scholarly journals Comparison of a Regulated Delayed Antigen Synthesis System withIn Vivo-Inducible Promoters for Antigen Delivery by Live AttenuatedSalmonellaVaccines

2010 ◽  
Vol 79 (2) ◽  
pp. 937-949 ◽  
Author(s):  
Shifeng Wang ◽  
Yuhua Li ◽  
Huoying Shi ◽  
Wei Sun ◽  
Kenneth L. Roland ◽  
...  
Keyword(s):  
Gene Expression ◽  
Immune Responses ◽  
Lymphoid Tissues ◽  
Host Immune System ◽  
Antigen Delivery ◽  
Synthesis System ◽  
Inducible Promoters ◽  
Antigen Gene ◽  
High Level

ABSTRACTInduction of strong immune responses against a vectored antigen in hosts immunized with live attenuatedSalmonellavaccines is related in part to the amount of antigen delivered and the overall fitness of theSalmonellavector in relation to its ability to stimulate the host immune system. Constitutive high-level antigen synthesis causes a metabolic burden to the vaccine vector strain that can reduce the vaccine strain's ability to interact with host lymphoid tissues, resulting in a compromised immune response. A solution to this problem is the use of systems that regulate antigen gene expression, permitting high levels of antigen synthesis only after the vaccine strain has reached its target tissues.In vivo-inducible promoters (IVIPs) are often used to accomplish this. We recently developed an alternative strategy, a regulated delayed antigen synthesis (RDAS) system, in which the LacI-repressible Ptrcpromoter controls antigen gene expression by adding arabinose. In this paper, we compared the RDAS system with two commonly used IVIPs, PssaGand PpagC. Three nearly identical plasmids, differing only in the promoter used to direct transcription of the pneumococcalpspAgene, Ptrc, PssaG, or PpagC, were constructed and introduced into isogenicSalmonellavaccine strains with or without arabinose-inducible LacI synthesis. Mice immunized with the RDAS strain developed slightly higher titers of mucosal and serum anti-PspA antibodies than PpagC-immunized mice, while titers in mice immunized with the PssaGstrain were 100-fold lower. Both the RDAS and PpagCstrains conferred similar levels of protection againstStreptococcus pneumoniaechallenge, significantly greater than those for the PssaGstrain or controls. Thus, RDAS provides another choice for inclusion in the live vaccine design to increase immunogenicity.

scholarly journals In vivo monitoring of transfected DNA, gene expression kinetics, and cellular immune responses in mice immunized with a human NIS gene-expressing plasmid

2016 ◽  
Vol 29 (4) ◽  
pp. 612-625 ◽  
Author(s):  
Hye-Youn Son ◽  
Yong-Hyun Jeon ◽  
June-Key Chung ◽  
Chul-Woo Kim
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Immune Responses ◽  
Whole Body ◽  
Lymphoid Tissues ◽  
Sequential Presentation ◽  
Sodium Iodide Symporter ◽  
Systemic Injection ◽  
Nis Gene

In assessing the effectiveness of DNA vaccines, it is important to monitor: (1) the kinetics of target gene expression in vivo; and (2) the movement of cells that become transfected with the plasmid DNA used in the immunization of a subject. In this study, we used, as a visual imaging marker, expression of the transfected human sodium/iodide symporter ( hNIS) gene, which enhances intracellular radio-pertechnetate (TcO4–) accumulation. After intradermal (i.d.) and systemic injection of mice with pcDNA-hNIS and radioactive Technetium-99m (Tc-99m), respectively, whole-body images were obtained by nuclear scintigraphy. The migration of mice cells transfected with the hNIS gene was monitored over a 2-week period by gamma-radioactivity counting of isolated cell populations and was demonstrated in peripheral lymphoid tissues, especially in the draining lymph nodes (dLNs). Beginning at 24 h after DNA inoculation and continuing for the 2-week monitoring period, hNIS-expressing cells were observed specifically in the T-cell–rich zones of the paracortical area of the dLNs. Over the same time period, high levels of INF-γ–secreting CD8 T-cells were found in the dLNs of the pcDNA-hNIS immunized mice. Tumor growth was also significantly retarded in the mice that received hNIS DNA immunization followed by inoculation with CT26 colorectal adenocarcinoma cells that had been transfected with the rat NIS gene ( rNIS), which is 93% homologous to the hNIS gene. In conclusion, mouse cells transfected with hNIS DNA after i.d. immunization were found to traffic to the dLNs, and hNIS gene expression in these cells continued for at least 2 weeks post immunization. Furthermore, sequential presentation of NIS DNA to T-cells by migratory antigen presenting cells could induce NIS DNA-specific Th1 immune responses and thus retard the growth of NIS-expressing tumors.

scholarly journals Protective Response in Experimental Paracoccidioidomycosis Elicited by Extracellular Vesicles Containing Antigens of Paracoccidioides brasiliensis

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1813
Author(s):  
Ludmila Matos Baltazar ◽  
Gabriela Fior Ribeiro ◽  
Gustavo J. Freitas ◽  
Celso Martins Queiroz-Junior ◽  
Caio Tavares Fagundes ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Treatment Effectiveness ◽  
Ex Vivo ◽  
Paracoccidioides Brasiliensis ◽  
Systemic Disease ◽  
Host Immune System ◽  
Antigen Delivery ◽  
Activated T Lymphocytes ◽  
Cell Mobilization

Paracoccidioidomycosis (PCM) is a systemic disease caused by Paracoccidioides spp. PCM is endemic in Latin America and most cases are registered in Brazil. This mycosis affects mainly the lungs, but can also spread to other tissues and organs, including the liver. Several approaches have been investigated to improve treatment effectiveness and protection against the disease. Extracellular vesicles (EVs) are good antigen delivery vehicles. The present work aims to investigate the use of EVs derived from Paracoccidioides brasiliensis as an immunization tool in a murine model of PCM. For this, male C57BL/6 were immunized with two doses of EVs plus adjuvant and then infected with P. brasiliensis. EV immunization induced IgM and IgG in vivo and cytokine production by splenocytes ex vivo. Further, immunization with EVs had a positive effect on mice infected with P. brasiliensis, as it induced activated T lymphocytes and NKT cell mobilization to the infected lungs, improved production of proinflammatory cytokines and the histopathological profile, and reduced fungal burden. Therefore, the present study shows a new role for P. brasiliensis EVs in the presence of adjuvant as modulators of the host immune system, suggesting their utility as immunizing agents.

scholarly journals The CD11b promoter directs high-level expression of reporter genes in macrophages in transgenic mice [published erratum appears in Blood 1995 Apr 1;85(7):1983]

Blood ◽  
1995 ◽  
Vol 85 (2) ◽  
pp. 319-329 ◽  
Author(s):  
S Dziennis ◽  
RA Van Etten ◽  
HL Pahl ◽  
DL Morris ◽  
TL Rothstein ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transgenic Mice ◽  
Transgene Expression ◽  
Heterologous Gene Expression ◽  
Myeloid Cells ◽  
Reporter Genes ◽  
Regulatory Elements ◽  
Specific Expression ◽  
High Level

Abstract CD11b is the alpha chain of the Mac-1 integrin and is preferentially expressed in myeloid cells (neutrophils, monocytes, and macrophages). We have previously shown that the CD11b promoter directs cell-type- specific expression in myeloid lines using transient transfection assays. To confirm that these promoter sequences contain the proper regulatory elements for correct myeloid expression of CD11b in vivo, we have used the -1.7-kb human CD11b promoter to direct reporter gene expression in transgenic mice. Stable founder lines were generated with two different reporter genes, a Thy 1.1 surface marker and the Escherichia coli lacZ (beta-galactosidase) gene. Analysis of founders generated with each reporter demonstrated that the CD11b promoter was capable of driving high levels of transgene expression in murine macrophages for the lifetime of the animals. Similar to the endogenous gene, transgene expression was preferentially found in mature monocytes, macrophages, and neutrophils and not in myeloid precursors. These experiments indicate that the -1.7 CD11b promoter contains the regulatory elements sufficient for high-level macrophage expression. This promoter should be useful for targeting heterologous gene expression to mature myeloid cells.

scholarly journals Lymphocyte Homing to Bronchus-associated Lymphoid Tissue (BALT) Is Mediated by L-selectin/PNAd, α4β1 Integrin/VCAM-1, and LFA-1 Adhesion Pathways

2003 ◽  
Vol 197 (10) ◽  
pp. 1255-1267 ◽  
Author(s):  
Baohui Xu ◽  
Norbert Wagner ◽  
Linh Nguyen Pham ◽  
Vincent Magno ◽  
Zhongyan Shan ◽  
...  
Keyword(s):  
Immune Responses ◽  
Lymphoid Tissue ◽  
Lymphoid Tissues ◽  
Lymphocyte Migration ◽  
High Endothelial Venules ◽  
Level Of Involvement ◽  
Selectin Ligand ◽  
High Level ◽  
Migration Pathways ◽  
B And T Lymphocytes

Bronchus-associated lymphoid tissue (BALT) participates in airway immune responses. However, little is known about the lymphocyte–endothelial adhesion cascades that recruit lymphocytes from blood into BALT. We show that high endothelial venules (HEVs) in BALT express substantial levels of VCAM-1, in marked contrast to HEVs in other secondary lymphoid tissues. BALT HEVs also express the L-selectin ligand PNAd. Anti–L-selectin, anti-PNAd, and anti–LFA-1 mAbs almost completely block the homing of B and T lymphocytes into BALT, whereas anti–α4 integrin and anti–VCAM-1 mAbs inhibit homing by nearly 40%. α4β7 integrin and MAdCAM-1 are not involved. Importantly, we found that mAbs against α4 integrin and VCAM-1 significantly block the migration of total T cells (80% memory phenotype) but not naive T and B cells to BALT. These results suggest that an adhesion cascade, which includes L-selectin/PNAd, α4β1 integrin/VCAM-1, and LFA-1, targets specific lymphocyte subsets to BALT. This high level of involvement of α4β1 integrin/VCAM-1 is unique among secondary lymphoid tissues, and may help unify lymphocyte migration pathways and immune responses in BALT and other bronchopulmonary tissues.

scholarly journals A Novel Recombinant Fcγ Receptor-Targeted Survivin Combines with Chemotherapy for Efficient Cancer Treatment

Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 806
Author(s):  
Chiao-Chieh Wu ◽  
Chen-Yi Chiang ◽  
Shih-Jen Liu ◽  
Hsin-Wei Chen
Keyword(s):  
Immune Responses ◽  
Fusion Protein ◽  
Human Cancer ◽  
Formyl Peptide Receptor ◽  
Antigen Delivery ◽  
Potential Candidate ◽  
Fcγ Receptor ◽  
Formyl Peptide ◽  
Efficient Uptake

Formyl peptide receptor-like 1 inhibitor (FLIPr), an Fcγ receptor (FcγR) antagonist, can be used as a carrier to guide antigen-FLIPr fusion protein to FcγR then enhances antigen-specific immune responses. Survivin, a tumor-associated antigen, is over-expressed in various types of human cancer. In this study, we demonstrate that recombinant survivin-FLIPr fusion protein (rSur-FLIPr) binds to FcγRs, and efficient uptake by dendritic cells in vivo. In addition, rSur-FLIPr alone stimulates survivin-specific immune responses, which effectively suppresses the tumor growth. The antitumor immunities are through TAP-mediated and CD8-dependent pathways. Furthermore, preexisting anti-FLIPr antibody does not abolish antitumor responses induced by rSur-FLIPr immunization. These results suggest that FLIPr is an effective antigen delivery vector and can be repeatedly used. Combination of chemotherapy with rSur-FLIPr treatment reveals a great benefit to tumor-bearing mice. Altogether, these findings suggest that rSur-FLIPr is a potential candidate for efficient cancer therapy.

Cell-Penetrating Peptide-Mediated Nanovaccine Delivery

2021 ◽  
Vol 22 ◽  
Author(s):  
Jizong Jiang
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Cell Penetrating Peptide ◽  
Antigen Delivery ◽  
Efficient Manner ◽  
Antigen Uptake ◽  
Cell Penetrating ◽  
The Stability ◽  
Antigen Presenting

Abstract: Vaccination with small antigens, such as proteins, peptides, or nucleic acids, is used to activate the immune system and trigger the protective immune responses against a pathogen. Currently, nanovaccines are undergoing development instead of conventional vaccines. The size of nanovaccines is in the range of 10–500 nm, which enables them to be readily taken up by cells and exhibit improved safety profiles. However, low-level immune responses, as the removal of redundant pathogens, trigger counter-effective activation of the immune system invalidly and present a challenging obstacle to antigen recognition and its uptake via antigen-presenting cells (APCs). In addition, toxicity can be substantial. To overcome these problems, a variety of cell-penetrating peptide (CPP)-mediated vaccine delivery systems based on nanotechnology have been proposed, most of which are designed to improve the stability of antigens in vivo and their delivery into immune cells. CPPs are particularly attractive components of antigen delivery. Thus, the unique translocation property of CPPs ensures that they remain an attractive carrier with the capacity to deliver cargo in an efficient manner for the application of drugs, gene transfer, protein, and DNA/RNA vaccination delivery. CPP-mediated nanovaccines can enhance antigen uptake, processing, and presentation by APCs, which are the fundamental steps in initiating an immune response. This review describes the different types of CPP-based nanovaccines delivery strategies.

scholarly journals HOXA9 is required for survival in human MLL-rearranged acute leukemias

Blood ◽  
2009 ◽  
Vol 113 (11) ◽  
pp. 2375-2385 ◽  
Author(s):  
Joerg Faber ◽  
Andrei V. Krivtsov ◽  
Matthew C. Stubbs ◽  
Renee Wright ◽  
Tina N. Davis ◽  
...  
Keyword(s):  
Gene Expression ◽  
Expression Profiling ◽  
Therapeutic Option ◽  
Mixed Lineage Leukemia ◽  
High Level Expression ◽  
Acute Leukemias ◽  
Gene Expression Analyses ◽  
High Level ◽  
Novel Therapeutic

Leukemias that harbor translocations involving the mixed lineage leukemia gene (MLL) possess unique biologic characteristics and often have an unfavorable prognosis. Gene expression analyses demonstrate a distinct profile for MLL-rearranged leukemias with consistent high-level expression of select Homeobox genes, including HOXA9. Here, we investigated the effects of HOXA9 suppression in MLL-rearranged and MLL-germline leukemias using RNA interference. Gene expression profiling after HOXA9 suppression demonstrated co–down-regulation of a program highly expressed in human MLL-AML and murine MLL-leukemia stem cells, including HOXA10, MEIS1, PBX3, and MEF2C. We demonstrate that HOXA9 depletion in 17 human AML/ALL cell lines (7 MLL-rearranged, 10 MLL-germline) induces proliferation arrest and apoptosis specifically in MLL-rearranged cells (P = .007). Similarly, assessment of primary AMLs demonstrated that HOXA9 suppression induces apoptosis to a greater extent in MLL-rearranged samples (P = .01). Moreover, mice transplanted with HOXA9-depleted t(4;11) SEMK2 cells revealed a significantly lower leukemia burden, thus identifying a role for HOXA9 in leukemia survival in vivo. Our data indicate an important role for HOXA9 in human MLL-rearranged leukemias and suggest that targeting HOXA9 or downstream programs may be a novel therapeutic option.

Therapeutic Antimyeloma Effect of Dendritic-Tumor Cells Hybrids Transduced with Adenovirus Encoding CD40L.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1709-1709
Author(s):  
Eva Alvarez ◽  
Esther Moga ◽  
Jorge Sierra ◽  
Javier Briones
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Tumor Cells ◽  
Antitumor Effect ◽  
Tumor Antigens ◽  
Recombinant Adenovirus ◽  
Lymphoid Tissues ◽  
Term Survival ◽  
Mhc Ii

Abstract Dendritic cells (DCs) are the main antigen presenting cells and play a pivotal role in the stimulation of T-cell immune responses. DCs cultured in the presence of a single tumor antigen can elicit an immune response against tumor cells expressing that antigen. However, simultaneous use of several tumor antigens may be advantageous since polyclonal activation of T cells against different tumor antigens may be a better approach to eradicate tumor cells. In this sense, fusions of dendritic and tumor cells (FCs) show a broad spectrum of tumor antigens, both known and unidentified, to be presented by class I and II MHC. Although prophylactic vaccines were successful in murine models, the results in the therapeutic setting have been unsatisfactory. We hypothesised that enhancing costimulation of FCs would help to break tumor tolerance once the tumor is established. To this purpose, we transduced FCs with a recombinant adenovirus encoding CD40L (AdvCD40L or AdvGFP as control) and we studied the therapeutic antitumoral effect of the administration of FC-CD40L in a murine model of myeloma. DCs obtained from day 7-bone marrow cultures of Balb/c mice were fused with tumor cells, a syngeneic murine myeloma cell line (4TOO). FCs hybrids were generated with PEG and selected after culturing in HAT medium plus GM-CSF for 7 days. FC were quantified by determining the percentage of cells that coexpress specific DC (CD11c) and tumor markers (CD138). Mean fusion efficiency was 30% (20–40%) and FCs expressed moderate levels of CD80, CD83, CD86, CD54, CD40 and MHC II and did not express CD40L. FC-CD40L showed a significant increase of expression of costimulatory molecules (CD80, CD86, CD54, and MHC II) compared to FC-GFP (p=0.011). Moreover, in a syngeneic mixed lymphocyte reaction, FC-CD40L induced a two-fold higher T-cell proliferation than FC-GFP or FC alone. In addition, FC-CD40L had improved migration to lymphoid tissues, preferentially to spleen, in comparison with FC-GFP (2.8% versus 1.6%). The antitumor effect of FC-CD40L was analyzed in vivo. Mice (n=10 per group) were injected i.v. with 2.5×105 tumor cells and treated with irradiated FC, FC-GFP or FC-CD40L (1×106 cells each) on days 2, 6 and 10 after tumor challenge. 40% of mice treated with FC-CD40L had long-term survival (>120 days). In contrast, all of mice treated with FC or FC-GFP died between days 25 and 35 (p=0.012). In parallel, treatment with mixed cells (not fused DC+ tumor cells), mix transduced with AdvGFP, or mix transduced with AdvCD40L did not provide any significant antitumor effect. We conclude that FCs transduced with AdvCD40L better stimulate in vitro and in vivo immune responses than FC alone and may provide a new strategy for treating patients with multiple myeloma or lymphoma.

scholarly journals Antigen Delivery to CD11c+CD8− Dendritic Cells Induces Protective Immune Responses against Experimental Melanoma in Mice In Vivo

2014 ◽  
Vol 192 (12) ◽  
pp. 5830-5838 ◽  
Author(s):  
Kirsten Neubert ◽  
Christian H. K. Lehmann ◽  
Lukas Heger ◽  
Anna Baranska ◽  
Anna Maria Staedtler ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Immune Responses ◽  
Antigen Delivery

Guanidinylated cationic nanoparticles as robust protein antigen delivery systems and adjuvants for promoting antigen-specific immune responses in vivo

2016 ◽  
Vol 4 (33) ◽  
pp. 5608-5620 ◽  
Author(s):  
Pan Li ◽  
Gaona Shi ◽  
Xiuyuan Zhang ◽  
Huijuan Song ◽  
Chuangnian Zhang ◽  
...  
Keyword(s):  
Immune Responses ◽  
Delivery Systems ◽  
Protein Antigen ◽  
Antigen Delivery ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Immune Adjuvants ◽  
Cationic Nanoparticles ◽  
Antigen Delivery Systems

Guanidinylated nanoparticles could act as effective immune adjuvants to elicit both potent antigen-specific cellular and humoral immune responses.

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