Septins and K63 ubiquitin chains are present in separate bacterial microdomains during autophagy of entrapped Shigella.

During host cell invasion, Shigella escapes to the cytosol and polymerizes actin for cell-to-cell spread. To restrict cell-to-cell spread, host cells employ cell-autonomous immune responses including antibacterial autophagy and septin cage entrapment. How septins interact with the autophagy process to target Shigella for destruction is poorly understood. Here, we employed a correlative light and cryo-soft X-ray tomography (cryo-SXT) pipeline to study Shigella septin cage entrapment in its near-native state. Quantitative cryo-SXT showed that Shigella fragments mitochondria and enabled visualization of X-ray-dense structures (∼30 nm resolution) surrounding Shigella entrapped in septin cages. Using Airyscan confocal microscopy, we observed lysine 63 (K63)-linked ubiquitin chains decorating septin-cage-entrapped Shigella. Remarkably, septins and K63 chains are present in separate bacterial microdomains, indicating they are recruited separately during antibacterial autophagy. Cryo-SXT and live-cell imaging revealed an interaction between septins and LC3B-positive membranes during autophagy of Shigella. Together, these findings demonstrate how septin-caged Shigella are targeted for autophagy and provide fundamental insights into autophagy-cytoskeleton interactions.

DC-SIGN(+) Macrophages Control the Induction of Transplantation Tolerance.

Tissue effector cells of the monocyte lineage can differentiate into different cell types with specific cell function depending on their environment. The phenotype, developmental requirements, and functional mechanisms of immune protective macrophages that mediate the induction of transplantation tolerance remain elusive. Here, we demonstrate that costimulatory blockade favored accumulation of DC-SIGN-expressing macrophages that inhibited CD8(+) T cell immunity and promoted CD4(+)Foxp3(+) Treg cell expansion in numbers. Mechanistically, that simultaneous DC-SIGN engagement by fucosylated ligands and TLR4 signaling was required for production of immunoregulatory IL-10 associated with prolonged allograft survival. Deletion of DC-SIGN-expressing macrophages in vivo, interfering with their CSF1-dependent development, or preventing the DC-SIGN signaling pathway abrogated tolerance. Together, the results provide new insights into the tolerogenic effects of costimulatory blockade and identify DC-SIGN(+) suppressive macrophages as crucial mediators of immunological tolerance with the concomitant therapeutic implications in the clinic.

Bactericidal effect of bacteria isolated from the marine sponges Hymeniacidon perlevis and Halichondria panicea against carbapenem-resistant Acinetobacter baumannii.

In this study, we evaluated the antimicrobial activity of bacteria isolated from the marine sponges Hymeniacidon perlevis and Halichondria panicea against seven Acinetobacter baumannii strains, the majority of which were clinically relevant carbapenem-resistant A. baumannii strains. We observed the inhibitory activity of 18 (out of 114) sponge-isolated bacterial strains against all A. baumanii strains using medium-throughput solid agar overlay assays. These inhibitory strains belonged to the genera Lactococcus, Pseudomonas, and Vagococcus. In addition, this antimicrobial activity was validated through a liquid co-cultivation challenge using an inhibitory strain of each genus and a green fluorescent protein-tagged A. baumanii strain. Fluorescence measurements indicated that the growth of A. baumanii was inhibited by the sponge isolates. In addition, the inability of A. baumanii to grow after spreading the co-cultures on solid medium allowed us to characterize the activity of the sponge isolates as bactericidal. In conclusion, this study demonstrates that marine sponges are a reservoir of bacteria that deserves to be tapped for antibiotic discovery against A. baumanii.

Anti-Anisakis antibodies in colon cancer patients and their relationship with γδ T-cells.

Many pathogens are related to carcinogenesis. Chronic inflammation, as a result of persistent infection, leads to DNA damage, higher expression of oncogenes, decreased apoptosis and immunosuppression, which are some of the reasons for cancer induction. Among parasites, Schistosoma, Opistorchis and Clonorchis are recognised as infectious agents which contribute to cancer. A relationship between Anisakis and cancer was hypothesised because cellular responses to Anisakis products could result in inflammation and DNA damage. Previous research has shown a decrease in CD8+ γδ T-cells and an increase in αß and γδ T-cell apoptosis in colon cancer (CC) samples. Ninety-two CC patients and 60 healthy subjects were recruited. γδ and αß T-cells were analysed, and their apoptosis was evaluated. Anti-Anisakis antibodies were tested in sera from CC patients and controls. Anti-Anisakis IgG, IgM, IgA and IgE antibodies were significantly higher in CC patients. A significant increase in anti-Anisakis IgA levels was observed in patients with angiolymphatic invasion. The number of all γδ T-cells, as well as CD3+ CD4+ αß T-cells, was significantly lower in CC patients. The apoptosis of all T-cells was significantly increased in patients with CC. We observed a significantly higher percentage of anti-Anisakis IgE positive patients having a deficit of CD3+ γδ T-cells. Our results suggest a relationship between Anisakis and CC.

Circular RNA Profile in Atherosclerotic Disease: Regulation during ST-Elevated Myocardial Infarction.

Circular (circ) RNAs are non-coding RNAs with important functions in the nervous system, cardiovascular system, and cancer. Their role in atherosclerosis and myocardial infarction (MI) remains poorly described. We aim to investigate the potential circRNAs in immune cells during atherogenesis and examine the most regulated during MI and the modulation by interleukin (IL)-6 receptor inhibition by tocilizumab. Wild-type (WT) and ApoE-/- mice were fed an atherogenic diet for 10 weeks, and the circRNA profile was analyzed by circRNA microarray. Whole blood from patients with ST-elevated MI (STEMI) and randomized to tocilizumab (n = 21) or placebo (n = 19) was collected at admission, 3-7 days, and at 6 months, in addition to samples from healthy controls (n = 13). Primers for human circRNA were designed, and circRNA levels were measured using RT-qPCR. mRNA regulation of predicted circRNA targets was investigated by RNA sequencing. The expression of 867 circRNAs differed between atherogenic and WT mice. In STEMI patients, circUBAC2 was significantly lower than in healthy controls. CircANKRD42 and circUBAC2 levels were inversely correlated with troponin T, and for circUBAC2, an inverse correlation was also seen with final infarct size at 6 months. The predicted mRNA targets for circUBAC2 and circANKRD42 were investigated and altered levels of transcripts involved in the regulation of inflammatory/immune cells, apoptosis, and mitochondrial function were found. Finally, tocilizumab induced an up-regulation of circANKRD42 and circUBAC2 3-7 days after percutaneous coronary intervention. CircRNA levels were dysregulated in STEMI, potentially influencing the immune system, apoptosis, and mitochondrial function.

Exploring the role of primary fibroblast cells in comparative physiology: a historical and contemporary overview.

With the advent of tissue culture, and eventually the in vitro growth and maintenance of individual cell types, it became possible to ask mechanistic questions about whole organism physiology that are impractical to address within a captive setting or within the whole organism. The earliest studies focused on understanding the wound-healing response while refining cell growth and maintenance protocols from various species. In addition to its extensive use in biomedical research, this approach has been co-opted by comparative physiologists interested in reductionist/mechanistic questions related to how cellular physiology can help explain whole organism function. Here, we provide a historical perspective on the emergence of primary cell culture with an emphasis on fibroblasts followed by an overview of applying this method to ask questions about the role of life-history evolution in shaping organismal physiology at the cellular level, as well as the effect of exogenous factors (i.e., temperature, and oxygen availability) on cellular function. Finally, we propose future uses for primary fibroblasts to address questions in conservation biology and comparative physiology.

Redox regulation, thioredoxins, and glutaredoxins in retrograde signalling and gene transcription.

Integration of reactive oxygen species (ROS)-mediated signal transduction pathways via redox sensors and the thiol-dependent signalling network is of increasing interest in cell biology for their implications in plant growth and productivity. Redox regulation is an important point of control in protein structure, interactions, cellular location, and function, with thioredoxins (TRXs) and glutaredoxins (GRXs) being key players in the maintenance of cellular redox homeostasis. The crosstalk between second messengers, ROS, thiol redox signalling, and redox homeostasis-related genes controls almost every aspect of plant development and stress response. We review the emerging roles of TRXs and GRXs in redox-regulated processes interacting with other cell signalling systems such as organellar retrograde communication and gene expression, especially in plants during their development and under stressful environments. This approach will cast light on the specific role of these proteins as redox signalling components, and their importance in different developmental processes during abiotic stress.

Evaluation of the novel therapeutic anti-CCR7 antibody CAP-100 as an add-on therapy in chronic lymphocytic leukemia patients receiving venetoclax.

The Bruton's tyrosine kinase inhibitor ibrutinib and the B-cell lymphoma 2 anti-apoptotic protein inhibitor venetoclax provide high response rates in chronic lymphocytic leukemia (CLL). However, there is a growing number of patients that relapse after treatment or show refractory disease, thus new targets and agents are still needed. We have previously reported the chemokine receptor CCR7 as a relevant deregulated target in CLL and have developed CAP-100, a novel therapeutic anti-CCR7 antibody that is under evaluation for relapse/refractory CLL (NCT04704323). While CCR7 expression has been shown to be down-modulated in CLL patients treated with ibrutinib, whether venetoclax acts in a similar manner remains unaddressed. Here, we aimed to document the impact of venetoclax on CCR7 expression in CLL cells, as well as on the pre-clinical activity of CAP-100. To this end, we addressed CCR7 expression by flow cytometry and the antibody efficacy by means of in vitro chemotactic and antibody-dependent cell-mediated cytotoxicity (ADCC) assays. Our data indicate that venetoclax treatment did not significantly modify CCR7 expression pattern nor CAP-100 mechanisms of action. Together, these findings support CAP-100 as an adjuvant therapy to venetoclax that may introduce additional modes of action in CLL therapy.

Inflammaging in domestic dogs: basal level concentrations of IL-6, IL-1ß, and TNF-α in serum of healthy dogs of different body sizes and ages.

Inflammaging, a "hallmark of aging," refers to a chronic, progressive increase in the proinflammatory status of mammals as they age, and this phenotype has been associated with many age-related diseases, including cardiovascular disease, arthritis and cancer. Though, inflammaging research is common in humans, there is a lack of data for this process for the domestic dog. Here, serum concentrations of IL-6, IL-1ß and TNF-α in healthy dogs of different body sizes and ages were measured to determine whether inflammaging may play a mechanistic role in aging rates in dogs, similar to those found in humans. Using a four-way ANOVA, a significant decrease in IL-6 concentrations in young dogs with the rest of the age categories showing increased IL-6 concentrations was found, similar to humans. However, only young dogs have decreased IL-6 concentrations, with adult dogs having similar IL-6 concentrations to senior and geriatric dogs, implying differences in aging rates between humans and dogs. And, there was a marginally significant interaction between sex*spayed or neutered status and IL-1ß concentrations with intact females having the lowest IL-1ß concentrations compared with intact males, and spayed and neutered dogs. The presence of estrogen in intact females may, overall, decrease inflammatory pathways. This implies that age at spaying or neutering may be an important aspect to consider for inflammaging pathways in dogs. Furthermore, sterilized dogs often die of immune-related diseases, which could be linked to the increases in IL-1ß in sterilized dogs found in this study.

Al-Pt intermetallic compounds: HAXPES study.

Intermetallic compounds in the Al-Pt system were systematically studied via hard X-ray photoelectron spectroscopy, focusing on the positions of Pt 4f and Al 2s core levels and valence band features. On one hand, with increasing Al content, the Pt 4f core levels shift towards higher binding energies (BE), revealing the influence of the atomic interactions (chemical bonding) on the electronic state of Pt. On the other hand, the charge transfer from Al to Pt increases with increasing Al content in Al-Pt compounds. These two facts cannot be combined using the standard "chemical shift" approach. Computational analysis reveals that higher negative effective charges of Pt atoms are accompanied by reduced occupancy of Pt 5d orbitals, leading to the limited availability of these electrons for the screening of the 4f core hole and this in turn explains the experimentally observed shift of 4f core levels to higher BE.