Transthyretin-mediated protein and peptide oligomerization for enhanced target clustering

2021 ◽  
Author(s):  
Daniel Yoo ◽  
Kenneth W. Walker
Keyword(s):  
Immune Responses ◽  
Checkpoint Inhibitors ◽  
Disease Research ◽  
Naturally Occurring ◽  
Infectious Disease Research ◽  
Delivery Platform ◽  
Xenograft Models ◽  
Necrosis Factor

Advances in cancer research have led to the development of new therapeutics with significant and durable responses such as immune checkpoint inhibitors. More recent therapies aim to stimulate anti-tumor immune responses by targeting the tumor necrosis factor (TNF) receptors, however this approach has been shown to require clustering of receptors in order to achieve a significant response. Here we present a perspective on using transthyretin, a naturally occurring serum protein, as a drug delivery platform to enable cross-linking independent clustering of targets. TTR forms a stable homo-tetramer with exposed termini that make TTR a highly versatile platform for generating multimeric antibody fusions to enable enhanced target clustering. Fusions with antibodies or Fabs targeting TRAILR2 were shown to have robust cytotoxic activity in vitro and in vivo in colorectal xenograft models demonstrating that TTR is a highly versatile, stable, therapeutic fusion platform that can be used with antibodies, Fabs and other bioactive fusion partners and has broad applications in oncology and infectious disease research.

scholarly journals Lysosomotropic agents including azithromycin, chloroquine and hydroxychloroquine activate the integrated stress response

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ai-Ling Tian ◽  
Qi Wu ◽  
Peng Liu ◽  
Liwei Zhao ◽  
Isabelle Martins ◽  
...  
Keyword(s):  
Stress Response ◽  
Immune Responses ◽  
Initiation Factor ◽  
Integrated Stress Response ◽  
Serine Residue ◽  
Eif2α Phosphorylation ◽  
Lysosomotropic Agents ◽  
Cultured Human Cells

AbstractThe integrated stress response manifests with the phosphorylation of eukaryotic initiation factor 2α (eIF2α) on serine residue 51 and plays a major role in the adaptation of cells to endoplasmic reticulum stress in the initiation of autophagy and in the ignition of immune responses. Here, we report that lysosomotropic agents, including azithromycin, chloroquine, and hydroxychloroquine, can trigger eIF2α phosphorylation in vitro (in cultured human cells) and, as validated for hydroxychloroquine, in vivo (in mice). Cells bearing a non-phosphorylatable eIF2α mutant (S51A) failed to accumulate autophagic puncta in response to azithromycin, chloroquine, and hydroxychloroquine. Conversely, two inhibitors of eIF2α dephosphorylation, nelfinavir and salubrinal, enhanced the induction of such autophagic puncta. Altogether, these results point to the unexpected capacity of azithromycin, chloroquine, and hydroxychloroquine to elicit the integrated stress response.

scholarly journals Conifers Phytochemicals: A Valuable Forest with Therapeutic Potential

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 3005
Author(s):  
Kanchan Bhardwaj ◽  
Ana Sanches Silva ◽  
Maria Atanassova ◽  
Rohit Sharma ◽  
Eugenie Nepovimova ◽  
...  
Keyword(s):  
Experimental Data ◽  
Potential Role ◽  
Therapeutic Potential ◽  
Fungal Infections ◽  
Cell Damage ◽  
Cancer Growth ◽  
Naturally Occurring ◽  
Antioxidant Effects

Conifers have long been recognized for their therapeutic potential in different disorders. Alkaloids, terpenes and polyphenols are the most abundant naturally occurring phytochemicals in these plants. Here, we provide an overview of the phytochemistry and related commercial products obtained from conifers. The pharmacological actions of different phytochemicals present in conifers against bacterial and fungal infections, cancer, diabetes and cardiovascular diseases are also reviewed. Data obtained from experimental and clinical studies performed to date clearly underline that such compounds exert promising antioxidant effects, being able to inhibit cell damage, cancer growth, inflammation and the onset of neurodegenerative diseases. Therefore, an attempt has been made with the intent to highlight the importance of conifer-derived extracts for pharmacological purposes, with the support of relevant in vitro and in vivo experimental data. In short, this review comprehends the information published to date related to conifers’ phytochemicals and illustrates their potential role as drugs.

scholarly journals Survival and Proliferation under Severely Hypoxic Microenvironments Using Cell-Laden Oxygenating Hydrogels

2021 ◽  
Vol 12 (2) ◽  
pp. 30
Author(s):  
Shabir Hassan ◽  
Berivan Cecen ◽  
Ramon Peña-Garcia ◽  
Fernanda Roberta Marciano ◽  
Amir K. Miri ◽  
...  
Keyword(s):  
Prolonged Release ◽  
Therapeutic Approaches ◽  
Encapsulated Cells ◽  
Hypoxic Conditions ◽  
Skeletal Myoblasts ◽  
Artificial Tissue ◽  
Delivery Platform ◽  
Living Tissues

Different strategies have been employed to provide adequate nutrients for engineered living tissues. These have mainly revolved around providing oxygen to alleviate the effects of chronic hypoxia or anoxia that result in necrosis or weak neovascularization, leading to failure of artificial tissue implants and hence poor clinical outcome. While different biomaterials have been used as oxygen generators for in vitro as well as in vivo applications, certain problems have hampered their wide application. Among these are the generation and the rate at which oxygen is produced together with the production of the reaction intermediates in the form of reactive oxygen species (ROS). Both these factors can be detrimental for cell survival and can severely affect the outcome of such studies. Here we present calcium peroxide (CPO) encapsulated in polycaprolactone as oxygen releasing microparticles (OMPs). While CPO releases oxygen upon hydrolysis, PCL encapsulation ensures that hydrolysis takes place slowly, thereby sustaining prolonged release of oxygen without the stress the bulk release can endow on the encapsulated cells. We used gelatin methacryloyl (GelMA) hydrogels containing these OMPs to stimulate survival and proliferation of encapsulated skeletal myoblasts and optimized the OMP concentration for sustained oxygen delivery over more than a week. The oxygen releasing and delivery platform described in this study opens up opportunities for cell-based therapeutic approaches to treat diseases resulting from ischemic conditions and enhance survival of implants under severe hypoxic conditions for successful clinical translation.

scholarly journals A therapeutic vascular conduit to support in vivo cell-secreted therapy

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Edward X. Han ◽  
Hong Qian ◽  
Bo Jiang ◽  
Maria Figetakis ◽  
Natalia Kosyakova ◽  
...  
Keyword(s):  
Vascular Graft ◽  
Large Scale ◽  
Biological Effects ◽  
Therapeutic Protein ◽  
Close Proximity ◽  
Delivery Platform ◽  
Stage Renal Disease ◽  
End Stage

AbstractA significant barrier to implementation of cell-based therapies is providing adequate vascularization to provide oxygen and nutrients. Here we describe an approach for cell transplantation termed the Therapeutic Vascular Conduit (TVC), which uses an acellular vessel as a scaffold for a hydrogel sheath containing cells designed to secrete a therapeutic protein. The TVC can be directly anastomosed as a vascular graft. Modeling supports the concept that the TVC allows oxygenated blood to flow in close proximity to the transplanted cells to prevent hypoxia. As a proof-of-principle study, we used erythropoietin (EPO) as a model therapeutic protein. If implanted as an arteriovenous vascular graft, such a construct could serve a dual role as an EPO delivery platform and hemodialysis access for patients with end-stage renal disease. When implanted into nude rats, TVCs containing EPO-secreting fibroblasts were able to increase serum EPO and hemoglobin levels for up to 4 weeks. However, constitutive EPO expression resulted in macrophage infiltration and luminal obstruction of the TVC, thus limiting longer-term efficacy. Follow-up in vitro studies support the hypothesis that EPO also functions to recruit macrophages. The TVC is a promising approach to cell-based therapeutic delivery that has the potential to overcome the oxygenation barrier to large-scale cellular implantation and could thus be used for a myriad of clinical disorders. However, a complete understanding of the biological effects of the selected therapeutic is absolutely essential.

scholarly journals Application of 3D bioprinting in the prevention and the therapy for human diseases

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Hee-Gyeong Yi ◽  
Hyeonji Kim ◽  
Junyoung Kwon ◽  
Yeong-Jin Choi ◽  
Jinah Jang ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Infectious Diseases ◽  
Rapid Development ◽  
In Vitro Models ◽  
Delivery Systems ◽  
Advanced Technology ◽  
3D Bioprinting ◽  
Disease Research ◽  
Infectious Disease Research

AbstractRapid development of vaccines and therapeutics is necessary to tackle the emergence of new pathogens and infectious diseases. To speed up the drug discovery process, the conventional development pipeline can be retooled by introducing advanced in vitro models as alternatives to conventional infectious disease models and by employing advanced technology for the production of medicine and cell/drug delivery systems. In this regard, layer-by-layer construction with a 3D bioprinting system or other technologies provides a beneficial method for developing highly biomimetic and reliable in vitro models for infectious disease research. In addition, the high flexibility and versatility of 3D bioprinting offer advantages in the effective production of vaccines, therapeutics, and relevant delivery systems. Herein, we discuss the potential of 3D bioprinting technologies for the control of infectious diseases. We also suggest that 3D bioprinting in infectious disease research and drug development could be a significant platform technology for the rapid and automated production of tissue/organ models and medicines in the near future.

scholarly journals Neutrophil subtypes shape HIV-specific CD8 T-cell responses after vaccinia virus infection

npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Mauro Di Pilato ◽  
Miguel Palomino-Segura ◽  
Ernesto Mejías-Pérez ◽  
Carmen E. Gómez ◽  
Andrea Rubio-Ponce ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Vaccinia Virus ◽  
Adaptive Immune System ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cell Responses ◽  
Adaptive Immune

AbstractNeutrophils are innate immune cells involved in the elimination of pathogens and can also induce adaptive immune responses. Nα and Nβ neutrophils have been described with distinct in vitro capacity to generate antigen-specific CD8 T-cell responses. However, how these cell types exert their role in vivo and how manipulation of Nβ/Nα ratio influences vaccine-mediated immune responses are not known. In this study, we find that these neutrophil subtypes show distinct migratory and motility patterns and different ability to interact with CD8 T cells in the spleen following vaccinia virus (VACV) infection. Moreover, after analysis of adhesion, inflammatory, and migration markers, we observe that Nβ neutrophils overexpress the α4β1 integrin compared to Nα. Finally, by inhibiting α4β1 integrin, we increase the Nβ/Nα ratio and enhance CD8 T-cell responses to HIV VACV-delivered antigens. These findings provide significant advancements in the comprehension of neutrophil-based control of adaptive immune system and their relevance in vaccine design.

scholarly journals Reovirus-induced cell-mediated immunity for the treatment of multiple myeloma within the resistant bone marrow niche

2021 ◽  
Vol 9 (3) ◽  
pp. e001803
Author(s):  
Louise M E Müller ◽  
Gemma Migneco ◽  
Gina B Scott ◽  
Jenny Down ◽  
Sancha King ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
T Cells ◽  
Immune Responses ◽  
Stromal Cells ◽  
Tumor Burden ◽  
Effector Memory ◽  
In Vivo Model ◽  
Bm Niche

BackgroundMultiple myeloma (MM) remains an incurable disease and oncolytic viruses offer a well-tolerated addition to the therapeutic arsenal. Oncolytic reovirus has progressed to phase I clinical trials and its direct lytic potential has been extensively studied. However, to date, the role for reovirus-induced immunotherapy against MM, and the impact of the bone marrow (BM) niche, have not been reported.MethodsThis study used human peripheral blood mononuclear cells from healthy donors and in vitro co-culture of MM cells and BM stromal cells to recapitulate the resistant BM niche. Additionally, the 5TGM1-Kalw/RijHSD immunocompetent in vivo model was used to examine reovirus efficacy and characterize reovirus-induced immune responses in the BM and spleen following intravenous administration. Collectively, these in vitro and in vivo models were used to characterize the development of innate and adaptive antimyeloma immunity following reovirus treatment.ResultsUsing the 5TGM1-Kalw/RijHSD immunocompetent in vivo model we have demonstrated that reovirus reduces both MM tumor burden and myeloma-induced bone disease. Furthermore, detailed immune characterization revealed that reovirus: (i) increased natural killer (NK) cell and CD8+ T cell numbers; (ii) activated NK cells and CD8+ T cells and (iii) upregulated effector-memory CD8+ T cells. Moreover, increased effector-memory CD8+ T cells correlated with decreased tumor burden. Next, we explored the potential for reovirus-induced immunotherapy using human co-culture models to mimic the myeloma-supportive BM niche. MM cells co-cultured with BM stromal cells displayed resistance to reovirus-induced oncolysis and bystander cytokine-killing but remained susceptible to killing by reovirus-activated NK cells and MM-specific cytotoxic T lymphocytes.ConclusionThese data highlight the importance of reovirus-induced immunotherapy for targeting MM cells within the BM niche and suggest that combination with agents which boost antitumor immune responses should be a priority.

scholarly journals The BET Inhibitor JQ1 Augments the Antitumor Efficacy of Gemcitabine in Preclinical Models of Pancreatic Cancer

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3470
Author(s):  
Aubrey L. Miller ◽  
Patrick L. Garcia ◽  
Samuel C. Fehling ◽  
Tracy L. Gamblin ◽  
Rebecca B. Vance ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Dna Damage ◽  
Cholesterol Biosynthesis ◽  
Antitumor Efficacy ◽  
Rna Seq ◽  
Bet Inhibitor ◽  
Bet Inhibitors ◽  
Xenograft Models

Gemcitabine is used to treat pancreatic cancer (PC), but is not curative. We sought to determine whether gemcitabine + a BET bromodomain inhibitor was superior to gemcitabine, and identify proteins that may contribute to the efficacy of this combination. This study was based on observations that cell cycle dysregulation and DNA damage augment the efficacy of gemcitabine. BET inhibitors arrest cells in G1 and allow increases in DNA damage, likely due to inhibition of expression of DNA repair proteins Ku80 and RAD51. BET inhibitors (JQ1 or I-BET762) + gemcitabine were synergistic in vitro, in Panc1, MiaPaCa2 and Su86 PC cell lines. JQ1 + gemcitabine was more effective in vivo than either drug alone in patient-derived xenograft models (P < 0.01). Increases in the apoptosis marker cleaved caspase 3 and DNA damage marker γH2AX paralleled antitumor efficacy. Notably, RNA-seq data showed that JQ1 + gemcitabine selectively inhibited HMGCS2 and APOC1 ~6-fold, compared to controls. These proteins contribute to cholesterol biosynthesis and lipid metabolism, and their overexpression supports tumor cell proliferation. IPA data indicated that JQ1 + gemcitabine selectively inhibited the LXR/RXR activation pathway, suggesting the hypothesis that this inhibition may contribute to the observed in vivo efficacy of JQ1 + gemcitabine.

scholarly journals BTK Inhibition Reverses MDSC-Mediated Immunosuppression and Enhances Response to Anti-PDL1 Therapy in Neuroblastoma

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 817
Author(s):  
Mehreen Ishfaq ◽  
Timothy Pham ◽  
Cooper Beaman ◽  
Pablo Tamayo ◽  
Alice L. Yu ◽  
...  
Keyword(s):  
T Cell ◽  
Tumor Growth ◽  
Checkpoint Inhibitors ◽  
No Production ◽  
Free Survival ◽  
T Cell Infiltration ◽  
Car T ◽  
Checkpoint Inhibitor Therapy

MDSCs are immune cells of myeloid lineage that plays a key role in promoting tumor growth. The expansion of MDSCs in tumor-bearing hosts reduces the efficacy of checkpoint inhibitors and CAR-T therapies, and hence strategies that deplete or block the recruitment of MDSCs have shown benefit in improving responses to immunotherapy in various cancers, including NB. Ibrutinib, an irreversible molecular inhibitor of BTK, has been widely studied in B cell malignancies, and recently, this drug is repurposed for the treatment of solid tumors. Herein we report that BTK is highly expressed in both granulocytic and monocytic murine MDSCs isolated from mice bearing NB tumors, and its increased expression correlates with a poor relapse-free survival probability of NB patients. Moreover, in vitro treatment of murine MDSCs with ibrutinib altered NO production, decreased mRNA expression of Ido, Arg, Tgfβ, and displayed defects in T-cell suppression. Consistent with these findings, in vivo inhibition of BTK with ibrutinib resulted in reduced MDSC-mediated immune suppression, increased CD8+ T cell infiltration, decreased tumor growth, and improved response to anti-PDL1 checkpoint inhibitor therapy in a murine model of NB. These results demonstrate that ibrutinib modulates immunosuppressive functions of MDSC and can be used either alone or in combination with immunotherapy for augmenting antitumor immune responses in NB.

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