Preventing tissue injury using siRNA

RNA interference (RNAi) is a process through which double-stranded RNA induces the activation of endogenous cellular pathways of RNA degradation, resulting in selective and potent silencing of genes that have homology to the double strand. Much of the excitement surrounding small interfering RNA (siRNA)-mediated therapeutics arises from the fact that this approach overcomes many of the shortcomings previously experienced with alternative approaches to selective blocking that use antibodies, antisense oligonucleotides or pharmacological inhibitors. Induction of RNAi through administration of siRNA has been successfully applied to the treatment of hepatitis, viral infections, and cancer. Increased success in addressing issues of siRNA delivery and efficiency will permit this approach to evolve as a new paradigm in clinical therapeutics. In this chapter, we present applications of RNAi in tissue injury, and the possibilities of using this highly promising approach in the context of transplantation.

Non-expanded adipose stromal vascular fraction cell therapy for multiple sclerosis

The stromal vascular fraction (SVF) of adipose tissue is known to contain mesenchymal stem cells (MSC), T regulatory cells, endothelial precursor cells, preadipocytes, as well as anti-inflammatory M2 macrophages. Safety of autologous adipose tissue implantation is supported by extensive use of this procedure in cosmetic surgery, as well as by ongoing studies using in vitro expanded adipose derived MSC. Equine and canine studies demonstrating anti-inflammatory and regenerative effects of non-expanded SVF cells have yielded promising results. Although non-expanded SVF cells have been used successfully in accelerating healing of Crohn's fistulas, to our knowledge clinical use of these cells for systemic immune modulation has not been reported. In this communication we discuss the rationale for use of autologous SVF in treatment of multiple sclerosis and describe our experiences with three patients. Based on this rationale and initial experiences, we propose controlled trials of autologous SVF in various inflammatory conditions.

Human embryonic stem cells hemangioblast express HLA-antigens

Background

It has been suggested that the initial differentiation of endothelial and hematopoietic cells during embryogenesis occurs from a common progenitor, called hemangioblast (hB). We hypothesized that these cells with dual hematopoietic/endothelial potential could be used in future regenerative medicine.

Methods

We used the two-step differentiation technology to generate bipotential blast cells from human embryonic stem cells (hES). This involved short differentiation in our in vitro EB system followed by differentiation in semisolid culture medium supplemented with mixture of cytokines.

Results

The occurrence of blast-colony-forming cells (BL-CFC) during EB differentiation (day 0–6) was transient and peaked on day 3. The emergence of this event was associated with expression of mesoderm gene T, and inversely correlated with expression of endoderm gene FoxA2. Similarly, the highest BL-CFC number was associated with increase in expression of early hematopoietic/endothelial genes: CD34, CD31 and KDR. The derived colonies were composed of 30–50 blast cells on day 6 in culture. These cells had homogenous appearance in Wright-Giemsa stain, but to a different extent expressed markers of immature hematopoietic and endothelial cells (CD31, CD34, VE-cadherin, Flt-1) and mature differentiated cells (CD45, CD33, CD146). We found that some of them expressed fetal and embryonic globin genes. Interestingly, these cells expressed also HLA class I molecules, however at very low levels compared to endothelial and hematopoietic cells. The blast cells could be successfully differentiated to hematopoietic cells in a CFU assay. In these conditions, blast cells formed CFU-M colonies (63.4 ± 0.8%) containing macrophages, BFU-E colonies (19.5 ± 3.5%) containing nucleated red blood cells, and CFU-EM colonies (17.1 ± 2.7%) composed of macrophages and nucleated erythrocytes. Cells of CFU-EM and BFU-E colonies expressed both ε – and γ- globin genes, but not adult-type γ-globin. When in endothelial cell culture conditions, blast cells differentiated to endothelial cells which had the ability to take up Dil-Ac-LDL and to form complex vascular networks in Matrigel.

Conclusion

1) Hematoendothelial precursors exist transiently in early embryonic development and form single cell-derived colonies; 2) their differentiation can be tracked by the use of chosen molecular markers; 3) blast colonies consist of cells having properties of endothelial and hematopoietic precursors, however the issue of their ability to maintain dual properties over time needs to be further explored; 4) blast cells can potentially be used in regenerative medicine due to their low expression of HLA molecules.

Inhibition of intracranial glioma growth by endometrial regenerative cells

Animal studies have demonstrated that selective tropism of mesenchymal stem cells (MSC) for glioma may be used as a means of selective delivery of cytotoxic payloads. Endometrial Regenerative Cells (ERC) are a population of mesenchymal-like cells which possesse pluripotent differentiation capacity and is characterized by unique surface markers and growth factor production. In this study we sought to determine whether unmanipulated ERC would alter the growth of glioma using the aggressive C6/LacZ7 (C6) into Sprague Dawley rat model. ERC administration by intravenous (i.v.) or intratumoral (i.t.) showed significant inhibition of glioma: volume reduction of 49% after i.v. treatment (p < 0.05), and about 46% i.t. treatment (p < 0.05). Tumor reduction was associated with inhibition of angiogenesis and reduced numbers of CD133 positive cells in the incranial tumor. Despite the angiogenic potential of ERC in the hindlimb ischemia model, these data support a paradoxical tumor inhibitory activity of ERC. Further studies are needed to determine the qualitative differences between physiological angiogenesis, which seems to be supported by ERC and tumor angiogenesis which appeared to be inhibited.

Feasibility investigation of allogeneic endometrial regenerative cells

Endometrial Regenerative Cells (ERC) are a population of mesenchymal-like stem cells having pluripotent differentiation activity and ability to induce neoangiogenesis. In vitro and animal studies suggest ERC are immune privileged and in certain situations actively suppress ongoing immune responses. In this paper we describe the production of clinical grade ERC and initial safety experiences in 4 patients with multiple sclerosis treated intravenously and intrathecally. The case with the longest follow up, of more than one year, revealed no immunological reactions or treatment associated adverse effects. These preliminary data suggest feasibility of clinical ERC administration and support further studies with this novel stem cell type.

NK cells induce apoptosis in tubular epithelial cells and contribute to renal ischemia-reperfusion injury

Renal ischemia-reperfusion injury (IRI) can result in acute renal failure with mortality rates of 50% in severe cases. NK cells are important participants in early-stage innate immune responses. However, their role in renal tubular epithelial cell (TEC) injury in IRI is currently unknown. Our data indicate that NK cells can kill syngeneic TEC in vitro. Apoptotic death of TEC in vitro is associated with TEC expression of the NK cell ligand Rae-1, as well as NKG2D on NK cells. In vivo following IRI, there was increased expression of Rae-1 on TEC. FACS analyses of kidney cell preparations indicated a quantitative increase in NKG2D-bearing NK cells within the kidney following IRI. NK cell depletion in wild-type C57BL/6 mice was protective, while adoptive transfer of NK cells worsened injury in NK, T, and B cell-null Rag2(-/-)gamma(c)(-/-) mice with IRI. NK cell-mediated kidney injury was perforin (PFN)-dependent as PFN(-/-) NK cells had minimal capacity to kill TEC in vitro compared with NK cells from wild-type, FasL-deficient (gld), or IFN-gamma(-/-) mice. Taken together, these results demonstrate for the first time that NK cells can directly kill TEC and that NK cells contribute substantially to kidney IRI. NK cell killing may represent an important underrecognized mechanism of kidney injury in diverse forms of inflammation, including transplantation.

Novel vaccination for allergy through gene silencing of CD40 using small interfering RNA

Small interfering RNA (siRNA) is a potent means of inducing gene-specific silencing. Gene silencing strategies using siRNA have demonstrated therapeutic benefits in animal models of various diseases, and are currently in clinical trials. However, the utility of gene silencing as a treatment for allergic diseases has not yet been reported. In this study, we report a novel therapy for allergy through gene silencing of CD40, a critical costimulatory molecule and a key factor in allergic immune responses. Silencing CD40 resulted in generation of immunoregulatory dendritic cells (DCs). Administration of CD40 siRNA remarkably reduced nasal allergic symptoms and local eosinophil accumulation in the OVA-induced allergic mice. The OVA-specific T cell response was inhibited after the CD40 siRNA treatment. Additionally, anti-OVA specific IgE and production of IL-4 and IL-5 of T cells stimulated by OVA were significantly decreased in CD40 siRNA-treated mice. Furthermore, we demonstrated that the therapeutic effects by CD40 siRNA were associated with impaired Ag-presenting functions of DCs and B cells, and generation of regulatory T cells. The present study highlights a therapeutic potential of siRNA-based treatment for allergic diseases.

Gene silencing of complement C5a receptor using siRNA for preventing ischemia/reperfusion injury

Ischemia/reperfusion (I/R) injury in organ transplantation significantly contributes to graft failure and is untreatable using current approaches. I/R injury is associated with activation of the complement system, leading to the release of anaphylatoxins, such as C5a, and the formation of the membrane attack complex. Here, we report a novel therapy for kidney I/R injury through silencing of the C5a receptor (C5aR) gene using siRNA. Mice were injected with 50 microg of C5aR siRNA 2 days before induction of ischemia. Renal ischemia was then induced through clamping of the renal vein and artery of the left kidney for 25 minutes. The therapeutic effects of siRNA on I/R were evaluated by assessment of renal function, histopathology, and inflammatory cytokines. siRNA targeting C5aR efficiently inhibited C5aR gene expression both in vitro and in vivo. Administering C5aR siRNA to mice preserved renal function from I/R injury, as evidenced by reduced levels of serum creatinine and blood urea nitrogen in the treated groups. Inhibition of C5aR also diminished in vivo production of the pro-inflammatory cytokine tumor necrosis factor-alpha and chemokines MIP-2 and KC, resulting in the reduction of neutrophils influx and cell necrosis in renal tissues. This study demonstrates that siRNA administration represents a novel approach to preventing renal I/R injury and may be used in a variety of clinical settings, including transplantation and acute tubular necrosis.

Exosomes as a tumor immune escape mechanism: possible therapeutic implications

Advances in cancer therapy have been substantial in terms of molecular understanding of disease mechanisms, however these advances have not translated into increased survival in the majority of cancer types. One unsolved problem in current cancer therapeutics is the substantial immune suppression seen in patients. Conventionally, investigations in this area have focused on antigen-nonspecific immune suppressive molecules such as cytokines and T cell apoptosis inducing molecules such as Fas ligand. More recently, studies have demonstrated nanovesicle particles termed exosomes are involved not only in stimulation but also inhibition of immunity in physiological conditions. Interestingly, exosomes secreted by cancer cells have been demonstrated to express tumor antigens, as well as immune suppressive molecules such as PD-1L and FasL. Concentrations of exosomes from plasma of cancer patients have been associated with spontaneous T cell apoptosis, which is associated in some situations with shortened survival. In this paper we place the "exosome-immune suppression" concept in perspective of other tumor immune evasion mechanisms. We conclude by discussing a novel therapeutic approach to cancer immune suppression by extracorporeal removal of exosomes using hollow fiber filtration technology

Generation of therapeutic dendritic cells and regulatory T cells for preventing allogeneic cardiac graft rejection

Tolerogenic dendritic cells (Tol-DCs) and regulatory T cells (Treg) are key factors in the induction and maintenance of transplantation tolerance. We previously demonstrated that ex vivo-isolated Tol-DCs promote Treg generation, and vice versa, in an in vitro co-culture system. Here we demonstrate the occurrence of such an immune regulatory feedback loop in vivo. Tol-DC generated in vitro by treatment with LF 15-0195 exhibited features of immature DC and express low levels of MHC class II, CD86 and CD40. These Tol-DCs were capable of augmenting CD4(+)CD25(+)CTLA4(+) and FoxP3(+) Treg cell numbers and activity in cardiac allograft recipients. On the other hand, Tol-DCs possessed an ability to generate Treg cells in vitro. The adoptive transfer of these in vitro-generated Treg cells resulted in an increase of Tol-DC in vivo, suggesting that an immune regulatory feedback loop, between Tol-DC and Treg, exists in vivo. Furthermore, the administration of in vitro-generated Tol-DCs or Treg cells prevented rejection of allografts. Co-administration of Tol-DC and Treg synergized efficacy of promoting allograft survival heart transplantation. The present study highlights the therapeutic potential of preventing allograft rejection using in vitro-generated Tol-DCs and Treg.

Selective apoptosis of breast cancer cells by siRNA targeting of BORIS

Brother of the regulator of imprinted sites (BORIS) is an epigenetically acting transcription factor which represses the tumor inhibitor functions of the tumor suppressor protein CTCF. BORIS expression has not been documented in adult females, making it an exciting molecular target for drug development in breast cancer. Previously, we demonstrated that vaccination of mice with zing-finger (ZF)-deleted non-functional BORIS results in regression of breast cancer and generation of potent anti-tumor immune responses. RNAi induction can be used as an alternative approach for selective tumor cell killing. Short interfering RNA (siRNA) molecules targeting BORIS were generated and their efficacy was tested in MDA-MB-231 breast cancer and non-malignant epithelial cell lines. Treatment with BORIS-specific siRNA, but not control siRNA led to a concentration-dependent reduction in BORIS expression and proportional apoptotic death of the cancer but not control cells. To our knowledge this is first report demonstrating a critical role of BORIS in maintaining tumor cell viability.

Antigen-specific therapy of rheumatoid arthritis

BACKGROUND

Immunotherapy offers the promise of antigen-specific suppression of pathological immune responses in conditions such as autoimmunity and organ transplantation. Substantial advances have been made in recent years in terms of understanding basic immunological mechanisms of autoreactivity, as well as clinically implementing immune-based therapies that are antigen nonspecific.

OBJECTIVE

To provide an integrated overview of the current state of the art in terms of antigen-specific tolerance induction, as well as to predict future directions for the field.

METHODS

Examples of successes and failures of antigen-specific immunotherapy were sought. Particular attention was paid to the well-established collagen II-induced model of arthritis.

RESULTS/CONCLUSIONS

Previous failures of antigen-specific immunotherapy were associated with lack of identification of clinically relevant antigens, as well as inappropriate tolerogenic methodologies. The advances in proteomics combined with novel gene-specific immune modulatory techniques place today's translational researchers in a unique position to tackle the problem of antigen-specific immunotherapeutic protocols.

Immune modulation and tolerance induction by RelB-silenced dendritic cells through RNA interference

Dendritic cells (DC), the most potent APCs, can initiate the immune response or help induce immune tolerance, depending upon their level of maturation. DC maturation is associated with activation of the NF-kappaB pathway, and the primary NF-kappaB protein involved in DC maturation is RelB, which coordinates RelA/p50-mediated DC differentiation. In this study, we show that silencing RelB using small interfering RNA results in arrest of DC maturation with reduced expression of the MHC class II, CD80, and CD86. Functionally, RelB-silenced DC inhibited MLR, and inhibitory effects on alloreactive immune responses were in an Ag-specific fashion. RelB-silenced DC also displayed strong in vivo immune regulation. An inhibited Ag-specific response was seen after immunization with keyhole limpet hemocyanin-pulsed and RelB-silenced DC, due to the expansion of T regulatory cells. Administration of donor-derived RelB-silenced DC significantly prevented allograft rejection in murine heart transplantation. This study demonstrates for the first time that transplant tolerance can be induced by means of RNA interference using in vitro-generated tolerogenic DC.

A novel in vivo siRNA delivery technology for dendritic cell-specific gene silencing and immune modulation (89.5)

Silencing immune molecules, such as the costimulatory molecule CD40, using siRNA was shown to have therapeutic potential and promise in immune modulation. However, a major barrier to the clinical application of siRNA is the current lack of an effective and cell-specific delivery system. Herein, we present a new method of selectively delivering siRNA to DC in vivo using stealth immunoliposomes (SILs). CD40 siRNA-containing SILs were generated using 4 types of lipids and decorated with surface-bound, DC-specific mAbs. DC-specific binding capacity of SILs was demonstrated by fluorescence microscopy and flow cytometry. Upon treatment with CD40 siRNA-SILs, DC expression of CD40 was successfully suppressed in vitro. Administration of CD40 siRNA-SILs resulted in DC-specific tissue targeting, as evidenced by increased uptake of fluorescence-tagged siRNA. Additionally, DC from mice treated with CD40 siRNA-SILs exhibited CD40-specific gene silencing in vivo. Tolerogenic properties of DC treated with CD40 siRNA-SILs were determined by inhibition of allogeneic T cell proliferation in MLR. Furthermore, a strong in vivo immune modulation was observed in mice treated with CD40 siRNA-SILs. In conclusion, this is the first demonstration of DC-specific siRNA delivery and gene silencing in vivo, which highlights the potential of DC-mediated immune modulation and the feasibility of siRNA-based clinical therapy.

A Novel Immune-Based Cancer Therapy Using Gene-Silenced Dendritic Cells (48.8)

Hyporesponsiveness is a major hallmark in dendritic cells (DC)-mediated anticancer immunotherapy. Indoleamine 2, 3-dioxygenase (IDO), an immunosuppressive molecule expressed by DC, is a critical factor mediating hyporesponsiveness to cancer immune therapy. We hypothesized that silencing of IDO in DC using siRNA would enhance anticancer therapy. In this study, DC were cultured in vitro, exposed to melanoma B16 lysate, silenced with IDO siRNA, and injected into C57/BL6 mice. Mice were then challenged with B16 tumor cells. The anticancer effects of IDO-silenced DC therapy, compared with non-silenced, conventional control DC vaccine, were evidenced by

postponed melanoma tumor onset time, anddecreased tumor size.

In addition, after immunization with IDO-silenced DC, the number of CD8+ T cells was significantly increased while CD4+ and CD8+ T cell apoptosis in draining lymph nodes was remarkably reduced. Furthermore, immunization with IDO-silenced DC enhanced tumor antigen-specific T cell proliferation and CTL activity, and decreased numbers of CD4+CD25+FoxP3+ regulatory T cells (Treg). In conclusion, this study is the first to demonstrate a novel anti-tumor vaccine by silencing an immunosuppressive gene (IDO) in DC, which enhanced anti-tumor immunity, reduced T cell apoptosis and Treg cell formation, and prevented tumor growth. IDO-silenced DC have clinical potential as an immune-based therapy.

Antitumor Effect of Large Doses IL-2-Activated HLA Haploidentical Peripheral Blood Stem Cells on Refractory Metastatic Solid Tumor Treatment

OBJECTIVE

The traditional immunotherapy for patients with refractory metastatic solid tumors is limited because tumors induce immunosuppression. New treatment is, therefore, needed. The aim of this study was to evaluate the clinical efficacy of infusion of high-dose interleukin (IL)-2-activated allogeneic haploidentical peripheral blood stem cells (haplo-PBSCTs) on patients with an advanced stage of refractory solid tumors.

METHODS

This study involved 11 patients with refractory metastatic tumors and haploidentical relatives as donors for haplo-PBSCs. The therapeutic outcome of the IL-2-activated haplo-PBSC infusion and patients' cytokine levels were evaluated. The cytotoxicity of IL-2-activated haplo-PBSCs for tumor cells was determined using in vitro cytotoxicity assays.

RESULTS

A range from 2.5 to 5.6 x 10(10) of activated haplo-PBSCs were harvested after exposure to rhIL-2, along with a significant increase in the proportion of natural killer (NK) cells and activated lymphocytes (CD69+ and CD25+), and enhanced cytotoxicity of haplo-PBSCs for several tumor cell lines. Following treatment, 1 (1/11) patient achieved a partial response (PR), 1 (1/11) achieved a mild response (MR), 6 (6/11) achieved stable disease (SD), and 3 (3/11) achieved progressive disease (PD). For all of the 11 patients, the median progression-free survival (PFS) was 5 months (3-14 months). We also observed the phenomenon of Th2 shifted to Th1, which played a crucial role in cancer immunotherapy.

CONCLUSIONS

The adoptive transfusion of IL-2-activated haplo-PBSCs has potent antitumor effects both in vitro and in vivo. This finding suggests that IL-2-activated haplo-PBSCs may serve as an alternative therapy for advanced-stage solid tumors, especially for those patients who are refractory or ineligible for chemo- or radiotherapy.

Immune modulation through silencing CD80 and CD86 in dendritic cells using siRNA (88.4)

Dendritic cells (DC) are central cells of the immune system that can stimulate or suppress immune responses, partially depending on their expression of costimulatory molecules. CD80 and CD86 are critical costimulatory molecules for both T cell responses and Th differentiation. Thus, silencing DC expression of CD80 and CD86, using siRNA, could potentially enable manipulation of immune responses. Since silencing of CD80 or CD86 in DC has not been reported, in this study we investigated the tolerogenesis and Th differentiation capacity of CD80/CD86 in DC after siRNA-mediated gene silencing. Gene silencing was performed by transfecting mouse bone marrow-derived DC with CD80 or CD86 siRNA. The gene silencing efficacy was measured by flow cytometry, RT-PCR, and real time PCR. DC that were transfected with CD80 or CD86 siRNA induced inhibition of T cell responses in MLR and generated T regulatory cells. The CD4+CD25+FoxP+ cell subset was significantly increased in a co-culture system that contained CD80- or CD86-silenced DC and allogeneic T cells. Furthermore, CD80 siRNA significantly decreased IFN-gamma, although a reduction in IL-4 was not observed. Conversely, CD86 siRNA significantly reduced IL-4 but did not reduce IFN-gamma. This study suggested, for the first time, that CD80 siRNA and CD86 siRNA can be useful tools for generating tolerogenic DC with a differential effect on modulating cytokine production.

Novel therapy for allergic disease through gene silencing of CD40 (37.7)

Gene silencing is a potent, selective, and easily-inducible method for specifically blocking expression of desired genes. Gene silencing strategies have been successfully tested in animal models of various diseases. However, the therapeutic potential of gene silencing allergic diseases has not yet been reported. CD40 is an important costimulatory molecule that plays a critical role in immune responses. We attempted to develop a new therapy for allergic diseases through gene silencing using a short hairpin siRNA-expressing vector (shRNA) specific to CD40. The allergic mouse model was made by intraperitoneal immunization with ovalbumin (OVA), followed by intranasal challenges with the same antigen. CD40 shRNA was administered before or after OVA immunization. CD40 shRNA treatment reduced CD40 expression in splenic DC, remarkably reduced nasal allergic symptoms, and decreased nasal eosinophilia. The OVA-specific T cell response was inhibited after CD40 shRNA treatment. Additionally, anti-OVA specific IgE was significantly decreased in CD40-shRNA treated mice, as detected by ELISA. The production of IL-4 and IL-5 was suppressed in the CD40-shRNA treated mice. Finally, CD40 shRNA facilitated the generation of regulatory T cells, in particular, the CD4+CD25+Foxp3+ subset of cells. This study, for the first time, has demonstrated a novel therapy for allergic disease through gene silencing.

Tolerogenic Vaccination Using IL-12 Gene-Silenced Dendritic Cells for Autoimmune Arthritis (131.9)

We have recently demonstrated that dendritic cell (DC)-mediated immune modulation and deviation can be accomplished through RNA interference (RNAi), highlighting the therapeutic potential of RNAi-modified DC as antigen-specific tolerogenic vaccines. To date, an RNAi-based vaccine has not been reported. The current study was designed to develop siRNA-modified DC as antigen-specific, tolerogenic vaccines for prevention and intervention of autoimmune arthritis. Using small interfering RNA (siRNA) that specifically targets IL-12p35 gene (IL-12 siRNA), we have generated a type of DC that exhibits multiple tolerogenic characteristics. Immunization with type II collagen (CII)-pulsed and IL-12 gene-silenced DC (CII-pulsed/gene-silenced DC) resulted in antigen-specific nonresponsiveness in T cell responses. Vaccination with CII-pulsed/gene-silenced DC prevented collagen-induced arthritis (CIA) onset in a murine rheumatoid arthritis model. Furthermore, administration of CII-pulsed/gene-silenced DC was sufficient to inhibit progression of CIA. The therapeutic effects were further evidenced by decreased clinical scores, inhibited inflammatory infiltrates, and suppressed T cell and B cell responses to CII. In conclusion, this study is the first to demonstrate the therapeutic utilization of RNAi-modified DC as antigen-specific tolerogenic vaccines for autoimmune arthritis.

Identification of viruses in patients with postviral olfactory dysfunction

Objective: Causative viruses of postviral olfactory dysfunction (PVOD) have not yet been identified. The aim of this study was to investigate causative viruses in patients with PVOD.

Study Design and Methods: Nasal discharge was collected from 24 patients with PVOD. We investigated the presence of 10 viruses in nasal discharge and examined the time course, with regard to changes in olfactory dysfunction and nasal obstruction in patients with PVOD, using questionnaires, acoustic rhinometry, and olfactory tests.

Results: Rhinoviruses were detected in 10 patients by electrophoresis. Rhinoviruses were also confirmed in four patients by nucleotide sequences. Viral serotypes were identified to be human rhinovirus (HRV)‐40, HRV‐75, HRV‐78, and HRV‐80. One of the four patients complained of anosmia, whereas another complained of dysosmia. Olfactory testing did not show significant improvement at 4, 8, 11, and 24 weeks after the first visit in the four patients, although results of acoustic rhinometry significantly improved. Two of the four patients complained of olfactory dysfunction even 6 months after the first visit. Coronavirus and parainfluenza virus were detected in one patient each, and Epstein‐Barr viruses were detected in three patients.

Conclusions: This study for the first time detected rhinovirus, coronavirus, parainfluenza virus, and Epstein‐Barr virus in nasal discharge of patients with PVOD. Furthermore, the present study suggests that rhinoviruses can cause olfactory dysfunction through mechanisms other than nasal obstruction and that rhinoviruses can induce various severities and different time courses of olfactory dysfunction.

Intranasal CpG DNA therapy during allergen exposure in allergic rhinitis

OBJECTIVE

1) To estimate the effectiveness of intranasal administration of CpG DNA alone on allergic rhinitis compared with intradermal administration; and 2) to find out how CpG DNA therapy is useful in treatment of allergic rhinitis.

STUDY DESIGN

Mice were intraperitoneally sensitized and intranasally challenged with Japanese cedar. Therapy with CpG DNA alone was also performed during challenge, either intranasally or intradermally. Immunologic variables and nasal symptom were studied.

RESULTS

Intranasal administration of CpG DNA alone significantly reduced the levels of IgE, IL-5 productions from nasal lymphocytes and splenocytes, nasal eosinophilia, and nasal symptoms, although intradermal administration of CpG DNA alone showed no significant reduction.

CONCLUSION

This study demonstrated that CpG DNA has effects not only on splenocytes but also on nasal lymphocytes to attenuate allergic rhinitis, and that intranasal administration, but not intradermal administration, of CpG DNA alone during allergen exposure is useful for control of allergic rhinitis.

Preventing autoimmune arthritis using antigen-specific immature dendritic cells: a novel tolerogenic vaccine

Conventional treatments for autoimmune diseases have relied heavily on nonspecific immune suppressants, which possess a variety of adverse effects without inhibiting the autoimmune process in a specific manner. In the present study we demonstrate the effectiveness of antigen-specific, maturation-resistant, tolerogenic dendritic cells (DC) in suppressing collagen-induced arthritis, a murine model of rheumatoid arthritis. Treatment of DC progenitors with the NF-κB inhibiting agent LF 15-0195 (LF) resulted in a population of tolerogenic DC that are characterized by low expression of MHC class II, CD40, and CD86 molecules, as well as by poor allostimulatory capacity in a mixed leukocyte reaction. Administering LF-treated DC pulsed with keyhole limpet hemocyanin antigen to naïve mice resulted hyporesponsiveness specific for this antigen. Furthermore, administration of LF-treated DC to mice with collagen-induced arthritis resulted in an improved clinical score, in an inhibited antigen-specific T-cell response, and in reduced antibody response to the collagen. The efficacy of LF-treated DC in preventing arthritis was substantiated by histological examination, which revealed a significant decrease in inflammatory cell infiltration in the joints. In conclusion, we demonstrate that in vitro-generated antigen-specific immature DC may have important potential as a tolerogenic vaccine for the treatment of autoimmune arthritis.