Follow-up of patients with systemic immunological diseases undergoing fatty-degenerative osteolysis of the jawbone surgery and treated with RANTES 27CH

Regulated-on-activation, normal T cell expressed and secreted (also called RANTES, CCL5 or R/C) is a chemotactic cytokine that plays a key role in recruiting immune cells to inflammatory sites. R/C is involved in the pathogenesis of many systemic immune-mediated diseases (SIDs) and is upregulated in fatty-degenerative osteolysis jawbone (FDOJ) cavitations. Surgical cleaning of degenerative areas reduces the source of chronic R/C but might not be sufficient to re-establish the altered immunological patterns. The aim of the present study was to collect clinical data from patients suffering from sids who underwent dental surgery of FDOJ areas (n=46), by measuring R/C serum levels at the first visit (V0) prior to surgery, and at the second visit (V1). The majority of patients (n=41) were treated one month with ultra-low dose RANTES (27CH), a medicine used in micro-immunotherapy, while five patients were not. Mean and standard deviation of R/C serum levels at V0 in treated and untreated patients were respectively 48.5±25.8ng/ml and 42.48±22.22ng/ ml. Untreated patients had a tendency towards higher R/C levels at V1 (68.36±30.7ng/ml; p=0.062), while an opposite tendency was observed in treated patients (40.9±20.3ng/ml; p=0.129). Investigators observed that a cut-off set at 40ng/ml at V0 seemed to be predictive of the efficacy of the dental surgery/treatment (p=0.0013, n=26) and that gender could influence R/C levels and patient's responsiveness. The Authors, being aware that this is a preliminary follow-up, wanted to lay the basis for forthcoming studies, in which a larger cohort of patients and well-defined inclusion/exclusion criteria will be established.

Critical role of the N-loop and beta1-strand hydrophobic clusters of RANTES-derived peptides in anti-HIV activity

HIV initiates its infectious cycle by docking to CD4 and a chemokine receptor, most commonly CCR5. RANTES, a natural CCR5 ligand, is a potent inhibitor of HIV-1. Despite the lack of structural information on the RANTES-CCR5 complex, determinants of HIV blockade were previously identified within the RANTES N-loop and beta1-strand regions. A prototype N-loop/beta1-strand peptide, named R11-29, contains two terminal hydrophobic stretches separated by a central hydrophilic region. Here, the role of the terminal hydrophobic clusters was investigated by means of amino acid substitutions or deletions. Most hydrophobic residues in these clusters were shown to be fundamental for the anti-HIV activity. However, increasing the hydrophobicity of the two clusters using non-natural amino acids did not significantly improve the potency of the peptides. These results may provide instrumental knowledge for the rational design of RANTES-derivative molecules with increased anti-HIV activity.

RANTES (CCL5) regulates airway responsiveness after repeated allergen challenge

RANTES (CC chemokine ligand 5) contributes to airway inflammation through accumulation of eosinophils, but the exact role of RANTES (CCL5) is not defined. C57BL/6 mice, sensitized by injection of ovalbumin (OVA) on Days 1 and 14, were challenged with OVA on Days 28, 29, and 30 (3 challenges, short-term-challenge model) or on Days 28, 29, 30, 36, 40, 44, and 48 (7 challenges, repeated-challenge model) and evaluated 48 h later. Anti-mouse RANTES was given intravenously, and recombinant mouse RANTES or PBS was given intratracheally. These reagents were given on Days 28, 29, and 30 in the short-term-challenge study and on Days 44 and 48 in the repeated-challenge study. After short-term challenge, there were no effects after administration of anti-RANTES or RANTES. In the repeated-challenge study, although control mice showed a decrease in airway hyperresponsiveness, administration of anti-RANTES sustained and enhanced airway hyperresponsiveness and increased goblet cell numbers. In contrast, administration of RANTES normalized airway function but reduced goblet cell numbers. IL-12 and IFN-gamma levels in BAL decreased in the anti-RANTES group and increased in the RANTES group. IFN-gamma-producing CD4 T cells in lung, and IFN-gamma production from lung T cells in response to OVA in the anti-RANTES group, were significantly decreased but were increased in the RANTES group. Anti-IFN-gamma, administered with RANTES, decreased the effects of RANTES on AHR after repeated challenge. These data indicate that RANTES plays a role in the regulation of airway function after repeated allergen challenge, in part through modulation of levels of IFN-gamma and IL-12.

Adenosine A2a receptors induce heterologous desensitization of chemokine receptors

Adenosine, released by cells in an injurious or hypoxic environment, possesses potent anti-inflammatory effects by inhibiting the production of proinflammatory cytokines and superoxide anions (O2-). We hypothesized that adenosine compounds also induced heterologous desensitization of chemokine receptors, which played a critical role in leukocyte trafficking. Our studies using adenosine receptor subtype-specific agonists revealed that pretreatment with adenosine compounds suppressed RANTES-induced chemotaxis and Ca2+ flux through activation of A2a adenosine receptor. Adenosine compounds also desensitized IL-8- and MCP-1-induced chemotaxis, but not that induced by fMLP. Activation of protein kinase A (PKA), a component of the signaling pathway induced by the A2a receptor, was sufficient to desensitize RANTES-induced chemotaxis. Inhibition of PKA reversed the desensitization effects of adenosine compounds, suggesting that PKA was necessary for A2a receptor-mediated heterologous desensitization. In a mouse model, prior activation of A2a receptors blocked RANTES-induced recruitment of leukocytes in an air pouch. Moreover, the A2a receptor-induced cross-desensitization also reduced the susceptibility of monocytes to infection by an R5 strain of HIV-1. Our results suggest that activation of A2a adenosine receptors suppresses chemokine receptor function, and such receptor cross-talk was based on the simple mechanism of PKA-mediated heterologous desensitization, thus contributing to the antiinflammatory activity of adenosine.

Intracisternal administration of chemokines facilitated formalin-induced behavioral responses in the orofacial area of freely moving rats

The present study investigated the effects of intracisternal administration of MCP-1, Rantes or IL-8 on pain transmission in the orofacial area. We also investigated mechanisms of hyperalgesic responses produced by intracisternal administration of IL-8. An orofacial formalin test was employed to assess the effects of chemokines on nociceptive processing. For each animal, the number of behavioral responses and the time spent grooming, rubbing and/or scratching the facial region proximal to the formalin injection site was recorded for nine successive 5-min intervals. Intracisternal administration of MCP-1, Rantes or IL-8 significantly increased formalin-induced scratching behavioral responses in the orofacial area. Intracisternal pretreatment with indomethacin, a non-selective cyclooxygenase inhibitor, did not block IL-8-induced hyperalgesia. Pretreatment with 100 microg propranolol, a non-selective beta-adrenergic receptor antagonist and 50 microg atenolol, a selective beta(1)-adrenergic receptor antagonist, inhibited the number of scratches and the duration of scratching produced by 1 ng of IL-8 injected intracisternally. These results indicate that intracisternal administration of chemokines produce a hyperalgesic response with an orofacial inflammatory pain model and that the IL-8-induced hyperalgesia is mediated by central beta(1)-adrenergic receptor.

Differential polarization of immune responses by co-administration of antigens with chemokines

Chemokines are key players in the elicitation of immune response, by selectively attracting subpopulations of immune cells to the site of antigen presentation. Therefore, they are natural candidates for modulating immune responses to antigens qualitatively and quantitatively. We have selected chemokines associated with different arms of the immune response, i.e. RANTES/CCL5, B-lymphocyte chemoattractant/CXCL13, and monocyte chemoattractant protein-1/CCL2, and co-injected DNA expression constructs encoding these chemokines with constructs encoding two HIV antigens, gp120 and gp160, in mice. We subsequently measured markers of both cellular and humoral immune responses, and found that these chemokines qualitatively influenced the outcome of immune responses to both antigens, essentially according to their predicted association to Th profiles. These results are relevant towards the engineering of novel vaccine and immune-based therapies, and point to chemokines as candidate adjuvant and immunomodulatory molecules.

Differential sensitivities of pyrogenic chemokine fevers to CC chemokine receptor 5 antibodies

Macrophage inflammatory protein (MIP)-1beta and RANTES (regulated on activation, normal T-cells expressed and secreted) are members of the CC-family of chemokines. Although these two peptides are structurally and functionally related to one another, each exhibits distinct features, which allows it to independently regulate specific aspects of the host inflammatory response. They evoked intense and functionally different febrile responses when applied directly on pyrogen-sensitive cells located in the in the preoptic area of the anterior hypothalamus (POA). The present experiments were carried out to test the central role of CCR5, a functional receptor for MIP-1beta and RANTES, in the febrile responses induced by these chemokines when injected directly into the POA. The microinjection of an equimolecular dose (50 pg) of either MIP-1beta or RANTES into the POA induced a rapid onset; monophasic fever in rats that persisted for a long period. The microinjection of 2.0 microg specific neutralizing antibodies against CCR5 (anti-CCR5) into the POA fails to affect the effects on body temperature induced by MIP-1beta. However, pretreatment with the same dose of anti-CCR5 suppressed the febrile response induced by RANTES given at the same site. The microinjection of control IgG or anti-CCR5 does not affect basal temperature, when administered alone at the same hypothalamic site. The present experiments show that hypothalamic CCR5 are functionally involved in the febrile response induced by RANTES, but not by MIP-1beta. They also suggest the existence of functionally different components in the presumptive primary locus of the thermoregulatory controller, in which both chemotactic cytokines, together other mediators, could play a relevant role in the complex process of fever pathogenesis.

Melatonin promoted chemotaxins expression in lung epithelial cell stimulated with TNF-alpha

BACKGROUND

Patients with asthma demonstrate circadian variations in the airway inflammation and lung function. Pinealectomy reduces the total inflammatory cell number in the asthmatic rat lung. We hypothesize that melatonin, a circadian rhythm regulator, may modulate the circadian inflammatory variations in asthma by stimulating the chemotaxins expression in the lung epithelial cell.

METHODS

Lung epithelial cells (A549) were stimulated with melatonin in the presence or absence of TNF-alpha(100 ng/ml). RANTES (Regulated on Activation Normal T-cells Expressed and Secreted) and eotaxin expression were measured using ELISA and real-time RT-PCR, eosinophil chemotactic activity (ECA) released by A549 was measured by eosinophil chemotaxis assay.

RESULTS

TNF-alpha increased the expression of RANTES (307.84 +/- 33.56 versus 207.64 +/- 31.27 pg/ml of control, p = 0.025) and eotaxin (108.97 +/- 10.87 versus 54.00 +/- 5.29 pg/ml of control, p = 0.041). Melatonin(10(-10) to 10(-6)M) alone didn't change the expression of RNATES (204.97 +/- 32.56 pg/ml) and eotaxin (55.28 +/- 6.71 pg/ml). However, In the presence of TNF-alpha (100 ng/ml), melatonin promoted RANTES (410.88 +/- 52.03, 483.60 +/- 55.37, 559.92 +/- 75.70, 688.42 +/- 95.32, 766.39 +/- 101.53 pg/ml, treated with 10(-10), 10(-9), 10(-8), 10(-7),10(-6)M melatonin, respectively) and eotaxin (151.95 +/- 13.88, 238.79 +/- 16.81, 361.62 +/- 36.91, 393.66 +/- 44.89, 494.34 +/- 100.95 pg/ml, treated with 10(-10), 10(-9), 10(-8), 10(-7), 10(-6)M melatonin, respectively) expression in a dose dependent manner in A549 cells (compared with TNF-alpha alone, P < 0.05). The increased release of RANTES and eotaxin in A549 cells by above treatment were further confirmed by both real-time RT-PCR and the ECA assay.

CONCLUSION

Taken together, our results suggested that melatonin might synergize with pro-inflammatory cytokines to modulate the asthma airway inflammation through promoting the expression of chemotaxins in lung epithelial cell.

Prevention of vaginal SHIV transmission in rhesus macaques through inhibition of CCR5

Topical agents, such as microbicides, that can protect against human immunodeficiency virus (HIV) transmission are urgently needed. Using a chimeric simian/human immunodeficiency virus (SHIV SF162), which is tropic for the chemokine receptor CCR5, we report that topical application of high doses of PSC-RANTES, an amino terminus-modified analog of the chemokine RANTES, provided potent protection against vaginal challenge in rhesus macaques. These experimental findings have potentially important implications for understanding vaginal transmission of HIV and the design of strategies for its prevention.

Interference with Heparin Binding and Oligomerization Creates a Novel Anti-Inflammatory Strategy Targeting the Chemokine System

A hallmark of autoimmunity and other chronic diseases is the overexpression of chemokines resulting in a detrimental local accumulation of proinflammatory immune cells. Chemokines play a pivotal role in cellular recruitment through interactions with both cell surface receptors and glycosaminoglycans (GAGs). Anti-inflammatory strategies aimed at neutralizing the chemokine system have to-date targeted inhibition of the receptor-ligand interaction with receptor antagonists. In this study, we describe a novel strategy to modulate the inflammatory process in vivo through mutation of the essential heparin-binding site of a proinflammatory chemokine, which abrogates the ability of the protein to form higher-order oligomers, but retains receptor activation. Using well-established protocols to induce inflammatory cell recruitment into the peritoneal cavity, bronchoalveolar air spaces, and CNS in mice, this non-GAG binding variant of RANTES/CCL5 designated [44AANA47]-RANTES demonstrated potent inhibitory capacity. Through a combination of techniques in vitro and in vivo, [44AANA47]-RANTES appears to act as a dominant-negative inhibitor for endogenous RANTES, thereby impairing cellular recruitment, not through a mechanism of desensitization. [44AANA47]-RANTES is unable to form higher-order oligomers (necessary for the biological activity of RANTES in vivo) and importantly forms nonfunctional heterodimers with the parent chemokine, RANTES. Therefore, although retaining receptor-binding capacity, altering the GAG-associated interactive site of a proinflammatory chemokine renders it a dominant-negative inhibitor, suggesting a powerful novel approach to generate disease-modifying anti-inflammatory reagents.

Inhibition of airway inflammation by amino-terminally modified RANTES/CC chemokine ligand 5 analogues is not mediated through CCR3

Chemokines play a key role in the recruitment of activated CD4(+) T cells and eosinophils into the lungs in animal models of airway inflammation. Inhibition of inflammation by N-terminally modified chemokines is well-documented in several models but is often reported with limited dose regimens. We have evaluated the effects of doses ranging from 10 ng to 100 micro g of two CC chemokine receptor antagonists, Met-RANTES/CC chemokine ligand 5 (CCL5) and aminooxypentane-RANTES/CCL5, in preventing inflammation in the OVA-sensitized murine model of human asthma. In the human system, aminooxypentane-RANTES/CCL5 is a full agonist of CCR5, but in the murine system neither variant is able to induce cellular recruitment. Both antagonists showed an inverse bell-shaped inhibition of cellular infiltration into the airways and mucus production in the lungs following allergen provocation. The loss of inhibition at higher doses did not appear to be due to partial agonist activity because neither variant showed activity in recruiting cells into the peritoneal cavity at these doses. Surprisingly, neither was able to bind to the major CCR expressed on eosinophils, CCR3. However, significant inhibition of eosinophil recruitment was observed. Both analogues retained high affinity binding for murine CCR1 and murine CCR5. Their ability to antagonize CCR1 and CCR5 but not CCR3 was confirmed by their ability to prevent RANTES/CCL5 and macrophage inflammatory protein-1beta/CCL4 recruitment in vitro and in vivo, while they had no effect on that induced by eotaxin/CCL11. These results suggest that CCR1 and/or CCR5 may be potential targets for asthma therapy.

CC chemokine ligand 5/RANTES chemokine antagonists aggravate glomerulonephritis despite reduction of glomerular leukocyte infiltration

The chemokine CC chemokine ligand (CCL)5/RANTES as well as its respective receptor CCR5 mediate leukocyte infiltration during inflammation and are up-regulated early during the course of glomerulonephritis (GN). We tested the effects of the two CCL5/RANTES blocking analogs, Met-RANTES and amino-oxypentane-RANTES, on the course of horse apoferritin (HAF)-induced GN. HAF-injected control mice had proliferative GN with mesangial immune complex deposits of IgG and HAF. Daily i.p. injections of Met-RANTES or amino-oxypentane-RANTES markedly reduced glomerular cell proliferation and glomerular macrophage infiltration, which is usually associated with less glomerular injury and proteinuria in HAF-GN. Surprisingly, however, HAF-GN mice treated with both analogs showed worse disease with mesangiolysis, capillary obstruction, and nephrotic range albuminuria. These findings were associated with an enhancing effect of the CCL5/RANTES analogs on the macrophage activation state, characterized by a distinct morphology and increased inducible NO synthetase expression in vitro and in vivo, but a reduced uptake of apoptotic cells in vivo. The humoral response and the Th1/Th2 balance in HAF-GN and mesangial cell proliferation in vitro were not affected by the CCL5/RANTES analogs. We conclude that, despite blocking local leukocyte recruitment, chemokine analogs can aggravate some specific disease models, most likely due to interactions with systemic immune reactions, including the removal of apoptotic cells and inducible NO synthetase expression.

Treatment with Met-RANTES reduces lung injury in caerulein-induced pancreatitis

BACKGROUND

Severe acute pancreatitis leads to a systemic inflammatory response characterized by widespread leucocyte activation and, as a consequence, distant lung injury. In CC chemokines the first two cysteine residues are adjacent to each other. The aim of this study was to evaluate the effect of Met-RANTES, a CC chemokine receptor antagonist, on pancreatic inflammation and lung injury in caerulein-induced acute pancreatitis in mice.

METHODS

Acute pancreatitis was induced in mice by hourly intraperitoneal injection of caerulein. Met-RANTES was administered either 30 min before or 1 h after starting caerulein injections, and pancreatic inflammation and lung injury were assessed. There were five groups of eight mice each including controls.

RESULTS

Treatment with Met-RANTES had little effect on caerulein-induced pancreatic damage. Met-RANTES, however, reduced lung injury when given either before administration of caerulein (mean(s.e.m.) lung myeloperoxidase (MPO) 1.47(0.19) versus 3.70(0.86)-fold increase over control, P = 0.024; mean(s.e.m.) microvascular permeability 1.15(0.05) versus 3.57(0.63) lavage to plasma fluorescein isothiocyanate-labelled albumin fluorescence ratio (L/P) per cent, P = 0.002) or after caerulein administration (lung MPO 1.96(0.27) versus 3.65(0.63)-fold increase over control, P = 0.029; microvascular permeability 0.94(0.04) versus 2.85(0.34) L/P per cent, P < 0.001).

CONCLUSION

Treatment with Met-RANTES reduces lung damage associated with caerulein-induced pancreatitis in mice. Chemokine receptor antagonists may be of use for the treatment of the systemic complications of acute pancreatitis.

Enhancement of mucosal immunization with virus-like particles of simian immunodeficiency virus

Cholera toxin (CT) is the most potent known mucosal adjuvant, but its toxicity precludes its use in humans. Here, in an attempt to develop safe and effective mucosal adjuvants, we compared immune responses to simian immunodeficiency virus (SIV) virus-like particles (VLPs) after intranasal coimmunization with RANTES, CpG oligodeoxynucleotides (ODN), or CT. Antibody analysis demonstrated that RANTES and CpG ODN had capacities for mucosal adjuvanticity, i.e., for enhancing serum and vaginal antibodies specific to SIV Env, similar to those for CT. RANTES and CpG ODN skewed serum antibodies predominantly to the immunoglobulin G2a isotype. Most importantly, RANTES and CpG ODN were more effective than CT in increasing neutralizing titers of both serum and vaginal antibodies. After intranasal coadministration with VLPs, RANTES or CpG ODN also induced increased levels of gamma interferon (IFN-gamma)-producing lymphocyte and cytotoxic T-lymphocyte activities in both spleen and lymph nodes but did not increase the levels of interleukin-4-producing lymphocytes. The results suggest that RANTES and CpG ODN enhance immune responses in a T-helper-cell-type-1 (Th1)-oriented manner and that they can be used as effective mucosal adjuvants for enhancing both humoral and cellular immune responses in the context of VLPs, which are particulate antigens.

Dipeptidyl peptidase IV expression in endometrial endometrioid adenocarcinoma and its inverse correlation with tumor grade

OBJECTIVES

Dipeptidyl peptidase IV (DPPIV)/CD26 is a cell surface aminopeptidase. This study investigated the expression and localization of DPPIV in endometrial endometrioid adenocarcinomas of different grades.

STUDY DESIGN

Immunohistochemical analysis was performed by using DPPIV and regulated on activation, normal T-cell expressed and secreted (RANTES) specific monoclonal antibodies. Cell proliferation was evaluated by bromodeoxyuridine (BrdU) uptake assay.

RESULTS

Immunohistochemical analyses showed that DPPIV was strongly or moderately stained in glandular cells of the normal secretory phase. In endometrial adenocarcinoma, the DPPIV expression decreased with advancing grade (P <.01). Furthermore, RANTES, one of the possible DPPIV substrates, was highly expressed in all grades of endometrial adenocarcinoma cells. The addition of RANTES to endometrial adenocarcinoma cells increased proliferation in a concentration-dependent manner.

CONCLUSION

DPPIV is expressed in normal endometrial glandular cells, but its expression in endometrial adenocarcinoma is down-regulated with increasing grade. Our data also suggest a regulatory role of this ectoenzyme in neoplastic transformation and progression of endometrial adenocarcinomas possibly by degrading certain bioactive peptides such as RANTES.

A hydrogel prepared by in situ cross-linking of a thiol-containing poly(ethylene glycol)-based copolymer: a new biomaterial for protein drug delivery

A new poly(ethylene glycol)-based copolymer containing multiple thiol (-SH) groups was cross-linked in situ to form a polymer hydrogel under mild conditions. No organic solvent, elevated temperature, or harsh pH is required in the formulation or patient administration processes, making it particularly useful for delivery of fragile therapeutics, such as proteins. The in vitro release of fluorescein-labeled bovine serum albumin and the in vivo release of the model proteins, erythropoietin, RANTES and three PEG-conjugated RANTES derivatives showed sustained release for 2-4 weeks and demonstrated prolonged biological activity of the released proteins in animals.

Differential sensitivities of pyrogenic chemokine fevers to cyclooxygenase isozymes antibodies

It has been proposed that prostaglandin (PG)E(2) production via a process catalyzed by the inducible isoform of cyclooxygenase (COX)-2 and activation of specific PGE(2) receptor subtypes within the preoptic/anterior hypothalamus (AH/POA) is the last step and unique pathway in the induction of a fever. However, many data support the existence of a PG-independent pathway. That is, other more rapid mechanisms, which involve the constitutive COX-1 isozyme, may be more critical for a PG-dependent fever. Thus, we examined the role of both COX isoforms in the AH/POA in fevers induced by macrophage inflammatory protein (MIP)-1beta, a PG-independent pyrogen, and RANTES (regulated on activation, normal T-cells expressed and secreted), a PG-dependent pyrogen. In freely moving rats, two independent polyclonal antibodies were used which neutralize COX-1 and COX-2. The microinjection of either MIP-1beta or RANTES into the pyrogen-sensitive region of the AH/POA induced an intense fever of rapid onset. Peripheral pretreatment with an antipyretic dose of dexamethasone which prevents COX-2 expression, or the microinjections into the AH/POA of either anti-COX-1 or anti-COX-2, blocked the febrile response induced by RANTES but not that induced by MIP-1beta. These results provide strong evidence for the existence of rapid mechanisms in the AH/POA which involve both COX isozymes during the fever induced by RANTES, and further support the existence of an alternative PG-independent pathway in the febrile response.

In vivo effects of a synthetic 2-kilodalton macrophage-activating lipopeptide of Mycoplasma fermentans after pulmonary application

Mycoplasmas can cause interstitial pneumonias inducing critical illness in humans and animals. Mycoplasma infections are characterized by an influx of neutrophils, followed by an accumulation of macrophages and lymphocytes. The present study deals with the question of which mycoplasmal components cause this host reaction. The mycoplasma-derived, macrophage-activating lipopeptide 2S-MALP-2 was used to mimic the sequelae of a mycoplasma infection. To this end, 2S-MALP-2 was intratracheally instilled into the lungs of Lewis rats, and the bronchoalveolar lavage cells were examined at different times after different doses of 2S-MALP-2. Application of 2.5 microg induced a pronounced leukocyte accumulation in the bronchoalveolar space. At 24 h after 2S-MALP-2 administration, the majority of leukocytes consisted of neutrophils, followed by macrophages, peaking on days 2 and 3. Lymphocyte numbers, although amounting to only a few percent of the total bronchoalveolar lavage cells, also increased significantly, with maximal lymphocyte accumulation occurring by 72 h after instillation. The leukocyte count of the lung interstitium was increased on day 3 after treatment. After 10 days all investigated cell populations returned to control levels. Transient chemotactic activity for neutrophils was detected in the bronchoalveolar lavage fluid early after 2S-MALP-2 application, followed by monocyte chemoattractant protein-1 activity (MCP-1) in lung homogenates. MCP-1 was produced by bronchoalveolar lavage cells upon stimulation with 2S-MALP-2. Our data indicate that mycoplasmal lipoproteins and lipopeptides are probably the most relevant mycoplasmal components for the early host reaction. The primary target cells are likely to be the alveolar macrophages liberating chemokines, which attract further leukocytes.

Stem cell factor-induced leukotriene B4 production cooperates with eotaxin to mediate the recruitment of eosinophils during allergic pleurisy in mice

The understanding of the mechanisms underlying eosinophil recruitment in vivo may aid in the development of novel strategies for the treatment of allergic disorders. In this study, we investigated the role of chemokines in the cascade of events leading to eosinophil recruitment in a stem cell factor (SCF)- and leukotriene B(4) (LTB(4))-dependent allergic pleurisy model in mice. The intrapleural administration of the eosinophil-active chemokines eotaxin, RANTES, and macrophage-inflammatory protein 1alpha (MIP-1alpha) induced a time- and dose-dependent eosinophil recruitment. Pretreatment with anti-eotaxin, but not anti-RANTES or anti-MIP-1alpha, blocked the recruitment of eosinophils following Ag challenge of sensitized animals, and significant eotaxin immunoreactivity was detected in the pleural cavity of these animals. Similarly, only the anti-eotaxin inhibited the eosinophil recruitment induced by injection of SCF in naive animals. However, blockade of SCF did not inhibit the release of eotaxin after Ag challenge of sensitized mice. Akin to its effects on SCF and in the allergic reaction, eotaxin-induced eosinophil recruitment was blocked by the LTB(4) receptor antagonist CP105696. Nevertheless, SCF, but not eotaxin, appeared to regulate the endogenous release of LTB(4) after Ag challenge. Finally, we show that low doses of eotaxin synergized with LTB(4) to induce eosinophil recruitment in the pleural cavity. Overall, the present results show that eotaxin and SCF-induced LTB(4) cooperate to induce eosinophil recruitment into sites of allergic inflammation. Cooperation between inflammatory mediators must be an important phenomenon in vivo, explaining both the ability of lower concentrations of mediators to induce a full-blown functional response and the effectiveness of different strategies at inhibiting these responses.

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.

The chemokine RANTES is a crucial mediator of the progression from acute to chronic colitis in the rat

Chemokines have well characterized proinflammatory actions, including the ability to induce extravasation of leukocytes that participate in chronic inflammation. In this study, we evaluated the role of a C-C chemokine, RANTES, in the chronic phase of a rat model of colitis. Colitis was induced by intracolonic administration of trinitrobenzene sulfonic acid. At various timepoints thereafter (2 h to 14 days), colonic tissue levels of several chemokines were measured. Unlike the expression of monocyte chemoattractant protein-1, macrophage inflammatory protein-2, and cytokine-induced neutrophil chemoattractant, the expression of RANTES was significantly elevated during the chronic phase of colitis (> or =7 days after induction). Colonic RANTES mRNA expression was also significantly elevated during the chronic phase of colitis. The numbers of macrophages and monocytes in the colonic mucosa increased substantially during the chronic phase, as did expression of two of the receptors (CCR1 and CCR5) to which RANTES is known to bind. Administration on days 7 through 14 after trinitrobenzene sulfonic acid administration of a CCR1/CCR5 receptor antagonist, Met-RANTES, resulted in a significant reduction of both macroscopic and microscopic colonic damage, as well as reducing the recruitment into the colon of monocytes, mast cells, and neutrophils. In some rats, treatment with Met-RANTES resulted in a near-complete resolution of colonic damage and inflammation. These results suggest a crucial role of RANTES in the progression from acute to chronic inflammation in a rat model of colitis.

RANTES: a new prostaglandin dependent endogenous pyrogen in the rat

Fever, a hallmark of disease, is a highly complex process initiated by the action of a number of endogenous pyrogens on the thermosensitive cells of the brain. We describe the activity of RANTES, a chemotactic cytokine, as intrinsically pyrogenic in the rat, when it is delivered directly to the thermosensitive region of the rat's anterior hypothalamic, pre-optic area (AH/POA). RANTES, microinjected into the AH/POA in a dose of 1, 5, 10, 15, 25 or 50 pg, produces an immediate and intense dose-related fever following injection. Increasing the dose to 100 pg did not result in a further increase in the febrile response. No significant change in body temperature was produced by heat-inactivated RANTES. The intrahypothalamic injection of antibodies against RANTES (2.0 microg, 15 min prior to RANTES) significantly blocked the fever induced by this chemokine. Pretreatment with ibuprofen blocked the fever induced by RANTES. In order of potency, the magnitude of the febrile response induced by RANTES was greater than that produced with equipotent doses of either macrophage inflammatory protein-1beta or interleukin-6. The results thus demonstrate that RANTES is the most potent endopyrogen discovered thus far and exerts its action directly on pyrogen-sensitive cells of the AH/POA through a prostaglandin-dependent pathway.

Role of CC chemokines (macrophage inflammatory protein-1 beta, monocyte chemoattractant protein-1, RANTES) in acute lung injury in rats

The role of the CC chemokines, macrophage inflammatory protein-1 beta (MIP-1 beta), monocyte chemotactic peptide-1 (MCP-1), and RANTES, in acute lung inflammatory injury induced by intrapulmonary deposition of IgG immune complexes injury in rats was determined. Rat MIP-1 beta, MCP-1, and RANTES were cloned, the proteins were expressed, and neutralizing Abs were developed. mRNA and protein expression for MIP-1 beta and MCP-1 were up-regulated during the inflammatory response, while mRNA and protein expression for RANTES were constitutive and unchanged during the inflammatory response. Treatment of rats with anti-MIP-1 beta Ab significantly decreased vascular permeability by 37% (p = 0.012), reduced neutrophil recruitment into lung by 65% (p = 0.047), and suppressed levels of TNF-alpha in bronchoalveolar lavage fluids by 61% (p = 0.008). Treatment of rats with anti-rat MCP-1 or anti-rat RANTES had no effect on the development of lung injury. In animals pretreated intratracheally with blocking Abs to MCP-1, RANTES, or MIP-1 beta, significant reductions in the bronchoalveolar lavage content of these chemokines occurred, suggesting that these Abs had reached their targets. Conversely, exogenously MIP-1 beta, but not RANTES or MCP-1, caused enhancement of the lung vascular leak. These data indicate that MIP-1 beta, but not MCP-1 or RANTES, plays an important role in intrapulmonary recruitment of neutrophils and development of lung injury in the model employed. The findings suggest that in chemokine-dependent inflammatory responses in lung CC chemokines do not necessarily demonstrate redundant function.

Contrasting roles for RANTES and macrophage inflammatory protein-1 alpha (MIP-1 alpha) in a murine model of allergic peritonitis

Cell accumulation and CC chemokine production were assessed in the peritoneal cavity of ovalbumin (OVA)-sensitized mice following antigen challenge. Intraperitoneal challenge with OVA induced a significant eosinophil influx from 6 h post-challenge with increased numbers persisting at 24 h. At 6 h there was also a marked presence of neutrophils. Messenger RNA expression and protein levels for the chemokines RANTES and MIP-1 alpha were measured in the cell pellets and supernatants, respectively, from peritoneal washes following OVA challenge. RANTES mRNA was detected from 2 h to 4 h following OVA injection, whereas mRNA for MIP-1 alpha was only detectable at 4 h. RANTES protein was first detected from 4 h after OVA injection and by 24 h the protein levels had increased further. Basal levels of MIP-1 alpha were detected in peritoneal washes. These levels peaked at 2 h after OVA challenge and rapidly declined to basal levels by 6 h. A functional role for the chemokines was assessed using neutralizing polyclonal antibodies. Co-injection of OVA with anti-RANTES antibodies resulted in a significant inhibition of eosinophil infiltration into the cavity at 6 h and 24 h (63% and 52% inhibition, respectively) without significantly influencing the number of neutrophils present. In contrast, injection of anti-MIP-1 alpha antibodies only inhibited neutrophil migration at the 6 h time point by 44% without significantly affecting the accumulation of eosinophils. These results demonstrate an important role for RANTES in mediating eosinophil influx in allergic inflammation and a contrasting role for MIP-1 alpha in mediating neutrophil recruitment.

Differential expression and cross-regulatory function of RANTES during mycobacterial (type 1) and schistosomal (type 2) antigen-elicited granulomatous inflammation

The role of RANTES in Th1 and Th2 cell-mediated immune responses has been enigmatic. To approach this question, we analyzed RANTES expression and function in murine models of types 1 and 2 cell-mediated pulmonary granulomas elicited with Mycobacterium bovis or Schistosoma mansoni egg Ag-coated beads, respectively. Compared with type 2, type 1 lesions had up to 4-fold greater RANTES protein and mRNA production. Type 1 draining lymph nodes also produced up to 7-fold higher levels of RANTES. Anti-RANTES Ab treatments had opposite effects, decreasing type 1 lesion area by 25% and augmenting type 2 lesions by 50%. The latter was associated with increased IL-4, IL-5, IL-10, and IL-13 production by lymph nodes. Infusion of rRANTES (1 mg/kg/day) did not affect type 1 lesions, but reduced type 2 lesion area by 27% and eosinophils by 40%. Lymph node cultures from RANTES-treated mice had augmented type 1 and impaired type 2 responses. In vitro, RANTES caused selective, dose-related inhibition of IL-4 that was largely dependent on CCR1 receptors. In conclusion, RANTES plays different roles in types 1 and 2 granuloma formation, promoting the former and mediating cross-regulatory inhibition of the latter. Moreover, RANTES may have therapeutic potential in the treatment of established type 2 hypersensitivity.

Mast cell recruitment after subcutaneous injection of RANTES in the sole of the rat paw

The effect of hrRANTES was studied after the injection in the sole of the rat paw, an area particularly rich in mast cells. Subcutaneous injections of RANTES 50 ng/10 microl produced an erythematous reaction which was inhibited by anti-RANTES antibody 50 microg/rat injected in the tail vein 30 min before hrRANTES 50 ng/10 microl was injected. In another set of experiments the animals were injected subcutaneously in the sole of the paw with PBS 10 microl (control), LPS (100 ng/10 microl) hrRANTES 50 ng/10 microl or anti-RANTES 50 microl/rat injected in the tail vein 30 min before hrRANTES 50 ng/10 microl was injected. The biopsies were analysed after 4 h and counted in an optic field. hrRANTES produced a strong recruitment of mast cells selectively coloured with 0.1% toluidine blue and inhibited by anti-RANTES antibody. In addition to the optical and electron microscope study, in some of the excised tissue Northern blot analysis for histidine decarboxylase (HDC) mRNA was performed to estimate the amount of histamine generation in the tissue of the injection sites. We found that subcutaneous injections of hrRANTES 50 ng/10 microl in the sole of the rat paw produced an accumulation of a great number of mast cells compared to PBS 10 microl (negative control) or LPS 100 ng/10 microl (positive control) after 4 h. The hrRANTES effect was inhibited by anti-RANTES antibody injected in the tail vein 30 min before hrRANTES exposure. Moreover, hrRANTES increased HDC mRNA and histamine generation.

Cutaneous injection of RANTES causes eosinophil recruitment: comparison of nonallergic and allergic human subjects

RANTES, a member of the C-C chemokine family, is a potent chemoattractant for T lymphocytes and eosinophils, but not neutrophils. To determine the effect of RANTES on cell recruitment in vivo, we injected up to 4 microg of RANTES intradermally into both allergic and nonallergic subjects and obtained biopsies 30 min, 6 h, and 24 h later. A dose- and time-dependent recruitment of eosinophils, CD45RO+ cells, and CD3+ cells was observed, with no effect seen on polymononuclear, cutaneous lymphocyte Ag+, CD68+, or tryptase+ cells. Eosinophil recruitment occurred more rapidly in allergic subjects than in nonallergic subjects. No eosinophil infiltrate was observed in nonallergic biopsies at 30 min and 6 h, whereas significant eosinophil recruitment was observed in allergic subjects by 30 min, reaching near-maximum levels by 6 h. The peak responses at 24 h were similar in both groups (nonallergic, 110 +/- 24 eosinophils/mm2; allergic, 113 +/- 38 eosinophils/mm2). The two groups had comparable numbers of circulating eosinophils. Major basic protein staining demonstrated eosinophil degranulation in both allergic and nonallergic groups. RANTES injection resulted in activation of endothelial E-selectin expression at 24 h. Incubation of cultured HUVECs with RANTES had no effect on adhesion molecule expression, suggesting that the in vivo effect may have been indirect. Our studies demonstrate that RANTES is a potent chemoattractant for eosinophils, CD3+ cells, and CD45RO+ cells in human skin. The accelerated eosinophil recruitment in allergic subjects provides support for the hypothesis that eosinophils from these subjects are primed in vivo.

Impact of Rantes and MCP-1 chemokines on in vivo basophilic cell recruitment in rat skin injection model and their role in modifying the protein and mRNA levels for histidine decarboxylase

RANTES and related molecules, constitute the C-C class of chemokine supergene family and a group of cytokines produced by hematopoietic cells constitute the MCP-1 or C-X-C class. The roles of most of these chemokines are not well known, although members of the C-X-C family are inflammatory agents. Here, we report that intradermal injection of RANTES 10 ng/50 microL subcutaneously in the abdominal skin produced a strong inflammatory reaction, as evidenced by Evans blue dye, greater than FMLP (10(-6) mol/L) (approximately 57%); while MCP-1, 10 ng/50 microL was less effective than FMLP (10(-6) mol/L) (approximately 54%). Moreover, the histologic analysis of the cells stained with Toluidine blue (0.1%) were analyzed at a magnification of x40). RANTES 10 ng/50 microL and LPS produced higher numbers (142 +/- 11 and 193 +/- 21 of cells/200 mm2, respectively) of basophilic cell accumulation in the skin injection sites compared with FMLP (10(-6) mol/L) (127 +/- 14/200 mm2), while MCP-1 10 ng/50 microL was less effective (88 +/- 10/200 mm2). Electron microscopy (x13,800) studies of skin injection sites revealed that RANTES was chemoattractant for mast cells. In a Northern blot analysis from homogeneous tissue biopsy from the intradermal injection sites, RANTES was more potent than MCP-1 in increasing histidine decarboxylase (HDC) mRNA, the sole enzyme responsible for the production of histamine from histidine. Since PGD2 is formed by mast cells on cell activation, we also studied the effect of RANTES and MCP-1 on PGD2 production in inflamed tissue in vivo. RANTES (20, 10, and 5 ng) and MCP-1 (20, 10, and 5 ng) strongly stimulated PGD2, in a dose-dependent manner, with a potency rank order of RANTES (10 ng/mL) approximately two times greater than MCP-1 (10 ng/mL).

Chemokines and T lymphocyte activation: II. Facilitation of human T cell trafficking in severe combined immunodeficiency mice

Previous studies from this laboratory have demonstrated that the chemokines RANTES (recombinant human regulated upon activation, normally T cell expressed and presumably secreted), macrophage chemotactic peptide-1, recombinant human macrophage inflammatory protein-1 alpha (rhMIP-1 alpha) IL-8, and IP-10 are capable of inducing human T cell infiltration into the injection site of severe combined immunodeficiency (SCID) mice reconstituted with human PBL. However, the ability of these chemokines to facilitate T cell homing into various lymphoid tissues has not been examined. Initial studies focused on the ability of rhMIP-1 beta to induce human T cell infiltration into injection sites in human PBL-SCID mice. SCID mice received s.c. injections of rhMIP-1 beta or PBS (1 microgram/injection) in the hindflank for 4 h or sequential injections for 3 days. Biopsies of the MIP-1 beta injection site revealed the presence of significant mononuclear cell accumulation 72 h after injection. Immunohistologic evaluation determined that significant numbers of human CD3+ T cells were recruited in response to MIP-1 beta injections, and this infiltration could be specifically blocked by co-administration of anti-MIP-1 beta antiserum. We subsequently examined these chemokine-injected mice for the effect of trafficking of human T cells to peripheral lymphoid organs. Flow cytometric analysis of the thymus in human PBL-SCID mice revealed that treatment with rhMIP-1 beta or rhRANTES, but not platelet factor-4, resulted in improved thymic homing of the human T cells after 72 h. This trafficking effect was shown to be direct, as pretreatment of the human T cells with the chemokines in vitro also improved peripheral lymphoid trafficking of the human cells. In addition, co-injection of rhMIP-1 beta with anti-1 beta antiserum abrogated the increase in T cell homing to the thymus. These data demonstrate that MIP-1 beta and RANTES directly augment human T cell trafficking to peripheral murine lymphoid tissues. Chemokines may, therefore, under either isogeneic or xenogeneic conditions, play a role in normal lymphocyte recirculation and homing, and may be of potential clinical use in promoting immune cell trafficking and function.