Eotaxin/CCL11 levels correlate with myocardial fibrosis and mast cell density in native and transplanted rat hearts

Myocardial fibrosis contributes to hemodynamic and cardiac functional alterations commonly observed posttransplantation. Cardiac mast cells (MC) have been linked to fibrosis in posttransplantation hearts. Eotaxin, which has been shown to be involved in fibrogenesis, has been demonstrated to be increased in production in cardiac macrophages. The aim of our study was to correlate myocardial fibrosis during heart transplant rejection in the rat with eotaxin/chemokine [c-c motif] ligand 11 (CCL11) expression, and with various subtypes of infiltrating cardiac MC, namely connective-type MC (CTMC) and mucosa-type MC (MMC).

Eotaxin/CCL11 expression by infiltrating macrophages in rat heart transplants during ongoing acute rejection

Eotaxin/CCL11 chemokine is expressed in different organs, including the heart, but its precise cellular origin in the heart is unknown. Eotaxin is associated with Th2-like responses and exerts its chemotactic effect through the chemokine receptor-3 (CCR3), which is also expressed on mast cells (MC). The aim of our study was to find the cellular origin of eotaxin in the heart, and to assess whether expression is changing during ongoing acute heart transplant rejection, indicating a correlation with mast cell infiltration which we observed in a previous study. In a model of ongoing acute heart transplant rejection in the rat, we found eotaxin mRNA expression within infiltrating macrophages, but not in mast cells, by in situ-hybridization. A five-fold increase in eotaxin protein in rat heart transplants during ongoing acute rejection was measured on day 28 after transplantation, compared to native and isogeneic control hearts. Eotaxin concentrations in donor hearts on day 28 after transplantation were significantly higher compared to recipient hearts, corroborating an origin of eotaxin from cells within the heart, and not from the blood. The quantitative comparison of eotaxin mRNA expression between native hearts, isografts, and allografts, respectively, revealed no statistically significant difference after transplantation, probably due to an overall increase in the housekeeping gene's 18S rRNA during rejection. Quantitative RT-PCR showed an increase in mRNA expression of CCR3, the receptor for eotaxin, during ongoing acute rejection of rat heart allografts. Although a correlation between increasing eotaxin expression by macrophages and mast cell infiltration is suggestive, functional studies will elucidate the role of eotaxin in the process of ongoing acute heart transplant rejection.

Exogenous gonadotropins have little impact on follicular but considerable effect on serum cytokine concentrations – a comparison between Natural Cycle and stimulated IVF using a multiplexed assay platform

Introduction: Throughout follicular growth and subsequent corpus luteum formation the leukocyte number increases and follicular vascularisation changes. These processes are enhanced under exogenous stimulation with gonadotropins. Cytokines released by leukocytes contribute to further recruitment and vascularisation of the follicle, and they play an important role in regulating ovarian steroidogenesis by influencing theca and granulosa–lutein cell function. Changes in cytokine and vascular endothelial growth factor (VEGF) concentrations in the ovary as a consequence of gonadotropin stimulation may negatively influence oocyte quality. In this project we have compared the intrafollicular production of inflammatory cytokines and growth factors between natural IVF cycles (NC) and classical, gonadotropin-stimulated IVF cycles (gsIVF). Material and Methods: Serum on the day of oocyte retrieval and follicular fluid (FF) were collected in 37 NC and 39 gsIVF cycles. Thirteen women within this population underwent one NC and one gsIVF cycle each. A total of 14 cytokines from Bio-Plex panels I and II were determined in matched serum and FF samples using Luminex xMAP technology on the Bio-Plex(R) platform, using the serum protocol. Results: Tumour necrosis factor-alpha, RANTES, eotaxin and interferon-gamma-induced protein-10 levels were lower in FF than in serum, and thus not further investigated. Interleukin (IL)-6, -8, -10, -15, -18, monocyte chemotactic protein-1 (MCP-1), VEGF and leukaemia inhibitory factor (LIF) showed higher median concentrations in FF than in serum, indicating possible ovarian production. Moreover, most of these showed higher evels in the gsIVF than in the NC groups in the serum, but not in the follicular fluid. IL-8 was reduced in gsIVF cycles. Conclusion: The fact that serum but not FF levels of the studied cytokines were higher in the stimulated than in the natural cycles can be attributed to the increased number of active follicles present after controlled ovarian stimulation.

Functional expression of CCR1, CCR3, CCR4, and CXCR4 chemokine receptors on human platelets

Platelets are known to contain platelet factor 4 and beta-thromboglobulin, alpha-chemokines containing the CXC motif, but recent studies extended the range to the beta-family characterized by the CC motif, including RANTES and Gro-alpha. There is also evidence for expression of chemokine receptors CCR4 and CXCR4 in platelets. This study shows that platelets have functional CCR1, CCR3, CCR4, and CXCR4 chemokine receptors. Polymerase chain reaction detected chemokine receptor messenger RNA in platelet RNA. CCR1, CCR3, and especially CCR4 gave strong signals; CXCR1 and CXCR4 were weakly positive. Flow cytometry with specific antibodies showed the presence of a clear signal for CXCR4 and weak signals for CCR1 and CCR3, whereas CXCR1, CXCR2, CXCR3, and CCR5 were all negative. Immunoprecipitation and Western blotting with polyclonal antibodies to cytoplasmic peptides clearly showed the presence of CCR1 and CCR4 in platelets in amounts comparable to monocytes and CCR4 transfected cells, respectively. Chemokines specific for these receptors, including monocyte chemotactic protein 1, macrophage inflammatory peptide 1alpha, eotaxin, RANTES, TARC, macrophage-derived chemokine, and stromal cell-derived factor 1, activate platelets to give Ca(++) signals, aggregation, and release of granule contents. Platelet aggregation was dependent on release of adenosine diphosphate (ADP) and its interaction with platelet ADP receptors. Part, but not all, of the Ca(++) signal was due to ADP release feeding back to its receptors. Platelet activation also involved heparan or chondroitin sulfate associated with the platelet surface and was inhibited by cleavage of these glycosaminoglycans or by heparin or low molecular weight heparin. These platelet receptors may be involved in inflammatory or allergic responses or in platelet activation in human immunodeficiency virus infection.

The chemokines CCL11, CCL20, CCL21, and CCL24 are preferentially expressed in polarized human secondary lymphoid follicles

Chemokines regulate cellular trafficking to and from lymphoid follicles. Here, the distribution pattern of four CCL chemokines is defined by in situ hybridization in human lymphoid follicles from tonsils and lymph nodes (LNs) of newborns and adults. Cells expressing CCL11 (eotaxin) and CCL20 (Exodus) were preferentially located within follicles, while cells expressing CCL21 (secondary lymphoid-tissue chemokine) and CCL24 (eotaxin-2) mRNA were almost exclusively found in the perifollicular areas. Hence, the two CCR3-binding chemokines, CCL11 and CCL24, showed a mutually exclusive expression pattern in the intra- and extra-follicular areas, respectively. Chemokine gene expression paralleled follicular maturation: in tonsils, where approximately 80% of follicles are polarized, CCL11 and CCL20 mRNA-positive cells were detected more frequently than in lymph nodes from adults, where about half of follicles are non-polarized. No intrafollicular chemokine expression was detectable in the primary follicles from newborns. Extrafollicular cells expressing CCL21 and CCL24 were again more frequent in tonsils than in LNs from adults. The observed preferential presence of cells expressing CC chemokines in polarized human lymphoid follicles indicates that chemokines are not only instrumental in the induction of follicle formation, but may also be involved in their further differentiation.

Serum but not follicular fluid cytokine levels are increased in stimulated versus natural cycle IVF: a multiplexed assay study.

Throughout follicular growth the number of immune cells increases, enhanced under stimulation with exogenous gonadotropins. This treatment, however, may adversely influence folliculogenesis and negatively affect oocyte quality through modifications in the follicular concentrations of cytokines released by these immune cells. We studied this hypothesis by systematically analysing the concentrations of cytokines present in the serum and follicular fluid at the time of follicular aspiration in conventional gonadotropin-stimulated (c-IVF) cycles in comparison with natural cycle IVF (NC-IVF) in which the follicles were naturally matured. Our study involved 37 NC-IVF and 39 c-IVF cycles including 13 women who underwent both therapies. Mean age was 35.3 ± 4.6 (SD) and 34.2 ± 3.7 years in the NC-IVF and c-IVF groups (ns). Thirteen cytokines were determined in matched serum and FF samples. Interleukin (IL)-4, TNF-α, RANTES, eotaxin and interferon-gamma-induced protein-10 concentrations were lower in FF than in serum. IL-6, -8, -10, -18, monocyte chemotactic protein-1 (MCP-1), VEGF and leukaemia inhibitory factor (LIF) showed higher median levels in FF than in serum, indicating possible ovarian production. Most of these markers were also increased in concentration in the stimulated (c-IVF) than in the NC groups in the serum, but not in the follicular fluid. This finding can be attributed to the increased number of active follicles present after controlled ovarian stimulation. IL-8 was reduced in c-IVF cycles. Our study did not reveal differences in follicular fluid but in serum cytokine concentrations, suggesting that the follicular immune system might not be significantly affected by gonadotropin stimulation.

A new eosinophilic esophagitis (EoE)-like disease without tissue eosinophilia found in EoE Families

BACKGROUND Eosinophilic esophagitis (EoE) is a rapidly emerging, chronic inflammatory, genetically impacted disease of the esophagus, defined clinically by symptoms of esophageal dysfunction and, pathologically, by an eosinophil-predominant tissue infiltration. However, in four EoE-families, we have identified patients presenting with EoE-typical and corticosteroid-responsive symptoms, but without tissue eosinophilia. It was the aim of this study to clinically and immunologically characterize these patients with EoE-like disease. METHODS Five patients suffering from an EoE-like disease were evaluated with endoscopic, histologic, functional and quantitative immunohistologic examinations, and mRNA expression determination. RESULTS The frequency of first generation offspring of EoE-like disease patients affected by EoE or EoE-like disease was 40%. Immunofluorescence analysis confirmed an almost complete absence of eosinophils in the esophageal tissues of patients with EoE-like disease, but revealed a considerable T cell infiltration, comparable to EoE. In contrast to EoE, eotaxin-3 mRNA and protein were markedly reduced in EoE-like disease (P < 0.05). The mRNA expression levels of three selected EoE genes (eotaxin-3, MUC4 and CDH26) allowed to discriminate between EoE-like disease, EoE and normal epithelium. CONCLUSIONS Patients suffering from "EoE without eosinophilia" do not fulfill formally the diagnostic criteria for EoE. However, their clinical manifestation, immunohistology and gene-expression pattern, plus the fact that they bequeath EoE to their offspring, suggest a uniform underlying pathogenesis. Conventional EoE, with its prominent eosinophilia, therefore appears to be only one phenotype of a broader "inflammatory dysphagia syndrome" spectrum. In this light, the role of the eosinophils, the definition of EoE, and its diagnostic criteria must likely be reconsidered. This article is protected by copyright. All rights reserved.