Gut microbiota as a key regulator of intestinal mucosal immunity

Gut microbiota is a complex microbial community with the ability of maintaining intestinal health. Intestinal homeostasis largely depends on the mucosal immune system to defense external pathogens and promote tissue repair. In recent years, growing evidence revealed the importance of gut microbiota in shaping intestinal mucosal immunity. Therefore, according to the existing findings, this review first provided an overview of intestinal mucosal immune system before summarizing the regulatory roles of gut microbiota in intestinal innate and adaptive immunity. Specifically, this review delved into the gut microbial interactions with the cells such as intestinal epithelial cells (IECs), macrophages, dendritic cells (DCs), neutrophils, and innate lymphoid cells (ILCs) in innate immunity, and T and B lymphocytes in adaptive immunity. Furthermore, this review discussed the main effects of gut microbiota dysbiosis in intestinal diseases and offered future research prospects. The review highlighted the key regulatory roles of gut microbiota in intestinal mucosal immunity via various host-microbe interactions, providing valuable references for the development of microbial therapy in intestinal diseases.

Neurotoxic effects of polystyrene nanoplastics on memory and microglial activation: Insights from in vivo and in vitro studies

Nanoplastics, arising from the fragmentation of plastics into environmental pollutants and specialized commercial applications, such as cosmetics, have elicited concerns due to their potential toxicity. Evidence suggests that the oral ingestion of nanoplastics smaller than 100 nm may penetrate the brain and induce neurotoxicity. However, comprehensive research in this area has been hampered by technical challenges associated with the detection and synthesis of nanoplastics. This study aimed to bridge this research gap by successfully synthesizing fluorescent polystyrene nanoplastics (PSNPs, 30-50 nm) through the incorporation of IR-813 and validating them using various analytical techniques. We administered PSNPs orally (10 and 20 mg/kg/day) to mice and observed that they reached brain tissues and induced cognitive dysfunction, as measured by spatial and fear memory tests, while locomotor and social behaviors remained unaffected. In vitro studies (200 μg/mL) demonstrated a predominant uptake of PSNPs by microglia over astrocytes or neurons, leading to microglial activation, as evidenced by immunostaining of cellular markers and morphological analysis. Transcriptomic analysis indicated that PSNPs altered gene expression in microglia, highlighting neuroinflammatory responses that may contribute to cognitive deficits. To further explore the neurotoxic effects of PSNPs mediated by microglial activation, we measured endogenous neuronal activity using a multi-electrode array in cultured hippocampal neurons. The application of conditioned media from microglia exposed to PSNPs suppressed neuronal activity, which was reversed by inhibitors of microglial activation. Our findings offer detailed insights into the mechanisms by which nanoplastics damage the brain, particularly emphasizing the potential environmental risk factors that contribute to cognitive impairment in neurodegenerative diseases.

Timosaponin BⅡ reduces colonic inflammation and alleviates DSS-induced ulcerative colitis by inhibiting NLRP3

ETHNOPHARMACOLOGICAL RELEVANCE

The Timosaponin BⅡ (TBⅡ) is one of the main active components of the traditional Chinese medicine Anemarrhena asphodeloides, and it is a steroidal saponin with various pharmacological activities such as anti-oxidation, anti-inflammatory and anti-apoptosis. However, its role in acute ulcerative colitis remains unexplored thus far.

AIM OF THE STUDY

This study aims to investigate the protective effect of TBⅡ against dextran sulfate sodium (DSS)-induced ulcerative colitis in mice and elucidate its underlying mechanisms.

METHODS

Wild-type (WT) and NLRP3 knockout (NLRP3-/-) mice were applied to evaluate the protective effect of TBⅡ in DSS-induced mice colitis. Pharmacological inhibition of NLRP3 or adenovirus-mediated NLRP3 overexpression in bone marrow-derived macrophages (BMDM) from WT mice and colonic epithelial HCoEpiC cells was used to assess the role of TBⅡ in LPS + ATP-induced cell model. RNA-seq, ELISA, western blots, immunofluorescence staining, and expression analysis by qPCR were performed to examine the alterations of colonic NLRP3 expression in DSS-induced colon tissues and LPS + ATP-induced cells, respectively.

RESULTS

In mice with DSS-induced ulcerative colitis, TBⅡ treatment attenuated clinical symptoms, repaired the intestinal mucosal barrier, reduced inflammatory infiltration, and alleviated colonic inflammation. RNA-seq analysis and protein expression levels demonstrated that TBⅡ could prominently inhibit NLRP3 signaling. TBⅡ-mediated NLRP3 inhibition was associated with alleviating intestinal permeability and inflammatory response via the blockage of communication between epithelial cells and macrophages, probably in an NLRP3 inhibition mechanism. However, pharmacological inhibition of NLRP3 by MCC950 or Ad-NLRP3 mediated NLRP3 overexpression significantly impaired the TBⅡ-mediated anti-inflammatory effect. Mechanistically, TBⅡ-mediated NLRP3 inhibition may be partly associated with the suppression of NF-κB, a master pro-inflammatory factor for transcriptional regulation of NLRP3 expression in the priming step. Moreover, co-treatment TBⅡ with NF-κB inhibitor BAY11-7082 partly impaired TBⅡ-mediated NLRP3 inhibition, and consequently affected the IL-1β mature and secretion. Importantly, TBⅡ-mediated amelioration was not further enhanced in NLPR3-/- mice.

CONCLUSION

TBⅡ exerted a prominent protective effect against DSS-induced colitis via regulation of alleviation of intestinal permeability and inflammatory response via the blockage of crosstalk between epithelial cells and macrophages in an NLRP3-mediated inhibitory mechanism. These beneficial effects could make TBⅡ a promising drug for relieving colitis.

The impact of the P2X7 receptor on the tumor immune microenvironment and its effects on tumor progression

Cancer is a significant global health concern, and finding effective methods to treat it has been a focus of scientific research. It has been discovered that the growth, invasion, and metastasis of tumors are closely related to the environment in which they exist, known as the tumor microenvironment (TME). The immune response interacting with the tumor occurring within the TME constitutes the tumor immune microenvironment, and the immune response can lead to anti-tumor and pro-tumor outcomes and has shown tremendous potential in immunotherapy. A channel called the P2X7 receptor (P2X7R) has been identified within the TME. It is an ion channel present in various immune cells and tumor cells, and its activation can lead to inflammation, immune responses, angiogenesis, immunogenic cell death, and promotion of tumor development. This article provides an overview of the structure, function, and pharmacological characteristics of P2X7R. We described the concept and components of tumor immune microenvironment and the influence immune components has on tumors. We also outlined the impact of P2X7R regulation and how it affects the development of tumors and summarized the effects of drugs targeting P2X7R on tumor progression, both past and current, assisting researchers in treating tumors using P2X7R as a target.

The roles of ABCB1/P-glycoprotein drug transporters in regulating gut microbes and inflammation: insights from animal models, old and new

Commensal enteric bacteria have evolved systems that enable growth in the ecologic niche of the host gastrointestinal tract. Animals evolved parallel mechanisms to survive the constant exposure to bacteria and their metabolic by-products. We propose that drug transporters encompass a crucial system to managing the gut microbiome. Drug transporters are present in the apical surface of gut epithelia. They detoxify cells from small molecules and toxins (xenobiotics) in the lumen. Here, we review what is known about commensal structure in the absence of the transporter ABCB1/P-glycoprotein in mammalian models. Knockout or low-activity alleles of ABCB1 lead to dysbiosis, Crohn's disease and ulcerative colitis in mammals. However, the exact function of ABCB1 in these contexts remain unclear. We highlight emerging models-the zebrafish Danio rerio and sea urchin Lytechinus pictus-that are poised to help dissect the fundamental mechanisms of ATP-binding cassette (ABC) transporters in the tolerance of commensal and pathogenic communities in the gut. We and others hypothesize that ABCB1 plays a direct role in exporting inflammatory bacterial products from host epithelia. Interdisciplinary work in this research area will lend novel insight to the transporter-mediated pathways that impact microbiome community structure and accelerate the pathogenesis of inflammatory bowel disease when perturbed. This article is part of the theme issue 'Sculpting the microbiome: how host factors determine and respond to microbial colonization'.

Dynamic immune recovery process after liver transplantation revealed by single-cell multi-omics analysis

Elucidating the temporal process of immune remodeling under immunosuppressive treatment after liver transplantation (LT) is critical for precise clinical management strategies. Here, we performed a single-cell multi-omics analysis of peripheral blood mononuclear cells (PBMCs) collected from LT patients (with and without acute cellular rejection [ACR]) at 13 time points. Validation was performed in two independent cohorts with additional LT patients and healthy controls. Our study revealed a four-phase recovery process after LT and delineated changes in immune cell composition, expression programs, and interactions along this process. The intensity of the immune response differs between the ACR and non-ACR patients. Notably, the newly identified inflamed NK cells, CD14+RNASE2+ monocytes, and FOS-expressing monocytes emerged as predictive indicators of ACR. This study illuminates the longitudinal evolution of the immune cell landscape under tacrolimus-based immunosuppressive treatment during LT recovery, providing a four-phase framework that aids the clinical management of LT patients.

Tethering of soluble immune effectors to mucin and chitin reflects a convergent and dynamic role in gut immunity

The immune system employs soluble effectors to shape luminal spaces. Antibodies are soluble molecules that effect immunological responses, including neutralization, opsonization, antibody-dependent cytotoxicity and complement activation. These molecules are comprised of immunoglobulin (Ig) domains. The N-terminal Ig domains recognize antigen, and the C-terminal domains facilitate their elimination through phagocytosis (opsonization). A less-recognized function mediated by the C-terminal Ig domains of the IgG class of antibodies (Fc region) involves the formation of multiple low-affinity bonds with the mucus matrix. This association anchors the antibody molecule to the matrix to entrap potential pathogens. Even though invertebrates are not known to have antibodies, protochordates have a class of secreted molecules containing Ig domains that can bind bacteria and potentially serve a similar purpose. The VCBPs (V region-containing chitin-binding proteins) possess a C-terminal chitin-binding domain that helps tether them to chitin-rich mucus gels, mimicking the IgG-mediated Fc trapping of microbes in mucus. The broad functional similarity of these structurally divergent, Ig-containing, secreted effectors makes a case for a unique form of convergent evolution within chordates. This opinion essay highlights emerging evidence that divergent secreted immune effectors with Ig-like domains evolved to manage immune recognition at mucosal surfaces in strikingly similar ways. This article is part of the theme issue 'Sculpting the microbiome: how host factors determine and respond to microbial colonization'.

When the microbiome shapes the host: immune evolution implications for infectious disease

The microbiome includes both 'mutualist' and 'pathogen' microbes, regulated by the same innate immune architecture. A major question has therefore been: how do hosts prevent pathogenic infections while maintaining beneficial microbes? One idea suggests hosts can selectively activate innate immunity upon pathogenic infection, but not mutualist colonization. Another idea posits that hosts can selectively attack pathogens, but not mutualists. Here I review evolutionary principles of microbe recognition and immune activation, and reflect on newly observed immune effector-microbe specificity perhaps supporting the latter idea. Recent work in Drosophila has found a surprising importance for single antimicrobial peptides in combatting specific ecologically relevant microbes. The developing picture suggests these effectors have evolved for this purpose. Other defence responses like reactive oxygen species bursts can also be uniquely effective against specific microbes. Signals in other model systems including nematodes, Hydra, oysters, and mammals, suggest that effector-microbe specificity may be a fundamental principle of host-pathogen interactions. I propose this effector-microbe specificity stems from weaknesses of the microbes themselves: if microbes have intrinsic weaknesses, hosts can evolve effectors that exploit those weaknesses. I define this host-microbe relationship as 'the Achilles principle of immune evolution'. Incorporating this view helps interpret why some host-microbe interactions develop in a coevolutionary framework (e.g. Red Queen dynamics), or as a one-sided evolutionary response. This clarification should be valuable to better understand the principles behind host susceptibilities to infectious diseases. This article is part of the theme issue 'Sculpting the microbiome: how host factors determine and respond to microbial colonization'.

Helper T cell immunity in humans with inherited CD4 deficiency

CD4+ T cells are vital for host defense and immune regulation. However, the fundamental role of CD4 itself remains enigmatic. We report seven patients aged 5-61 years from five families of four ancestries with autosomal recessive CD4 deficiency and a range of infections, including recalcitrant warts and Whipple's disease. All patients are homozygous for rare deleterious CD4 variants impacting expression of the canonical CD4 isoform. A shorter expressed isoform that interacts with LCK, but not HLA class II, is affected by only one variant. All patients lack CD4+ T cells and have increased numbers of TCRαβ+CD4-CD8- T cells, which phenotypically and transcriptionally resemble conventional Th cells. Finally, patient CD4-CD8- αβ T cells exhibit intact responses to HLA class II-restricted antigens and promote B cell differentiation in vitro. Thus, compensatory development of Th cells enables patients with inherited CD4 deficiency to acquire effective cellular and humoral immunity against an unexpectedly large range of pathogens. Nevertheless, CD4 is indispensable for protective immunity against at least human papillomaviruses and Trophyrema whipplei.

Induction of immortal-like and functional CAR T cells by defined factors

Long-term antitumor efficacy of chimeric antigen receptor (CAR) T cells depends on their functional persistence in vivo. T cells with stem-like properties show better persistence, but factors conferring bona fide stemness to T cells remain to be determined. Here, we demonstrate the induction of CAR T cells into an immortal-like and functional state, termed TIF. The induction of CARTIF cells depends on the repression of two factors, BCOR and ZC3H12A, and requires antigen or CAR tonic signaling. Reprogrammed CARTIF cells possess almost infinite stemness, similar to induced pluripotent stem cells while retaining the functionality of mature T cells, resulting in superior antitumor effects. Following the elimination of target cells, CARTIF cells enter a metabolically dormant state, persisting in vivo with a saturable niche and providing memory protection. TIF represents a novel state of T cells with unprecedented stemness, which confers long-term functional persistence of CAR T cells in vivo and holds broad potential in T cell therapies.

Cereal weevils' antimicrobial peptides: at the crosstalk between development, endosymbiosis and immune response

Interactions between animals and microbes are ubiquitous in nature and strongly impact animal physiology. These interactions are shaped by the host immune system, which responds to infections and contributes to tailor the associations with beneficial microorganisms. In many insects, beneficial symbiotic associations not only include gut commensals, but also intracellular bacteria, or endosymbionts. Endosymbionts are housed within specialized host cells, the bacteriocytes, and are transmitted vertically across host generations. Host-endosymbiont co-evolution shapes the endosymbiont genome and host immune system, which not only fights against microbial intruders, but also ensures the preservation of endosymbionts and the control of their load and location. The cereal weevil Sitophilus spp. is a remarkable model in which to study the evolutionary adaptation of the immune system to endosymbiosis owing to its binary association with a unique, relatively recently acquired nutritional endosymbiont, Sodalis pierantonius. This Gram-negative bacterium has not experienced the genome size shrinkage observed in long-term endosymbioses and has retained immunogenicity. We focus here on the sixteen antimicrobial peptides (AMPs) identified in the Sitophilus oryzae genome and their expression patterns in different tissues, along host development or upon immune challenges, to address their potential functions in the defensive response and endosymbiosis homeostasis along the insect life cycle. This article is part of the theme issue 'Sculpting the microbiome: how host factors determine and respond to microbial colonization'.

Evolutionary immunology to explore original antiviral strategies

Over the past 25 years, the field of evolutionary developmental biology (evo-devo) has used genomics and genetics to gain insight on the developmental mechanisms underlying the evolution of morphological diversity of animals. Evo-devo exploits the key insight that conserved toolkits of development (e.g. Hox genes) are used in animals to produce genetic novelties that provide adaptation to a new environment. Like development, immunity is forged by interactions with the environment, namely the microbial world. Yet, when it comes to the study of immune defence mechanisms in invertebrates, interest primarily focuses on evolutionarily conserved molecules also present in humans. Here, focusing on antiviral immunity, we argue that immune genes not conserved in humans represent an unexplored resource for the discovery of new antiviral strategies. We review recent findings on the cGAS-STING pathway and explain how cyclic dinucleotides produced by cGAS-like receptors may be used to investigate the portfolio of antiviral genes in a broad range of species. This will set the stage for evo-immuno approaches, exploiting the investment in antiviral defences made by metazoans over hundreds of millions of years of evolution. This article is part of the theme issue 'Sculpting the microbiome: how host factors determine and respond to microbial colonization'.

Human neutrophils drive skin autoinflammation by releasing interleukin (IL)-26

Autoinflammation is a sterile inflammatory process resulting from increased neutrophil infiltration and overexpression of IL-1 cytokines. The factors that trigger these events are, however, poorly understood. By investigating pustular forms of psoriasis, we show that human neutrophils constitutively express IL-26 and abundantly release it from granular stores upon activation. In pustular psoriasis, neutrophil-derived IL-26 drives the pathogenic autoinflammation process by inducing the expression of IL-1 cytokines and chemokines that further recruit neutrophils. This occurs via activation of IL-26R in keratinocytes and via the formation of complexes between IL-26 and microbiota DNA, which trigger TLR9 activation of neutrophils. Thus our findings identify neutrophils as an important source of IL-26 and point to IL-26 as the key link between neutrophils and a self-sustaining autoinflammation loop in pustular psoriasis.

Cross-talk and mutual shaping between the immune system and the microbiota during an oyster's life

The Pacific oyster Crassostrea gigas lives in microbe-rich marine coastal systems subjected to rapid environmental changes. It harbours a diversified and fluctuating microbiota that cohabits with immune cells expressing a diversified immune gene repertoire. In the early stages of oyster development, just after fertilization, the microbiota plays a key role in educating the immune system. Exposure to a rich microbial environment at the larval stage leads to an increase in immune competence throughout the life of the oyster, conferring a better protection against pathogenic infections at later juvenile/adult stages. This beneficial effect, which is intergenerational, is associated with epigenetic remodelling. At juvenile stages, the educated immune system participates in the control of the homeostasis. In particular, the microbiota is fine-tuned by oyster antimicrobial peptides acting through specific and synergistic effects. However, this balance is fragile, as illustrated by the Pacific Oyster Mortality Syndrome, a disease causing mass mortalities in oysters worldwide. In this disease, the weakening of oyster immune defences by OsHV-1 µVar virus induces a dysbiosis leading to fatal sepsis. This review illustrates the continuous interaction between the highly diversified oyster immune system and its dynamic microbiota throughout its life, and the importance of this cross-talk for oyster health. This article is part of the theme issue 'Sculpting the microbiome: how host factors determine and respond to microbial colonization'.

Role of sulfatide-reactive vNKT cells in promoting lung Treg cells via dendritic cell modulation in asthma models

Our previous studies have showed that sulfatide-reactive type II NKT (i.e. variant NKT, vNKT) cells inhibit the immunogenic maturation during the development of mature lung dendritic cells (LDCs), leading todeclined allergic airway inflammation in asthma. Nonetheless, the specific immunoregulatory roles of vNKT cells in LDC-mediated Th2 cell responses remain incompletely understood. Herein, we found that administration of sulfatide facilitated the generation of CD4+FoxP3+ regulatory T (Treg) cells in the lungs of wild-type mice, but not in CD1d-/- and Jα18-/- mice, after ovalbumin or house dust mite exposure. This finding implies that the enhancement of lung Treg cells by sulfatide requires vNKT cells, which dependent on invariant NKT (iNKT) cells. Furthermore, the CD4+FoxP3+ Treg cells induced by sulfatide-reactive vNKT cells were found to be associated with PD-L1 molecules expressed on LDCs, and this association was dependent on iNKT cells. Collectively, our findings suggest that in asthma-mimicking murine models, sulfatide-reactive vNKT cells facilitate the generation of lung Treg cells through inducing tolerogenic properties in LDCs, and this process is dependent on the presence of lung iNKT cells. These results may provide a potential therapeutic approach to treat allergic asthma.

Angiotoxic effects of chlorinated polyfluorinated ether sulfonate, a novel perfluorooctane sulfonate substitute, in vivo and in vitro

Chlorinated polyfluorinated ether sulfonate (Cl-PFESA), a substitute for perfluorooctane sulfonate (PFOS), has been widely used in the Chinese electroplating industry under the trade name F-53B. The production and use of F-53B is keep increasing in recent years, consequently causing more emissions into the environment. Thus, there is a growing concern about the adverse effects of F-53B on human health. However, related research is very limited, particularly in terms of its toxicity to the vascular system. In this study, C57BL/6 J mice were exposed to 0.04, 0.2, and 1 mg/kg F-53B for 12 weeks to assess its impact on the vascular system. We found that F-53B exposure caused aortic wall thickening, collagen deposition, and reduced elasticity in mice. In addition, F-53B exposure led to a loss of vascular endothelial integrity and a vascular inflammatory response. Intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were found to be indispensable for this process. Furthermore, RNA sequencing analysis revealed that F-53B can decrease the repair capacity of endothelial cells by inhibiting their proliferation and migration. Collectively, our findings demonstrate that F-53B exposure induces vascular inflammation and loss of endothelial integrity as well as suppresses the repair capacity of endothelial cells, which ultimately results in vascular injury, highlighting the need for a more thorough risk assessment of F-53B to human health.

Targeting oncogenic kinases: Insights on FDA approved tyrosine kinase inhibitors

Protein kinases play pivotal roles in various biological functions, influencing cell differentiation, promoting survival, and regulating the cell cycle. The disruption of protein kinase activity is intricately linked to pathways in tumor development. This manuscript explores the transformative impact of protein kinase inhibitors on cancer therapy, particularly their efficacy in cases driven by targeted mutations. Focusing on key tyrosine kinase inhibitors (TKIs) like Bcr-Abl, Epidermal Growth Factor Receptor (EGFR), and Vascular Endothelial Growth Factor Receptor (VEGFR), it targets critical kinase families in cancer progression. Clinical trial details of these TKIs offer insights into their therapeutic potentials. Learning from FDA-approved kinase inhibitors, the review dissects trends in kinase drug development since imatinib's paradigm-shifting approval in 2001. TKIs have evolved into pivotal drugs, extending beyond oncology. Ongoing clinical trials explore novel kinase targets, revealing the vast potential within the human kinome. The manuscript provides a detailed analysis of advancements until 2022, discussing the roles of specific oncogenic protein kinases in cancer development and carcinogenesis. Our exploration on PubMed for relevant and significant TKIs undergoing pre-FDA approval phase III clinical trials enriches the discussion with valuable findings. While kinase inhibitors exhibit lower toxicity than traditional chemotherapy in cancer treatment, challenges like resistance and side effects emphasize the necessity of understanding resistance mechanisms, prompting the development of novel inhibitors like osimertinib targeting specific mutant proteins. The review advocates thorough research on effective combination therapies, highlighting the future development of more selective RTKIs to optimize patient-specific cancer treatment and reduce adverse events.

JAK2/STAT3 as a new potential target to manage neurodegenerative diseases: An interactive review

Neurodegenerative diseases (NDDs) are a collection of incapacitating disorders in which neuroinflammation and neuronal apoptosis are major pathological consequences due to oxidative stress. Neuroinflammation manifests in the impacted cerebral areas as a result of pro-inflammatory cytokines stimulating the Janus Kinase2 (JAK2)/Signal Transducers and Activators of Transcription3 (STAT3) pathway via neuronal cells. The pro-inflammatory cytokines bind to their respective receptor in the neuronal cells and allow activation of JAK2. Activated JAK2 phosphorylates tyrosines on the intracellular domains of the receptor which recruit the STAT3 transcription factor. The neuroinflammation issues are exacerbated by the active JAK2/STAT3 signaling pathway in conjunction with additional transcription factors like nuclear factor kappa B (NF-κB), and the mammalian target of rapamycin (mTOR). Neuronal apoptosis is a natural process made worse by persistent neuroinflammation and immunological responses via caspase-3 activation. The dysregulation of micro-RNA (miR) expression has been observed in the consequences of neuroinflammation and neuronal apoptosis. Neuroinflammation and neuronal apoptosis-associated gene amplification may be caused by dysregulated miR-mediated aberrant phosphorylation of JAK2/STAT3 signaling pathway components. Therefore, JAK2/STAT3 is an attractive therapeutic target for NDDs. Numerous synthetic and natural small molecules as JAK2/STAT3 inhibitors have therapeutic advances against a wide range of diseases, and many are now in human clinical studies. This review explored the interactive role of the JAK2/STAT3 signaling system with key pathological factors during the reinforcement of NDDs. Also, the clinical trial data provides reasoning evidence about the possible use of JAK2/STAT3 inhibitors to abate neuroinflammation and neuronal apoptosis in NDDs.

Naringenin reduces oxidative stress and necroptosis, apoptosis, and pyroptosis in random-pattern skin flaps by enhancing autophagy

BACKGROUND

Random skin flap grafting is one of the most commonly used techniques in plastic and orthopedic surgery. However, necrosis resulting from ischemia and ischemia-reperfusion injury in the distal part of the flap can severely limit the clinical application of the flap. Studies have revealed that naringenin reduces pyroptosis, apoptosis, and necroptosis, inhibits oxidative stress, and promotes autophagy. In this study, the effects of Naringenin on flap viability and its underlying mechanism were evaluated.

METHODS

Mice with random skin flaps were randomly allocated to control, Naringenin, and Naringenin + 3-methyladenine groups. On postoperative day 7, flap tissues were collected to estimate angiogenesis, necroptosis, apoptosis, pyroptosis, oxidative stress, and autophagy via hematoxylin and eosin staining, immunofluorescence, and immunohistochemistry.

RESULTS

The results revealed that naringenin promoted the viability of the random flaps as well as angiogenesis, while inhibiting oxidative stress and decreasing pyroptosis, apoptosis, and necroptosis. These effects were reversed by the autophagy inhibitor 3-methyladenine.

CONCLUSIONS

The findings indicated that naringenin treatment could promote flap survival by inhibiting pyroptosis, apoptosis, necroptosis, and alleviating oxidative stress, caused by the activation of autophagy.

Complement inhibitors in pediatric kidney diseases: new therapeutic opportunities

Historically, the complement system (classical, lectin, alternative, and terminal pathways) is known to play a crucial role in the etiopathogenesis of many kidney diseases. Direct or indirect activation in these settings is revealed by consumption of complement proteins at the serum level and kidney tissue deposition seen by immunofluorescence and electron microscopy. The advent of eculizumab has shown that complement inhibitors may improve the natural history of certain kidney diseases. Since then, the number of available therapeutic molecules and experimental studies on complement inhibition has increased exponentially. In our narrative review, we give a summary of the main complement inhibitors that have completed phase II and phase III studies or are currently used in adult and pediatric nephrology. The relevant full-text works, abstracts, and ongoing trials (clinicaltrials.gov site) are discussed. Data and key clinical features are reported for eculizumab, ravulizumab, crovalimab, avacopan, danicopan, iptacopan, pegcetacoplan, and narsoplimab. Many of these molecules have been shown to be effective in reducing proteinuria and stabilizing kidney function in different complement-mediated kidney diseases. Thanks to their efficacy and target specificity, these novel drugs may radically improve the outcome of complement-mediated kidney diseases, contributing to an improvement in our understanding of their underlying pathophysiology.

Enhanced innate responses in microglia derived from retinoblastoma patient-specific iPSCs

RB1 deficiency leads to retinoblastoma (Rb), the most prevalent intraocular malignancy. Tumor-associated macrophages (TAMs) are related to local inflammation disorder, particularly by increasing cytokines and immune escape. Microglia, the unique resident macrophages for retinal homeostasis, are the most important immune cells of Rb. However, whether RB1 deficiency affects microglial function remain unknown. In this study, microglia were successfully differentiated from Rb patient- derived human induced pluripotent stem cells (hiPSCs) and human embryonic stem cells (hESCs), and then we investigated the function of RB1 in microglia by live imaging phagocytosis assay, immunofluorescence, RNA-seq, qRT-PCR, ELISA and retina organoids/microglia co-culturing. RB1 was abundantly expressed in microglia and predominantly located in the nucleus. We then examined the phagocytosis ability and secretion function of iMGs in vitro. We found that RB1 deficiency did not affect the expression of microglia-specific markers or the phagocytic abilities of these cells by live-imaging. Upon LPS stimulation, RB1-deficient microglia displayed enhanced innate immune responses, as evidenced by activated MAPK signaling pathway and elevated expression of IL-6 and TNF-α at both mRNA and protein levels, compared to wildtype microglia. Furthermore, retinal structure disruption was observed when retinal organoids were co-cultured with RB1-deficient microglia, highlighting the potential contribution of microglia to Rb development and potential therapeutic strategies for retinoblastoma.

Bioinformatics characteristics and expression analysis of IL-8 and IL-10 in largemouth bass (Micropterus salmoides) upon Nocardia seriolae infection

IL-8 and IL-10 are crucial inflammatory cytokines that participate in defending host cells against infections. To demonstrate the function of the two interleukin genes in largemouth bass (Micropterus salmoides), we initially cloned and identified the cDNA sequences of il-8 and il-10 in largemouth bass, referred to as Msil-8 and Msil-10, respectively. The open reading frame (ORF) of Msil-8 was 324 bp in length, encoding 107 amino acids, while the ORF of Msil-10 consisted of 726 bp and encoded 241 amino acids. Furthermore, the functional domains of the SCY domain in MsIL-8 and the IL-10 family signature motif in MsIL-10 were highly conserved across vertebrates. Additionally, both MsIL-8 and MsIL-10 showed close relationships with M. dolomieu. Constitutive expression of Msil-8 and Msil-10 was observed in various tissues, with the highest level found in the head kidney. Subsequently, largemouth bass were infected with Nocardia seriolae via intraperitoneal injection to gain a further understanding of the function of these two genes. Bacterial loads were initially detected in the foregut, followed by the midgut, hindgut, and liver. The mRNA expression of Msil-8 was significantly down-regulated after infection, especially at 2 days post-infection (DPI), with a similar expression to Msil-10. In contrast, the expression of Msil-8 and Msil-10 was significantly upregulated in the foregut at 14 DPI. Taken together, these results reveal that the function of IL-8 and IL-10 was likely hindered by N. seriolae, which promoted bacterial proliferation and intercellular diffusion.

Bulk and single cells transcriptomes with experimental validation identify USP18 as a novel glioma prognosis and proliferation indicator

The mechanism by which ubiquitin-specific protease 18 (USP18) (enzyme commission: 3.4.19.12) inhibition in cancer promotes cell pyroptosis via the induction of interferon (IFN)-stimulated genes has been recently demonstrated. It is also known that USP18 influences the epithelial-mesenchymal transition of glioma cells. In the present study, the upregulation of USP18 in glioma was revealed through bulk transcriptome analysis, which was associated with poor prognosis in patients with glioma. Furthermore, USP18 levels affected the response to immunotherapy in patients with glioma. Single-cell transcriptome and enrichment analyses demonstrated that USP18 was associated with type 1 IFN responses in glioma T cells. To demonstrate the effect of USP18 expression levels on glioma cells, USP18 expression was knocked down in U251 and U87MG ATCC cell lines. A subsequent Cell Counting Kit-8 assay revealed that glioma cell viability was significantly decreased 4 days after USP18 knockdown. In addition, the knockdown of USP18 expression significantly inhibited the clonogenicity of U251 and U87MG ATCC cells. In conclusion, the present study demonstrated that knockdown of USP18 expression inhibited the proliferation of glioma cells, which may be mediated by the effect of USP18 on the IFN-I response.

Targeting terminal pathway reduces brain complement activation, amyloid load and synapse loss, and improves cognition in a mouse model of dementia

Complement is dysregulated in the brain in Alzheimer's Disease and in mouse models of Alzheimer's disease. Each of the complement derived effectors, opsonins, anaphylatoxins and membrane attack complex (MAC), have been implicated as drivers of disease but their relative contributions remain unclarified. Here we have focussed on the MAC, a lytic and pro-inflammatory effector, in the AppNL-G-F mouse amyloidopathy model. To test the role of MAC, we back-crossed to generate AppNL-G-F mice deficient in C7, an essential MAC component. C7 deficiency ablated MAC formation, reduced synapse loss and amyloid load and improved cognition compared to complement-sufficient AppNL-G-F mice at 8-10 months age. Adding back C7 caused increased MAC formation in brain and an acute loss of synapses in C7-deficient AppNL-G-F mice. To explore whether C7 was a viable therapeutic target, a C7-blocking monoclonal antibody was administered systemically for one month in AppNL-G-F mice aged 8-9 months. Treatment reduced brain MAC and amyloid deposition, increased synapse density and improved cognitive performance compared to isotype control-treated AppNL-G-F mice. The findings implicate MAC as a driver of pathology and highlight the potential for complement inhibition at the level of MAC as a therapy in Alzheimer's disease.

Transcription factors in chimeric antigen receptor T-cell development

Chimeric antigen receptor (CAR) T-cell therapy is a new and innovative approach to treating cancers that has shown promising results in the treatment of lymphoma. However, it has been found to be less effective in the treatment of solid tumors. To overcome the limitation, researchers have explored the use of combined CAR-T therapy with other complementary regimens that target specific genes or biomarkers, which would enhance the synergistic therapeutic effects. Transcription factors (TFs) have been identified as potential markers that can regulate gene expression in CAR-T cells to enhance their cytotoxicity and safety. TFs are known to bind DNA specifically and recruit cofactor proteins to regulate the expression of target genes. By targeting TFs, it is possible to improve the anti-tumor response of CAR-T cells by altering their phenotype and transcriptional map, thereby increasing their effector function, such as reducing the exhaustion, enhancing the survival, and cytotoxicity of CAR-T cells. This review summarizes the application of transcription factors in CART therapy to enhance the synergistic therapeutic effect of CAR-T cells in the treatment of solid tumors and improve their anti-tumor responses.

Immune profiling analysis of double-negative T cells in patients with systemic sclerosis

OBJECTIVE

To construct a molecular immune map of patients with systemic sclerosis (SSc) by mass flow cytometry, and compare the number and molecular expression of double-negative T (DNT) cell subsets between patients and healthy controls (HC).

METHODS

Peripheral blood mononuclear cells (PBMCs) were extracted from the peripheral blood of 17 SSc patients and 9 HC. A 42-channel panel was set up to perform mass cytometry by time of flight (CyTOF) analysis for DNT subgroups. Flow cytometry was used to validate subpopulation functions. The clinical data of patients were collected for correlation analysis.

RESULTS

Compared with HC, the number of total DNT cells decreased in SSc patients. Six DNT subsets were obtained from CyTOF analysis, in which the proportion of cluster1 increased, while the proportion of cluster3 decreased. Further analysis revealed that cluster1 was characterized by high expression of CD28 and CCR7, and cluster3 was characterized by high expression of CD28 and CCR5. After in vitro stimulation, cluster1 secreted more IL-4 and cluster3 secreted more IL-10 in SSc patients compared to HC. Clinical correlation analysis suggested that cluster1 may play a pathogenic role while cluster3 may play a protective role in SSc. ROC curve analysis further revealed that cluster3 may be a potential indicator for determining disease activity in SSc patients.

CONCLUSION

We found a new CCR5+CD28+ DNT cell subset, which played a protective role in the pathogenesis of SSc. Key Points • The number of DNT cells decreased in SSc patients' peripheral blood. • DNT cells do not infiltrate in the skin but secrete cytokines to participate in the pathogenesis of SSc. • A CCR5+CD28+ DNT cell population may play a protective role in SSc.

Microenvironmental changes in familial adenomatous polyposis during colorectal cancer carcinogenesis

Familial adenomatous polyposis (FAP) is a heritable disease that increases the risk of colorectal cancer (CRC) development because of heterozygous mutations in APC. Little is known about the microenvironment of FAP. Here, single-cell RNA sequencing was performed on matched normal tissues, adenomas, and carcinomas from four patients with FAP. We analyzed the transcriptomes of 56,225 unsorted single cells, revealing the heterogeneity of each cell type, and compared gene expression among tissues. Then we compared the gene expression with that of sporadic CRC. Furthermore, we analyzed specimens of 26 FAP patients and 40 sporadic CRC patients by immunohistochemistry. Immunosuppressiveness of myeloid cells, fibroblasts, and regulatory T cells was upregulated even in the early stages of carcinogenesis. CD8+ T cells became exhausted only in carcinoma, although the cytotoxicity of CD8+ T cells was gradually increased according to the carcinogenic step. When compared with those in the sporadic CRC microenvironment, the composition and function of each cell type in the FAP-derived CRC microenvironment had differences. Our findings indicate that an immunosuppressive microenvironment is constructed from a precancerous stage in FAP.

Viral infection transmission and indoor air quality: A systematic review

Respiratory disease transmission in indoor environments presents persistent challenges for health authorities, as exemplified by the recent COVID-19 pandemic. This underscores the urgent necessity to investigate the dynamics of viral infection transmission within indoor environments. This systematic review delves into the methodologies of respiratory infection transmission in indoor settings and explores how the quality of indoor air (IAQ) can be controlled to alleviate this risk while considering the imperative of sustainability. Among the 2722 articles reviewed, 178 were retained based on their focus on respiratory viral infection transmission and IAQ. Fifty eight articles delved into SARS-CoV-2 transmission, 21 papers evaluated IAQ in contexts of other pandemics, 53 papers assessed IAQ during the SARS-CoV-2 pandemic, and 46 papers examined control strategies to mitigate infectious transmission. Furthermore, of the 46 papers investigating control strategies, only nine considered energy consumption. These findings highlight clear gaps in current research, such as analyzing indoor air and surface samples for specific indoor environments, oversight of indoor and outdoor parameters (e.g., temperature, relative humidity (RH), and building orientation), neglect of occupancy schedules, and the absence of considerations for energy consumption while enhancing IAQ. This study distinctly identifies the indoor environmental conditions conducive to the thriving of each respiratory virus, offering IAQ trade-offs to mitigate the risk of dominant viruses at any given time. This study argues that future research should involve digital twins in conjunction with machine learning (ML) techniques. This approach aims to enhance IAQ by analyzing the transmission patterns of various respiratory viruses while considering energy consumption.

Adoptive cellular therapy after hematopoietic stem cell transplantation

Effective cellular therapy using CD19 chimeric antigen receptor T-cells for the treatment of advanced B-cell malignancies raises the question of whether the administration of adoptive cellular therapy (ACT) posttransplant could reduce relapse and improve survival. Moreover, several early phase clinical studies have shown the potential beneficial effects of administration of tumor-associated antigen-specific T-cells and natural killer cells posttransplant for high-risk patients, aiming to decrease relapse and possibly improve survival. In this article, we present an in-depth review of ACT after transplantation, which has the potential to significantly improve the efficacy of this procedure and revolutionize this field.

Circulating cytokines and vascular dementia: A bi-directional Mendelian randomization study

Inflammatory responses are associated with the development of vascular dementia (VaD). Circulating cytokines modulate the inflammatory response and are important for the immune system. To further elucidate the role of the immune system in VaD, we used Mendelian randomization (MR) to comprehensively and bi-directionally assess the role of circulating cytokines in VaD. Using state-of-the-art genome-wide association studies, we primarily assessed whether different genetic levels of 41 circulating cytokines affect the risk of developing VaD and, in turn, whether the genetic risk of VaD affects these circulating cytokines. We used inverse variance weighting (IVW) and several other MR methods to assess the bidirectional causality between circulating cytokines and VaD, and performed sensitivity analyses. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) was inversely associated with VaD risk [odds ratio (OR): 0.74, 95 % confidence interval (CI): 0.60-0.92, P = 0.007, 0.007]. VaD was associated with seven circulating cytokines: macrophage inflammatory protein 1b (MIP-1 beta) [OR: 1.05, 95 % CI: 1.01-1.08, P = 0.009], Interleukin-12p70 (IL-12) [OR: 1.04, 95 % CI: 1.00-1.08, P = 0.047], Interleukin-17 (IL-17) [OR: 1.04, 95 % CI: 1.00-1.07, P = 0.038], Interleukin-7 (IL-7) [OR: 1.07, 95 % CI: 1.02-1.12, P = 0.009], Interferon gamma (IFN-γ) [OR: 1.03, 95 % CI: 1.00-1.07, P = 0.046], Granulocyte-colony stimulating factor (GCSF) [OR: 1.06, 95 % CI: 1.02-1.09, P = 0.001], Fibroblast growth factor (FGF) [P = 0.001], and Fibroblast growth factor (FGF) [P = 0.001]. Fibroblast growth factor basic (FGF-Basic) [OR: 1.04, 95 % CI: 1.01-1.08, P = 0.02] were positively correlated. Circulating cytokines are associated with VaD, and further studies are needed to determine whether they are effective targets for intervention to prevent or treat VaD.

A comprehensive review on the role of mesenchymal stromal/stem cells in the management of rheumatoid arthritis

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease with systemic manifestations. Although the success of immune modulatory drug therapy is considerable, about 40% of patients do not respond to treatment. Mesenchymal stromal/stem cells (MSCs) have been demonstrated to have therapeutic potential for inflammatory diseases.

AREAS COVERED

This review provides an update on RA disease and on pre-clinical and clinical studies using MSCs from bone marrow, umbilical cord, adipose tissue, and dental pulp, to regulate the immune response. Moreover, the clinical use, safety, limitations, and future perspective of MSCs in RA are discussed. Using the PubMed database and ClincalTrials.gov, peer-reviewed full-text papers, abstracts and clinical trials were identified from 1985 through to April 2023.

EXPERT OPINION

MSCs demonstrated a satisfactory safety profile and potential for clinical efficacy. However, it is mandatory to deepen the investigations on how MSCs affect the proinflammatory deregulated RA patients' cells. MSCs are potentially good candidates for severe RA patients not responding to conventional therapies but a long-term follow-up after stem cells treatment and standardized protocols are needed. Future research should focus on well-designed multicenter randomized clinical trials with adequate sample sizes and properly selected patients satisfying RA criteria for a valid efficacy evaluation.

Unlocking PD-1 antibody resistance: The MUC1 DNA vaccine augments CD8+ T cell infiltration and attenuates tumour suppression

In light of increasing resistance to PD1 antibody therapy among certain patient populations, there is a critical need for in-depth research. Our study assesses the synergistic effects of a MUC1 DNA vaccine and PD1 antibody for surmounting PD1 resistance, employing a murine CT26/MUC1 colon carcinoma model for this purpose. When given as a standalone treatment, PD1 antibodies showed no impact on tumour growth. Additionally, there was no change observed in the intra-tumoural T-cell ratios or in the functionality of T-cells. In contrast, the sole administration of a MUC1 DNA vaccine markedly boosted the cytotoxicity of CD8+ T cells by elevating IFN-γ and granzyme B production. Our compelling evidence highlights that combination therapy more effectively inhibited tumour growth and prolonged survival compared to either monotherapy, thus mitigating the limitations intrinsic to single-agent therapies. This enhanced efficacy was driven by a significant alteration in the tumour microenvironment, skewing it towards pro-immunogenic conditions. This assertion is backed by a raised CD8+/CD4+ T-cell ratio and a decrease in immunosuppressive MDSC and Treg cell populations. On the mechanistic front, the synergistic therapy amplified expression levels of CXCL13 in tumours, subsequently facilitating T-cell ingress into the tumour setting. In summary, our findings advocate for integrated therapy as a potent mechanism for surmounting PD1 antibody resistance, capitalizing on improved T-cell functionality and infiltration. This investigation affords critical perspectives on enhancing anti-tumour immunity through the application of innovative therapeutic strategies.

An optimized non-T cell transfection system based on HEK293FT cells for CD3ζ phosphorylation and ubiquitination

CD3ζ is part of the T cell receptor (TCR)/CD3 complex that plays a critical role in antigen recognition and subsequent T cell activation. Understanding the mechanisms that regulate CD3ζ can provide new insights into the T cell-mediated immune responses. However, it is challenging to deliver exogenous genes into T cells for functional and mechanistic analyses. To this end, we established a non-T cell transfection system based on HEK293FT cells to screen for candidate regulatory proteins. The transfection was optimized using relatively high confluent cultures and the transfection reagent PolyJet™. Pervanadate (PV) treatment sustained tyrosine phosphorylation of CD3ζ, and facilitated the subsequent activation-dependent ubiquitination by E3 ligase Cbl-b in the HEK293FT system. Lck and Zap70 kinases enhanced the levels of phosphorylated CD3ζ in the presence of PV. We compared the effects of E3 ligases and the corresponding adaptor proteins on activation-dependent ubiquitination of CD3ζ in the PV-stimulated cells, and found that Cbl-b was most effective. Taken together, we have demonstrated that a non-T cell transfection system based on PV-treated HEK293FT cells could effectively mimic CD3ζ phosphorylation and ubiquitination and is a promising model for studying the role of CD3ζ signaling in T cell activation.

The interaction between the costimulatory molecules CD80/86 and CD28 contributed to CD4+ T lymphocyte activation in flounder (Paralichthys olivaceus)

CD28 and CD80/86 are crucial co-stimulatory molecules for the T cell activation. Previous study illustrated that CD28 and CD80/86 present on T cells and antigen-presenting cells in flounder (Paralichthys olivaceus), respectively. The co-stimulatory molecules were closely associated with cell immunity. In this paper, recombinant protein of flounder CD80/86 (rCD80/86) and phytohemagglutinin (PHA) were added to peripheral blood leukocytes (PBLs) in vitro. Lymphocytes were significantly proliferated with CFSE staining, and the proportion of CD4+ and CD28+ lymphocytes significantly increased. In the meantime, genes related to the CD28-CD80/86 signaling pathway or T cell markers were significantly upregulated (p < 0.05). For further study, the interaction between CD80/86 and CD28 was confirmed. The plasmid of CD28 (pCD28-FLAG and pVN-CD28) or CD80/86 (pVC-CD80/86) was successfully constructed. In addition, pVN-ΔCD28 without the conserved motif "TFPPPF" was constructed. The results showed that bands of pCD28-FLAG bound to rCD80/86 were detected by both anti-FLAG and anti-CD80/86. pVN-CD28 complemented to pVC-CD80/86 showing positive fluorescent signals, and pVN-ΔCD28 failed to combine with pVC-CD80/86. The motif "TFPPPF" in CD28 played a crucial role in this linkage. These results indicate that CD28 and CD80/86 molecules interact with each other, and their binding may modulate T lymphocytes immune response in flounder. This study proved the existence of CD28-CD80/86 signaling pathway in flounder.

Novel therapeutic strategies targeting abnormal T-cell signaling in systemic lupus erythematosus

Therapeutic strategies for autoimmune diseases have been based on the use of glucocorticoids and immunosuppressive agents that broadly suppress immune responses. Therefore, organ damage from long-term use and infections due to immunocompromised status have been significant issues. Safer immunosuppressants and biological agents are now available, but there is still an urgent need to develop specific drugs to replace glucocorticoids. T-lymphocytes, central players in immune responses, could be crucial targets in the treatment of autoimmune diseases. Extensive research has been conducted on the phenotypic changes of T-cells in systemic lupus erythematosus, which has led to the discovery of various therapeutic strategies. In this comprehensive review, we discuss novel treatment approaches and target molecules with expected effectiveness in humans and mice, based on research for lymphocytes involved in autoimmune diseases, especially T-cells in SLE.

Prognostic biomarker HIF1α and its correlation with immune infiltration in gliomas

Certain glioma subtypes, such as glioblastoma multiforme or low-grade glioma, are common malignant intracranial tumors with high rates of relapse and malignant progression even after standard therapy. The overall survival (OS) is poor in patients with gliomas; hence, effective prognostic prediction is crucial. Herein, the present study aimed to explore the potential role of hypoxia-inducible factor 1 subunit alpha (HIF1α) in gliomas and investigate the association between HIF1α and infiltrating immune cells in gliomas. Data from The Cancer Genome Atlas were evaluated via RNA sequencing, clinicopathological, immunological checkpoint, immune infiltration and functional enrichment analyses. Validation of protein abundance was performed using paraffin-embedded samples from patients with glioma. A nomogram model was created to forecast the OS rates at 1, 3 and 5 years after cancer diagnosis. The association between OS and HIF1α expression was estimated using Kaplan-Meier survival analysis and the log-rank test. Finally, HIF1α expression was validated using western blotting, reverse transcription-quantitative PCR, Cell Counting Kit-8 and Transwell assays. The results demonstrated that HIF1α expression was significantly upregulated in gliomas compared with normal human brain glial cells. Immunohistochemistry staining demonstrated differential expression of the HIF1α protein. Moreover, glioma cell viability and migration were inhibited via HIF1α downregulation. HIF1α impacted DNA replication, cell cycling, DNA repair and the immune microenvironment in glioma. HIF1α expression was also positively associated with several types of immune cells and immunological checkpoints and with neutrophils, plasmacytoid dendritic cells and CD56bright cells. The Kaplan-Meier survival analyses further demonstrated a strong association between high HIF1α expression and poor prognosis in patients with glioma. Analysis of the receiver operating characteristic curves demonstrated that HIF1α expression accurately differentiated paired normal brain cells from tumor tissues. Collectively, these findings suggested the potential for HIF1α to be used as a novel prognostic indicator for patients with glioma and that OS prediction models may help in the future to develop effective follow-up and treatment strategies for these patients.

Microglia-neuron-vascular interactions in ischemia

Cerebral ischemia is a devastating condition that results in impaired blood flow in the brain leading to acute brain injury. As the most common form of stroke, occlusion of cerebral arteries leads to a characteristic sequence of pathophysiological changes in the brain tissue. The mechanisms involved, and comorbidities that determine outcome after an ischemic event appear to be highly heterogeneous. On their own, the processes leading to neuronal injury in the absence of sufficient blood supply to meet the metabolic demand of the cells are complex and manifest at different temporal and spatial scales. While the contribution of non-neuronal cells to stroke pathophysiology is increasingly recognized, recent data show that microglia, the main immune cells of the central nervous system parenchyma, play previously unrecognized roles in basic physiological processes beyond their inflammatory functions, which markedly change during ischemic conditions. In this review, we aim to discuss some of the known microglia-neuron-vascular interactions assumed to contribute to the acute and delayed pathologies after cerebral ischemia. Because the mechanisms of neuronal injury have been extensively discussed in several excellent previous reviews, here we focus on some recently explored pathways that may directly or indirectly shape neuronal injury through microglia-related actions. These discoveries suggest that modulating gliovascular processes in different forms of stroke and other neurological disorders might have presently unexplored therapeutic potential in combination with neuroprotective and flow restoration strategies.

Emerging biologic therapies for systemic lupus erythematosus

PURPOSE OF REVIEW

The approval of belimumab and anifrolumab has expanded the scope of treatment for systemic lupus erythematosus (SLE) patients. However, many patients remain refractory to currently available therapies and suffer from drug toxicities. This review will discuss approved and target-specific therapeutics in development that bring hope for better SLE treatments.

RECENT FINDINGS

Since the last review on this subject in the journal, the FDA has approved anifrolumab and belimumab for SLE and lupus nephritis (LN), respectively. A fully humanized anti-CD20, obinutuzumab, met the primary end point in a phase II trial in LN. A Tyk2 inhibitor, deucravacitinib, and an antibody targeting plasmacytoid dendritic cells, litifilimab, met the primary end point in phase II trials in SLE and cutaneous lupus erythematosus (CLE). Ustekinumab and baricitinib met the primary end point in phase II but not in phase III trials.

SUMMARY

While many drug candidates which met the end points in phase II trials have failed phase III trials, the number of target-specific therapies for SLE has continued to expand.

The dynamics of B-cell reconstitution post allogeneic hematopoietic stem cell transplantation: A real-world study

BACKGROUND

The immune reconstitution after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is crucial for preventing infections and relapse and enhancing graft-versus-tumor effects. B cells play an important role in humoral immunity and immune regulation, but their reconstitution after allo-HSCT has not been well studied.

METHODS

In this study, we analyzed the dynamics of B cells in 252 patients who underwent allo-HSCT for 2 years and assessed the impact of factors on B-cell reconstitution and their correlations with survival outcomes, as well as the development stages of B cells in the bone marrow and the subsets in the peripheral blood.

RESULTS

We found that the B-cell reconstitution in the bone marrow was consistent with the peripheral blood (p = 0.232). B-cell reconstitution was delayed by the male gender, age >50, older donor age, the occurrence of chronic and acute graft-versus-host disease, and the infections of fungi and cytomegalovirus. The survival analysis revealed that patients with lower B cells had higher risks of death and relapse. More importantly, we used propensity score matching to obtain the conclusion that post-1-year B-cell reconstitution is better in females. Meanwhile, using mediation analysis, we proposed the age-B cells-survival axis and found that B-cell reconstitution at month 12 posttransplant mediated the effect of age on patient survival (p = 0.013). We also found that younger patients showed more immature B cells in the bone marrow after transplantation (p = 0.037).

CONCLUSION

Our findings provide valuable insights for optimizing the management of B-cell reconstitution and improving the efficacy and safety of allo-HSCT.

Humanized mice for studying HIV latency and potentially its eradication

PURPOSE OF THE REVIEW

The quest for an HIV cure faces a formidable challenge: the persistent presence of latent viral infections within the cells and tissues of infected individuals. This review provides a thorough examination of discussions surrounding HIV latency, the use of humanized mouse models, and strategies aimed at eliminating the latent HIV reservoir. It explores the hurdles and advancements in understanding HIV pathogenesis, mainly focusing on establishing latent reservoirs in CD4 + T cells and macrophages. Introducing the concepts of functional and sterile cures, the review underscores the indispensable role of humanized mouse models in HIV research, offering crucial insights into the efficacy of cART and the ongoing pursuit of an HIV cure.

RECENT FINDINGS

Here, we highlight studies investigating molecular mechanisms and pathogenesis related to HIV latency in humanized mice and discuss novel strategies for eradicating latent HIV. Emphasizing the importance of analytical cART interruption in humanized mouse studies to gauge its impact on the latent reservoir accurately, the review underlines the ongoing progress and challenges in harnessing humanized mouse models for HIV research.

SUMMARY

This review suggests that humanized mice models provide valuable insights into HIV latency and potential eradication strategies, contributing significantly to the quest for an HIV cure.

Reproducibility of 3D pH-weighted chemical exchange saturation transfer contrast in the healthy cervical spinal cord

Spinal cord ischemia and hypoxia can be caused by compression, injury, and vascular alterations. Measuring ischemia and hypoxia directly in the spinal cord noninvasively remains challenging. Ischemia and hypoxia alter tissue pH, providing a physiologic parameter that may be more directly related to tissue viability. Chemical exchange saturation transfer (CEST) is an MRI contrast mechanism that can be made sensitive to pH. More specifically, amine/amide concentration independent detection (AACID) is a recently developed endogenous CEST contrast that has demonstrated sensitivity to intracellular pH at 9.4 T. The goal of this study was to evaluate the reproducibility of AACID CEST measurements at different levels of the healthy cervical spinal cord at 3.0 T incorporating B1 correction. Using a 3.0 T MRI scanner, two 3D CEST scans (saturation pulse train followed by a 3D snapshot gradient-echo readout) were performed on 12 healthy subjects approximately 10 days apart, with the CEST volume centered at the C4 level for all subjects. Scan-rescan reproducibility was evaluated by examining between and within-subject coefficients of variation (CVs) and absolute AACID value differences. The C4 level of the spinal cord demonstrated the lowest within-subject CVs (4.1%-4.3%), between-subject CVs (5.6%-6.3%), and absolute AACID percent difference (5.8-6.1%). The B1 correction scheme significantly improved reproducibility (adjusted p-value = 0.002) compared with the noncorrected data, suggesting that implementing B1 corrections in the spinal cord is beneficial. It was concluded that pH-weighted AACID measurements, incorporating B1-inhomogeneity correction, were reproducible within subjects along the healthy cervical spinal cord and that optimal image quality was achieved at the center of the 3D CEST volume.

Influence of tumor microenvironment on the different breast cancer subtypes and applied therapies

Despite the significant improvements made in breast cancer therapy during the last decades, this disease still has increasing incidence and mortality rates. Different targets involved in general processes, like cell proliferation and survival, have become alternative therapeutic options for this disease, with some of them already used in clinic, like the CDK4/6 inhibitors for luminal A tumors treatment. Nevertheless, there is a demand for novel therapeutic strategies focused not only on tumor cells, but also on their microenvironment. Tumor microenvironment (TME) is a very complex and dynamic system that, more than surrounding and supporting tumor cells, actively participates in tumor development and progression. During the last decades, it has become clear that the cellular and acellular components of TME differ between the various breast cancer subtypes and shape the differences regarding their severity and prognosis. The pivotal role of the TME in controlling tumor growth and influencing responses to therapy represents a potential source for novel targets and therapeutic strategies. In this review, we present a description of the multiple therapeutic options used for different breast cancer subtypes, as well as the influence that the TME may exert on the development of the disease and on the response to the distinct therapies, which in some cases may explain their failure by the occurrence of relapses and resistance. Furthermore, the ongoing studies focused on the use of TME components for developing potential cancer treatments are described.

The changing landscape of HIV-associated kidney disease

The HIV epidemic has devastated millions of people globally, with approximately 40 million deaths since its start. The availability of antiretroviral therapy (ART) has transformed the prognosis of millions of individuals infected with HIV such that a diagnosis of HIV infection no longer automatically confers death. However, morbidity and mortality remain substantial among people living with HIV. HIV can directly infect the kidney to cause HIV-associated nephropathy (HIVAN) - a disease characterized by podocyte and tubular damage and associated with an increased risk of kidney failure. The reports of HIVAN occurring primarily in those of African ancestry led to the discovery of its association with APOL1 risk alleles. The advent of ART has led to a substantial decrease in the prevalence of HIVAN; however, reports have emerged of an increase in the prevalence of other kidney pathology, such as focal segmental glomerulosclerosis and pathological conditions associated with co-morbidities of ageing, such as hypertension and diabetes mellitus. Early initiation of ART also results in a longer cumulative exposure to medications, increasing the likelihood of nephrotoxicity. A substantial body of literature supports the use of kidney transplantation in people living with HIV, demonstrating significant survival benefits compared with that of people undergoing chronic dialysis, and similar long-term allograft and patient survival compared with that of HIV-negative kidney transplant recipients.

A teenage girl with altered mental status and paraparesis

A teenage girl presented with fever and altered mental status. MRI showed diffuse leptomeningeal enhancement of the brain and spine. She was diagnosed by a positive cerebrospinal fluid (CSF) culture with tuberculous (TB) meningitis and was started on anti-TB medications and corticosteroids. Her mental status improved, but she was noted to have proximal weakness of the lower extremities. In the course of tapering corticosteroids at week 11 of anti-TB therapy, she became acutely confused and febrile. MRI demonstrated interval development of tuberculomas in the brain and a mass lesion in the thoracic spine causing cord compression. Given the clinical picture was suggestive of a paradoxical reaction, the dose of corticosteroids was increased. Infliximab was added when repeat MRI revealed enlargement of the mass lesion in the spine with worsening cord compression. She was successfully tapered off of corticosteroids. Over several months, the patient's motor function recovered fully, and she returned to ambulating without assistance.

Cellular and transcriptomic response to pathogenic and non-pathogenic Vibrio parahaemolyticus strains causing acute hepatopancreatic necrosis disease (AHPND) in Litopenaeus vannamei

The shrimp industry has historically been affected by viral and bacterial diseases. One of the most recent emerging diseases is Acute Hepatopancreatic Necrosis Disease (AHPND), which causes severe mortality. Despite its significance to sanitation and economics, little is known about the molecular response of shrimp to this disease. Here, we present the cellular and transcriptomic responses of Litopenaeus vannamei exposed to two Vibrio parahaemolyticus strains for 98 h, wherein one is non-pathogenic (VpN) and the other causes AHPND (VpP). Exposure to the VpN strain resulted in minor alterations in hepatopancreas morphology, including reductions in the size of R and B cells and detachments of small epithelial cells from 72 h onwards. On the other hand, exposure to the VpP strain is characterized by acute detachment of epithelial cells from the hepatopancreatic tubules and infiltration of hemocytes in the inter-tubular spaces. At the end of exposure, RNA-Seq analysis revealed functional enrichment in biological processes, such as the toll3 receptor signaling pathway, apoptotic processes, and production of molecular mediators involved in the inflammatory response of shrimp exposed to VpN treatment. The biological processes identified in the VpP treatment include superoxide anion metabolism, innate immune response, antimicrobial humoral response, and toll3 receptor signaling pathway. Furthermore, KEGG enrichment analysis revealed metabolic pathways associated with survival, cell adhesion, and reactive oxygen species, among others, for shrimp exposed to VpP. Our study proves the differential immune responses to two strains of V. parahaemolyticus, one pathogenic and the other nonpathogenic, enlarges our knowledge on the evolution of AHPND in L. vannamei, and uncovers unique perspectives on establishing genomic resources that may function as a groundwork for detecting probable molecular markers linked to the immune system in shrimp.

The death domain-associated protein suppresses porcine epidemic diarrhea virus replication by interacting with signal transducer and activator of transcription 1 and inducing downstream ISG15 expression

Porcine epidemic diarrhea virus (PEDV) is an enteric coronavirus that causes acute enteric disease in piglets and severely threatens the pig industry all over the world. Death domain-associated protein (DAXX) is a classical chaperone protein involved in multiple biological processes, such as cell apoptosis, transcriptional regulation, DNA damage repair, and host innate immunity. However, whether DAXX functions in the anti-PEDV innate immune responses remains unclear. In this study, we found that PEDV infection upregulated DAXX expression and induced its nucleocytoplasmic translocation in IPEC-J2 cells. Furthermore, we found that DAXX overexpression was inhibitory to PEDV replication, while downregulation of DAXX by RNA interference facilitated PEDV replication. The antiviral activity of DAXX was due to its positive effect on IFN-λ3-STAT1 signaling, as DAXX positively regulated STAT1 activation through their interaction in cytoplasm and enhancing the downstream ISG15 expression. Mutation of tryptophan at 621 to alanine in DAXX increased its abundance in the cytoplasm, leading to the upregulation of STAT1 phosphorylation and ISG15 expression. It indicated that cytoplasmic fraction of DAXX was advantageous for the STAT1-ISG15 signaling axis and PEDV inhibition. In summary, these results show that DAXX inhibits PEDV infection by increasing IFN-λ3-induced STAT1 phosphorylation and the downstream ISG15 expression.

Sensitization with Fungal Protease Allergen Establishes Long-Lived, Allergenic Th Cell Memory in the Lung

Allergic asthma is a chronic inflammatory disease that affects millions of individuals worldwide. Exposure to allergens produced by a variety of otherwise harmless microbes, including fungi, predisposes individuals to immunopathologic disease upon subsequent encounters with allergen. We developed a mouse model that employs a purified protease produced by Aspergillus (Asp f 13) to investigate the contributions of CD4+ Th cells to recurrent lung inflammation. Notably, memory CD4+ T cells enhanced the eosinophil response of sensitized/rechallenged animals. In addition, memory CD4+ T cells maintained allergenic features, including expression of GATA-binding protein 3 and IL-5. Th2 memory T cells persisted in the peribronchiolar interstitium of the lung and expressed markers of tissue residence, such as CD69, CCR8, and IL-33R. Lastly, we identified a peptide epitope contained within Asp f 13 and generated a peptide-MHC class II tetramer. Using these tools, we further demonstrated the durability and exquisite sensitivity of memory T cells in promoting lung eosinophilia. Our data highlight important features of memory T cells that strengthen the notion that memory T cells are principal drivers of eosinophilic disease in murine models of allergic sensitization and episodic airway inflammation.

Endothelial to mesenchymal transition in the interleukin-1 pathway during aortic aneurysm formation

OBJECTIVE

Endothelial to mesenchymal transition may represent a key link between inflammatory stress and endothelial dysfunction seen in aortic aneurysm disease. Endothelial to mesenchymal transition is regulated by interleukin-1β, and previous work has demonstrated an essential role of interleukin-1 signaling in experimental aortic aneurysm models. We hypothesize that endothelial to mesenchymal transition is present in murine aortic aneurysms, and loss of interleukin-1 signaling attenuates this process.

METHODS

Murine aortic aneurysms were created in novel CDH5-Cre lineage tracking mice by treating the intact aorta with peri-adventitial elastase. Endothelial to mesenchymal transition transcription factors as well as endothelial and mesenchymal cell markers were analyzed via immunohistochemistry and immunofluorescence (n = 10/group). To determine the role of interleukin-1 signaling, endothelial-specific interleukin-1 receptor 1 knockout and wild-type mice (n = 10/group) were treated with elastase. Additionally, C57/BL6 mice were treated with the interleukin-1 receptor 1 antagonist Anakinra (n = 7) or vehicle (n = 8).

RESULTS

Elastase treatment yielded greater aortic dilation compared with controls (elastase 97.0% ± 34.0%; control 5.3% ± 4.8%; P < .001). Genetic deletion of interleukin-1 receptor 1 attenuated aortic dilation (control 126.7% ± 38.7%; interleukin-1 receptor 1 knockout 35.2% ± 14.7%; P < .001), as did pharmacologic inhibition of interleukin-1 receptor 1 with Anakinra (vehicle 146.3% ± 30.1%; Anakinra 63.5% ± 23.3%; P < .001). Elastase treatment resulted in upregulation of endothelial to mesenchymal transition transcription factors (Snail, Slug, Twist, ZNF) and mesenchymal cell markers (S100, alpha smooth muscle actin) and loss of endothelial cell markers (vascular endothelial cadherin, endothelial nitric oxide synthase, von Willebrand factor). These changes were attenuated by interleukin-1 receptor 1 knockout and Anakinra treatment.

CONCLUSIONS

Endothelial to mesenchymal transition occurs in aortic aneurysm disease and is attenuated by loss of interleukin-1 signaling. Endothelial dysfunction through endothelial to mesenchymal transition represents a new and novel pathway in understanding aortic aneurysm disease and may be a potential target for future treatment.

Targeting aryl hydrocarbon receptor to prevent cancer in barrier organs

The skin, lung, and gut are important barrier organs that control how the body reacts to environmental stressors such as ultraviolet (UV) radiation, air pollutants, dietary components, and microorganisms. The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor that plays an important role in maintaining homeostasis of barrier organs. AhR was initially discovered as a receptor for environmental chemical carcinogens such as polycyclic aromatic hydrocarbons (PAHs). Activation of AhR pathways by PAHs leads to increased DNA damage and mutations which ultimately lead to carcinogenesis. Ongoing evidence reveals an ever-expanding role of AhR. Recently, AhR has been linked to immune systems by the interaction with the development of natural killer (NK) cells, regulatory T (Treg) cells, and T helper 17 (Th17) cells, as well as the production of immunosuppressive cytokines. However, the role of AhR in carcinogenesis is not as straightforward as we initially thought. Although AhR activation has been shown to promote carcinogenesis in some studies, others suggest that it may act as a tumor suppressor. In this review, we aim to explore the role of AhR in the development of cancer that originates from barrier organs. We also examined the preclinical efficacy data of AhR agonists and antagonists on carcinogenesis to determine whether AhR modulation can be a viable option for cancer chemoprevention.

Addressing the impact of high glucose microenvironment on the immunosuppressive characteristics of human mesenchymal stem cells

Mesenchymal stem cells (MSCs) are a therapeutically efficient type of stem cells validated by their ability to treat many inflammatory and chronic conditions. The biological and therapeutic characteristics of MSCs can be modified depending on the type of microenvironment at the site of transplantation. Diabetes mellitus (DM) is a commonly diagnosed metabolic disease characterized by hyperglycemia, which alters over time the cellular and molecular functions of many cells and causes their damage. Hyperglycemia can also impact the success rate of MSCs transplantation; therefore, it is extremely significant to investigate the effect of high glucose on the biological and therapeutic attributes of MSCs, particularly their immunomodulatory abilities. Thus, in this study, we explored the effect of high glucose on the immunosuppressive characteristics of human adipose tissue-derived mesenchymal stem cells (hAD-MSCs). We found that hAD-MSCs cultured in high glucose lost their immunomodulatory abilities and became detectable by immune cells. The decline in the immunosuppressive capabilities of hAD-MSCs was mediated by significant decrease in the levels of IDO, IL-10, and complement factor H and substantial increase in the activity of immunoproteasome. The protein levels of AMP-activated protein kinase (AMPK) and phosphofructokinase-1 (PFK-1), which are integral regulators of glycolysis, revealed a marked decline in high glucose exposed MSCs. The findings of our study indicated the possibility of immunomodulatory shift in MSCs after being cultured in high glucose, which can be translationally employed to explain their poor survival and short-lived therapeutic outcomes in diabetic patients.