<0.001; overall survival: hazard ratio=5.19, P=0.005). In conclusion, we suggest a magnetic resonance imaging-based prognostic scoring system which is a robust, easy to assess and interpret parameter summarizing significant magnetic resonance imaging findings in transplant-eligible patients with multiple myeloma.