Regulatory effects of eotaxin on acute lung inflammatory injury

Eotaxin, which is a major mediator for eosinophil recruitment into lung, has regulatory effects on neutrophil-dependent acute inflammatory injury triggered by intrapulmonary deposition of IgG immune complexes in rats. In this model, eotaxin mRNA and protein were up-regulated during the inflammatory response, resulting in eotaxin protein expression in alveolar macrophages and in alveolar epithelial cells. Ab-induced blockade of eotaxin in vivo caused enhanced NF-kappaB activation in lung, substantial increases in bronchoalveolar lavage levels of macrophage inflammatory protein (MIP)-2 and cytokine-induced neutrophil chemoattractant (CINC), and increased MIP-2 and CINC mRNA expression in alveolar macrophages. In contrast, TNF-alpha levels were unaffected, and IL-10 levels fell. Under these experimental conditions, lung neutrophil accumulation was significantly increased, and vascular injury, as reflected by extravascular leak of (125)I-albumin, was enhanced. Conversely, when recombinant eotaxin was administered in the same inflammatory model of lung injury, bronchoalveolar lavage levels of MIP-2 were reduced, as was neutrophil accumulation and the intensity of lung injury. In vitro stimulation of rat alveolar macrophages with IgG immune complexes greatly increased expression of mRNA and protein for MIP-2, CINC, MIP-1alpha, MIP-1beta, TNF-alpha, and IL-1beta. In the copresence of eotaxin, the increased levels of MIP-2 and CINC mRNAs were markedly diminished, whereas MIP-1alpha, MIP-1beta, TNF-alpha, and IL-1beta expression of mRNA and protein was not affected. These data suggest that endogenous eotaxin, which is expressed during the acute lung inflammatory response, plays a regulatory role in neutrophil recruitment into lung and the ensuing inflammatory damage.     

Monocyte chemotactic protein-1 regulates leukocyte recruitment during gastric ulcer recurrence induced by tumor necrosis factor-alpha

TNF-alpha has numerous biological activities, including the induction of chemokine expression, and is involved in many gastric injuries. C-C chemokines [monocyte chemotactic protein (MCP)-1 and macrophage inflammatory protein (MIP)-1alpha] and C-X-C chemokines [MIP-2 and cytokine-induced neutrophil chemoattractant (CINC)-2alpha] mediate chemotaxis of monocytes and neutrophils, respectively. We examined the roles of TNF-alpha and dynamics of chemokine expression in gastric ulceration including ulcer recurrence and indomethacin-induced injury. Rats with healed chronic gastric ulcers received intraperitoneal TNF-alpha to induce ulcer recurrence. Some rats were given neutralizing antibodies against neutrophils or MCP-1 together with TNF-alpha. In a separate experiment, rats were orally administered 20 mg/kg indomethacin with or without pretreatment with pentoxifylline (an inhibitor of TNF-alpha synthesis) or anti-MCP-1 antibody. TNF-alpha (1 microg/kg) induced gastric ulcer recurrence after 48 h, which was completely prevented by anti-neutrophil antibody. TNF-alpha increased the number of macrophages and MCP-1 mRNA expression in scarred mucosa from 4 h, whereas it increased MPO activities (marker of neutrophil infiltration) and mRNA expression of MIP-2 and CINC-2alpha from 24 h. Anti-MCP-1 antibody inhibited leukocyte infiltration with reduction of the levels of C-X-C chemokines and prevented ulcer recurrence. Indomethacin treatment increased TNF-alpha/chemokine mRNA expression from 30 min and induced macroscopic erosions after 4 h. Pentoxifylline inhibited the indomethacin-induced gastric injury with reduction of neutrophil infiltration and expression of chemokine (MCP-1, MIP-2, and CINC-2alpha). Anti-MCP-1 antibody also inhibited the injury and these inflammatory responses but did not affect TNF-alpha mRNA expression. In conclusion, increased MCP-1 triggered by TNF-alpha may play a key role in gastric ulceration by regulating leukocyte recruitment and chemokine expression.     

Enhancing effect of IL-1, IL-17, and TNF-alpha on macrophage inflammatory protein-3alpha production in rheumatoid arthritis: regulation by soluble receptors and Th2 cytokines.

Macrophage inflammatory protein (MIP)-3alpha is a chemokine involved in the migration of T cells and immature dendritic cells. To study the contribution of proinflammatory cytokines and chemokines to the recruitment of these cells in rheumatoid arthritis (RA) synovium, we looked at the effects of the monocyte-derived cytokines IL-1beta and TNF-alpha and the T cell-derived cytokine IL-17 on MIP-3alpha production by RA synoviocytes. Addition of IL-1beta, IL-17, and TNF-alpha induced MIP-3alpha production in a dose-dependent manner. At optimal concentrations, IL-1beta (100 pg/ml) was much more potent than IL-17 (100 ng/ml) and TNF-alpha (100 ng/ml). When combined at lower concentrations, a synergistic effect was observed. Conversely, the anti-inflammatory cytokines IL-4 and IL-13 inhibited MIP-3alpha production by activated synoviocytes, but IL-10 had no effect. Synovium explants produced higher levels of MIP-3alpha in RA than osteoarthritis synovium. MIP-3alpha-producing cells were located in the lining layer and perivascular infiltrates in close association with CD1a immature dendritic cells. Addition of exogenous IL-17 or IL-1beta to synovium explants increased MIP-3alpha production. Conversely, specific soluble receptors for IL-1beta, IL-17, and TNF-alpha inhibited MIP-3alpha production to various degrees, but 95% inhibition was obtained only when the three receptors were combined. Similar optimal inhibition was also obtained with IL-4, but IL-13 and IL-10 were less active. These findings indicate that interactions between monocyte and Th1 cell-derived cytokines contribute to the recruitment of T cells and dendritic cells by enhancing the production of MIP-3alpha by synoviocytes. The inhibitory effect observed with cytokine-specific inhibitors and Th2 cytokines may have therapeutic applications.     

TNF-alpha is a potent inducer for IFN-inducible protein-10 in hepatocytes and unaffected by GM-CSF in vivo, in contrast to IL-1beta and IFN-gamma

We have recently shown that IFN-inducible protein 10 (IP-10), a member of the CXC chemokine family, is induced in hepatocytes surrounded by infiltrative mononuclear cells in human livers with chronic hepatitis. Hence, we examined the kinds of stimuli that can induce IP-10 expression in hepatocytes in vivo. While the liver expressed three chemokine genes (IP-10, JE/MCP-1, KC/GRO) in a tissue-specific fashion following systemic treatment with pro-inflammatory cytokines, IP-10 mRNA expression showed the most marked liver-specificity. Pretreatment with GM-CSF selectively inhibited IL-1beta, but not TNF-alpha-induced IP-10 mRNA expression. In situ hybridization analysis in the liver and Northern hybridization analysis in isolated liver cell fractions from rodents treated with pro-inflammatory cytokines revealed cellular sources of chemokine expression. IP-10 mRNA expression in hepatocytes was induced by i.v. administration of TNF-alpha, and to a much lesser extent in response to IL-1beta and IFN-gamma, whereas Kupffer cells and endothelial cells expressed IP-10 mRNA equivalently in response to these three stimuli. On the other hand, JE/MCP-1 mRNA expression was detected only in non-parenchymal cells in response to TNF-alpha and IL-1beta, but not in response to IFN-gamma. KC/GRO mRNA expression was also induced mainly in sinusoidal cells by treatment with TNF-alpha or IL-1beta, although it was detected to a lesser extent in hepatocytes. Our results demonstrated that chemokine induction is stimulus-, tissue- and cell type-specific and that IP-10 (but not MCP-1) is inducible in hepatocytes by TNF-alpha most potently, even in the presence of GM-CSF, suggesting the specific role of TNF-alpha-induced IP-10 on intralobular mononuclear infiltration in chronic hepatitis.     

Estrogen modulates TNF-alpha-induced inflammatory responses in rat aortic smooth muscle cells through estrogen receptor-beta activation

We have previously shown that 17beta-estradiol (E2) attenuates responses to endoluminal injury of the rat carotid artery, at least in part, by decreasing inflammatory mediator expression and neutrophil infiltration into the injured vessel, with a major effect on the neutrophil-specific chemokine cytokine-induced neutrophil chemoattractant (CINC)-2 beta. Current studies tested the hypothesis that activated rat aortic smooth muscle cells (RASMCs) express these same inflammatory mediators and induce neutrophil migration in vitro and that E2 inhibits these processes by an estrogen receptor (ER)-dependent mechanism. Quiescent RASMCs treated with E2, the ER alpha-selective agonist propyl pyrazole triol (PPT), the ER beta-selective agonist diarylpropiolnitrile (DPN), or vehicle for 24 h were stimulated with tumor necrosis factor (TNF)-alpha and processed for real-time RT-PCR, ELISA, or chemotaxis assays 6 h later. TNF-alpha stimulated and E2 attenuated mRNA expression of inflammatory mediators, including P-selectin, intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, monocyte chemoattractant protein (MCP)-1, and CINC-2 beta. DPN dose dependently attenuated TNF-alpha-induced mRNA expression of CINC-2 beta, whereas PPT had no effect. The anti-inflammatory effects of DPN and E2 were blocked by the nonselective ER-inhibitor ICI-182,780. ELISA confirmed the TNF-alpha-induced increase and E2-induced inhibition of CINC-2 beta protein secretion. TNF-alpha treatment of RASMCs produced a twofold increase in neutrophil chemotactic activity of conditioned media; E2 and DPN treatment markedly inhibited this effect. E2 inhibits activated RASMC proinflammatory mediator expression and neutrophil chemotactic activity through an ER beta-dependent mechanism.     

Critical role for CXCR3 chemokine biology in the pathogenesis of bronchiolitis obliterans syndrome

Bronchiolitis obliterans syndrome (BOS) is the major limitation to survival post-lung transplantation and is characterized by a persistent peribronchiolar inflammation that eventually gives way to airway fibrosis/obliteration. Acute rejection is the main risk factor for the development of BOS and is characterized by a perivascular/bronchiolar leukocyte infiltration. The specific mechanism(s) by which these leukocytes are recruited have not been elucidated. The CXC chemokines (monokine induced by IFN-gamma (MIG)/CXC chemokine ligand (CXCL)9, IP-10/CXCL10, and IFN-inducible T cell alpha chemoattractant (ITAC)/CXCL11) act through their shared receptor, CXCR3. Because they are potent leukocyte chemoattractants and are involved in other inflammation/fibroproliferative diseases, we hypothesized that the expression of these chemokines during an allogeneic response promotes the persistent recruitment of mononuclear cells, leading to chronic lung rejection. We found that elevated levels of MIG/CXCL9, IFN-inducible protein 10 (IP-10)/CXCL10, and ITAC/CXCL11 in human bronchoalveolar lavage fluid were associated with the continuum from acute to chronic rejection. Translational studies in a murine model demonstrated increased expression of MIG/CXCL9, IP-10/CXCL10, and ITAC/CXCL11 paralleling the recruitment of CXCR3-expressing mononuclear cells. In vivo neutralization of CXCR3 or its ligands MIG/CXCL9 and IP-10/CXCL10 decreased intragraft recruitment of CXCR3-expressing mononuclear cells and attenuated BOS. This supports the notion that ligand/CXCR3 biology plays an important role in the recruitment of mononuclear cells, a pivotal event in the pathogenesis of BOS.     

The murine chemokine CXCL11 (IFN-inducible T cell alpha chemoattractant) is an IFN-gamma- and lipopolysaccharide-inducible glucocorticoid-attenuated response gene expressed in lung and other tissues during endotoxemia

A new murine chemokine was identified in a search for glucocorticoid-attenuated response genes induced in the lung during endotoxemia. The first 73 residues of the predicted mature peptide are 71% identical and 93% similar to human CXCL11/IFN-inducible T cell alpha chemoattractant (I-TAC) (alias beta-R1, H174, IFN-inducible protein 9 (IP-9), and SCYB9B). The murine chemokine has six additional residues at the carboxyl terminus not present in human I-TAC. Identification of this cDNA as murine CXCL11/I-TAC is supported by phylogenetic analysis and by radiation hybrid mapping of murine I-TAC (gene symbol Scyb11) to mouse chromosome 5 close to the genes for monokine induced by IFN-gamma (MIG) and IP10. Murine I-TAC mRNA is induced in RAW 264.7 macrophages by IFN-gamma or LPS and is weakly induced by IFN-alphabeta. IFN-gamma induction of murine I-TAC is markedly enhanced by costimulation with LPS or IL-1beta in RAW cells and by TNF-alpha in both RAW cells and Swiss 3T3 fibroblasts. Murine I-TAC is induced in multiple tissues during endoxemia, with strongest expression in lung, heart, small intestine, and kidney, a pattern of tissue expression different from those of MIG and IP10. Peak expression of I-TAC message is delayed compared with IP10, both in lung after i.v. LPS and in RAW 264.7 cells treated with LPS or with IFN-gamma. Pretreatment with dexamethasone strongly attenuates both IFN-gamma-induced I-TAC expression in RAW cells and endotoxemia-induced I-TAC expression in lung and small intestine. The structural and regulatory similarities of murine and human I-TAC suggest that mouse models will be useful for investigating the role of this chemokine in human biology and disease.     

Hemozoin-inducible proinflammatory events in vivo: potential role in malaria infection

During malaria infection, high levels of proinflammatory molecules (e.g., cytokines, chemokines) correlate with disease severity. Even if their role as activators of the host immune response has been studied, the direct contribution of hemozoin (HZ), a parasite metabolite, to such a strong induction is not fully understood. Previous in vitro studies demonstrated that both Plasmodium falciparum HZ and synthetic HZ (sHZ), beta-hematin, induce macrophage/monocyte chemokine and proinflammatory cytokine secretion. In the present study, we investigated the proinflammatory properties of sHZ in vivo. To this end, increasing doses of sHZ were injected either i.v. or into an air pouch generated on the dorsum of BALB/c mice over a 24-h period. Our results showed that sHZ is a strong modulator of leukocyte recruitment and more specifically of neutrophil and monocyte populations. In addition, evaluation of chemokine and cytokine mRNA and protein expression revealed that sHZ induces the expression of chemokines, macrophage-inflammatory protein (MIP)-1alpha/CCL3, MIP-1beta/CCL4, MIP-2/CXCL2, and monocyte chemoattractant protein-1/CCL2; chemokine receptors, CCR1, CCR2, CCR5, CXCR2, and CXCR4; cytokines, IL-1beta and IL-6; and myeloid-related proteins, S100A8, S100A9, and S100A8/A9, in the air pouch exudates. Of interest, chemokine and cytokine mRNA up-regulation were also detected in the liver of i.v. sHZ-injected mice. In conclusion, our study demonstrates that sHZ is a potent proinflammatory agent in vivo, which could contribute to the immunopathology related to malaria.     

Regulation of macrophage chemokine expression by lipopolysaccharide in vitro and in vivo.

The host response to Gram-negative LPS is characterized by an influx of inflammatory cells into host tissues, which is mediated, in part, by localized production of chemokines. The expression and function of chemokines in vivo appears to be highly selective, though the molecular mechanisms responsible are not well understood. All CXC (IFN-gamma-inducible protein (IP-10), macrophage inflammatory protein (MIP)-2, and KC) and CC (JE/monocyte chemoattractant protein (MCP)-1, MCP-5, MIP-1alpha, MIP-1beta, and RANTES) chemokine genes evaluated were sensitive to stimulation by LPS in vitro and in vivo. While IL-10 suppressed the expression of all LPS-induced chemokine genes evaluated in vitro, treatment with IFN-gamma selectively induced IP-10 and MCP-5 mRNAs, but inhibited LPS-induced MIP-2, KC, JE/MCP-1, MIP-1alpha, and MIP-1beta mRNA and/or protein. Like the response to IFN-gamma, LPS-mediated induction of IP-10 and MCP-5 was Stat1 dependent. Interestingly, only the IFN-gamma-mediated suppression of LPS-induced KC gene expression was IFN regulatory factor-2 dependent. Treatment of mice with LPS in vivo also induced high levels of chemokine mRNA in the liver and lung, with a concomitant increase in circulating protein. Hepatic expression of MIP-1alpha, MIP-1beta, RANTES, and MCP-5 mRNAs were dramatically reduced in Kupffer cell-depleted mice, while IP-10, KC, MIP-2, and MCP-1 were unaffected or enhanced. These findings indicate that selective regulation of chemokine expression in vivo may result from differential response of macrophages to pro- and antiinflammatory stimuli and to cell type-specific patterns of stimulus sensitivity. Moreover, the data suggest that individual chemokine genes are differentially regulated in response to LPS, suggesting unique roles during the sepsis cascade.     

Gene expression and production of the monokine induced by IFN-gamma (MIG), IFN-inducible T cell alpha chemoattractant (I-TAC), and IFN-gamma-inducible protein-10 (IP-10) chemokines by human neutrophils

Monokine induced by IFN-gamma (MIG), IFN-inducible T cell alpha chemoattractant (I-TAC), and IFN-gamma-inducible protein of 10 kDa (IP-10) are related members of the CXC chemokine subfamily that bind to a common receptor, CXCR3, and that are produced by different cell types in response to IFN-gamma. We have recently reported that human polymorphonuclear neutrophils (PMN) have the capacity to release IP-10. Herein, we show that PMN also have the ability to produce MIG and to express I-TAC mRNA in response to IFN-gamma in combination with either TNF-alpha or LPS. While IFN-gamma, alone or in association with agonists such as fMLP, IL-8, granulocyte (G)-CSF and granulocyte-macrophage (GM)-CSF, failed to influence MIG, IP-10, and I-TAC gene expression, IFN-alpha, in combination with TNF-alpha, LPS, or IL-1beta, resulted in a considerable induction of IP-10 release by neutrophils. Furthermore, IL-10 and IL-4 significantly suppressed the expression of MIG, IP-10, and I-TAC mRNA and the extracellular production of MIG and IP-10 in neutrophils stimulated with IFN-gamma plus either LPS or TNF-alpha. Finally, supernatants harvested from stimulated PMN induced migration and rapid integrin-dependent adhesion of CXCR3-expressing lymphocytes; these activities were significantly reduced by neutralizing anti-MIG and anti-IP-10 Abs, suggesting that they were mediated by MIG and IP-10 present in the supernatants. Since MIG, IP-10, and I-TAC are potent chemoattractants for NK cells and Th1 lymphocytes, the ability of neutrophils to produce these chemokines might contribute not only to the progression and evolution of the inflammatory response, but also to the regulation of the immune response.     

Discovery and optimization of a series of quinazolinone-derived antagonists of CXCR3

A series of quinazolinone-derived inhibitors of the CXCR3 receptor have been synthesized and their affinity for the receptor evaluated. Compounds were evaluated in a (125)I-IP10 displacement assay and in in vitro cell migration assays to IP10, ITAC, and MIG using human peripheral blood mononuclear cells.     

Chemokine production by rat macrophages stimulated with streptolysin O from Streptococcus pyogenes

The contribution of streptolysin O (SLO) from Streptococcus pyogenes to neutrophil infiltration in inflammatory lesions was determined by production of cytokine-induced neutrophil chemoattractant (CINC)-1, -2 and -3, and macrophage inflammatory protein (MIP)-1alpha by rat macrophages stimulated with SLO in culture. Active SLO induced the production of CINCs and MIP-1alpha in dose- and time-dependent manners. These inductions were ascertained by chemokine mRNA expression in macrophages. Streptolysin S was without effect. The SLO-cholesterol complex induced the chemokine production in proportion to the residual hemolytic activity of the complex. In addition, the effects of SLO on the chemokine production were confirmed by the injection of active SLO into the preformed air pouch on the back of rats. The infiltration of neutrophils into the pouch fluid (exudate) increased steadily with a lag phase of about 2 hr. The major chemokine found in exudates was MIP-1alpha but not CINCs. In this study, it became clear that active SLO, but not the inactive one, contributed to the production of MIP-1alpha and CINCs in the conditioned medium and in exudates.     

Decreased alveolar oxygen induces lung inflammation

Molecular mechanisms of the inflammatory reaction in hypoxia-induced lung injury are not well defined. Therefore, effects of alveolar hypoxia were studied in rat lungs, exposing rats to 10% oxygen over periods of 1, 2, 4, 6, and 8 h. An increase in the number of macrophages in bronchoalveolar lavage fluid of hypoxic animals was shown between 1 and 8 h. Extravasation of albumin was enhanced after 1 h and remained increased throughout the study period. NF-kappaB-binding activity as well as mRNA for TNF-alpha, macrophage inflammatory protein (MIP)-1beta, and monocyte chemoattractant protein (MCP)-1 were increased within the first 2 h of exposure to hypoxia. Hypoxia-inducible factor (HIF)-1alpha and intercellular adhesion molecule (ICAM)-1 mRNA were upregulated between 1 and 6 h. Elimination of alveolar macrophages by intratracheal application of liposome-encapsulated clodronate led to a decreased expression of NF-kappaB binding activity, HIF-1alpha, TNF-alpha, ICAM-1, and MIP-1beta. In summary, alveolar hypoxia induced macrophage recruitment, an increase in albumin leakage, and enhanced expression of inflammatory mediators, which were mainly macrophage dependent. Alveolar macrophages appear to have a prominent role in the inflammatory response in hypoxia-induced lung injury and the related upregulation of inflammatory mediators.     

Delayed expression of cytokines after reperfused myocardial infarction: possible trigger for cardiac dysfunction and ventricular remodeling

Previous studies have shown that 1 wk after permanent coronary artery ligation in rats, some cellular mechanisms involving TNF-alpha occur and contribute to the development of cardiac dysfunction and subsequent heart failure. The aim of the present study was to determine whether similar phenomena also occur after ischemia-reperfusion and whether cytokines other than TNF-alpha can also be involved. Anesthetized male Wistar rats were subjected to 1 h coronary occlusion followed by reperfusion. Cardiac geometry and function were assessed by echocardiography at days 5, 7, 8, and 10 postligation. Before death, heart function was assessed in vivo under basal conditions, as well as after volume overload. Finally, hearts were frozen for histoenzymologic assessment of infarct size and remodeling. The profile of cardiac cytokines was determined by ELISA and ChemiArray on heart tissue extracts. As expected, ischemia-reperfusion induced a progressive remodeling of the heart, characterized by left ventricular free-wall thinning and cavity dilation. Heart function was also decreased in ischemic rats during the first week after surgery. Interestingly, a transient and marked increase in TNF-alpha, IL-1beta, IL-6, cytokine-induced neutrophil chemoattractant (CINC) 2, CINC3, and macrophage inflammatory protein-3alpha was also observed in the myocardium of myocardial ischemia (MI) animals at day 8, whereas the expression of anti-inflammatory interleukins IL-4 and IL-10 remained unchanged. These results suggest that overexpression of proinflammatory cytokines occurring during the first week after ischemia-reperfusion may play a role in the adaptative process in the myocardium and contribute to early dysfunction and remodeling.     

Cytokine and chemokine mRNA expression in neutrophils from CBA/NSlc mice infected with Plasmodium berghei ANKA that induces experimental cerebral malaria.

To investigate the role of neutrophils in experimental cerebral malaria (ECM), in a previous study we found that early neutrophil depletion prevented the development of ECM and down regulated the expression of Th1 cytokines in the brain. To further clarify the mechanisms responsible for these findings, in the present study, using RT-PCR, we examined the expression of cytokine and chemokine mRNAs in neutrophils and macrophages after PbA infection. We found that, after infection, neutrophils not only expressed cytokines IL-2, IL-12p40, IL-18, IFN-gamma and TNF-alpha mRNAs, but also mRNAs for Th1 chemoattractive chemokines, monokine-induced by IFN-gamma (MIG), macrophage-inflammatory protein-1alpha (MIP-1alpha) and IFN-gamma inducible protein-10 (IP-10). Neutrophil depletion down regulated the expression of IL-18 and MIG mRNAs in macrophages, but did not affect the expression of IFN-gamma, TNF-alpha, MIP-1alpha and IP-10 mRNAs. Therefore, this study confirms our hypothesis that neutrophils may play a role in the pathogenesis of ECM via their expression of cytokines or chemokines.     

Toll-like receptor (TLR) 2-9 agonists-induced cytokines and chemokines: I. Comparison with T cell receptor-induced responses

The cells of innate and adaptive immunity, although activated by different ligands, engage in cross talk to ensure a successful immune outcome. To better understand this interaction, we examined the demographic picture of individual TLR (TLRs 2-9) -driven profiles of eleven cytokines (IFN-alpha/beta, IFN-gamma, IL-12p40/IL-12p70, IL-4, 1L-13, TNF-alpha, IL-1beta, IL-2, IL-10) and four chemokines (MCP-1, MIP1beta, IL-8, and RANTES), and compared them with direct T-cell receptor triggered responses in an assay platform using human PBMCs. We find that T-cell activation by a combination of anti-CD3/anti-CD28/PHA induced a dominant IL-2, IL-13, and Type-II interferon (IFN-gamma) response without major IL-12 and little Type-I interferon (IFN-alphabeta) release. In contrast, TLR7 and TLR9 agonists induced high levels of Type-I interferons. The highest IFN-gamma levels were displayed by TLR8 and TLR7/8 agonists, which also induced the highest levels of pro-inflammatory cytokines IL-12, TNF-alpha, and IL-1beta. Amongst endosomal TLRs, TLR7 displayed a unique profile producing weak IL-12, IFN-gamma, TNF-alpha, IL-1beta, and IL-8. TLR7 and TLR9 resembled each other in their cytokine profile but differed in MIP-1beta and MCP1 chemokine profiles. Gram positive (TLR2, TLR2/6) and gram negative (TLR4) pathogen-derived TLR agonists displayed significant similarities in profile, but not in potency. TLR5 and TLR2/6 agonists paralleled TLR2 and TLR4 in generating pro-inflammatory chemokines MCP-1, MIP-1beta, RANTES, and IL-8 but yielded weak TNF-alpha and IL-1 responses. Taken together, the data show that diverse TLR agonists, despite their operation through common pathways induce distinct cytokine/chemokine profiles that in turn have little or no overlap with TCR-mediated response.