CXCL13/CXCR5 axis facilitates TFH expansion and correlates with disease severity in adults with immune thrombocytopenia.

BACKGROUND: Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder defined by a diminished platelet count. ITP pathogenesis involves intricate changes to both cellular and humoral immunity. The pivotal roles of follicular helper T (TFH) cells in the maturations of B cells and the production of antibodies are well-established. However, the specific role of TFH to the immunopathogenesis of ITP remain incompletely understood. This study aimed to clarify the association of CXCL13/CXCR5 axis with TFH in adults with ITP. METHODS: A total of 97 ITP patients and 41 healthy controls were enrolled. CD4+CXCR5+ TFH, CD4+CXCR5+PD-1+ TFH, CD4+CXCR5+Foxp3+ follicular regulatory T cells (TFR), and desialylated platelets in peripheral blood were measured by flow cytometry. Plasma cytokines were assessed by enzyme-linked immunosorbent assay. CD4+ T cells cocultured with chemokine CXCL13 in vitro was performed for the measurement of TFH proliferation. Intracellular production of reactive oxygen species (ROS) was examined by dichlorodihydrofluorescein diacetate (DCFH-DA) probe staining. RESULTS: We observed a significant increase in circulating TFH and a marked decrease in circulating TFR in the entire ITP cohort. The ratio of TFH/TFR was elevated, accompanied by heightened levels of platelet desialylation, cytokines BAFF, HMGB1, and IL-21, while levels of IL-10 were downregulated in adults with ITP. Notably, patients with ITP exhibiting platelet count below 50 × 109/L had dramatically elevated levels in both chemokine CXCL13 and its receptor CXCR5+ TFH compared to those with platelet count above 100 × 109/L. High frequencies of TFH correlated with poor therapeutic response. Furthermore, in vitro CD4+ T cell proliferation assay demonstrated a CXCL13 dose-dependent increase in the frequencies in both CD4+CXCR5+ TFH and CD4+CXCR5+PD-1+ TFH from ITP patients. Intriguingly, DCFH-DA assay illustrated a significant enhancement in intracellular ROS generation in CXCR5+ T cell subsets, especially in CD4+CXCR5+PD-1+ TFH from 4 patients with ITP. CONCLUSIONS: These results underscore the pivotal role of CXCL13/CXCR5 axis-drived TFH expansion in the pathogenesis of ITP, providing a potential disease severity biomarker.

CXCL13: a common target for immune-mediated inflammatory diseases.

CXCL13 is a chemokine that plays an important role in the regulation and development of secondary lymphoid organs. CXCL13 is also involved in the regulation of pathological processes, particularly inflammatory responses, of many diseases. The function of CXCL13 varies depending on the condition of the host. In a healthy condition, CXCL13 is mainly secreted by mouse stromal cells or human follicular helper T cells, whereas in diseases conditions, they are produced by human peripheral helper T cells and macrophages in non-lymphoid tissues; this is termed ectopic expression of CXCL13. Ectopic CXCL13 expression is involved in the pathogenesis of various immune-mediated inflammatory diseases as it regulates the migration of B lymphocytes, T lymphocytes, and other immune cells in inflammatory sites as well as influences the expression of inflammatory factors. Additionally, ectopic expression of CXCL13 plays a key role in ectopic lymphoid organ formation. In this review, we focused on the sources of CXCL13 in different conditions and its regulatory mechanisms in immune-mediated inflammatory diseases, providing novel ideas for further research on targeting CXCL13 for the treatment of immune-mediated inflammatory diseases.

Chemokine CXCL13 facilitates anti-FVIII inhibitory antibody development in hemophilia A patients and murine models.

The development of anti-factor VIII (FVIII) neutralizing antibodies (inhibitors) remains challenging complication in hemophilia A (HA) patients undergoing prophylactic FVIII replacement therapy. The pathogenesis of FVIII inhibitor formation remains unclear. Chemokine CXCL13, a key ligand for follicular helper T cells (TFHs), in the context of inhibitor development were assessed in the present study. A total of 113 HA patients, with and without inhibitors, along with 72 healthy volunteers, were enrolled. Results demonstrated abnormally elevated levels of CXCL13 in HA patients, with a 2.0-fold increase in patients with inhibitors compared to those without. Similarly, CXCL13 levels were significantly elevated in both wild-type and HA mice with FVIII inhibitors. The proportions of circulating and splenic TFHs were markedly higher in inhibitor patients and murine models and positively correlated with CXCL13 levels. Moreover, plasma levels of B cell activating factor and the inflammatory biomarker HMGB1 were significantly increased in both human and animal inhibitor cohorts. An increased frequency of germinal center B cells was observed in splenocytes from inhibitor mice. In vitro study revealed human dermal microvascular endothelial cells undergoing immunogenic ferroptosis when conditioned with high levels of CXCL13, which was associated with down-regulation of ferroptosis suppressors SLC7A11 and GPX4, activation of the Nrf2 pathway, and increased intracellular reactive oxygen species. The findings of this study suggest that CXCL13 play a pivotal role in the microenvironment of anti-FVIII antibody development. Targeting CXCL13 may offer a potential therapeutic approach for FVIII inhibitors in HA.

Chemokine Profile Is Different in Normal Testis Compared to Seminoma - Especially in Tumor Infiltrating Lymphocytes.

BACKGROUND/AIM: Testicular cancers, particularly seminomas and non-seminomas, generally have a favorable prognosis, although a small subset of patients experience mortality. Current knowledge of clinical markers associated with relapse and poor prognosis in seminoma is limited. Chemokines, key proteins in the tumor microenvironment, are underexplored in seminoma prognosis. Additionally, tumor-infiltrating lymphocytes (TILs), which play a critical role in cancer prognosis, require further investigation in the context of seminoma. PATIENTS AND METHODS: Samples from 25 seminoma patients and 24 control patients who underwent orchiectomy were immunohistochemically (IHC) stained for chemokines CXCR4, CXCR5, and their ligands CXCL12, CXCL13, and the proliferation marker Ki-67. The associations between IHC results and clinical presentations were examined. RESULTS: Chemokine profiles differed between seminoma and normal testis. The expression of chemokines in TILs in seminoma samples was especially over-expressed. The cytoplasmic expression of CXCL13 in TILs multiplied by the percentage of TILs in each sample, appeared to approach statistical significance concerning the likelihood of relapse. CONCLUSION: The involvement of TILs in seminoma biology warrants further investigation, especially their role in the tumor micro-environment and pathogenesis. Chemokine and Ki-67 expression in TILs could serve as potential markers for assessing seminoma prognosis.

Intrauterine adhesions repair with menstrual blood-derived mesenchymal stem cells via CXCL13-CXCR5 signal axis and its mechanism.

BACKGROUD: Intrauterine Adhesions (IUA) is a common gynecological disease which is seriously endangers the reproductive function of women without any ideal treatment. Some researchers found Menstrual Blood-derived Mesenchymal Stem Cells (MenSCs) can repair of damaged endometrium, however, has not been fully clarified. This study aims to evaluate the therapeutic effects of MenSCs in IUA and the repair mechanism in vivo. METHODS: This study is Laboratory-based study. To evaluate the therapeutic effects of MenSCs in IUA, We cultivated MenSCs, established mouse endometrial injury model, observed the uterine morphology and degree of endometrial fibrosis and compared the expression of CXC chemokine ligand-13 (CXCL13)、CXC chemokine receptor-5 (CXCR5)、Plasmin Activating Inhibitor-1(Pai-1), Transforming Growth Faction-ß1(TGF- ß1) and Matrix Metalloproteinase-9 (Mmp-9) among each groups. GraphPad Prism 8.0 was used for statistical processing. Data were expressed as mean ± SD. Statistical comparisons among groups were performed with one-way ANOVA. P < 0.05 were considered statistically significant. RESULTS: We successfully cultured and identified MenSCs and established mice model of uterine adhesion. After treatment with MenSCs, endometrial morphology of mice was partially restored, endometrial thickness was increased, and glands were multipiled. The concentrations of CXCL13 and CXCR5 were significantly increased by immunofluorescence detection compared with the control group. The results of RT-qPCR showed that the expressions of Pai-1 and Mmp-9 were significantly lower than those of the control group. CONCLUSIONS: MenSCs may reduce endometrial fibrosis and the down-regulating expression of Pai-1、Mmp-9 and CXCL13-CXCR5 axis were involved in the process of MenSCs repaired IUA.

CXCL13 promotes broad immune responses induced by circular RNA vaccines.

Antibody responses induced by current vaccines for influenza and SARS-CoV-2 often lack robust cross-reactivity. As hubs where diverse immune cells converge and interact, the alterations in the immune microenvironment within lymph nodes (LNs) are intricately linked to immune responses. Herein, we designed a lipid nanoparticle (LNP) loaded with circular RNA (circRNA) and targeted to LNs, in which CXCL13 was directly integrated into antigen-encoding circRNA strands. We demonstrated that CXCL13 alters the transcriptomic profiles of LNs, especially the upregulation of IL-21 and IL-4. Meanwhile, CXCL13 promotes the formation of germinal center and elicits robust antigen-specific T cell responses. With the codelivery of CXCL13 and the antigen, CXCL13 enhances cross-reactive antibodies against influenza virus and SARS-CoV-2, achieving protection against both homologous and heterologous influenza virus challenges in a mouse model. Notably, the targeted modification of LNP surfaces with antibodies helps address some of the challenges associated with lyophilized LNP vaccines, which is crucial for the long-term storage of LNP-circRNA vaccines. Overall, the circRNA-based antigen-CXCL13 coexpression system developed herein provides a simple and robust platform that enhances the magnitude and breadth of antibody responses against multiple viral glycoproteins, highlighting the potential utility of CXCL13 in inducing broad immune responses.

[Cytokine modification by the RNA regulatory protein TFL].

We found a novel gene, named "transformed follicular lymphoma" (TFL), in a patient who developed diffuse large B-cell lymphoma from follicular lymphoma. TFL modulates several cytokines and chemokines by binding their 3'UTR region of mRNA with its unique RNase motif. TFL is part of a family called zinc finger CCCH-type containing 12A-D. Due to its unique RNase motif, the TFL family is also called regulatory RNase (Regnase 1-4). TFL is expressed in lymphoid tissue and is upregulated by an inflammatory response, contributing to autoimmune diseases such as multiple sclerosis via IL-17 in CNS and worsening inflammation (cachexia) due to lymphoma progression through CXCL-13. Loss of TFL expression is reported to be a valuable biomarker for various cancers, including lung adenocarcinoma, endometrial cancer, and possibly lymphoma. In addition to its mRNA modulation function, Regnase1 is known to have deubiquitinase activity for TRAF2, 3, and 6, attenuating JNK and NFκB activity, and TFL captures and transports naked nonvesicular extracellular mRNA of IL-1ß to the nucleus, enhancing the tumor-killing activity in NK cells. Based on its potential to modulate inflammation, TFL could be a future treatment target for autoimmune diseases and cancer.

High serum levels of CXCL13 predict lower response to csDMARDs in both ACPA-positive and ACPA-negative early rheumatoid arthritis.

OBJECTIVES: Increased circulating levels of CXCL13 reflect synovial production and indicate immune dysregulation in patients with rheumatoid arthritis (RA). Here we tested whether CXCL13 predicts response to first-line treatment with methotrexate (MTX) in patients with early RA, independently and in association with anti-citrullinated protein antibodies (ACPA) and IgM-rheumatoid factor (RF). METHODS: A prospective cohort of 243 early RA patients undergoing treat-to-target with MTX was evaluated. CXCL13, ACPA and IgM-RF were determined on baseline sera. Short-term variations of CXCL13 were measured after 2 months. The association of high CXCL13 (≥100 pg/ml) with disease remission after 6 months and escalation to second-line therapies within year 2 was evaluated in the total population and in ACPA-subgroups separately. RESULTS: High levels of CXCL13 were found in 53.6% of ACPA-positive and 31.5% of ACPA-negative patients, with minimal association with disease activity and RF. Serum CXCL13 remained stable after 2 months. High baseline CXCL13 independently predicted failure to achieve remission and more frequent requirement of second-line treatment in ACPA-positive patients, with adjusted ORs in the range of 0.17-0.49 for remission and 6.75 for second-line treatment. In ACPA-negative patients with high CXCL13, remission occurred at the expense of higher doses of MTX, and levels of CXCL13 predicted MTX escalations with an adjusted OR (95% CI) of 2.69 (1.35-5.34). CONCLUSIONS: High serum levels of CXCL13 identify a subgroup of RA patients who are more refractory to first-line treatment with MTX. CXCL13 appears a promising biomarker of response to MTX in both ACPA-positive and -negative early RA.

Chemokine CXCL13-CXCR5 signaling in neuroinflammation and pathogenesis of chronic pain and neurological diseases.

Chronic pain dramatically affects life qualities of the sufferers. It has posed a heavy burden to both patients and the health care system. However, the current treatments for chronic pain are usually insufficient and cause many unwanted side effects. Chemokine C-X-C motif ligand 13 (CXCL13), formerly recognized as a B cell chemokine, binds with the cognate receptor CXCR5, a G-protein-coupled receptor (GPCR), to participate in immune cell recruitments and immune modulations. Recent studies further demonstrated that CXCL13-CXCR5 signaling is implicated in chronic pain via promoting neuroimmune interaction and neuroinflammation in the sensory system. In addition, some latest work also pointed out the involvement of CXCL13-CXCR5 in the pathogenesis of certain neurological diseases, including ischemic stroke and amyotrophic lateral sclerosis. Therefore, we aim to outline the recent findings in regard to the involvement of CXCL13-CXCR5 signaling in chronic pain as well as certain neurological diseases, with the focus on how this chemokine signaling contributes to the pathogenesis of these neurological diseases via regulating neuroimmune interaction and neuroinflammation. Strategies that can specifically target CXCL13-CXCR5 signaling in distinct locations may provide new therapeutic options for these neurological diseases.

Phase I Clinical Trial of CD19 CAR-T Cells Expressing CXCR5 Protein for the Treatment of Relapsed or Refractory B-cell Lymphoma.

BACKGROUND: It is difficult for CD19 CAR-T cells to enter solid tumors, which is one reason for their poor efficacy in lymphoma treatment. The chemokine CXCL13 secreted by stro-mal cells of the lymph nodes induces the homing of B and T lymphocytes, which express its receptor CXCR5. Preclinical trials have shown that the expression of CXCR5 on CD19 CAR-T cells can increase their migration to the tumor microenvironment and enhance their antitumor function. METHODS: We engineered the CD19 CAR-T cells to express a second receptor, CXCR5. Then, we conducted a phase I clinical trial to evaluate the safety and efficacy of CXCR5 CD19 CAR-T cells in the treatment of relapsed or refractory (R/R) B-cell lymphoma. RESULTS: We recruited 10 patients with R/R B-cell lymphoma undergoing CXCR5 CD19 CAR-T cell therapy. The objective response rate was 80%, and the complete response rate was 50%. The median follow-up time was 15.48 months (3.4-22.3 months), and the median Progression-Free Survival (PFS) time was 8.15 months (1.5-22.33 months). One patient received ASCT at 1.5 months (at PR) after infusion of CAR-T cells. The incidence of grade 1 and grade 2 Cytokine Release Syndrome (CRS) was 70% and 20%, respectively. No patient experienced grade 3 or higher levels of CRS, neurotoxicity, or infusion-related dose toxicity. CONCLUSION: The results obtained in this study suggest that CXCR5 CD19 CAR-T cells should be investigated in a trial with broader patient populations. TRIAL REGISTRATION: The trials were registered at www.chictr.org.cn as ChiCTR2100052677 and ChiCTR1900028692.

Unraveling the origins of pathogenic CXCL13+ helper T cells in systemic lupus erythematosus.

This Research Highlight discusses a recent publication, where the authors identified an increase in CXCL13+ peripheral helper T/follicular helper T cells, which was concomitant with a decrease in CD96+ T helper 22 (TH22) cells in patients with systemic lupus erythematosus. The genetic and epigenetic cues that reciprocally regulate this pathogenic imbalance of T-cell subsets were also identified, thus providing targets for therapeutic intervention.

Revisiting the CXCL13/CXCR5 axis in the tumor microenvironment in the era of single-cell omics: Implications for immunotherapy.

As one of the important members of the family of chemokines and their receptors, the CXCL13/CXCR5 axis is involved in follicle formation in normal lymphoid tissues and the establishment of somatic cavity immunity under physiological conditions, as well as being associated with a wide range of infectious, autoimmune, and tumoral diseases. Here in this review, we focus on its role in tumors. Traditional studies have found the axis to be both pro- and anti-tumorigenic, involving a variety of immune cells, including the tumor cells themselves and those in the tumor microenvironment (TME), and the prognostic significance of this axis is clinical context-dependent. With the development of techniques at the single-cell level, we were able to explain in detail the status of the CXCL13/CXCR5 axis in the TME based on real clinical samples and found that it involves a range of crucial intrinsic anti-tumor immune processes in the TME and is therefore important in tumor immunotherapy. We summarize the cellular subsets, physiological functions, and prognostic significance associated with this axis in the most promising immune checkpoint inhibitor (ICI) therapies of the day and summarize possible therapeutic ideas based on this axis. As with any TME study, the most important takeaway is that the complexity of the CXCL13/CXCR5 axis in TME suggests the importance of personalized therapy in tumor therapy.

Sphingosine-1-phosphate receptor type 4 is critically involved in the regulation of peritoneal B-1 cell trafficking and distribution in vivo.

B-1 cells are crucially involved in immune defense and regulation of inflammation and autoimmunity. B-1 cells are predominantly located in the peritoneal and pleural cavities, although body cavity B-1 cells recirculate systemically under steady-state conditions. The chemokines CXCL12 and CXCL13 have been identified as the main regulators of peritoneal B-cell trafficking. In mice deficient for sphingosine-1-phosphate receptor 4 (S1PR4), B-1a and B-1b cell numbers are reduced in the peritoneal cavity by an unknown mechanism. In this study, we show that S1PR4-mediated S1P signaling modifies the chemotactic response of peritoneal B cells to CXCL13 and CXCL12 in vitro. In vivo, S1PR4-mediated S1P signaling affects both immigration into and emigration from the peritoneal cavity. Long-term reconstitution experiments of scid mice with wt or s1pr4 -/- peritoneal B cells revealed a distinct distributional pattern in secondary lymphoid organs. As a functional consequence, both plasmatic and mucosal IgM levels, the main product of B-1a cells, are reduced in mice reconstituted with s1pr4 -/- peritoneal cells. In summary, our data identify S1PR4 as the second S1P receptor (besides S1PR1), which is critically involved in the regulation of peritoneal B-1 cell function.

Syndecan-1 Plays a Role in the Pathogenesis of Sjögren's Disease by Inducing B-Cell Chemotaxis through CXCL13-Heparan Sulfate Interaction.

In Sjögren's disease (SjD), the salivary glandular epithelial cells can induce the chemotaxis of B cells by secreting B-cell chemokines such as C-X-C motif chemokine ligand 13 (CXCL13). Syndecan-1 (SDC-1) is a major transmembrane heparan sulfate proteoglycan (HSPG) predominantly expressed on epithelial cells that binds to and regulates heparan sulfate (HS)-binding molecules, including chemokines. We aimed to determine whether SDC-1 plays a role in the pathogenesis of SjD by acting on the binding of HS to B-cell chemokines. To assess changes in glandular inflammation and SDC-1 concentrations in the submandibular gland (SMG) and blood, female NOD/ShiLtJ and sex- and age-matched C57BL/10 mice were used. In the SMG of NOD/ShiLtJ mice, inflammatory responses were identified at 8 weeks of age, but increased SDC-1 concentrations in the SMG and blood were observed at 6 weeks of age, when inflammation had not yet started. As the inflammation of the SMG worsened, the SDC-1 concentrations in the SMG and blood increased. The expression of the CXCL13 and its receptor C-X-C chemokine receptor type 5 (CXCR5) began to increase in the SMG at 6 weeks of age and continued until 12 weeks of age. Immunofluorescence staining in SMG tissue and normal murine mammary gland cells confirmed the co-localization of SDC-1 and CXCL13, and SDC-1 formed a complex with CXCL13 in an immunoprecipitation assay. Furthermore, NOD/ShiLtJ mice were treated with 5 mg/kg HS intraperitoneally thrice per week for 6-10 weeks of age, and the therapeutic effects in the SMG were assessed at the end of 10 weeks of age. NOD/ShiLtJ mice treated with HS showed attenuated salivary gland inflammation with reduced B-cell infiltration, germinal center formation and CXCR5 expression. These findings suggest that SDC-1 plays a pivotal role in the pathogenesis of SjD by binding to CXCL13 through the HS chain.

Breast cancer during pregnancy of Luminal A type overexpressed CXCL13.

Pregnancy-associated breast cancer has been increasing. In this study, we analyzed patients with breast cancer that occurred during pregnancy (PrBC) and compared their genetic profiles with those of patients with breast cancer that did not occur during pregnancy, within 1 year after childbirth nor during lactation (non-PrBC). We performed gene expression analyses of patients with PrBC and non-PrBC using microarrays and qRT-PCR. Microarray analysis showed that 355 genes were upregulated in the luminal-type PrBC group compared to those in the non-PrBC group. The C-X-C motif chemokine ligand 13 (CXCL13) gene was the most upregulated in the PrBC group compared to that in the non-PrBC group, especially in the luminal A-type (p = 0.016). This result was corroborated by the qRT-PCR analysis of microdissected cancer cells (p < 0.001). A negative correlation was observed between CXCL13 and estrogen receptor 1 (ESR1) mRNA expression levels in luminal A-type breast carcinoma (p < 0.001). Our results provide clues for a better understanding of breast cancer pathogenesis during pregnancy.

Deciphering the interplay of HPV infection, MHC-II expression, and CXCL13+ CD4+ T cell activation in oropharyngeal cancer: implications for immunotherapy.

BACKGROUND: Human papillomavirus (HPV) infection has become an important etiological driver of oropharyngeal squamous cell carcinoma (OPSCC), leading to unique tumor characteristics. However, the interplay between HPV-associated tumor cells and tumor microenvironment (TME) remains an enigma. METHODS: We performed a single-cell RNA-sequencing (scRNA-seq) on HPV-positive (HPV+) and HPV-negative (HPV‒) OPSCC tumors, each for three samples, and one normal tonsil tissue. Ex vivo validation assays including immunofluorescence staining, cell line co-culture, and flow cytometry analysis were used to test specific subtypes of HPV+ tumor cells and their communications with T cells. RESULTS: Through a comprehensive single-cell transcriptome analysis, we uncover the distinct transcriptional signatures between HPV+ and HPV‒ OPSCC. Specifically, HPV+ OPSCC tumor cells manifest an enhanced interferon response and elevated expression of the major histocompatibility complex II (MHC-II), potentially bolstering tumor recognition and immune response. Furthermore, we identify a CXCL13+CD4+ T cell subset that exhibits dual features of both follicular and pro-inflammatory helper T cells. Noteworthily, HPV+ OPSCC tumor cells embrace extensive intercellular communications with CXCL13+CD4+ T cells. Interaction with HPV+ OPSCC tumor cells amplifies CXCL13 and IFNγ release in CD4+T cells, fostering a pro-inflammatory TME. Additionally, HPV+ tumor cells expressing high MHC-II and CXCL13+CD4+ T cell prevalence are indicative of favorable overall survival rates in OPSCC patients. CONCLUSIONS: Together, our study underscores a synergistic inflammatory immune response orchestrated by highly immunogenic tumor cells and CXCL13+CD4+ T cells in HPV+ OPSCC, offering useful insights into strategy development for patient stratification and effective immunotherapy in OPSCC.

Antibody responses to immunoevasion proteins BBK32 and OspE constitute part of the serological footprint in neuroborreliosis but are insufficient to prevent the disease.

Lyme borreliosis, caused by Borrelia burgdorferi sensu lato, is the most common tickborne disease. Its neuronal form, neuroborreliosis, comprises 3 to 38% of borreliosis cases in Europe. Borrelia outer surface proteins and virulence factors, OspE and BBK32, have been previously reported to help cause infection by promoting attachment to human host epithelial cells and evading complement attack. We assessed the serological responses to BBK32 and OspE in 19 individuals diagnosed with neuroborreliosis to see whether antibodies that could both target the bacteria and neutralize the virulence mechanisms on the microbial surface emerge. Results evaluate levels of total protein, IgG and the chemokine CXCL13, a determinant for B-cell recruitment during neuroinflammation, in patients' cerebrospinal fluid samples. Antibody levels against BBK32 and OspE correlated with those against VlsE, a well-characterized diagnostic serological marker of the disease. A dual serological profile of the patients was observed. K-means clustering split the cohort into two discrete groups presenting distinct serological and CNS responses. One group contained young patients with low levels of anti-BBK32 and OspE antibodies. The other group showed stronger responses, possibly following prolonged infections or reinfections. Additionally, we assessed anti-ganglioside antibodies that could cause autoimmunity or complement dysregulation but observed that they did not correlate with neuroborreliosis in our patient cohort. The dual nature of antibody responses against the virulence factors BBK32 and OspE in neuroborreliosis patients may suggest the necessity of repeated exposures for efficient immune responses. Better protection could be achieved if the virulence factors were formulated into vaccines.

Identification of CXCL13 as a Promising Biomarker for Immune Checkpoint Blockade Therapy and PARP Inhibitor Therapy in Ovarian Cancer.

Ovarian cancer has poor response rates to immune checkpoint blockade (ICB) therapy, despite the use of genomic sequencing to identify molecular targets. Homologous recombination deficiency (HRD) is a conventional indicator of genomic instability (GI) and has been used as a marker for targeted therapies. Indicators reflecting HRD status have shown potential in predicting the efficacy of ICB treatment. Public databases, including TCGA, ICGC, and GEO, were used to obtain data. HRD scores, neoantigen load, and TMB were obtained from the TCGA cohort. Candidate biomarkers were validated in multiple databases, such as the Imvigor210 immunotherapy cohort and the open-source single-cell sequencing database. Immunohistochemistry was performed to further validate the results in independent cohorts. CXCL10, CXCL11, and CXCL13 were found to be significantly upregulated in HRD tumors and exhibited prognostic value. A comprehensive analysis of the tumor immune microenvironment (TIME) revealed that CXCL13 expression positively correlated with neoantigen load and immune cell infiltration. In addition, single-cell sequencing data and clinical trial results supported the utility of CXCL13 as a biomarker for ICB therapy. Not only does CXCL13 serve as a biomarker reflecting HRD status, but it also introduces a potentially novel perspective on prognostic biomarkers for ICB in ovarian cancer.

Constructing a prognostic model for colon cancer: insights from immunity-related genes.

BACKGROUND: Colon cancer (CC) is a malignancy associated with significant morbidity and mortality within the gastrointestinal tract. Recurrence and metastasis are the main factors affecting the prognosis of CC patients undergoing radical surgery; consequently, we attempted to determine the impact of immunity-related genes. RESULT: We constructed a CC risk model based on ZG16, MPC1, RBM47, SMOX, CPM and DNASE1L3. Consistently, we found that a significant association was found between the expression of most characteristic genes and tumor mutation burden (TMB), microsatellite instability (MSI) and neoantigen (NEO). Additionally, a notable decrease in RBM47 expression was observed in CC tissues compared with that in normal tissues. Moreover, RBM47 expression was correlated with clinicopathological characteristics and improved disease-free survival (DFS) and overall survival (OS) among patients with CC. Lastly, immunohistochemistry and co-immunofluorescence staining revealed a clear positive correlation between RBM47 and CXCL13 in mature tertiary lymphoid structures (TLS) region. CONCLUSION: We conclude that RBM47 was identified as a prognostic-related gene, which was of great significance to the prognosis evaluation of patients with CC and was correlated with CXCL13 in the TLS region.

Changes In Serum CXCL13 Levels Are Associated With Outcomes of Colorectal Cancer Patients Undergoing First-Line Oxaliplatin-Based Treatment.

Metastatic colorectal cancer (mCRC) currently lacks reliable biomarkers for precision medicine, particularly for chemotherapy-based treatments. This study examines the behavior of 11 CXC chemokines in the blood of 104 mCRC patients undergoing first-line oxaliplatin-based treatment to pinpoint predictive and prognostic markers. Serum samples were collected before treatment, at response evaluation (EVAR), and at disease progression or last follow-up. Chemokines were assessed in all samples using a Luminex® custom panel. CXCL13 levels increased at EVAR in responders, while in non-responders it decreased. Increasing levels of CXCL13 at EVAR, independently correlated with improved progression-free survival (PFS) and overall survival (OS). Nanostring® analysis in primary tumor samples showed CXCL13 gene expression's positive correlation not only with gene profiles related to an immunogenic tumor microenvironment, increased B cells and T cells (mainly CD8+) but also with extended OS. In silico analysis using RNAseq data from liver metastases treated or not with neoadjuvant oxaliplatin-based combinations, and deconvolution analysis using the MCP-counter algorithm, confirmed CXCL13 gene expression's association with increased immune infiltration, improved OS, and Tertiary Lymphoid Structures (TLSs) gene signatures, especially in neoadjuvant-treated patients. CXCL13 analysis in serum from 36 oxaliplatin-treated patients from the METIMMOX study control arm, reported similar findings. In conclusion, the increase of CXCL13 levels in peripheral blood and its association with the formation of TLSs within the metastatic lesions, emerges as a potential biomarker indicative of the therapeutic efficacy in mCRC patients undergoing oxaliplatin-based treatment.