DNA vaccine encoding CD40 targeted to dendritic cells in situ prevents the development of Heymann nephritis in rats

Identification of hub genes and their correlation with immune infiltrating cells in membranous nephropathy: an integrated bioinformatics analysis

BACKGROUND

Membranous nephropathy (MN) is a chronic glomerular disease that leads to nephrotic syndrome in adults. The aim of this study was to identify novel biomarkers and immune-related mechanisms in the progression of MN through an integrated bioinformatics approach.

METHODS

The microarray data were downloaded from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) between MN and normal samples were identified and analyzed by the Gene Ontology analysis, the Kyoto Encyclopedia of Genes and Genomes analysis and the Gene Set Enrichment Analysis (GSEA) enrichment. Hub The hub genes were screened and identified by the weighted gene co-expression network analysis (WGCNA) and the least absolute shrinkage and selection operator (LASSO) algorithm. The receiver operating characteristic (ROC) curves evaluated the diagnostic value of hub genes. The single-sample GSEA analyzed the infiltration degree of several immune cells and their correlation with the hub genes.

RESULTS

We identified a total of 574 DEGs. The enrichment analysis showed that metabolic and immune-related functions and pathways were significantly enriched. Four co-expression modules were obtained using WGCNA. The candidate signature genes were intersected with DEGs and then subjected to the LASSO analysis, obtaining a total of 6 hub genes. The ROC curves indicated that the hub genes were associated with a high diagnostic value. The CD4+ T cells, CD8+ T cells and B cells significantly infiltrated in MN samples and correlated with the hub genes.

CONCLUSIONS

We identified six hub genes (ZYX, CD151, N4BP2L2-IT2, TAPBP, FRAS1 and SCARNA9) as novel biomarkers for MN, providing potential targets for the diagnosis and treatment.

B Cells in Primary Membranous Nephropathy: Escape from Immune Tolerance and Implications for Patient Management

Membranous nephropathy (MN) is an important cause of nephrotic syndrome and chronic kidney disease (CKD) in adults. The pathogenic significance of B cells in MN is increasingly recognized, especially following the discovery of various autoantibodies that target specific podocytic antigens and the promising treatment responses seen with B cell depleting therapies. The presence of autoreactive B cells and autoantibodies that bind to antigens on podocyte surfaces are characteristic features of MN, and are the result of breaches in central and peripheral tolerance of B lymphocytes. These perturbations in B cell tolerance include altered B lymphocyte subsets, dysregulation of genes that govern immunoglobulin production, aberrant somatic hypermutation and co-stimulatory signalling, abnormal expression of B cell-related cytokines, and increased B cell infiltrates and organized tertiary lymphoid structures within the kidneys. An understanding of the role of B cell tolerance and homeostasis may have important implications for patient management in MN, as conventional immunosuppressive treatments and novel B cell-targeted therapies show distinct effects on proliferation, differentiation and reconstitution in different B cell subsets. Circulating B lymphocytes and related cytokines may serve as potential biomarkers for treatment selection, monitoring of therapeutic response and prediction of disease relapse. These recent advances in the understanding of B cell tolerance in MN have provided greater insight into its immunopathogenesis and potential novel strategies for disease monitoring and treatment.

The impact of MDSCs on the efficacy of preventive and therapeutic HIV vaccines

In spite of four decades of research on human immunodeficiency virus (HIV), the virus remains a major health problem, affecting tens of millions of people around the world. As such, developing an effective preventive/protective and therapeutic vaccines against HIV are essential to prevent/limit the continuous spread of the virus as well as to control the disease progression and to completely eradicate the virus from HIV infected patients, respectively. There are several factors that have impeded the development of such vaccines, and we need to gain further insight into these factors in order to enhance our knowledge concerning the proper immune activation pathways in the hope of accelerating the development of the highly sought-after vaccine. Recently, new immune cell populations, namely the myeloid-derived suppressor cells (MDSCs), were added to the battle of HIV infection. Indeed, MDSCs seem to play a central role in determining the efficacy of therapeutic and preventive vaccines, especially because vaccines, in general, enhance immune responses, while as a potent immunosuppressor cell population, MDSCs, in turn, subvert and limit the activation of immune responses. Hence, in this work, we sought to address the role of MDSCs in the context of preventive/protective, as well as, therapeutic HIV vaccines.

Yeasts as a promising delivery platform for DNA and RNA vaccines

Yeasts are considered a useful system for the development of vaccines for human and veterinary health. Species such as Saccharomyces cerevisiae and Pichia pastoris have been used successfully as host organisms for the production of subunit vaccines. These organisms have been also explored as vaccine vehicles enabling the delivery of antigens such as proteins and nucleic acids. The employed species possess a GRAS status (Generally Recognized as Safe) for the production of therapeutic proteins, besides promoting immunostimulation due to the properties of their wall cell composition. This strategy allows the administration of nucleic acids orally and a specific delivery to professional antigen-presenting cells (APCs). In this review, we seek to outline the development of whole yeast vaccines (WYV) carrying nucleic acids in different approaches in the medical field, as well as the immunological aspects of this vaccine strategy. The data presented here reveal the application of this platform in promoting effective immune responses in the context of prophylactic and therapeutic approaches.

CD40/CD40L Signaling as a Promising Therapeutic Target for the Treatment of Renal Disease

The cluster of differentiation 40 (CD40) is activated by the CD40 ligand (CD40L) in a variety of diverse cells types and regulates important processes associated with kidney disease. The CD40/CD40L signaling cascade has been comprehensively studied for its roles in immune functions, whereas the signaling axis involved in local kidney injury has only drawn attention in recent years. Clinical studies have revealed that circulating levels of soluble CD40L (sCD40L) are associated with renal function in the setting of kidney disease. Levels of the circulating CD40 receptor (sCD40), sCD40L, and local CD40 expression are tightly related to renal injury in different types of kidney disease. Additionally, various kidney cell types have been identified as non-professional antigen-presenting cells (APCs) that express CD40 on the cell membrane, which contributes to the interactions between immune cells and local kidney cells during the development of kidney injury. Although the potential for adverse CD40 signaling in kidney cells has been reported in several studies, a summary of those studies focusing on the role of CD40 signaling in the development of kidney disease is lacking. In this review, we describe the outcomes of recent studies and summarize the potential therapeutic methods for kidney disease which target CD40.

Injection of CD40 DNA vaccine ameliorates the autoimmune pathology of non-obese diabetic mice with Sjögren's syndrome

BACKGROUND

Overexpression of CD40 has been reported in patients with primary Sjögren's syndrome (pSS). The increased CD40 expression promote autoimmune response and enhance inflammation in pSS. The aim of this study is to block CD40-CD154 interaction with CD40 DNA vaccine to slow the disease progression of SS in non-obese diabetic (NOD) mice.

METHODS

Female NOD mice were treated with CD40 DNA vaccine, empty vector and normal saline. The salivary flow rate was measured, whereas lymphocytes infiltration in the salivary glands was assessed by histopathology. Expression of CD40 and B220 in salivary were examined by immunohistochemistry. Splenic lymphocyte phenotypes were analyzed by flow cytometry. CD40, IL-1β, TNF-α and IL-6 levels in the salivary glands were detected by PCR. Serum anti-CD40 antibody was measured by ELISA. Serum anti-nuclear antibody (ANA) was monitored by immunofluorescence.

RESULTS

NOD mice treated with CD40 DNA vaccine showed higher levels of anti-CD40 antibody compared with the controls. The expression of CD40 in the salivary glands of NOD mice in CD40 DNA vaccine group was decreased. The infiltration of lymphocytes was reduced in the salivary glands and saliva secretion was increased in the treatment group. The expression level of TNF-α and IL-6 in salivary glands were declined. The splenic dendritic cell and plasma cell populations were reduced and the level of ANA was decreased in NOD mice with CD40 DNA vaccine treatment.

CONCLUSIONS

CD40 DNA vaccine inhibits the immune response and reduce inflammation in epithelial tissues SS in non-obese diabetic (NOD) mice, suggesting that CD40 DNA vaccine could be a new therapeutic approach in treatment of pSS.

DEC205-DC targeted DNA vaccine against CX3CR1 protects against atherogenesis in mice

Studies disrupting the chemokine pathway CX3CL1 (fractalkine)/ CX3CR1 have shown decreased atherosclerosis in animal models but the techniques used to interrupt the pathway have not been easily translatable into human trials. DNA vaccination potentially overcomes the translational difficulties. We evaluated the effect of a DNA vaccine, targeted to CX3CR1, on atherosclerosis in a murine model and examined possible mechanisms of action. DNA vaccination against CX3CR1, enhanced by dendritic cell targeting using DEC-205 single chain variable region fragment (scFv), was performed in 8 week old ApoE-/- mice, fed a normal chow diet. High levels of anti-CX3CR1 antibodies were induced in vaccinated mice. There were no apparent adverse reactions to the vaccine. Arterial vessels of 34 week old mice were examined histologically for atherosclerotic plaque size, macrophage infiltration, smooth muscle cell infiltration and lipid deposition. Vaccinated mice had significantly reduced atherosclerotic plaque in the brachiocephalic artery. There was less macrophage infiltration but no significant change to the macrophage phenotype in the plaques. There was less lipid deposition in the lesions, but there was no effect on smooth muscle cell migration. Targeted DNA vaccination to CX3CR1 was well tolerated, induced a strong immune response and resulted in attenuated atherosclerotic lesions with reduced macrophage infiltration. DNA vaccination against chemokine pathways potentially offers a potential therapeutic option for the treatment of atherosclerosis.

Incorporation of CD40 ligand enhances the immunogenicity of tumor‑associated calcium signal transducer 2 virus‑like particles against lung cancer

The cell surface glycoprotein Trop‑2 is overexpressed in various types of cancer, including in lung cancer, and has recently been used as an effective immunotherapeutic target. CD40 ligand (CD40L), a tumor necrosis factor superfamily member, is a promising immune adjuvant. Human immunodeficiency virus (HIV) gag‑based virus‑like particles (VLPs) are highly immunogenic, and foreign antigens can be incorporated onto their membrane envelope for cancer vaccine development. In the present study, a HIV gag‑based VLP strategy and Bac‑to‑Bac system were utilized to construct Trop‑2, CD40L and gag recombinant baculoviruses, which were then used to infect TN5 cells in order to form Trop‑2 VLPs or Trop‑2‑CD40L VLPs. These VLPs were characterized using transmission electron microscopy and western blot analysis methods. VLPs incorporating murine Trop‑2 only or incorporating Trop‑2 and CD40L were used to immunize C57BL/6 mice. Immunized mice demonstrated high humoral and cellular immunity responses, whereas the Trop‑2‑CD40L VLPs led to higher immune responses in comparison with Trop‑2 only VLPs. Immunization with Trop‑2‑CD40L VLPs also reduced tumor growth more effectively compared with Trop‑2 VLPs. Furthermore, Trop‑2‑CD40L VLP immunization increased the survival rate of Lewis tumor‑bearing mice more significantly when compared with Trop‑2 only VLPs. In conclusion, the present study provided a novel vaccine design by combination of a tumor antigen and an immune adjuvant based on a VLP strategy, which may be potentially applied as an alternative immunotherapeutic option in the treatment of lung cancer.

Enhanced immunity and antiviral effects of an HBV DNA vaccine delivered by a DC-targeting protein

DNA vaccine targeting delivery to DC represents one effective strategy to improve the immunogenicity of the vaccine. In a previous study, we developed a novel DC-targeting recombinant protein that can deliver plasmid DNA to DCs by an electrostatic coupling effect and can thus improve the uptake efficiency of DCs, improving the expression of plasmid DNA in DCs. In this study, we coupled the protein with the HBV DNA vaccine pSVK-HBVA and investigated whether the immunogenicity and antiviral ability of the vaccine can be improved in HBV transgenic mice. The results show that a stronger specific immune response can be induced in mice after immunization with the coupling vaccine. The HBV DNA copy number and circulating antigen HBsAg in the serum of HBV transgenic mice were significantly decreased. Therefore, this study has demonstrated that the DC-targeting protein has the ability to improve the immunogenicity and the antiviral activity of the HBV DNA vaccine pSVK-HBVA. These findings indicate that this DC-targeting protein can be a potential method for the delivery of DNA vaccines directly to DCs.

SiRNA In Vivo-Targeted Delivery to Murine Dendritic Cells by Oral Administration of Recombinant Yeast

SiRNA therapeutics promise a future where any target in the transcriptome could be potentially addressed. However, the delivery of SiRNAs and targeting of particular cell types or organs are major challenges. A novel, efficient, and safe delivery system for promising the introduction of SiRNAs into particular cell types within living organisms is of great significance. Our previous studies have proved that recombinant protein (MSTN) and exogenous gene (EGFP) as vaccines, and furthermore functional CD40 shRNA expression can be delivered into dendritic cells (DCs) in mouse by oral administration of recombinant yeast (Saccharomyces cerevisiae). Here, we describe the details of the promising and innovative approach based on oral administration of recombinant yeast that allows in vivo-targeted delivery of functional SiRNA to murine intestinal DCs.

A novel dendritic-cell-targeting DNA vaccine for hepatitis B induces T cell and humoral immune responses and potentiates the antivirus activity in HBV transgenic mice

Strategies for inducing an effective immune response following vaccination have focused on targeting antigens to dendritic cells (DCs) through the DC-specific surface molecule DEC-205. The immunogenicity and efficacy of DNA vaccination can also be enhanced by fusing the encoded antigen to single-chain antibodies directed against DEC-205. Here, we investigated this promising approach for its enhancement of hepatitis B virus (HBV)-specific cellular and humoral immune responses and its antiviral effects in HBV transgenic mice. A plasmid DNA vaccine encoding mouse DEC-205 single-chain fragment variable (mDEC-205-scFv) linked with the hepatitis B surface antigen (HBsAg) was constructed. Vaccination with this fusion DNA vaccine in HBV transgenic mice induced robust antiviral T cell and antibody immunity against HBsAg. The levels of serum-circulating HBsAg and the HBV DNA copy number were downregulated by the induction of a higher HBsAg-specific response. Thus, in this study, we demonstrated the therapeutic efficacy of the novel mDEC-205-scFv-fused DNA vaccine in a mouse model of immune-tolerant, chronic HBV infection.

Design, expression, and characterization of a novel dendritic cell-targeted proteins

In vivo approaches to inducing an effective immune response focus on targeted antigen (Ag) delivery to dendritic cells (DCs). In this study, we developed a new method of targeting plasmid DNA and/or the antigen (Ag)-antibody (Ab) complex to DCs via the DC receptor DEC-205, also known as cluster of differentiation CD205. We cloned and expressed a recombinant protein composed of mouse DEC-205-specific single-chain fragment variable region (mDEC-205-scFv), the streptococcal protein G (SPG) IgG-binding domain and cationic peptide (CP), which named mDEC205-scFv-SPG-CP (msSC). In vitro, the recombinant protein msSC can specifically bind to DCs through the section of mDEC-205-scFv, and bound the Ag-Ab complex via SPG as well as plasmid DNA through electrostatic bonding with CP in vitro. In addition, msSC functioned in a manner similar to anti-DEC-205 monoclonal Ab and bound to mouse bone marrow-derived DCs. It was demonstrated in vivo that msSC can target plasmid DNA to DCs, resulting in efficient uptake and expression. Moreover, msSC can form a complex with pGL3-CMV and transport it to draining lymph nodes when injected in vivo. These results indicate that msSC can be used as a carrier protein for vaccine delivery to DCs via formation of plasmid DNA-Ag-Ab ternary complexes.

Prophylactic and therapeutic DNA vaccines against Chagas disease

Chagas disease is a zoonosis caused by Trypanosoma cruzi in which the most affected organ is the heart. Conventional chemotherapy has a very low effectiveness; despite recent efforts, there is currently no better or more effective treatment available. DNA vaccines provide a new alternative for both prevention and treatment of a variety of infectious disorders, including Chagas disease. Recombinant DNA technology has allowed some vaccines to be developed using recombinant proteins or virus-like particles capable of inducing both a humoral and cellular specific immune response. This type of immunization has been successfully used in preclinical studies and there are diverse models for viral, bacterial and/or parasitic diseases, allergies, tumors and other diseases. Therefore, several research groups have been given the task of designing a DNA vaccine against experimental infection with T. cruzi. In this review we explain what DNA vaccines are and the most recent studies that have been done to develop them with prophylactic or therapeutic purposes against Chagas disease.

B cell epitope spreading: mechanisms and contribution to autoimmune diseases

While a variety of factors act to trigger or initiate autoimmune diseases, the process of epitope spreading is an important contributor in their development. Epitope spreading is a diversification of the epitopes recognized by the immune system. This process happens to both T and B cells, with this review focusing on B cells. Such spreading can progress among multiple epitopes on a single antigen, or from one antigenic molecule to another. Systemic lupus erythematosus, multiple sclerosis, pemphigus, bullous pemphigoid and other autoimmune diseases, are all influenced by intermolecular and intramolecular B cell epitope spreading. Endocytic processing, antigen presentation, and somatic hypermutation act as molecular mechanisms that assist in driving epitope spreading and broadening the immune response in autoimmune diseases. The purpose of this review is to summarize our current understanding of B cell epitope spreading with regard to autoimmunity, how it contributes during the progression of various autoimmune diseases, and treatment options available.

In vivo targeted delivery of CD40 shRNA to mouse intestinal dendritic cells by oral administration of recombinant Sacchromyces cerevisiae

Short hairpin RNA (shRNA)-mediated gene regulation is a commonly used technique for gene manipulation. An efficient and safe delivery system is indispensable when shRNA is delivered into living organisms for gene therapy. Previous studies have proved that DNA and protein can be delivered into dendritic cells (DCs) by non-pathogenic Saccharomyces cerevisiae without being degraded. CD40 is closely related to apoptosis of tumor cells and some immune mechanisms. In this study, we demonstrated that recombinant yeast S. cerevisiae efficiently delivered the shRNA of immune-associated gene (CD40) into mouse intestinal DCs via oral administration. Western blot analysis of isolated intestinal DCs indicated that the inhibition of CD40 gene expression reached up to 56-91%. The secretion of cytokines such as interleukin-2 (IL-2), IL-6, IL-10, IL-12, tumor necrosis factor-α and interferon-γ in intestinal DCs had varying degrees of changes. In conclusion, we found that orally administered recombinant yeast can be used as an efficient shRNA delivery system for intestinal DC-specific gene silencing and immunomodulation in vivo.

DNA vaccination as a treatment for chronic kidney disease

Chronic kidney disease is one of the major health problems worldwide. DNA vaccination delivers plasmid DNA encoding the target gene to induce both humoral and cellular immune responses. Here, we describe the methods of CD40 DNA vaccine enhanced by dendritic cell (DC) targeting on the development of Heymann nephritis (HN), a rat model of human membranous nephropathy.