Characterization of natural killer cells in paired CSF and blood samples during neuroinflammation

Natural killer (NK) cells from paired CSF and blood samples of patients with multiple sclerosis (MS), other neuroinflammatory diseases (IND), and non-inflammatory neurological diseases (NIND) were characterized using flow cytometry. NK cell frequency in CSF was overall decreased compared to blood, particularly in MS patients. In contrast to blood NK cells, during neuroinflammation, CSF NK cells display an immature phenotype with bright expression of CD56 and CD27 and reduced CX3CR1 expression. Our findings suggest that, as for central memory T cells, CSF may represent an intermediary compartment for NK cell trafficking and differentiation before entering the CNS parenchyma.     

Aspirin Treatment and Outcomes After Percutaneous Coronary Intervention : Results of the ISAR-ASPI Registry

Background

Aspirin administration, as part of a dual antiplatelet treatment regimen, is essential for patients undergoing percutaneous coronary intervention (PCI). Although the correlation between high on-clopidogrel treatment platelet reactivity (HCPR) and clinical outcome is well established, data for high on-aspirin treatment platelet reactivity (HAPR) are conflicting.

Objectives

The aim of the ISAR-ASPI (Intracoronary Stenting and Antithrombotic Regimen—ASpirin and Platelet Inhibition) registry was to assess the value of HAPR as a possible prognostic biomarker in PCI-treated patients with regard to clinical outcome.

Methods

From February 2007 to May 2013, we identified 7,090 consecutive PCI-treated patients with measured on-aspirin treatment platelet aggregation values directly before PCI. Platelet function was assessed with a Multiplate analyzer. The primary endpoint was death or stent thrombosis (ST) at 1 year.

Results

The upper quintile of patients (n = 1,414), according to Multiplate measurements, was defined as the HAPR cohort. Compared with non-HAPR patients (n = 5,676), HAPR patients showed a significantly higher risk of death or ST at 1 year (6.2% vs. 3.7%, respectively; odds ratio [OR]: 1.78; 95% confidence interval [CI]: 1.39 to 2.27; p < 0.0001). HAPR was found to be an independent predictor of the primary outcome (adjusted hazard ratio [HR_adj]: 1.46; 95% CI: 1.12 to 1.89; p = 0.005).

Conclusions

HAPR, measured at the time point of the PCI, is associated with a higher risk for death or ST during the first year after PCI. Present data are in support of the addition of HAPR to a panel of prognostic biomarkers in PCI-treated patients.     

SLy2 controls the antibody response to pneumococcal vaccine through an IL‐5Rα‐dependent mechanism in B‐1 cells

The adaptor protein SLy2 (Src homology domain 3 lymphocyte protein 2) is located on human chromosome 21 and was reported to be among a group of genes amplified in Down's syndrome (DS) patients. DS patients characteristically show an impaired immunity to pneumococcal infections. However, molecular mechanisms linking gene amplifications with specific DS phenotypes remain elusive. To investigate the effect of SLy2 gene amplification on the mammalian immune system, we studied SLy2 overexpressing transgenic‐SLy2 (TG) mice. We found that baseline immunoglobulin M (IgM) levels as well as IgM responses following Pneumovax immunizations were reduced in TG mice. Moreover, B‐1 cells, the major natural IgM‐producing population in mice, were reduced in the peritoneal cavity of TG mice, while other immune cell compartments were unaltered. Mechanistically, SLy2 overexpression attenuated the expression of the IL‐5 receptor α chain on B‐1 cells, resulting in decreased B‐1 cell numbers and decreased differentiation into Ab‐secreting cells. Since B‐1 cells essentially contribute to immunity against Streptococcus pneumoniae, the present study provides a novel molecular link between SLy2 expression and pneumococcal‐specific IgM responses in vivo. These studies suggest that the adaptor protein SLy2 is a potential future target for immunomodulatory strategies for pneumococcal infections.     

Inflammation-Induced IL-6 Functions as a Natural Brake on Macrophages and Limits GN

IL-6 can mediate proinflammatory effects, and IL-6 receptor (IL-6R) blockade as a treatment for inflammatory diseases has entered clinical practice. However, opposing effects of IL-6 have been observed in models of GN. Although IL-6 is proinflammatory in murine lupus nephritis, protective effects have been observed for IL-6 in the nephrotoxic nephritis (NTN) model of acute crescentic GN. In light of the potential dangers of IL-6–directed treatment, we studied the mechanisms underlying the contradictory findings in GN. IL-6 can signal through the membrane-bound IL-6R, which is expressed only on hepatocytes and certain leukocytes (classic), or through the soluble IL-6R, which binds the ubiquitously expressed gp130 (alternative). Preemptive treatment of mice with anti-IL-6R or anti-IL-6 worsened NTN, whereas selective blockade of alternative IL-6 signaling by the fusion protein sgp130Fc did not. FACS analysis of mouse spleen cells revealed proinflammatory macrophages express the highest levels of IL-6Rα, and in vitro treatment with IL-6 blocked macrophage proliferation. Furthermore, proinflammatory macrophages were expanded during inflammation in IL-6^−/− mice. Late application of anti-IL-6 after establishment of adaptive nephritogenic immunity was sufficient to aggravate NTN within 2.5 days, a period when macrophages are active. Finally, NTN was aggravated in mice with macrophage-specific impairment of IL-6 classic signaling, coincident with enhanced macrophage proliferation and accumulation in the kidney. Our data thus reveal a novel mechanism in which IL-6–mediated dampening of macrophage activation protects tissues from overshooting immune responses. This finding has important implications for potential IL-6–directed therapies and supports the careful choice of recipient patients and timing.     

Towards elimination of mother-to-child transmission of HIV: performance of different models of care for initiating lifelong antiretroviral therapy for pregnant women in Malawi (Option B+)

Introduction

Malawi introduced a new strategy to improve the effectiveness of prevention of mother-to-child HIV transmission (PMTCT), the Option B+ strategy. We aimed to (i) describe how Option B+ is provided in health facilities in the South East Zone in Malawi, identifying the diverse approaches to service organization (the “model of care”) and (ii) explore associations between the “model of care” and health facility–level uptake and retention rates for pregnant women identified as HIV-positive at antenatal (ANC) clinics.

Methods

A health facility survey was conducted in all facilities providing PMTCT/antiretroviral therapy (ART) services in six of Malawi''s 28 districts to describe and compare Option B+ service delivery models. Associations of identified models with program performance were explored using facility cohort reports.

Results

Among 141 health facilities, four “models of care” were identified: A) facilities where newly identified HIV-positive women are initiated and followed on ART at the ANC clinic until delivery; B) facilities where newly identified HIV-positive women receive only the first dose of ART at the ANC clinic, and are referred to the ART clinic for follow-up; C) facilities where newly identified HIV-positive women are referred from ANC to the ART clinic for initiation and follow-up of ART; and D) facilities serving as ART referral sites (not providing ANC). The proportion of women tested for HIV during ANC was highest in facilities applying Model A and lowest in facilities applying Model B. The highest retention rates were reported in Model C and D facilities and lowest in Model B facilities. In multivariable analyses, health facility factors independently associated with uptake of HIV testing and counselling (HTC) in ANC were number of women per HTC counsellor, HIV test kit availability, and the “model of care” applied; factors independently associated with ART retention were district location, patient volume and the “model of care” applied.

Conclusions

A large variety exists in the way health facilities have integrated PMTCT Option B+ care into routine service delivery. This study showed that the “model of care” chosen is associated with uptake of HIV testing in ANC and retention in care on ART. Further patient-level research is needed to guide policy recommendations.     

Leukoreduction system chambers are an efficient,valid, and economic source of functional monocyte-derived dendritic cells and lymphocytes

The demand for human monocyte-derived dendritic cells (moDCs), as well as for primary human B and T lymphocytes for immunological research purposes has been increased in recent years. Classically, these monocytes are isolated from blood, leukapheresis products or buffy coats of healthy donors by plastic adherence of peripheral blood mononuclear cells (PBMCs), followed by stimulation with granulocyte macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-4, while lymphocytes are usually isolated from the non-adherent fraction (NAF) by magnetic cell sorting. However, donor-blood is a limited resource and not every blood bank offers leukapheresis products or buffy coats for laboratory use. Additionally, a leukapheresis is very expensive and also the generation/isolation of cells is time- and cost-intensive. To overcome some of these obstacles, we evaluated if low-cost leukoreduction system chambers (LRSCs), which arise after routine donor plateletpheresis procedures, and are usually discarded, would be an alternative and appropriate source of PBMCs to generate moDCs and to isolate lymphocytes. By analyzing the number and phenotype of immature and mature dendritic cells (DCs), as well as of B and T lymphocytes derived from LRSCs, we found all cells to be of high quantity and quality. Further investigations on DCs comprising transwell migration assays, allogeneic mixed lymphocyte reactions (MLR), cytokine secretion assays, and cytotoxic T cell induction assays revealed high migratory, as well as stimulatory capacity of these cells. In addition, DCs and T cells were efficiently electroporated with mRNA and showed characteristic cytokine production after co-culture, demonstrating LRSCs as an efficient, valid, and economic source for generation of moDCs and lymphocytes for research purposes.     

Toward Controlling the Formation,Degradation Behavior,and Properties of Hydrogels Synthesized by Aza‐Michael Reactions

The aza‐Michael reaction of amino‐functionalized polymers with acrylate and acrylamide crosslinkers for the formation of hydrogels is investigated. It is studied how far the reaction conditions (pH value, chemical structures of the compounds involved) influence the crosslinking and degradation rate of the gels. When crosslinking the polymer poly(1‐glycidylpiperazine), high pH values lead to fast crosslinking. Fast degradation of β‐aminoester crosslinks is observed when acrylate crosslinkers are used due to a neighboring group effect. With acrylamide crosslinkers, hydrolytically stable gels are formed, in which the shear moduli and swelling ratio can be adjusted and in which the extracts show no toxic effect on primary human fibroblasts, making them a promising material for biotechnological applications.

     

Localization of primary prostate cancer with dual-phase 18F-fluorocholine PET.

This study compared 18F-fluorocholine uptake in malignant and benign areas of the prostate at 2 time points to determine the suitability of delayed or dual-phase 18F-fluorocholine PET for localizing malignancy in the prostate gland. METHODS: Twenty-six men (15 newly diagnosed with prostate cancer, 2 with recurrent prostate cancer, 6 with no evidence of prostate cancer recurrence after treatment, and 3 with no history of prostate cancer) underwent dual-phase PET consisting of initial whole-body PET starting 7 min after injection of 3.3-4 MBq/kg of 18F-fluorocholine followed by 1-h delayed PET of the pelvis. Tracer uptake in the prostate on the initial and delayed images was measured on a sextant basis. Prostate biopsy or whole-prostate histologic examination after radical prostatectomy was used to classify a prostate sextant as a dominant malignant region or probable benign region. For each sextant, a retention index based on the measured maximum standardized uptake value (SUVmax) was calculated on the initial and delayed images. In 15 prostates with both benign and malignant sextants on histologic examination, a malignant-to-benign ratio of SUVmax was also calculated for each time point. RESULTS: A dominant malignant region was found in 17 subjects, and a probable benign region was found in 24 subjects. The mean SUVmax for dominant malignant regions increased significantly between initial and delayed scans, from 7.6 to 8.6 (mean retention index, +14%; 95% confidence interval, 6%-22%; P = 0.002). The mean SUVmax for probable benign regions decreased significantly between initial and delayed scans, from 4.8 to 3.9 (mean retention index, -17%; 95% confidence interval, -10% to -23%, P < 0.001). The mean malignant-to-benign ratio increased significantly, from 1.4 on the initial scan to 1.8 on the delayed scan (P = 0.003). The areas under the receiver operating characteristic curves for distinguishing dominant malignant regions from probable benign regions based on initial SUVmax, delayed SUVmax, and retention index were 0.81, 0.92, and 0.93, respectively. CONCLUSION: On dual-phase PET of the prostate, areas of malignancy consistently demonstrated stable or increasing 18F-fluorocholine uptake, whereas most areas containing benign tissue demonstrated decreasing uptake. Delayed or dual-phase imaging after injection of 18F-fluorocholine may improve the performance of 18F-fluorocholine PET for localizing malignant areas of the prostate.