scholarly journals Designing distribution of adjuvants: Synthesis of lipidated nucleic acid adjuvant compounds

2021 ◽  
Author(s):  
◽  
Timothy Bilbrough
Keyword(s):  
Side Effects ◽  
Immune Responses ◽  
Lymph Nodes ◽  
Structural Changes ◽  
Systemic Exposure ◽  
T Cell Response ◽  
Systemic Distribution ◽  
Pharmacokinetic Properties ◽  
Lymph Node Targeting

<p>Peptide vaccines can generate antigen-specific immune responses against tumours. However, peptides on their own are not usually immunogenic and require an adjuvant to ensure antigen-presenting cells are appropriately activated. Adjuvant localisation is essential for its activity; targeting an immunomodulatory compound to the lymph nodes appropriately positions it among a high density of immune cells, where immune responses are coordinated. Furthermore, systemic distribution of a potent immune modulator can lead to severe systemic toxicities. Lymph node targeting reduces systemic exposure with simultaneous reduction of side effects. Where a compound distributes in viva is determined by its pharmacokinetic properties and its route of administration. Once the route has been defined, a drug's pharmacokinetic properties can be modified by structural changes. To this end, we modified existing adjuvants to distribute into the lymphatics preferentially. One method was to increase the hydrophilicity and size of agalactosylceramide to favour lymphatic uptake. The second was to exploit albumin hitchhiking to access the lymph nodes. Here, a-galactosylceramide was chemically linked via an enzyme-labile linker to CpG ODN 1826, a TLR-9 agonist. The properties of each adjuvant mutually alter those of the other: to the CpG, a-galactosylceramide acts as an albumin binding domain; to the a-galactosylceramide, the CpG serves as a large hydrophilic group creating an amphiphile. In vivo, this should activate a strong, multilineage T cell response through the synergy of the two adjuvants. Furthermore, this should reduce the toxicity and side effects of the adjuvant by limiting its systemic distribution. This adjuvant may find further use in vaccines for diseases requiring a Thl response for effective clearance.</p>

scholarly journals Designing distribution of adjuvants: Synthesis of lipidated nucleic acid adjuvant compounds

2021 ◽  
Author(s):  
◽  
Timothy Bilbrough
Keyword(s):  
Side Effects ◽  
Immune Responses ◽  
Lymph Nodes ◽  
Structural Changes ◽  
Systemic Exposure ◽  
T Cell Response ◽  
Systemic Distribution ◽  
Pharmacokinetic Properties ◽  
Lymph Node Targeting

<p>Peptide vaccines can generate antigen-specific immune responses against tumours. However, peptides on their own are not usually immunogenic and require an adjuvant to ensure antigen-presenting cells are appropriately activated. Adjuvant localisation is essential for its activity; targeting an immunomodulatory compound to the lymph nodes appropriately positions it among a high density of immune cells, where immune responses are coordinated. Furthermore, systemic distribution of a potent immune modulator can lead to severe systemic toxicities. Lymph node targeting reduces systemic exposure with simultaneous reduction of side effects. Where a compound distributes in viva is determined by its pharmacokinetic properties and its route of administration. Once the route has been defined, a drug's pharmacokinetic properties can be modified by structural changes. To this end, we modified existing adjuvants to distribute into the lymphatics preferentially. One method was to increase the hydrophilicity and size of agalactosylceramide to favour lymphatic uptake. The second was to exploit albumin hitchhiking to access the lymph nodes. Here, a-galactosylceramide was chemically linked via an enzyme-labile linker to CpG ODN 1826, a TLR-9 agonist. The properties of each adjuvant mutually alter those of the other: to the CpG, a-galactosylceramide acts as an albumin binding domain; to the a-galactosylceramide, the CpG serves as a large hydrophilic group creating an amphiphile. In vivo, this should activate a strong, multilineage T cell response through the synergy of the two adjuvants. Furthermore, this should reduce the toxicity and side effects of the adjuvant by limiting its systemic distribution. This adjuvant may find further use in vaccines for diseases requiring a Thl response for effective clearance.</p>

The design, synthesis, pharmacokinetic and pharmacodynamic evaluation of acyloxyalkyl-substituted T705 prodrugs

2019 ◽  
Vol 15 ◽  
Author(s):  
Xingzhou Li ◽  
Tianhong Zhang ◽  
Wu Zhong
Keyword(s):  
Plasma Concentration ◽  
Development Strategy ◽  
Parent Compound ◽  
Systemic Exposure ◽  
Parent Drug ◽  
New Drugs ◽  
Structure Modification ◽  
Design Synthesis ◽  
Pharmacokinetic Properties

Background: The pharmacokinetic properties of T705 are not optimal for the development of new drugs. Objective: To improve the pharmacokinetic properties of T-705, structure modification of T-705 was conducted using a prodrug strategy. Method: The acidic amide H atom (N4-H) of T705 was attempted to be replaced with acyloxyalkyl groups following the prodrugs development strategy for carboxylic acids, and the resulting compounds were investigated whether could work as prodrugs and contribute to improving the pharmacokinetic properties of the parent compound T705 in vivo. Results: 4-acyloxyalkyl-T705 (4a–e), did act as prodrugs in vivo. 4-iso-butyryloxymethyl-T705 (4a) and 4-acetoxymethyl-T705 (4b) could significantly improve the plasma concentration and systemic exposure for T705, compound 4a displayed non inferior anti-influenza activities, compared with its parent drug T705. Conclusion: Our prodrugs development strategy for T705 is feasible, which may serves as a reference to prodrugs development of similar heterocyclic amides compounds.

Abstract 44: Failure of Protective Autoimmunity in Mouse and Human Atherosclerosis

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Dennis Wolf ◽  
Teresa Gerhardt ◽  
Nathaly Anto Michel ◽  
Bjarke Hansen ◽  
Alessandro Sette ◽  
...  
Keyword(s):  
T Cells ◽  
Lymph Nodes ◽  
Mhc Class Ii ◽  
T Regulatory Cells ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
T Cell Response ◽  
Regulatory Cells ◽  
Protective Autoimmunity

Background: In atherosclerosis, CD4 + T helper cells recognize auto-antigens including ApoB, the main protein in low-density lipoprotein (LDL). However, atherosclerosis-specific, auto-reactive CD4 + T cells have not been detected in vivo , and their function is unknown. Methods and Results: We have previously identified peptides derived from mouse ApoB that bind with high affinity to the MHC class II molecule of C57BL/6 mice (I-A b ). We designed and validated a new multimer of a recombinant MHC-II molecule fused to one ApoB auto-epitopes, P6 (TGAYSNASSTESASY, P6:I-A b ), that enabled detection of low-affinity, P6-reactive CD4 + T cells. Using this P6:I-A b multimer, we identified ApoB-reactive CD4 + T cells in healthy, young C57BL/6 mice that were predominately differentiated T-regulatory cells (T regs ) and expressed IL-10, a known atheroprotective cytokine. This population was detectable in lymph nodes and already showed a memory phenotype in young animals without atherosclerosis. In Apoe -/- mice, adoptively transferred ApoB P6-specific T regs accumulated in the aorta and draining lymph nodes and gave rise to pathogenic T H 1 and T H 17 cells. This phenotypic switch was caused by enhanced plasticity of antigen-specific T regs as evidenced by multiple clusters of intermediate T reg -T eff phenotypes in single cell RNA sequencing of 4485 antigen-specific CD4 + T cells. In the plaque, many T cells were ex-T regs as identified by a FoxP3 lineage tracker mouse, suggesting that atherosclerosis-specific CD4 + T cells lost their regulatory capacity. Vaccination with P6 maintained a protective phenotype in antigen-specific T regs and protected from atherosclerosis. In humans, ApoB-specific CD4 + T cells from atherosclerotic patients showed the same cytokine patterns found in mouse CD4 + T cells, suggesting that autoimmunity to ApoB is protective first, but later gives rise to a pathogenic CD4 + T cell response that aggravates atherosclerosis. Conclusion: Protective T-regulatory cells recognizing peptide antigens of ApoB exist in naïve mice, protect against atherosclerosis, but convert into pathogenic T H 1 and -17 cells during the natural course of disease in mice and humans. These results call for immunomodulatory therapies to maintain protective autoimmunity.

Case Studies Discussing the Pathology, Immunogenicity, and Proposed Mechanism of Toxicity of an Inhaled Anti-TGFβ Humanized Fab Antibody in Non-Human Primates and Mice

2020 ◽  
pp. 019262332096002
Author(s):  
Anthony Peter Hall ◽  
Annick Cauvin ◽  
Sherri Dudal ◽  
James Raymond ◽  
Petrina Rogerson ◽  
...  
Keyword(s):  
Lymph Nodes ◽  
Inflammatory Cell ◽  
Transforming Growth Factor ◽  
Systemic Exposure ◽  
Plasminogen Activator Inhibitor ◽  
Transforming Growth Factor Β ◽  
Lavage Fluid ◽  
T Cell Response ◽  
Plasminogen Activator Inhibitor 1 ◽  
Draining Lymph Nodes

Treatment of nonhuman primates and mice with a humanized antigen-binding fragment (Fab) antibody (UCBFab) inhibiting transforming growth factor β via daily inhalation for up to 13 weeks resulted in low systemic exposure but high local exposure in the lung. Target engagement was demonstrated by reduced levels of signal transducers, phosphoSMAD and plasminogen activator inhibitor-1 in the bronchoalveolar lavage fluid (BALF). Treatment was associated with a high frequency and titer of antidrug antibodies, indicating high local immunogenicity, and local pathology within the lung and draining lymph nodes. Microscopic changes were characterized by perivascular (PV) and peribronchiolar (PB) mononuclear inflammatory cell (MIC) infiltrates that were principally lymphocytic in nature and mixed inflammatory cell infiltrates and/or inflammation within the alveoli. Immunohistochemical investigation revealed a predominantly CD68-positive macrophage and CD3- and CD8>CD4-positive T-cell response in the alveoli, whereas within the airways, there was a variable mixture of CD3-positive T cells, CD20-positive B cells, and CD68-positive macrophages. Increased cellularity of the draining lymph nodes was also noted, indicating the presence of an immune response to the inhaled test article. Morphologic changes did not progress over time, and all changes partially recovered. Increased leukocytes (principally macrophages) in BALF cytology correlated with the changes seen by histopathology.

scholarly journals Immune Responses in Perforin Deficient Mice

2021 ◽  
Author(s):  
◽  
Helen Mary Alys Simkins
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Influenza Infection ◽  
T Cell Responses ◽  
Nkt Cells ◽  
T Cell Response ◽  
Dependent Manner ◽  
Cell Responses

<p>Dendritic cells (DC) play a pivotal role in the initiation of T cell responses and earlier studies have shown that their survival is important for the generation of effective immune responses. Cytotoxic T lymphocytes (CTL) and natural killer T (NKT) cells have been proposed to regulate the survival of antigen presenting DC through their ability to kill cells expressing specific antigen via secretion of perforin, a protein contained in cytotoxic granules. Perforin knockout (PKO) mice generate amplified immune responses to DC immunization, suggesting a link between defective cytotoxicity and increased T cell responses. The studies in this thesis used PKO mice and in vivo models of CD8+T cells and NKT cell immune responses to determine whether CTL and NKT cells eliminate DC in a perforin-dependent manner, and whether DC elimination is a mechanism to regulate T cell responses. During a primary influenza infection C57BL/6 and PKO mice generated a similar influenza specific CD8+ immune response. No significant difference in the percentage of influenza epitope PA224-233 specific T cells was observed between C57BL/6 and PKO mice during a secondary influenza infection, but PKO mice had a significantly reduced T cell response directed towards the dominant influenza epitope, NP366-374. The reduced T cell response in PKO mice was not due to differences in activation or differentiation status of specific T cells compared to C57BL/6 mice. Therefore, the extended DC survival in PKO after secondary influenza viral infection, recently reported by other authors, does not appear to correlate with increased expansion of virus specific CD8+T cells in infected mice. The role of NKT cells in DC elimination was assessed in vivo using the NKT cell ligand a-Galactosylceramide (a-GalCer). Injection of a-GalCer in C57BL/6 mice induced a dramatic decline in the number of splenic CD8+DC. A similar decrease in CD8+DC numbers was observed in PKO mice, suggesting that the mechanism of DC loss did not involve perforinmediated killing. In contrast, treatment with a TNF-a neutralizing antibody substantially reduced the decline in CD8+DC numbers. This reduction in splenic CD8+DC occurred as early as 15 hr after a-GalCer treatment, and did not affect generation of CD8+T cell responses or the ability of a-GalCer treatment to provide tumour protection. Taken together, these results suggest that multiple cells and mechanisms can regulate DC survival in vivo. CTL regulate DC survival in vivo in a perforin-dependent manner, but this does not necessarily affect the magnitude of the resulting immune responses. NKT cells also affect the survival of DC in vivo, but in a perforin-independent, cytokine-dependent manner. These findings provide additional knowledge about the in vivo involvement of perforin in regulating DC survival by CTL and NKT cells and the effects this has on T cell responses.</p>

scholarly journals Immune Responses in Perforin Deficient Mice

2021 ◽  
Author(s):  
◽  
Helen Mary Alys Simkins
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Influenza Infection ◽  
T Cell Responses ◽  
Nkt Cells ◽  
T Cell Response ◽  
Dependent Manner ◽  
Cell Responses

<p>Dendritic cells (DC) play a pivotal role in the initiation of T cell responses and earlier studies have shown that their survival is important for the generation of effective immune responses. Cytotoxic T lymphocytes (CTL) and natural killer T (NKT) cells have been proposed to regulate the survival of antigen presenting DC through their ability to kill cells expressing specific antigen via secretion of perforin, a protein contained in cytotoxic granules. Perforin knockout (PKO) mice generate amplified immune responses to DC immunization, suggesting a link between defective cytotoxicity and increased T cell responses. The studies in this thesis used PKO mice and in vivo models of CD8+T cells and NKT cell immune responses to determine whether CTL and NKT cells eliminate DC in a perforin-dependent manner, and whether DC elimination is a mechanism to regulate T cell responses. During a primary influenza infection C57BL/6 and PKO mice generated a similar influenza specific CD8+ immune response. No significant difference in the percentage of influenza epitope PA224-233 specific T cells was observed between C57BL/6 and PKO mice during a secondary influenza infection, but PKO mice had a significantly reduced T cell response directed towards the dominant influenza epitope, NP366-374. The reduced T cell response in PKO mice was not due to differences in activation or differentiation status of specific T cells compared to C57BL/6 mice. Therefore, the extended DC survival in PKO after secondary influenza viral infection, recently reported by other authors, does not appear to correlate with increased expansion of virus specific CD8+T cells in infected mice. The role of NKT cells in DC elimination was assessed in vivo using the NKT cell ligand a-Galactosylceramide (a-GalCer). Injection of a-GalCer in C57BL/6 mice induced a dramatic decline in the number of splenic CD8+DC. A similar decrease in CD8+DC numbers was observed in PKO mice, suggesting that the mechanism of DC loss did not involve perforinmediated killing. In contrast, treatment with a TNF-a neutralizing antibody substantially reduced the decline in CD8+DC numbers. This reduction in splenic CD8+DC occurred as early as 15 hr after a-GalCer treatment, and did not affect generation of CD8+T cell responses or the ability of a-GalCer treatment to provide tumour protection. Taken together, these results suggest that multiple cells and mechanisms can regulate DC survival in vivo. CTL regulate DC survival in vivo in a perforin-dependent manner, but this does not necessarily affect the magnitude of the resulting immune responses. NKT cells also affect the survival of DC in vivo, but in a perforin-independent, cytokine-dependent manner. These findings provide additional knowledge about the in vivo involvement of perforin in regulating DC survival by CTL and NKT cells and the effects this has on T cell responses.</p>

Identification of CD8α+CD11c− lineage phenotype-negative cells in the spleen as committed precursor of CD8α+ dendritic cells

Blood ◽  
2002 ◽  
Vol 100 (2) ◽  
pp. 569-577 ◽  
Author(s):  
Yong Wang ◽  
Yanyun Zhang ◽  
Hiroyuki Yoneyama ◽  
Nobuyuki Onai ◽  
Taku Sato ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Lymph Nodes ◽  
Messenger Rna ◽  
Critical Role ◽  
Interferon Γ ◽  
T Cell Response ◽  
Interleukin 12 ◽  
Cellular Immune

Abstract CD8α+ dendritic cells (DCs) represent a functionally distinct DC subset in vivo, which plays a critical role in initiating various cellular immune responses. However, the committed precursor of CD8α+ DCs remains to be identified. We reported here that murine splenic CD8α+CD11c− lineage phenotype (Lin)− cells could differentiate into CD8α+DCs in vivo after intravenous transplantation. Immunohistochemistry staining showed that donor-derived DCs mainly located in T-cell areas of the spleen. Functionally, these CD8α+CD11c−Lin− cell–derived DCs were capable of stimulating allogenic T-cell response, as well as secreting bioactive interleukin 12 p70 and interferon γ. Freshly isolated CD8α+CD11c−Lin− cells expressed CC chemokine receptor (CCR)2, CCR5, and CCR7 messenger RNA, whereas CD8α+ DCs derived from CD8α+CD11c−Lin− cells further obtained the expression of CCR6 and macrophage-derived chemokine. Flow cytometry analysis showed that CD8α+CD11c−Lin− cells were identified in bone marrow and lymph nodes. Moreover, transplanted splenic CD8α+CD11c−Lin− cells could also home to thymus and lymph nodes and were capable of developing into CD8α+ DCs in these locations. However, CD8α+CD11c−Lin−cells failed to differentiate into CD8α− DCs, T cells, natural killer cells, or other myeloid lineage cells in irradiated chimeras. Taken together, all these findings suggest that CD8α+CD11c−Lin− cells are a committed precursor of CD8α+ DCs.

The atypical chemokine receptor CCX-CKR scavenges homeostatic chemokines in circulation and tissues and suppresses Th17 responses

Blood ◽  
2010 ◽  
Vol 116 (20) ◽  
pp. 4130-4140 ◽  
Author(s):  
Iain Comerford ◽  
Robert J. B. Nibbs ◽  
Wendel Litchfield ◽  
Mark Bunting ◽  
Yuka Harata-Lee ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Lymph Nodes ◽  
Chemokine Receptor ◽  
Fold Increase ◽  
Wild Type ◽  
Peripheral Lymph ◽  
The Central Nervous System

Abstract Our previous in vitro studies led to proposals that the atypical chemokine receptor CCX-CKR is a scavenger of CCR7 ligand homeostatic chemokines. In the present study, we generated CCX-CKR−/− mice and confirm this scavenger function in vivo. Compared with wild-type mice, CCX-CKR−/− have a 5-fold increase in the level of CCL21 protein in blood, and 2- to 3-fold increases in CCL19 and CCL21 in peripheral lymph nodes. The effect of these protein increases on immunity was investigated after immunization with MOG35-55 peptide emulsified in complete Freund adjuvant (CFA). The subsequent characteristic paralysis develops with enhanced kinetics and severity in CCX-CKR−/− versus wild-type mice. Despite this effect, antigen-specific immune responses in the draining lymph nodes are diminished in CCX-CKR−/− mice. Instead, the earlier onset of disease is associated with enhanced T-cell priming in the CCX-CKR−/− spleen and a skewing of CD4+ T-cell responses toward Th17 rather than Th1. This observation correlates with increased expression of IL-23 in the CCX-CKR−/− spleen and increased CCL21 levels in the central nervous system postimmunization. The early onset of disease in CCX-CKR−/− mice is reversed by systemic administration of neutralizing anti-CCL21 antibodies. Thus, by regulating homeostatic chemokine bioavailability, CCX-CKR influences the localization, kinetics, and nature of adaptive immune responses in vivo.

scholarly journals Investigating Immune Responses to the scAAV9-HEXM Gene Therapy Treatment in Tay–Sachs Disease and Sandhoff Disease Mouse Models

2021 ◽  
Vol 22 (13) ◽  
pp. 6751
Author(s):  
Shalini Kot ◽  
Subha Karumuthil-Melethil ◽  
Evan Woodley ◽  
Violeta Zaric ◽  
Patrick Thompson ◽  
...  
Keyword(s):  
Immune Response ◽  
Gene Transfer ◽  
Immune Responses ◽  
Mouse Models ◽  
Viral Vector ◽  
Sandhoff Disease ◽  
Potential Method ◽  
T Cell Response ◽  
Tay Sachs Disease

GM2 gangliosidosis disorders are a group of neurodegenerative diseases that result from a functional deficiency of the enzyme β-hexosaminidase A (HexA). HexA consists of an α- and β-subunit; a deficiency in either subunit results in Tay–Sachs Disease (TSD) or Sandhoff Disease (SD), respectively. Viral vector gene transfer is viewed as a potential method of treating these diseases. A recently constructed isoenzyme to HexA, called HexM, has the ability to effectively catabolize GM2 gangliosides in vivo. Previous gene transfer studies have revealed that the scAAV9-HEXM treatment can improve survival in the murine SD model. However, it is speculated that this treatment could elicit an immune response to the carrier capsid and “non-self”-expressed transgene. This study was designed to assess the immunocompetence of TSD and SD mice, and test the immune response to the scAAV9-HEXM gene transfer. HexM vector-treated mice developed a significant anti-HexM T cell response and antibody response. This study confirms that TSD and SD mouse models are immunocompetent, and that gene transfer expression can create an immune response in these mice. These mouse models could be utilized for investigating methods of mitigating immune responses to gene transfer-expressed “non-self” proteins, and potentially improve treatment efficacy.

scholarly journals Biocompatible Nanoparticles as a Platform for Enhancing Antitumor Efficacy of Cisplatin–Tetradrine Combination

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Fangcen Liu ◽  
Xinyue Wang ◽  
Qin Liu ◽  
Huan Zhang ◽  
Li Xie ◽  
...  
Keyword(s):  
Side Effects ◽  
Double Emulsion ◽  
Antitumor Efficacy ◽  
In Vivo Studies ◽  
Pet Ct ◽  
Pharmacokinetic Properties ◽  
Metabolic Activities ◽  
Fdg Pet Ct

AbstractCombination therapy has been a standard strategy in the clinical tumor treatment. We have demonstrated that combination of Tetradrine (Tet) and Cisplatin (CDDP) presented a marked synergistic anticancer activity, but inevitable side effects limit their therapeutic concentration. Considering the different physicochemical and pharmacokinetic properties of the two drugs, we loaded them into a nanovehicle together by the improved double emulsion method. The nanoparticles (NPs) were prepared from the mixture of poly(ethyleneglycol)–polycaprolactone (PEG–PCL) and polycarprolactone (HO-PCL), so CDDP and Tet can be located into the NPs simultaneously, resulting in low interfering effect and high stability. Images from fluorescence microscope revealed the cellular uptake of both hydrophilic and hydrophobic agents delivered by the NPs. In vitro studies on different tumor cell lines and tumor tissue revealed increased tumor inhibition and apoptosis rates. As to the in vivo studies, superior antitumor efficacy and reduced side effects were observed in the NPs group. Furthermore, 18FDG-PET/CT imaging demonstrated that NPs reduced metabolic activities of tumors more prominently. Our results suggest that PEG–PCL block copolymeric NPs could be a promising carrier for combined chemotherapy with solid efficacy and minor side effects.

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