Chemotaxis Research Articles

Vilobelimab, a first-in-class, human-mouse chimeric immunoglobulin G4 (IgG4) kappa monoclonal antibody, targets human complement component 5a (C5a) in plasma. Unlike upstream complement inhibitors, vilobelimab does not inhibit the generation of the membrane attack complex (C5b-9), necessary to mitigate certain infections. C5a is a strong anaphylatoxin and chemotactic agent that plays an essential role in both innate and adaptive immunity. Elevated levels of C5a have been associated with pathologic processes, including sepsis and inflammatory respiratory disorders such as acute respiratory distress syndrome (ARDS). Blocking C5a with vilobelimab has shown therapeutic promise. A randomized, multicenter placebo-controlled Phase III study of vilobelimab in patients with severe COVID-19 (PANAMO) found that patients treated with vilobelimab had a significantly lower risk of death by day 28 and 60. Based on this study, the United States Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for Gohibic® (vilobelimab) injection for the treatment of COVID-19 in hospitalized adults when initiated within 48 h of receiving invasive mechanical ventilation (IMV) or extracorporeal membrane oxygenation (ECMO). In January 2025, the European Commission (EC) granted marketing authorization for Gohibic® (vilobelimab) for the treatment of adult patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-induced ARDS who are receiving systemic corticosteroids as part of standard of care and receiving IMV with or without ECMO. Herein, we review the mechanism of action of vilobelimab in selectively inhibiting C5a-induced inflammation, outlining its bench-to-bedside development from the fundamental biology of the complement system and preclinical evidence through to the clinical data demonstrating its life-saving potential in the management of COVID-19-induced ARDS.

BackgroundGlioblastoma (GBM) is a highly aggressive brain tumor with poor prognosis and limited treatment options. Oncolytic virus (OV) therapy holds promise but is hindered by immune neutralization and poor tumor infiltration. Neural stem cells (NSCs) can enhance OV delivery, and intracerebroventricular (ICV) administration offers broader tumor access. This study evaluates NSC-OV therapy via ICV injection for improved tumor targeting and immune modulation in GBM.MethodsNSCs were infected with OV and assessed for viral uptake and replication. In vitro assays examined NSC-OV effects on glioma proliferation and migration. In vivo xenograft and orthotopic models evaluated tumor targeting, therapeutic efficacy, and immune modulation. Humanized immune system mouse models enabled single-cell RNA sequencing and flow cytometry analysis of immune responses.ResultsNSCs retained their stemness after OV infection. NSCs-OV significantly inhibited glioma cell migration, proliferation, and colony formation in vitro. In orthotopic GBM models, NSCs-OV exhibited enhanced tumor homing, prolonged viral persistence, and reduced tumor burden while minimizing inflammation and systemic toxicity. NSCs protected OV from neutralizing antibodies, leading to sustained efficacy. Single-cell RNA sequencing indicated that NSCs-OV therapy reduced tumor-promoting inflammation by downregulating S100A8/A9, markers of myeloid-derived suppressor cells (MDSCs) and chemotactic factors that recruited MDSCs into tumors. Combining NSCs-OV with Paquinimod further suppressed tumor growth by reducing MDSCs and increasing activated T cells.ConclusionsNSCs serve as efficient OV carriers, enhancing tumor targeting, suppressing GBM progression, and modulating the immune landscape. The combination with Paquinimod amplifies therapeutic benefits, offering a promising strategy for improving GBM treatment outcomes.

IntroductionThe transition from inflammation to proliferation is a critical but poorly understood phase in wound healing. To elucidate the cellular and molecular dynamics of this pivotal stage, we performed single-cell RNA sequencing (scRNA-seq) on mouse skin biopsies 4 days after injury.MethodsBy employing our newly developed R packages, OptiRes for optimized clustering and TidyGenePlot for annotation, we identified 21 distinct cell types. CellChat analysis was used to identify intercellular communication clusters. Findings on chemotactic signaling through CCR5, CCR1, and ACKR1 were validated in vivo, and the functional significance was confirmed by demonstrating that inhibition of CCR pathways reduced phagocyte infiltration. ResultsOur analysis revealed a dynamic shift in cellular composition, characterized by an influx of neutrophils, classical monocytes, and M1 macrophages. This recruitment of phagocytes was driven by enhanced chemotactic signaling through CCR5, CCR1, and ACKR1. Furthermore, CellChat analysis identified four distinct intercellular communication clusters, highlighting the early activation of VEGF and EGF signaling pathways, which are essential for angiogenesis and re-epithelialization. DiscussionTogether, these findings provide a high-resolution map of the cellular and molecular landscape during the transition from inflammation to proliferation, offering novel insights into the mechanisms that orchestrate tissue repair and identifying potential intervention manner to enhance wound healing.

S100A9 as a potential novel target for neuromyelitis optica spectrum disorder.

Protein misfolding, aggregation and other factors determining the amyloidogenic landscape of human leucocyte chemotaxin-2: A review.

Cholangiocarcinoma-derived secreted products and growth arrest-specific 2-like 3 enhance migratory and invasive abilities of fibroblasts.

Movement of leukocytes from the circulatory system into a site of inflammation is a highly complex process. The migration of neutrophils into the lumen of the mammary gland during mastitis is no exception. There is information about the involvement of bacterial-produced products during this process, but less is known regarding the role of host products. Two bovine cell lines, a primary mammary gland endothelial cell line and an immortalized bovine mammary gland epithelial cell line (Mac-T), along with freshly isolated bovine neutrophils, were used to study this further. The cell lines were grown on inserts and in wells of tissue-culture plates. In the initial set of experiments, neutrophils were added to the inserts, and then their migration into the tissue-culture plate wells was monitored using a hemocytometer or a flow cytometer. Lipopolysaccharide was added to some of the wells to induce migration. This was then followed by a similar series of experiments that were initialized by the addition of inhibitors to interleukin-8 (IL-8), platelet-activating factor (PAF), tumor-necrosis factor-α (TNF-α), or lipoxygenase (LOX) prior to the addition of the neutrophils and their enumeration. In addition, integrin expression (CD11a/18) by the neutrophils was measured using flow cytometry. In our insert/tissue culture plate well system, neutrophils readily migrated towards the epithelial cells when they were separated from them either by the insert alone or the insert plus a layer of endothelial cells. The presence of LPS in the system allowed this migration to occur without the involvement of epithelial cells. The inhibition of PAF or TNF alone did not alter migration, while the inhibition of either IL-8 or LOS did significantly reduce the movement of neutrophils. Only the migrating neutrophils had upregulated levels of CD11a/18 on their surface. From a host perspective, it appears that products of the LOX enzyme system and IL-8 were the primary inducers of neutrophil migration, and that mammary gland epithelial cells were capable of driving this process on their own. Understanding the role of host-produced chemotactic agents that are involved in mammary gland inflammation may allow better regulation of this activity.

27-Hydroxycholesterol (27-HC) is an oxidative metabolite of cholesterol and an oxysterol catalysed by the mitochondrial cytochrome P450 enzyme, sterol 27-hydroxylase (CYP27A1). In addition to inducing the release of eosinophil chemotactic factors such as RANTES and Eotaxin, 27-HC enhances the differentiation of lung fibroblasts into myofibroblasts and promotes the production of extracellular matrix proteins. Therefore, it is possible that 27-HC may play a significant role in the pathogenesis of asthma. In this study, we observed elevated expression of CYP27A1 and increased production of 27-HC in the lung tissues of asthmatic mice, with alveolar macrophages (AMs) identified as the primary source of 27-HC. 27-HC induced an increase in total cell count and eosinophil number in the bronchoalveolar lavage fluid of asthmatic mice, exacerbated inflammatory cell infiltration into lung tissues, and heightened airway hyper-responsiveness, thereby aggravating asthma. The alarmin, IL-33, within airways induced 27-HC production by AMs via the NF-κB signalling pathway. Furthermore, 27-HC was shown to inhibit the phagocytosis of apoptotic cells (efferocytosis) by airway epithelial cells (AECs) through AMPK activation. Thus, in asthmatic mice, 27-HC, predominantly derived from AMs, influences the efferocytotic function of AECs, demonstrating that cross-talk between macrophages and epithelial cells regulates asthma pathogenesis. This study provides valuable insight into the molecular mechanisms underlying asthma and offers theoretical and experimental data for identifying novel therapeutic targets for clinical asthma management.

BRD4 is an epigenetic reader protein that regulates oncogenes such as myc in cancer. However, its additional role in shaping immune responses via regulation of inflammatory and myeloid cell responses is not yet fully understood. This work further characterized the multifaceted role of BRD4 in antitumor immunity. Nanostring gene expression analysis of EMT6 tumors treated with a BRD4 inhibitor identified a reduction in myeloid gene expression signatures. Additionally, BRD4 inhibition significantly reduced myeloid-derived suppressor cells (MDSCs) in the spleens and tumors of mice in multiple tumor models and also decreased the release of tumor-derived MDSC growth and chemotactic factors. Pharmacologic inhibition of BRD4 in MDSCs induced apoptosis and modulated expression of apoptosis regulatory proteins. A BRD4 myeloid–specific knockout model suggested that the dominant mechanism of MDSC reduction after BRD4 inhibition was primarily through a direct effect on MDSCs. BRD4 inhibition enhanced anti–PD-L1 therapy in the EMT6, 4T1, and Lewis lung carcinoma tumor models, and the efficacy of the combination treatment was dependent on CD8+ T cells and on BRD4 expression in the myeloid compartment. These results identify BRD4 as a regulator of MDSC survival and provide evidence to further investigate BRD4 inhibitors in combination with immune-based therapies.

Tumor cell-derived microparticles containing MTX (MTX-TMPs) in the treatment of cholangiocarcinoma by modulating MDSCs.

Collagen-based hydrogel encapsulated with SDF-1α microspheres accelerate diabetic wound healing in rats.

Leukocyte chemotactic factor 2 (ALECT2) amyloidosis is an emerging but under-recognized cause of CKD, typically presenting with slowly progressive renal dysfunction and no specific treatment modality. Unlike amyloid light chain (AL) or amyloid A (AA) amyloidosis, ALECT2 primarily exhibits interstitial amyloid deposition without systemic involvement. We report a case series patients with ALECT2 amyloidosis, with some of whom demonstrate rare and previously unreported associations. These cases highlight the heterogeneity in clinical presentation, ranging from nephrotic syndrome to AKI and even possible graft dysfunction. Diagnosis was confirmed in all cases through renal biopsy. Disease progression varied depending upon associated disease. This series expands the ALECT2 amyloidosis spectrum and underscores the need for increased awareness

BackgroundRheumatoid arthritis is a chronic, inflammatory, and symmetrical peripheral polyarthritis often associated with extra-articular manifestations, that end in marked functional impairment. Chemokines, such as monocyte chemotactic protein-1, are not only potential therapeutic targets but also play a crucial role in leukocyte migration within chronic inflammatory diseases. This migration contributes to synovitis and ultimately plays a critical role in the pathogenesis of rheumatoid arthritis. The purpose of this study was to evaluate monocyte chemotactic factor-1 serum levels and its association with RA disease activity score 28. This cross-sectional study included 306 patients aged 18–80 years. Clinical arthritic activity was assessed using swollen joint count, tender joint count, and disease activity score 28, while monocyte chemotactic protein-1, erythrocyte sedimentation rate, or C-reactive protein were used as laboratory biomarkers.ResultsThe mean age of the patients was 53.7 ± 13.6 years, with a female predominance (191/306, 63%). Monocyte chemotactic protein-1correlated with clinical and radiographic parameters of disease activity & progression, whereas C-reactive protein and erythrocyte sedimentation rate correlated with all clinical parameters except tender joint count. Disease activity score 28 monocyte chemotactic protein-1 showed a significant correlation with Disease Activity Score 28 C-reactive protein (r = 0.678) and Disease Activity Score 28 erythrocyte sedimentation rate (r = 0.311) after one year. Disease activity score 28 monocyte chemotactic protein-1 showed a highly significant association with predictive progression (AUC = 0.926).ConclusionThe findings of this study suggest that Disease Activity Score 28 and monocyte chemotactic protein-1 may serve as reliable clinical indicators to assess rheumatoid arthritis disease activity and monitor its progression.

ABSTRACTThe precise molecular mechanisms underlying angioedema attacks in cases of C1‐inhibitor‐deficient hereditary angioedema (C1‐INH‐HAE), angiotensin‐converting enzyme inhibitor‐induced angioedema (ACEi‐AE), and mast cell‐/histamine‐mediated angioedema (Hist‐AE) are not well understood. These attacks may involve immune and inflammatory mechanisms. We compared serum biomarkers indicating vascular integrity, leakage, angiogenesis, coagulation, and inflammation. During an attack‐free period, we assessed 34 markers simultaneously using multi‐ and/or singleplex ELISA in 25 patients with C1‐INH‐HAE, 17 with ACEi‐AE, 25 with Hist‐AE, and 23 healthy controls. Differential blood counts, C1‐INH‐HAE‐specific laboratory parameters, and recently developed assays addressing early complement and lectin pathways were included. The results revealed significant differences, as well as some similarities. Tie‐2, VEGFs, C1s/C1INHc appear to play a role in all AE types regardless of whether they are bradykinin‐ or histamine‐mediated. Furthermore, evidence was found for a role of IL‐17, eosinophil, and neutrophil chemotactic factors, and the activation of these granulocytes was found. MASP‐1/C1‐INHc indicated early activation of the lectin pathway in ACEi‐AE and HistAE, but not in C1‐INH‐HAE. C1s/C1‐INHc and MASP‐1/C1INHc ratio was able to discriminate C1‐INH‐HAE from controls and the other AE types. Future investigations in C1‐INH‐HAE, ACEi‐AE, and Hist‐AE should not only focus on complement activation but also the interaction with granulocytes.

Retained placenta (RP) is a common reproductive disorder with complex etiology and pathogenesis, affecting approximately 8% of dairy cows during the periparturient period. Macrophages constitute 20% to 25% of all leukocytes at the maternal-fetal interface and coordinate several processes critical for fetal membrane expulsion, including tissue remodeling, induction of apoptosis in damaged cells, and immune activation. This study aimed to investigate the morphological changes at the maternal-fetal interface, as well as the quantity, distribution, and polarization of caruncle macrophages in cows with and without RP. Furthermore, we discuss the potential association between macrophage alterations and histopathological changes in placental tissue of RP cows. A total of 80 Holstein dairy cows (parity 2-4) were enrolled in this study. Blood samples were collected at -7 d before the expected calving date, at calving, at 12 h postpartum, and at 7 d postpartum. Placental tissue samples were collected within 30 min after parturition. Based on whether the placental membranes were expelled within 12 h postpartum, cows were classified retrospectively into normal expulsion (NE; n = 6) and RP (n = 6) groups. Picrosirius red staining, along with elevated mRNA and protein levels of collagen III, indicated enhanced collagen fiber deposition in caruncle tissue. In addition, the mRNA expression of matrix metalloproteinases (MMP2 and MMP9) was downregulated in RP tissues, whereas TIMP1 was upregulated. Compared with NE cows, the apoptosis index and the protein and mRNA levels of pro-apoptotic factors (BAX, Caspase 3, Caspase 8) were lower in cows with RP, and the anti-apoptotic factor (BCL2) was higher, indicating reduced apoptosis in the caruncle tissue from RP cows. In both the serum and tissues, we observed lower levels of chemotactic factors (CXCL1 and MCP-1) in RP cows, alongside increased IL-10 (an immunosuppressive factor) and decreased IL-1β (an immune-stimulatory factor). The downregulated protein and mRNA abundance of the macrophage marker CD68, consistent with reduced presence of CD68+ cells observed through immunofluorescence, revealed low numbers of caruncle macrophages in cows with RP. Further, the caruncles tissue of RP cows displayed significant alterations in the distribution of CD68+ macrophages, with reduced infiltration into trophoblast cells. Regarding macrophage phenotypic changes in RP cows, the greater protein and mRNA expression of M2 polarization markers (CD206, IL-10, IL-6, and TGF-β), along with greater numbers of CD206+/CD68+ cells detected through immunofluorescence, indicated that macrophage polarization phenotype in the caruncles of RP cows shifted predominantly toward the M2 phenotype. In contrast, RP cows exhibited lower protein and mRNA levels of M1 polarization markers (CD86, inducible nitric oxide synthase, IL-1β, and NF-κB), as well as reduced numbers of CD86+/CD68+ cells. Overall, caruncle tissues from RP cows were characterized by a reduced macrophage population with a predominant M2 phenotype. Alterations in the quantity and polarization state of macrophages at the maternal-fetal interface may lead to reduced immune cell trafficking into the caruncle, thus impairing the apoptotic and proteolytic processes essential for placental expulsion.

Intervertebral disc (IVD) degeneration (IVDD) is a major contributor to chronic low back pain, representing a substantial burden on the spinal healthcare system and serving as a leading cause of long-term disability worldwide. Biomimeticin vitromodels that accurately replicate histological characteristics, three-dimensional structures, and multicellular interactions are lacking. Consequently, monocultures of cell lines and two-dimensional culture models are still used to study the pathomechanisms of IVDD. We established functional multicellular IVD spheroid cultures using primary human annulus fibrosus and nucleus pulposus cells. The spheroids maintained the IVD-specific phenotype, including hypoxic conditions and lamellar structures. Additionally, the spheroid markedly increased the expression level of inflammatory mediators and chemokines in the presence of the pro-inflammatory cytokine IL-1β, a master regulator of IVDD. Furthermore, we implemented our microfluidic chemotaxis platform to investigate microglial neuroinflammation in response to our reconstituted IVD spheroid models. Transcriptome sequencing revealed that microglia stimulated by potential contributing factors derived from IVDD spheroids exhibited a significant upregulation of the expression levels of chemotactic factors and cytokines including CCL-2, -3, -4, -5, IL-8 and IL-6 (p< 0.05). Moreover, we observed considerable activation and infiltration of microglia induced by soluble factors derived from IVDD spheroids, which are expected to occur during IVDD. The chemotactic effects on microglia were reduced upon the neutralization of CCL-2 or IL-8 or inhibition of NF-κB signaling. These robustin vitroIVD spheroids can be used to model IVDD and provide a valuable platform for the assessment and development of IVDD therapeutics.

The NLRP3 inflammasome, prominently expressed in macrophages, has garnered significant attention as a contributing factor to graft-versus-host disease (GVHD). In this study, we established an allogeneic hematopoietic cells transplantation mice model using NLRP3 knockout (NLRP3-/-) and wild-type C57BL/6 mice as recipients to investigate the impact underlying mechanisms of NLRP3 deficiency on gut GVHD. Results clearly revealed that NLRP3-/- recipients exhibited reduced gut inflammation infiltration, accompanied by an increased number of Tregs and accelerated white blood cell recovery. Moreover, the loss of NLRP3 function led to decreased protein levels of macrophage-related molecules in the gut, such as interleukin 1β (IL-1β), caspase-1, CD68 and CD11b, alongside an augmented presence of M2 macrophages in the bone marrow. In vitro experiments using bone marrow-derived macrophages (BMDMs) confirmed that NLRP3 deficiency led to lower levels of inflammasome-dependent cytokines IL-1β, pan-inflammatory factors IL-6, and chemotactic factors CCL3/CCL4. Furthermore, NLRP3-/- in BMDMs demonstrated an ability to effectively induce apoptosis and increase the proportion of Tregs in the mixed lymphocyte reaction system. Overall, our study elucidates the significance of macrophages in regulating gut inflammation through the NLRP3 inflammasome pathway, highlighting the potential therapeutic benefits of targeting NLRP3 or macrophages in the treatment of GVHD.

Introduction and Objective: Insulin resistance (IR) in obesity and type 2 diabetes causes endothelial dysfunction (ECD), an early marker of cardiovascular disease (CVD). In lipodystrophy (LD), IR is pathway selective, thus insulin signaling is increased in some signal transduction pathways and decreased in others. By contrast, rare mutations of the insulin receptor gene (INSR) block all insulin signal transduction pathways. To determine effects of LD and INSR on ECD, we used CD34+ hematopoietic progenitor cells as biomarkers of endothelial health. We hypothesize that ECD is greater in LD vs INSR due to a combination of deficient and excess insulin signal transduction in LD. Methods: Prospective cross-sectional study of patients with LD and INSR aged ≥18 y. CD34+ were harvested from fasting peripheral blood derived mononuclear cells (MNCs). Cell number, colony count formation (CFU), and migratory function (in response to a chemotactic factor) were evaluated. Groups were compared by Mann-Whitney test and correlations by Pearson. Results: 8 patients had INSR (mean age, 28±6 years; female, 63%; white, 38%; 3 heterozygous, 5 homozygous) vs 6 with LD (mean age, 38±17 years; female, 100%; white, 67%; 5 partial, 1 generalized). In patients with INSR and LD, respectively, MNCs/mL were 3.4x106±1.8x106 cells/mL vs 3.2x106±1.3x106 cells/mL (P=0.95); CD34+ cell numbers were 5.5x105±4.3x105 cells/mL vs 5.2x105±5.4x105 cells/mL (P=0.75); CD34+:MNCs ratios were, 0.23±0.25 vs 0.20±0.25 (P=0.7); CFU were 5.8±3.5 vs 5.0±1.4 (P=0.9); migration was 1.1±0.3 vs 0.9±0.1 (P=0.1). In the combined cohort, CFU positively correlated with insulin (r=0.62, P=0.03). Conclusion: Patients with INSR and LD had comparable measures of ECD, but sample size was small. By investigating pro- and anti-atherogenic actions of insulin on the vasculature, this study can enhance understanding of mechanisms underlying CVD in the general population. Disclosure F.D. Rodriguez-Ramos: None. S. Nandula: None. M. Vu: None. R. Brown: Research Support; Chiesi, Regeneron Pharmaceuticals, Marea. S. Sen: None.

ABSTRACTThe role of CD8+ T cells in the pathogenesis of ulcerative colitis (UC) remains unclear. Similarly, the posttranscriptional regulation of the highly heterogenic CD8+ T cell populations and their effector function in IBD also remains poorly understood. Here, we find that miR‐29a and ‐29b (miR‐29a/b) regulate T cell fate, and their expression is higher near damaged colon tissue in patients with IBD compared to controls. In mice, we find that miR‐29a/b suppresses the differentiation of CD8+ T cells and the secretion of pro‐inflammatory and chemotactic factors during severe colitis by inhibiting transcriptional pathways, including those involving the T cell receptor and JAK‐STAT signaling. Furthermore, we identify Ifng, an inflammatory factor that drives immune response and the reshaping of CD8+ T cell fate, as a potential target of the miRNAs. Finally, we show that delivery of miR‐29 mimics to the colon of mice is sufficient to alleviate DSS‐induced inflammation. Together, these data show that miR‐29 plays an important role in suppressing T cell overactivation during inflammatory diseases.

The role of periodontal ligament stem cells (PDLSCs) and dental pulp stem cells (DPSCs) in stimulating angiogenesis has been reported, but their angiogenetic potential has not been directly compared. In this work, paired PDLSCs and DPSCs, i.e., derived from the same donor, were tested for their immunophenotype and multi-differentiation capabilities, with particular emphasis on their pro-angiogenic activity. Flow cytometry was utilized to study the expression of mesenchymal stem cell, pericyte, and endothelial markers, while gene expression was evaluated through real-time PCR. The angiogenic potential was assessed recurring to tubulogenesis assay, co-cultures with Human Microvascular Endothelial Cell (HMEC-1), and VEGF-A quantification. The immunophenotype of DPSCs and PDLSCs was different in CD146+ and CD31+ cell subsets, but both cell types promoted HMEC-1 tubulogenesis in vitro. Consistently, VEGF-A gene expression level and its quantification in cell-conditioned media of PDLSCs and DPSCs was comparable between them, and both promoted the formation of vessel-like structures, when co-cultured with HMEC-1 cells. All together, these results showed the heterogeneity of PDLSCs and DPSCs, which are constituted of different cellular subsets, likely modulated by the microenvironmental cues. PDLSCs and DPSCs showed comparable pro-angiogenic activity, enhanced by the contemporary expression of angiogenic and chemotactic factors.