The CXCL13/CXCR5 Immune Axis in Health and Disease—Implications for Intrathecal B Cell Activities in Neuroinflammation

Effects of anti-CD20 therapy on circulating and intrathecal follicular helper T cell subsets in multiple sclerosis

Follicular helper T (Tfh) cells and their interplay with B cells likely contribute to the pathogenesis of relapsing-remitting multiple sclerosis (RRMS). Tfh cells are enriched in cerebrospinal fluid (CSF) in RRMS, but effects of anti-CD20 therapy are unknown. We investigated Tfh cells in controls, untreated and anti-CD20-treated patients with RRMS using flow cytometry. CSF Tfh cells were increased in untreated patients. Compared to paired blood samples, CD25- Tfh cells were enriched in CSF in RRMS, but not in controls. Contrast-enhancing brain MRI lesions and IgG index correlated with CSF CD25- Tfh cell frequency in untreated patients with RRMS. Anti-CD20 therapy reduced the numbers of circulating PD1+ Tfh cells and CD25- Tfh cells, and the frequency of CSF CD25- Tfh cells. The study suggests that CD25- Tfh cells are recruited to the CSF in RRMS, associated with focal inflammation, and are reduced by anti-CD20 therapy.

LncRNAs involvement in pathogenesis of immune-related disease via regulation of T regulatory cells, an updated review

The pathophysiology of several illnesses, including cancer and autoimmune diseasesdepends on human regulatory T cells (Tregs), and abnormalities in these cells may function as triggers for these conditions. Cancer and autoimmune, and gynecological diseases are associated with the differentiation of the proinflammatory T cell subset TH17 and its balance with the production of Treg. Recently, long non-coding RNAs (lncRNAs) have become important regulatory molecules in a wide range of illnesses. During epigenetic regulation, they can control the expression of important genes at several levels by affecting transcription, post-transcriptional actions, translation, and protein modification. They might connect with different molecules, such as proteins, DNA and RNA, and their structural composition is intricate. Because lncRNAs regulatebiological processes, including cell division, death, and growth, they are linked to severaldiseases. A notable instance of this is the lncRNA NEAT1, which has been the subject of several investigations to ascertain its function in immune cell development. In the context of immune cell development, several additional lncRNAs have been connected to Treg cell differentiation. In this work, we summarize current findings about the diverse functions of lncRNAs in Treg cell differentiation and control of the Th17/Treg homeostasis in autoimmune disorders, cancers, as well as several gynecological diseases where Tregs are key players.

B cells and the stressed brain: emerging evidence of neuroimmune interactions in the context of psychosocial stress and major depression

The immune system has emerged as a key regulator of central nervous system (CNS) function in health and in disease. Importantly, improved understanding of immune contributions to mood disorders has provided novel opportunities for the treatment of debilitating stress-related mental health conditions such as major depressive disorder (MDD). Yet, the impact to, and involvement of, B lymphocytes in the response to stress is not well-understood, leaving a fundamental gap in our knowledge underlying the immune theory of depression. Several emerging clinical and preclinical findings highlight pronounced consequences for B cells in stress and MDD and may indicate key roles for B cells in modulating mood. This review will describe the clinical and foundational observations implicating B cell-psychological stress interactions, discuss potential mechanisms by which B cells may impact brain function in the context of stress and mood disorders, describe research tools that support the investigation of their neurobiological impacts, and highlight remaining research questions. The goal here is for this discussion to illuminate both the scope and limitations of our current understanding regarding the role of B cells, stress, mood, and depression.

The multifaceted role of the CXC chemokines and receptors signaling axes in ALS pathophysiology

Amyotrophic lateral sclerosis (ALS) is a late-onset motor neuron disease with complex genetic basis and still no clear etiology. Multiple intertwined layers of immune system-related dysfunctions and neuroinflammatory mechanisms are emerging as substantial determinants in ALS onset and progression. In this review, we collect the increasingly arising evidence implicating four main CXC chemokines/cognate receptors signaling axes (CXCR1/2-CXCL1/2/8; CXCR3-CXCL9/10/11; CXCR4/7-CXCL12; CXCR5-CXCL13) in the pathophysiology of ALS. Findings in preclinical models implicate these signaling pathways in motor neuron toxicity and neuroprotection, while in ALS patients dysregulation of CXCLs/CXCRs has been shown at both central and peripheral levels. Immunological monitoring of CXC-ligands in ALS may allow tracking of disease progression, while pharmacological modulation of CXC-receptors provides a novel therapeutic strategy. A deeper understanding of the interplay between CXC-mediated neuroinflammation and ALS is crucial to advance research into treatments for this debilitating uncurable disorder.

Recombinant Acetylcholine Receptor Immunization Induces a Robust Model of Experimental Autoimmune Myasthenia Gravis in Mice

Myasthenia gravis (MG) is a prototypical autoimmune disease of the neuromuscular junction (NMJ). The study of the underlying pathophysiology has provided novel insights into the interplay of autoantibodies and complement-mediated tissue damage. Experimental autoimmune myasthenia gravis (EAMG) emerged as a valuable animal model, designed to gain further insight and to test novel therapeutic approaches for MG. However, the availability of native acetylcholine receptor (AChR) protein is limited favouring the use of recombinant proteins. To provide a simplified platform for the study of MG, we established a model of EAMG using a recombinant protein containing the immunogenic sequence of AChR in mice. This model recapitulates key features of EAMG, including fatigable muscle weakness, the presence of anti-AChR-antibodies, and engagement of the NMJ by complement and a reduced NMJ density. Further characterization of this model demonstrated a prominent B cell immunopathology supported by T follicular helper cells. Taken together, the herein-presented EAMG model may be a valuable tool for the study of MG pathophysiology and the pre-clinical testing of therapeutic applications.

Chemically Functionalized Single-Walled Carbon Nanotubes Prevent the Reduction in Plasmalemmal Glutamate Transporter EAAT1 Expression in, and Increase the Release of Selected Cytokines from, Stretch-Injured Astrocytes in Vitro

We tested the effects of water-soluble single-walled carbon nanotubes, chemically functionalized with polyethylene glycol (SWCNT-PEG), on primary mouse astrocytes exposed to a severe in vitro simulated traumatic brain injury (TBI). The application of SWCNT-PEG in the culture media of injured astrocytes did not affect cell damage levels, when compared to those obtained from injured, functionalization agent (PEG)-treated cells. Furthermore, SWCNT-PEG did not change the levels of oxidatively damaged proteins in astrocytes. However, this nanomaterial prevented the reduction in plasmalemmal glutamate transporter EAAT1 expression caused by the injury, rendering the level of EAAT1 on par with that of control, uninjured PEG-treated astrocytes; in parallel, there was no significant change in the levels of GFAP. Additionally, SWCNT-PEG increased the release of selected cytokines that are generally considered to be involved in recovery processes following injuries. As a loss of EAATs has been implicated as a culprit in the suffering of human patients from TBI, the application of SWCNT-PEG could have valuable effects at the injury site, by preventing the loss of astrocytic EAAT1 and consequently allowing for a much-needed uptake of glutamate from the extracellular space, the accumulation of which leads to unwanted excitotoxicity. Additional potential therapeutic benefits could be reaped from the fact that SWCNT-PEG stimulated the release of selected cytokines from injured astrocytes, which would promote recovery after injury and thus counteract the excess of proinflammatory cytokines present in TBI.

Spatial transcriptomics identifies candidate stromal drivers of benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is the nodular proliferation of the prostate transition zone in older men, leading to urinary storage and voiding problems that can be recalcitrant to therapy. Decades ago, John McNeal proposed that BPH originates with the "reawakening" of embryonic inductive activity by adult prostate stroma, which spurs new ductal proliferation and branching morphogenesis. Here, by laser microdissection and transcriptional profiling of the BPH stroma adjacent to hyperplastic branching ducts, we identified secreted factors likely mediating stromal induction of prostate glandular epithelium and coinciding processes. The top stromal factors were insulin-like growth factor 1 (IGF1) and CXC chemokine ligand 13 (CXCL13), which we verified by RNA in situ hybridization to be coexpressed in BPH fibroblasts, along with their cognate receptors (IGF1R and CXCR5) on adjacent epithelium. In contrast, IGF1 but not CXCL13 was expressed in human embryonic prostate stroma. Finally, we demonstrated that IGF1 is necessary for the generation of BPH-1 cell spheroids and patient-derived BPH cell organoids in 3D culture. Our findings partially support historic speculations on the etiology of BPH and provide what we believe to be new molecular targets for rational therapies directed against the underlying processes driving BPH.

CXCL13 in Cerebrospinal Fluid: Clinical Value in a Large Cross-Sectional Study

C-X-C-motif chemokine ligand 13 (CXCL13) in cerebrospinal fluid (CSF) is increasingly used in clinical routines, although its diagnostic specificity and divergent cut-off values have been defined so far mainly for neuroborreliosis. Our aim was to evaluate the value of CSF-CXCL13 as a diagnostic and treatment response marker and its role as an activity marker in a larger disease spectrum, including neuroborreliosis and other neuroinflammatory and malignant CNS-disorders. Patients who received a diagnostic lumbar puncture (LP) (n = 1234) between July 2009 and January 2023 were included in our retrospective cross-sectional study. The diagnostic performance of CSF-CXCL13 for acute neuroborreliosis was highest at a cut-off of 428.92 pg/mL (sensitivity: 92.1%; specificity: 96.5%). In addition, CXCL13 levels in CSF were significantly elevated in multiple sclerosis with clinical (p = 0.001) and radiographic disease activity (p < 0.001). The clinical utility of CSF-CXCL13 appears to be multifaceted. CSF-CXCL13 is significantly elevated in patients with neuroborreliosis and shows a rapid and sharp decline with antibiotic therapy, but it is not specific for this disease and is also highly elevated in less common subacute neuroinfectious diseases, such as neurosyphilis and cryptococcal meningitis or in primary/secondary B-cell lymphoma.

Role and application of chemokine CXCL13 in central nervous system lymphoma

Chemokine ligand 13 (CXCL13) and its chemokine receptor 5 (CXCR5) both play significant roles in the tumor microenvironment (TME). CXCL13 in cerebrospinal fluid (CSF) has recently been found to have significant diagnostic and prognostic value in primary and secondary central nervous system (CNS) diffuse large B-cell lymphoma (DLBCL), and the CXCL13-CXCR5 axis has been shown to play an important chemotactic role in the TME of CNS-DLBCL. In this review, we first describe the clinical value of CXCL13 in CSF as a prognostic and diagnostic biomarker for CNS-DLBCL. In addition, this review also discusses the specific mechanisms associated with the CXCL13-CXCR5 axis in tumor immunity of primary diffuse large B cell lymphoma of the central nervous system (PCNS-DLBCL) by reviewing the specific mechanisms of this axis in the immune microenvironment of DLBCL and CNS inflammation, as well as the prospects for the use of CXCL13-CXCR5 axis in immunotherapy in PCNS-DLBCL.

Cytokine and Chemokine Production in Mice Inoculated with NVX-CoV2373 (Nuvaxovid®) in Comparison with Omicron BA.4/5 Bivalent BNT162b2 (Comirnaty®)

A recombinant SARS-CoV-2 spike protein vaccine (NVX-CoV2373) has been licensed and has a lesser incidence of adverse events. To know the immunological mechanisms of adverse events, the production of cytokines and chemokines was investigated in mice inoculated with NVX-CoV2373. Serum IL-6 was detected on Day 1 of the first and second doses and the IFN-γ, IL-4, IL-10, TNF-α, and IL-6 levels increased on Day 1 of the second dose at the inoculation site. The enhanced production of the inflammatory chemokines (CCL2), homeostatic chemokine (CXCL13), and Th2 chemokine (CCL17) was observed at the inoculation site on Day 1 of the second dose. These findings were compared with data obtained following inoculation with BNT162b2 bivalent vaccine containing omicron BA.4/5. Significantly lower levels of inflammatory chemokines were detected on Day 1 after the first dose of NVX-CoV2373 in sera and inoculation site than those following inoculation with bivalent BNT162b2 (p < 0.01), reflecting a lower incidence of adverse events after immunization with NVX-CoV2373 in humans. NVX-CoV2373 induced significantly higher concentrations of IFN-γ, TNF-α, and IL-10 at the inoculation site obtained on Day 1 of the second dose (p < 0.05). Significant higher levels of Th2 chemokines, CCL11 and CCL17, were induced at the inoculation site on Day 1 of the second dose (p < 0.01) and they explain the booster IgG EIA antibody response after the second dose of NVX-CoV2373.

Dietary Polyphenols Decrease Chemokine Release by Human Primary Astrocytes Responding to Pro-Inflammatory Cytokines

Astrocytes are considered to be the dominant cell fraction of the central nervous system. They play a supportive and protective role towards neurons, and regulate inflammatory processes; they thus make suitable targets for drugs and supplements, such as polyphenolic compounds. However, due to their wide range, knowledge of their anti-inflammatory potential remains relatively incomplete. The aim of this study was therefore to determine whether myricetin and chrysin are able to decrease chemokine release in reactive astrocytes. To assess the antioxidant and anti-inflammatory potential of polyphenols, human primary astrocytes were cultured in the presence of a reactive and neurotoxic astrocyte-inducing cytokine mixture (TNF-α, IL-1a, C1q), either alone or in the presence of myricetin or chrysin. The examined polyphenols were able to modify the secretion of chemokines by human cortical astrocytes, especially CCL5 (chrysin), CCL1 (myricetin) and CCL2 (both), while cell viability was not affected. Surprisingly, the compounds did not demonstrate any antioxidant properties in the astrocyte cultures.

Advances in immune response to pulmonary infection: Nonspecificity, specificity and memory

The lung immune response consists of various cells involved in both innate and adaptive immune processes. Innate immunity participates in immune resistance in a nonspecific manner, whereas adaptive immunity effectively eliminates pathogens through specific recognition. It was previously believed that adaptive immune memory plays a leading role during secondary infections; however, innate immunity is also involved in immune memory. Trained immunity refers to the long-term functional reprogramming of innate immune cells caused by the first infection, which alters the immune response during the second challenge. Tissue resilience limits the tissue damage caused by infection by controlling excessive inflammation and promoting tissue repair. In this review, we summarize the impact of host immunity on the pathophysiological processes of pulmonary infections and discuss the latest progress in this regard. In addition to the factors influencing pathogenic microorganisms, we emphasize the importance of the host response.

Phenotypic and functional alteration of CD45+ immune cells in the decidua of preeclampsia patients analyzed by mass cytometry (CyTOF)

Preeclampsia (PE) is a severe placenta-related pregnancy disease that has been associated with maternal systemic inflammation and immune system disorders. However, the distribution and functional changes in immune cells of the maternal-placental interface have not been well characterized. Herein, cytometry by time-of-flight mass spectrometry (CyTOF) was used to investigate the immune atlas at the decidua, which was obtained from four PE patients and four healthy controls. Six superclusters were identified, namely, T cells, B cells, natural killer (NK) cells, monocytes, granulocytes, and others. B cells were significantly decreased in the PE group, among which the reduction in CD27+CD38+ regulatory B cell (Breg)-like cells may stimulate immune activation in PE. The significantly increased migration of B cells could be linked to the significantly overexpressed chemokine C-X-C receptor 5 (CXCR5) in the PE group, which may result in the production of excessive autoantibodies and the pathogenesis of PE. A subset of T cells, CD11c+CD8+ T cells, was significantly decreased in PE and might lead to sustained immune activation in PE patients. NK cells were ultimately separated into four subsets. The significant reduction in a novel subset of NK cells (CD56-CD49a-CD38+) in PE might have led to the failure to suppress inflammation at the maternal-fetal interface during PE progression. Moreover, the expression levels of functional markers were significantly altered in the PE group, which also inferred that shifts in the decidual immune state contributed to the development of PE and might serve as potential treatment targets. This is a worthy attempt to elaborate the differences in the phenotype and function of CD45+ immune cells in the decidua between PE and healthy pregnancies by CyTOF, which contributes to understand the pathogenesis of PE, and the altered cell subsets and markers may inspire the immune modulatory therapy for PE.