CD14 Influences Host Immune Responses and Alternative Activation of Macrophages during Schistosoma mansoni Infection

Antigen-presenting cell (APC) plasticity is critical for controlling inflammation in metabolic diseases and infections. The roles that pattern recognition receptors (PRRs) play in regulating APC phenotypes are just now being defined. We evaluated the expression of PRRs on APCs in mice infected with the helminth parasite Schistosoma mansoni and observed an upregulation of CD14 expression on macrophages. Schistosome-infected Cd14^−/− mice showed significantly increased alternative activation of (M2) macrophages in the livers compared to infected wild-type (wt) mice. In addition, splenocytes from infected Cd14^−/− mice exhibited increased production of CD4⁺-specific interleukin-4 (IL-4), IL-5, and IL-13 and CD4⁺Foxp3⁺IL-10⁺ regulatory T cells compared to cells from infected wt mice. S. mansoni-infected Cd14^−/− mice also presented with smaller liver egg granulomas associated with increased collagen deposition compared to granulomas in infected wt mice. The highest expression of CD14 was found on liver macrophages in infected mice. To determine if the Cd14^−/− phenotype was in part due to increased M2 macrophages, we adoptively transferred wt macrophages into Cd14^−/− mice and normalized the M2 and CD4⁺ Th cell balance close to that observed in infected wt mice. Finally, we demonstrated that CD14 regulates STAT6 activation, as Cd14^−/− mice had increased STAT6 activation in vivo, suggesting that lack of CD14 impacts the IL-4Rα-STAT6 pathway, altering macrophage polarization during parasite infection. Collectively, these data identify a previously unrecognized role for CD14 in regulating macrophage plasticity and CD4⁺ T cell biasing during helminth infection.     

Plasmacytoid DC promote priming of autoimmune Th17 cells and EAE

EAE, an animal model for MS, is a Th17 and Th1‐cell‐mediated autoimmune disease, but the mechanisms leading to priming of encephalitogenic T cells in autoimmune neuroinflammation are poorly understood. To investigate the role of plasmacytoid DC (pDC) in the initiation of autoimmune Th17‐ and Th1‐cell responses and EAE, we depleted pDC with anti‐pDC Ag‐1 (anti‐PDCA1) mAb prior to immunization of C57BL/6 mice with myelin oligodendrocyte glycoprotein (MOG). pDC‐depleted mice developed less severe clinical and histopathological signs of EAE than control mice, which demonstrates a promoting role for pDC in the initiation of EAE. The levels of type I IFN were much lower in the sera from anti‐PDCA1‐treated mice. However, neutralization of type I IFN ameliorated the early phase of EAE but did not alter the severity of disease. Thus, only a minor part of the EAE‐promoting effect of pDC appears to be mediated by IFN‐α/β secretion. The numbers of MOG‐specific Th17 cells, but not Th1 cells, were lower in spleen from anti‐PDCA1‐treated mice compared with controls. In contrast, pDC depletion a week after MOG immunization resulted in more severe clinical signs of EAE. In conclusion, we demonstrate that pDC promote initiation of MOG‐induced Th17‐cell responses and EAE.     

Cytokines as genetic modifiers in K5–/– mice and in human epidermolysis bullosa simplex

Epidermolysis bullosa simplex (EBS) is a skin disorder caused by fully‐penetrant mutations in the keratin genes KRT5 and KRT14, leading to extensive cytolysis and cell fragility of basal keratinocytes. EBS is subject to environmental conditions and displays high intra‐ and interfamilial variability, suggesting modifying loci. Here, we demonstrate that upregulation of certain cytokines accompanies mutations in keratin 5 (K5) but not in keratin 14 (K14). We find for the first time that cytokines macrophage chemotactic protein (MCP)‐1/[chemokine (C‐C motif) ligand 2] (CCL2), macrophage inflammatory protein (MIP)‐3β/CCL19 and MIP‐3α/CCL20, all regulated by nuclear factor kappa B (NFκB) and involved in the recruitment, maturation, and migration of Langerhans cells (LCs) in the epidermis, are upregulated in the skin of K5^–/–, but not of K14^–/– mice. In neonatal K5^–/– epidermis, the number of LCs was increased two‐fold. At the same time, tumor necrosis factor alpha (TNFα) remained unaltered, demonstrating the specificity of that process. Most remarkably, enhanced LC recruitment within the epidermis was found in five EBS patients carrying mutations in the KRT5 gene but not in EBS patients with KRT14 gene mutations. In agreement with the NFκB‐dependent regulation of these cytokines, we found a decrease in p120‐catenin in the basal epidermis of K5^–/– mice. These data provide the first explanation for distinct, keratin‐type‐specific genotype–phenotype correlations in EBS and represent a rationale to investigate gene loci affecting skin pathology in EBS. Hum Mutat 0, 1–10, 2009. © 2009 Wiley‐Liss, Inc.     

Genomic variation in a global village: Report of the 10th annual Human Genome Variation Meeting 2008

The Centre for Applied Genomics of the Hospital for Sick Children and the University of Toronto hosted the 10th Human Genome Variation (HGV) Meeting in Toronto, Canada, in October 2008, welcoming about 240 registrants from 34 countries. During the 3 days of plenary workshops, keynote address, and poster sessions, a strong cross‐disciplinary trend was evident, integrating expertise from technology and computation, through biology and medicine, to ethics and law. Single nucleotide polymorphisms (SNPs) as well as the larger copy number variants (CNVs) are recognized by ever‐improving array and next‐generation sequencing technologies, and the data are being incorporated into studies that are increasingly genome‐wide as well as global in scope. A greater challenge is to convert data to information, through databases, and to use the information for greater understanding of human variation. In the wake of publications of the first individual genome sequences, an inaugural public forum provided the opportunity to debate whether we are ready for personalized medicine through direct‐to‐consumer testing. The HGV meetings foster collaboration, and fruits of the interactions from 2008 are anticipated for the 11th annual meeting in September 2009. Hum Mutat 30:1–5, 2009. © 2009 Wiley‐Liss, Inc.     

A randomized intervention since infancy to reduce intake of saturated fat: calorie (energy) and nutrient intakes up to the age of 10 years in the Special Turku Coronary Risk Factor Intervention Project

OBJECTIVE: To evaluate the longitudinal impact of dietary counseling on children's nutrient intake. DESIGN: A prospective, randomized, clinical trial. PARTICIPANTS: Children were recruited to the study between December 1, 1989, and May 30, 1992. At the age of 7 months, children were randomized to the intervention group (n = 540) or the control group (n = 522) and were followed up until the age of 10 years.Intervention Families in the intervention group have, since randomization, received regularly individualized counseling about how to modify the quality and quantity of fat in the child's diet, the goal being an unsaturated-saturated fat ratio of 2:1. MAIN OUTCOME MEASURES: Nutrient intakes between the ages of 4 and 10 years based on annual 4-day food records. RESULTS: The fat intake of the intervention children was constantly around 30% of the calorie (energy) intake, while that of the control children was 2 to 3 calorie percentage units higher (P<.001). The intervention children received 2 to 3 calorie percentage units less saturated fats and 0.5 to 1.0 calorie percentage unit more polyunsaturated fats than the control children (P<.001 for both). However, neither group reached the 2:1 goal set for the unsaturated-saturated fatty acid ratio. The vitamin and mineral intakes of the intervention and control children closely resembled each other despite the marked differences in fat intake. CONCLUSION: Individualized, biannually given, fat intake-focused dietary counseling that began at the child's age of 8 months continued to influence favorably the diet of 4- to 10-year-old intervention children without disadvantageous dietary effects, but the 2:1 goal for unsaturated-saturated fat ratio was not reached.     

Accuracy of axillary staging using sentinel node biopsy or diagnostic axillary lymph node dissection--a case-control study

We aimed to compare the accuracy of axillary staging in breast cancer between sentinel node biopsy (SNB) and axillary lymph node dissection (ALND). The prevalence of axillary metastases was studied in 166 breast cancer patients with SNB and pair-matched control patients with ALND. The matching factors included age of the patient and grade, histological type and histological size of the tumour. There were 37% of patients with axillary metastases in the SNB group and 31% in the ALND group. Altogether, 57 pairs were discordant in relation to axillary metastases. In 34 discordant pairs the SNB patient and in 23 the ALND patient had axillary metastases, p=ns. Among the 36 discordant pairs with invasive ductal carcinoma (IDC), axillary metastases were detected as often in the SNB and the ALND patients. In the 21 discordant pairs with other histological types, the SNB patient had axillary metastases in 16 pairs and the ALND patient in 5 pairs, p<0.03. SNB seems to be as accurate a method for axillary staging as ALND. However, SNB generated no upstaging effect in IDC, only in other histological tumour types.