Chemokines form nanoparticles with DNA and can superinduce TLR-driven immune inflammation

Chemokines control the migratory patterns and positioning of immune cells to organize immune responses to pathogens. However, many chemokines have been associated with systemic autoimmune diseases that have chronic IFN signatures. We report that a series of chemokines, including CXCL4, CXCL10, CXCL12, and CCL5, can superinduce type I IFN (IFN-I) by TLR9-activated plasmacytoid DCs (pDCs), independently of their respective known chemokine receptors. Mechanistically, we show that chemokines such as CXCL4 mediate transcriptional and epigenetic changes in pDCs, mostly targeted to the IFN-I pathways. We describe that chemokines physically interact with DNA to form nanoparticles that promote clathrin-mediated cellular uptake and delivery of DNA in the early endosomes of pDCs. Using two separate mouse models of skin inflammation, we observed the presence of CXCL4 associated with DNA in vivo. These data reveal a noncanonical role for chemokines to serve as nucleic acid delivery vectors to modulate TLR signaling, with implications for the chronic presence of IFN-I by pDCs in autoimmune diseases.

Teaching and Assessment of Medical Students During Complex Multifactorial Team-Based Tasks: The "Virtual on Call" Case Study

Abstract

Although considerable efforts have been made to incorporate simulation-based learning (SBL) in undergraduate medical education, to date, most of the medical school curricula still focus on pure knowledge or individual assessment of objective structured clinical examination skills (OSCE). To this end, we designed a case study named "iG4 (integrated generation 4) virtual on-call (iVOC)". We aimed to simulate an on-call shift in a high-fidelity virtual hospital setting in order to assess delegates' team-based performance on tasks related to patient handovers (prioritisation, team allocation).

Methods

A total of 41 clinical year medical students were split into 3 cohorts, each of which included 3 groups of 4 or 5 people. The groups consisted of a structured mix of educational and cultural backgrounds of students to achieve homogeneity. Each performing group received the handover for 5 patients in the virtual hospital and had to identify and deal with the acutely unwell ones within 15 minutes. We used TEAMTM tool to assess team-based performances.

Results

The mean handover performance was 5.44/10 ± 2.24 which was the lowest across any performance marker. The overall global performance across any team was 6.64/10 ± 2.11. The first rotating team's global performance for each cycle was 6.44/10 ± 2.01, for the second 7.89/10 ± 2.09 and for the third 6.78/10 ± 1.64 (p = 0.099 between groups).

Conclusion

This is one of the first reported, high-fidelity, globally reproducible SBL settings to assess the capacity of students to work as part of a multinational team, highlighting several aspects that need to be addressed during undergraduate studies. Medical schools should consider similar efforts with the aim to incorporate assessment frameworks for individual performances of students as part of a team, which can be a stepping-stone for enhancing safety in clinical practice.

Noncytotoxic Inhibition of the Immunoproteasome Regulates Human Immune Cells In Vitro and Suppresses Cutaneous Inflammation in the Mouse

Inhibitors of the immunoproteasome (i-20S) have shown promise in mouse models of autoimmune diseases and allograft rejection. In this study, we used a novel inhibitor of the immunoproteasome, PKS3053, that is reversible, noncovalent, tight-binding, and highly selective for the β5i subunit of the i-20S to evaluate the role that i-20S plays in regulating immune responses in vitro and in vivo. In contrast to irreversible, less-selective inhibitors, PKS3053 did not kill any of the primary human cell types tested, including plasmacytoid dendritic cells, conventional dendritic cells, macrophages, and T cells, all of which expressed genes encoding both the constitutive proteasome (c-20S) and i-20S. PKS3053 reduced TLR-dependent activation of plasmacytoid dendritic cells, decreasing their maturation and IFN-α response and reducing their ability to activate allogenic T cells. In addition, PKS3053 reduced T cell proliferation directly and inhibited TLR-mediated activation of conventional dendritic cells and macrophages. In a mouse model of skin injury that shares some features of cutaneous lupus erythematosus, blocking i-20S decreased inflammation, cellular infiltration, and tissue damage. We conclude that the immunoproteasome is involved in the activation of innate and adaptive immune cells, that their activation can be suppressed with an i-20S inhibitor without killing them, and that selective inhibition of β5i holds promise as a potential therapy for inflammatory skin diseases such as psoriasis, cutaneous lupus erythematosus, and systemic sclerosis.

A Novel Multi-faceted Course Blueprint to Support Outcome-based Holistic Surgical Education: The Integrated Generation 4 Model (iG4)

BACKGROUND/AIM

We present a novel multi-faceted, internationally adaptable course curriculum blueprint, which provides holistic surgical education at the undergraduate level.

MATERIALS AND METHODS

The Integrated Generation 4 (iG4) course (Essential Skills in the Management of Surgical Cases - ESMSC Marathon course) curriculum consists of four essential learning components: core skills-based learning, case-based discussions, basic science workshops and soft-skills. These are all clustered in a specialty-led network architecture. Every cluster consists of modules from the four learning cores, while network nodes are modules that are mutually shared by more than one clusters.

RESULTS

We produced a standardized blueprint of 50 modules based on the 4 learning cores, covering 9 surgical specialties. This resulted in a curriculum map where every module is described using 3 parameters: χ axis (skills component), y axis (knowledge component), z axis (specialty component).

CONCLUSION

iG4 proof of concept sets the ground for a novel, reproducible and standardised effort to produce a portfolio of undergraduate surgical skills serving the vision of holistic surgical education.

Clinico-pathological correlations in 127 patients in 11 large pedigrees, segregating one of three heterozygous mutations in the COL4A3/ COL4A4 genes associated with familial haematuria and significant late progression to proteinuria and chronic kidney disease from focal segmental glomerulosclerosis

BACKGROUND

Heterozygous mutations in the COL4A3/ COL4A4 genes are currently thought to be responsible for familial benign microscopic haematuria and maintenance of normal long-term kidney function.

METHODS

We report on 11 large Cypriot pedigrees with three such mutations. A total of 236 at-risk family members were genetically studied, and 127 (53.8%) carried a heterozygous mutation. Clinico-pathological correlations were available in all of these patients. Renal biopsies in 21 of these patients all showed various stages of focal, segmental glomerulosclerosis (FSGS). Thirteen of these biopsies were also studied with EM and showed thinning of the glomerular basement membrane.

RESULTS

Mutation G1334E (COL4A3) was found in six pedigrees, mutation G871C (COL4A3) in four and mutation 3854delG (COL4A4) in one pedigree. Clinical and laboratory correlations in all 127 mutation carriers (MC) showed that microscopic haematuria was the only urinary finding in patients under age 30. The prevalence of 'haematuria alone' fell to 66% between 31 and 50 years, to 30% between 51 and 70 and to 23% over age 71. Proteinuria with CRF developed on top of haematuria in 8% of all MC between 31 and 50 years, to 25% between 51 and 70 years and to 50% over 71 years. Altogether 18 of these 127 MC (14%) developed ESRD at a mean age of 60 years. Two members with different mutations married, and two of their children inherited both mutations and developed adolescent, autosomal recessive Alport syndrome (ATS), confirming that these mutations are pathogenic.

CONCLUSIONS

Our data confirm for the first time a definite association of heterozygous COL4A3/COL4A4 mutations with familial microscopic haematuria, thin basement membrane nephropathy and the late development of familial proteinuria, CRF, and ESRD, due to FSGS, indicating that the term 'benign familial haematuria' is a misnomer, at least in this cohort. A strong hypothesis for a causal relationship between these mutations and FSGS is also made. Benign familial haematuria may not be so benign as commonly thought.

Ability of dairy strains of lactic acid bacteria to bind aflatoxin M1 in a food model

Aflatoxin M1 (AFM1) is a highly toxic compound found in milk. Its occurrence poses a threat to the health of consumers, especially young children, and leads to economic losses due to contaminated milk. The problem is global but more severe in developing countries. Consequently, there is a great demand for novel strategies to prevent the contamination and adverse effects of AFM1. To develop a safe and practical decontamination method, a preliminary study was carried out with specific lactic acid bacteria strains that were tested for their ability to remove AFM1 from liquid media. All strains, whether viable or heat-killed, could reduce the AFM1 content of a liquid medium. Two most effective strains were also tested using contaminated skim and full cream milk. The results indicate that specific lactic acid bacteria used in dairy products can offer novel means of decontaminating aflatoxin M1 from milk.