Fas-ligand-expressing adenovirus-transfected dendritic cells decrease allergen-specific T cells and airway inflammation in a murine model of asthma

Gene Therapy for Immunoglobulin E, Complement-Mediated, and Eosinophilic Disorders

Immunoglobulin E, complement, and eosinophils play an important role in host defense, but dysfunction of each of these components can lead to a variety of human disorders. In this review, we summarize how investigators have adapted gene therapy and antisense technology to modulate immunoglobulin E, complement, and/or eosinophil levels to treat these disorders.

Apoptotic cell death in disease-Current understanding of the NCCD 2023

Apoptosis is a form of regulated cell death (RCD) that involves proteases of the caspase family. Pharmacological and genetic strategies that experimentally inhibit or delay apoptosis in mammalian systems have elucidated the key contribution of this process not only to (post-)embryonic development and adult tissue homeostasis, but also to the etiology of multiple human disorders. Consistent with this notion, while defects in the molecular machinery for apoptotic cell death impair organismal development and promote oncogenesis, the unwarranted activation of apoptosis promotes cell loss and tissue damage in the context of various neurological, cardiovascular, renal, hepatic, infectious, neoplastic and inflammatory conditions. Here, the Nomenclature Committee on Cell Death (NCCD) gathered to critically summarize an abundant pre-clinical literature mechanistically linking the core apoptotic apparatus to organismal homeostasis in the context of disease.

Dendritic cells in pregnancy and pregnancy-associated diseases

Dendritic cells (DCs) play a critical immuno-modulating role in pregnancy, which requires the maternal immune system to tolerate semiallogeneic fetus and at the same time to maintain adequate defense against pathogens. DCs interact closely with other immune components such as T cells, natural killer cells and macrophages, as well as the endocrine system to keep a pregnancy-friendly environment. Aberrant DC activities have been related to various pregnancy-associated diseases such as recurrent spontaneous abortion, preterm birth, pre-eclampsia, peripartum cardiomyopathy and infectious pregnancy complications. These findings make DCs an attractive candidate for prevention or therapy on the pregnancy-associated diseases. Here, we review recent findings that provide new insights into the roles of DCs in pregnancy and the related diseases. We also discuss the medical potentials to manipulate DCs in clinics. Whereas this is an emerging area with much work remaining, we anticipate that a better understanding of the role of DCs in maternal-fetal immunotolerance and a therapeutic manipulation of DCs will help women suffering from the pregnancy-associated diseases.

Fas Signaling in Dendritic Cells Mediates Th2 Polarization in HDM-Induced Allergic Pulmonary Inflammation

Fas-Fas ligand (FasL) signaling plays an important role in the development of allergic inflammation, but the cellular and molecular mechanisms are still not well known. By using the bone marrow-derived dendritic cell (BMDC) transfer-induced pulmonary inflammation model, we found that house dust mite (HDM)-stimulated FAS-deficient BMDCs induced higher Th2-mediated allergic inflammation, associated with increased mucus production and eosinophilic inflammation. Moreover, FAS-deficient BMDCs promoted Th2 cell differentiation upon HDM stimulation in vitro. Compared to wild-type BMDCs, the Fas-deficient BMDCs had increased ERK activity and decreased IL-12 production upon HDM stimulation. Inhibition of ERK activity could largely increase IL-12 production, consequently restored the increased Th2 cytokine expression of OT-II CD4⁺ T cells activated by Fas-deficient BMDCs. Thus, our results uncover an important role of DC-specific Fas signaling in Th2 differentiation and allergic inflammation, and modulation of Fas signaling in DCs may offer a useful strategy for the treatment of allergic inflammatory diseases.

A biodegradable killer microparticle to selectively deplete antigen-specific T cells in vitro and in vivo

The specific eradication of pathogenic T cells for the treatment of allograft rejections and autoimmune disorders without impairment of overall immune function is a fundamental goal. Here, cell-sized poly(lactic-co-glycolic acid) microparticles (PLGA MPs) were prepared as a scaffold to co-display the peptide/major histocompatibility complex (pMHC, target antigen) and anti-Fas monoclonal antibody (apoptosis-inducing molecule) for the generation of biodegradable killer MPs. Ovalbumin (OVA) antigen-targeted killer MPs significantly depleted OVA-specific CD8+ T cells in an antigen-specific manner, both in vitro and in OT-1 mice. After intravenous administration, the killer MPs predominantly accumulated in the liver, lungs, and gut of OT-1 mice with a retention time of up to 48 hours. The killing effects exerted by killer MPs persisted for 4 days after two injections. Moreover, the H-2Kb alloantigen-targeted killer MPs were able to eliminate low-frequency alloreactive T cells and prolong alloskin graft survival for 41.5 days in bm1 mice. Our data indicate that PLGA-based killer MPs are capable of specifically depleting pathogenic T cells, which highlights their therapeutic potential for treating allograft rejection and autoimmune disorders.

Long-acting β2-adrenoreceptor agonists suppress type 1 interferon expression in human plasmacytoid dendritic cells via epigenetic regulation

The combination of inhaled long-acting β2-adrenoreceptor (LABA) and inhaled glucocorticoid (ICS) is a major therapy for asthma. However, the increased risk of infection is still a concern. Plasmacytoid dendritic cells (pDCs) are the predominant cells producing type 1 interferon (IFN) against infection. The effect of LABA/ICS on type 1 IFN expression in human pDCs is unknown. Circulating pDCs were isolated from healthy human subjects and were pretreated with glucocorticoid (GCS), LABA or a cAMP analog, and were stimulated with Toll-like receptor (TLR) agonist CpG (TLR9) or imiquimod (TLR7) in the presence of IL-3. The expression of type 1 IFN (IFN-α/β) were measured by ELISA. The mechanisms were investigated using receptor antagonists, pathway inhibitors, Western blotting and chromatin immunoprecipitation. GCS suppressed TLR-induced IFN-α expression, and LABA enhanced the suppressive effect. LABA alone also suppressed TLR-induced IFN-α/β expression, and the effect was reversed by the β2-adrenoreceptor antagonist ICI118551. Dibutyryl-cAMP, a cAMP analog, conferred a similar suppressive effect, and the effect was abrogated by the exchange protein directly activated by cAMP (Epac) inhibitor HJC0197 or intracellular free Ca²⁺ chelator BAPTA-AM. Formoterol suppressed TLR-induced phosphorylation of mitogen-activated protein kinase (MAPK)-p38/ERK. Formoterol suppressed interferon regulatory factor (IRF)-3/IRF-7 expression. Formoterol suppressed CpG-induced translocation of H3K4 specific methyltransferase WDR5 and suppressed H3K4 trimethylation in the IFNA and IFNB gene promoter region. LABA suppressed TLR7/9-induced type 1 IFNs production, at least partly, via the β₂-adrenoreceptor-cAMP-Epac-Ca²⁺, IRF-3/IRF-7, the MAPK-p38/ERK pathway, and epigenetic regulation by suppressing histone H3K4 trimethylation through inhibiting the translocation of WDR5 from cytoplasm to nucleus. LABA may interfere with anti-viral immunity.

An Antigen-Presenting and Apoptosis-Inducing Polymer Microparticle Prolongs Alloskin Graft Survival by Selectively and Markedly Depleting Alloreactive CD8+ T Cells

Selectively depleting the pathogenic T cells is a fundamental strategy for the treatment of allograft rejection and autoimmune disease since it retains the overall immune function of host. The concept of killer artificial antigen-presenting cells (KaAPCs) has been developed by co-coupling peptide–major histocompatibility complex (pMHC) multimer and anti-Fas monoclonal antibody (mAb) onto the polymeric microparticles (MPs) to induce the apoptosis of antigen-specific T cells. But little information is available about its in vivo therapeutic potential and mechanism. In this study, polyethylenimine (PEI)-coated poly lactic-co-glycolic acid microparticle (PLGA MP) was fabricated as a cell-sized scaffold to covalently co-couple H-2K^b-Ig dimer and anti-Fas mAb for the generation of alloantigen-presenting and apoptosis-inducing MPs. Intravenous infusions of the biodegradable KaAPCs prolonged the alloskin graft survival for 43 days in a single MHC-mismatched murine model, depleted the most of H-2K^b-alloreactive CD8⁺ T cells in peripheral blood, spleen, and alloskin graft in an antigen-specific manner and anti-Fas-dependent fashion. The cell-sized KaAPCs circulated throughout vasculature into liver, kidney, spleen, lymph nodes, lung, and heart, but few ones into local allograft at early stage, with a retention time up to 36 h in vivo. They colocalized with CD8⁺ T cells in secondary lymphoid organs while few ones contacted with CD4⁺ T cells, B cells, macrophage, and dendritic cells, or internalized by phagocytes. Importantly, the KaAPC treatment did not significantly impair the native T cell repertoire or non-pathogenic immune cells, did not obviously suppress the overall immune function of host, and did not lead to visible organ toxicity. Our results strongly document the high potential of PLGA MP-based KaAPCs as a novel antigen-specific immunotherapy for allograft rejection and autoimmune disorder. The in vivo mechanism of alloinhibition, tissue distribution, and biosafety were also initially characterized, which will facilitate its translational studies from bench to bedside.

Vaccination with different doses of Dermatophagoides farinae in a mouse model of allergic asthma

BACKGROUND

The efficacy of vaccination with different doses of a vaccine has not been clarified. The purpose of this study was to investigate the relationship between the doses of purified house dust mite allergen, and allergic airway inflammation and airway reactivity in a mouse model of allergic asthma.

METHODS

C57BL/6 mice were sensitized with Dermatophagoides farinae (Der f) and randomly treated with saline, 0.1, 1, or 2 mg Der f vaccine, respectively. The airway hyperresponsiveness, the numbers of total cells and eosinophils and the levels of interferon-γ and interleukin (IL)-4 in the bronchoalveolar lavage fluid (BALF) from individual mice were measured. The percentages of CD11c CD86 and CD11c MHC II+ dendritic cells were characterized, and the levels of IL-12 in the supernatants of cultured dendritic cells were measured.

RESULTS

The airway hyperresponsiveness, the numbers of total cells and eosinophils in the BALF and the percentages of CD11c CD86 and CD11c MHC II+ dendritic cells were associated with immunologic downregulation. The levels of IFN-γ in the BALF and the levels of IL-12 in the supernatants of cultured dendritic cells were associated with immunologic upregulation. It was found that vaccination with the medium dose of Der f showed a stronger inhibitory effect.

CONCLUSIONS

There seems to be a dose-dependent response between allergen and both airway inflammation and hyperreactivity in the mouse model of allergic asthma.

Blocking Fas ligand on leukocytes attenuates kidney ischemia-reperfusion injury

Inflammation contributes to the pathogenesis of ischemic acute kidney injury (AKI), and T cells mediate the early phase of ischemia-reperfusion injury (IRI). The Fas/Fas ligand (FasL) pathway modulates the balance of T cell subsets in the peripheral circulation as well as multiple inflammatory responses, suggesting that FasL may mediate ischemic AKI. Here, we induced bilateral renal IRI in mice bearing a loss-of-function mutation of FasL (the gld mutation) and in wild-type mice. Compared with wild-type mice, serum creatinine was lower in gld mice (1.4 ± 0.9 mg/dl versus 2.6 ± 0.4) at 24 hours after IRI (P<0.05). In addition, gld mice had fewer TNF-α-producing T lymphocytes in the kidneys and renal lymph nodes. Furthermore, pharmacologic blockade of FasL protected the kidneys of wild-type mice from IRI. Analysis of bone marrow chimeric mice suggested that the pathogenic effect of FasL involves leukocytes; reconstitution of wild-type mice with gld splenocytes attenuated IRI. In contrast, reconstitution of gld mice with wild-type splenocytes enhanced IRI. These data demonstrate that FasL, particularly on leukocytes, mediates ischemic AKI.

Alleviating allergic airway diseases by means of short-term administration of IL-2 and dexamethasone

BACKGROUND

IL-2 combined with dexamethasone can upregulate regulatory T (Treg) cells, but the mechanism is still under exploration.

OBJECTIVE

Although previous studies focused on upregulating Treg cells in normal mice, here we investigated whether the IL-2 and dexamethasone combination treatment can upregulate Treg cells in pathological conditions, specifically in alleviating allergic airway disease. We also examined the potential pathway involved in Treg cell upregulation by IL-2 and dexamethasone.

METHODS

We evaluated the dose of IL-2 and dexamethasone required to upregulate Treg cells in vivo and in vitro. We also tested IL-2 and dexamethasone in the intervention of allergic airway disease in a murine model.

RESULTS

We found that administration of 400,000 IU of IL-2 and 0.1 mg of dexamethasone per mouse was effective in upregulating Treg cells, as well as in alleviating allergic airway disease in an established animal model, but this phenomenon disappeared after anti-CD25 antibody administration. We discovered that an in vitro low dose of IL-2 can protect Treg cells did not protect CD4(+)CD25(-) cells from dexamethasone-induced apoptosis by affecting forkhead box O3a phosphorylation through the Akt and serum and glucocorticoid-induced protein kinase pathways.

CONCLUSIONS

IL-2/dexamethasone treatment can alleviate existing allergic airway diseases by upregulating Treg cells in vivo. A low dose of IL-2 (10(-9) to 10(-11) mol/L) can protect Treg cells but not CD4(+)CD25(-) cells from dexamethasone-induced apoptosis in vitro, thereby explaining a possible mechanism of increased proportion of Treg cells.

Killer artificial antigen-presenting cells: the synthetic embodiment of a 'guided missile'

At present, the treatment of T-cell-dependent autoimmune diseases relies exclusively on strategies leading to nonspecific suppression of the immune systems causing a substantial reduced ability to control concomitant infections or malignancies. Furthermore, long-term treatment with most drugs is accompanied by several serious adverse effects and does not consequently result in cure of the primary immunological malfunction. By contrast, antigen-specific immunotherapy offers the potential to achieve the highest therapeutic efficiency in accordance with minimal adverse effects. Therefore, several studies have been performed utilizing antigen-presenting cells specifically engineered to deplete allo- or antigen-specific T cells ('guided missiles'). Many of these strategies take advantage of the Fas/Fas ligand signaling pathway to efficiently induce antigen-presenting cell-mediated apoptosis in targeted T cells. In this article, we discuss the advantages and shortcomings of a novel non-cell-based 'killer artificial antigen-presenting cell' strategy, developed to overcome obstacles related to current cell-based approaches for the treatment of T-cell-mediated autoimmunity.

Dendritic cell co-transfected with FasL and allergen genes induces T cell tolerance and decreases airway inflammation in allergen induced murine model

Dendritic cell (DC) displays tremendous functional plasticity in response to antigens and plays important roles in inducing immune tolerance. In this study, we investigated the effects of immature DC (imDC) co-transfected with FasL and allergen Der p2 genes (FasL-Der p2-DC) on inducing immune tolerance and modulating airway inflammation of Der p2-induced allergic mice. Moreover, we compared the effects of FasL-Der p2-DC with FasL-transfected imDC (FasL-DC) and Der p2-transfected imDC (Der p2-DC) respectively. Results showed that FasL-Der p2-DC and Der p2-pulsed FasL-DC induced T cell unresponsiveness to Der p2 via apoptosis. Der p2-DC could induce T cell hyporesponsiveness to Der p2. FasL-Der p2-DC, FasL-DC and Der p2-DC could inhibit Th2 response and reduce allergic airway inflammation. FasL-Der p2-DC was more effective than FasL-DC and Der p2-DC, respectively. These results demonstrate that FasL and allergen genes co-expressing DC might be a promising approach to allergy therapy.

Therapy with FasL-gene-modified dendritic cells confers a protective microenvironment in murine pregnancy

Analysis of the expression of FasL in the local decidua of pregnant mice and examination of the apoptosis of T cells in peripheral blood and local decidua indicated that adoptive transference of FasL-gene-modified dendritic cells may induce pregnancy immune tolerance by increasing FasL expression in the maternal-fetal interface and inducing the apoptosis of T cells in local decidua but not the peripheral blood.

Fas ligand expression on T cells is sufficient to prevent prolonged airway inflammation in a murine model of asthma

Our previous studies revealed that, in a murine model of asthma, mice that received Fas-deficient T cells developed a prolonged phase of airway inflammation, mucus production, and airway hyperreactivity that failed to resolve even 6 weeks after the last challenge. To investigate how Fas-Fas ligand (FasL) interaction occurs between T cells and other cells in vivo, Gld mice with abnormalities of the FasL signaling pathway were used. The reconstituted mice were made by transferring T cells from B6 or Gld mice to Rag(-/-) or FasL-deficient Rag(-/-) mice. We found that Rag(-/-) mice that received B6 T cells resolved the airway inflammation, whereas FasL-deficient Rag(-/-) mice that received Gld T cells developed a prolonged airway inflammation at Day 28, with decreased IFN-gamma production. Both FasL-deficient Rag(-/-) mice that received B6 T cells and Rag(-/-) mice that received Gld T cells also had completely resolved their airway inflammation by Day 28 after challenge. Interestingly, FasL-deficient Rag(-/-) mice that received Gld T cells eventually resolved airway inflammation at Day 42, with a similar level of IFN-gamma production to that of control group. These results demonstrate that FasL expression on either T cells only or non-T cells only was sufficient for the eventual resolution of airway inflammation, and the prolonged airway inflammation in FasL-deficient Rag(-/-) mice that received Gld T cells was correlated with decreased IFN-gamma production by Gld T cells.

The role of costimulatory molecules in allergic disease and asthma

The prevalence of allergic diseases has increased rapidly in recent years. It is well established that the deleterious allergic response is initiated by T-cell recognition of major histocompatibility class II-peptide complexes at the surface of antigen-presenting cells. While this first signal gives antigen specificity to the adaptive immune response, a second nonspecific costimulatory signal is required by T cells to become fully activated. This signal is provided by interactions between antigen-presenting cells and T cells through molecules borne at the surfaces of the two cell types. Depending on the type of molecules involved, this secondary signal can promote the development of an inflammatory allergic reaction or may favor immune regulation. Several molecules of the B7 family (CD80, CD86, PD-1, ICOS, CTLA-4) and tumor necrosis factor receptor family (OX40, CD30, 4-1BB, Fas, CD27, CD40) play an important role in delivering costimulatory signals in early and late phases of allergic response. Therefore, costimulatory molecules involved in promotion or prevention of allergic immune responses are potential targets for the development of novel therapeutic approaches. This review aims to recapitulate our current understanding of the relationship between allergic diseases and costimulatory molecules.

Adoptive transfer of mFas ligand into dendritic cells influences the spontaneous resorption rate in the CBA/J x DBA/2 mouse model

OBJECTIVE

To investigate the effect of mFasL dendritic cells (DC) on the embryo resorption rate in the CBA/J x DBA/2 abortion mouse model.

DESIGN

Experimental study.

SETTING

University hospital in a major city in China.

ANIMAL(S)

101 CBA/J mice and 50 DBA/2 mice.

INTERVENTION(S)

We constructed the eukaryotic expression vector pcDNA3.1-mFasL, derived the DCs from bone marrow of DBA/2 mice, and transfected the DCs with pcDNA3.1-mFasL. The abortion mouse model were established by mating female CBA/J mice with DBA/2 mice. Via the CBA/J x DBA/2 abortion mouse model, five groups were established: group 1: abortion model without treatment; group 2: abortion mouse model injected with DC culture medium (DCCM); group 3: abortion mouse model injected with DC; group 4: abortion mouse model injected with empty plasmid pcDNA3.1-DC; group 5: abortion model mouse injected with pcDNA3.1-FasL-DC.

MAIN OUTCOME MEASURE(S)

Comparison of difference in the embryo resorption rates of the CBA/J x DBA/2 abortion mouse model treated with either pcDNA3.1-mFasL-DC or different controls observed on gestation days 12 to 14.

RESULT(S)

The embryo resorption rate was statistically significantly decreased in group 3 treated with DC and group 4 with empty plasmid pcDNA3.1-DC when they compared with group 1 (no treatment for abortion mouse model) and group 2 (injected with DC culture medium, DCCM). Furthermore, abortion model group 5 (injected with pcDNA3.1-mFasL-DC) showed a statistically significantly decreased in embryo resorption rate when compared with the other four groups, including groups 1 and 2 and groups 3 and group 4.

CONCLUSION(S)

Adoptive transfer of mFasL-DC can statistically significantly reduce the embryo resorption rate in the CBA/J x DBA/2 abortion mouse model.

Differential effects of dendritic cell transfer on airway hyperresponsiveness and inflammation

Dendritic cells (DCs) are considered to be the most efficient antigen-presenting cells. Intratracheal administration of allergen-pulsed bone marrow-derived dendritic cells (BMDCs) before allergen challenge induces airway hyperresponsiveness (AHR) and inflammation. Ovalbumin (OVA)-pulsed BMDCs from wild-type (WT) mice were transferred into naive WT, CD4(-/-), CD8(-/-), or IL-13(-/-) mice. Two days (short protocol) or 10 days (long protocol) after BMDC transfer, mice were challenged with 1% OVA for 3 days and assayed 2 days later. Transfer of OVA-primed BMDCs into BALB/c or C57BL/6 mice elicited AHR in both protocols. Airway eosinophilia, Th2 cytokines, or goblet cell metaplasia were increased in the long but not short protocol. Lung T cells from both protocols produced Th2 cytokines in response to OVA in vitro. Carboxyfluorescein diacetate succinimidylester-labeled BMDCs were observed in bronchoalveolar lavage (BAL) fluid and lung parenchyma at early time points, and were detected in draining lymph nodes 48 hours after transfer. CD8(-/-) mice developed AHR comparable to WT mice in the short protocol, but decreased levels of AHR, airway eosinophilia, Th2 cytokines in BAL fluid, and goblet cell metaplasia compared with WT mice in the long protocol. CD4(-/-) or IL-13(-/-) mice did not develop AHR or airway inflammation in either protocol. These data suggest that allergen-pulsed BMDCs initiate development of AHR that is dependent initially on CD4(+) T cells, and at later time periods on CD8+ T cells and IL-13. Thus, the timing of allergen challenge after transfer of allergen-pulsed BMDC affects the development of AHR and airway inflammation.

Ozone inhalation induces exacerbation of eosinophilic airway inflammation and hyperresponsiveness in allergen-sensitized mice

BACKGROUND

Ozone (O(3)) exposure evokes asthma exacerbations by mechanisms that are poorly understood. We used a murine model to characterize the effects of O(3) on allergic airway inflammation and hyperresponsiveness and to identify factors that might contribute to the O(3)-induced exacerbation of asthma.

METHODS

BALB/c mice were sensitized and challenged with Aspergillus fumigatus (Af). A group of sensitized and challenged mice was exposed to 3.0 ppm of O(3) for 2 h and studied 12 h later (96 h after Af challenge). Naive mice and mice exposed to O(3) alone were used as controls. Bronchoalveolar lavage (BAL) cellular and cytokine content, lung function [enhanced pause (P(enh))], isometric force generation by tracheal rings and gene and protein expression of Fas and FasL were assessed. Apoptosis of eosinophils was quantified by FACS.

RESULTS

In sensitized mice allergen challenge induced a significant increase of P(enh) and contractile force in tracheal rings that peaked 24 h after challenge and resolved by 96 h. O(3) inhalation induced an exacerbation of airway hyperresponsiveness accompanied by recurrence of neutrophils and enhancement of eosinophils 96 h after allergen challenge. The combination of allergen and O(3) exposure inhibited Fas and FasL gene and protein expression and eosinophil apoptosis and increased interleukin-5 (IL-5), granulocyte-macrophage-colony stimulating factor (GM-CSF) and G-CSF protein levels.

CONCLUSIONS

O(3) affects airway responsiveness of allergen-primed airways indirectly by increasing viability of eosinophils and eosinophil-mediated pathological changes.