Modulation of eotaxin-3 (CCL26) in alveolar type II epithelial cells

Airway epithelial inflammation associated with emphysema, chronic bronchitis, chronic obstructive pulmonary disease (COPD) and asthma is regulated in part by alveolar type II cell chemokine signaling. Data suggest that resident lung cells use CCR3, CCR5 and CCR2 chemokine receptor/ligand systems to regulate the profile of leukocytes recruited in disease-associated inflammatory conditions. Thus studies were designed to test whether alveolar type II cells possess a Th1-activated CCR5-ligand system that modulates the Th2-activated CCR3/eotaxin-2 (CCL24), eotaxin-3 (CCL26) chemokine systems. The A549 alveolar type II epithelial-like cell culture model was used to demonstrate that alveolar type II cells constitutively express CCR5 which may be upregulated by MIP-1alpha (CCL3) whose expression was induced by the Th1 cytokines IL-1beta and IFN-gamma. Selective down-regulation of CCL26, but not CCL24, was observed in CCL3 and IL-4/CCL3 stimulated cells. Down-regulation was reversed by anti-CCR5 neutralizing antibody treatment. Thus, one mechanism through which Th1-activated CCCR5/ligand pathways modulate Th2-activated CCR3/ligand pathways is the differential down-regulation of CCL26 expression. Results suggest that the CCR3 and CCR5 receptor/ligand signaling pathways may be important targets for development of novel mechanism-based adjunctive therapies designed to abrogate the chronic inflammation associated with airway diseases.

CC chemokines and protective immunity: insights gained from mother-to-child transmission of HIV

Maternal-infant transmission provides a useful model for the study of immune factors associated with protection against the acquisition of human immunodeficiency virus and has emphasized the importance of CCL3 in protective immunity to this virus.

Immunity against breast cancer by TERT DNA vaccine primed with chemokine CCL21

Human telomerase reverse transcriptase (TERT) has been considered a potential tumor-associated antigen for active-specific immunotherapy. However, effective specific tumor antigen-specific immunity has been difficult to induce consistently by various TERT vaccine formulations. New adjuvant strategies have been employed, such as utilizing chemokines to attract T cells and antigen-presenting cells. Chemokine adjuvant strategies may enhance tumor antigen-specific immunity induced by vaccines. Therefore, we utilized chemokine ligand 21 (CCL21) as an adjuvant with a xenogeneic TERT DNA vaccine to induce tumor antigen-specific immunity against TERT-expressing breast cancer. The TERT DNA vaccine consisted of a plasmid containing the COOH terminal end of the TERT (cTERT) gene, encapsulated in multilayered liposomes with hemagglutinating virus of Japan coating. We demonstrated that CCL21 treatment before cTERT DNA vaccine, given intramuscularly, induced significantly higher anti-TERT specific cell-mediated immunity compared to cTERT DNA vaccine alone. Effective tumor antigen-specific immunity was shown both in prophylactic and therapeutic regimens against TS/A murine breast cancer. The study demonstrated that CCL21 administration before cTERT DNA vaccination significantly augmented tumor antigen-specific immunity against breast cancer.

Influence of heat stress on human monocyte-derived dendritic cell functions with immunotherapeutic potential for antitumor vaccines

Mild heat stress can modulate the activities of immune cells, including dendritic cells (DC) and theoretically, would constitute an innovative approach capable of enhancing the antitumor functions of DC. Therefore, we tested the effects of mild heat stress on the physiology and viability of human monocyte-derived DC, the major type of DC used in tumor immunotherapy trials. We first designed a heat-stress protocol consisting of repetitive, sublethal heat shocks throughout the generation of DC. Using this protocol, we observed that heat stress did not perturb the morphology and the phenotype of immature or mature DC or the capacities of immature DC to uptake antigens efficiently. It is noteworthy that in response to heat stress, mature DC produced higher levels of IL-12p70 and TNF-alpha, which are two cytokines involved in the stimulation of inflammatory reaction, whereas IL-10 production remained low. After heat-stress exposure, mature DC have the full ability to stimulate naive T cells with Th1 response polarization (high IFN-gamma and low IL-4 production) in an allogeneic MLR. It is interesting that heat stress enhanced the migratory capacities of DC in response to MIP-3beta/CCL19. Finally, heat stress partly protected DC from apoptosis induced by cytokine withdrawal. Overall, these findings validate the feasibility of improving immune response by heating human monocyte-derived DC and provide a strong rationale for using mild heat stress in combination with DC vaccination to increase antitumor response.

The strength of the chemotactic response to a CCR5 binding chemokine is determined by the level of cell surface CCR5 density

We have shown that the intensity of expression of the C-C chemokine receptor CCR5 at the single CD4(+) cell level strongly determines the efficiency of its function as a coreceptor for human immunodeficiency virus type 1. By analogy, we examined if the number of CCR5 molecules at the cell surface might determine its chemotactic response to CCR5 ligands. To test this hypothesis, we measured by flow cytometry the migration of primary human T cells towards the CCR5-binding chemokine CCL5 in vitro. First, we observed a dose-dependent blockage of this migration exerted by an anti-CCR5 monoclonal antibody. Second, we sorted peripheral blood mononuclear cells into five subpopulations expressing various cell surface CCR5 densities, and observed a correlation between the intensity of migration towards CCL5 and the level of CCR5 expression on these subpopulations. Third, we transduced CCR5(+) peripheral blood mononuclear cells with the CCR5 gene, and observed that the CCR5 over-expression induced an over-migration towards CCL5. Finally, we observed in healthy donors a correlation between the chemotactic response of peripheral blood CD8(+) T cell to CCL5 and their level of surface CCR5 expression. T-cell surface CCR5 density, which is constant over time for a given individual, but varies drastically among individuals, might therefore be an important personal determinant of T-cell migration in many biological situations where CCR5-binding chemokines play a role, such as graft rejection, T helper 1-mediated auto-immune diseases, and infectious diseases involving CCR5. Moreover, our data highlight the therapeutic potential of CCR5 antagonists in these situations.

The biology of the Gaucher cell: the cradle of human chitinases

Gaucher disease (GD) is the most common lysosomal storage disorder and is caused by inherited deficiencies of glucocerebrosidase, the enzyme responsible for the lysosomal breakdown of the lipid glucosylceramide. GD is characterized by the accumulation of pathological, lipid laden macrophages, so-called Gaucher cells. Following the development of enzyme replacement therapy for GD, the search for suitable surrogate disease markers resulted in the identification of a thousand-fold increased chitinase activity in plasma from symptomatic Gaucher patients and that decreases upon successful therapeutic intervention. Biochemical investigations identified a single enzyme, named chitotriosidase, to be responsible for this activity. Chitotriosidase was found to be an excellent marker for lipid laden macrophages in Gaucher patients and is now widely used to assist clinical management of patients. In the wake of the identification of chitotriosidase, the presence of other members of the chitinase family in mammals was discovered. Amongst these is AMCase, an enzyme recently implicated in the pathogenesis of asthma. Chitinases are omnipresent throughout nature and are also produced by vertebrates in which they play important roles in defence against chitin-containing pathogens and in food processing.

Expression of Toll-like receptors, interleukin 8, macrophage migration inhibitory factor, and osteopontin in tissues from pigs challenged with Salmonella enterica serovar Typhimurium or serovar Choleraesuis

Two serovars of Salmonella enterica, namely serovar Typhimurium (ST) and serovar Choleraesuis (SC) account for the vast majority of clinical cases of swine salmonellosis worldwide. These serovars are thought to be transmitted among pigs in production settings mainly through fecal-oral routes. Yet, few studies have evaluated effects of these serovars on expression of innate immune targets when presented to pigs via repeated oral dosing in an attempt to model transmission in production settings. Thus, a primary objective of the current experiments was to evaluate expression of Toll-like receptors (TLR) and selected chemoattractive mediators (interleukin 8, IL8; macrophage migration inhibitory factor, MIF; osteopontin, OPN) in tissues from pigs exposed to ST or SC that had been transformed with kanamycin resistance and green (STG) or red (SCR) fluorescent protein to facilitate isolation from pen fecal samples. In vitro studies confirmed that STG and SCR largely (though not completely) retained their ability to upregulate IL8 and CC chemokine ligand 20 (CCL20) in cultured swine jejunal epithelial cells. Transformed bacteria were then fed to pigs in an in vivo study to determine tissue specific effects on mRNA relative expression. Pigs were fed cookie dough inoculated with bacteria on days 0, 3, 7, and 10 with 10(8)CFU STG (n=8) or SCR (n=8), while control (CTL) pigs (n=8) received dough without bacteria. Animals were sacrificed 14 days from the initial bacterial challenge and samples of tonsil, jejunum, ileum, colon, mesenteric lymph node (MLN), spleen, and liver were removed for subsequent RNA isolation. Expression of mRNA in tissues was determined using real-time quantitative PCR and expressed relative to 18S rRNA. Within CTL pigs, when expressed relative to the content in liver, mRNA for all targets demonstrated substantial tissue effects (P<0.001 for all TLR; MIF, and OPN; P<0.05 for IL8). Feeding STG and SCR resulted in significant (P<or=0.05) tissue specific effects for TLR5, TLR9, IL8, MIF and OPN. However, aside from STG stimulated increase in IL8 in MLN (approximately 10-fold increase relative to CTL; P<0.05), significant changes in other molecular targets were generally less than one-fold. Results suggest that transformed bacteria may be useful in modeling chronic oral exposure of pigs to economically important salmonellae serovars. However, although statistically significant effects of bacterial feeding were observed in selected tissues for some targets, most changes in mRNA were generally incremental in magnitude.

Delivery of CCL21 to metastatic disease improves the efficacy of adoptive T-cell therapy

Adoptive T-cell transfer has achieved significant clinical success in advanced melanoma. However, therapeutic efficacy is limited by poor T-cell survival after adoptive transfer and by inefficient trafficking to tumor sites. Here, we report that intratumoral expression of the chemokine CCL21 enhances the efficacy of adoptive T-cell therapy in a mouse model of melanoma. Based on our novel observation that CCL21 is highly chemotactic for activated OT-1 T cells in vitro and down-regulates expression of CD62L, we hypothesized that tumor cell-mediated expression of this chemokine might recruit, and retain, adoptively transferred T cells to the sites of tumor growth. Mice bearing metastatic tumors stably transduced with CCL21 survived significantly longer following adoptive T-cell transfer than mice bearing non-CCL21-expressing tumors. However, although we could not detect increased trafficking of the adoptively transferred T cells to tumors, tumor-expressed CCL21 promoted the survival and cytotoxic activity of the adoptively transferred T cells and led to the priming of antitumor immunity following T-cell transfer. To translate these observations into a protocol of real clinical usefulness, we showed that adsorption of a retrovirus encoding CCL21 to OT-1 T cells before adoptive transfer increased the therapeutic efficacy of a subsequently administered dose of OT-1 T cells, resulting in cure of metastatic disease and the generation of immunologic memory in the majority of treated mice. These studies indicate a promising role for CCL21 in enhancing the therapeutic efficacy of adoptive T-cell therapy.

DCs metabolize sunlight-induced vitamin D3 to 'program' T cell attraction to the epidermal chemokine CCL27

During adaptive immune responses, dendritic cells activate T cells and endow them with specific homing properties. Mechanisms that 'imprint' specific tropisms, however, are not well defined. We show here that 1,25(OH)(2)D(3), the active form of vitamin D3, signaled T cells to express CC chemokine receptor 10, which enabled them to migrate to the skin-specific chemokine CCL27 secreted by keratinocytes of the epidermis. In contrast, 1,25(OH)(2)D(3) suppressed the gut-homing receptors alpha4beta7 and CCR9. Vitamin D3, the inactive prohormone naturally generated in the skin by exposure to the sun, was processed by dendritic cells and T cells to the active metabolite, providing a mechanism for the local regulation of T cell 'epidermotropism'. Our findings support a model in which dendritic cells process and 'interpret' locally produced metabolites to 'program' T cell homing and microenvironmental positioning.

Expression of mucosal chemokines TECK/CCL25 and MEC/CCL28 during fetal development of the ovine mucosal immune system

CCL25/TECK and CCL28/MEC are CC chemokines primarily expressed in thymic dendritic cells and mucosal epithelial cells. The cognate receptors of CCL25 and CCL28, CCR9 and CCR10, respectively, are mainly expressed on T and B lymphocytes. In human, mouse and pig, CCL25 and CCL28 play a key role in the segregation and the compartmentalization of the mucosal immune system through recruitment of immune cells to specific locations. However, little is known about their role in the ontogeny of the mucosal immune system during fetal development. In the present paper, we report the cloning and the sequencing of ovine CCL25, CCL28, CCR9 and CCR10 and the subsequent assessment of their mRNA expression by q-polymerase chain reaction in several tissues, including thymus, gut-associated lymphoid tissue and mammary gland, from young and adult sheep and in the fetal lamb during the development of the immune system. CCL25 mRNA was highly expressed in thymus and gut while CCL28 mRNA was more expressed in large intestine, trachea, tonsils and mammary gland, especially at the end of gestation. These results are consistent with observations in other species suggesting similar roles for these chemokines in sheep. In fetuses, mRNA of CCL25, CCL28 and their receptors are expressed early in the thymus and mucosal tissues, including the small intestine and the nasal mucosa. Furthermore, their expression increased towards the end of gestation. Consequently, we hypothesize that CCL25 and CCL28 play an important role in the lymphocyte colonization of fetal tissues, enabling the development of a functional immune system.

Cotransduction of CCL27 gene can improve the efficacy and safety of IL-12 gene therapy for cancer

Interleukin-12 (IL-12) is a potent antitumoral cytokine, but high doses are toxic. Herein, we demonstrate that combinational transduction of IL-12 and CC-chemokine ligand-27 (CCL27) genes into pre-existing murine OV-HM ovarian carcinoma and Meth-A fibrosarcoma, by using RGD fiber-mutant adenoviral vectors, could induce tumor regression and relieve systemic side effects more effectively than either treatment alone. The antitumor activity of the IL-12 and CCL27 combination treatment was T-cell-dependent, and development of long-term specific immunity was confirmed in rechallenge experiments. Immunohistochemical analysis of tumors transduced with CCL27 gene alone or cotransduced with IL-12 and CCL27 genes showed significant increases in numbers of infiltrating CD3(+) T cells, which included both CD4(+) and CD8(+) cells. Additionally, cotransduction with IL-12 and CCL27 genes could more efficiently activate tumor-infiltrating immune cells than transduction with CCL27 alone, as determined by the frequency of perforin-positive cells and expression levels of IFN-gamma. Furthermore, mice treated with the IL-12 and CCL27 combination compared with those treated with IL-12 alone showed milder pathological changes, for example, lymphocyte infiltration and extramedullary hematopoiesis, in lung, liver and spleen. Our data provide evidence that combinational in vivo transduction with IL-12 and CCL27 genes is a promising approach for the development of cancer immunogene therapy that can simultaneously recruit and activate tumor-infiltrating immune cells.

[From discovery to innovation: the example of hypereosinophilic syndrome]

Biomedical research is extremely productive so that each day new discoveries reveal novel (mechanisms and) molecular pathways of diseases. However, the number of innovative therapies approved each year by regulatory authorities is decreasing. The causes of this "innovation breakdown" are multiple and should be explored both in academic institutions and in the industrial world. New initiatives are underway in the Walloon Region to improve this situation, such as the setting up of the BioWin Health Cluster gathering pharmaceutical and biotechnology enterprises and university laboratories. This new vision of the partnership between academia and the private sector should be based on strong fundamental research activities. We illustrate this concept by discussing recent advances in the diagnosis and treatment of the hypereosinophilic syndrome.

MSC–DC interactions: MSC inhibit maturation and migration of BM-derived DC

BACKGROUND

Mesenchymal stromal cells (MSC) comprise one of the BM stromal cells that are known to support hematopoiesis. It has also been suggested recently that MSC display immunosuppressive capacities through inhibiting the differentiation of monocyte-derived DC. DC travel to the lymph nodes (LN) to present Ag to T cells, and CCL21 is the chemokine that plays an important role in DC migration into the T-cell area of LN. We addressed the effect of MSC on this chemotactic activity of DC, one of the typical characteristics upon maturation.

METHODS

BM cells were isolated and then cultured for generation of myeloid DC in the presence of GM-CSF and/or lipopolysaccharide with or without MSC. MSC were identified by flow cytometry of the immunologic markers and by performing colony-forming unit fibroblast assay. Migration of DC was observed with a newly developed time-lapse video microscopic technique.

RESULTS

MSC co-culture inhibited the initial differentiation of DC, as well as their maturation. The matured DC actively migrated directionally in response to CCL21, a powerful DC-attracting chemokine, whereas the MSC co-cultured DC did not.

DISCUSSION

Collectively, the findings of these experiments raise the possibility that MSC suppress the migratory function of DC and so they may serve immunoregulatory activities through the modulation of the Ag-presenting function of DC.

Stimulation of the In Vitro Migration of Ovine Eosinophils by Factors Derived from the Sheep Scab Mite, Psoroptes ovis

The ectoparasitic astigmatid mite Psoroptes ovis causes sheep scab, a highly contagious, severe allergic dermatitis associated with damage to the fleece and hide, loss of condition and occasional mortality. The scab lesion is characterized by a massive infiltration of eosinophils that begins very rapidly after infection. This paper reports the finding that mite-derived factors directly enhance the migration of ovine eosinophils in vitro. Significant (p < 0.01) and dose-dependent (r = 0.972 +/- 0.018 (SD)) activity was initially identified in whole mite extracts, by comparison with medium controls in an assay based on modified Boyden chambers and ovine bone marrow target cells. Similar pro-migratory activity (p < 0.005; r = 0.928 +/- 0.069 (SD)) was detected in washes containing mite excretory/secretory material. By direct comparison with migration ratios (n = 3) for defined chemotactic (rmeotaxin = 3.430 +/- 0.360 (SD)) and chemokinetic (rminterleukin-5 = 0.982 +/- 0.112 (SD)) stimuli it was determined that the activity in both mite extracts (0.992 +/- 0.038 (SD)) and mite washes (0.969 +/- 0.071 (SD)) was chemokinetic. Subsequent experiments (n = 3) in which live mites were incorporated directly into the in vitro assay system indicated that they produced factors that significantly (p < 0.001) enhanced eosinophil migration to a degree directly related to mite numbers (r = 0.993 +/- 0.005 (SD)). The identity of the factor(s) responsible is uncertain, but their presence suggests that mites may be capable of directly activating eosinophils in vivo, and raises the possibility that mites could directly influence, perhaps even initiate, the rapid early tissue eosinophilic response observed in experimental sheep scab infections.

Effects of Salmonella enterica serovar Typhimurium, or serovar Choleraesuis, Lactobacillus reuteri and Bacillus licheniformis on chemokine and cytokine expression in the swine jejunal epithelial cell line, IPEC-J2

Direct-fed microbials, including Lactobacillus and Bacillus spp., are potential replacements for low dose in-feed antibiotics for swine and other livestock. To understand the function of these microbes in the gut, the current study used pig jejunal epithelial cells (IPEC-J2) to evaluate how Lactobacillus reuteri (LR) and Bacillus licheniformis (BL) differed from Salmonella enterica serovars Typhimurium (ST) or Choleraesuis (SC) in their ability to regulate, stimulate, or modify the proinflammatory mediators, interleukin 8 (IL8), CC chemokine 20 (CCL20), and tumor necrosis factor-alpha (TNFalpha). To optimize the positive control to drive IL8 secretion by IPEC-J2 cells, cells were treated apically with various concentrations of ST (versus control (CTL)) for 1h, followed by a wash. Media containing gentamicin was added and collected at 6h post-treatment. Compared to CTL, 10(8) ST produced maximal IL8 secretion in both the apical and basolateral directions, with significant basolateral polarization (P<0.0001). We next evaluated the time course of IL8 secretion, and IL8, CCL20, and TNFalpha mRNA expression by IPEC-J2 cells treated apically with 10(8) ST, SC, LR, and BL versus CTL. Media and RNA were collected at 1.5, 3.0, and 6.0 h post treatment. Only ST stimulated an increase in IL8 secretion at any time point, with increases in IL8 mRNA at both 3 and 6h (P<0.05). However, BL increased IL8 mRNA at 1.5h (P<0.0001). Neither LR nor SC affected IL8 mRNA expression. CCL20 mRNA was strongly upregulated by ST (P<0.05) and BL (1.5 and 3.0 h; P<0.05), but not LR or SC. Only ST increased TNFalpha mRNA relative to CTL (P<0.05). Two experiments were conducted to determine if pre-exposure of IPEC-J2 cells to LR or BL modified ST induced IL8 secretion. Confluent cells were treated apically overnight with various levels of LR or BL (in separate experiments) followed by ST challenge. Media were collected at 4 (LR experiment) or 5h (BL experiment) post ST. In the LR study, IL8 secretion was increased by ST as compared to CTL (P<0.0001), reduced by LR (P<0.05), and LR+ST co-treatments failed to alter ST stimulated secretion. In the BL experiment, secretion of IL8 was increased by ST (P<0.0001), but blunted basolaterally in BL+ST co-treated wells. The data demonstrate that IPEC-J2 cells increase IL8 secretion in response to ST, and IL8 mRNA in response to ST and BL, but not LR. Furthermore, ST stimulated secretion of IL8 is inhibited basolaterally in the presence of BL.

Modulation of cytokine secretion by pentacyclic triterpenes from olive pomace oil in human mononuclear cells

Olive pomace oil, also known as "orujo" olive oil, is a blend of refined-pomace oil and virgin olive oil, fit for human consumption. Maslinic acid, oleanolic acid, erythrodiol, and uvaol are pentacyclic triterpenes, found in the non-glyceride fraction of orujo oil, which have previously been reported to have anti-inflammatory properties. In the present work, we investigated the effect of these minor components on pro-inflammatory cytokine production by human peripheral blood mononuclear cells in six different samples. Uvaol, erythrodiol, and oleanolic acid significantly decreased IL-1beta and IL-6 production in a dose-dependent manner. All three compounds significantly reduced TNF-alpha production at 100microM; however, at 10microM, uvaol and oleanolic acid enhanced the generation of TNF-alpha. In contrast, maslinic acid did not significantly alter the concentration of those cytokines, with the exception of a slight inhibitory effect at 100microM. All four triterpenes inhibited production of I-309, at 50microM and 100microM. However, uvaol enhanced I-309 production at 10microM. The triterpenic dialcohols had a similar effect on MIG production. In conclusion, this study demonstrates that pentacyclic triterpenes in orujo oil exhibit pro- and anti-inflammatory properties depending on chemical structure and dose, and may be useful in modulating the immune response.

Fever-range thermal stress promotes lymphocyte trafficking across high endothelial venules via an interleukin 6 trans-signaling mechanism

Fever is an evolutionarily conserved response during acute inflammation, although its physiological benefit is poorly understood. Here we show thermal stress in the range of fever temperatures increased the intravascular display of two 'gatekeeper' homing molecules, intercellular adhesion molecule 1 (ICAM-1) and CCL21 chemokine, exclusively in high endothelial venules (HEVs) that are chief portals for the entry of blood-borne lymphocytes into lymphoid organs. Enhanced endothelial expression of ICAM-1 and CCL21 was linked to increased lymphocyte trafficking across HEVs. A bifurcation in the mechanisms controlling HEV adhesion was demonstrated by evidence that the thermal induction of ICAM-1 but not of CCL21 involved an interleukin 6 trans-signaling pathway. Our findings identify the 'HEV axis' as a thermally sensitive alert system that heightens immune surveillance during inflammation by amplifying lymphocyte trafficking to lymphoid organs.

Inflammation but not oxidative stress is associated with beta-chemokine levels and prevalence of cardiovascular disease in uraemic patients

Inflammation and oxidative stress (SOX) have been reported in patients with chronic renal failure (CRF), but their influence on beta-chemokines levels and cardiovascular disease (CVD) prevalence remains unknown. We assessed beta-chemokines, SOX markers and high sensitivity C-reactive protein (hs CRP) as a marker of inflammation in 40 uraemic patients, both with as well as without CVD and 20 controls. Compared with the controls, the patients with CVD showed a significant increase in plasma concentrations of monocyte chemoattractant protein-1 (MCP-1), total peroxide (both p<0.05), macrophage inflammatory protein 1beta (MIP-1beta) and hs CRP (both p<0.01). The values of MCP-1 and hs CRP were more elevated in patients with CVD than without CVD (p<0.01 and p<0.05; respectively). Both subgroup of CRF patients were lower of regulated upon activation, normal T cell expressed and secreted (RANTES) levels than in the controls (both p<0.001). The positive relationships were between hs CRP and presence of CVD, MIP-1beta (both p<0.01) and MCP-1 levels (p<0.05). SOX markers did not show any significant correlation with beta-chemokines, hs CRP and presence of CVD. We documented that increased inflammation but not SOX were associated with significant elevation in plasma beta-chemokines levels and CVD prevalence in CRF patients not requiring dialysis.

Cigarette smoke-induced pulmonary inflammation and emphysema are attenuated in CCR6-deficient mice

Chronic obstructive pulmonary disease (COPD) is mainly caused by cigarette smoking, and is characterized by an increase in inflammatory cells in the airways and pulmonary tissue. The chemokine receptor CCR6 and its ligand MIP-3alpha/CCL20 may be involved in the recruitment of these inflammatory cells. To investigate the role of CCR6 in the pathogenesis of COPD, we analyzed the inflammatory responses of CCR6 knockout (KO) and wild-type mice upon cigarette smoke (CS) exposure. Both subacute and chronic exposure to CS induced an increase in cells of the innate and adaptive immune system in the bronchoalveolar lavage, both in CCR6 KO and wild-type mice. However, the accumulation of dendritic cells, neutrophils, and T lymphocytes, which express CCR6, was significantly attenuated in the CCR6 KO mice, compared with their wild-type littermates. In the lung tissue of CCR6 KO mice, there was an impaired increase in dendritic cells, activated CD8(+) T lymphocytes, and granulocytes. Moreover, this attenuated inflammatory response in CCR6 KO mice offered a partial protection against pulmonary emphysema, which correlated with an impaired production of MMP-12. Importantly, protein levels of MIP-3alpha/CCL20, the only chemokine ligand of the CCR6 receptor, and MCP-1/CCL2 were significantly increased upon CS exposure in wild-type, but not in CCR6 KO mice. In contrast, CCR6 deficiency had no effect on the development of airway wall remodeling upon chronic CS exposure. These results indicate that the interaction of CCR6 with its ligand MIP-3alpha contributes to the pathogenesis of CS-induced pulmonary inflammation and emphysema in this murine model of COPD.

A central regulatory role for eosinophils and the eotaxin/CCR3 axis in chronic experimental allergic airway inflammation

To clarify the role and regulation of eosinophils, we subjected several key eosinophil-related genetically engineered mice to a chronic model of allergic airway inflammation aiming to identify results that were independent of the genetic targeting strategy. In particular, mice with defects in eosinophil development (Deltadbl-GATA) and eosinophil recruitment [mice deficient in CCR3 (CCR3 knockout) and mice deficient in both eotaxin-1 and eotaxin-2 (eotaxin-1/2 double knockout)] were subjected to Aspergillus fumigatus-induced allergic airway inflammation. Allergen-induced eosinophil recruitment into the airway was abolished by 98%, 94%, and 99% in eotaxin-1/2 double knockout, CCR3 knockout, and Deltadbl-GATA mice, respectively. Importantly, allergen-induced type II T helper lymphocyte cytokine production was impaired in the lungs of eosinophil- and CCR3-deficient mice. The absence of eosinophils correlated with reduction in allergen-induced mucus production. Notably, by using global transcript expression profile analysis, a large subset (29%) of allergen-induced genes was eosinophil- and CCR3-dependent; pathways downstream from eosinophils were identified, including in situ activation of coagulation in the lung. In summary, we present multiple lines of independent evidence that eosinophils via CCR3 have a central role in chronic allergic airway disease.

A DNA vaccine encoding CCL4/MIP-1β enhances myocarditis in experimental Trypanosoma cruzi infection in rats

Chagas' disease, caused by Trypanosoma cruzi, is a major cause of cardiovascular disease in Latin America. Exacerbated inflammation disproportional to parasite load characterizes chronic myocardial lesions in chagasic patients. Chemokines and their receptors are expected to account for the renewed inflammatory processes after the inoculation of the parasite, but their potential unique functions are far from being clear. Herein, we evaluated the effect of a DNA vaccine encoding CCL4/MIP-1beta, a CC-chemokine, in T. cruzi-elicited myocarditis in rats. Holtzman rats were given intramuscularly cardiotoxin and the CCL4/MIP-1beta DNA-containing plasmid (100microg) was delivered in this muscular site four times. Fourteen days after last immunization, animals were inoculated with a myotropical CL-Brener T. cruzi clone. Peak of parasitism was observed at day 15 after infection, preceding the peak of myocardial inflammation at day 20. Myocarditis was still intense at day 30, but the inflammatory infiltrates showed a more focal distribution. The expression of CCL2/MCP-1 and CCL4/MIP-1beta correlated closely with the kinetics of myocardial inflammation. The CCL4/MIP-1beta DNA vaccine induced an increase of the levels of the anti-CCL4/MIP-1beta observed in T. cruzi-infected animals. This was associated with an exacerbation of myocardial inflammation and fibrosis, although alterations in parasitemia and myocardial parasitism were not observed. Our data suggest that CCL4/MIP-1beta plays a role in preventing excessive inflammation and pathology rather than in controlling parasite replication.

Induction of protective and therapeutic antitumour immunity using a novel tumour‐associated antigen‐specific DNA vaccine

DNA vaccination has become an attractive immunization strategy against cancer. However, a major problem of DNA vaccination is its limited potency to be taken up by the antigen-presenting cells. In contrast, loss of immunogenic epitopes of tumour cells has urged the development of vaccines against multiple epitopes. In this study, we developed a novel strategy for the APC to efficiently cross-present a fusion tumour antigen, which contains both MHC class I-restricted and class II-restricted T-cell epitopes from Her-2/neu and p53 in a cognate manner. The N-terminus of the fusion Her-2/neu, p53 protein was linked to the sequence encoding for human secondary lymphoid-tissue chemokine for secretion and chemokinesis, and the C-terminus of the fusion protein was linked to a cell-binding domain of IgG (Fc portion, the cell-binding domain of IgG) for receptor-mediated internalization. Here, we show that the introduction of fused-gene DNA vaccine by gene gun reduced the size of established tumours and prolonged the lifespan of tumour-bearing mice. Results show that this DNA vaccination strategy can broadly enhance the antigen-specific cellular and humoral immune responses. This vaccine is capable of inducing adaptive immunity and may provide a novel, generic design for the development of therapeutic and preventive DNA vaccines.

Membrane-bound eotaxin-3 mediates eosinophil transepithelial migration in IL-4-stimulated epithelial cells

Epithelial cells play an important role in orchestrating mucosal immune responses. In allergic-type inflammation, epithelial cells control the recruitment of eosinophils into the mucosa. Th2-type cytokine-driven release of eosinophil-active chemokines from epithelial cells directs eosinophil migration into the mucosal epithelium. CCR3, the main eosinophil chemokine receptor, regulates this process; however, the respective contribution of individual CCR3 ligands in eosinophil transepithelial migration is less well understood. Using an in vitro transepithelial chemotaxis system, we found that eotaxin-3 produced by IL-4-stimulated airway epithelial cells and CCR3 on eosinophils exclusively mediate eosinophil transepithelial migration. Eotaxin-3 protein levels were also increased in the nasal mucosal epithelium recovered from allergic patients as compared to non-allergic patients. Surprisingly, eotaxin-3 in IL-4-stimulated airway epithelial cells was predominantly cell surface bound, and the cell surface form was critical for eosinophil transepithelial migration. Eotaxin-3 cell surface association was partially glycosaminoglycan (GAG) dependent, but was completely protein dependent, suggesting that eotaxin-3 associates with both GAG and cell surface proteins. We thus provide evidence that cell surface-associated eotaxin-3 is the critical IL-4-dependent chemotactic signal mediating eosinophil transepithelial migration in the setting of allergic inflammation.

Inhibitory effects of fluvastatin on cytokine and chemokine production by peripheral blood mononuclear cells in patients with allergic asthma

BACKGROUND

Statins have anti-inflammatory effects on immune cells.

OBJECTIVE

To investigate the immunomodulatory effects of fluvastatin on peripheral blood mononuclear cells (PBMCs) after allergen-specific and non-allergen-specific stimulation in patients with asthma and in healthy subjects.

METHODS

PBMCs from seven patients with asthma who showed elevated immunoglobulin (Ig)E to house dust mite were isolated and stimulated with Dermatofagoides farinae, purified protein derivative, and phytohaemagglutinin (PHA) in the presence or absence of fluvastatin. PBMCs from seven healthy subjects were stimulated with PHA. The effects of fluvastatin on cell proliferation and production of cytokines (interferon [IFN]-gamma and interleukin [IL]-5) and chemokines (chemokine CXC motif, ligand [CXCL10], and CC chemokine ligand [CCL17]) were measured. Migration of T helper (Th)1 and Th2 cell lines was also investigated. The expression of CXCR3 and CCR4 was analysed with flow cytometry. Steroid-insensitive PBMCs induced by preculture with IL-2 and IL-4 were also evaluated. Some experiments were performed in the presence of mevalonic acid.

RESULTS

Fluvastatin inhibited the proliferation of PBMCs and decreased the production of IL-5, IFN-gamma, CCL17, and CXCL10 after allergen-specific and non-allergen-specific stimulation; all these effects, except for decreased CXCL10 production, were partially reversed by mevalonic acid. Culture supernatants obtained in the presence of fluvastatin prevented the migration of Th1 and Th2 cell lines in a dose-dependent manner. In addition, CCR4 and CXCR3 expression on CD4(+) T cells was not affected by the presence of fluvastatin. Fluvastatin inhibited the proliferative response of steroid-insensitive PBMCs to phytohaemagglutinin.

CONCLUSION

Fluvastatin has inhibitory effects on cytokine and chemokine production, and thus might be used as a potential therapeutic agent in severe asthma.

Echinococcus multilocularis metacestodes modulate cellular cytokine and chemokine release by peripheral blood mononuclear cells in alveolar echinococcosis patients

Infection with the cestode Echinococcus multilocularis causes human alveolar echinococcosis (AE), a life-threatening disease affecting primarily the liver. Despite the severity of AE, clinical symptoms often develop only many years after infection, which suggests that E. multilocularis has developed mechanisms which depress anti-parasite immune response, thus favouring immune evasion. In this study we examined the production of cytokines, chemokines and the expression of CD molecules on peripheral blood mononuclear cells (PBMC) from AE patients and healthy controls in response to E. multilocularis metacestode culture supernatant, viable E. multilocularis vesicles and E. multilocularis vesicle fluid antigen in vitro. After 48 h of co-culture, E. multilocularis metacestode culture supernatant and E. multilocularis vesicles depressed the release of the proinflammatory cytokine interleukin (IL)-12 by PBMC. This effect was dose-dependent and a suppression of tumour necrosis factor (TNF)-alpha and IL-12 was observed even when PBMC were activated with lipopolysaccharide (LPS). Comparing proinflammatory cytokine release by AE patients and controls showed that the release of IL-12 and TNF-alpha was reduced in AE patients, which was accompanied by an increased number of CD4+ CD25+ cells and a reduced release of the Th2 type chemokine CCL17 (thymus and activation regulated chemokine, TARC), suggesting an anti-inflammatory response to E. multilocularis metacestode in AE patients. Instead the production of interferon (IFN)-gamma and the expression of CD28 on CD4+ T cells were increased in PBMC from AE patients when compared to controls. This was accompanied by a higher release of the Th2-type chemokine CCL22 (macrophage derived chemokine, MDC) supporting that E. multilocularis also generates proinflammatory immune responses. These results indicate that E. multilocularis antigens modulated both regulatory and inflammatory Th1 and Th2 cytokines and chemokines. Such a mixed profile might be required for limiting parasite growth but also for reducing periparasitic tissue and organ damage in the host.