鼠疫F1-V重组蛋白疫苗滴鼻免疫应答效果的研究

目的 以重组霍乱毒素B亚单位（rCT-B）为鼠疫F1-V重组蛋白的佐剂制备黏膜疫苗,观察小鼠诱导的黏膜免疫和系统免疫应答效果。方法以制备的鼠疫黏膜疫苗滴鼻免疫小鼠4次免疫后,采用间接ELISA检测血清特异性抗F1-V的IgG和IgA抗体及抗体亚型分类,检测鼻咽喉、肺、小肠及阴道灌洗液中特异性抗F1-V的黏膜分泌型IgA;采用流式细胞术检测鼻相关淋巴组织淋巴细胞、脾淋巴细胞、肠系膜淋巴结及小肠PP结T淋巴细胞表型的变化。结果以rCT-B为佐剂的鼠疫F1-V重组蛋白黏膜疫苗滴鼻免疫后,能够诱导血清中IgG、IgA抗体比正常对照组显著升高（P〈0．01）,同时诱导鼻咽、肺、小肠和阴道内特异性黏膜抗体升高,尤其是肺和生殖道冲冼液内抗体升高极为显著（P〈0．01）。与单纯的F1-V组相比,不同剂量比例疫苗组都能诱导较高、较快的血清IgG、IgA和黏膜sIgA,其中1：2疫苗组能诱导更强的系统免疫和黏膜免疫,但是相比之下,5：1疫苗组是最合适的免疫剂量。结论rCT-B佐剂不仅能提高鼠疫F1-V黏膜疫苗的系统全身免疫应答,还能促进诱导呼吸道、消化道和生殖道等局部黏膜sIgA抗体,增强局部免疫应答,提示rCT-B佐剂能显著提高鼠疫感染的免疫应答作用,这为下一步疫苗的免疫保护评价奠定了基础。     

Resiquimod, a new immune response modifier from the family of imidazoquinolinamines, inhibits allergen-induced Th2 responses, airway inflammation and airway hyper-reactivity in mice

BACKGROUND: Allergen-induced sensitization and airway disease are the results of adverse immune reactions against environmental antigens that may be prevented or inhibited by immune modifying strategies. OBJECTIVE: To investigate the effects of the novel immune response modifier resiquimod (R-848), from the family of imidazol-derivates, in a murine model of allergen-mediated Th2-immune responses and concomitant airway inflammation and airway hyper-reactivity. METHODS: BALB/c mice were systemically sensitized with ovalbumin (OVA) on days 1 and 14 and challenged with OVA aerosol on days 28 and 29. R-848 was applied intranasally to sensitized animals once prior to the first allergen airway challenge, on day 27. RESULTS: A single application of R-848 significantly reduced numbers of eosinophils and lymphocytes in bronchoalveolar lavage fluid and inhibited mucus gland hyperplasia, compared with sensitized and challenged controls. Associated with the decrease in airway inflammation, single intranasal treatment with R-848 abolished the development of airway hyper-reactivity after allergen sensitization and airway challenges. Additionally, Th2-cytokine production in lung tissues from sensitized and R-848-treated animals was reduced, whereas IL-12 and IFN-gamma production was increased, compared with non-treated sensitized mice. CONCLUSION: These data indicate that R-848 effectively inhibits allergen-induced airway inflammation and hyper-reactivity by modulation of increased Th2-immune responses.     

Apolipoprotein B100 is a suppressor of Staphylococcus aureus‐induced innate immune responses in humans and mice

Plasma lipoproteins such as LDL (low‐density lipoprotein) are important therapeutic targets as they play a crucial role in macrophage biology and metabolic disorders. The impact of lipoprotein profiles on host defense pathways against Gram‐positive bacteria is poorly understood. In this report, we discovered that human serum lipoproteins bind to lipoteichoic acid (LTA) from Staphylococcus aureus and thereby alter the immune response to these bacteria. Size‐exclusion chromatography and solid‐phase‐binding analysis of serum revealed the direct interaction of LTA with apolipoproteins (Apo) B100, ApoA1, and ApoA2. Only ApoB100 and the corresponding LDL exerted biological effects as this binding significantly inhibited LTA‐induced cytokine releases from human and murine immune cells. Serum from hypercholesterolemic mice or humans significantly diminished cytokine induction in response to S. aureus or its LTA. Sera taken from the patients with familial hypercholesterolemia before and after ApoB100‐directed immuno‐apheresis confirmed that ApoB100 inhibited LTA‐induced inflammation in humans. In addition, mice in which LDL secretion was pharmacologically inhibited, displayed significantly increased serum cytokine levels upon infection with S. aureus in vivo. The present study identifies ApoB100 as an important suppressor of innate immune activation in response to S. aureus and its LTA.     

Age-associated dysregulation of microglial activation is coupled with enhanced blood-brain barrier permeability and pathology in APP/PS1 mice

Aging adversely affects inflammatory processes in the brain, which has important implications in the context of disease progression. It has been proposed that microglia become dysfunctional with age and may lose their neuroprotective properties leading to chronic neurodegeneration. Here, we sought to characterize inflammatory changes in a mouse model of Alzheimer's disease and to delineate differences between normal aging and those associated with disease pathology. A proinflammatory profile, characterized by the upregulation of markers of classical activation, was evident in APPswe/PS1dE9 mice, associated with increased interferon-γ (IFNγ) concentration and dysregulation of mechanisms designed to limit the proinflammatory response. The data indicate that microglia are not less active with age but alter their phenotype; indeed, changes observed in the deactivation state appear to relate to aging rather than disease pathology. We hypothesize that disruption of the blood-brain barrier, in tandem with an enhanced chemokine profile, permits the infiltration of immune cells serving to reinforce classical activation of microglia through their enhanced responsiveness to IFNγ.     

Morpholino-induced exon skipping stimulates cell-mediated and humoral responses to dystrophin in mdx mice

Exon skipping is a promising genetic therapeutic strategy for restoring dystrophin expression in the treatment of Duchenne muscular dystrophy (DMD). The potential for newly synthesized dystrophin to trigger an immune response in DMD patients, however, is not well established. We have evaluated the effect of chronic phosphorodiamidate morpholino oligomer (PMO) treatment on skeletal muscle pathology and asked whether sustained dystrophin expression elicits a dystrophin-specific autoimmune response. Here, two independent cohorts of dystrophic mdx mice were treated chronically with either 800 mg/kg/month PMO for 6 months (n = 8) or 100 mg/kg/week PMO for 12 weeks (n = 11). We found that significant muscle inflammation persisted after exon skipping in skeletal muscle. Evaluation of humoral responses showed serum-circulating antibodies directed against de novo dystrophin in a subset of mice, as assessed both by Western blotting and immunofluorescent staining; however, no dystrophin-specific antibodies were observed in the control saline-treated mdx cohorts (n = 8) or in aged (12-month-old) mdx mice with expanded ‘revertant’ dystrophin-expressing fibers. Reactive antibodies recognized both full-length and truncated exon-skipped dystrophin isoforms in mouse skeletal muscle. We found more antigen-specific T-cell cytokine responses (e.g. IFN-g, IL-2) in dystrophin antibody-positive mice than in dystrophin antibody-negative mice. We also found expression of major histocompatibility complex class I on some of the dystrophin-expressing fibers along with CD8+ and perforin-positive T cells in the vicinity, suggesting an activation of cell-mediated damage had occurred in the muscle. Evaluation of complement membrane attack complex (MAC) deposition on the muscle fibers further revealed lower MAC deposition on muscle fibers of dystrophin antibody-negative mice than on those of dystrophin antibody-positive mice. Our results indicate that de novo dystrophin expression after exon skipping can trigger both cell-mediated and humoral immune responses in mdx mice. Our data highlights the need to further investigate the autoimmune response and its long-term consequences after exon-skipping therapy. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Fibrous nanocellulose,crystalline nanocellulose,carbon nanotubes,and crocidolite asbestos elicit disparate immune responses upon pharyngeal aspiration in mice

With the rapid development of synthetic alternatives to mineral fibers, their possible effects on the environment and human health have become recognized as important issues worldwide. This study investigated effects of four fibrous materials, i.e. nanofibrillar/nanocrystalline celluloses (NCF and CNC), single-walled carbon nanotubes (CNTs), and crocidolite asbestos (ASB), on pulmonary inflammation and immune responses found in the lungs, as well as the effects on spleen and peripheral blood immune cell subsets. BALB/c mice were given NCF, CNC, CNT, and ASB on Day 1 by oropharyngeal aspiration. At 14 days post-exposure, the animals were evaluated. Total cell number, mononuclear phagocytes, polymorphonuclear leukocytes, lymphocytes, and LDH levels were significantly increased in ASB and CNT-exposed mice. Expression of cytokines and chemokines in bronchoalveolar lavage (BAL) was quite different in mice exposed to four particle types, as well as expression of antigen presentation-related surface proteins on BAL cells. The results revealed that pulmonary exposure to fibrous materials led to discrete local immune cell polarization patterns with a T_H2-like response caused by ASB and T_H1-like immune reaction to NCF, while CNT and CNC caused non-classical or non-uniform responses. These alterations in immune response following pulmonary exposure should be taken into account when testing the applicability of new nanosized materials with fibrous morphology.     

Modulating effect of a new ester, 28-O-phosphatidylbetulin (DAPB), obtained from hen egg yolk lecithin and betulin on lymphocyte subsets and humoral immune response in mice

Context: Leaf extracts of plants of the genus Betula have traditionally been used as diuretic, anti-rheumatic and diaphoretic preparations. One of the main active ingredients of Betula bark is betulin, lupane-type triterpene alcohol, with multiple biological activities.

Objectives: The aim of this study was to investigate in vitro and in vivo immunomodulatory effects of a newly synthesized ester of betulin: 28-O-phosphatidylbetulin [28-O-(1,2-diacyl-sn-glycero-3-phospho)-betulin, DAPB] in comparison with betulin in mice.

Materials and methods: Cytotoxic activity of DAPB or betulin was tested against non-cancer (D10.G4.1 and J774E.1) and cancer (GL-1; CL-1 and Jurkat) cell lines. The in vivo part assessed total lymphocyte count, weight ratio and subsets of lymphocytes in the lymphatic organs, and humoral immune response to sheep erythrocytes (SRBC).

Results: In vitro assay showed that DAPB, contrary to betulin, had no antiproliferative activity. Exposure to four doses of DAPB increased the absolute count of immature CD4⁺CD8⁺ thymic cells as well as the percentage and absolute count of mature CD4⁺ and CD8⁺ thymocytes. DAPB enhanced the percentage or absolute count of CD3⁺ cells in spleen and lymph nodes with corresponding decrease in the percentage and/or absolute count of CD19⁺ cells. Both DAPB and betulin enhanced the percentage and absolute count of CD8⁺ lymphocytes in lymph nodes. In SRBC-immunized mice, betulin contrary to DAPB enhanced the number of splenocytes producing anti-SRBC antibodies (PFC). Both DAPB and betulin increased the level of total (IgM?+?IgG) and IgG titers.

Conclusion: Despite the lack of cytotoxic activity, DAPB shows valuable immunomodulatory properties.     

Differential effect of hyperglycaemia on the immune response in an experimental model of diabetes in BALB/cByJ and C57Bl/6J mice: participation of oxidative stress

Diabetes is associated with an increased risk of death from infectious disease. Hyperglycaemia has been identified as the main factor contributing to the development of diseases associated with diabetes mellitus. However, experimental evidence indicates individual susceptibility to develop complications of diabetes. In this context, the aim of this work was to study the immune response in a streptozotocin‐induced type 1 diabetes in two mouse strains: BALB/cByJ and C57Bl/6J. The participation of hyperglycaemia and oxidative stress was also analysed. Diabetic BALB/cByJ mice showed a decrease in both the in‐vivo and in‐vitro immune responses, whereas diabetic C57Bl/6J mice had higher blood glucose but exhibited no impairment of the immune response. The influence of hyperglycaemia over the immune response was evaluated by preincubation of lymphocytes from normal mice in a high glucose‐containing medium. T and B cells from BALB/cByJ mice showed a decrease in cell viability and mitogen‐stimulated proliferation and an increase in apoptosis induction. An increase in oxidative stress was implicated in this deleterious effect. These parameters were not affected in the T and B lymphocytes from C57Bl/6J mice. In conclusion, BALB/cByJ mice were sensitive to the deleterious effect of hyperglycaemia, while C57BL/6J were resistant. Although an extrapolation of these results to clinical conditions must be handled with caution, these results highlight the need to contemplate the genetic background to establish models to study the deleterious effect of diabetes in order to understand phenotypical variations that are of clinical importance in the treatment of patients.     

Echinococcus multilocularis proliferation in mice and respective parasite 14-3-3 gene expression is mainly controlled by an alphabeta CD4 T-cell-mediated immune response

The role of specific B lymphocytes and T-cell populations in the control of experimental Echinococus multilocularis infection was studied in micro MT, nude, T-cell receptor (TCR)-beta(-/-), major histocompatibility complex (MHC)-I(-/-) and MHC-II(-/-) mice. At 2 months postinfection, the parasite mass was more than 10 times higher in nude, TCR-beta(-/-) and MHC-II(-/-) mice than in infected C57BL/6 wild-type (WT) mice, and these T-cell-deficient mice started to die of the high parasite load at this time-point. In contrast, MHC-I(-/-) and micro MT mice exhibited parasite growth rates similar to those found in WT controls. These findings clearly point to the major role that CD4(+) alphabeta(+) T cells play in limiting the E. multilocularis proliferation, while CD8(+) T and B cells appeared to play a minor role in the control of parasite growth. In the absence of T cells, especially CD4(+) or alphabeta(+) T cells, the cellular immune response to infection was impaired, as documented by the lack of hepatic granuloma formation around the parasite and by a decreased splenocyte responsiveness to concanavalin A (Con A) and parasite antigen stimulation. Surprisingly, in T-cell-deficient mice, the ex vivo expression of interferon-gamma (IFN-gamma) and other inflammatory cytokines (except for interleukin-6) were increased in association with a high parasite load. Thus, the relative protection mediated by CD4(+) alphabeta(+) T cells against E. multilocularis infection seemed not be IFN-gamma dependent, but rather to rely on the effector's function of CD4(+) alphabeta(+) T cells. The local restriction of parasite germinal cell proliferation was reflected by a regulatory effect on the expression of 14-3-3 protein within the parasite tissue in T-cell-deficient mice. These results provide a strong indication that the CD4(+) alphabeta(+) T-cell-mediated immune response contributes to the control of the parasite growth and to the regulation of production of the parasite 14-3-3 protein in metacestode tissues.     

Tape strips detect distinct immune and barrier profiles in atopic dermatitis and psoriasis

1. Download : Download high-res image (270KB)
2. Download : Download full-size image