Development of Exhausted Memory Monocytes and Underlying Mechanisms.

Pathogenic inflammation and immuno-suppression are cardinal features of exhausted monocytes increasingly recognized in septic patients and murine models of sepsis. However, underlying mechanisms responsible for the generation of exhausted monocytes have not been addressed. In this report, we examined the generation of exhausted primary murine monocytes through prolonged and repetitive challenges with high dose bacterial endotoxin lipopolysaccharide (LPS). We demonstrated that repetitive LPS challenges skew monocytes into the classically exhausted Ly6Chi population, and deplete the homeostatic non-classical Ly6Clo population, reminiscent of monocyte exhaustion in septic patients. scRNAseq analyses confirmed the expansion of Ly6Chi monocyte cluster, with elevation of pathogenic inflammatory genes previously observed in human septic patients. Furthermore, we identified CD38 as an inflammatory mediator of exhausted monocytes, associated with a drastic depletion of cellular NAD+; elevation of ROS; and compromise of mitochondria respiration, representative of septic monocytes. Mechanistically, we revealed that STAT1 is robustly elevated and sustained in LPS-exhausted monocytes, dependent upon the TRAM adaptor of the TLR4 pathway. TRAM deficient monocytes are largely resistant to LPS-mediated exhaustion, and retain the non-classical homeostatic features. Together, our current study addresses an important yet less-examined area of monocyte exhaustion, by providing phenotypic and mechanistic insights regarding the generation of exhausted monocytes.

Dissolvable microneedles based on Panax notoginseng polysaccharide for transdermal drug delivery and skin dendritic cell activation.

This work explored the feasibility of using biological polysaccharide to fabricate dissolvable microneedles (MNs) for the purpose of transdermal drug delivery and skin dendritic cell (DC) activation. Panax notoginseng polysaccharide (PNPS), a naturally derived immunoactive macromolecule, was used to fabricate dissolvable MNs. The prepared PNPS MNs showed a satisfactory mechanical strength and a skin penetration depth. By Franz diffusion cell assay, the PNPS MNs demonstrated a high transdermal delivery amount of model drugs. Furthermore, with the assistance of MNs, PNPS easily penetrated across the stratum corneum and target ear skin DCs, activating the maturation and migration of immunocytes by increasing the expressions of CD40, CD80, CD86, and MHC II of skin DCs. Consequently, the matured DCs migrated to the auricular draining lymph nodes and increased the proportions of CD4+ T and CD8+ T cells. Thus, PNPS might be a promising biomaterial for transdermal drug delivery, with adjuvant potential.

Thymoquinone ameliorates Pachycondyla sennaarensis venom-induced acute toxic shock in male rats.

BACKGROUND: For many decades, the sting of Samsun ant (Pachycondyla sennaarensis) has been a serious clinical challenge for the people living in some of the major Middle East and Asian countries. In the present study, the therapeutic potential of Nigella sativa derived plant extract component, thymoquinone (TQ) has been tested against the Samsun ant venom (SAV) at the toxic dose in the rats. METHODS: The adult male rats were divided into four groups (n = 10): control, SAV treated, SAV + TQ treated and TQ alone treated. It was found that the sub-lethal dose of SAV alters not only many of the kidney and liver function markers but also induces oxidative stress in the animals. Moreover, the SAV also disturbs various immunological parameters including expression of PMNs, CD-80, CD-86, interleukins and other cytokines compromising the affected organism towards mild to severe allergic reactions including life-risking anaphylaxis. RESULTS: The plant extract, TQ, effectively restores many of the biochemical and oxidative stress parameters comparable to the normal concomitant with improving the immunological aspects that might attributive in relieving from SAV-induced toxicity and allergic reactions in the affected organism to a greater extent. CONCLUSION: Hence, TQ has an excellent antidote property against SAV-induced toxicities in vivo. Although the study is a vivid indication of the potential therapeutic potential of TQ against the SAV induced in vivo toxicity, yet the actual mechanism of interaction translating the toxicity amelioration warrants further investigations.

Gastrodin, a traditional Chinese medicine monomer compound, can be used as adjuvant to enhance the immunogenicity of melanoma vaccines.

Gastrodin (GAS) is a Chinese medicine with wide application for the treatment of nervous system disease. Previous studies reported that GAS exhibited non-specific immunomodulatory activities. To explore the effects of GAS as a vaccine adjuvant, the expression levels of CD80, CD86, MHCI and MHCII activated markers were detected after GAS treatment in vitro and in vivo, and the expression levels of IL-2 and TNF-α in splenocytes were detected after GAS treatment in vivo. Besides, the expression levels of IL-2 and IFN-γ in CD4+T cells and perforin, TNF-α and IFN-γ in CD8+T cells were detected. The effects of GAS on the survival rate and tumor size of tumor-challenged mice and the effect of cytotoxicity on CD8+T cells were also investigated. Our data showed that GAS ameliorated CD8+T cell mediated immune response and significantly improved protection of tumor-challenged animals. The results demonstrated that GAS is a potential adjuvant contributing to anticancer immunomodulation.

The effect of 808 nm and 905 nm wavelength light on recovery after spinal cord injury.

We investigated the effect of a Multiwave Locked System laser (with a simultaneous 808 nm continuous emission and 905 nm pulse emission) on the spinal cord after spinal cord injury (SCI) in rats. The functional recovery was measured by locomotor tests (BBB, Beam walking, MotoRater) and a sensitivity test (Plantar test). The locomotor tests showed a significant improvement of the locomotor functions of the rats after laser treatment from the first week following lesioning, compared to the controls. The laser treatment significantly diminished thermal hyperalgesia after SCI as measured by the Plantar test. The atrophy of the soleus muscle was reduced in the laser treated rats. The histopathological investigation showed a positive effect of the laser therapy on white and gray matter sparing. Our data suggests an upregulation of M2 macrophages in laser treated animals by the increasing number of double labeled CD68+/CD206+ cells in the cranial and central parts of the lesion, compared to the control animals. A shift in microglial/macrophage polarization was confirmed by gene expression analysis by significant mRNA downregulation of Cd86 (marker of inflammatory M1), and non-significant upregulation of Arg1 (marker of M2). These results demonstrated that the combination of 808 nm and 905 nm wavelength light is a promising non-invasive therapy for improving functional recovery and tissue sparing after SCI.

Polysaccharide rich extract (PRE) from Tinospora cordifolia inhibits the intracellular survival of drug resistant strains of Mycobacterium tuberculosis in macrophages by nitric oxide induction.

Plethora of clinical and scientific information obtained in recent past has strengthened the idea that targeting critical constituents of host immune system may have beneficial outcomes for the treatment of tuberculosis. Macrophages being the primary host for Mycobacterium tuberculosis, offer an attractive target for modulation. Owing to their negligible toxicity, plant derived polysaccharides with the ability to activate macrophages; are suitable candidates for immunomodulation. In the present study, effects of polysaccharide rich extract (PRE) isolated from Tinospora cordifolia, on the survival of intracellular MTB strains and activation of macrophages were investigated. PRE treatment up regulated the expression of pro-inflammatory cytokines such as IL-ß, TNF-α, IL-6, IL-12, and IFN-γ in RAW 264.7 cell line. Up regulation in the expression of NOS2 was observed along with concomitant enhanced nitric oxide production post PRE treatment. Surface expression of MHC-II and CD-86 was up regulated after PRE treatment. Above results suggested the classical activation of macrophages by PRE treatment. Furthermore, PRE treatment led to the activation of all the three classes of MAPK i.e p38, ERK and JNK MAPKs. Further, PRE up regulated the expression of cytokines, NOS-2, MHC-II and CD-86 in MTB infected macrophages. PRE treatment inhibited the intracellular survival of drug resistant MTB in macrophages which was partially attributed to PRE mediated NO induction. Thus our data demonstrate classical activation of macrophages by PRE treatment and killing of intracellular MTB by NO induction.

Marina crystal minerals (MCM) activate human dendritic cells to induce CD4+ and CD8+ T cell responses in vitro.

Marina crystal minerals (MCM) are a mixture that contains crystallized minerals along with trace elements extracted from seawater. It is a nutritional supplement that is capable of enhancing natural killer (NK) cell activity and increasing T and B cell proliferation in humans post ingestion. However, its effect on dendritic cells (DCs), the cells that bridge innate and adaptive immunity, is not yet known. In this study, we examine the stimulatory effects of MCM on DCs' maturation and function in vitro. Human monocyte-derived DCs were treated with MCM at two different concentrations (10 and 20 µg/mL) for 24 h. Results showed that MCM treatment activated DCs in a dose-dependent fashion. It caused the upregulation of costimulatory molecules CD80, CD86, and HLA-DR, and prompted the production of DC cytokines, including interleukin (IL)-6, IL-10, tumor necrosis factor (TNF)-α, and IL-1ß, and chemokines (monocyte chemotactic protein-1 (MCP-1)) and interferon-gamma-inducible protein-10 (IP-10). In addition, activated DCs primed CD4+ T cells to secrete significant amounts of interferon gamma (IFN-γ), and they also stimulated CD8+ T cells to express higher amounts of CD107a. These results indicate that MCM is a potentially powerful adjuvant, from natural materials, that activates human DCs in vitro and therefore may suggest its possible use in immune-based therapies against cancer and viral infections.

Targeted delivery of p-coumaric acid encapsulated mannosylated liposomes to the synovial macrophages inhibits osteoclast formation and bone resorption in the rheumatoid arthritis animal model.

The current study aimed to target the delivery of p-coumaric acid (CA), a dietary polyphenol to the synovial macrophages of AIA rats via mannose incorporated liposomal delivery system (ML) with reference to osteoclastogenesis and bone resorption. In vivo imaging and in vitro drug release study indicated the efficiency of mannosylated liposomes to localize at the site of inflammation and increased sustain drug release respectively. Morphological assessment of isolated synovial macrophages with respect to CD86 (synovial macrophages) and CD51 (pre-/osteoclast) indicated that p-coumaric acid encapsulated mannosylated liposomes (ML-CA) inhibited the osteoclasts differentiation. ML-CA treatment inhibited the TRAP staining, downregulated the expression of MMP-9 and NFATc1 and inflammatory cytokines. The ex-vivo study specified the ability of CA to induce the OPG production in bone marrow stromal cell triggered macrophage-osteoclasts differentiation and to preserve the calcium content. Taken together, our results demonstrated that ML-CA could intervene in the osteoclast formation.

Effect of isoliquiritigenin for the treatment of atopic dermatitis-like skin lesions in mice.

Atopic dermatitis (AD) is a common chronic inflammatory skin disease characterized with high heterogeneity. Recent studies have suggested that it is driven by both terminal keratinocyte differentiation defects and type 2 immune responses. The mainstay steroid topical therapy has severe side effect and new treatment is in demand. Isoliquiritigenin (ISLG) is a small phenolic bioactive molecule from licorice that has shown multiple pharmacological effects against cancer, inflammatory disorder, and cardiovascular diseases. ISLG was evaluated in AD-like lesion model induced by the repetitive application of 2,4-dinitrochlorobenzene (DNCB) in BALB/c mice. Overall symptom score, serological and molecular changes of the skin lesions were evaluated. ISLG could ameliorate the overall manifestation of AD-like symptoms including scratching behavior incidence and skin lesion severity. At blood level, ISLG significantly suppressed the DNCB-induced IgE and Th2 cytokines up-regulation. At skin lesion site, ISLG also inhibited DNCB-induced pro-inflammatory cytokines like TNF-α, IL-6 as well as IL-4 expressions. In a human monocyte model THP-1, ISLG suppressed the up-regulation of CD86 and CD54 and abolished the DNCB-induced p38-α and ERK activation, suggesting a molecular mechanism for ISLG therapy. This study indicated that ISLG could be a potential therapeutic agent for the treatment of AD.

Curcumin ameliorates experimental autoimmune myasthenia gravis by diverse immune cells.

Curcumin is a traditional Asian medicine with diverse immunomodulatory properties used therapeutically in the treatment of many autoimmune diseases. However, the effects of curcumin on myasthenia gravis (MG) remain undefined. Here we investigated the effects and potential mechanisms of curcumin in experimental autoimmune myasthenia gravis (EAMG). Our results demonstrated that curcumin ameliorated the clinical scores of EAMG, suppressed the expression of T cell co-stimulatory molecules (CD80 and CD86) and MHC class II, down-regulated the levels of pro-inflammatory cytokines (IL-17, IFN-γ and TNF-α) and up-regulated the levels of the anti-inflammatory cytokine IL-10, shifted the balance from Th1/Th17 toward Th2/Treg, and increased the numbers of NKR-P1(+) cells (natural killer cell receptor protein 1 positive cells, including NK and NKT cells). Moreover, the administration of curcumin promoted the differentiation of B cells into a subset of B10 cells, increased the anti-R97-166 peptide IgG1 levels and decreased the relative affinity indexes of anti-R97-116 peptide IgG. In summary, curcumin effectively ameliorate EAMG, indicating that curcumin may be a potential candidate therapeutic agent for MG.

In vitro inhibitory effects of thymol and carvacrol on dendritic cell activation and function.

CONTEXT: Thyme has been used in traditional medicine for medicinal purposes since ancient times. OBJECTIVE: The objective of this study was to investigate the effects of thymol and carvacrol as two major constituents of thyme on dendritic cells (DCs) maturation and T cell activation. MATERIALS AND METHODS: Splenic DCs were treated with non-cytotoxic concentrations of the components and then analyzed for MHC II, CD86, and CD40 expression by flow cytometry. The effects of compounds on mitogenic, as well as allogenic T cell responses in mixed lymphocyte culture (MLR) and the release of cytokines were investigated. RESULTS: At 0.1 µg/ml, reduced mean fluorescent intensity (MFI) of CD86 for thymol (80.3 ± 0.2% of untreated control) and CD40 for carvacrol (79.5 ± 0.14%) was observed (p < 0.001). Decreased mitogenic T cell proliferation by thymol [proliferation index (PI) from 0.93 ± 0.11 at 1 µg/ml to 0.42 ± 0.16 at 100 µg/ml (p < 0.01)] and carvacrol [PI from 1.08 ± 0.3 at 1 µg/ml to 0.28 ± 0.1 at 100 µg/ml (p < 0.001)] was seen. Ten micrograms/ml thymol (PI, 0.85 ± 0.04) and carvacrol (PI, 0.89 ± 0.03) inhibited allogenic T cell response (p < 0.05). Decreased IFN-γ level in MLR supernatant from 1441 ± 27.7 pg/ml in untreated cells to 944 ± 32.1 at 10 µg/ml of thymol and of carvacrol (886 ± 31.7 pg/ml) (p < 0.01) was found. IL-4 levels were decreased in the presence of both compounds (p < 0.01). CONCLUSION: These data showed the suppressive effects of thymol and carvacrol on DCs maturation and function, as well as T cell responses.

Optimization of the THP-1 activation assay to detect pharmaceuticals with potential to cause immune mediated drug reactions.

Despite important impacts of systemic hypersensitivity induced by pharmaceuticals, for such endpoint no reliable preclinical approaches are available. We previously established an in vitro test to identify contact and respiratory allergens based on interleukin-8 (IL-8) production in THP-1 cells. Here, we challenged it for identification of pharmaceuticals associated with systemic hypersensitivity reactions, with the idea that drug sensitizers share common mechanisms of cell activation. Cells were exposed to drugs associated with systemic hypersensitivity reactions (streptozotocin, sulfamethoxazole, neomycin, probenecid, clonidine, procainamide, ofloxacin, methyl salicylate), while metformin was used as negative drug. Differently to chemicals, drugs tested were well tolerated, except clonidine and probenecid, with no signs of cytotoxicity up to 1-2mg/ml. THP-1 activation assay was adjusted, and conditions, that allow identification of all sensitizing drugs tested, were established. Next, using streptozotocin and selective inhibitors of PKC-ß and p38 MAPK, two pathways involved in chemical allergen-induced cell activation, we tested the hypothesis that similar pathways were also involved in drug-induced IL-8 production and CD86 upregulation. Results indicated that drugs and chemical allergens share similar activation pathways. Finally, we made a structure-activity hypothesis related to hypersensitivity reactions, trying to individuate structural requisite that can be involved in immune mediated adverse reactions.

Irisflorentin modifies properties of mouse bone marrow-derived dendritic cells and reduces the allergic contact hypersensitivity responses.

Irisflorentin is an isoflavone component derived from the roots of Belamcanda chinensis (L.) DC. In traditional Chinese medicine, this herb has pharmacological properties to treat inflammatory disorders. Dendritic cells (DCs) are crucial modulators for the development of optimal T-cell immunity and maintenance of tolerance. Aberrant activation of DCs can induce harmful immune responses, and so agents that effectively improve DC properties have great clinical value. We herein investigated the effects of irisflorentin on lipopolysaccharide (LPS)-stimulated maturation of mouse bone marrow-derived DCs in vitro and in the contact hypersensitivity response (CHSR) in vivo. Our results demonstrated that treatment with up to 40 µM irisflorentin does not cause cellular toxicity. Irisflorentin significantly lessened the proinflammatory cytokine production (tumor necrosis factor-α, interleukin-6, and interleukin-12p70) by LPS-stimulated DCs. Irisflorentin also inhibited the expression of LPS-induced major histocompatibility complex class II and costimulatory molecules (CD40 and CD86) on LPS-stimulated DCs. In addition, irisflorentin diminished LPS-stimulated DC-elicited allogeneic T-cell proliferation. Furthermore, irisflorentin significantly interfered with LPS-induced activation of IκB kinase, c-Jun N-terminal kinase, and p38, as well as the nuclear translocation of NF-κB p65. Subsequently, treatment with irisflorentin obviously weakened 2,4-dinitro-1-fluorobenzene-induced delayed-type hypersensitivity. These findings suggest new insights into the role of irisflorentin as an immunotherapeutic adjuvant through its capability to modulate the properties of DCs.

Efficacy of Zhuling polyporus polysaccharide with BCG to inhibit bladder carcinoma.

There is growing interest in reducing Bacille Calmette-Guerin (BCG) side effects while keeping intact its therapeutic efficacy. In the present study, we evaluated the efficacy of Sclerotia of Polyporus umbellatus FRIES (Zhuling) and its main ingredient Polyporus Polysaccharide (PPS) to attenuate side effects of BCG therapy in vivo. The results show that bladder cancer development in model rats exhibited significantly reduced cancer invasiveness with Zhuling PPS combined with BCG. Flow cytometric (FCM) analysis showed expression of costimulatory molecules CD86, CD40, and TLR4/CD14 significantly increased with Zhuling PPS in combination with BCG. Similarly, immunohistochemical analysis revealed stronger CD86 and CD40 staining. Our findings show Zhuling PPS strongly reduced side effects and displayed synergistic effects during BCG instillation in rat bladder cancer models. The findings also suggest that the attenuation effect may result from direct activation of dendritic cell (DC) TLR4.

Antigen specific immune enhancement of innate and acquired immunity by pearl in ashed form.

The present study evaluated mineral compound, pearl in ashed form [PAF], for its potential as oral immunomodulator. ICP-MS, atomic absorption spectroscopy, CHNS analysis and XRD analysis were used for characterization of PAF. Surface antigen markers (TLR-2/4 and CD-80/86) were studied by flow cytometry. At dose concentration of 25, 50, 100 and 500 µg/kg body wt., administrated orally for 10 days, TLR-2 expression on murine peritoneal macrophage increased while TLR-4 expression was reduced as compared to control. There was an increase in OVA and mitogen (Con-A) specific lymphocyte proliferation in OVA immunized mice. Also, level of both Th1 (IL-2/IFN-γ) and Th2 (IL-4/IL-10) cytokines, and level and titer of total IgG, IgG1, IgG2a and IgG2b of OVA immunized mice significantly increased. The level of Inflammatory cytokines (IL-1ß and TNF-α) did not increase significantly. Enhancement in T and B cell immune responses may be possibly due to significantly enhanced expression of CD-80 and CD-86 co-stimulatory signals as observed using flow cytometry. Also, enhanced phagocytic activity and DTH response exhibit stimulatory effect of PAF on innate and cell mediated immune response. Histopathological analysis of liver, kidney and spleen and analysis of other toxicity parameters, such as effect on body weight, lymphoid organ weight and cellularity, revealed PAF to exhibit no toxic effects. PAF seems to be a promising balanced Th1 and Th2 directing immunomodulator, possibly activating TLR2 through TIR domain-containing adaptor inducing interferon ß (TRIF)-dependent pathway that leads to T-cell activation and promotes effective immune responses and may find useful application clinically.

Glatiramer acetate (copaxone) modulates platelet activation and inhibits thrombin-induced calcium influx: possible role of copaxone in targeting platelets during autoimmune neuroinflammation.

BACKGROUND: Glatiramer acetate (GA, Copaxone, Copolymer-1) is an FDA approved drug for the treatment of MS and it is very effective in suppressing neuroinflammation in experimental autoimmune encephalitis (EAE), an animal model of MS. Although this drug was designed to inhibit pathogenic T cells, the exact mechanism of EAE/MS suppression by GA is still not well understood. Previously we presented evidence that platelets become activated and promote neuroinflammation in EAE, suggesting a possible pathogenic role of platelets in MS and EAE. We hypothesized that GA could inhibit neuroinflammation by affecting not only immune cells but also platelets. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the effect of GA on the activation of human platelets in vitro: calcium influx, platelet aggregation and expression of activation markers. Our results in human platelets were confirmed by in-vitro and in-vivo studies of modulation of functions of platelets in mouse model. We found that GA inhibited thrombin-induced calcium influx in human and mouse platelets. GA also decreased thrombin-induced CD31, CD62P, CD63, and active form of αIIbß3 integrin surface expression and formation of platelet aggregates for both mouse and human platelets, and prolonged the bleeding time in mice by 2.7-fold. In addition, we found that GA decreased the extent of macrophage activation induced by co-culture of macrophages with platelets. CONCLUSIONS: GA inhibited the activation of platelets, which suggests a new mechanism of GA action in suppression of EAE/MS by targeting platelets and possibly preventing their interaction with immune cells such as macrophages. Furthermore, the reduction in platelet activation by GA may have additional cardiovascular benefits to prevent thrombosis.

Characterization of beta-tricalcium phosphate as a novel immunomodulator.

Calcium phosphate (CaP) ceramics including hydroxyapatite (HA) and beta-tricalcium phosphate (ß-TCP) have been widely used for bone substitution in orthopedic, maxillofacial and dental surgery, as well as in tumor resections. CaP particles are also known to cause inflammatory responses, which are thought to be an unfavorable characteristic of prosthetic coating materials. On the other hand, the immunostimulatory effect of ß-TCP induces an anti-tumor effect in xenograft tumor models in athymic mice. To date, in depth analysis of the biological effects of ß-TCP has not been studied in mice. In the present study, in vivo biological effects of ß-TCP were investigated by subcutaneously injecting ß-TCP particles into mice. This induced extensive migration of immune cells to the area surrounding the injection. In addition, we found that in vitro treatment with ß-TCP in murine monocyte/macrophage cells (J774A.1) induced up-regulation of surface expression of CD86, and increased production of TNF-α, MIP-1α, and sICAM-1. Furthermore, conditioned medium from J774A.1 cells treated with ß-TCP facilitated migration of murine splenocytes in a transwell migration assay. These findings clarify that ß-TCP induces an immunostimulatory effect in mice, and suggest a potential for ß-TCP as a novel adjuvant for cancer therapy.

Dietary wolfberry supplementation enhances the protective effect of flu vaccine against influenza challenge in aged mice.

Current vaccines for influenza do not fully protect the aged against influenza infection. Although wolfberry (goji berry) has been shown to improve immune response, including enhanced antibody production, after vaccination in the aged, it is not known if this effect would translate to better protection after influenza infection, nor is its underlying mechanism well understood. To address these issues, we conducted a study using a 2 × 2 design in which aged male mice (20-22 mo) were fed a control or a 5% wolfberry diet for 30 d, then immunized with an influenza vaccine or saline (control) on days 31 and 52 of the dietary intervention, and finally challenged with influenza A/Puerto Rico/8/34 virus. Mice fed wolfberry had higher influenza antibody titers and improved symptoms (less postinfection weight loss) compared with the mice treated by vaccine alone. Furthermore, an in vitro mechanistic study showed that wolfberry supplementation enhanced maturation and activity of antigen-presenting dendritic cells (DCs) in aged mice, as indicated by phenotypic change in expression of DC activation markers major histocompatibility complex class II, cluster of differentiation (CD) 40, CD80, and CD86, and functional change in DC production of cytokines interleukin-12 and tumor necrosis factor-α as well as DC endocytosis. Also, adoptive transfer of wolfberry-treated bone marrow DCs (loaded with ovalbumin(323-339)-peptide) promoted antigen-specific T cell proliferation as well as interleukin-4 and interferon-γ production in CD4(+) T cells. In summary, our data indicate that dietary wolfberry enhances the efficacy of influenza vaccination, resulting in better host protection to prevent subsequent influenza infection; this effect may be partly attributed to improved DC function.

Tanshinone II A inhibits dendritic cell-mediated adaptive immunity: potential role in anti-atherosclerotic activity.

OBJECTIVE: Antigen-presenting cells such as monocytes and dendritic cells (DCs) stimulate T-cell proliferation and activation during adaptive immunity. This cellular interaction plays a role in the growth of atherosclerotic plaques. Tanshinone II A (TSN) had been shown to decrease the growth of atherosclerotic lesions. We therefore investigated the ability of TSN to inhibit human monocyte-derived DCs and their T-cellstimulatory capacity. METHODS: DCs derived from human monocytes cultured with recombinant human interleukin (IL)-4 and recombinant human granulocyte-macrophage colony-stimulating factor were co-cultured with TSN and lipopolysaccharide for 48 h. Phosphate-buffered saline was used as a negative control. Activation markers and the capacity of DCs for endocytosis were measured by flow cytometry, and proinflammatory cytokines were measured by enzyme-linked immunosorbent assays. DCs were co-cultured with lymphocytes to measure T-cell proliferation and IL-2 secretion by mixed lymphocyte reactions. RESULTS: TSN dose-dependently attenuated DC expression of costimulatory molecules (CD86), and decreased expression of major histocompatibility complex class II (human loukocyte antigen-DR) and adhesion molecules (CD54). Moreover, TSN reduced secretion of the proinflammatory cytokines IL-12 and IL-1 by human DCs, and restored the capacity for endocytosis. Finally, TSN-preincubated DCs showed a reduced capacity to stimulate T-cell proliferation and cytokine secretion. CONCLUSIONS: TSN inhibits DC maturation and decreases the expression of proinflammatory cytokines, while impairing their capacity to stimulate T-cell proliferation and cytokine secretion. These effects may contribute to the influence of TSN on the progression of atherosclerotic lesions.

Effects of ex vivo γ-tocopherol on airway macrophage function in healthy and mild allergic asthmatics.

Elevated inflammation and altered immune responses are features found in atopic asthmatic airways. Recent studies indicate γ-tocopherol (GT) supplementation can suppress airway inflammation in allergic asthma. We studied the effects of in vitro GT supplementation on receptor-mediated phagocytosis and expression of cell surface molecules associated with innate and adaptive immunity on sputum-derived macrophages. Cells from nonsmoking healthy (n = 6) and mild house dust mite-sensitive allergic asthmatics (n = 6) were treated ex vivo with GT (300 µM) or saline (control). Phagocytosis of opsonized zymosan A bioparticles (Saccharomyces cerevisiae) and expression of surface molecules associated with innate and adaptive immunity were assessed using flow cytometry. GT caused significantly decreased (p < 0.05) internalization of attached zymosan bioparticles and decreased (p < 0.05) macrophage expression of CD206, CD36 and CD86 in allergic asthmatics but not in controls. Overall, GT caused downregulation of both innate and adaptive immune response elements, and atopic status appears to be an important factor.