Culture of Human Monocyte-Derived Macrophages

The study of human macrophages is often hampered by access to tissue and inability of this cell type to survive in vitro following isolation. The culture of human monocyte-derived macrophages (MDMs) represents a tool to study macrophages, with monocytes known to give rise to tissue macrophages influenced by certain environmental cues. Here we describe a method of culturing monocyte-derived macrophages from CD14+ blood monocytes and polarization toward different macrophage phenotypes.

Accuracy of co-morbidity data in patients undergoing abdominal wall hernia repair: a retrospective study

OBJECTIVES

To determine the baseline accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of routinely collected co-morbidity data in patients undergoing abdominal wall hernia repair.

METHODS

All patients aged > 18 who underwent umbilical, para-umbilical, inguinal or incisional hernia repair between 1 January 2015 and 1 November 2016 were identified. All parts of the clinical notes were searched for co-morbidities by two authors independently. The following co-morbidities were considered: hypertension, ischaemic heart disease (IHD), diabetes, asthma, chronic obstructive pulmonary disease (COPD), cerebrovascular disease (CVD), chronic kidney disease (CKD), hypercholesterolemia, obesity and smoking. The co-morbidities data from clinical notes were compared with corresponding data in hospital episode statistics (HES) database to calculate accuracy, sensitivity, specificity, PPV and NPV of HES codes for co-morbidities. To assess the agreement between clinical notes and HES data, we also calculated Cohen's Kappa index value as a more robust measure of agreement.

RESULTS

Overall, 346 patients comprising 3460 co-morbidity codes were included in the study. The overall accuracy of HES codes for all co-morbidities was 77% (Kappa: 0.13). When calculated separately for each co-morbidity, the accuracy was 72% (Kappa: 0.113) for hypertension, 82% (Kappa: 0.232) for IHD, 85% (Kappa: 0.203) for diabetes, 86% (Kappa: 0.287) for asthma, 91% (Kappa: 0.339) for COPD, 92% (Kappa: 0.374) for CVD, 94% (Kappa: 0.424) for CKD, 74% (Kappa: 0.074) for hypercholesterolemia, 71% (Kappa: 0.66) for obesity and 24% (Kappa: 0.005) for smoking. The overall sensitivity, specificity, PPV and NPV of HES codes were 9, 100, 100, and 77%, respectively. The results were consistent when individual co-morbidities were analyzed separately.

CONCLUSIONS

Our results demonstrated that HES co-morbidity codes in patients undergoing abdominal wall hernia repair are specific with good positive predictive value; however, they have substandard accuracy, sensitivity, and negative predictive value. The presence of a relatively large number of false negative or missed cases in HES database explains our findings. Better documentation of co-morbidities in admission clerking proforma may help to improve the quality of source documents for coders, which in turn may improve the accuracy of coding.

Inflammatory cues enhance TGFβ activation by distinct subsets of human intestinal dendritic cells via integrin αvβ8

Regulation of intestinal T-cell responses is crucial for immune homeostasis and prevention of inflammatory bowel disease (IBD). A vital cytokine in regulating intestinal T cells is transforming growth factor-β (TGFβ), which is secreted by cells as a latent complex that requires activation to function. However, how TGFβ activation is regulated in the human intestine, and how such pathways are altered in IBD is completely unknown. Here we show that a key activator of TGFβ, integrin αvβ8, is highly expressed on human intestinal dendritic cells (DCs), specifically on the CD1c⁺ but not the CD141⁺ intestinal DC subset. Expression was significantly upregulated on intestinal DC from IBD patients, indicating that inflammatory signals may upregulate expression of this key TGFβ-activating molecule. Indeed, we found that the Toll-like receptor 4 ligand lipopolysaccharide upregulates integrin αvβ8 expression and TGFβ activation by human DC. We also show that DC expression of integrin αvβ8 enhanced induction of FOXP3 in CD4⁺ T cells, suggesting functional importance of integrin αvβ8 expression by human DC. These results show that microbial signals enhance the TGFβ-activating ability of human DC via regulation of integrin αvβ8 expression, and that intestinal inflammation may drive this pathway in patients with IBD.

Regulation of Innate and Adaptive Immunity by TGFβ

Immune regulation by cytokines is crucial in maintaining immune homeostasis, promoting responses to infection, resolving inflammation, and promoting immunological memory. Additionally, cytokine responses drive pathology in immune-mediated disease. A crucial cytokine in the regulation of all aspects of an immune response is transforming growth factor beta (TGFβ). Although best known as a crucial regulator of T cell responses, TGFβ plays a vital role in regulating responses mediated by virtually every innate and adaptive immune cell, including dendritic cells, B cells, NK cells, innate lymphoid cells, and granulocytes. Here, we review our current knowledge of how TGFβ regulates the immune system, highlighting the multifunctional nature of TGFβ and how its function can change depending on location and context of action.

Size of testes, ovaries, uterus and breast buds by ultrasound in healthy full-term neonates ages 0-3 days

BACKGROUND

Hormonally sensitive organs in the neonate can change size within days of birth as circulating maternal estrogen wanes. Although several reports document the size of these organs through infancy, few focus attention on the near-birth period. Clinical and research evaluation of hormonal and genitourinary disorders would benefit from reference size standards.

OBJECTIVE

We describe the size of the uterus, ovaries, testes and breast buds in healthy term neonates.

MATERIALS AND METHODS

As part of the Infant Feeding and Early Development (IFED) study, we sonographically measured the largest diameter of these organs in sagittal, transverse and anterior-posterior planes for 194 female and 204 male newborns up to 3 days old. We calculated mean, median and percentiles for longest axis length and for volume calculated from measured diameters. We evaluated size differences by laterality, gender and race and compared our observations against published values.

RESULTS

Mean length and mean volume were as follows: uterus, 4.2 cm and 10.0 cm³; ovary, 1.0 cm and 0.2 cm³; testis, 1.1 cm and 0.3 cm³ (0.4 cm³ Lambert volume); female breast bud, 1.2 cm and 0.7 cm³; male breast bud, 1.1 cm and 0.6 cm³. Breast buds were larger in females than males. Laterality differences were typically below the precision of clinical measurement. No significant race differences were detected.

CONCLUSION

Using data from our large cohort together with published values, we provide guidelines for evaluating the size of reproductive organs within the first 3 days of age. Discrepancies between our results and published values are likely attributable to technique.

Immune Cell Profiling of IFN-λ Response Shows pDCs Express Highest Level of IFN-λR1 and Are Directly Responsive via the JAK-STAT Pathway

The interferon lambda (IFN-λ) cytokines have well-known antiviral properties, yet their contribution to immune regulation is not well understood. Epithelial cells represent the major target cell of IFN-λ; peripheral blood mononuclear cells are generally considered nonresponsive, with the exception of plasmacytoid dendritic cells (pDCs). In this study we aimed to define the potential for discrete subpopulations of cells to directly respond to IFN-λ. Analysis of peripheral blood leukocytes reveals that, while pDCs uniformly express the highest levels of IFN-λ receptor, a small proportion of B cells and monocytes also express the receptor. Nevertheless, B cells and monocytes respond poorly to IFN-λ stimulation in vitro, with minimal STAT phosphorylation and interferon-stimulated gene (ISG) induction observed. We confirm that pDCs respond to IFN-λ in vitro, upregulating their expression of pSTAT1, pSTAT3, and pSTAT5. However, we found that pDCs do not upregulate pSTAT6 in response to IFN-λ treatment. Our results highlight unique aspects of the response to IFN-λ and confirm that while the IFN-λ receptor is expressed by a small proportion of several different circulating immune cell lineages, under normal conditions only pDCs respond to IFN-λ stimulation with robust STAT phosphorylation and ISG induction. The difference in STAT6 responsiveness of pDCs to type I and type III interferons may help explain the divergence in their biological activities.

The integrin αvβ8 promotes activation of TGFβ by human peripheral monocyte and intestinal macrophage populations

Transforming growth factor beta (TGFβ) plays a key role in maintaining immune homeostasis, both preventing inflammation and promoting tissue repair. The cytokine is secreted as an inactive complex, with the function of TGFβ tightly regulated at the level of its activation. Our previous work in mice has demonstrated a crucial role for an integrin, αvβ8, in activation of TGFβ in the immune system. This pathway appears especially important in the intestine, with important functions in regulating T-cell response via integrin αvβ8 expression in dendritic cells and regulatory T-cells. However, how TGFβ is activated to regulate the human immune system is poorly understood. Here, we show that, in humans, integrin αvβ8 is highly expressed on blood monocytes, which promotes activation of TGFβ by these cells. When monocytes are differentiated to macrophages, high integrin β8 expression and TGFβ-activating function is observed on the more tolerogenic (M2-like) macrophages versus inflammatory (M1-like) macrophages. In both monocytes and macrophages, expression of β8 is upregulated by specific bacterial TLR ligands, suggesting that stimulation of the cells may promote their ability to activate TGFβ. In addition to peripheral immune cells, intestinal lamina propria mononuclear cells express high levels of integrin αvβ8, with increased levels seen in patients with inflammatory bowel disease. Highest levels of integrin αvβ8 are seen on a population of CD14+CD33+CD64+ cells, corresponding to intestinal macrophages. Thus, our data suggest that expression of integrin αvβ8 on monocytes may play an important role in the induction and function of anti-inflammatory macrophages in the intestine via TGFβ activation.

Integrin αvβ8-Mediated TGF-β Activation by Effector Regulatory T Cells Is Essential for Suppression of T-Cell-Mediated Inflammation

Regulatory T (Treg) cells play a pivotal role in suppressing self-harmful T cell responses, but how Treg cells mediate suppression to maintain immune homeostasis and limit responses during inflammation is unclear. Here we show that effector Treg cells express high amounts of the integrin αvβ8, which enables them to activate latent transforming growth factor-β (TGF-β). Treg-cell-specific deletion of integrin αvβ8 did not result in a spontaneous inflammatory phenotype, suggesting that this pathway is not important in Treg-cell-mediated maintenance of immune homeostasis. However, Treg cells lacking expression of integrin αvβ8 were unable to suppress pathogenic T cell responses during active inflammation. Thus, our results identify a mechanism by which Treg cells suppress exuberant immune responses, highlighting a key role for effector Treg-cell-mediated activation of latent TGF-β in suppression of self-harmful T cell responses during active inflammation.

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Human and mouse effector Treg cells express functional TGF-β-activating integrin αvβ8

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Treg cell integrin αvβ8-mediated TGF-β activation is not needed for T cell homeostasis

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Integrin αvβ8 expression by Treg cells suppresses active inflammation

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Pathway could be targeted to promote Treg-cell-mediated suppression of inflammation

Integrin αvβ8-mediated TGFβ activation by effector regulatory T cells is essential for suppression of T cell-mediated inflammation (CAM1P.150)

Foxp3+ regulatory T-cells (Tregs) play a pivotal role in suppressing self-harmful T-cell responses to prevent inflammatory disease. An important cytokine in the development and function of Tregs is TGFβ, a latent cytokine that must be activated to function. Compelling evidence suggests that T-cells need to respond to TGFβ in order for Treg-mediated suppression to occur. Yet, how TGFβ is regulated to promote this suppression is poorly understood. We now show that both mouse and human Tregs have high expression of the TGFβ-activating integrin αvβ8, which enables these cells to activate high levels of latent TGFβ. However, deletion of integrin αvβ8 expression from Tregs resulted in no overt phenotype at rest, indicating that the integrin plays little role in controlling immunity during homeostasis. Strikingly, we find that integrin αvβ8 expression and function is highly upregulated on an activated/effector Treg subset marked by KLRG1, and that Tregs lacking expression of integrin αvβ8 were unable to function as suppressive cells during models of colitis and delayed type hypersensitivity in vivo. Thus, we have uncovered an essential mechanism by which effector Tregs suppress T-cells during inflammation, highlighting a key role for Treg-mediated activation of latent TGFβ in suppression of self-harmful T-cell responses. Our work therefore highlights a novel pathway that could be therapeutically targeted to treat inflammatory disease.

Treatment outcome for adolescents abusing alcohol and cannabis: how many 'reliably improve'?

Alcohol and cannabis are the primary substances contributing to referrals of adolescents to substance abuse treatment services. Their outcome has not been examined in Ireland. A three month follow-up was conducted in an outpatient adolescent treatment program. We followed up 35 high risk users of alcohol and 55 high risk users of cannabis. Although the high risk drinkers achieved a significant reduction in median number of days drinking (p = 0.004), only four (11 %) were abstinent at follow up. A further five (14%) achieved a reliable reduction in days of drinking. The high risk cannabis users demonstrated a significant drop in median days of use (p < 0.001), although only six (11%) were abstinent at follow up. A further 20 (36%) achieved a reliable reduction in days of use. Calculation of reliable change allows examination of outcomes which fall short of the elusive goal of abstinence.