The atypical receptor CCRL2 (C-C Chemokine Receptor-Like 2) does not act as a decoy receptor in endothelial cells

C-C chemokine receptor-like 2 (CCRL2) is a non-signaling seven-transmembrane domain (7-TMD) receptor related to the atypical chemokine receptor (ACKR) family. ACKRs bind chemokines but do not activate G protein-dependent signaling or cell functions. ACKRs were shown to regulate immune functions in vivo by their ability to scavenge chemokines from the local environment. This study was performed to investigate whether CCRL2 shares two of the main characteristics of ACKRs, namely the ability to internalize and scavenge the ligands. Cell membrane analysis of CCRL2-transfected cells revealed a weak, constitutive, ligand-independent internalization, and recycling of CCRL2, with a kinetics that was slower than those observed with ACKR3, a prototypic ACKR, or other chemotactic signaling receptors [i.e., chemokine-like receptor 1 and C-X-C motif chemokine receptor 2]. Intracellularly, CCRL2 colocalized with early endosome antigen 1-positive and Rab5-positive vesicles and with recycling compartments mainly characterized by Rab11-positive vesicles. CCRL2-transfected cells and activated mouse blood endothelial cells, that endogenously express CCRL2, were used to investigate the scavenging ability of CCRL2. These experiments confirmed the ability of CCRL2 to bind chemerin, the only recognized ligand, but excluded the ability of CCRL2 to perform scavenging. Collectively, these results identify unique functional properties for this member of the non-signaling 7-TMD receptor family

Migration of dendritic cells across blood and lymphatic endothelial barriers.

7openopenDel Prete A; Locati M; Otero K; Riboldi E; Mantovani A; Vecchi A; Sozzani S.DEL PRETE, Annalisa; Locati, M; Otero, K; Riboldi, E; Mantovani, A; Vecchi, A; Sozzani, Silvan

In vitro activity of ceftazidime/avibactam alone and in combination with fosfomycin and carbapenems against KPC-producing Klebsiella pneumoniae

KPC-producing Klebsiella pneumonia (KPC-Kp) represents a major therapeutic challenge in critically ill patients. Ceftazidime-avibactam (CAZ-AVI) is a new effective drug against KPC-Kp but, due to emerging resistant strains during monotherapy, the association with a second antibiotic has been advocated. Therefore, intravenous fosfomycin may be a possible choice for combination therapy. The aim of this study was to evaluate the in vitro susceptibility of CAZ-AVI alone and in combination with fosfomycin and carbapenems against KPC-Kp clinical isolates by E-test method. The combination of CAZ-AVI with carbapenems showed synergistic activity, whereas with fosfomycin showed addictive activity, suggesting that fosfomycin may be a carbapenem-sparing strategy in antimicrobial stewardship programs

Inhibitory receptors of plasmacytoid dendritic cells as possible targets for checkpoint blockade in cancer

Plasmacytoid dendritic cells (pDCs) are the major producers of type I interferons (IFNs), which are essential to mount antiviral and antitumoral immune responses. To avoid exaggerated levels of type I IFNs, which pave the way to immune dysregulation and autoimmunity, pDC activation is strictly regulated by a variety of inhibitory receptors (IRs). In tumors, pDCs display an exhausted phenotype and correlate with an unfavorable prognosis, which largely depends on the accumulation of immunosuppressive cytokines and oncometabolites. This review explores the hypothesis that tumor microenvironment may reduce the release of type I IFNs also by a more pDC-specific mechanism, namely the engagement of IRs. Literature shows that many cancer types express de novo, or overexpress, IR ligands (such as BST2, PCNA, CAECAM-1 and modified surface carbohydrates) which often represent a strong predictor of poor outcome and metastasis. In line with this, tumor cells expressing ligands engaging IRs such as BDCA-2, ILT7, TIM3 and CD44 block pDC activation, while this blocking is prevented when IR engagement or signaling is inhibited. Based on this evidence, we propose that the regulation of IFN secretion by IRs may be regarded as an "innate checkpoint", reminiscent of the function of "classical" adaptive immune checkpoints, like PD1 expressed in CD8+ T cells, which restrain autoimmunity and immunopathology but favor chronic infections and tumors. However, we also point out that further work is needed to fully unravel the biology of tumor-associated pDCs, the neat contribution of pDC exhaustion in tumor growth following the engagement of IRs, especially those expressed also by other leukocytes, and their therapeutic potential as targets of combined immune checkpoint blockade in cancer immunotherapy

Parentification, distress, and relationship with parents as factors shaping the relationship between adult siblings and their brother/sister with disabilities

According to parentification theory, when the siblings of a brother/sister with disabilities assume parent-like duties, this role reversal is known as sibling-focused parentification. It has a significant impact on these siblings’ distress and the quality of their family relationships; 605 Italian adult siblings (19–26 years) of people with disabilities completed the online survey. Measures of siblings’ parentification, distress, quality of family relationships, social support, and perceived benefits of parentification were used. The hypothesized model aims to test, on the target sample, the distress and the quality of the relationship with parents as mediators on the interplay between the siblings’ parentification and their sibling relationship. Additionally, social support and perceived benefits of parentification as protective factors were considered. Results showed that the distress and the low quality of the relationship with parents negatively affected the interplay between the siblings’ parentification and the relationship with their own brother/sister with disabilities. Social support and the perceived benefits of parentification decreased the siblings’ distress levels; the perceived benefits of parentification served as a protective factor for the quality of the relationship with parents. Current findings extend the knowledge regarding the risk and protective factors of the siblings’ mental health when disability occurs in the family. Additionally, they inform family-based intervention programs, which should involve the whole family system for reducing distress and improving the wellbeing of siblings without disabilities

Inhibition of Class I Histone Deacetylase Activity Blocks the Induction of TNFAIP3 Both Directly and Indirectly via the Suppression of Endogenous TNF-α

Histone deacetylase inhibitors (HDIs) are promising drugs for the treatment of inflammatory diseases. However, their therapeutical exploitation is slowed down by severe adverse manifestations that can hardly be foreseen, mainly due to incomplete knowledge of how HDIs impact the delicate balance of inflammatory mediators. In this work, we characterized the effects of the HDI trichostatin A (TSA) on the expression of TNFAIP3, which is a crucial inhibitor of the classical NF-kB pathway and an LPS-induced negative feedback regulator. The accumulation of TNFAIP3 mRNA after LPS stimulation showed biphasic behavior, with one wave within the first hour of stimulation and a second wave several hours later, which were both reduced by TSA. By using inhibition and knockdown approaches, we identified two temporally and mechanistically distinct modes of action. The first wave of TNAIP3 accumulation was directly blunted by the histone deacetylase (HDAC) blockade. By contrast, the second wave was decreased mainly because of the lack of endogenous TNF-α induction, which, in turn, depended on the intact HDAC activity. In both cases, class I HDACs appeared to play a nonredundant role, with HDAC3 required, but not sufficient, for TNF-α and TNFAIP3 induction. In addition to TNFAIP3, TNF-α is known to induce many response genes that orchestrate the inflammatory cascade. Thus, suppression of TNF-α may represent a general mechanism through which HDIs regulate a selected set of target genes