Objective: Reduced numbers of regulatory T (T reg ) cells have been observed in visceral adipose tissue of obese mice and humans. However, it is unknown whether human obesity affects circulating Treg cells and whether their number is associated with markers of systemic inflammation or glucose intolerance. Design and Methods: Peripheral blood mononuclear cells were isolated from venous blood of obese (BMI ! 27 kg/m 2 ; n ¼ 30) and nonobese (BMI ! 27 kg/m 2 ; n ¼ 13) individuals and analyzed using flow cytometry for the expression of CD4, CD25, and Foxp3. Results: Reduced circulating T reg -cell numbers were detected in obese compared with nonobese study participants (P ¼ 0.038). Circulating CD4 þ CD25 þ CD127 À Foxp3 T reg cells inversely correlated with body weight (P ¼ 0.009), BMI (P ¼ 0.004) and plasma leptin levels (P ¼ 0.004) and were reduced in subjects with hsCRP ! 3.0 mg/L (P ¼ 0.034) or HbA1c ! 5.5% (P < 0.005). Receiver operating characteristic curve analysis revealed a cutoff of circulating Treg cells < 1.06% to be predictive for hsCRP levels ! 3.0 mg/L, and logistic regression showed that the risk of having hsCRP levels ! 3.0 mg/L was increased 9.6-fold (P ¼ 0.008), if T reg cells were below this threshold. The T reg cutoff for HbA1c levels ! 5.5% was 0.73%, and this cutoff also predicted an increased risk of having elevated levels of both hsCRP and HbA1c, if only obese subjects were examined. Conclusion: Our findings thus reveal an association between circulating T reg cells and measures of adiposity, inflammation, and glucose intolerance. Although further prospective studies are needed, we present data suggesting that the determination of T reg cells might be useful to identify obese subjects at increased risk of developing cardiovascular and/or metabolic complications.

Human defensins are natural peptide antibiotics. On the basis of the position and bonding of six conserved cysteine residues, they are divided into two families, designated α- and β-defensins. Human α-defensins are expressed predominantly in neutrophils (human neutrophil peptides (HNP) 1–4) or intestinal Paneth cells (human defensins (HD) 5 and 6). Although α-defensins have been implicated in the pathogenesis of inflammatory bowel disease, their immunomodulatory functions are poorly understood. In the present study, HNP-1, HNP-3, and HD5 were found to be potent chemotaxins for macrophages but not dendritic cells using Gαi proteins and MAPK as signal transducers. α-Defensins were also chemoattractive for the human mast cell line HMC-1 but lacked, in contrast to β-defensins, the ability to induce intracellular calcium fluxes. Furthermore, HNP-1, HNP-3, and HD5 comparably mobilized naive as well as memory T lymphocytes. Using the protein kinase C (PKC) inhibitors GF109 and Gö6976, we observed a PKC-independent functional desensitization to occur between human α-defensins, which suggests a common receptor for HNP-1, HNP-3, and HD5 on immune cells. This α-defensin receptor was subject to heterologous desensitization by the PKC activator PMA and to PKC-dependent cross-desensitization by human β-defensins. Conversely, α-defensins desensitized β-defensin-mediated migration of immune cells in a PKC-dependent manner, suggesting unique receptors for both defensin families. Taken together, our observations indicate that chemoattraction of macrophages, T lymphocytes, and mast cells represents an immunomodulatory function which is evolutionarily conserved within the human α-defensin family and tightly regulated by β-defensins.

b-Defensins are natural peptide antibiotics whose immunomodulatory functions are poorly understood. In the present study, macrophages were found to migrate to human b-defensins (HBD)-1 to -4 using Ga i proteins as well as MAPK ERK, p38 and JNK as signal transducers. In addition, mast cells responded to HBD-1 to -4 with calcium fluxes as well as chemotaxis, which increased upon stimulation with IgE plus antigen or ionomycin. In contrast, human b-defensins were unable to induce migration of memory lymphocytes and dendritic cells (DC). Similar to HBD, the murine b-defensin (mBD)-8 mobilized macrophages and lacked the ability to recruit memory T cells. These findings were unexpected as CCR6 on memory T cells and DC has been previously observed to be a receptor for human b-defensins. In support of our findings, however, RBL-2H3 as well as 300.19 cells stably expressing CCR6 proved to be unresponsive to HBD-2 and -3. Intriguingly, our observation of a PKC-independent homologous desensitization between HBD-1 to -4 suggests a common receptor for HBD. In summary, chemoattraction of macrophages and mast cells is evolutionary conserved within the b-defensin family despite a considerable sequence variation and distinct antimicrobial activities. However, CCR6 is not a functional receptor for b-defensins.

The PGAS allows identification of marker-associated clinical/biological traits. Current cognitive performance in schizophrenic patients is modified by CPLX2 variants modulating posttranscriptional gene expression.

The use of leukocyte-depleted blood components has become the standard therapy for multiply transfused patients during the past few years, as a measure to reduce the frequency of alloimmunization and refractoriness. We assessed frequency and causes of refractoriness, defined as a repeated 24-h post-transfusion platelet count below 20,000/microliters, in 145 consecutive patients who received three or more single-donor platelet concentrates during a 1-year period. Flow-cytometric detection of anti-platelet antibodies and a glycoprotein-specific ELISA were applied for the diagnosis of alloimmunization. Forty patients (27.6%) had at least one episode of refractoriness. In 25 of these 40 patients (62.5%), nonimmune factors (fever, sepsis, coagulopathy, splenomegaly) alone were the cause. In 15 refractory patients alloantibodies were detected. In seven patients (17.5%), alloimmunization alone caused an inadequate transfusion response, while in eight refractory patients (20.0%) alloimmunization and fever or sepsis were present. HLA antibodies were detected in 17 patients (11.7%); three patients (2%) had platelet-specific antibodies in addition to HLA antibodies; in two patients panreactive platelet antibodies were detectable. All 17 patients had a history of previous transfusions or pregnancy. We did not observe primary immunization in patients transfused exclusively with filtered (leukodepleted) blood products. Our data suggest that alloimmunization in patients with a negative risk history can be prevented by the exclusive use of leukodepleted blood components.