Molecular cloning and characterization of a novel human CC chemokine, SCYA26

CCL26 in primary biliary cholangitis - Is it a novel disease mediator?

AIM

To verify the role of CX3C chemokine ligand 1 - CX3C chemokine receptor 1 (CX3CL1-CX3CR1) pathway in the pathogenesis of primary biliary cholangitis (PBC). To explore whether CCL26, a novel functional ligand to CX3CR1, participates in the immunological mechanism of PBC.

METHODS

Fifty-nine PBC patients and 54 healthy controls were recruited. Enzyme-linked immunosorbent assay and flow cytometry were used to measure CX3CL1 and CCL26 concentrations in plasma and CX3CR1 expression on peripheral lymphocytes, respectively. Chemotactic effects of CX3CL1 and CCL26 toward lymphocytes were detected by Transwell cell migration assays. CX3CL1 and CCL26 expressions in liver were assessed by immunohistochemical staining. Effects of CX3CL1 and CCL26 on stimulating cytokine production from lymphocytes were evaluated using intracellular flow cytometry.

RESULTS

Significantly elevated CX3CL1 and CCL26 plasma concentration and CX3CR1 expression on CD4⁺ and CD8⁺ T cells were noted in PBC patients. CX3CL1 exhibited chemotactic activity toward CD8⁺ T, natural killer (NK) and NKT cells in a dose-dependent manner while such chemotactic effects were not detected for CCL26. In PBC patients, CX3CL1 and CCL26 were both increasingly expressed in biliary tracts and a concentration gradient of CCL26 in hepatocytes around portal areas was observed. Immobilized CX3CL1 could enhance interferon-γ production from T and NK cells while such effect was not exhibited by soluble CX3CL1 or CCL26.

CONCLUSIONS

CCL26 expression is significantly elevated in plasma and biliary duct of PBC patients, yet does not appear to attract CX3CR1-expressing immune cells. CX3CL1-CX3CR1 pathway promotes the infiltration of T, NK and NKT cells into bile ducts and forms a positive feedback loop with T-helper 1 type cytokines in PBC.

CCL26 Participates in the PRL-3-Induced Promotion of Colorectal Cancer Invasion by Stimulating Tumor-Associated Macrophage Infiltration

Both phosphatase of regenerating liver-3 (PRL-3) and tumor-associated macrophages (TAM) influence cancer progression. Whether PRL-3 plays a critical role in colorectal cancer invasion and metastasis by inducing TAM infiltration remains unclear. In the current study, we investigated the effects of chemokine ligand 26 (CCL26) on TAM infiltration and colorectal cancer invasion and the underlying mechanism in colorectal cancer cells by overexpressing or silencing PRL-3. We found that PRL-3 upregulated CCL26 expression correlatively and participated in cell migration, according to the results of gene ontology analysis. In addition, IHC analysis results indicated that the PRL-3 and CCL26 levels were positively correlated and elevated in stage III and IV colorectal cancer tissues and were associated with a worse prognosis in colorectal cancer patients. Furthermore, we demonstrated that CCL26 induced TAM infiltration by CCL26 binding to the CCR3 receptor. When LoVo-P and HT29-C cells were cocultured with TAMs, CCL26 binding to the CCR3 receptor enhanced the invasiveness of LoVo-P and HT29-C cells by mobilizing intracellular Ca²⁺of TAMs to increase the expression of IL6 and IL8. In addition, IHC results indicated that protein levels of CCR3 and TAMs counts were higher in stage III and IV colorectal cancer tissues and correlated with CCL26. Moreover, similar results were observed in vivo using mice injected with LoVo-P and HT29-C cells. These data indicate that PRL-3 may represent a potential prognostic marker that promotes colorectal cancer invasion and metastasis by upregulating CCL26 to induce TAM infiltration. Mol Cancer Ther; 17(1); 276-89. ©2017 AACR.

Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcus Immunology: A Pilot Study

OBJECTIVE

To elucidate specific cytokine and chemokine markers in patients diagnosed with pediatric autoimmune neuropsychiatric disorder associated with streptococcus (PANDAS).

STUDY DESIGN

Prospective cohort study.

STUDY SETTING

Academic university hospital.

METHODS

Tonsil tissue was collected from 24 patients and organized into 3 groups: experimental PANDAS cohort (12 patients), group A beta hemolytic streptococcus control cohort (6 patients), and obstructive sleep apnea control cohort (6 patients). Each tissue sample was extracted with MSD Tris lysis buffer, and protein lysates were analyzed for human chemokines and cytokines by the Human Cytokine 30-Plex Assay on the Mesoscale System.

RESULTS

We identified a significant difference in expression regarding the 8 following cytokines when comparing the experimental PANDAS, group A beta hemolytic streptococcus, and obstructive sleep apnea control cohorts: tumor necrosis factor-α and eotaxin-3. In addition, our group also identified a significant reduction in the expression of interleukin (IL)-8, interferon inducible protein-10, IL-17a, interferon-γ, IL-10, and IL-12 across the aforementioned groups.

CONCLUSIONS

Patients diagnosed with PANDAS appear to maintain significantly different concentrations of cytokines when compared with patients afflicted by chronic group A beta hemolytic streptococcus infections and obstructive sleep apnea. As a result, one could potentially use the described characterization of immunologic markers as a basis for future mechanistic and epidemiological studies.

Immune markers in breast milk and fetal and maternal body fluids: a systematic review of perinatal concentrations

Breastfeeding represents the continued exposure of the infant to the maternal immune environment.Uterine, perinatal, and postnatal exposure to immune factors may contribute to an infant’s risk of developing immune-mediated disorders, including allergies. A PubMed search was conducted to review studies in humans and analyze concentrations of immune markers (TGF-beta, IFN-gamma, eotaxin, CCL5, CXCL10, TNF-alpha, MCP-1, IL-1beta, IL-4, IL-5, IL-6,IL-8, IL-10, IL-12, IL-13, sCD14, sIgA, IgG4, IgM) found in maternal serum, amniotic fluid, cord serum, colostrum, transition and mature milk. Concentrations of immune markers showed large variations across samples and studies. Reports documented conflicting results. Small sample sizes, differences in population characteristics, inconsistent sample collection times, and various sample collection and measurement methods may have led to wide variations in the concentrations of immune markers. Studies analyzing the associations between immune markers in maternal fluids and infant allergies remain inconclusive because of gaps in knowledge and a lack of standardized methods.

Effect and mechanism of lipopolysaccharide on allergen-induced interleukin-5 and eotaxins production by whole blood cultures of atopic asthmatics

Interleukin (IL)-5 and eotaxin families regulate the development of eosinophilic inflammation of asthma in a co-operative manner. The exposure to airborne lipopolysaccharide (LPS) induces varying degrees of airflow obstruction and neutrophilic airway inflammation. Production of IL-5 and eotaxin subfamily chemokines was analysed in response to Dermatophagoides pteronyssinus allergen (D.p.) according to the presence of specific IgE to D.p., and investigated the mechanism underlying their LPS-mediated regulation of these cytokines in response to the specific allergen. Peripheral blood cells (PBCs) from asthmatics with (group 1) or without (group 2) specific IgE to D.p. and from non-asthmatics with (group 3) or without (group 4) were stimulated with D.p. or LPS. For LPS-mediated inhibition of IL-5 and eotaxin-2 production, LPS-induced cytokines were added to the D.p.-stimulated PBCs. IL-5 and eotaxin-2, but not eotaxin-1 and 3, were significantly increased by D.p.-stimulated-PBCs from group 1, while only eotaxin-2 was elevated in group 3. Eotaxin-2 production was found in monocytes and correlated with the level of specific IgE to D.p. LPS treatment resulted in the decrease in eotaxin-2 and IL-5 production by the D.p.-stimulated PBCs. LPS-induced IL-10 completely inhibited D.p.-stimulated production of eotaxin-2 and IL-5. The differential responses of the eotaxin family to specific antigens suggest that the predominant role of eotaxin-2 and LPS may attenuate eosinophilic inflammation by inhibiting IL-5 and eotaxin-2 synthesis through IL-10 production.

Comparison of plasma eotaxin family level in aspirin-induced and aspirin-tolerant asthma patients

STUDY OBJECTIVE

Eosinophilic infiltration of airway tissue is a central feature of aspirin-induced asthma (AIA). Eotaxins belong to the family of CC chemokines, which coordinate the recruitment of inflammatory cells bearing chemokine (C-C motif) receptor-3 to sites of allergic inflammation. In the present study, the levels of eotaxin-1, eotaxin-2, and eotaxin-3 following an oral aspirin provocation test (APT) were measured, and the relationship between the eotaxin level and clinical parameters in patients with asthma was evaluated.

PATIENTS AND DESIGN

An APT was performed in patients with asthma. Twenty AIA patients and 23 aspirin-tolerant asthma (ATA) patients were identified. Plasma levels of eotaxin-1, eotaxin-2, and eotaxin-3 levels were measured by enzyme-linked immunosorbent assay in the 43 patients with asthma and in 39 control subjects.

RESULTS

The proportion of blood eosinophils was significantly higher in asthmatic patients than in control subjects. Nasal polyps were more common in AIA patients than in ATA patients (p < 0.05). In addition, the eotaxin-1 level was higher in AIA and ATA patients than in control subjects (p < 0.01 for each). The eotaxin-2 level was higher in ATA patients than in either the AIA patients (p < 0.05) or control subjects (p < 0.01). Similarly, the eotaxin-3 level was higher in ATA patients than in control subjects. A trend toward higher plasma levels of eotaxin-1 and eotaxin-3 at baseline and at 4 h after APT administration in the ATA group was noted but was not significant. Eotaxin-2 was also higher in ATA patients than in AIA patients at baseline and at 4 h after the APT.

CONCLUSION

This study shows that eotaxin-2 is differentially secreted in patients with asthma according to aspirin intolerance, and that secretion is not time-dependent in response to the APT in AIA and ATA patients. It therefore appears that eotaxin-2 may be up-regulated and may act differentially in patients with ATA.

Association of eotaxin-2 gene polymorphisms with plasma eotaxin-2 concentration

Chemokine (C-C motif) ligand 24 (CCL24, eotaxin-2) is a CC chemokine that recruits and activates cells bearing the CC chemokine receptor 3, which play a major role in asthma. Previously, we observed a significant association between a single nucleotide polymorphism (SNP) in eotaxin-2 (CCL24+1272A--> G) and a lower risk of asthma. Consequently, this study has followed up on those genetic effects by evaluating the association between the SNP and plasma eotaxin-2 concentration in 172 asthmatics and 135 normal controls. Asthmatics had significantly higher plasma eotaxin-2 levels than did normal controls (P=0.02). The SNP (CCL24+1272A--> G) and two haplotypes (ht2 and ht6) were strongly associated with plasma eotaxin-2 levels in asthmatics (CCL24+1272A--> G: P=0.006, ht2: P=0.006, and ht6: P=0.002). The CCL24+1272A--> G allele and the ht2 and ht6 haplotypes showed a gene-dose effect on the plasma eotaxin-2 levels in asthmatics (P=0.005-0.032). In conclusion, the susceptibility of patients with asthma to high eotaxin-2 production may be due to genetic effects of the CCL24+1272A--> G polymorphism, ht2 and ht6 haplotypes.

Upregulation of Interleukin-4 Receptor by Interferon-γ

Airway epithelial cells produce a number of chemokines, including eotaxins. Among the three known eotaxins, T helper (Th) type 2 cytokines have been observed to induce the expression of eotaxin-3 mRNA. This study investigated the effect of interferon (IFN)-gamma, a Th1 cytokine, on Th2 cytokine-induced eotaxin-3 production in a bronchial epithelial cell line, BEAS-2B. BEAS-2B cells produced eotaxin-3 after stimulation with the Th2 cytokines interleukin (IL)-13 and IL-4. When BEAS-2B cells were cultured with varying concentrations of IFN-gamma for 24 h, dose-dependent inhibition of Th2 cytokine-induced eotaxin-3 mRNA expression and protein production was observed. This was associated with downregulation of signal transducer and activator of transcription 6 activation. On the other hand, 2-d pretreatment of BEAS-2B cells with IFN-gamma dose-dependently enhanced Th2 cytokine-induced eotaxin-3 mRNA expression and production. IFN-gamma also increased the mRNA expression and protein production of IL-4 receptor (R) alpha in a time- and dose-dependent manner. In addition, IL-2Rgamma, a component of the type 1 IL-4R, was also upregulated by IFN-gamma. These results indicate that IFN-gamma has opposite effects on Th2 cytokine-induced eotaxin-3 production in BEAS-2B cells, depending on the length of exposure. Because high levels of IFN-gamma are produced during viral infection, airway viral infection may affect allergic airway inflammation in vivo by modulation of eotaxin-3 production.

Neutrophil C5a receptor and the outcome in a rat model of sepsis

Complement fragment 5a (C5a)-C5a receptor (C5aR) signaling plays an essential role in neutrophil innate immunity. Blockade of either the ligand or the receptor improves survival rates in experimental sepsis. In the current study, sepsis was induced in rats by cecal ligation/puncture. Early in sepsis C5aR content on neutrophils significantly dropped, reached the nadir at 24 h after onset of sepsis, and progressively elevated thereafter. Western-blot, RT-PCR, and confocal microscopy analyses revealed that the loss and re-expression of C5aR during sepsis might be due, at least in part, to the receptor internalization and reconstitution. The reduction and reconstitution of C5aR correlate with the loss and restoration of innate immune functions of blood neutrophils (chemotaxis and reactive oxygen species production), respectively. Quantitative measurements of C5aR on blood neutrophils are highly predictive of survival or death during sepsis. These data suggest that neutrophil C5aR content represents an essential component of an efficient defense system in sepsis and may serve as a prognostic marker for the outcome.