BACKGROUND: Dendritic cells (DCs) play a critical role not only in the initiation of immune responses, but also in the induction of immune tolerance. In an effort to regulate immune responses through the modulation of antigen presenting cell (APC) function of DCs, we searched for and characterized APC function modulators from natural products. METHODS: DCs were cultured in the presence of propolis components, WP and CP, and then examined for their ability to present exogenous antigen in association with major histocompatibility complexes (MHC). RESULTS: WP and CP inhibited class I MHC-restricted presentation of exogenous antigen (cross-presentation) in a DC cell line, DC2.4 cells, and DCs generated from bone marrow cells with GM-CSF and IL-4. The inhibitory activity of WP and CP appeared to be due not only to inhibition of phagocytic activity of DCs, but also to suppression of expression of MHC molecules on DCs. We also examined the effects of WP and CP on T cells. Interestingly, WP and CP increased IL-2 production from T cells. CONCLUSION: These results demonstrate that WP and CP inhibit MHC-restricted presentation of exogenous antigen through down-regulation of phagocytic activity and suppression of expression of MHC molecules on DCs.
Antigen Presentation ; Biological Products ; Bone Marrow Cells ; Cell Line ; Dendritic Cells* ; Down-Regulation ; Granulocyte-Macrophage Colony-Stimulating Factor ; Immune Tolerance ; Interleukin-2 ; Interleukin-4 ; Major Histocompatibility Complex* ; Propolis* ; T-Lymphocytes

BACKGROUND: It has been recently noticed that type 2 diabetes (T2D), one of the most common metabolic diseases, causes a chronic low-grade inflammation and activation of the innate immune system that are closely involved in the pathogenesis of T2D. Cordyceps militaris, a traditional medicinal mushroom, produces a component compound, cordycepin (3'-deoxyadenosine). Cordycepin has been known to have many pharmacological activities including immunological stimulating, anti-cancer, and anti-infection activities. The molecular mechanisms of cordycepin in T2D are not clear. In the present study, we tested the role of cordycepin on the anti-diabetic effect and anti-inflammatory cascades in LPS-stimulated RAW 264.7 cells. METHODS: We confirmed the levels of diabetes regulating genes mRNA and protein of cytokines through RT-PCR and western blot analysis and followed by FACS analysis for the surface molecules. RESULTS: Cordycepin inhibited the production of NO and pro-inflammatory cytokines such as IL-1beta, IL-6, and TNF-alpha in LPS-activated macrophages via suppressing protein expression of pro-inflammatory mediators. T2D regulating genes such as 11beta-HSD1 and PPARgamma were decreased as well as expression of co-stimulatory molecules such as ICAM-1 and B7-1/-2 were also decreased with the increment of its concentration. In accordance with suppressed pro-inflammatory cytokine production lead to inhibition of diabetic regulating genes in activated macrophages. Cordycepin suppressed NF-kappaB activation in LPS-activated macrophages. CONCLUSION: Based on these observations, cordycepin suppressed T2D regulating genes through the inactivation of NF-kappaB dependent inflammatory responses and suggesting that cordycepin will provide potential use as an immunomodulatory agent for treating immunological diseases.
11-beta-Hydroxysteroid Dehydrogenase Type 1 ; Agaricales ; Blotting, Western ; Cordyceps ; Cytokines ; Deoxyadenosines ; Immune System ; Inflammation ; Intercellular Adhesion Molecule-1 ; Interleukin-6 ; Macrophages ; Metabolic Diseases ; NF-kappa B ; PPAR gamma ; RNA, Messenger ; Tumor Necrosis Factor-alpha

BACKGROUND: Chronic low grade inflammation is closely linked to type II diabetes, obesity, and atherosclerosis. Macrophages play a key role in the regulation of pro- or anti-inflammatory actions at the lesion sites of disease. Components of cordyceps militaris, cordycepin and adenosine, have been used for the modulation of inflammatory diseases. The effects of cordycepin in the modulation of macrophages have yet to be elucidated. We investigated the effects of cordycepin and adenosine on the morphological changes of macrophages under the inflammatory condition of LPS and an anti-inflammatory condition involving high concentrations of adenosine. METHODS: We confirmed the mRNA levels of the M1/M2 cytokine genes through RT-PCR and morphological change. RESULTS: LPS-activated macrophages returned to their inactivated original shape, i.e., they looked like naive macrophages, through the treatment with high concentrations of cordycepin (40 microgram/ml). LPS and adenosine activated macrophages also returned to their original inactivated shapes after cordycepin treatment; however, at relatively higher levels of cordycepin than adenosine. This change did not occur with relatively low concentrations of cordycepin. Adenosine down-regulated the gene expression of M1 cytokines (IL-1beta, TNF-alpha) and chemokines (CX3CR1, RANTES), as well as cordycepin. Additionally, M2 cytokines (IL-10, IL-1ra, TGF-beta) were up-regulated by both cordycepin and adenosine. CONCLUSION: Based on these observations, both cordycepin and adenosine regulated the phenotypic switch on macrophages and suggested that cordycepin and adenosine may potentially be used as immunomodulatory agents in the treatment of inflammatory disease.
Adenosine ; Atherosclerosis ; Chemokines ; Cordyceps ; Cytokines ; Deoxyadenosines ; Gene Expression ; Inflammation ; Interleukin 1 Receptor Antagonist Protein ; Macrophages ; Obesity ; RNA, Messenger

BACKGROUND: Cordyceps militaris has been used in traditional medicine to treat numerous diseases and has been reported to possess both antitumor and immunomodulatory activities in vitro and in vivo. However, the pharmacological and biochemical mechanisms of Cordyceps militaris extract (CME) on macrophages have not been clearly elucidated. In the present study, we examined how CME induces the production of proinflammatory cytokines, transcription factor, and the expression of co-stimulatory molecules. METHODS: We confirmed the mRNA and protein levels of proinflammatory cytokines through RT-PCR and western blot analysis, followed by a FACS analysis for surface molecules. RESULTS: CME dose dependently increased the production of NO and proinflammatory cytokines such as IL-1beta, IL-6, TNF-alpha, and PGE(2), and it induced the protein levels of iNOS, COX-2, and proinflammatory cytokines in a concentration-dependent manner, as determined by western blot and RT-PCR analysis, respectively. The expression of co-stimulatory molecules such as ICAM-1, B7-1, and B7-2 was also enhanced by CME. Furthermore, the activation of the nuclear transcription factor, NF-kappaB in macrophages was stimulated by CME. CONCLUSION: Based on these observations, CME increased proinflammatory cytokines through the activation of NF-kappaB, further suggesting that CME may prove useful as an immune-enhancing agent in the treatment of immunological disease.
Blotting, Western ; Cordyceps ; Cytokines ; Immune System Diseases ; Intercellular Adhesion Molecule-1 ; Interleukin-6 ; Macrophages ; Medicine, Traditional ; NF-kappa B ; RNA, Messenger ; Transcription Factors ; Tumor Necrosis Factor-alpha

BACKGROUND: Cordyceps militarys water extract (CME) has been reported to exert antitumor and immunomodulatory activities in vivo and in vitro. However, the therapeutic mechanism has not yet been elucidated. In this study, we examined the effects of CME on the antigen presenting function of antigen presenting cells (APCs). METHODS: Dendritic cells (DCs) were cultured in the presence of CME, and then allowed to phagocytose microspheres containing ovalbumin (OVA). After washing and fixing the efficacy of OVA, peptide presentation by DCs were evaluated using CD8 and CD4 T cells. Also, we confirmed the protein levels of proinflammatory cytokines through western blot analysis. RESULTS: CME enhanced both MHC class I and class II-restricted presentation of OVA in DCs. In addition, the expression of both MHC class I and II molecules was enhanced, but there was no changes in the phagocytic activity of exogenous OVA. Furthermore, CME induced the protein levels of iNOS, COX-2, proinflammatory cytokines, and nuclear p65 in a concentration-dependent manner, as determined by western blot. CONCLUSION: These results provide an understanding of the mechanism of the immuno-enhancing activity of CME on the induction of MHC-restricted antigen presentation in relation to their actions on APCs.
Antigen Presentation ; Antigen-Presenting Cells ; Blotting, Western ; Cordyceps ; Cytokines ; Dendritic Cells ; Microspheres ; Ovalbumin ; Ovum ; T-Lymphocytes ; Water