Beyond T cell toxicity - Intrathecal chemokine CXCL13 indicating B cell involvement in immune-related adverse events following checkpoint inhibition: A two-case series and literature review.

BACKGROUND AND PURPOSE: This study was undertaken to raise awareness of a role of B cells in immune checkpoint inhibitor (ICI)-associated neurological immune-related adverse events (nirAE). METHODS: A systematic literature review was made, with case observations of a melanoma and a non-small cell lung cancer (NSCLC) patient who developed ICI-associated nirAE with cerebrospinal fluid (CSF) findings indicating B cell involvement. RESULTS: Two patients receiving ipilimumab/nivolumab for melanoma and chemotherapy/pembrolizumab for NSCLC developed nirAE in the form of myocarditis/myositis/myasthenia gravis overlap syndrome (triple M) and cerebellitis plus longitudinal transverse myelitis (c-LETM), respectively. Intrathecal inflammation with chemokine C-X-C motif ligand (CXCL13) elevation was present in both patients; the triple M case had acetylcholine receptor antibodies, antititin reactivity, altered CD4/CD8 T cell ratio in blood, and depressed programmed death-1 (PD-1) expression on CSF T cells; the c-LETM case showed intrathecal antibody production and plasma cells. Both patients insufficiently responded to first-line treatment. The NSCLC case improved upon administration of B cell-depleting therapy with rituximab, whereas the melanoma patient died before escalation therapy was initiated. Literature research revealed one additional ICI-associated LETM case with intrathecal CXCL13 elevation, three cases with ICI-associated aquaporin-4 antibody neuromyelitis spectrum disorder, and evidence of B cell-mediated toxicity based on antibody-mediated immune pathologies in ICI-associated immune-related adverse events. CONCLUSIONS: The case observations highlight the plethora of uncertainties in diagnosis and treatment of ICI-associated nirAE, exemplify the heterogeneity of immune mechanisms involved, and suggest a role of B cells, which may be underdiagnosed. Intrathecal CXCL13 may serve as a biomarker of B cell involvement in nirAE, supported by intrathecal immunoglobulin synthesis, presence of plasma cells, and/or recruitment of cognate immune cells.

Unraveling the Heterogeneity of CD8+ T-Cell Subsets in Liver Cirrhosis: Implications for Disease Progression.

Background/Aims: : Liver cirrhosis involves chronic inflammation and progressive fibrosis. Among various immune cells, CD8+ T cells are considered a major contributor to hepatic inflammation and fibrosis. However, the exact molecular pathways governing CD8+ T-cell-mediated effects in cirrhosis remain unclear. Methods: : This study analyzed transcriptomic and single-cell sequencing data to elucidate CD8+ T-cell heterogeneity and implications in cirrhosis. Results: : Weighted gene co-expression analysis of bulk RNA-seq data revealed an association between cirrhosis severity and activated T-cell markers like HLA and chemokine genes. Furthermore, single-cell profiling uncovered eight CD8+ T-cell subtypes, notably, effector memory (Tem) and exhausted (Tex) T cells. Tex cells, defined by PDCD1, LAG3, and CXCL13 expression, were increased in cirrhosis, while Tem cells were decreased. Lineage tracing and differential analysis highlighted CXCL13+ Tex cells as a terminal, exhausted subtype of cells with roles in PD-1 signaling, glycolysis, and T-cell regulation. CXCL13+ Tex cells displayed T-cell exhaustion markers like PDCD1, HAVCR2, TIGIT, and TNFRSF9. Functional analysis implicated potential roles of these cells in immunosuppression. Finally, a CXCL13+ Tex-cell gene signature was found that correlated with cirrhosis severity and poorer prognosis of liver cancer. Conclusions: : In summary, this comprehensive study defines specialized CD8+ T-cell subpopulations in cirrhosis, with CXCL13+ Tex cells displaying an exhausted phenotype associated with immune dysregulation and advanced disease. Key genes and pathways regulating these cells present potential therapeutic targets.

The Possible Role of Anti- and Protumor-Infiltrating Lymphocytes in Pathologic Complete Response in Early Breast Cancer Patients Treated with Neoadjuvant Systemic Therapy.

The tumor microenvironment, composed of pro- and antitumor immune cells, affects cancer cell behavior. We aimed to evaluate whether tumor-infiltrating lymphocyte (TIL) density and TIL subtypes in core biopsies at the diagnosis of breast cancer patients could predict a pathologic complete response (pCR; ypT0/is ypN0) from neoadjuvant systemic therapy (NST). The TIL subtypes were determined based on the proportions of presumably antitumor (CD8+, CXCL13+) and protumor (PD-1+, FOXP3+) immune cells. A prospective, noninterventional study, including 171 participants undergoing NST, was performed. The median TIL density for the entire cohort was 10% (IQR: 3.5-23.8), and 59 (35%) patients achieved pCR. TIL density was positively associated with pCR (univariately and multivariably). In the multivariable logistic regression model, TIL density was an independent predictor of pCR (p = 0.012, OR 1.27; 95% CI 1.05-1.54) when controlled for age (p = 0.232), Ki-67 (p = 0.001), node-negative status (p = 0.024), and HER2+/triple negative vs. luminal B-like subtype (p < 0.001). In our sample, higher proportions of PD-1+ TILs and FOXP3+ TILs were associated with a higher probability of pCR but the association was not statistically significant and we could not make any conclusions on the direction of associations in the model with all four biomarkers. In the exploratory multivariable analysis, we showed that only higher CD8+ TILs were associated with pCR. In conclusion, TIL density and its subtypes are associated with pCR.

Role of C-X-C motif chemokine 13 in sepsis-associated encephalopathy in mice / 中华麻醉学杂志

Objective To evaluate the role of C-X-C motif chemokine 13 (CXCL13) in sepsis-associated encephalopathy in mice.Methods A total of 64 healthy male C57BL/6J mice,aged 3-4 months,weighing 20-25 g,were divided into 4 groups (n=16 each) using a random number table method:sham operation group (Sham group),sepsis group (S group),CXCL13 siRNA group (si-CXCL13 group) and negative control siRNA group (si-control group).5-bromo-2-deoxyuridine (BrdU) 50 mg/kg was intraperitoneally injected twice a day for 3 consecutive days in the four groups,and then lipopolysaccharide 500 μg/kg was intraperitoneally injected to establish the sepsis model in S,si-CXCL13 and si-control groups.CXCL13 siRNA 5 μl and siRNA 5 μl were injected into the left lateral cerebral ventricle in si-CXCL13 and si-control groups,respectively,at 3 days before establishing the model.Morris water maze test was performed at 5 days after establishing the model.The escape latency,time spent in the target quadrant,and the number of crossing the platform were recorded.Mice were sacrificed after the end of test,brains were removed and hippocampi were isolated for examination of the pathological changes of the dentate gyrus (with a light microscope) and for determination of the expression of CXCL13,C-X-C motif chemokine receptor 5 (CXCR5) and brain-derived neurotrophic factor (BDNF),and the number of BrdU and BrdU/NeuroD positive cells (by immunofluorescence).Results Compared with sham group,the escape latency was significantly prolonged,the time spent in the target quadrant was shortened,and the number of crossing the platform was reduced on 2nd-4th days,the number of BrdU positive cells in the dentate gyrus was increased,and the number of BrdU/NeuroD positive cells in the dentate gyrus was decreased in S,siCXCL13 and si-control groups,and the expression of CXCL13 and CXCR5 was up-regulated,and the expression of BDNF was down-regulated in LPS and si-control groups (P＜0.05).Compared with S group,the escape latency was significantly shortened,the time spent in the target quadrant was prolonged,and the number of crossing the platform was increased on 2nd-4th days,the number of BrdU positive cells in the dentate gyrus was decreased,the number of BrdU/NeuroD positive cells in the dentate gyrus was increased,and the expression of CXCL13 and CXCR5 was down-regulated,and the expression of BDNF was up-regulated in si-CXCL13 group (P＜0.05),and no significant change was found in the parameters mentioned above in si-control group (P＞0.05).Conclusion CXCL13 is involved in sepsis-associated encephalopathy through regulating hippocampal neurogenesis,and the mechanism may be related to down-regulating the expression of hippocampal BDNF in mice.

The cerebrospinal fluid in multiple sclerosis: far beyond the bands / O líquido cefalorraquidiano na esclerose múltipla: muito além das bandas

ABSTRACT The cerebrospinal fluid analysis has been employed for supporting multiple sclerosis diagnosis and ruling out the differential diagnoses. The most classical findings reflect the inflammatory nature of the disease, including mild pleocytosis, mild protein increase, intrathecal synthesis of immunoglobulin G, and, most typically, the presence of oligoclonal bands. In recent years, new biomarkers have emerged in the context of multiple sclerosis. The search for new biomarkers reflect the need of a better evaluation of disease activity, disease progression, and treatment efficiency. A more refined evaluation of disease and therapy status can contribute to better therapeutic choices, particularly in escalation of therapies. This is very relevant taking into account the availability of a greater number of drugs for multiple sclerosis treatment in recent years. In this review, we critically evaluate the current literature regarding the most important cerebrospinal fluid biomarkers in multiple sclerosis. The determination of biomarkers levels, such as chemokine ligand 13, fetuin A, and mainly light neurofilament has shown promising results in the evaluation of this disease, providing information that along with clinical and neuroimaging data may contribute to better therapeutic decisions.

RESUMO A análise do líquido cefalorraquidiano tem sido empregada para avaliação diagnóstica da esclerose múltipla e a exclusão dos diagnósticos diferenciais. Os achados clássicos refletem a natureza inflamatória da doença, incluindo discreta pleocitose, leve hiperproteinorraquia, aumento da síntese intratecal de imunoglobulina G e, mais tipicamente, a presença de bandas oligoclonais. Nos últimos anos, surgiram novos biomarcadores para esclerose múltipla, e esta busca por marcadores reflete a necessidade de melhor avaliar a atividade e a progressão da doença, bem como a eficácia terapêutica. Uma avaliação mais refinada da atividade da doença e da resposta aos medicamentos pode contribuir para melhores decisões terapêuticas, particularmente no que se refere à troca de medicação. Isto é muito importante nos dias de hoje, quando surgem novas opções medicamentosas. Neste artigo de revisão, avaliamos criticamente a literatura atual referente aos novos marcadores liquóricos na esclerose múltipla. A mensuração destes marcadores, como a quimiocina CXCL13, fetuína A e, principalmente, o neurofilamento de cadeia leve, demonstrou resultados promissores na avaliação da doença, provendo informações que, em conjunto com dados clínicos e de neuroimagem, podem contribuir para melhores decisões terapêuticas.

Relationships between the level of chemokine CXCL13 and the distribution of Tfh subsets in peripheral blood of hepatitis B patients and their clinical significance / 中华微生物学和免疫学杂志

Objective To investigate the distribution of T follicular helper(Tfh)cell subsets in hepa-titis B patients at different immune stages and to clarify the relationships between the level of CXCL13 and the distribution of Tfh cell subsets. Methods Flow cytometry analysis was performed to detect the distribution of Tfh cells. Enzyme-linked immunosorbent assay(ELISA)was performed to measure the levels of CXCL13 in ser-um samples collected from hepatitis B patients. RT-PCR and Western blot assay were used to analyze the expres-sion of CXCL13 in HepG2 and HepG2. 2. 1. 5 cells. Results The percentages of Tfh1 cells were significantly up-regulated at the immune activation(IA)stage,while those of Tfh2 cells were significantly raised at the im-mune tolerance(IT)stage. The percentages of Tfh17 cells in patients at the stage of IT were similar to those in patients at the stage of IA,but were higher than those in responders with HBsAg seroconversion(RP)or healthy controls(HC). The expression of CXCL13 was positively correlated with the percentage of Tfh2 cells. More over,hepatitis B virus(HBV)enhanced the expression of CXCL13 at both transcriptional and translational lev-els. Conclusion HBV might up-regulate the percentage of Tfh2 cells through promoting the expression of CXCL13,which resulted in the induction of immune tolerance. Elucidating the functions of Tfh1,Tfh2 and Tfh17 cells and understanding the type conversion mechanism among the three subsets are important for further researches on HBV-induced immunosuppression.

Elevated serum levels of visfatin in patients with henoch-schönlein purpura.

BACKGROUND: Henoch-Schönlein purpura (HSP) is an immune complex-mediated disease predominantly characterized by the deposition of circulating immune complexes containing immunoglobulin A (IgA) on the walls of small vessels. Although the pathogenesis of HSP is not yet fully understood, some researchers proposed that B-cell activation might play a critical role in the development of this disease. OBJECTIVE: To investigate the serum levels of visfatin (pre-B-cell colony-enhancing factor), B-cell-activating factor (BAFF), and CXCL13, and to analyze their association with disease severity. METHODS: The serum levels of visfatin, BAFF, and CXCL13 were measured by using a double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) in 43 patients with HSP and 45 controls. The serum levels of IgA anticardiolipin antibodies (ACA) were detected by using a double-antigen sandwich ELISA. RESULTS: Levels of visfatin but not BAFF and CXCL13 were significantly elevated in the sera of patients with HSP in the acute stage, and restored to normal levels in the convalescent stage. Furthermore, serum levels of visfatin were significantly higher in patients with HSP having renal involvement than in those without renal involvement. Serum levels of visfatin were correlated with the severity of HSP and serum concentration of ACA-IgA. CONCLUSION: We show for the first time that the serum levels of visfatin are abnormally elevated in patients with HSP. Visfatin may be associated with the pathogenesis of HSP.

Elevated Serum Levels of Visfatin in Patients with Henoch-Schonlein Purpura

BACKGROUND: Henoch-Schonlein purpura (HSP) is an immune complex-mediated disease predominantly characterized by the deposition of circulating immune complexes containing immunoglobulin A (IgA) on the walls of small vessels. Although the pathogenesis of HSP is not yet fully understood, some researchers proposed that B-cell activation might play a critical role in the development of this disease. OBJECTIVE: To investigate the serum levels of visfatin (pre-B-cell colony-enhancing factor), B-cell-activating factor (BAFF), and CXCL13, and to analyze their association with disease severity. METHODS: The serum levels of visfatin, BAFF, and CXCL13 were measured by using a double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) in 43 patients with HSP and 45 controls. The serum levels of IgA anticardiolipin antibodies (ACA) were detected by using a double-antigen sandwich ELISA. RESULTS: Levels of visfatin but not BAFF and CXCL13 were significantly elevated in the sera of patients with HSP in the acute stage, and restored to normal levels in the convalescent stage. Furthermore, serum levels of visfatin were significantly higher in patients with HSP having renal involvement than in those without renal involvement. Serum levels of visfatin were correlated with the severity of HSP and serum concentration of ACA-IgA. CONCLUSION: We show for the first time that the serum levels of visfatin are abnormally elevated in patients with HSP. Visfatin may be associated with the pathogenesis of HSP.

Role of chemokine CXC ligand 13 in spinal cord in neuropathic pain in rats / 中华麻醉学杂志

Objective To evaluate the role of chemokine CXC ligand 13 (CXCL13) in spinal cord in neuropathic pain (NP) in rats.Methods One hundred and eight male Sprague-Dawley rats,weighing 150-200 g,were randomly divided into 4 groups (n =27 each):sham operation group (group S),group NP,small interference RNA (siRNA) negative control group (group NS) and CXCL13-siRNA group (group CS).The animals were anesthetized with intraperitoneal ketamine 50 mg/kg.NP was induced by ligation of L5 spinal nerve (SNL) in groups NP,NS and CS.L5 spinal nerve was only exposed but not occluded in group S.CXCL13-siRNA lentivirus and siRNA negative control lentivirus were injected intrathecally in groups CS and NS,respectively.Mechanical pain threshold was measured at 3,7 and 14 days after SNL.Then the rats were sacrificed and L4-6 segments of the spinal cord were obtained for determination of coexpression of CXCL13 and Neun (by immunofluorescence),activation of astrocytes,and expression of CXCL13 and glial fibrillary acidic protein (GFAP) protein (by Western blot) and mRNA (by RT-PCR) in spinal cord tissues.Results Compared with group S,mechanical pain threshold was significantly decreased and the expression of CXCL13 and GFAP protein and mRNA was up-regulated at each time point after operation in groups NP,NS and CS (P ＜ 0.05).Compared with group NP,mechanical pain threshold was significantly increased and the expression of CXCL13 and GFAP protein and mRNA was down-regulated at each time point after operation in group CS (P ＜ 0.05).There was no significant difference in the indexes mentioned above at each time point after operation between groups NP and NS (P ＞ 0.05).Conclusion CXCL13 is involved in the development and maintenance of NP in rats via activation of astrocytes.

LPS-induced migration of peritoneal B-1 cells is associated with upregulation of CXCR4 and increased migratory sensitivity to CXCL12.

B-1 cells, which constitute a predominant lymphocyte subset in serosal cavities and produce most of natural antibodies, are subdivided into the CD5(+) B-1a and CD5(-) B-1b cell subpopulations, but the differential roles of B-1a and B-1b cells are not well understood. We report that B-1a cells preferentially migrate out of the peritoneal cavity and upregulate the expression of CXCR4 with heightened sensitivity to CXCL12 and CXCL13 upon LPS treatment compared to B-1b and B-2 cells. Whereas B-1a cells were slightly more abundant than B-1b and B-2 cells in the homeostatic condition, the number of B-1a cells preferentially decreased 48 hr after LPS treatment. The decrease in the peritoneal B-1a cell number was accompanied with increased migration of B-1a cells toward CXCL-12 and CXCL-13 in in vitro transmigration assay using peritoneal B cells from LPS treated mice. The expression level of CXCR4, but not of CXCR5, was also more prominently increased in B-1a cells upon LPS stimulation. LPS-stimulated B-1a cells did not accumulate in omental milky spots in contrast to B-2 cells. These results suggest that B-1a cells actively migrate out of the peritoneal cavity through the regulation of the migratory responsiveness to chemokines and actively participate in systemic immune responses.

LPS-Induced Migration of Peritoneal B-1 Cells is Associated with Upregulation of CXCR4 and Increased Migratory Sensitivity to CXCL12

B-1 cells, which constitute a predominant lymphocyte subset in serosal cavities and produce most of natural antibodies, are subdivided into the CD5+ B-1a and CD5- B-1b cell subpopulations, but the differential roles of B-1a and B-1b cells are not well understood. We report that B-1a cells preferentially migrate out of the peritoneal cavity and upregulate the expression of CXCR4 with heightened sensitivity to CXCL12 and CXCL13 upon LPS treatment compared to B-1b and B-2 cells. Whereas B-1a cells were slightly more abundant than B-1b and B-2 cells in the homeostatic condition, the number of B-1a cells preferentially decreased 48 hr after LPS treatment. The decrease in the peritoneal B-1a cell number was accompanied with increased migration of B-1a cells toward CXCL-12 and CXCL-13 in in vitro transmigration assay using peritoneal B cells from LPS treated mice. The expression level of CXCR4, but not of CXCR5, was also more prominently increased in B-1a cells upon LPS stimulation. LPS-stimulated B-1a cells did not accumulate in omental milky spots in contrast to B-2 cells. These results suggest that B-1a cells actively migrate out of the peritoneal cavity through the regulation of the migratory responsiveness to chemokines and actively participate in systemic immune responses.