Reconstruction of LPS Transfer Cascade Reveals Structural Determinants within LBP, CD14, and TLR4-MD2 for Efficient LPS Recognition and Transfer.

Lipopolysaccharide (LPS), the major component of the outer membrane of Gram-negative bacteria, binds Toll-like receptor 4 (TLR4)-MD2 complex and activates innate immune responses. LPS transfer to TLR4-MD2 is catalyzed by both LPS binding protein (LBP) and CD14. To define the sequential molecular interactions underlying this transfer, we reconstituted in vitro the entire LPS transfer process from LPS micelles to TLR4-MD2. Using electron microscopy and single-molecule approaches, we characterized the dynamic intermediate complexes for LPS transfer: LBP-LPS micelles, CD14-LBP-LPS micelle, and CD14-LPS-TLR4-MD2 complex. A single LBP molecule bound longitudinally to LPS micelles catalyzed multi-rounds of LPS transfer to CD14s that rapidly dissociated from LPB-LPS complex upon LPS transfer via electrostatic interactions. Subsequently, the single LPS molecule bound to CD14 was transferred to TLR4-MD2 in a TLR4-dependent manner. The definition of the structural determinants of the LPS transfer cascade to TLR4 may enable the development of targeted therapeutics for intervention in LPS-induced sepsis.

By Capturing Inflammatory Lipids Released from Dying Cells, the Receptor CD14 Induces Inflammasome-Dependent Phagocyte Hyperactivation.

A heterogeneous mixture of lipids called oxPAPC, derived from dying cells, can hyperactivate dendritic cells (DCs) but not macrophages. Hyperactive DCs are defined by their ability to release interleukin-1 (IL-1) while maintaining cell viability, endowing these cells with potent aptitude to stimulate adaptive immunity. Herein, we found that the bacterial lipopolysaccharide receptor CD14 captured extracellular oxPAPC and delivered these lipids into the cell to promote inflammasome-dependent DC hyperactivation. Notably, we identified two specific components within the oxPAPC mixture that hyperactivated macrophages, allowing these cells to release IL-1 for several days, by a CD14-dependent process. In murine models of sepsis, conditions that promoted cell hyperactivation resulted in inflammation but not lethality. Thus, multiple phagocytes are capable of hyperactivation in response to oxPAPC, with CD14 acting as the earliest regulator in this process, serving to capture and transport these lipids to promote inflammatory cell fate decisions.

Microbial stimulation fully differentiates monocytes to DC-SIGN/CD209(+) dendritic cells for immune T cell areas.

Dendritic cells (DCs), critical antigen-presenting cells for immune control, normally derive from bone marrow precursors distinct from monocytes. It is not yet established if the large reservoir of monocytes can develop into cells with critical features of DCs in vivo. We now show that fully differentiated monocyte-derived DCs (Mo-DCs) develop in mice and DC-SIGN/CD209a marks the cells. Mo-DCs are recruited from blood monocytes into lymph nodes by lipopolysaccharide and live or dead gram-negative bacteria. Mobilization requires TLR4 and its CD14 coreceptor and Trif. When tested for antigen-presenting function, Mo-DCs are as active as classical DCs, including cross-presentation of proteins and live gram-negative bacteria on MHC I in vivo. Fully differentiated Mo-DCs acquire DC morphology and localize to T cell areas via L-selectin and CCR7. Thus the blood monocyte reservoir becomes the dominant presenting cell in response to select microbes, yielding DC-SIGN(+) cells with critical functions of DCs.

Interleukin-12 and -23 Control Plasticity of CD127(+) Group 1 and Group 3 Innate Lymphoid Cells in the Intestinal Lamina Propria.

Human group 1 ILCs consist of at least three phenotypically distinct subsets, including NK cells, CD127(+) ILC1, and intraepithelial CD103(+) ILC1. In inflamed intestinal tissues from Crohn's disease patients, numbers of CD127(+) ILC1 increased at the cost of ILC3. Here we found that differentiation of ILC3 to CD127(+) ILC1 is reversible in vitro and in vivo. CD127(+) ILC1 differentiated to ILC3 in the presence of interleukin-2 (IL-2), IL-23, and IL-1ß dependent on the transcription factor RORγt, and this process was enhanced in the presence of retinoic acid. Furthermore, we observed in resection specimen from Crohn's disease patients a higher proportion of CD14(+) dendritic cells (DC), which in vitro promoted polarization from ILC3 to CD127(+) ILC1. In contrast, CD14(-) DCs promoted differentiation from CD127(+) ILC1 toward ILC3. These observations suggest that environmental cues determine the composition, function, and phenotype of CD127(+) ILC1 and ILC3 in the gut.

Lipopolysaccharide Induces Alveolar Macrophage Necrosis via CD14 and the P2X7 Receptor Leading to Interleukin-1α Release.

Acute lung injury (ALI) remains a serious health issue with little improvement in our understanding of the pathophysiology and therapeutic approaches. We investigated the mechanism that lipopolysaccharide (LPS) induces early neutrophil recruitment to lungs and increases pulmonary vascular permeability during ALI. Intratracheal LPS induced release of pro-interleukin-1α (IL-1α) from necrotic alveolar macrophages (AM), which activated endothelial cells (EC) to induce vascular leakage via loss of vascular endothelial (VE)-cadherin. LPS triggered the AM purinergic receptor P2X7(R) to induce Ca(2+) influx and ATP depletion, which led to necrosis. P2X7R deficiency significantly reduced necrotic death of AM and release of pro-IL-1α into the lung. CD14 was required for LPS binding to P2X7R, as CD14 neutralization significantly diminished LPS induced necrotic death of AM and pro-IL-1α release. These results demonstrate a key role for pro-IL-1α from necrotic alveolar macrophages in LPS-mediated ALI, as a critical initiator of increased vascular permeability and early neutrophil infiltration.

Classical complement and inflammasome activation converge in CD14highCD16- monocytes in HIV associated TB-immune reconstitution inflammatory syndrome.

Inflammasome-derived cytokines, IL-1ß and IL-18, and complement cascade have been independently implicated in the pathogenesis of tuberculosis (TB)-immune reconstitution inflammatory syndrome (TB-IRIS), a complication affecting HIV+ individuals starting antiretroviral therapy (ART). Although sublytic deposition of the membrane attack complex (MAC) has been shown to promote NLRP3 inflammasome activation, it is unknown whether these pathways may cooperatively contribute to TB-IRIS. To evaluate the activation of inflammasome, peripheral blood mononuclear cells (PBMCs) from HIV-TB co-infected patients prior to ART and at the IRIS or equivalent timepoint were incubated with a probe used to assess active caspase-1/4/5 followed by screening of ASC (apoptosis-associated speck-like protein containing a CARD domain) specks as a readout of inflammasome activation by imaging flow cytometry. We found higher numbers of monocytes showing spontaneous caspase-1/4/5+ASC-speck formation in TB-IRIS compared to TB non-IRIS patients. Moreover, numbers of caspase-1/4/5+ASC-speck+ monocytes positively correlated with IL-1ß/IL-18 plasma levels. Besides increased systemic levels of C1q and C5a, TB-IRIS patients also showed elevated C1q and C3 deposition on monocyte cell surface, suggesting aberrant classical complement activation. A clustering tSNE analysis revealed TB-IRIS patients are enriched in a CD14highCD16- monocyte population that undergoes MAC deposition and caspase-1/4/5 activation compared to TB non-IRIS patients, suggesting complement-associated inflammasome activation during IRIS events. Accordingly, PBMCs from patients were more sensitive to ex-vivo complement-mediated IL-1ß secretion than healthy control cells in a NLRP3-dependent manner. Therefore, our data suggest complement-associated inflammasome activation may fuel the dysregulated TB-IRIS systemic inflammatory cascade and targeting this pathway may represent a novel therapeutic approach for IRIS or related inflammatory syndromes.

The CD36 and SR-A/CD204 scavenger receptors fine-tune Staphylococcus aureus-stimulated cytokine production in mouse macrophages.

The occurring in SR-A/CD204- or CD36-deficient mice increased susceptibility to infections with Staphylococcus aureus (Sa) had traditionally been ascribed to the impairment of macrophage-mediated phagocytosis, which is, however, inconsistent with low effectiveness of unopsonized Sa killing within macrophages and redundant roles of both receptors in this process. We have found that Sa-stimulated cytokine production in mouse macrophages seems to be exclusively mediated by TLR2, mainly from within endosomes in response to Sa-derived lipoteichoic acid. By driving endocytic trafficking of TLR2 and its ligands through the clathrin-dependent pathway, CD36 and SR-A sensitize macrophages to activation by Sa as well as regulate the type and amount of cytokines produced. Additionally, upon direct Sa binding, both receptors autonomously generate anti-inflammatory signaling. Consequently, the delayed induction of acute inflammation in knockout mice may allow for the initial, uncontrolled multiplication of bacteria, stimulating excessive, septic shock-inducing production of inflammatory cytokines in later stages of infection.

Clinical and prognostic significance of CD14 (+) HLA-DR (-/low) myeloid-derived suppressor cells in patients with hepatocellular carcinoma received transarterial radioembolization with Yttrium-90.

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. For unresectable HCC, transarterial radioembolization (TARE) with Yttrium-90 is a widely used treatment. The aim of this study was to investigate whether monocytic myeloid-derived suppressor cells (M-MDSC) and CD39+ T cells can be non-invasive predictive biomarkers of radiological response and prognosis in patients with HCC treated with TARE. This study was conducted on 39 patients with HCC who were treated with TARE between August 2018 and December 2019 and the control group consisted of 23 healthy volunteers. CD4+, CD8+, CD39+ T cells, Natural killer (NK) cells, myeloid cells (MC) and M-MDSC parameters are examined in the course of TARE treatment with student t test and Kaplan-Meier method. There were statistically significant differences in M-MDSC, CD39+ T cells and MC values between healthy controls and HCC patients. A statistically significant difference was found in M-MDSC and CD4+ T cells values in the HCC patient group who responded to the treatment compared to those who did not. Survival analysis found that patients with lower frequencies (under 3.81%) of M-MDSC showed more prominent differences of overall survival (OS) compared to patients with all high groups. We found that M-MDSC in the peripheral blood might be a useful non-invasive biomarker to predict OS. We have shown for the first time that M-MDSC is correlated with treatment response in HCC patients treated with TARE. Additionally, we have found that the percentage of CD39+ T cells is high in HCC patients and these cells are positively correlated with M-MDSC.

High CD14+ peripheral monocytes expression of ALX/FPR2 and BLT1 in low disease activity and remission status in rheumatoid arthritis: a piltot study.

OBJECTIVES: Specialised pro-resolving mediator (SPM) can dampen the acute inflammation through ERV1, ALX/FPR2 and BLT1 cell receptors and it is conceivable that their expression is dysregulated during chronic inflammation. The aim of this study was to evaluate the expression of ERV1, ALX/FPR2 and BLT1 on peripheral blood (PB) cells from rheumatoid arthritis (RA) patients. METHODS: At baseline, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), clinimetric indexes (28-joint disease activity score (DAS28) and clinical disease activity index (CDAI)), and PB samples were collected from 33 RA patients. Based on DAS28, patients were divided into high-moderate (H-Mo/RA, DAS28≥3.2) and low-remission (L-Rem/RA, DAS28<3.2) disease activity group. Cell membrane expression of ERV1, ALX/FPR2 and BLT1 on CD3pos, CD19pos, CD14pos cells and granulocytes was assessed by multi-parametric flow-cytometry analysis. Nine healthy controls (HC) were also studied. RESULTS: Sixteen H-Mo/RA and 17 L-Rem/RA patients were identified. The percentage of BLT1posCD14pos cells was significantly higher in L-Rem/RA (47.17%) than in H-Mo/RA (14.27%) group (p=0.005). Likewise, the percentage ALX/FPR2pos CD14pos cells was significantly higher in L-Rem/RA (33.02%) than in H-Mo/RA (8.77%; p=0.04) patients. An inverse correlation between BLT1posCD14pos cell percentage and DAS28 (r=-0.42; p=0.01), CDAI (r=-0.51; p=0.003), ESR (r=-0.39; p=0.025) and CRP (r=-0.40; p=0.02), ALX/FPR2posCD14pos cell percentage and CRP (r=-0.39; p=0.02) were found, while SPM-receptors mean fluorescence intensity (MFI) was not different between HC and L-Rem/RA patients. CONCLUSIONS: ALX/FPR2 and BLT1 receptors expression mirrors RA disease activity arising as potential biomarkers of inflammatory regulation.

Inhibition of Borrelia Burgdorferi-Induced TLR2-NFκB Canonical Signaling by Gallic Acid through Targeting the CD14+ Adaptor Protein and p65 Molecule.

The cases of Lyme disease caused by Borrelia burgdorferi infection have been increasing throughout Northern America and Europe. This pathogen, if not treated in a timely manner with antibiotics, can cause persisting and debilitating health outcomes. In the search for novel agents against B. burgdorferi, we investigated a phenolic compound-gallic acid-for its anti-Borrelia and anti-inflammatory effects. Our results showed its biocidal effect starting from 100 µg/mL against active spirochetes, persisters/round-shaped bodies, and biofilm like aggregates of B. burgdorferi sensu stricto. Activation of macrophages by live B. burgdorferi also resulted in a robust NFκB-dependent proinflammatory responses seen in increased production of cytokines. Using human CD14+ macrophages in vitro, we showed that CD14+ adaptor and phosphorylated p65 molecule are impeded at nonbiocidal and noncytotoxic concentrations of gallic acid, resulting in the inhibition of both expression and secretion of cytokines IL1ß, IL6, and TNFα. Our findings demonstrate efficacy of gallic acid against B. burgdorferi and provide potential mechanistic insight into its TLR2/CD14+-NFκB mediated mode of action. Further studies on the potential of gallic acid as a safe and effective compound against Borrelia-caused infection are warranted.

Glucocorticoid treatment in patients with newly diagnosed immune thrombocytopenia switches CD14++ CD16+ intermediate monocytes from a pro-inflammatory to an anti-inflammatory phenotype.

Immune thrombocytopenia (ITP) is thought to result from an aberrant adaptive autoimmune response, involving autoantibodies, B and T lymphocytes, directed at platelets and megakaryocytes. Previous reports have demonstrated skewed CD4+ T-helper subset distribution and enhanced production of pro-inflammatory cytokines such as interleukin 17A and interferon gamma. The role of monocytes (MCs) in ITP is less widely described, but innate immune cells have a role in shaping CD4+ T-cell phenotypes. Glucocorticoids (GCs) are commonly used for first-line ITP treatment and modulate a broad range of immune cells including T cells and MCs. Using multiparameter flow cytometry analysis, we demonstrate the expansion of intermediate MCs (CD14++ CD16+ ) in untreated patients with newly diagnosed ITP, with these cells displaying a pro-inflammatory phenotype, characterised by enhanced expression of CD64 and CD80. After 2 weeks of prednisolone treatment (1 mg/kg daily), the proportion of intermediate MCs reduced, with enhanced expression of the anti-inflammatory markers CD206 and CD163. Healthy control MCs were distinctly different than MCs from patients with ITP before and after GC treatment. Furthermore, the GC-induced phenotype was not observed in patients with chronic ITP receiving thrombopoietin receptor agonists. These data suggest a role of MCs in ITP pathogenesis and clinical response to GC therapy.

The Innate Immune Response Characterizes Posterior Reversible Encephalopathy Syndrome.

While posterior reversible encephalopathy syndrome (PRES) is often characterized by an inflammatory cerebrospinal-fluid (CSF) profile, knowledge of immune cell patterns in PRES is lacking. Thus, we retrospectively characterized CSF and peripheral blood (PB) from 15 PRES patients, which we analyzed by multidimensional flow cytometry (FC). Results were compared to 72 controls, as well as to 9 patients with progressive multifocal leukoencephalopathy (PML, as a relevant differential diagnosis) and 15 multiple sclerosis patients (MS, as a classical neuroinflammatory disorder), respectively. Total protein level in CSF from PRES patients was elevated compared to that in controls, but not to MS and PML. In-depth FC analysis revealed no differences for adaptive immune cells (B cells, plasma cells, CD4+, and CD8+ T cells) in PB or CSF of PRES compared to controls. In contrast, we observed alterations of the adaptive immune response in CSF of PML and MS compared to PRES, indicating that the adaptive immune response is not a driver of disease in PRES. Indeed, PRES was characterized by an innate immune response with CD14++/CD16+ (intermediate) monocytes elevated in PB and CSF, while CD14++/CD16- (classical) monocytes were decreased in PB from PRES patients as compared to controls. Levels of CD14++/CD16+ monocytes correlated with the duration of hospital stay as a surrogate marker for disease severity in PRES patients. Our findings argue for a role of innate rather than adaptive immunity in the pathophysiology of PRES. The observed shift in monocyte subsets might provide valuable diagnostic clues for the clinical management of these patients.

Syncytin-1/HERV-W envelope is an early activation marker of leukocytes and is upregulated in multiple sclerosis patients.

Syncytin-1 is the envelope protein of the human endogenous retrovirus W (HERV-W). It has been related to multiple sclerosis (MS) but its role in cellular immunity and its pathogenic mechanism in the autoimmune context are not fully understood. We analyzed syncytin-1 levels in peripheral blood mononuclear cells (PBMC) subsets from healthy donors, MS patients in relapse or remission, and patients with acute infections by flow cytometry. PBMC cultures were also prepared to analyze protein expression kinetics. MS patients had higher levels of syncytin-1 levels than controls. We found that syncytin-1 is elevated in monocytes during MS relapses and infections. Cells expressing syncytin-1, including monocytes, T and B lymphocytes, and NKs presented mainly an activated phenotype and, upon stimulation with LPS, its levels increased rapidly on antigen-presenting cells. Syncytin-1 ligation promoted the activation of monocytes, as demonstrated by the upregulation of CD80 and the nonclassical subset CD14low CD16+ . Our results suggest an important role for syncytin-1 in the activation of leukocytes. Given that the expression of syncytin-1 is upregulated in MS patients, this protein might be contributing to the autoimmune cascade in the disease.

CD14 (C-159T) polymorphism is associated with increased susceptibility to SLE, and plasma levels of soluble CD14 is a novel biomarker of disease activity: A hospital-based case-control study.

BACKGROUND: Cluster of differentiation 14 (CD14) plays a crucial role in the innate immune response of the host in protection against various pathogens. The importance of soluble CD14 in autoimmune disorders has been described in different populations. However, the role of sCD14 in systemic lupus erythematosus (SLE) is poorly understood. Further, the association of functional variants at the promoter region of the CD14 gene (-159 C > T) with susceptibility to SLE or disease severity needs to be defined. METHODS: Two hundred female SLE patients diagnosed on systemic lupus international collaborating clinics (SLICC) classification criteria and age, sex, matched healthy controls were enrolled in the present study. Polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) method was used to genotype CD14 (C-159 T) polymorphism. Plasma levels of IFN-α, TNF-α, and sCD14 were quantified by enzyme-linked immunosorbent assay (ELISA). RESULTS: Prevalence of mutant genotypes (CT and TT) and minor allele (T) of CD14 (C-159T) polymorphism was significantly higher in SLE cases compared to healthy controls (CT: P < 0.0001; OR = 3.26, TT:P < 0.0001; OR = 3.39; T:P = 0.0009, OR = 1.62). Further, lupus nephritis patients had a higher prevalence of homozygous mutants (TT) and mutant allele (T)(TT: P = 0.0002, OR = 8.07; T: P = 0.001, OR = 1.32). SLE patients displayed significantly increased plasma sCD14, TNF-α, and IFN-α levels in comparison to healthy controls. These cytokines were significantly elevated in patients of lupus nephritis compared to those without kidney involvement. Interestingly, sCD14 levels correlated positively with SLE disease activity index-2K (SLEDAI-2K) scores and 24 hours proteinuria. CONCLUSION: CD14 (C-159T) polymorphism is associated with an increased predisposition to the development of SLE and lupus nephritis: sCD14 is a promising novel biomarker for assessing disease activity and lupus nephritis.

Expanded CD14hiCD16- Immunosuppressive Monocytes Predict Disease Severity in Patients with Acute Pancreatitis.

Mild acute pancreatitis (AP) is a self-limiting disease, whereas severe AP has high mortality because of enhanced systemic inflammation and multiple organ failure. In experimental models of AP, infiltration of monocytes and activation of monocyte-derived macrophages largely determine the severity of the disease. Our previous studies have shown that CD11b+Ly-6Chi inflammatory monocytes were mobilized from bone marrow into peripheral blood and inflamed pancreas during the early stage of AP. However, the phenotype and characteristics of circulating monocytes in patients with AP are not well defined. Fifty patients with AP and nine age- and sex-matched healthy volunteers were enrolled in this study. Compared with those of healthy volunteers, the proportion of CD14hiCD16- monocytes and the level of myeloid-related cytokines/chemokines were increased in AP patients within 48 h after disease onset, especially in patients with a severe disease course. Moreover, the increased monocyte proportions were associated with decreased HLA-DR expression and a reduced T cell count. Notably, dynamic changes in circulating CD14hiCD16- monocytes and their HLA-DR expression, as well as in CD4+ T cells, were obviously different between moderate severe AP and severe AP. Last, area under the receiver operating characteristic analysis showed that the combination of CD14hiCD16- monocyte proportions with their HLA-DR level had higher accuracy for predicting the severity of AP. Taken together, the ratio of CD14hiCD16- monocytes and their HLA-DR level might assist in predicting the severity of disease in AP patients at admission and in monitoring patients' clinical status during recovery.

Immunoproteasome Inhibition Selectively Kills Human CD14+ Monocytes and as a Result Dampens IL-23 Secretion.

MECL-1 (ß2i), LMP2 (ß1i), and LMP7 (ß5i) are the proteolytically active subunits of the immunoproteasome (IP), a special type of proteasome mainly expressed in hematopoietic cells. Targeting the IP in autoimmune diseases proved to be therapeutically effective in preclinical mouse models. In endotoxin-stimulated human PBMCs, IP inhibition reduces the secretion of several proinflammatory cytokines, with the suppression of IL-23 being the most prominent. In this study, we investigated why the production of IL-23, a key mediator of inflammation in autoimmunity, is blocked when the IP is inhibited in LPS-stimulated human PBMCs. CD14+ monocytes could be identified as the main producers of IL-23 in LPS-stimulated PBMCs. We found that IP inhibition with the irreversible LMP7/LMP2 inhibitor ONX 0914 induced apoptosis in CD14+ monocytes, whereas CD4+, CD3+, CD19+, and CD56+ cells remained unaffected. A high expression of IPs renders monocytes susceptible to IP inhibition, leading to an accumulation of polyubiquitylated proteins and the induction of the unfolded protein response. Similar to IP inhibition, inducers of the unfolded protein response selectively kill CD14+ monocytes in human PBMCs. The blockage of the translation in CD14+ monocytes protects these cells from ONX 0914-induced cell death, indicating that the IP is required to maintain protein turnover in monocytes. Taken together, our data reveal why IP inhibition is particularly effective in the suppression of IL-23-driven autoimmunity.

Leishmania infantum (syn. L. chagasi) parasites affect the release of soluble CD14 by infected macrophages.

Functionally, cluster of differentiation 14 (CD14) is a co-receptor of the complex formed by lipopolysaccharide (LPS) and LPS-binding protein expressed on the membrane of a variety of cells. However, CD14 can be shed from the cell membrane into the circulation as soluble CD14 (sCD14) upon cell activation. Previously, our group reported that elevated sCD14 serum levels were associated with the clinical and laboratory findings in the context of visceral leishmaniasis (VL), but not in the context of LPS stimulation or bacterial infection. In the present study, we investigated the secretion dynamics of sCD14 in the context of Leishmania infantum (syn. L. chagasi) in vitro infection. Macrophages from treated VL patients and delayed-type hypersensitivity positive (DTH+) subjects were infected with L. infantum (syn. L. chagasi) promastigotes, and the infection index was evaluated (number of amastigotes per 100 infected macrophages). Additionally, the levels of sCD14, Inteleukin (IL)10, IL-6 and tumour necrosis factor alpha (TNF-α) were measured in the culture supernatants using the Luminex assay. Interestingly, the release of sCD14 was inversely correlated with the L. infantum (syn. L. chagasi) infection index. Of note, the release of sCD14 was upregulated and downregulated in the context of infected macrophages from DTH+ subjects and treated VL patients, respectively. Additionally, we also observed that the levels of sCD14 in the culture supernatants were positively correlated with the levels of TNF-α, IL-6 and IL-10. Therefore, our data suggest that macrophages from treated VL patients and DTH+ subjects respond differently to L. infantum (syn. L. chagasi) infection in the context of the release of sCD14; therefore, the release of sCD14 may be associated with the outcome of VL.

Changes in the Subpopulation Composition and Phagocytic Activity of Monocytes in Patients with Kidney Cancer under the Influence of Metabolites In Vitro.

We studied changes in the subpopulation composition and phagocytic activity of monocytes in patients with kidney cancer under the influence of metabolites of the tumor microenvironment in vitro (lactate, ADP, and glutamate). Incubation with metabolites caused similar shifts in the monocyte subsets in kidney cancer patients (an increase in the relative content of classical CD14++CD16- monocytes and a decrease in the content of the fraction of intermediate CD14++CD16+ monocytes), but different changes in their phagocytic activity. The regulatory effect of metabolites on cells is realized by various mechanisms: receptor, metabolic, and epigenomic. The reactions of monocytes to metabolites in vitro confirm the existence of a distant metabolic effect of the tumor on blood cells that should be taken into account when developing new immunotherapeutic methods.

Breastfed at Tiffany's.

The importance of breast milk for the growing infant is undisputed; breastfeeding decreases infantile mortality by tenfold and decreases the incidence of infectious diseases. Despite its recognized benefits, the structural richness of breast milk has also impeded the characterization of the multiple effects of milk components on infant physiology. However, the important roles of some components of breast milk are beginning to be dissected. For instance, molecules such as immunoglobulin A (IgA) and milk oligosaccharides protect from gastrointestinal infections and influence the development of the gut microbiota. Deciphering the complex composition of breast milk brings to light multifaceted contributions that combine to make breast milk the ultimate personalized medicine.

Complement C1q synergizes with PTX3 in promoting NLRP3 inflammasome over-activation and pyroptosis in rheumatoid arthritis.

Excessive inflammatory cytokines play crucial roles in the pathogenesis of rheumatoid arthritis (RA), however, the underlying mechanism remains unclear. In this study, we demonstrated that pentaxin 3 (PTX3), an essential component of innate immunity, was elevated in RA and preferentially bound to CD14+ monocytes. C1q promoted the binding and resulted in increased cell proliferation, activation and caspase-1-related late apoptotic cells (7-AAD+annexin V+), as well as enhanced release of inflammatory cytokines including TNF-α, IL-1ß and IL-6. Serum from RA patients, compared with healthy controls, induced gasdermin D (GSDMD)-dependent pyroptosis in monocytes, and this ability was associated with disease activity. Moreover, PTX3 synergized with C1q to promote pyroptosis in RA-serum pre-incubated monocytes by coordinately enhancing NLRP3 inflammasome over-activation and inducing GSDMD cleavage, cell swelling with large bubbles, caspase-1-dependent cell death and inflammatory cytokine release including IL-6. On the other hand, IL-6 promoted PTX3 plus C1q-induced pyroptosis in both normal and RA serum pre-incubated monocytes. These findings collectively implicated an important role of IL-6 in driving PTX3 plus C1q-mediated pyroptosis in RA and shed lights on a potential new treatment strategy targeting pyroptosis-mediated persistent inflammatory cytokine release.