RANTES induces nasal mucosal inflammation rich in eosinophils, basophils, and lymphocytes in vivo

Interleukin-19 enhances eosinophil infiltration through upregulation of epithelium-derived RANTES expression via the ERK/NF-κB signalling pathway in patients with eosinophilic CRSwNP

BACKGROUD

The recurrence rate of chronic rhinosinusitis with nasal polyps (CRSwNP) is positively correlated with eosinophil infiltration. Increased interleukin (IL)-19 and eosinophil chemokine RANTES levels have been reported in patients with CRSwNP. This study aimed to clarify the role of IL-19 in mediating RANTES expression and eosinophilic infiltration in eosinophilic CRSwNP (Eos CRSwNP).

METHODS

Nasal tissue samples were obtained from patients with CRSwNP and controls. The expression of IL-19, its receptors, ECP, and RANTES in tissues was investigated. Primary human nasal epithelial cells (HNECs) and nasal polyp tissue blocks were cultured, then stimulated by IL-19; ERK phosphorylation, NF-κB pathway activation, RANTES level, eosinophils migration and infiltration were detected using RT-qPCR, ELISA, western blotting, HE, immunohistochemistry, immunofluorescence staining, confocal microscopy, and transwell migration assay.

RESULTS

The expression of IL-19 and its receptors (IL-20R1/IL-20R2), eosinophil cationic protein, and RANTES in nasal tissues from patients with Eos CRSwNP was significantly increased compared to that in non-Eos CRSwNP and control subjects. IL-19 co-localized with RANTES in nasal tissues and significantly elevated RANTES expression in HNECs. IL-19-blocking antibody and siRNA knockdown of IL-20R1 ameliorated the effect of IL-19 on RANTES secretion in HNECs. Moreover, IL-19-induced RANTES upregulation was associated with the activation of the ERK and NF-κB pathways. NF-κB activation was mediated by the ERK pathway in IL-19-treated HNECs, and IL-19 enhanced eosinophil infiltration in nasal polyp tissue blocks.

CONCLUSIONS

Our findings indicate that IL-19 promotes RANTES expression via the ERK/NF-κB pathway in HNECs and is implicated in eosinophil infiltration in patients with Eos CRSwNP.

Immune Cells in the Spleen of Mice Mediate the Inflammatory Response Induced by Mannheimia haemolytica A2 Serotype

(1) Background: Mannheimia haemolytica (M. haemolytica) is an opportunistic pathogen and is mainly associated with respiratory diseases in cattle, sheep, and goats. (2) Methods: In this study, a mouse infection model was established using a M. haemolytica strain isolated from goats. Histopathological observations were conducted on various organs of the mice, and bacterial load determination and RNA-seq analysis were specifically performed on the spleens of the mice. (3) Results: The findings of this study suggest that chemokines, potentially present in the spleen of mice following a M. haemolytica challenge, may induce the migration of leukocytes to the spleen and suppress the release of pro-inflammatory factors through a negative feedback regulation mechanism. Additionally, an interesting observation was made regarding the potential of hematopoietic stem/progenitor cells congregating in the spleen to differentiate into immune cells, which could potentially collaborate with leukocytes in their efforts to counteract M. haemolytica invasion. (4) Conclusions: This study revealed the immune regulation mechanism induced by M. haemolytica in the mouse spleen, providing valuable insights into host-pathogen interactions and offering a theoretical basis for the prevention, control, and treatment of mannheimiosis.

Osteoid cell-derived chemokines drive bone-metastatic prostate cancer

One of the greatest challenges in improving prostate cancer (PCa) survival is in designing new therapies to effectively target bone metastases. PCa regulation of the bone environment has been well characterized; however, bone-targeted therapies have little impact on patient survival, demonstrating a need for understanding the complexities of the tumor-bone environment. Many factors contribute to creating a favorable microenvironment for prostate tumors in bone, including cell signaling proteins produced by osteoid cells. Specifically, there has been extensive evidence from both past and recent studies that emphasize the importance of chemokine signaling in promoting PCa progression in the bone environment. Chemokine-focused strategies present promising therapeutic options for treating bone metastasis. These signaling pathways are complex, with many being produced by (and exerting effects on) a plethora of different cell types, including stromal and tumor cells of the prostate tumor-bone microenvironment. ​This review highlights an underappreciated molecular family that should be interrogated for treatment of bone metastatic prostate cancer (BM-PCa).

Cell-Type Specific Expression of Hyaluronan Synthases HAS2 and HAS3 Promotes Goblet Cell Hyperplasia in Allergic Airway Inflammation

Allergic rhinitis (AR) is a multifactorial airway disease characterized by basal and goblet cell hyperplasia. Hyaluronic acid (HA) is a major component of extracellular matrix and a critical contributor to tissue repair and remodeling after injury. We previously demonstrated that the intermediate progenitor cell (IPC) surface marker CD44v3 is upregulated in the basal and suprabasal layers of well-differentiated primary human nasal epithelial (HNE) cells after stimulation with the Th2 cytokine interleukin (IL)-4, and an antibody blocking the CD44v3-HA interaction suppressed IL-4-induced goblet cell hyperplasia. We now show that the expression of HA and two HA synthases, HAS2 and HAS3, was upregulated in both the nasal surface epithelium of subjects with AR and IL-4-stimulated HNE cells. Inhibition of HA synthesis by 4-methylumbelliferone (4-MU) suppressed IL-4-induced goblet cell hyperplasia. Moreover, HAS2 and HAS3 were expressed in IPCs depending on the differentiation events, as follows: the rapid, transient upregulation of HAS2 induced basal IPC proliferation and basal-to-suprabasal transition, whereas the delayed upregulation of HAS3 promoted the transition of suprabasal IPCs to a goblet cell fate. 4-MU treatment in house dust mite-induced murine AR model attenuated goblet cell metaplasia. Lastly, HA levels in nasal epithelial lining fluids from AR patients positively correlated with the levels of mediators causing allergic inflammation. These data suggest that HA produced following the sequential upregulation of HAS2 and HAS3 contributes to goblet cell hyperplasia in allergic airway inflammation and modulates disease progression.

Comprehensive Analysis of Nasal Polyps Reveals a More Pronounced Type 2 Transcriptomic Profile of Epithelial Cells and Mast Cells in Aspirin-Exacerbated Respiratory Disease

Chronic rhinosinusitis with nasal polyps is affecting up to 3% of Western populations. About 10% of patients with nasal polyps also suffer from asthma and intolerance to aspirin, a syndrome called aspirin-exacerbated respiratory disease. Although eosinophilic inflammation is predominant in polyps of both diseases, phenotypic differences in the tissue-derived microenvironment, elucidating disease-specific characteristics, have not yet been identified. We sought to obtain detailed information about phenotypic and transcriptional differences in epithelial and immune cells in polyps of aspirin-tolerant and intolerant patients. Cytokine profiles in nasal secretions and serum of patients suffering from aspirin-exacerbated respiratory disease (n = 10) or chronic rhinosinusitis with nasal polyps (n = 9) were assessed using a multiplex mesoscale discovery assay. After enrichment for immune cell subsets by flow cytometry, we performed transcriptomic profiling by employing single-cell RNA sequencing. Aspirin-intolerant patients displayed significantly elevated IL-5 and CCL17 levels in nasal secretions corresponding to a more pronounced eosinophilic type 2 inflammation. Transcriptomic profiling revealed that epithelial and mast cells not only complement one another in terms of gene expression associated with the 15-lipoxygenase pathway but also show a clear type 2-associated inflammatory phenotype as identified by the upregulation of POSTN, CCL26, and IL13 in patients with aspirin-exacerbated respiratory disease. Interestingly, we also observed cellular stress responses indicated by an increase of MTRNR2L12, MTRNR2L8, and NEAT1 across all immune cell subsets in this disease entity. In conclusion, our findings support the hypothesis that epithelial and mast cells act in concert as potential drivers of the pathogenesis of the aspirin-exacerbated respiratory disease.

Therapeutic Effect of C-C Chemokine Receptor Type 1 (CCR1) Antagonist BX471 on Allergic Rhinitis

Objective and Design

Allergic rhinitis (AR) is an immunoglobulin E (IgE)-mediated inflammatory respiratory hypersensitivity characterized by elevated Th2 cytokines and infiltration of inflammatory cells to nasal tissues. BX471 is a small-molecule C-C chemokine receptor type 1 (CCR1) antagonist involved in suppression of inflammation via blocking of primary ligands. In this study, we examined the anti-inflammatory effect of BX471 on ovalbumin (OVA)-induced AR mice model.

Materials and Methods

Levels of OVA-specific IgE and Th1 cytokines were determined by enzyme-linked immunosorbent assay (ELISA). Nasal expression of proinflammatory mediators was assessed by real-time polymerase chain reaction (RT-qPCR). Nasal-cavity sections were stained with hematoxylin and eosin (HE) and periodic acid-Schiff (PAS) to study eosinophil infiltration and goblet cell metaplasia. Relative protein levels of Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-kB), Toll-like Receptor 4 (TLR4) and Toll-like-receptor 2 (TLR2) were assessed by Western Blot. Percentage of CD4⁺CD25⁺Foxp3⁺ T regulatory cells (Treg) was measured by flow cytometry.

Results

Mice treated with BX471 showed significantly relieved sneezing and nasal-rubbing behaviors. The expression of nasal proinflammatory factors was significantly downregulated by BX471, and protein levels of tumor necrosis factor alpha (TNF- α) and NF-kB were suppressed. Blockade of CCR1 ligands inhibited eosinophil recruitment in nasal cavity. In addition, Treg cells population were upregulated in BX471-treated mice.

Conclusion

BX471 exerts anti-inflammatory effects in a mouse model of AR by inhibiting CCR1-mediated TNF-α production, which subsequently suppresses NF-kB activation in inflammatory cells, leading to a decrease in Th2 cytokines, IL-1β, VCAM-1, GM-CSF, RANTES, and MIP-1α expression levels, thus inhibiting eosinophil recruitment to nasal mucosa. In addition, BX-471 exhibits anti-allergic effect by increasing Treg cell population. Overall, BX471 represents a promising therapeutic strategy against AR.

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The impact of allergen exposure and specific immunotherapy on circulating blood cells in allergic rhinitis

Allergic rhinitis (AR) is an IgE-mediated inflammatory disease of the nasal mucosa with well described local immune responses during allergen exposure. The frequent association of AR with general extra-nasal symptoms and other allergic conditions, such as conjunctivitis and asthma, however, support a more systemic disease impact. In addition to acute elevation of soluble inflammatory mediators in periphery blood, a growing number of studies have reported changes in circulating blood cells after specific nasal allergen challenge or environmental allergen exposure. These findings imply an involvement of specific blood leukocyte subsets, thrombocytes and recently, erythrocytes. This review summarizes the circulating blood cell dynamics associated with allergen exposure in AR subjects reported so far. Additionally, the impact of therapy, particularly allergen-specific immunotherapy (AIT), the only currently available causal treatment reducing AR-related symptoms, is further considered in this context.

The Role of RANTES in Nasal Polyposis

Background

Characteristic infiltrates of eosinophils are a hallmark of nasal polyps (NPs). Several studies suggest that members of the CC chemokine family may be involved in this process. RANTES (regulated on activation, normal t-cell-expressed and secreted) is a member of the CC chemokine family with chemotactic activity on mainly eosinophils and T lymphocytes. Thus, RANTES is an interesting target for the recruitment of eosinophils and T lymphocytes into the nose. The degree of the tissue eosinophilia has been reported to correlate with the severeness of the symptomatology of the disease and the extension on the lower respiratory tract, as well as with the probability of the recurrence of NPs. Therefore, we hypothesized that high numbers of eosinophils correlate with high levels of RANTES and that associated atopic diseases modify this correlation.

Methods

Total RNA was extracted from NP homogenates, reverse transcribed and RANTES mRNA expression analyzed using semiquantitative reverse transcription polymerase chain reaction and Northern blot analysis. Histological studies divided NPs in an eosinophilic and low eosinophilic group. Additionally, RANTES protein concentration was measured in homogenates by a RANTES-specific enzyme-linked immunosorbent assay.

Results

This study has clearly shown that RANTES is expressed and secreted in NPs. The group with a high tissue eosinophilia had a significant higher RANTES gene expression and protein production than NPs without tissue eosinophilia. The isolated coincidence of acetylsalicyl acid intolerance with chronic hyperplastic sinusitis/NP additionally increased significantly the RANTES amounts in NPs.

Conclusion

Increased RANTES leads to increased tissue eosinophilia. Associated acetylsalicylic acid intolerance seems to enhance the amount of RANTES in NPs and might explain in part the more severe clinical course in those patients. Thus, RANTES appears to play an important role in mobilization of eosinophils into the local inflamed tissue.

O-GalNAcylation of RANTES Improves Its Properties as a Human Immunodeficiency Virus Type 1 Entry Inhibitor

Many human proteins have the potential to be developed as therapeutic agents. However, side effects caused by direct administration of natural proteins have significantly slowed expansion of protein therapeutics into the clinic. Post-translational modifications (PTMs) can improve protein properties, but because of significant knowledge gaps, we are considerably limited in our ability to apply PTMs to generate better protein therapeutics. Here, we seek to fill the gaps by studying the PTMs of a small representative chemotactic cytokine, RANTES. RANTES can inhibit HIV-1 infection by competing with it for binding to receptor CCR5 and stimulating CCR5 endocytosis. Unfortunately, RANTES can induce strong signaling, leading to severe inflammatory side effects. We apply a chemical biology approach to explore the potential of post-translationally modified RANTES as safe inhibitors of HIV-1 infection. We synthesized and systematically tested a library of RANTES isoforms for their ability to inhibit inflammatory signaling and prevent HIV-1 infection of primary human cells. Through this research, we revealed that most of the glycosylated variants have decreased inflammation-associated properties and identified one particular glyco variant, a truncated RANTES containing a Galβ1-3GalNAc disaccharide α-linked to Ser4, which stands out as having the best overall properties: relatively high HIV-1 inhibition potency but also weak inflammatory properties. Moreover, our results provided a structural basis for the observed changes in the properties of RANTES. Taken together, this work highlights the potential importance of glycosylation as an alternative strategy for developing CCR5 inhibitors to treat HIV-1 infection and, more generally, for reducing or eliminating unwanted properties of therapeutic proteins.

Differences in RANTES and IL-6 levels among chronic rhinosinusitis patients with predominant gram-negative and gram-positive infection

Background

Bacteria are suspected players in the pathogenesis of chronic rhinosinusitis (CRS), yet their exact role is not understood. We investigated the effect of planktonic and biofilm of staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA) on the mucosa of CRS patients with gram-positive and gram-negative infections by measuring the levels of IL-6 and RANTES, a chemokine with activity on eosinophils and T lymphocytes.

Methods

Ethmoid mucosa of six CRS patients with gram-positive bacteria on culture and five with gram-negative bacteria were compared to ethmoid mucosa of 8 control patients. The tissue explants were stimulated with SA and PA extracts in planktonic and biofilm form for 6 hours, then RANTES levels were measured by ELISA.

Results

Compared to the control group, CRS patients with gram-negative predominance demonstrated a significantly higher level of RANTES expression in response to all forms of bacterial stimuli (P-value <0.05). Patients with gram-positive predominance showed a higher level of RANTES compere to control group, however, this difference was not significant (P-value >0.05).

Conclusions

The mucosa of CRS patients with gram-negative infections has a heightened innate immune response compared to controls and patients with gram-positive infections. It is possible that this response leads to the pathological eosinophilic inflammation seen in CRS.

Electronic supplementary material

The online version of this article (doi:10.1186/s40463-016-0183-x) contains supplementary material, which is available to authorized users.

Potential Role of Chemokines in Fracture Repair

Chemokines are a family of small cytokines that share a typical key structure that is stabilized by disulfide bonds between the cysteine residues at the NH₂-terminal of the protein, and they are secreted by a great variety of cells in several different conditions. Their function is directly dependent on their interactions with their receptors. Chemokines are involved in cell maturation and differentiation, infection, autoimmunity, cancer, and, in general, in any situation where immune components are involved. However, their role in postfracture inflammation and fracture healing is not yet well established. In this article, we will discuss the response of chemokines to bone fracture and their potential roles in postfracture inflammation and healing based on data from our studies and from other previously published studies.

Gene expression analysis during recovery process indicates the mechanism for innate immune injury and repair from Coxsackievirus B3-induced myocarditis

To investigate the innate immune injury and repair mechanism during recovery from Coxsackievirus B3 (CVB3) induced myocarditis, we established an acute viral myocarditis recovery model by infecting BALB/c mice with CVB3. Histopathological examination of cardiac tissues after infection showed a gradual increase of myocardial injury to the maximum degree at 8 dpi (days post infection), followed by a recovery process with reduced viral replication. We also measured expression changes of innate immune genes in heart after 4, 8 and 12 days of infection using innate immune real-time PCR array. The results showed expression alterations in many Pattern Recognition Receptors (PRRs) genes upon CVB3 infection, which activated multiple important signaling pathways during recovery process. The expression of TLRs, RLRs, PKR and cytokines were strongly induced and reached the peak at 4 dpi in early myocarditis stage, followed by a gradual reduction in recovery stage, during which the levels were even lower than normal at 12 dpi. The strong correlation between cardiac histopathology score and chemokine expression level suggested that the chemokines might play a role in pathological changes during early myocarditis stage. In addition, we also found that both cell survival signaling pathways (AKT1, p38MAPK) and antiviral signaling pathways (IKKα/β/ε) were activated and promoted the recovery during late myocarditis stage. Altogether, our observations improved the understanding of formation and progression of the pathological lesions, as well as the repair mechanism for acute viral myocarditis.

Vitamin D3 as a novel regulator of basic fibroblast growth factor in chronic rhinosinusitis with nasal polyposis

BACKGROUND

The immunopathogenesis of chronic rhinosinusitis (CRS) is largely unknown, but it is thought that different inflammatory profiles are responsible for the different CRS subtypes. 25-Hydroxyvitamin-D (25-VD3) has been shown to alter inflammatory mediators in other disease processes and 25-VD3 deficiency is associated with CRS with nasal polyps (CRSwNP), but it is unknown if 25-VD3 levels impact local inflammation in CRS. This study investigated the correlation between plasma 25-VD3 and sinonasal mucus monocyte chemoattractant protein-1 (MCP-1), regulated upon activation normal T cell expressed and secreted (RANTES), and basic fibroblast growth factor (bFGF) levels in patients with CRS.

METHODS

Study subjects undergoing endoscopic sinus surgery (ESS) for CRS were prospectively enrolled from January 2012 to August 2014. Control subjects included patients undergoing ESS for noninflammatory pathology. Blood and sinonasal mucus were collected at the time of ESS. Plasma 25-VD3 was measured by enzyme-linked immunosorbent assay (ELISA) and mucus levels of MCP-1, RANTES, and bFGF by cytometric bead array (CBA).

RESULTS

A total of 57 patients were enrolled and categorized as CRS without nasal polyps (CRSsNP) (n = 31), CRSwNP (n = 14), and controls (n = 12). No significant correlation was found between MCP-1 and 25-VD3. There was a significant negative correlation between 25-VD3 and RANTES (r = -0.612; p = 0.026) and bFGF (r = -0.578; p = 0.039) in CRSwNP patients; however, there was no significant correlation in CRSsNP patients.

CONCLUSION

This data suggests that 25-VD3 may play a role in regulation of RANTES and bFGF expression in CRSwNP. This may occur through regulation of NP fibroblasts or other immune cells. Further investigation is warranted to better elucidate the role of RANTES, bFGF, and 25-VD3 in CRSwNP.

Vitamin D decreases the secretion of eotaxin and RANTES in nasal polyp fibroblasts derived from Taiwanese patients with chronic rhinosinusitis with nasal polyps

Eosinophils are important inflammatory cells involved in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP). Vitamin D and its derivatives, in addition to their classic role as regulators of electrolytes homeostasis, have modulatory effects in immunological and inflammatory responses. Such properties suggest that vitamin D might also play a role in inflammatory airway diseases such as CRSwNP. In this study, we investigated the effect of vitamin D derivatives (calcitriol and tacalcitol) on the secretion of eotaxin and Regulated on Activation, Normal T Cell Expressed and Secreted (RANTES), the two major eosinophil chemoattractants, in fibroblasts derived from the polyps of Taiwanese CRSwNP patients. Patients diagnosed with eosinophilic CRSwNP but without malignancies or asthma and undergoing elective endoscopic sinus surgery were recruited. Three primary fibroblast cultures were established using the polyp specimens obtained from these patients. The third to eighth passages of the fibroblasts were used for in vitro studies. Nasal polyp-derived fibroblasts were stimulated with IL-1β (10 ng/mL) for 24 hours, followed by replacement with media alone or with calcitriol or tacalcitol (10 μM) and incubation for another 24 hours. After the treatments, the levels of secreted eotaxin and RANTES were evaluated by ELISA assays. The results showed that IL-1β could substantially stimulate the secretion of eotaxin (p < 0.01) and RANTES (p < 0.01) in nasal polyp-derived fibroblasts. More importantly, this stimulatory effect was significantly suppressed by adding calcitriol (p ≤ 0.002 for eotaxin and p ≤ 0.008 for RANTES) or tacalcitol (p ≤ 0.009 for eotaxin and p ≤ 0.02 for RANTES). Therefore, the inhibitory effect of vitamin D derivatives on eotaxin and RANTES secretion might shed light not only on the disease mechanism, but also on the potential use of vitamin D in pharmacotherapy of Taiwanese patients with CRSwNP.

Vitamin D analogs decrease in vitro secretion of RANTES and enhance the effect of budesonide

PURPOSE

Eosinophils appear to be central inflammatory cells in the pathogenesis of rhinosinusitis with nasal polyps (NP). One of the most predominantly recognized eosinophil chemoattractants is RANTES. The aim of this study was to assess the influence of vitamin D (VD) derivates on RANTES expression in the culture of nasal polyp fibroblasts.

MATERIAL AND METHODS

NP fibroblast cell cultures derived from 16 patients with NP were first stimulated with bacterial LPS and than incubated in increasing concentrations (from 10(-7)M to 10(-4)M) of calcitriol, tacalcitol or budesonide and in combination with one of VD derivate with budesonide in 1:1, 1:3 and 3:1 ratios. Quantitative analysis of RANTES level was conducted in culture supernatants using an ELISA method.

RESULTS

The highest calcitriol concentration (10(-4)M) as well as tacalcitol at 10(-5)M and 10(-4)M reduced RANTES production significantly compared to the control (201.1pg/ml, 338.7pg/ml, 211.3pg/ml v 571.78pg/ml; p<0.05). Budesonide and calcitriol administered in 1:3 ratio and budesonide and tacalcitol in 1:1 and 1:3 reduced RANTES concentration significantly better than each of the drug used in monotherapy (p<0.05). Budesonide and tacalcitol in 1:1 and 1:3 ratios suppressed RANTES production to the lowest level (171.8±97.6pg/ml and 178.7±105.22pg/ml, respectively).

CONCLUSION

Active VD compounds via downregulation of RANTES production exert a potential role as a complementary element in the therapy of chronic rhinosinusitis with NP. Compounds consisting of budesonide and VD derivate have an advantage over both drugs used in monotherapy.

Immunological stimuli change expression of genes and neutrophil function in fathead minnow Pimephales promelas Rafinesque

Fathead minnows Pimephales promelas were exposed to lipopolysaccharide (LPS) and polyinosinic-polycytidylic acid [poly(I:C)] to observe immunological responses during simulated bacterial and viral challenge at the level of gene expression and granulocyte function. Complementary DNA libraries were created from LPS- and poly(I:C)-treated fish and c. 5000 expressed sequence tags (ESTs) were sequenced. The ESTs were subjected to BLASTx analysis and 1500 genes were annotated, grouped by function and 20 immune genes were selected for expression studies by real-time PCR. Lipopolysaccharide treatment significantly downregulated expression of interferon regulatory factor 2 binding protein 1 (nine-fold), Chemokine (C-X-C motif) ligand 12a (three-fold) and TNF-related apoptosis-inducing ligand, TRAIL (two-fold). In poly(I:C)-treated fish, a significant upregulation was observed for IFN-inducible and antiviral proteins belonging to the family of Mx proteins (73-fold) and chemokine CCL-C5a (28-fold). Blood neutrophil count was significantly increased in poly(I:C)-treated fish at 24 and 48 h post-injection. Neutrophil extracellular trap release and respiratory burst of kidney granulocytes were suppressed in poly(I:C)-treated fish, while degranulation of primary granules was not affected significantly by the treatment. The changes in gene expression and neutrophil function in P. promelas exposed to LPS and poly(I:C) support the use of this species as an alternative model for studies of pathogen effects on the innate immune system of fishes.

CCL5 as an adjuvant for cancer immunotherapy

IMPORTANCE OF THE FIELD

To date cancer immunotherapy has only achieved limited clinical efficacy, thus more efficient immunotherapeutic approaches need to be explored. The CC chemokine CCL5 plays a role in chemoattraction and activation of immune cells implying its potential clinical application as an adjuvant for boosting anti-tumor immunity, although an effect on carcinogenesis and tumor cell invasiveness is also reported to be associated with CCL5.

AREAS COVERED IN THIS REVIEW

Recent progress in exploiting CCL5 as an adjuvant for cancer prevention and treatment, and updated understanding on how CCL5 is involved in tumor invasiveness and carcinogenesis.

WHAT THE READER WILL GAIN

CCL5 represents a natural adjuvant for enhancing anti-tumor immune responses. However, animal experiments and clinical reports suggest that CCL5 plays a role in carcinogenesis and invasiveness of tumor cells. Therefore, a CCL5-based cancer therapeutic approach needs to avoid the CCL5-associated potential detrimental effects.

TAKE HOME MESSAGE

CCL5 has a pre-eminent role in chemotaxis and activation of a wide spectrum of immune cells. CCL5 functions as an adjuvant to boost anti-tumor immunity by diverse protocols such as co-immunization of recombinant CCL5 protein with tumor-associated antigen, vaccination with CCL-5-expressing tumor cells, or viral vector delivery of CCL5 cDNA into growing tumor. CCL5 may also promote tumor cell survival, proliferation and invasion by different mechanisms.

Targeted delivery of PSC-RANTES for HIV-1 prevention using biodegradable nanoparticles

PURPOSE

Nanoparticles formulated from the biodegradable co-polymer poly(lactic-co-glycolic acid) (PLGA), were investigated as a drug delivery system to enhance tissue uptake, permeation, and targeting for PSC-RANTES anti-HIV-1 activity.

MATERIALS AND METHODS

PSC-RANTES nanoparticles formulated via a double emulsion process and characterized in both in vitro and ex vivo systems to determine PSC-RANTES release rate, nanoparticle tissue permeation, and anti-HIV bioactivity.

RESULTS

Spherical, monodisperse (PDI = 0.098 +/- 0.054) PSC-RANTES nanoparticles (d = 256.58 +/- 19.57 nm) with an encapsulation efficiency of 82.23 +/- 8.35% were manufactured. In vitro release studies demonstrated a controlled release profile of PSC-RANTES (71.48 +/- 5.25% release). PSC-RANTES nanoparticle maintained comparable anti-HIV activity with unformulated PSC-RANTES in a HeLa cell-based system with an IC(50) of approximately 1pM. In an ex vivo cervical tissue model, PSC-RANTES nanoparticles displayed a fivefold increase in tissue uptake, enhanced tissue permeation, and significant localization at the basal layers of the epithelium over unformulated PSC-RANTES.

CONCLUSIONS

These results indicate that PSC-RANTES can readily be encapsulated into a PLGA nanoparticle drug delivery system, retain its anti-HIV-1 activity, and deliver PSC-RANTES to the target tissue. This is crucial for the success of this drug candidate as a topical microbicide product.

Chemokines and Chemokine Receptors Critical to Host Resistance following Genital Herpes Simplex Virus Type 2 (HSV-2) Infection

HSV-2 is a highly successful human pathogen with a remarkable ability to elude immune detection or counter the innate and adaptive immune response through the production of viral-encoded proteins. In response to infection, resident cells secrete soluble factors including chemokines that mobilize and guide leukocytes including T and NK cells, neutrophils, and monocytes to sites of infection. While there is built-in redundancy within the system, chemokines signal through specific membrane-bound receptors that act as antennae detailing a chemical pathway that will provide a means to locate and eliminate the viral insult. Within the central nervous system (CNS), the temporal and spatial expression of chemokines relative to leukocyte mobilization in response to HSV-2 infection has not been elucidated. This paper will review some of the chemokine/chemokine receptor candidates that appear critical to the host in viral resistance and clearance from the CNS and peripheral tissue using murine models of genital HSV-2 infection.

Interactions between eotaxin and interleukin-5 in the chemotaxis of primed and non-primed human eosinophils

This study was designed to understand the relationship between interleukin-5 and eotaxin in modulating the chemotaxis of eosinophils obtained from healthy subjects and subjects with allergic rhinitis. Chemotaxis of eosinophils from patients with allergic rhinitis toward interleukin-5 (0.25 ng/ml) was 78% higher than that of healthy subjects. Incubation of eosinophils with eotaxin (100 ng/ml) did not change the interleukin-5-induced chemotaxis of eosinophils from healthy subjects, but it reversed the enhanced chemotaxis seen in eosinophils from allergic patients. Chemotaxis of eosinophils from patients with allergic rhinitis toward eotaxin (100 ng/ml) was 65% higher than that of eosinophils from healthy subjects. Incubation of eosinophils with interleukin-5 (100 ng/ml) significantly increased the eotaxin-induced chemotaxis in both subject groups, but such increases were markedly higher for cells from patients with allergic rhinitis. Our finding that eotaxin inhibits the enhanced eosinophil chemotaxis toward interleukin-5 in primed cells suggests that this chemokine may downregulate eosinophil accumulation in the nasal mucosa of allergic patients.

CCL5 Modulates Pneumococcal Immunity and Carriage

Understanding the requirements for protection against pneumococcal carriage and pneumonia will greatly benefit efforts in controlling these diseases. Recently, it has been shown that genetic polymorphisms can result in diminished expression of CCL5, which results in increased susceptibility to and progression of infectious diseases. We show that CCL5, together with Th cytokine mRNA expression, is temporally up-regulated during pneumococcal carriage. To determine the contribution of CCL5 to pneumococcal surface antigen A-specific humoral and cellular pneumococcal immunity, mice were treated with anti-CCL5 or control Abs before and during Streptococcus pneumoniae strain EF3030-challenge for the initiation of carriage. CCL5 blockade resulted in a decrease of CD4(+) and CD8(+) T cells as well as CD11b(+) cells in the spleen, cervical lymph node, lung, and nasopharyngeal associated lymphoid tissue during the recognition phase of the pneumococcal adaptive immune response. CCL5 blockade significantly reduced the Ag-specific IgG2a and IgG1 Abs in serum and IgA Ab levels in nasal washes. These decreases also corresponded to reductions in Ag-specific T cell (mucosal and systemic) responses. CCL5 inhibition resulted in decreasing the quantity of IL-4- and IFN-gamma-secreting CD4(+) T cells and increasing the number of Ag-specific IL-10-producing CD4(+) T cells; these changes combined also corresponded with the transition from pneumococcal carriage to lethal pneumonia. These data suggest that CCL5 is an essential factor for the induction and maintenance of protective pneumococcal immunity.

Effects of steroid treatment on lung CC chemokines, apoptosis and transepithelial cell clearance during development and resolution of allergic airway inflammation

BACKGROUND

Steroid treatment of allergic eosinophilic airway diseases is considered to attenuate cell recruitment by inhibiting several chemokines and to cause eosinophil clearance through inducement of apoptosis of these cells. However, roles of these mechanisms in the actions of steroids in vivo have not been fully established. Also, as regards clearance of tissue eosinophils other mechanisms than apoptosis may operate in vivo.

OBJECTIVE

This study explores anti-inflammatory effects of steroids instituted during either development or resolution of airway allergic inflammation.

METHODS

Immunized mice were subjected to week-long daily allergen challenges (ovalbumin). Steroid treatment was instituted either amidst the challenges or exclusively post-allergen challenge. CC chemokines, goblet cell hyperplasia, occurrence of eosinophil apoptosis, and airway tissue as well as lumen eosinophilia were examined at different time-points.

RESULTS

Daily steroids instituted amid the allergen challenges non-selectively attenuated a range of chemokines, permitted egression of tissue eosinophils into airway lumen to increase, and reduced development of lung tissue eosinophilia. Steroid treatment instituted post-challenge selectively inhibited the CC-chemokine regulation upon activation, normal T cell expressed and secrted (RANTES), permitted continued egression of eosinophils into airway lumen, and resolved the tissue eosinophilia. Eosinophil apoptosis rarely occurred at development and resolution of the allergic eosinophilic inflammation whether the animals were steroid treated or not. However, anti-Fas monoclonal antibodies given to mice with established eosinophilia post-challenge produced apoptosis of the tissue eosinophils indicating that apoptotic eosinophils, if they occur, are well detectible in vivo.

CONCLUSION

Airway tissue eosinophils are likely eliminated through egression into airway lumen with little involvement of apoptosis and phagocytosis. Our data further suggest that therapeutic steroids may resolve airway inflammation by permitting clearance of tissue eosinophils through egression and inhibiting RANTES-dependent cell recruitment to lung tissues.

The therapeutic potential in targeting CCR5 and CXCR4 receptors in infectious and allergic pulmonary disease

Targeting chemokines and chemokine receptors in various acute and chronic pulmonary diseases remains a vibrant area of basic and clinical research despite major hurdles including cross-species barriers, toxicity, and redundancy. In this review, we draw upon our basic research with a murine model in which innate and acquired immunity are linked in the development and maintenance of chronic asthma due to Aspergillus fumigatus. Using intact and genetically altered mice, studies have also been undertaken to elucidate safe and effective therapeutic strategies that interrupt the initiation and amplification of inflammatory and immune events that follow the intrapulmonary introduction of Aspergillus into A. fumigatus-sensitized mice. These events include resident immune cell activation, immune and inflammatory cell recruitment to the airways, changes in lung physiology, and profound changes in the architecture of the airway due to the activation of lung resident cells. The expression of 2 major chemokine receptors, namely, CC chemokine receptor (CCR) 5 and CXC chemokine receptor (CXCR) 4, has been identified and their roles in innate and acquired immune events during fungal asthma have been explored. CCR5 and CXCR4 are best known for their roles in human immunodeficiency virus-1 (HIV-1) infection, but both are attractive targets in the context of overt inflammatory and remodeling responses in the lung. This avenue of research is markedly enhanced by the existence of numerous small molecule antagonists that are available to selectively target these receptors.

Involvement of histamine H1 and H2 receptors in the regulation of STAT-1 phosphorylation: inverse agonism exhibited by the receptor antagonists

Signal transducer and activator of transcription-1 (STAT1) is a latent signal transducer protein which, on phosphorylation, is translocated from the cytoplasm to the nucleus and is subsequently activated. This study was designed to determine the involvement of histamine receptors in histamine-mediated effect on STAT1 phosphorylation. It is known that the actions of histamine mediated through H1 and H2 receptors are dependent on their respective downstream pathways, Ca(2+)-PKC and cAMP-PKA. In this study, we investigated the significance of PKA in STAT1 phosphorylation. C57BL/6 mouse splenocytes were isolated and treated with histamine (10(-7)-10(-4) M) and then activated with PMA (phorbol 12 myristate 13-acetate) plus ionomycin. The phosphorylated STAT1 levels were analyzed by immunoblotting. Histamine receptor agonists amthamine and betahistine, histamine receptor antagonists pyrilamine maleate, tripelennamine, ranitidine, cimetidine and thioperamide, cAMP agonists N(6), 2'-0-dibutyryladenosine-3',5'-cyclic monophosphate sodium salt (db-cAMP) and forskolin, protein kinase A inhibitors N-(2-[p-bromocinnamylamino]ethyl)-5-isoquinoline-sulfonamide (H89) and Rp diastereomer of adenosine cyclic 3',5'-phosphorothioate (RpcAMPs) and tyrosine kinase inhibitor tyrphostin were used to identify the upstream signal transduction pathways. We observed that histamine augmented the phosphorylation of STAT1 through both H1 and H2 receptors. Furthermore, H1 and H2 receptor antagonists displayed inverse agonism. Ca(2+)-PKC-induced phosphorylation of STAT1 was completely inhibited by H89 and significantly inhibited by RpcAMPs. DbcAMP and forskolin augmented the Ca(2+)-PKC-induced STAT1 phosphorylation thus suggesting a convergent crosstalk between the two histamine receptor signaling pathways, PKA and PKC.

Chemokine RANTES promoter polymorphisms in allergic rhinitis

OBJECTIVES/HYPOTHESIS

RANTES is one of the most widely studied of the chemokines linked to allergic diseases. Two polymorphisms of the RANTES promoter region (-403 G/A and -28 C/G) have been found. The authors investigated whether these RANTES promoter polymorphisms were associated with allergic rhinitis.

STUDY DESIGN

Case-control study.

METHODS

Blood samples for genetic analysis were obtained from 151 individuals with allergic rhinitis and from 278 healthy individuals without atopic disease. Polymerase chain reaction-based assays for detection of the -403 G/A and -28 C/G polymorphisms of the RANTES gene were used for genotyping.

RESULTS

The frequencies of both the RANTES -403A and -28G alleles were significantly higher in patients with allergic rhinitis than in control subjects (P <.05 for both).

CONCLUSION

The study results indicated that the -403 and -28 alleles in the RANTES promoter region belong to the predictor gene set for allergic rhinitis and could be used in genomic analysis.

Functional expression and characterization of macaque C-C chemokine receptor 3 (CCR3) and generation of potent antagonistic anti-macaque CCR3 monoclonal antibodies

Eosinophils are major effector cells implicated in a number of chronic inflammatory diseases in humans, particularly bronchial asthma and allergic rhinitis. The beta-chemokine receptor C-C chemokine receptor 3 (CCR3) provides a mechanism for the selective recruitment of eosinophils into tissue and thus has recently become an attractive biological target for therapeutic intervention. In order to develop in vivo models of inflammatory diseases, it is essential to identify and characterize the homologues of human eotaxin (C-C chemokine ligand 11) and CCR3 from other species, such as non-human primates. Accordingly, we cloned the macaque eotaxin and CCR3 genes and revealed that they were 91 and 92% identical at the amino acid level to their human homologues, respectively. Macaque CCR3 expressed in the murine pre-B L1-2 cell line bound macaque eotaxin with high affinity (K(d) = 0.1 nm) and exhibited a robust eotaxin-induced Ca(2+) flux and chemotaxis. Characterization of beta-chemokines on native macaque CCR3 on eosinophils was performed by means of eotaxin-induced shape change in whole blood using a novel signaling assay known as gated autofluorescence forward scatter. Additionally, mAbs were raised against macaque CCR3 using two different immunogens: a 30-amino acid synthetic peptide derived from the predicted NH(2) terminus of macaque CCR3 and intact macaque CCR3-transfected cells. These anti-macaque CCR3 monoclonal antibodies exhibited potent antagonist activity in receptor binding and functional assays. The characterization of the macaque eotaxin/CCR3 axis and development of antagonistic anti-macaque CCR3 monoclonal antibodies will facilitate the development of CCR3 small molecule antagonists with the hope of ameliorating chronic inflammatory diseases in humans.

Eotaxin but not MCP-3 induces eosinophil influx into nasal fluid in allergic patients

BACKGROUND

Eotaxin and MCP-3 (CC chemokines), owing to their preferential action on eosinophils, seem to be the very importance in the patophysiology of allergic rhinitis and asthma. The purpose of this study was to examine the effect of intranasally administered eotaxin and MCP-3 after specific allergen priming on the influx of inflammatory cells and their soluble mediators into the nasal mucosa.

METHODS

Eotaxin and MCP-3 have been applied intranasally at the increasing doses of 1, 5 and 10 microg to allergic patients after allergen priming. The 'nasal pool' technique was used. The cell count and biochemical parameters in nasal lavage were evaluated before 30 min, and 4 and 24 h after the challenge with chemokines.

RESULTS

Both eotaxin and MCP-3 induced the increase in clinical 'score' lasting till 24 h. Eosinophil influx into nasal mucosa after provocation with eotaxin was also observed. The challenge with MCP-3 did not induce any significant changes in nasal lavage fluid.

CONCLUSIONS

Eotaxin is likely to play an important role in the pathogenesis of allergic conditions in humans. MCP-3 did not induce inflammatory cell influx into nasal mucosa. The role of this chemokine in the pathogenesis of allergic inflammation is difficult to assess and requires further studies.

Herpes simplex virus selectively induces expression of the CC chemokine RANTES/CCL5 in macrophages through a mechanism dependent on PKR and ICP0

Recruitment of leukocytes is essential for eventual control of virus infections. Macrophages represent a leukocyte population involved in the first line of defense against many infections, including herpes simplex virus (HSV) infection. Through presentation of antigens to T cells and production of cytokines and chemokines, macrophages also constitute an important link between the innate and adaptive immune systems. Here, we have investigated the chemokine expression profile of macrophages after HSV infection and the virus-cell interactions involved. By reverse transcription-PCR and cDNA arrays, we found that HSV type 1 (HSV-1) and HSV-2 induced expression of the CC chemokine RANTES/CCL5 in murine macrophage cell lines and peritoneal cells. The CXC chemokine BCA-1/CXCL13 was also induced in peritoneal cells. Twenty-six other chemokines tested were not affected. Accumulation of RANTES mRNA was detectable after 5 h of infection, was sensitive to UV irradiation of the virus, and was preceded by accumulation of viral immediate-early mRNA and proteins. The viral components responsible for initiation of RANTES expression were examined with virus mutants and RAW 264.7 macrophage-like cells expressing a dominant negative mutant of the double-stranded-RNA-activated protein kinase (PKR). The PKR mutant cell line displayed reduced constitutive and HSV-inducible RANTES expression compared to the control cell line. HSV-1 mutants deficient in genes encoding the immediate-early proteins ICP4, ICP22, and ICP27 remained fully capable of inducing RANTES expression in macrophages. By contrast, the ability of an ICP0-deficient HSV-1 mutant to induce RANTES expression was compromised. Thus, HSV selectively induces expression of RANTES in macrophages through a mechanism dependent on cellular PKR and viral ICP0.

Allergic rhinitis: not purely a histamine-related disease

Allergic rhinitis is an inflammatory disorder of the nasal mucosa typified by the symptoms of nasal itch, sneeze, anterior nasal secretions, and nasal blockage. These symptoms arise from the interaction between mediators and neural, vascular, and glandular structures within the nose. Nasal itch, sneezes, and rhinorrhoea are predominantly neural in origin, while nasal obstruction is predominantly vascular. Nasal biopsy studies show accumulation of eosinophils within the lamina propria and epithelium and an increase in tissue and cell surface basophils in both seasonal and perennial allergic rhinitis. These cells are in an activated state. Within the epithelium, increased numbers of mast cells, T cells and Langerhans' cells, which induce T-cell activation, are found. The accumulation of these cells can be linked to chemokine and cytokine generation by the epithelial cells themselves. Thus, the tissue cell recruitment is orchestrated by activated mast cells, T cells, and epithelial cells, with the recruited tissue eosinophils also contributing to their persistence at this site through autocrine mechanisms. Mast cells generate an array of mediators including histamine, tryptase, leukotrienes, and prostaglandins. Histamine is also generated by basophils. Eosinophils and basophils contribute to the leukotriene synthesis within the tissue. Histamine nasal insufflation induces nasal itch, sneeze, and rhinorrhoea as well as nasal blockage, thereby reproducing all the symptoms of allergic rhinitis. These effects are primarily mediated by H1-receptors, and H1-receptor antagonists are a prominent treatment. Antagonism of histamine at these receptors reduces symptoms by about 40-50%, with the greatest effect on the neurally mediated responses. Thus, histamine is a major mediator of allergic rhinitis, but not the sole contributor. Nasal insufflation with leukotrienes, prostaglandins, or kinins is associated with the development of nasal blockage. These mediators act primarily on the nasal vasculature and, in this respect, leukotrienes are potent mediators. Leukotrienes also induce plasma protein exudation, which contributes to the anterior nasal secretions. Studies with combination products have suggested that modifying the effects of both leukotrienes and histamine has complementary effects in relieving nasal symptoms, indicating that both these mediators are relevant to disease expression.

Differential expression of RANTES chemokine, TGF-beta, and leukocyte phenotype in acute cellular rejection and quilty B lesions

BACKGROUND

Because of the complexity of the trabeculated endocardial surface and tangential histologic sectioning, the differentiation of acute cellular rejection (ACR) from Quilty B lesions (QB) in endomyocardial biopsies (EMBs) is problematic. We hypothesized that the phenotype chemokine RANTES (regulated upon activation, normal T cell expressed and secreted) expression of infiltrating cells and the pattern of expression of transforming growth factor-beta (TGF-beta) may distinguish ACR from QB. In previous studies, the number of RANTES-positive cells and the expression of TGF-beta correlated with the severity of rejection.

METHODS

We used immunohistochemical techniques to stain sections of human EMBs with only QB (n = 14) or with only ACR (International Society for Heart and Lung Transplantation Grades 1A and 1B, n = 7; Grades 3A and 3B, n = 7) for B (CD20) and T-lymphocytes (CD3), macrophages (CD68), RANTES, and TGF-beta expression. We graded the percentage of positive cells from 0 to 4 (1 = 1% to 25%; 2 = 26% to 50%; 3 = 51% to 75%, and 4 = 76% to 100%).

RESULTS

When ACR was compared with QB, we found no difference in the proportion of myocardial B cells (0.9 +/- 0.3 vs 1.1 +/- 0.3, p = 0.17); however, we found a lesser proportion of T cells (1.8 +/- 0.5 vs. 2.8 +/- 0.9, p <0.01) but more macrophages (2.9 +/- 0.5 vs. 1.1 +/- 0.6, p < 0.0001) in ACR than in QB. We also found more RANTES-positive leukocytes in ACR vs. QB (2.8 +/- 1.3 vs. 1.9 +/- 0.9, p = 0.03). In QB, many endocardial vessels stained for TGF-beta (2.9 +/- 1.6). Myocardial vessels and injured myocytes in both ACR and QB expressed TGF-beta.

CONCLUSIONS

In ACR, although T-lymphocytes are numerous, more than 50% of infiltrating cells are macrophages and more than 50% express RANTES. In QB lesions, more than 50% of infiltrating cells are T-lymphocytes and less that 50% of leukocytes will express RANTES. B cells are present in both ACR and QB, but on average comprise only 25% of the cells present. Thus, a relatively simple immunohistochemical analysis of endomyocardial biopsies may be useful in distinguishing ACR from QB.

Regulation of allergic airways inflammation by cytokines and glucocorticoids

Cytokines mediate the allergic inflammatory response of the airways, and glucocorticosteroids ameliorate allergy symptoms by regulating cytokine expression. Recent studies provide insight into the manner by which cytokines work together to mediate allergic airway disease. Real progress has also been gained in our understanding of subcellular mechanisms of allergic inflammation, particularly the role of transcription factors in regulating the expression of specific cytokine profiles and the differentiation of the TH2 subset. This article provides an update of recently reported findings in this field and highlights emerging concepts of allergic inflammation.

RANTES potentiates antigen-specific mucosal immune responses

RANTES is produced by lymphoid and epithelial cells of the mucosa in response to various external stimuli and is chemotactic for lymphocytes. The role of RANTES in adaptive mucosal immunity has not been studied. To better elucidate the role of this chemokine, we have characterized the effects of RANTES on mucosal and systemic immune responses to nasally coadministered OVA. RANTES enhanced Ag-specific serum Ab responses, inducing predominately anti-OVA IgG2a and IgG3 followed by IgG1 and IgG2b subclass Ab responses. RANTES also increased Ag-specific Ab titers in mucosal secretions and these Ab responses were associated with increased numbers of Ab-forming cells, derived from mucosal and systemic compartments. Splenic and mucosally derived CD4(+) T cells of RANTES-treated mice displayed higher Ag-specific proliferative responses and IFN-gamma, IL-2, IL-5, and IL-6 production than control groups receiving OVA alone. In vitro, RANTES up-regulated the expression of CD28, CD40 ligand, and IL-12R by Ag-activated primary T cells from DO11.10 (OVA-specific TCR-transgenic) mice and by resting T cells in a dose-dependent fashion. These studies suggest that RANTES can enhance mucosal and systemic humoral Ab responses through help provided by Th1- and select Th2-type cytokines as well as through the induction of costimulatory molecule and cytokine receptor expression on T lymphocytes. These effects could serve as a link between the initial innate signals of the host and the adaptive immune system.

Chemokines in the limbal form of vernal keratoconjunctivitis

BACKGROUND/AIMS

Chemokines are a family of low molecular weight cytokines that attract and activate leucocytes. The CC chemokines act on eosinophils, basophils, monocytes, and lymphocytes, suggesting that they play an important part in allergic diseases. The aims of this study were to investigate the expression of the CC chemokines, RANTES, eotaxin, monocyte chemotactic protein (MCP) 1, MCP-2, and MCP-3 in the conjunctiva of patients with vernal keratoconjunctivitis (VKC) and to determine the cellular source of these chemokines.

METHODS

Conjunctival biopsy specimens from nine subjects with active VKC, and six control subjects were studied by immunohistochemical techniques using a panel of monoclonal and polyclonal antibodies directed against RANTES, eotaxin, MCP-1, MCP-2, and MCP-3. The phenotype of inflammatory cells expressing chemokines was examined by sequential double immunohistochemistry.

RESULTS

In the normal conjunctiva, superficial epithelial cells showed a constitutive, weak cytoplasmic expression of eotaxin. Few inflammatory cells in the perivascular areas expressed RANTES, MCP-1, MCP-2, and MCP-3. In VKC specimens, the epithelium showed intense cytoplasmic eotaxin staining in all cells, and cytoplasmic RANTES staining mainly in the superficial layers. Furthermore, RANTES and eotaxin were expressed on the vascular endothelium mainly in the upper substantia propria. Compared with normal controls, VKC specimens showed significantly more inflammatory cells expressing RANTES, eotaxin, MCP-1, and MCP-3 (p<0.001, 0.0028, 0.0092, and <0. 001, respectively). In VKC specimens, the numbers of inflammatory cells expressing RANTES were significantly higher than the numbers of inflammatory cells expressing eotaxin, MCP-1, and MCP-2 (all p values <0.001). Colocalisation studies revealed that the majority of inflammatory cells expressing chemokines were CD68 positive monocytes/macrophages.

CONCLUSIONS

These results demonstrate an increase in the expression of RANTES, eotaxin, MCP-1, and MCP-3 in the conjunctiva of patients with VKC compared with control subjects. These data suggest a potential role for these chemokines in the pathogenesis of VKC. Antagonists of chemokine receptors may provide new therapeutic modalities in VKC.

Neuropeptide-induced chemotaxis of eosinophils in pulmonary diseases

Eosinophilic lung diseases include various disease entities, and the incidence of pulmonary infiltration with eosinophilia is on the rise. Because eosinophils, well known as inflammatory cells, respond to peripheral neuropeptides in vitro and in vivo, and these peptides are also present in human airway nerves, their interactions are thought to play a major role in the initiation and perpetuation of inflammatory lung diseases. This article reviews the current literature on eosinophil biology and interactions of these cells with the neuroendocrine system. Also, implications of tachykinins and other neuropeptides in eosinophilic pulmonary diseases is discussed based on recently investigated mechanisms. Eosinophils and sensory nerves most likely influence each other in a two-directional way in the pathogenesis of pulmonary diseases. Although release of sensory neuropeptides is involved in most conditions of airway hyperresponsiveness, increased bronchial resistance, and lung eosinophilia, the role of these nervous system-derived mediators in pulmonary diseases may be underestimated.

Expression of RANTES by IL-1 beta and TNF-alpha stimulated nasal polyp fibroblasts

OBJECTIVE

Accumulation of eosinophils (Eo) is one of the most characteristic feature of nasal polyps. However, the question remains why eosinophils accumulate into the nasal polyp tissue. RANTES (regulated upon activation, normal T cell expressed and presumably secreted) is a recently described chemokine that is said to play a role in the recruitment of eosinophils into inflammatory tissue sites. Fibroblasts are a rich source of cytokines and inflammatory mediators. The objective of this study was to demonstrated the expression of the chemokine RANTES in nasal polyp fibroblasts after stimulation with proinflammatory cytokines like TNF-alpha and IL-1 beta.

METHODS

Fibroblast lines were established from human nasal polyp biopsy tissues taken from patients with chronic sinusitis who had no other associated diseases. Cultured nasal polyp fibroblasts were stimulated with TNF-alpha or IL-1 beta at various doses (0.1, 1.0, 1 ng/ml) or for various times (l, 6, 12, 24, 48, 72 h). To detect the RANTES gene expression, RT-PCR was performed. The resulting supernatants were assayed with ELISA for the level of RANTES.

RESULTS

We demonstrated that TNF-alpha and IL-1 beta induced the gene expression and protein production of RANTES in nasal polyp fibroblasts. This responsiveness to TNF-alpha and IL-1 beta was time and dose-dependent.

CONCLUSION

These findings suggest that nasal polypfibroblasts may also play an important role in the recruitment of Eo through the production of RANTES.

Migration of eosinophils across endothelial cell monolayers: interactions among IL-5, endothelial-activating cytokines, and C-C chemokines

Eosinophils are the predominant cell type recruited in inflammatory reactions in response to allergen challenge. The mechanisms of selective eosinophil recruitment in allergic reactions are not fully elucidated. In this study, the ability of several C-C chemokines to induce transendothelial migration (TEM) of eosinophils in vitro was assessed. Eotaxin, eotaxin-2, monocyte chemotactic protein (MCP)-4, and RANTES induced eosinophil TEM across unstimulated human umbilical vein endothelial cells (HUVEC) in a concentration-dependent manner with the following rank order of potency: eotaxin approximately eotaxin-2 > MCP-4 approximately RANTES. The maximal response induced by eotaxin or eotaxin-2 exceeded that of RANTES or MCP-4. Preincubation of eosinophils with anti-CCR3 Ab (7B11) completely blocked eosinophil TEM induced by eotaxin, MCP-4, and RANTES. Activation of endothelial cells with IL-1beta or TNF-alpha induced concentration-dependent migration of eosinophils, which was enhanced synergistically in the presence of eotaxin and RANTES. Anti-CCR3 also inhibited eotaxin-induced eosinophil TEM across TNF-alpha-stimulated HUVEC. The ability of eosinophil-active cytokines to potentiate eosinophil TEM was assessed by investigating eotaxin or RANTES-induced eosinophil TEM across resting and IL-1beta-stimulated HUVEC in the presence or absence of IL-5. The results showed synergy between IL-5 and the chemokines but not between IL-5 and the endothelial activator IL-1beta. Our data suggest that eotaxin, eotaxin-2, MCP-4, and RANTES induce eosinophil TEM via CCR3 with varied potency and efficacy. Activation of HUVEC by IL-1beta or TNF-alpha or priming of eosinophils by IL-5 both promote CCR3-dependent migration of eosinophils from the vasculature in conjunction with CCR3-active chemokines.

Molecular pathology of allergic disease. II: Upper airway disease

Allergic upper airway diseases such as allergic rhinitis and chronic sinusitis are an increasing problem. Although the pathogenesis remains elusive, an individual's genetic predisposition as well as exposure to the allergen are currently considered factors in their development. Clinical symptoms of sneezing, rhinorrhea, and congestion are primarily a consequence of granulocyte release of chemical mediators such as histamine, prostanoids, and leukotrienes as well as the infiltration of inflammatory cells. Observations subsequent to allergen provocation are comparable to natural exposure and as such much of our understanding of allergic responses is derived from this model. A prominence of CD4(+) T cells and eosinophils, synthesis and release of T(H)2 cytokines, and the coordinate expression of chemokines and adhesion molecules are all characteristic of the allergic response observed in rhinitis and sinusitis. Corticosteroids and immunotherapy target these inflammatory processes and have been observed to successfully reduce and shift the predominantly T(H)2 environment toward T(H)1 cytokine expression. As our understanding of the pathophysiologic features of allergic upper airway disease improves, as well as the relationship between their development and that of lower airway disease, new strategies of diagnosis and treatment will allow for more effective modulation of the allergic process and associated morbidity.

Differential roles of IL-18 in allergic airway disease: induction of eotaxin by resident cell populations exacerbates eosinophil accumulation

Cytokine regulation during an allergic response can dictate the severity of the inflammation and resulting injury. In the present study, we have examined the systemic and local effects of IL-18, a Th1-associated cytokine, on a cockroach allergen-induced airway response. In initial studies, temporal increases in IL-18 levels were observed within the lungs. When IL-18 was neutralized systemically the allergen-associated eosinophil accumulation was significantly accelerated 5-fold by 8 h postchallenge, suggesting a regulatory role for IL-18. Recombinant IL-18 (200 ng) was instilled into the airway at the time of allergen challenge to examine whether a direct impact on local eosinophil accumulation could be induced. When IL-18 was instilled, a significant increase in peribronchial eosinophil accumulation was observed in allergic mice as well as in nonallergic mice. A possible mechanism was observed in a significant increase in eotaxin, but not other eosinophil chemotactic factors, in bronchoalveolar lavage fluid after IL-18 instillation. The role of eotaxin was confirmed using eotaxin -/- mice, which demonstrated significantly less eosinophil accumulation compared with littermate controls. IL-18 was subsequently shown to induce eotaxin production from bronchial epithelial cells and isolated macrophages in in vitro assays. The clinical relevance of these findings was determined in treated mice and demonstrated that neutralization of IL-18 exacerbated, whereas exogenous IL-18 had no effect on airway hyperreactivity. Altogether, these data demonstrate that IL-18 may have multiple functions during an immune response that differ depending upon the local or systemic effects.

C-C chemokine profile of cord blood mononuclear cells: selective defect in RANTES production

Three C-C chemokines inhibit human immunodeficiency virus (HIV) entry into macrophages: macrophage inflammatory protein-1 (MIP-1), MIP-1β, and regulated-upon activation, normal T-cell expressed and secreted (RANTES). We studied the ability of placental cord blood mononuclear cells (CBMC) to secrete these C-C chemokines in comparison to adult blood mononuclear cells (ABMC). CBMC had diminished ability to secrete RANTES, as determined by enzyme-linked immunosorbent assay. Secretion of MIP-1 and MIP-1β were similar in CBMC and ABMC. Whereas MIP-1 and MIP-1β secretion were comparable in monocytes and lymphocytes, RANTES was secreted primarily by lymphocytes. Flow cytometric analysis of RANTES expression showed diminished intracellular RANTES expression in cord blood lymphocytes (CBL) compared to adult (peripheral) blood lymphocytes (ABL). A subset analysis of RANTES-producing CBL and ABL demonstrated that RANTES was produced predominantly by CD8+/CD45RO+ cells. CBL had a reduced proportion of CD8+/CD45RO+ cells compared with ABL, which may account for the diminished RANTES secretion by CBMC. These results may be relevant to the pathogenesis of perinatal HIV infection.

Intranasal administration of eotaxin increases nasal eosinophils and nitric oxide in patients with allergic rhinitis

BACKGROUND

Nitric oxide (NO) plays an important role as an inflammatory mediator in the airways. Inducible NO synthase in the nasal mucosa is upregulated in perennial allergic rhinitis, and nasal NO is reduced after treatment with topical corticosteroids. A previous study has suggested that there is a significant correlation between exhaled NO and sputum eosinophils in patients with asthma.

OBJECTIVE

We investigated the ability of intranasal administration of eotaxin, a potent chemoattractant for eosinophils, to induce eosinophil accumulation and the relationship between eosinophil recruitment in the nasal mucosa and nasal NO production in patients with allergic rhinitis.

METHODS

Nine patients with allergic rhinitis were studied. Eotaxin or diluent was delivered intranasally in patients by using a metered spray pump. Nasal NO, symptom scores, and the influx of inflammatory cells in nasal lavage fluid were assessed before and after the challenge. Immunoreactivity for inducible NO synthase and nitrotyrosine was evaluated in nasal lavage cells.

RESULTS

Eotaxin induced a significant influx of eosinophils (P <.05) with mild symptoms of rhinitis. There was neither significant migration of lymphocytes, basophils, and macrophages into nasal lavage fluid nor a shedding of nasal epithelial cells after eotaxin challenge. Nasal NO was increased significantly (P <.05) 8 hours after eotaxin challenge compared with diluent challenge. Nitrotyrosine immunoreactivity was moderately elevated in nasal epithelial cells after the challenge.

CONCLUSION

We have shown that eotaxin causes chemotaxis of eosinophils with a clinically symptomatic inflammatory response in the nasal mucosa and that eosinophil recruitment accompanies an increase in nasal NO, contributing to oxidative stress.

Chemokines and allergic disease

Understanding the chemokine network has become one of the great challenges for researchers interested in inflammatory mechanisms and inflammation-based diseases. The complexity and diversity of the system provide not only a daunting task for its comprehension but also numerous opportunities for development of new, targeted therapies. It is now certain that chemokines are involved as important mediators of allergic inflammation; the fine details and scope of their roles are now under investigation. Presumably, because of distinct pressures on the immune systems of people living in different geographic regions, genetic variation of ligands, receptors, and regulatory regions in the network have emerged. Establishing the roles of these polymorphisms in determining disease susceptibility or progression among individuals and in distinct ethnic groups will provide a basis for improved understanding and treatment of allergic diseases.