Antigen presentation by murine dendritic cells is nuclear factor-kappa B dependent both in vitro and in vivo

Transcriptome profiling of tolerogenic dendritic cells conditioned with dual mTOR kinase inhibitor, AZD8055

Dendritic cells (DCs) can initiate and regulate adaptive immunity depending on their maturation status. Many pharmacological and genetic means have been used in the generation of immature/tolerogenic DCs. However, the key factors controlling DCs tolerogenicity remain obscure. In this work, we demonstrated that AZD8055, an ATP-competitive inhibitor of mammalian target of rapamycin (mTOR), could also lead to a tolerogenic DC phenotype from several lines of evidence, such as suppression of T cell proliferation, promoting the generation of Tregs, and inducing allogeneic T cell apoptosis. Further studies using RNA-seq method identified 430, 1172 and 1436 differentially expressed genes (DEGs) between AZD-DCs vs. Control-DCs, LPS-DCs vs. Control-DCs, and AZD-DCs vs. LPS-DCs, respectively. The 5 most differentially expressed transcripts identified by RNA-seq expression profiles were validated by quantitative RT-PCR assays. NF-κB, p38MAPK, the ribosome and PPAR signaling pathways may be involved in the induction of tolerogenic DCs by AZD8055. Functional annotation showed some genes like MGL2, Cadherin-1, 4-1BB, RhoB and Pdpn, were quite different between AZD-DCs and Control-DCs/LPS-DCs, which might be related to the tolerogenic properties of AZD-DCs. Our work provided the potential underlying molecular mechanisms involved in the generation of tolerogenic DCs. Further functional characterization of individual target gene in DC tolerogenicity will help to develop novel therapeutic modalities in circumstances like transplant tolerance induction and autoimmunity.

A versatile supramolecular nanoadjuvant that activates NF-κB for cancer immunotherapy

Although powerful adjuvants hold promise of vaccines for cancer immunotherapy, cumbersome preparation processes, elusive mechanisms and failure to induce T cell responses have largely limited their clinical translation. Due to their ease of synthesis, good biocompatibility and designable bioactivity, peptide derivatives-based supramolecular nanomaterials have attracted increasing interest in improving the immunogenicity of cancer vaccines. Methods: Herein, we synthesized an NF-κB-activating supramolecular nanoadjuvant (3DSNA) that is prepared by pH-triggering self-assembly of a positively charged D-configurational peptide derivative. The immunostimulatory activity of 3DNSA was explored in vitro and in vivo. Results: 3DSNA can strongly absorb the model antigen (ovalbumin, OVA) through electrostatic interaction. Then, 3DSNA promotes ingestion and cross-presentation of OVA, upregulation of costimulatory factors (CD80 and CD86) and secretion of proinflammatory cytokines (IL-6 and IL-12) by dendritic cells (DCs), accompanied by activation of the innate immune response (NF-κB signaling), resulting in long-term antigen-specific memory and effector CD8+ T cells response. When compared with conventional aluminum hydroxide adjuvant and the corresponding L-configurational supramolecular nanoadjuvant (3LSNA), 3DSNA-adjuvanted OVA (3DSNA+OVA) significantly prevents oncogenesis in naïve mice with a complete response rate of 60 %, restrains the tumor growth and prolongs the survival of melanoma-bearing mice. Conclusion: These findings demonstrate that 3DSNA is a promising neo-adjuvant that enables various vaccines to be therapeutic for many important diseases including cancer.

Hyaluronic Acid-Modified and TPCA-1-Loaded Gold Nanocages Alleviate Inflammation

Gold nanocages (AuNCs) are biocompatible and porous nanogold particles that have been widely used in biomedical fields. In this study, hyaluronic acid (HA) and peptide- modified gold nanocages (HA-AuNCs/T/P) loaded with 2-[(aminocarbonyl)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide (TPCA-1) were prepared to investigate their potential for combating inflammation. TPCA-1 was released from AuNCs, intracellularly when HA was hydrolyzed by hyaluronidase. HA-AuNCs/T/P show a much higher intracellular uptake than AuNCs/T/P, and exhibit a much higher efficacy on the suppression of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) than free TPCA-1, suggesting great improvement to the anti-inflammatory efficacy of TPCA-1 through the application of AuNCs. HA-AuNCs/T/P can also reduce the production of reactive oxygen species in inflammatory cells. This study suggests that HA-AuNCs/T/P may be potential agents for anti-inflammatory treatment, and are worthy of further investigation.

Future of Muse Cells

Discovered nearly 10 years ago by Professor Mari Dezawa and her colleagues, Muse cells are entering clinical trials faster than any other stem cell for three reasons. First, Muse cells have multiple fail-safe mechanisms to keep themselves from growing out of control and do not form tumors. In contrast, embryonic stem cells and induced pluripotent stem cells form tumors and must be differentiated before transplantation. Second, Muse cells possess potent anti-immune mechanisms, including human leukocyte antigen G and indoleamine 2,3-dioxygenase that prevent both cellular and humoral immunity. Muse cells engraft even though they do not match HLA antigens with the host. Third, Muse cells are able to determine what kind and how many cells they need to make for tissue repair. While the mechanisms responsible for these traits are not well understood, Muse cells are able to enter severely injured tissues of all kinds and repair them. Study of mechanisms underlying these traits of Muse cells is likely to yield new therapies for cancer prevention, autoimmune diseases, and repair of injured tissues. The future is bright for Muse cells.

Intranasal co-administration of 1,8-cineole with influenza vaccine provide cross-protection against influenza virus infection

BACKGROUND

Vaccination is the most efficient means for protection against influenza. However, the various vaccines have low efficacy to protect against pandemic strains because of antigenic drift and recombination of influenza virus. Adjuvant therapy is one of the attempts to improve influenza vaccine effective cross-protection against influenza virus infection. Our previous study confirmed that 1,8-cineole inhibits the NF-κB, reduces pro-inflammatory cytokines, and relieves the pathological changes of viral pneumonia in mice infected with influenza virus.

HYPOTHESIS/PURPOSE

1,8-cineole, administered via intranasal (i.n.) route, may also have the capacity to be an adjuvant of the influenza vaccine. This study was designed to investigate the potential use of i.n. co-administration of 1,8-cineole, a major component of the Eucalyptus essential oils, with influenza vaccine and whether could provide cross-protection against influenza virus infection in a mouse model.

STUDY DESIGN

I.n. co-administration of 1,8-cineole in two doses (6.25 and 12.5 mg/kg) with influenza vaccine was investigated in a mouse model in order to see whether it could provide cross-protection against influenza virus infection.

METHODS

The mice were intranasally immunized three times at the 0, 7 and 14 day with vaccine containing 0.2 µg hemagglutinin (HA) and/or without 1,8-cineole. Seven days after the 3rd immunization dose, the mice were infected with 50 µl of 15 LD₅₀ (50% mouse lethal dose) influenza virus A/FM/1/47 (H1N1). On day 6 post-infection, 10 mice per group were sacrificed to collect samples, to take the body weight and lung, and detect the viral load, pathological changes in the lungs and antibody, etc. The collected samples included blood serum and nasal lavage fluids. In addition, the survival experiments were carried out  to investigate the survival of mice.

RESULTS

Mice i.n. inoculated with influenza vaccine and 12.5 mg/kg 1,8-cineole increased the production of influenza-specific serum immunoglobulin (Ig) G2a antibodies, stimulated mucosal secretive IgA (s-IgA) responses at the nasal cavity, improved the expression of respiratory tract intraepithelial lymphocytes (IELs) in the upper respiratory tract, and promoted dendritic cell (DC) maturation and the expression of co-stimulatory molecules cluster of differentiation (CD)40, CD80 and CD86 in peripheral blood. Importantly, mice that had received 1,8-cineole-supplemented influenza vaccine showed longer survival time, milder inflammation, less weight loss and mortality rate and lower lung index and viral titers compared to that of mice immunized a non-1,8-cineole-adjuvanted split vaccine. Thus, i.n. immunization with 1,8-cineole-adjuvanted vaccine induces a superior cross-protective immunity against infection with influenza than an inactivated vaccine only.

CONCLUSION

These results suggest that 1,8-cineole (12.5 mg/kg) has a cross-protection against influenza virus, co-administered with inactivated influenza viral antigen in a mouse model.

β2-adrenoceptor signaling reduction in dendritic cells is involved in the inflammatory response in adjuvant-induced arthritic rats

Rheumatoid arthritis (RA) is characterized by inflammation of the synovium, which leads to the progressive destruction of cartilage and bone. Adrenoreceptor (AR) signaling may play an important role in modulating dendritic cell (DC), which may be involved in the pathogenesis of RA. We examined the effect of the β-AR agonist isoprenaline (ISO) on DC function, the impact of the β₂-AR agonist salbutamol on adjuvant-induced arthritic (AA) rats, and changes in β₂-AR signaling in DCs during the course of AA. ISO inhibited the expression of the surface molecules CD86 and MHC-II, inhibited the stimulation of T lymphocyte proliferation by DC and TNF-α secretion, and promoted DC antigen uptake and IL-10 secretion. The effects of ISO on MHC-II expression, DC stimulation of T lymphocyte proliferation, and DC antigen uptake were mediated by β₂-AR. Treatment with salbutamol ameliorated the severity of AA and histopathology of the joints and inhibited proliferation of thymus lymphocytes and FLS in vivo. β₂-AR signaling was weaker in AA rats compared to the control. Elevated GRK2 and decreased β₂-AR expression in DC cytomembranes were observed in AA and may have decreased the anti-inflammatory effect of β₂-AR signaling. Decreased β₂-AR signaling may be relevant to the exacerbation of arthritis inflammation.

Deficiency of IκB Kinase β in Myeloid Cells Reduces Severity of Experimental Autoimmune Encephalomyelitis

In experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), peripherally developed myelin-reactive T lymphocytes stimulate myeloid cells (ie, microglia and infiltrated macrophages) to trigger an inflammatory reaction in the central nervous system, resulting in demyelination and neurodegeneration. IκB kinase β (IKKβ) is a kinase that modulates transcription of inflammatory genes. To investigate the pathogenic role of IKKβ in MS, we developed strains in which IKKβ was conditionally ablated in myeloid cells and established active or passive EAE in these animals. Deficiency of IKKβ in myeloid cells ameliorated EAE symptoms and suppressed neuroinflammation, as shown by decreased infiltration of T lymphocytes and macrophages and reduced inflammatory gene transcription in the spinal cord at the peak or end stage of EAE. Myeloid deficiency of IKKβ also reduced the transcription of Rorc or Il17 genes in T lymphocytes isolated from lymph nodes, spleen, and spinal cord of EAE mice. Moreover, cultured splenocytes isolated from myeloid IKKβ-deficient EAE mice released less IL-17, interferon-γ, and granulocyte-macrophage colony-stimulating factor after treatment with myelin peptide than splenocytes from IKKβ wild-type EAE mice. Thus, deficiency of myeloid IKKβ attenuates the severity of EAE by inhibiting both the neuroinflammatory activity and the activation of encephalitogenic T lymphocytes. These results suggest IKKβ may be a potential target for MS patients, especially when neuroinflammation is the primary problem.

Triptolide-conditioned dendritic cells induce allospecific T-cell regulation and prolong renal graft survival

BACKGROUND

Previous studies show that triptolide (TPT), a diterpenoid isolated from the Chinese herb Tripterygium wilfordii Hook.f, inhibits dendritic cell (DCs) maturation. Whether TPT-conditioned DCs (TPT-DCs) may regulate allospecific immune responses remains unclear. In this study, we investigated the effects of TPT on allostimulatory function and phenotype of rat bone marrow-derived DCs (BMDCs).

METHODS

Brown Norway rats BMDCs were cultured with or without TPT and then stimulated with lipopolysaccharide (LPS). IL-10 in supernatants was quantitatively measured, and the cells were analyzed by flow cytometry and used as stimulators in mixed leukocyte reaction in which naive Lewis rat T lymphocytes were used as responders. The tolerogenic potential of TPT-BMDCs was evaluated in vivo in a rat model of MHC fully mismatched kidney transplantation.

RESULTS

After treatment with TPT, BMDCs remained immature with low expression of CD80 and CD86 in the presence of LPS. At low concentrations of TPT (1 and 2.5 nM), BMDCs produced higher levels of IL-10 than the untreated cells (431 and 205.4 pg/ml, respectively, vs. 122.9 pg/ml, p < .05). T cells cocultured with TPT-BMDCs were hyporesponsive in allogeneic mixed lymphocyte reaction. The CD25+foxp3+Treg cell populations increased from 19.9% to 29.7% in the coculture system. Without immunosuppressive therapy, infusion of TPT-BMDCs in recipients before transplantation prolonged rat kidney allograft survival (18.8 ± 1.30 days).

CONCLUSIONS

Our findings demonstrate that TPT inhibits the maturation and allogenicity of BMDCs and promotes the expansion of CD25+foxp3+ regulatory T cells. It suggests that TPT-DCs are potentially useful for preventing kidney transplant rejection.

Dendritic cell modification as a route to inhibiting corneal graft rejection by the indirect pathway of allorecognition

Dendritic cell (DC) modification is a potential strategy to induce clinical transplantation tolerance. We compared two DC modification strategies to inhibit allogeneic T-cell proliferation. In the first strategy, murine DCs were transduced with a lentiviral vector expressing CTLA4-KDEL, a fusion protein that prevents surface CD80/86 expression by retaining the co-stimulatory molecules within the ER. In the second approach, DCs were transduced to express the tryptophan-catabolising enzyme IDO. CTLA4-KDEL-expressing DCs induced anergy in alloreactive T cells and generated both CD4⁺CD25⁺ and CD4⁺CD25⁻ Treg cells (with direct and indirect donor allospecificity and capacity for linked suppression) both in vitro and in vivo. In contrast, T-cell unresponsiveness induced by IDO⁺ DCs lacked donor specificity. In the absence of any immunosuppressive treatment, i.v. administration of CTLA4-KDEL-expressing DCs resulted in long-term survival of corneal allografts only when the DCs were capable of indirect presentation of alloantigen. This study demonstrates the therapeutic potential of CTLA4-KDEL-expressing DCs in tolerance induction.

Polymorphism M55V in gene encoding small ubiquitin-like modifier 4 (SUMO4) protein associates with susceptibility to type 1 (and type 2) diabetes

BACKGROUND

The association between small ubiquitin-like modifier 4 (SUMO4) gene polymorphism and type 1 diabetes mellitus (T1DM) or type 2 diabetes mellitus (T2DM) has been investigated in several studies. We conducted a meta-analysis to evaluate the association of SUMO4 gene polymorphism with T1DM and T2DM susceptibility.

METHODS

A meta-analysis was performed on the published studies before August 2011. The association of SUMO4 M55V polymorphism with T1DM and T2DM was evaluated. Meta-analysis was performed for genotypes AA versus GG, AA versus AG, AA versus AG + GG and A allele versus G allele in a fixed/random effect model. The combined odds ratio (OR) with 95% confidence interval (95% CI) was calculated to estimate the strength of the association.

RESULTS

Sixteen case-control studies including 9190 cases and 10 456 healthy controls were included. T1DM patients were divided into Asian and Caucasian subgroup. We detected a significant association of SUMO4 M55V polymorphism with T1DM in Asian population (A versus G: OR = 0.79, 95%CI = 0.72-0.86, p = 0.000) and a significant association of SUMO4 M55V polymorphism with T1DM in Caucasian population (A versus G: OR = 0.84, 95%CI = 0.73-0.97, p = 0.007). Included T2DM patients were all Asian. Meanwhile, a significant association of SUMO4 M55V polymorphism with T2DM was also found (A versus G: OR = 0.86, 95%CI = 0.79-0.94, p = 0.001).

CONCLUSIONS

Our study demonstrates significant associations of SUMO4 M55V polymorphism with T1DM in Asian and Caucasian population and with T2DM in Asian population.

Activation of NF-κB in CD8+ dendritic cells Ex Vivo by the γ134.5 null mutant correlates with immunity against herpes simplex virus 1

The γ(1)34.5 protein of herpes simplex viruses (HSV) is essential for virulence. Accordingly, an HSV mutant lacking γ(1)34.5 is attenuated in vivo. Despite its vaccine potential, the mechanism by which the γ(1)34.5 null mutant triggers protective immunity is unknown. In this report we show that vaccination with the γ(1)34.5 null mutant protects against lethal challenge from wild-type virus via IκB kinase in dendritic cells (DCs), which sense virus-associated molecular patterns. Unlike mock-treated DCs, DCs primed with the γ(1)34.5 null mutant ex vivo mediate resistance to wild-type HSV after adoptive transfer into naïve mice. Furthermore, the γ(1)34.5 null mutant activates IκB kinase, which facilitates p65/RelA phosphorylation and nuclear translocation, resulting in DC maturation. While unable to produce infectious virus in DCs, this mutant virus expresses early and late genes. In its abortive infection, the γ(1)34.5 null mutant induces protective immunity more effectively in CD8(+) DCs than in CD8(-) DCs. This is mirrored by a higher level of interleukin-6 (IL-6) and IL-12 secretion by CD8(+) DCs than CD8(-) DCs. Remarkably, inhibition of p65/RelA phosphorylation or nuclear translocation in CD8(+) DCs disrupts protective immunity. These results suggest that engagement of the γ(1)34.5 null mutant with CD8(+) DCs elicits innate immunity to activate NF-κB, which translates into protective immunity.

Implications of the innate immune response to adenovirus and adenoviral vectors

Adenovirus (AdV) is a common cause of respiratory illness in both children and adults. Respiratory symptoms can range from those of the common cold to severe pneumonia. Infection can also cause significant disease in the immunocompromised and among immunocompetent subjects in close quarters. Fortunately, infection with AdV in the normal host is generally mild. This is one reason why its initial use as a gene-therapy vector appeared to be so promising. Unfortunately, both innate and adaptive responses to the virus have limited the development of AdV vectors as a tool of gene therapy by increasing toxicity and limiting duration of transgene expression. This article will focus on the innate immune response to infection with wild-type AdV and exposure to AdV gene-therapy vectors. As much of the known information relates to the pulmonary inflammatory response, this organ system will be emphasized. This article will also discuss how that understanding has led to the creation of new vectors for use in gene therapy.

Vaccination with Human Induced Pluripotent Stem Cells Creates an Antigen-Specific Immune Response Against HIV-1 gp160

Induced pluripotent stem cells (iPSCs) are artificially derived from somatic cells that have been transduced with defined reprogramming factors. A previous report has indicated the possibility of using iPSCs as an immune stimulator to generate antigen-specific immunity. In our current study, we have investigated whether human iPSCs (hiPSCs) have the ability to enhance specific immune response against a human immunodeficiency virus type 1 (HIV-1) antigen in a xenogenic mouse model. Our results show that BALB/c mice immunized with hiPSCs transduced with an adenoviral vector encoding HIV-1 gp160 exhibited prominent antigen-specific cellular immune responses. We further found that pre-treatment of hiPSCs with ionizing radiation promotes the secretion of pro-inflammatory cytokines such as interleukin-1 alpha (IL-1α), IL-12, and IL-18. These cytokines might promote the activation of antigen-presenting cells and the effective induction of cellular immunity. Our present findings thus demonstrate that a hiPSCs-based vaccine has the potential to generate cellular immunity against viral antigens such as HIV-1 gp160 in a xenogenic condition.

Induction of pathogenic cytotoxic T lymphocyte tolerance by dendritic cells: a novel therapeutic target

IMPORTANCE OF THE FIELD

Dendritic cells (DCs) have an important role, both direct and indirect, in controlling the expansion and function of T cells. Of the different subsets of T cells, cytotoxic T lymphocytes (CTLs/CD8(+) T cells) have been implicated in the pathogenesis and development of many diseases, including various forms of autoimmunity and transplant rejection. It may therefore be of therapeutic benefit to control the function of CTL in order to modulate disease processes and to ameliorate disease symptoms. Currently, pharmacological approaches have been employed to either directly or indirectly modulate the function of T cells. However, these treatment strategies have many limitations. Many experimental data have suggested that it is possible to alter CTL activity through manipulation of DC.

AREAS COVERED IN THIS REVIEW

Novel strategies that condition DCs to influence disease outcome through manipulation of CTL activity, both directly and indirectly. This includes the modulation of co-stimulation, negative co-stimulation, as well as manipulation of the cytokine milieu during CTL generation. Furthermore, DCs may also impact CTL activity through effects on effector and regulatory cells, along with manipulation of bioenergetic regulation, apoptotic-cell mediated tolerance and through the generation of exosomes. The implications of related interventions in the clinical arena are in turn considered.

WHAT THE READER WILL GAIN

Insight into such indirect methods of controlling CTL activity allows for an understanding of how disease-specific T cells may be regulated, while also sparing other aspects of adaptive immunity for normal physiological function. Such an approach towards the treatment of disease represents an innovative therapeutic target in the clinical arena.

TAKE HOME MESSAGE

There are numerous innovative methods for using DCs to control CTL responses. Manipulation of this interaction is thus an attractive avenue for the treatment of disease, particularly those of immune dysregulation, such as seen in autoimmunity and transplantation. With the number of studies moving into clinical stages constantly increasing, further advances and successes in this area are inevitable.

Salsalate may have broad utility in the prevention and treatment of vascular disorders and the metabolic syndrome

In the high proportion of vascular disorders associated with excessive oxidative stress and production of pro-inflammatory cytokines, activation of NF-kappaB plays a key pathogenic role. Thus, there is considerable evidence that NF-kappaB is a mediator of atherogenesis, plaque destabilization, ischemia-reperfusion damage, cardiac remodeling, atrial fibrillation, and aneurysm formation and rupture; some studies suggest that it may also play a role in the microvascular complications of diabetes. I kappaB kinase-beta (IKK beta) is the upstream kinase that appears to be primarily responsible for NF-kappaB activation in these disorders; moreover, chronic IKK beta activation plays a prominent role in induction of insulin resistance in the metabolic syndrome. Salicylate inhibits IKK beta in concentrations that are achievable with dose schedules traditionally used in treating rheumatoid arthritis (3-4.5 g daily); indeed, this is likely to be the mechanism responsible for salicylate's utility in this disorder. Salicylate, unlike aspirin, is only a very weak, reversible inhibitor of cyclooxygenase in clinical doses, and thus is not associated with the potentially dangerous side effects seen with NSAIDs; fully reversible ototoxicity, the dose-limiting side effect in salicylate therapy, can be avoided in most patients by dosage adjustment. Hence, it is proposed that salicylate may have practical utility in the prevention or management of a wide range of vascular disorders as well as of metabolic syndrome and diabetes; its efficacy in these regards would likely be complemented by effective antioxidant measures, which would lessen the stimulus to NF-kappaB activation while providing benefits independent of NF-kappaB activity. Salsalate, consisting of two salicylate molecules united by an ester bond, is a venerable drug that may be the best tolerated delivery vehicle for salicylate. Appropriate rodent studies should pave the way for clinical trials with salsalate in patients at vascular risk.

Characterization of nickel-decorated PLGA particles anchored with a his-tagged polycation

The pharmacological impact of oligodeoxynucleotides (ODN) as transcription factors decoys (anti-sense) depends on the efficiency of cellular uptake. In this study, we sought to generate nickel-decorated particles to facilitate the entry of ODN into dendritic cells (DCs), the primary instigators of immune responses. Nickel ions were incorporated into the matrix of poly(D,L-lactide-co-glycolide) (PLGA) particles using the metal chelating lipid DOGS-NTA-Ni. Submicrometer-sized PLGA particles containing nickel ions (PLGA-Ni) were formed using a double-emulsion solvent evaporation method. Infrared spectroscopy provided chemical proofs of nickel incorporation into the PLGA matrix. Binding of the polycation O10H6 raised the surface potential of PLGA-Ni from -17 mV to +13 mV. This change was partially reserved by the presence of free imidazole, suggesting the binding was mediated by nickel-histidine coordination. When compared to PLGA particles without nickel, ODN bound to O10H6-coated PLGA-Ni particles exhibited enhanced capacity to accumulate in DCs cultured in vitro. DCs exhibited cellular stress after exposure to PLGA-Ni complexed with O10H6 and DNA, but this effect can be prevented by serum and was reversed overnight. These data suggest PLGA-Ni should be further explored as a nucleic acid carrier in the context of anti-sense gene down-regulation.

Increased IkappaB alpha expression is essential for the tolerogenic property of TGF-beta-exposed APCs

IkappaB alpha is an inhibitor of the transcriptional factor NF-kappaB, and it is an essential component of the signaling pathways that lead to expression of inflammatory molecules. These include cytokines and costimulatory molecules associated with antigen presentation in an inflammatory immune response. In this study, we report that antigen-presenting cells exposed to TGF-beta induce peripheral tolerance by increasing IkappaB alpha expression. Exposure of antigen presenting cells (APCs) to TGF-beta is known to impair their ability to secrete IL-12, and such impairment correlated with reduced NF-kappaB activity as indicated by significantly reduced nuclear levels of p50, an essential subunit of NF-kappaB for IL-12 transcription. Blockade of increased nuclear IkappaB alpha in APCs by expression of small interfering RNA molecules (siRNAs) targeting IkappaB alpha transcripts prevented IL-12 impairment and the decline in nuclear p50 levels. Furthermore, such IkappaB alpha blockade also interfered with the tolerogenic property of TGF-beta-exposed APCs. However, increased expression of IkappaB alpha in APCs, independent of TGF-beta exposure, reduced nuclear p50 levels and permitted tolerance induction by APCs. Thus, our findings attribute a direct and significant role to IkappaB alpha in the tolerogenic potential of APCs. Increased IkappaB alpha expression in APCs may therefore offer a therapeutic approach to achieve antigen-specific immunomodulation.

Polymeric microspheres as stabilizing anchors for oligonucleotide delivery to dendritic cells

The aim of this study is to evaluate a novel microspheric vector for delivery of oligonucleotides (ODN) into dendritic cells (DC). A requirement of decoy-based modulation of transcriptional activities in DC is that the ODN would have to accumulate inside the cell. Using an ex vivo DC culture model, we demonstrate that anionic microspheres (MS) coated with an ornithine/histadine-based cationic peptide (O10H6) is an effective carrier of short ODN. This method does not disrupt the colloidal nature of the microspheric particles. The MS provide stabilizing effect on DNA and O10H6 complexation. Accumulation of ODN in DC is greatly enhanced with the surface modified MS. Taken together, these data demonstrate that the self assembly system of MS(O10H6) is an effective delivery vehicle for DNA-based modulation of DC functions.

Innate Immune Response to Adenovirus

Adenovirus is a common infectious pathogen in both children and adults. It is a significant cause of morbidity in immunocompetent people living in crowded living conditions and of mortality in immunocompromised hosts. It has more recently become a popular vehicle for gene therapy applications. The host response to wild-type infection and gene therapy vector exposure involves both the innate and adaptive immune systems. The initial innate immune response is associated with the severe acute manifestations of adenovirus infection and also plays a significant role in acute toxicity owing to adenovirus vector exposure. This review discusses the innate immune response primarily during wild-type adenovirus infection because this serves as the basis for understanding the response during both natural infection and exposure to adenovirus vectors.

The role of the mitochondrion in trauma and shock

The mitochondrion of the eukaryotic cell is well known as a "power plant" whose energy is made available via the high-energy phosphate bonds of ATP. This indispensable and superbly adapted organelle appears to have originated as an endosymbiotic bacterium rather than as a eukaryotic creation per se. However, under the dangerous conditions of trauma and shock, the mitochondrion can become destabilized and harm its host cell in a variety of ways. These contrary traits may be, in part, vestiges from the bacterial origins of mitochondria. The mitochondrion can respond to the stress of trauma and shock by opening pores that leak contents into the host cell's cytoplasm, an event that can trigger programmed cell death or necrosis. In addition, the enormous oxygen consumption by mitochondria presents a two-edged sword in that a deranged mitochondrion can produce reactive oxygen species that damage genes and gene products, inflicting considerable harm to the mitochondrion and its host cell. However, although trauma and shock can cause the mitochondrion to wreak havoc in many ways, an adjuvant intervention with exogenous ATP-MgCl2 after trauma and shock appears useful for reducing cell and organ damage under those conditions.

A new NF-κB inhibitor attenuates a TH 1 type immune response in a murine model

Nuclear factor kappa B (NF-kappaB) plays a wide variety of pathophysiological roles and modulation of its pathway can be a good novel drug target. Here, we found that our recently synthesized NF-kappaB inhibitor attenuated an ovalbumin-specific delayed-type hypersensitivity response in vivo and suppressed production of IL-12 by dendritic cells and TH1 cytokines by T cells in vitro. These findings suggest that the activation of NF-kappaB mounts TH1 type immune responses, and that this new NF-kappaB inhibitor has a therapeutic potential in this context.

Attenuation of murine collagen-induced arthritis by a novel, potent, selective small molecule inhibitor of IkappaB Kinase 2, TPCA-1 (2-[(aminocarbonyl)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide), occurs via reduction of proinflammatory cytokines and antigen-induced T cell Proliferation

Demonstration that IkappaB kinase 2 (IKK-2) plays a pivotal role in the nuclear factor-kappaB-regulated production of proinflammatory molecules by stimuli such as tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 suggests that inhibition of IKK-2 may be beneficial in the treatment of rheumatoid arthritis. In the present study, we demonstrate that a novel, potent (IC(50) = 17.9 nM), and selective inhibitor of human IKK-2, 2-[(aminocarbonyl)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide (TPCA-1), inhibits lipopolysaccharide-induced human monocyte production of TNF-alpha, IL-6, and IL-8 with an IC(50) = 170 to 320 nM. Prophylactic administration of TPCA-1 at 3, 10, or 20 mg/kg, i.p., b.i.d., resulted in a dose-dependent reduction in the severity of murine collagen-induced arthritis (CIA). The significantly reduced disease severity and delay of disease onset resulting from administration of TPCA-1 at 10 mg/kg, i.p., b.i.d. were comparable to the effects of the antirheumatic drug, etanercept, when administered prophylactically at 4 mg/kg, i.p., every other day. Nuclear localization of p65, as well as levels of IL-1beta, IL-6, TNF-alpha, and interferon-gamma, were significantly reduced in the paw tissue of TPCA-1- and etanercept-treated mice. In addition, administration of TPCA-1 in vivo resulted in significantly decreased collagen-induced T cell proliferation ex vivo. Therapeutic administration of TPCA-1 at 20 mg/kg, but not at 3 or 10 mg/kg, i.p., b.i.d., significantly reduced the severity of CIA, as did etanercept administration at 12.5 mg/kg, i.p., every other day. These results suggest that reduction of proinflammatory mediators and inhibition of antigen-induced T cell proliferation are mechanisms underlying the attenuation of CIA by the IKK-2 inhibitor, TPCA-1.

T Cells Signaled by NF-κB−Dendritic Cells Are Sensitized Not Anergic to Subsequent Activation

Paradoxically, while peripheral self-tolerance exists for constitutively presented somatic self Ag, self-peptide recognized in the context of MHC class II has been shown to sensitize T cells for subsequent activation. We have shown that MHC class II(+)CD86(+)CD40(-) DC, which can be generated from bone marrow in the presence of an NF-kappa B inhibitor, and which constitutively populate peripheral tissues and lymphoid organs in naive animals, can induce Ag-specific tolerance. In this study, we show that CD40(-) human monocyte-derived dendritic cells (DC), generated in the presence of an NF-kappa B inhibitor, signal phosphorylation of TCR zeta, but little proliferation or IFN-gamma in vitro. Proliferation is arrested in the G(1)/G(0) phase of the cell cycle. Surprisingly, responding T cells are neither anergic nor regulatory, but are sensitized for subsequent IFN-gamma production. The data indicate that signaling through NF-kappa B determines the capacity of DC to stimulate T cell proliferation. Functionally, NF-kappa B(-)CD40(-)class II(+) DC may either tolerize or sensitize T cells. Thus, while CD40(-) DC appear to "prime" or prepare T cells, the data imply that signals derived from other cells drive the generation either of Ag-specific regulatory or effector cells in vivo.