Analyses of phenotypic and functional characteristics of CX3CR1-expressing natural killer cells

We previously demonstrated a correlation between the frequency of CX3CR1-expressing human natural killer (NK) cells and disease activity in multiple sclerosis and showed that CX3CR1(high) NK cells were more cytotoxic than their CX3CR1(neg/low) counterparts. Here we aimed to determine whether human NK cell fractions defined by CX3CR1 represent distinct subtypes. Phenotypic and functional NK cell analyses revealed that, distinct from CX3CR1(high), CX3CR1(neg/low) NK cells expressed high amounts of type 2 cytokines, proliferated robustly in response to interleukin-2 and promoted a strong up-regulation of the key co-stimulatory molecule CD40 on monocytes. Co-expression analyses of CX3CR1 and CD56 demonstrated the existence of different NK cell fractions based on the surface expression of these two surface markers, the CX3CR1(neg) CD56(bright), CX3CR1(neg) CD56(dim) and CX3CR1(high) CD56(dim) fractions. Additional investigations on the expression of NK cell receptors (KIR, NKG2A, NKp30 and NKp46) and the maturation markers CD27, CD62L and CD57 indicated that CX3CR1 expression of CD56(dim) discriminated between an intermediary CX3CR1(neg) CD56(dim) and fully mature CX3CR1(high) CD56(dim) NK cell fractions. Hence, CX3CR1 emerges as an additional differentiation marker that may link NK cell maturation with the ability to migrate to different organs including the central nervous system.     

Overexpression of PaParp encoding the poly(ADP-ribose) polymerase of Podospora anserina affects organismal aging

Poly(ADP-ribose) polymerases (PARPs) are a diverse group of proteins present in all multicellular eukaryotes. They catalyze the NAD(+)-dependent modification of proteins with poly(ADP-ribose). Poly(ADP-ribosyl)ation plays a key role in a plethora of processes including DNA repair, tumor progression and aging. Here we report that PaPARP, the single protein with a PARP catalytic domain, in the fungal aging model Podospora anserina, indeed displays a NAD(+)-dependent poly(ADP-ribose) polymerase activity. While unable to select a PaParp deletion strain, we succeeded in the generation of PaParp overexpressors. Biochemically these strains are characterized by reduced mitochondrial membrane potential and a lowered ATP content. They show an increased sensitivity against different stressors including the DNA damaging agent phleomycin, the reactive oxygen generator paraquat, and the apoptosis inducer farnesol. PaParp overexpressors are impaired in growth, in pigmentation and fertility, and have a shortened lifespan. Our results demonstrate the relevance of poly(ADP-ribose) metabolism for aging and development in P. anserina. With a single PARP this metabolism is less complex than in higher eukaryotes and thus P. anserina appears to be a promising system to connect basic PARP functions with the well established network of pathways relevant for organismal aging.     

Induction of organ-selective CD4+ regulatory T cell homing

Compelling evidence suggests that Foxp3⁺CD25⁺CD4⁺ Treg play a fundamental role in immunoregulation. We have previously demonstrated that Treg have to enter peripheral tissues to suppress ongoing inflammation. However, relatively little is known about how Treg acquire the expression of homing receptors required for tissue‐ or inflammation‐specific migration. Migratory properties of conventional naïve T cells are shaped by the tissue microenvironment and organ‐specific dendritic cells during priming. Here, we show that this basic concept also holds true for CD25⁺CD4⁺ Treg: Priming of Treg within peripheral LN led to the expression of selectin ligands, which facilitate migration into inflamed skin, whereas activation within mesenteric LN led to induction of the integrin α₄β₇, which is required for migration into mucosal tissues. Furthermore, we could establish in vitro culture systems containing either dendritic cells from mesenteric and peripheral LN, or retinoic acid and IL‐12 as polarizing compounds to induce mucosa‐ and skin‐seeking Treg, respectively. Together, our results demonstrate that Treg, similarly to conventional T cells, can be configured with organ‐selective homing properties allowing efficient targeting into distinct tissues.     

The role of the octarepeat region in neuroprotective function of the cellular prion protein

Structural alterations of the cellular prion protein (PrP(C)) seem to be the core of the pathogenesis of prion diseases. However, the physiological function of PrP(C )remains an enigma. Cell culture experiments have indicated that PrP(C) and in particular its N-terminal octarepeat region together with the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathways have a fundamental involvement in neuroprotection and oxidative stress reactions. We used wild-type mice, PrP knockout (Prnp(-/-)) animals and transgenic mice that lack the octarepeat region (C4/-) and subjected them to controlled ischemia. We identified an increased cleavage and synthesis of PrP(C) in ischemic brain areas of wild-type mice compared with sham controls. The infarct size in Prnp(-/-) animals was increased threefold when compared with wild-type mice. The infarct size in C4/- animals was identical to Prnp(-/-) mice, that is, around three times larger than in wild-type mice. We showed that the PrP in C4/- mice does not functionally rescue the Prnp(-/-) phenotype; furthermore it is unable to undergo beta cleavage, although an increased amount of C1 fragments was found in ischemic brain areas compared with sham controls. We demonstrated that the N-terminal octarepeat region has a lead function in PrP(C) physiology and neuroprotection against oxidative stress in vivo.     

Colonic motility diagnosis based on colonic pressure

Manometry of the alimentary tract is a valuable and widely used means to evaluate and diagnose the function of the alimentary tract. However, the measurement can be inconvenient due to the invasive method used, and the many factors affecting results. Research on colonic pressure data is even more insufficient. This paper deals with colonic pressure data via an improved method ensuring that pressure data of the whole colon is available. The data is analysed based on the learning vector quantization (LVQ) method. Testing results show that this method distinguishes the normal data and the abnormal data, consistently with the original diagnoses. This method can serve as an assistant diagnosis of colonic motility and contributes to further research on colonic motility based on pressure data.     

Dedicated pinhole SPECT of intestinal neutrophil recruitment in a mouse model of dextran sulfate sodium-induced colitis.

Evaluating the efficacy of therapy in experimental inflammatory bowel disease (IBD) requires information about inflammatory activity in bowel segments or leukocyte recruitment and about kinetics in the follow-up of treatment. This study evaluated a noninvasive scintigraphic technique able to assess neutrophil trafficking in a mouse model of dextran sulfate sodium (DSS)-induced colitis. METHODS: Groups of 4 BALB/c mice were assessed at baseline and after 1, 3, 5, and 8 d of treatment with DSS. Donor neutrophils were harvested by rinsing of the peritoneal cavity with phosphate-buffered saline 5 h after intraperitoneal injection of proteose peptone contained in phosphate-buffered saline and labeled with freshly prepared (99m)Tc-hexamethylpropylene amine oxime (HMPAO). Pinhole SPECT of the abdomen was performed 1 h after reinjection of 50 MBq of labeled neutrophils. In addition, the severity of inflammation was determined by histologic examination. The possibilities of the technique were illustrated by scintigraphic assessment of neutrophil trafficking with and without blocking of neutrophil migration by a CD97 monoclonal antibody in mice with DSS-induced colitis. RESULTS: Colonic uptake of (99m)Tc-HMPAO neutrophils was determined with dedicated animal pinhole SPECT in mice with DSS-induced colitis and correlated well with histologic findings (R = 0.81) and wet colon weight (R = 0.87) and moderately with clinical weight loss (R = 0.62). The neutrophil uptake ratio was reduced significantly (P < 0.01) by blocking of neutrophil migration capacity with the CD97 antibody. CONCLUSION: Animal pinhole SPECT can be used to study inflammatory activity and neutrophil recruitment in vivo in experimental colitis.     

Immunologic status of hemophilia patients treated with cryoprecipitate or lyophilized concentrate

We evaluated 37 patients with moderate or severe hemophilia A and six patients with severe factor IX deficiency for clinical or laboratory evidence of immune abnormalities. Patients were assigned to one of four groups according to the type of clotting factor replacement. Twenty patients had received only cryoprecipitate during the two years preceding the evaluation (group I); 11 additional patients were treated predominantly with cryoprecipitate but had also received up to nine bottles of factor VIII concentrate (group II); six patients received factor VIII concentrate (group III); six patients received factor IX concentrate (group IV). There was no clinical or laboratory evidence of immunodeficiency among the 43 patients. The mean absolute number of Th cells was normal in all patient groups, but the mean absolute number of Ts cells was increased compared with controls, both in patients treated with cryoprecipitate and in patients treated with factor VIII or factor IX concentrate. There was no correlation between the Th/Ts ratio and patient age, alanine aminotransferase level, hepatitis serology, in vitro lymphocyte function, or amount of clotting factor administered. Our observations demonstrate that the volunteer or commercial origin of clotting factor replacement cannot fully explain the alterations in lymphocyte subset distribution previously described in patients with hemophilia A.     

Relationship between depression,weight, and patient satisfaction 2 years after bariatric surgery

BackgroundFindings regarding longer term symptoms of depression and the impact of depression on outcomes such as weight loss and patient satisfaction, are mixed or lacking.ObjectivesThis study sought to understand the relationship between depression, weight loss, and patient satisfaction in the two years after bariatric surgery.SettingThis study used data from a multi-institutional, statewide quality improvement collaborative of 45 different bariatric surgery sites.MethodsParticipants included patients (N = 1991) who underwent Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) between 2015–2018. Participants self-reported symptoms of depression (Patient Health Questionnaire-8 [PHQ-8]), satisfaction with surgery, and weight presurgery and 1 year and 2 years postsurgery.ResultsCompared to presurgery, fewer patients’ PHQ-8 scores indicated clinically significant depression (PHQ-8≥10) at 1 year (P < .001; 14.3% versus 5.1%) and 2 years postsurgery (P < .0001; 8.7%). There was a significant increase in the prevalence of clinical depression from the first to second year postsurgery (P < .0001; 5.1% versus 8.7%). Higher PHQ-8 at baseline was related to less weight loss (%Total Weight Loss [%TWL] and %Excess Weight Loss [%EWL]) at 1 year postsurgery (P < .001), with a trend toward statistical significance at 2 years (P = .06). Postoperative depression was related to lower %TWL and %EWL, and less reduction in body mass index (BMI) at 1 year (P < .001) and 2 years (P < .0001). Baseline and postoperative depression were associated with lower patient satisfaction at both postoperative time points.ConclusionsThis study suggests improvements in depression up to 2 years postbariatric surgery, although it appears that the prevalence of depression increases after the first year. Depression, both pre- and postbariatric surgery, may impact weight loss and patient satisfaction.