E. coli promotes human Vγ9Vδ2 T cell transition from cytokine-producing bactericidal effectors to professional phagocytic killers in a TCR-dependent manner

γδT cells provide immune-surveillance and host defense against infection and cancer. Surprisingly, functional details of γδT cell antimicrobial immunity to infection remain largely unexplored. Limited data suggests that γδT cells can phagocytose particles and act as professional antigen-presenting cells (pAPC). These potential functions, however, remain controversial. To better understand γδT cell-bacterial interactions, an ex vivo co-culture model of human peripheral blood mononuclear cell (PBMC) responses to Escherichia coli was employed. Vγ9Vδ2 cells underwent rapid T cell receptor (TCR)-dependent proliferation and functional transition from cytotoxic, inflammatory cytokine immunity, to cell expansion with diminished cytokine but increased costimulatory molecule expression, and capacity for professional phagocytosis. Phagocytosis was augmented by IgG opsonization, and inhibited by TCR-blockade, suggesting a licensing interaction involving the TCR and FcγR. Vγ9Vδ2 cells displayed potent cytotoxicity through TCR-dependent and independent mechanisms. We conclude that γδT cells transition from early inflammatory cytotoxic killers to myeloid-like APC in response to infectious stimuli

Exome-wide association analysis reveals novel coding sequence variants associated with lipid traits in Chinese

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Tetanus toxin Hc fragment induces the formation of ceramide platforms and protects neuronal cells against oxidative stress

Tetanus toxin (TeTx) is the protein, synthesized by the anaerobic bacteria Clostridium tetani, which causes tetanus disease. TeTx gains entry into target cells by means of its interaction with lipid rafts, which are membrane domains enriched in sphingomyelin and cholesterol. However, the exact mechanism of host membrane binding remains to be fully established. In the present study we used the recombinant carboxyl terminal fragment from TeTx (Hc-TeTx), the domain responsible for target neuron binding, showing that Hc-TeTx induces a moderate but rapid and sustained increase in the ceramide/sphingomyelin ratio in primary cultures of cerebellar granule neurons and in NGF-differentiated PC12 cells, as well as induces the formation of ceramide platforms in the plasma membrane. The mentioned increase is due to the promotion of neutral sphingomyelinase activity and not to the de novo synthesis, since GW4869, a specific neutral sphingomyelinase inhibitor, prevents neutral sphingomyelinase activity increase and formation of ceramide platforms. Moreover, neutral sphingomyelinase inhibition with GW4869 prevents Hc-TeTx-triggered signaling (Akt phosphorylation), as well as the protective effect of Hc-TeTx on PC12 cells subjected to oxidative stress, while siRNA directed against nSM2 prevents protection by Hc-TeTx of NSC-34 cells against oxidative insult. Finally, neutral sphingomyelinase activity seems not to be related with the internalization of Hc-TeTx into PC12 cells. Thus, the presented data shed light on the mechanisms triggered by TeTx after membrane binding, which could be related with the events leading to the neuroprotective action exerted by the Hc-TeTx fragment

An approximation solution for the 2-median problem on two-dimensional meshes

We study the p-median problem which is one of the classical problems in location theory. For p = 2 and on a two-dimensional mesh, we give an O(m 2 + q log q)-time approximation algorithm for solving the problem with worst-case ratio 1.5+δ on the communication cost, where m is the number of rows of the mesh containing demand points, n the number of columns containing demand points, m ≥ n, q the number of demand points, and 6 is some positive constant which can be as small as needed. © 2005 IEEE.link_to_subscribed_fulltex

Pediatric rheumatology education: the virtual frontier a review

\ua9 The Author(s) 2024. Background: Many children with rheumatic and musculoskeletal diseases are unrecognized. Identifying these children requires health care provider awareness, knowledge, and skills to recognize disease features and how (and when) to refer to specialist care. The aim of this paper is to highlight the need for better access to health care, review the essential role that education and virtual care play to address unmet need in low resource areas and especially to expand workforce capacity. Using collaborative partnerships, virtual platforms, and innovative assessment methods, musculoskeletal care and education can be delivered to reach a greater audience than ever before. Increased awareness through multiple initiatives and readily available resources are imperative to improve global rheumatology care. Conclusion: The needs of children with rheumatic diseases and musculoskeletal conditions are vastly underserved around the world resulting in preventable morbidity and mortality. Expanded implementation of virtual education and e-health care platforms provides an opportunity to increase access to care for children globally

Image-based analysis of phagocytosis: measuring engulfment and internalization

The process of phagocytosis is crucial for fighting infection in innate immunity, for maintaining homeostasis through clearing cell debris, and for tissue remodeling in development. Here we describe two semi- automated image-based assays for the quantitative characterization of the early stages of phagocytosis and pathogen entry. A feature of these assays is the ability to detect and assess molecules or agents that subtly affect the stages both before and after cup closure or internalization