A prophylactic effect of an oligodeoxynucleotide containing a cytidine-guanosine motif against Japanese cedar pollen-induced T-helper type 2 allergic response

Nanoparticle-based CpG-oligonucleotide therapy for treating allergic asthma

Allergic asthma is becoming increasingly prevalent in the developed world, and many common allergens are capable of inducing allergic asthma responses, particularly in atopic individuals. Unmethylated CpG-oligonucleotide (ODN) therapy can shift the immune response to mitigate these allergic responses. Therapeutic and prophylactic delivery of soluble CpG-ODN in preclinical studies has shown promise in treating existing asthma and preventing allergic responses upon subsequent allergen exposure, respectively. However, when CpG-ODN is coupled with nanoparticles or self assembled into nanostructures, improved efficacy of CpG-ODN treatment for several common allergens is observed in preclinical studies and clinical trials. Here we discuss the role of CpG-ODN in treating allergic asthma and how nanoparticle-based delivery can further enhance its therapeutic properties.

The effect of the TLR9 ligand CpG-oligodeoxynucleotide on the protective immune response to radiation-induced lung fibrosis in mice

CpG-oligodeoxynucleotide (CpG-ODN) is not only reported to protect against airway hyper responsiveness but is also known as a potent vaccine adjuvant for anti-tumor therapy. Little is known about the effect of CpG-ODN in mice with radiation-induced lung fibrosis (RILF), a common late stage form of tissue damage that occurs after thorax radiotherapy (RT). Here, we evaluated the immunomodulatory effects of CpG-ODN on the development of RILF. Mice were divided into four groups: (1) RT, single dose of 12Gy to the whole thorax; (2) CpG, only intraperitoneal injection of CpG-ODN for total 5 weeks; (3) RT+CpG, irradiation plus CpG-ODN treatment before and after irradiation for total 5 weeks; and (4) control (CTL): No RT or CpG-ODN treatment. In this study, we found that CpG-ODN treatment attenuated lung fibrosis and collagen deposition by increasing the number of M1 macrophagocytes, levels of Type-2 cytokines and TGF-β. CpG-ODN administration up-regulated the expression of TLR9 and STAT1 phosphorylation and reversed the expression of Type-2 immune response key transcription factor GATA-3. Activation of the JAK-STAT1 signaling pathway further enhanced M1 macrophage differentiation and Type-1 cytokine production. This study reveals the mitigating effect of early exposure to CpG-ODN on lung injury caused by irradiation in mice. The potential mechanism of action may be related to enhancement of Type-1 immunity. In conclusion, CpG-ODN may be a potential therapeutic target to treat RILF.

An agonist of human complement fragment C5a enhances vaccine immunity against Coccidioides infection

Coccidioides is a fungal pathogen and causative agent of a human respiratory disease against which no clinical vaccine exists. In this study we evaluated a novel vaccine adjuvant referred to as EP67, which is a peptide agonist of the biologically active C-terminal region of human complement component C5a. The EP67 peptide was conjugated to live spores of an attenuated vaccine strain (ΔT) of Coccidioides posadasii. The non-conjugated ΔT vaccine provided partial protection to BALB/c mice against coccidioidomycosis. In this report we compared the protective efficacy of the ΔT-EP67 conjugate to the ΔT vaccine in BALB/c mice. Animals immunized subcutaneously with the ΔT-EP67 vaccine showed significant increase in survival and decrease in fungal burden over 75 days postchallenge. Increased pulmonary infiltration of dendritic cells and macrophages was observed on day 7 postchallenge but marked decrease in neutrophil numbers had occurred by 11 days. The reduced influx of neutrophils may have contributed to the observed reduction of inflammatory pathology. Mice immunized with the ΔT-EP67 vaccine also revealed enhanced expression of MHC II molecules on the surface of antigen presenting cells, and in vitro recall assays of immune splenocytes showed elevated Th1- and Th17-type cytokine production. The latter correlated with a marked increase in lung infiltration of IFN-γ- and IL-17-producing CD4(+) T cells. Elevated expression of T-bet and RORc transcription factors in ΔT-EP67-vaccinated mice indicated the promotion of Th1 and Th17 cell differentiation. Higher titers of Coccidioides antigen-specific IgG1 and IgG2a were detected in mice immunized with the EP67-conjugated versus the non-conjugated vaccine. These combined results suggest that the EP67 adjuvant enhances protective efficacy of the live vaccine by augmentation of T-cell immunity, especially through Th1- and Th17-mediated responses to Coccidioides infection.