Background The aim of this study was to evaluate the diagnostic performance of cerebrospinal fluid (CSF) free light chains (FLCs) in the diagnosis of Lyme neuroborreliosis (LNB). Methods Serum and CSF levels of κ- and λ-FLC, albumin and total concentration of immunoglobulin M (IgM) were determined together with CSF chemokine CXCL13 in 23 patients with definite LNB, 35 inflammatory neurological disease control (INDC) and 18 non-inflammatory control (NIC) patients. Indices and intrathecal fractions (IFs) of FLC and IgM were calculated. Results Significant differences in FLC indices and IFs were found between the LNB group and both control groups, p ≤ 0.007. Sensitivity of intrathecal κ- and λ-FLC synthesis reached 78%-87% in LNB patients with a specificity of 94%-100% in NIC patients, whereas specificity in INDC patients was 69%. The corresponding frequencies of positive results for IF and index of IgM and CSF CXCL13 in these three diagnostic groups were 74%-96% in LNB patients, 0% in NIC patients and 3%-6% in INDC patients at the chosen cut-off levels. Conclusions The findings of this study show a moderate to high sensitivity of CSF κ- and λ-FLC in LNB patients with a high specificity in NIC patients. However, overlap in CSF κ- and λ-FLC levels between LNB and INDC patients calls for caution in the interpretation and limits the diagnostic usefulness in the LNB diagnosis. CSF CXCL13 appears to be the most valuable additional biomarker of LNB aside from routine parameters such as CSF pleocytosis and anti-Borrelia antibody index.

Tertiary lymphoid organs (TLOs) frequently develop locally in adults in response to non-resolving inflammation. Chronic inflammation leads to the differentiation of stromal fibroblast cells toward lymphoid tissue organizer-like cells, which interact with lymphotoxin <mml:math><mml:msub><mml:mrow>α</mml:mrow><mml:mrow>1</mml:mrow></mml:msub><mml:msubsup><mml:mrow>β</mml:mrow><mml:mrow>2</mml:mrow><mml:mrow>+</mml:mrow></mml:msubsup></mml:math> immune cells. The interaction initiates lymphoid neogenesis by recruiting immune cells to the site of inflammation and ultimately leads to the formation of TLOs. Mature TLOs harbor a segregated T-cell zone, B-cell follicles with an activated germinal center, follicular dendritic cells, and high endothelial venules, which architecturally resemble those in secondary lymphoid organs. Since <em>CXCL13</em> and LTα₁β₂ play key roles in TLO neogenesis, they might constitute potential biomarkers of TLO activity. The well-developed TLOs actively regulate local immune responses and influence disease progression, and they are thereby regarded as the powerhouses of local immunity. In this review, we recapitulated the determinants for TLOs development, with great emphasis on the fundamental role of chronic inflammation and tissue-resident stromal cells for TLO neogenesis, hence offering guidance for therapeutic interventions in TLO-associated diseases.

Helicobacter pylori (H. pylori) is well-known to be involved in gastric carcinogenesis, associated with deregulation of cell proliferation and epigenetic changes in cancer-related genes. H. pylori infection is largely acquired during childhood, persisting long-term in about half of infected individuals, a subset of whom will go on to develop peptic ulcer disease and eventually gastric cancer, however, the sequence of events leading to disease is not completely understood. Knowledge on carcinogenesis and gastric damage-related biomarkers is abundant in adult populations, but scarce in children. We performed an extensive literature review focusing on gastric cancer related biomarkers identified in adult populations, which have been detected in children infected with H. pylori. Biomarkers were related to expression levels (RNA or protein) and/or methylation levels (DNA) in gastric tissue or blood of infected children as compared to non-infected controls. In this review, we identified 37 biomarkers of which 24 are over expressed, three are under expressed, and ten genes are significantly hypermethylated in H. pylori-infected children compared to healthy controls in at least 1 study. Only four of these biomarkers (pepsinogen I, pepsinogen II, gastrin, and SLC5A8) have been studied in asymptomatically infected children. Importantly, 13 of these biomarkers (β-catenin, C-MYC, GATA-4, DAPK1, CXCL13, DC-SIGN, TIMP3, EGFR, GRIN2B, PIM2, SLC5A8, CDH1, and VCAM-1.) are consistently deregulated in infected children and in adults with gastric cancer. Future studies should be designed to determine the clinical significance of these changes in infection-associated biomarkers in children and their persistence over time. The effect of eradication therapy over these biomarkers in children if proven significant, could lead to modifications in treatment guidelines for younger populations, and eventually promote the development of preventive strategies, such as vaccination, in the near future.

MicroRNAs (miRs) serve varying and important roles in the pathogenesis of non‑traumatic osteonecrosis (ON). However, the role miR‑186‑5p serves in the pathogenesis of osteonecrosis remains unknown and the clinical outcome of ON is still uncertain. The aim of the present study was to determine the expression characteristics, biological function and molecular mechanisms of miR‑186‑5p, which is associated with cancer development and progression, in osteoblastic differentiation and cell viability. The results of the present study showed that the expression levels of miR‑186‑5p were significantly higher in clinical non‑traumatic ON compared with osteoarthritis samples (P=0.0001). An inverse association was observed between miR‑186‑5p and CXCL13 expression levels. Furthermore, miR‑186‑5p inhibited phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT) signaling, downregulated osteoblast‑specific markers and reduced the viability and differentiation of human mesenchymal stem cells from bone marrow (HMSC‑bm) through targeting CXCL13. Increasing expression of CXCL13 in HMSC‑bm cells partially restored miR‑186‑5p‑mediated inhibition. In conclusion, abrogation of PI3K/AKT signaling triggered by miR‑186‑5p/CXCL13 may contribute to ON pathogenesis. These results highlight the possible clinical value of miR‑186‑5p in treatment for non‑traumatic ON.

In exceptional cases, patients with aseptic meningitis eventually develop aseptic meningoencephalitis. To find a candidate marker for the development of aseptic meningoencephalitis in adult patients diagnosed with aseptic meningitis, we compared 12 different cytokines/chemokines in cerebrospinal fluid (CSF) from 5 patients with aseptic meningoencephalitis, 8 patients with aseptic meningitis, and 8 patients with control disease. Only the CXCL13 concentration was significantly elevated in the CSF of the group with aseptic meningoencephalitis compared with the group with aseptic meningitis. Thus, CSF CXCL13 may be a useful marker for predicting the prognosis of aseptic meningitis.

The normal counterparts of peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) have not been accurately identified. We immunohistochemically analyzed 10 PTCL-NOS cases to examine the expression of the master regulators of T-cell differentiation and of surface antigens, including chemokine receptors. All cases were positive for the master regulator of helper T cells (Th-POK) and the marker of effector T cells (CD45RO). Three cases each were positive for T-Bet and GATA3, which are master regulators of helper T cells (T(H) ) type 1 (T(H)1) and 2 (T(H)2), respectively. Two cases were positive for the surface antigens of central memory (Tcm) (CCR7 and CD62L), and 1 case was positive for follicular helper T-cell (TFH) phenotype (BCL6, CXCL13, and PD-1). The remaining case was negative for all markers of effector T(H) subtypes. These results suggest the postulated normal counterparts of PTCL-NOS identified in 9 of the 10 cases consist of T(H)1, T(H)2, TCM, and TFH.

The follicular helper T cells (TFH) seemed to be expressed in several subsets of T-cell lymphomas. However, their expression in cutaneous T-cell lymphomas (CTCLs) has been rarely described. We investigated the clinical features, histopathological morphology, and expression of TFH markers in CTCLs. Forty-nine patients (24 men and 25 women) diagnosed with CTCL were examined, 25 patients with mycosis fungoides (MF) and 24 with other CTCLs. Immunohistochemical staining for CD10, Bcl-6, inducible costimulator, CXCL13, and PD-1 were performed. Relation between PD-1 and clinical course in MF was evaluated. PD-1 was detected in 21 of 25 (84.0%) MF cases and in 11 of 24 (45.8%) other CTCL cases. Bcl-6, CXCL13, inducible costimulator, and CD10 were occasionally expressed in most T-cell lymphomas, including MF. The staining for PD-1 was negative in all the MF cases with large-cell transformation. No correlation was observed between disease course and PD-1 expression rate in the MF cases. In conclusion, among the TFH markers, PD-1 was most frequently expressed in CTCL. PD-1 was expressed in most MF. PD-1 expression rates were significantly higher in MF than in other CTCLs.

Myasthenia gravis (MG) is a B cell-mediated and T cell-dependent autoimmune disease. Thymic hyperplasia has great significance for MG pathogenesis and treatment. MicroRNAs (miRNAs) are a newly recognized type of gene expression regulatory factor that regulate gene expression at the post-transcriptional level. Additionally, miRNAs are involved in immune regulation of the thymus and the occurrence and development of autoimmune diseases. In this study, we found 33 miRNAs that were significantly dysregulated in thymic tissues from MG patients with thymus hyperplasia (MGH) compared with thymic tissues from normal controls using a miRNA microarray chip. We found a negative correlation between the miR-548k and CXCL13 mRNA levels in a large set of samples using quantitative real-time polymerase chain reaction (qRT-PCR). We found that the CXCL13 3'-untranslated region (UTR) was a target of miR-548k using bioinformatics analysis. Next, we obtained direct evidence that CXCL13 is a target of miR-548k using a luciferase reporter assay. Finally, we demonstrated negative regulation between mir-548k and CXCL13 in Jurkat cells. Thus, miR-548k regulates the mRNA expression of its target gene CXCL13 in the thymus of MGH patients and plays an important role in MGH pathogenesis.

The spleen is comprised of spatially distinct compartments whose functions, such as immune responses and removal of aged red blood cells, are tightly controlled by the non-hematopoietic stromal cells that provide regionally-restricted signals to properly activate hematopoietic cells residing in each area. However, information regarding the ontogeny and relationships of the different stromal cell types remains limited. Here we have used in vivo lineage tracing analysis and in vitro mesenchymal stromal cell assays and found that Tlx1, a transcription factor essential for embryonic spleen organogenesis, marks neonatal stromal cells that are selectively localized in the spleen and retain mesenchymal progenitor potential to differentiate into mature follicular dendritic cells, fibroblastic reticular cells and marginal reticular cells. Furthermore, by establishing a novel three-dimensional cell culture system that enables maintenance of Tlx1-expressing cells in vitro, we discovered that signals from the lymphotoxin β receptor and TNF receptor promote differentiation of these cells to express MAdCAM-1, CCL19 and CXCL13, representative functional molecules expressed by different subsets of mature stromal cells in the spleen. Taken together, these findings indicate that mesenchymal progenitor cells expressing Tlx1 are a subset of lymphoid tissue organizer-like cells selectively found in the neonatal spleen.

Neolymphangiogenesis has recently been demonstrated in transplanted kidneys as well as in chronic interstitial nephritis and IgA nephropathy. However, its significance in kidney disease remains to be defined and a systematic study of renal lymphangiogenesis is warranted. We investigated patients with multiple myeloma (MM) presenting in the great majority with acute renal insufficiency. Controls were allograft kidney donors and patients with renal insufficiency due to acute renal failure (ARF). Lymph vessel length density (LVD) was quantified immunohistochemically by means of antipodoplanin staining followed by computer-assisted stereology. The mean LVD in kidneys of patients with MM (23.19 mm(-2)) was higher when compared with allograft donors (7.42 mm(-2), P = 0.0003) and patients with ARF (6.78 mm(-2), P = 0.0002). The higher LVD was significantly associated with interstitial inflammation, and the newly formed lymph vessels were accompanied by diffuse and nodular interstitial infiltrates composed mainly of CD20(+) B cells and CD27(+) plasma cells. The infiltrates in patients with MM also displayed a higher expression of the B-cell chemoattractant CXCL13. These results demonstrate for the first time that lymphangiogenesis is a prominent feature in MM kidneys and that it is associated with a significant accumulation of macrophages, CD20(+) and CD27(+) B lymphocytes. Further studies should clarify whether these changes represent a beneficial or detrimental factor in the progression of the myeloma-related kidney damage.

UNASSIGNED

To evaluate whether the anti-LINGO-1 antibody has immunomodulatory effects.

UNASSIGNED

Human peripheral blood mononuclear cells (hPBMCs), rat splenocytes, and rat CD4+ T cells were assessed to determine whether LINGO-1 was expressed and was inducible. Anti-LINGO-1 Li81 (0.1-30 μg/mL) effect on proliferation/cytokine production was assessed in purified rat CD4+ T cells and hPBMCs stimulated with antibodies to CD3 +/- CD28. In humans, the effect of 2 opicinumab (anti-LINGO-1/BIIB033; 30, 60, and 100 mg/kg) or placebo IV administrations was evaluated in RNA from blood and CSF samples taken before and after administration in phase 1 clinical trials; paired samples were assessed for differentially expressed genes by microarray. RNA from human CSF cell pellets was analyzed by quantitative real-time PCR for changes in transcripts representative of cell types, activation markers, and soluble proteins of the adaptive/innate immune systems. ELISA quantitated the levels of CXCL13 protein in human CSF supernatants.

UNASSIGNED

LINGO-1 is not expressed in hPBMCs, rat splenocytes, or rat CD4+ T cells; LINGO-1 blockade with Li81 did not affect T-cell proliferation or cytokine production from purified rat CD4+ T cells or hPBMCs. LINGO-1 blockade with opicinumab resulted in neither significant changes in immune system gene expression in blood and CSF, nor changes in CXCL13 CSF protein levels (clinical studies).

UNASSIGNED

These data support the hypothesis that LINGO-1 blockade does not affect immune function.

UNASSIGNED

This study provides Class II evidence that in patients with MS, opicinumab does not have immunomodulatory effects detected by changes in immune gene transcript expression.

Myasthenia gravis (MG) is an autoimmune neuromuscular disorder, affecting the quality of life of millions of people worldwide. The current study aims to determine the relationship between microRNA-143 (miR-143) and CXCL13, and whether it influences the pathogenesis of myasthenia gravis (MG). Thymus specimens were resected from patients with thymic hyperplasia combined MG, and then infused into normal mouse cavities to establish MG mice models. Immunohistochemistry, RT-qPCR, in situ hybridization detection, and Western blot analysis were employed to identify the expression of miR-143 and CXCL13 in MG and normal mice. The obtained thymocytes were cultured in vitro and transfected with a series of miR-143 mimic, miR-143 inhibitor, oe-CXCL13 or siRNA against CXCL13. MTT and flow cytometry assays were employed to assess cell viability, cycle entry, and apoptosis of the thymocytes. Dual luciferase reporter assay provided verification, confirming CXCL13 was the target gene of miR-143. Low miR-143 expression in the thymus tissues of the MG mice was detected, which presented with a reciprocal relationship with the expression rate of CLCX13. Observations in relation to the interactions between miR-143 mimic or siRNA CXCL13 exposure resulted in reduced cell viability, with a greater number of cells arrested at the G0/G1 phase, and a greater rate of induced apoptosis. Furthermore, overexpression of CXCL13 rescued miR-143 mimic-induced apoptosis. The findings have identified the potential role of miR-143 as a MG development mediator by targeting CXCL13. The key results obtained provide a promising experimental basis for the targeted intervention treatment of miR-143.

OBJECTIVE

The expression of cytokine-associated genes in dendritic cells (DCs) derived from umbilical cord blood (UCB) and adult peripheral blood (APB) was comprehensively compared in order to elucidate the difference in DC function between newborns and adults.

METHODS

Immature DCs were obtained from UCB and APB of healthy human donors. Several cytokines were added to generate mature DCs. Gene expression was compared using cDNA microarray containing 553 cytokine-associated genes. Eleven genes with differential expression were selected and determined their expression levels in DCs by quantitative real-time RT-PCR.

RESULTS

The expression of the Th1 response-related genes (IL-12B and IL-18) and chemokine genes (CXCL9, CXCL13, CCL18 and CCL24) was significantly lower in UCB-DCs than in APB-DC in both maturation states. On the other hand, calgranulins A and B, which are speculated to induce immune tolerance, showed higher expression in UCB-DCs. The expression of cell cycle-related genes (CDC2 and cyclin B1) was significantly higher in UCB-DCs than in APB-DCs, and immature UCB-DCs proliferated more rapidly than immature APB-DCs.

CONCLUSIONS

The expression of genes related to immune responses was significantly different between UCB- and APB-DCs, which may cause a decreased DC-mediated immunity and an increased susceptibility to infection in newborns.

Chemokine receptor CXCR5 is highly expressed in B-cells and under normal conditions is involved in their migration to specific areas of secondary lymphoid organs. B-cells are known to play an important role in various autoimmune diseases including multiple sclerosis (MS) where areas of demyelinating lesions attract B-cells by overexpressing CXCL13, the CXCR5 ligand. In this study, we aimed to determine the functional significance of single-nucleotide polymorphism rs630923 (A/C), which is located in cxcr5 gene promoter, and its common allele is associated with increased risk of MS. Using bioinformatics and pull-down assay in B-lymphoblastic cell lines, we showed that protective minor rs630923 "A" allele created functional binding site for MEF2C transcription factor. Elevated MEF2C expression in B-cells correlated with reduced activity of cxcr5 promoter containing rs630923 "A" allele. This effect that was fully neutralized by MEF2C-directed siRNA may mechanistically explain the protective role of the rs630923 minor allele in MS. Using site-directed mutagenesis of the cxcr5 gene promoter, we were unable to find any experimental evidence for the previously proposed role of NFκB transcription factors in rs630923-mediated CXCR5 promoter regulation. Thus, our results identify MEF2C as a possible mediator of protective function of the rs630923 "A" allele in MS.

BACKGROUND

The C-X-C motif chemokine ligand 13 (CXCL13) and its receptor CXCR5 play an important role in the homing of B-lymphocytes. As a biomarker in the cerebrospinal fluid (CSF), CXCL13 has increasingly been used for the diagnosis of neuroborreliosis (NB). We evaluated the diagnostic and prognostic potential of CXCL13 for NB and other neuroinflammatory diseases in an unselected cohort, paying attention to those patients particularly who might benefit from newly emerging CXCL13-directed therapies.

METHODS

We report the CSF CXCL13 concentrations and other relevant baseline characteristics for an unselected cohort of 459 patients. We compare different diagnostic groups and analyse the sensitivity and specificity of CSF CXCL13 as a marker of NB. The course of the CXCL13 concentrations is reported in a subgroup of 19 patients.

RESULTS

We confirm the high diagnostic yield of CXCL13 for NB in this unselected cohort. The optimal cut-off for the reliable diagnosis of NB was 93.83 pg/ml, resulting in a sensitivity and specificity of 95 and 97%, respectively (positive predictive value 55.9%, negative predictive value 99.8%), surpassing the sensitivity of both serological testing and PCR. CSF CXCL13 concentration showed a swift response to therapy. Non-NB patients with high CSF CXCL13 concentrations suffered from meningeosis neoplastica or infectious encephalitis.

CONCLUSIONS

CXCL13 is a valuable tool for the diagnosis and assessment of therapeutic response in NB. Furthermore, our data point towards an emerging role of CXCL13 in the diagnosis and prognosis of viral encephalitis and meningeosis neoplastica. These results are of particular interest in the light of recently developed approaches to CXCL13-directed therapeutic interventions.

Acute human immunodeficiency virus (HIV) infection is associated with a marked induction of several pathways that are linked to inflammation and CD4 T-cell depletion. Many of these processes do not fully resolve on short-term combination antiretroviral therapy (cART) (<5 years), despite complete and durable suppression of viremia. The effects of long-term (>15 years) successful antiretroviral therapy (ART) and the linkage between levels of biomarkers remain unclear. Therefore, the present study aims to assess the host plasma proteome in a well-defined clinical material from HIV-1-positive male patients on successful long-term ART (>15 years) and compared them with age-matched healthy controls and treatment-naïve male patients with viremia in a cross-sectional manner.Plasma samples were obtained from 3 categories of age-matched HIV-1-positive male patients on long-term successfully (ART, n = 10) with a median (Interquartile range, IQR) of 19 (17-20) years, treatment-naïve patients with viremia (VP, n = 14), and HIV-1-negative persons (HC, n = 11). Plasma proteome was analyzed using the proximity extension assay targeting 92 factors. Statistical analyses were performed with GraphPad Prism v7, R-packages, and Qlucore Omics Explorer v3.2. Functional enrichment analysis was performed by Kyoto Encyclopedia of Genes and Genomes (KEGG), and interactions of specific molecules were identified using Path Designer integrated into Ingenuity Pathway Analysis (IPA).Group wise comparison identified 53 soluble factors, which differed between the groups (P < .05). Cluster analysis identified 13 discrete soluble factors (CD8A, CRTAM, CXCL13, EGF, CD5, CD40, CXCL9, Gal-1, IL12RB1, KLRD1, PD-1, CASP-8 and TNFRSF9) between the studied groups (adjusted P < .001). The long-term successfully ART-treated individuals clustered and networked with the HC while VPs clustered separately. All of the proinflammatory cytokines and chemokines were normalized back to levels of healthy controls in long-term successfully ART-treated individuals, but not the levels of KLRD1 and PGDFB.sKLRD1 that is involved in the regulation of natural killer cell (NK) mediated cytotoxicity, failed to be restored to the level of HIV-negative individuals despite successful long-term ART. Additional analysis of NK cells along with T-cell subsets can provide insights into the long-term effects of ART on the immune system.

Early diagnosis and targeted therapy are crucial to mitigating the morbidity and mortality of oral squamous cell carcinoma. Among the potentially malignant oral disorders, epithelial dysplasia has known association with malignant transformation, but defensible gradation of dysplasia severity presents unmet challenges. Published microarray data has denoted dysregulation of CLSP, ELF3, IFI44, USP18, and CXCL13 genes in potentially malignant oral disorders. The present study investigated the diagnostic potential of these gene products to grade oral epithelial dysplasia severity. Archived biopsies from independent patient cohorts comprised "training" (n=107) and "test" (n=278) sample sets. Immunoreactivity for candidate markers was determined in the "training" set of normal oral mucosa (NOM), mild dysplasia (MD), moderate to severe dysplasia, and oral squamous cell carcinoma (OSCC). The diagnostic potential of ELF3 immunoscoring to improve detection and severity gradation of epithelial dysplasia was assessed with the "test" set. A reciprocal relationship between disease severity and immunoreactivity score for CLSP and ELF3 was observed (MD/NOM to OSCC: P<.08, Mann-Whitney U test), whereas elevated IFI44 immunostaining was present for OSCC compared to MD/NOM (P<.08, Mann-Whitney U test). Loss of ELF3 immunostaining effectively distinguished OSCC from non-malignant tissues (sensitivity=0.81; specificity=0.56; area under the curve [AUC]=0.68) but did not distinguish dysplasia from NOM (sensitivity=0.55; specificity=0.40; AUC=0.47) or moderate to severe dysplasia from MD (sensitivity=0.63; specificity=0.51; AUC=0.57). The results confirm via immunohistochemistry the relevance of published CLSP, ELF3, and IFI44 (but not USP18 or CXCL13) gene expression data to potentially malignant oral lesion severity. Loss of ELF3 immunostaining discriminated OSCC from dysplasia but was unreliable for grading dysplasia severity.

Low environmental temperatures have a profound effect on biological processes in the body, including the immune system. Cold exposure coincides with hormonal changes, which may directly or indirectly alter the immune system, even in the skeletal muscle. The aim of the present study was to investigate the effect of cold acclimation on immune composition in skeletal muscle. Skeletal muscle biopsies were obtained from 17 healthy lean subjects before and after 10 days of mild cold exposure (15 °: C, 6 h/day). Nonshivering thermogenesis was calculated by indirect calorimetry. We found that cold acclimation increased nonshivering thermogenesis from 10.8 ± 7.5 before to 17.8 ± 11.1% after cold acclimation (P < 0.01), but did not affect plasma catecholamine nor cytokine levels. In contrast, cold acclimation affected mRNA expression of several immune cell markers in skeletal muscle. It downregulated expression of the Th17 markers RORC (-28%, P < 0.01) and NEDD4L (-15%, P < 0.05), as well as the regulatory T-cell marker FOXP3 (-13%, P < 0.05). Furthermore, cold acclimation downregulated expression of the M2 macrophage markers CCL22 (-50%, P < 0.05), CXCL13 (-17%, P < 0.05) and CD209 (-15%, P < 0.05), while the M1 macrophage marker IL12B was upregulated (+141%, P < 0.05). Cold acclimation also enhanced several markers related to interferon (IFN) signaling, including TAP1 (+12%, P < 0.01), IFITM1/3 (+11%, P < 0.05), CD274 (+36%, P < 0.05) and STAT 2 (+10%, P < 0.05). In conclusion, 10 days of intermittent cold exposure induces marked changes in the expression of immune cell markers in skeletal muscle of healthy lean subjects. The physiological consequences and therapeutic relevance of these changes remain to be determined.

Fibroblast growth factor 2 (FGF2) and cyclic AMP (cAMP) play critical roles in controlling the differentiation of osteoblasts and mineralization of bone. We have previously reported that each of FGF2 and forskolin (FSK) alone increase transcription of the bone sialoprotein (BSP) gene, and that together (FGF/FSK) they upregulate BSP gene expression synergistically in rat osteoblast-like ROS 17/2.8 cells. However, other genes that are upregulated after stimulation by FGF2, FSK or FGF/FSK remain unclear. In the present study, we investigated candidate genes associated with mineralization after stimulation by FGF2, FSK and FGF/FSK in two kinds of osteoblast-like cells using microarray and real-time PCR. In ROS17/2.8 cells, FGF2 and FSK each increased the gene expression of c-FOS (7.2-fold and 10.7-fold, respectively). However, FGF/FSK did not induce c-FOS gene expression. FGF2 increased the expression of the dentin matrix protein 1 (DMP1, 129.8-fold) gene. In contrast, FGF/FSK increased the expression of the amphiregulin (AREG, 73-fold) gene maximally. In human osteoblast-like Saos2 cells, FGF2 increased the expression of the osteopontin (SPP1, 16.7-fold), interleukin-8 (IL8, 6.4-fold) and IL11 (4.8-fold) genes. FSK induced the expression of the IL6 (2.6-fold), IL11 (4.0-fold), chemokine ligand 13 (CXCL13, 2.8-fold) and bone morphogenetic protein 2 (BMP2, 2.5-fold) genes. These results suggest that FGF2 and FSK might be crucial regulators of mineralization and bone formation.

Resistance to schistosomiasis is associated with increased levels of serum parasite-specific IgE. IgE exerts its functions through its cellular receptors, FcεRI and FcεRII/CD23; however, its functional significance in humans requires further characterization. We previously reported that increased levels of CD23(+) B cells correlate with resistance to schistosomiasis in hyperexposed populations and sought to define their potential function and relationship with IgE. We found that CD23(+) B cells are a heterogeneous cell population with functional and phenotypic differences. Circulating CD23(+) B cells are uniquely activated in schistosomiasis and express the CD23b isoform and CXCR5, the homing receptor for lymphoid follicles. High CXCR5 expression by CD23(+) B cells was associated with the capacity to home to the cognate ligand CXCL13. CD23-bound IgE cross-linking increased surface expression of CXCR5, suggesting that CD23(+) B cells home directly into the lymphoid follicles upon antigen capture. As human schistosomiasis is an intravascular parasitic infection associated with a high antigenic burden in the blood, circulating CD23(+) B cells may play a role in the capture and shuttling of antigens directly to splenic follicles, highlighting a new role for circulating B cells. This function likely plays an important role in the development of protective immunity to infection with schistosomes.