Abstract 1699: Direct and indirect immune effects of CMP-001, a virus like particle containing a TLR9 agonist

2021 ◽  
Author(s):  
Shakoora Sabree ◽  
Andrew Voigt ◽  
George J. Weiner ◽  
Sue Blackwell
Keyword(s):  
Tlr9 Agonist ◽  
Virus Like Particle

scholarly journals Antibody Opsonization of a TLR9 Agonist–Containing Virus-like Particle Enhances In Situ Immunization

2020 ◽  
Vol 204 (5) ◽  
pp. 1386-1394 ◽  
Author(s):  
Caitlin D. Lemke-Miltner ◽  
Sue E. Blackwell ◽  
Chaobo Yin ◽  
Anna E. Krug ◽  
Aaron J. Morris ◽  
...  
Keyword(s):  
Tlr9 Agonist ◽  
Virus Like Particle

scholarly journals Direct and indirect immune effects of CMP-001, a virus-like particle containing a TLR9 agonist

2021 ◽  
Vol 9 (6) ◽  
pp. e002484
Author(s):  
Shakoora A Sabree ◽  
Andrew P Voigt ◽  
Sue E Blackwell ◽  
Ajaykumar Vishwakarma ◽  
Michael S Chimenti ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cell ◽  
Cell Response ◽  
T Cell Response ◽  
Cd4 T Cell ◽  
T Cell Proliferation ◽  
Secondary Effects ◽  
Tlr9 Agonist ◽  
Virus Like Particle ◽  
Enhanced Expression

BackgroundCMP-001, also known as vidutolimod, is a virus-like particle containing a TLR9 agonist that is showing promise in early clinical trials. Our group previously demonstrated that the immunostimulatory effects of CMP-001 are dependent on an anti-Qβ antibody response which results in opsonization of CMP-001 and uptake by plasmacytoid dendritic cells (pDCs) that then produce interferon (IFN)-α. IFN-α then leads to an antitumor T-cell response that is responsible for the in vivo efficacy of CMP-001. Here, we explore mechanisms by which the initial effects of CMP-001 on pDCs activate other cells that can contribute to development of an antitumor T-cell response.MethodsUptake of CMP-001 by various peripheral blood mononuclear cell (PBMC) populations and response to anti-Qβ-coated CMP-001 were evaluated by flow cytometry and single-cell RNA sequencing. Purified monocytes were treated with anti-Qβ-coated CMP-001 or recombinant IFN-α to evaluate direct and secondary effects of anti-Qβ-coated CMP-001 on monocytes.ResultsMonocytes had the highest per cell uptake of anti-Qβ-coated CMP-001 with lower levels of uptake by pDCs and other cell types. Treatment of PBMCs with anti-Qβ-coated CMP-001 induced upregulation of IFN-responsive genes including CXCL10, PDL1, and indoleamine-2,3-dioxygenase (IDO) expression by monocytes. Most of the impact of anti-Qβ-coated CMP-001 on monocytes was indirect and mediated by IFN-α, but uptake of anti-Qβ-coated CMP-001 altered the monocytic response to IFN-α and resulted in enhanced expression of PDL1, IDO, and CD80 and suppressed expression of CXCL10. These changes included an enhanced ability to induce autologous CD4 T-cell proliferation.ConclusionsAnti-Qβ-coated CMP-001 induces IFN-α production by pDCs which has secondary effects on a variety of cells including monocytes. Uptake of anti-Qβ-coated CMP-001 by monocytes alters their response to IFN-α, resulting in enhanced expression of PDL1, IDO and CD80 and suppressed expression of CXCL10. Despite aspects of an immunosuppressive phenotype, these monocytes demonstrated increased ability to augment autologous CD4 T-cell proliferation. These findings shed light on the complexity of the mechanism of action of anti-Qβ-coated CMP-001 and provide insight into pathways that may be targeted to further enhance the efficacy of this novel approach to immunotherapy.

Immune Electron Microscopy (IEM) of a Canine Adeno-Associated Virus

1974 ◽  
Vol 32 ◽  
pp. 256-257
Author(s):  
Gunter F. Thomas ◽  
M. David Hoggan
Keyword(s):  
Electron Microscopy ◽  
Cell Cultures ◽  
Complement Fixation ◽  
Hepatitis Virus ◽  
Wide Distribution ◽  
Immune Electron Microscopy ◽  
Adeno Associated Virus ◽  
Virus Like Particle ◽  
Dog Kidney ◽  
Green Monkeys

In 1968, Sugimura and Yanagawa described a small 25 nm virus like particle in association with the Matsuda strain of infectious canine hepatitis virus (ICHV). Domoto and Yanagawa showed that this particle was dependent on ICHV for its replication in primary dog kidney cell cultures (PDK) and was resistant to heating at 70°C for 10 min, and concluded that it was a canine adeno-associated virus (CAAV). Later studies by Onuma and Yanagawa compared CAAV with the known human serotypes (AAV 1, 2, 3) and AAV-4, known to be associated with African Green Monkeys. Using the complement fixation (CF) test, they found that CAAV was serologically related to AAV-3 and had wide distribution in the dog population of Japan.

Hepatitis A Antigen in Liver, Bile and Stool

1975 ◽  
Vol 33 ◽  
pp. 340-341
Author(s):  
D.R. Jackson ◽  
J.H. Hoofnagle ◽  
A.N. Schulman ◽  
J.L. Dienstag ◽  
R.H. Purcell ◽  
...  
Keyword(s):  
Hepatitis A ◽  
Liver Enzymes ◽  
Hepatitis A Virus ◽  
Type A ◽  
Initial Study ◽  
Virus Like Particle ◽  
Elevated Liver Enzymes ◽  
Ag Particles ◽  
Ag Particle ◽  
Human Stool

Using immune electron microscopy Feinstone et. al. demonstrated the presence of a 27 nm virus-like particle in acute-phase stools of patients with viral hepatitis, type A, These hepatitis A antigen (HA Ag) particles were aggregated by convalescent serum from patients with type A hepatitis but not by pre-infection serum. Subsequently Dienstag et. al. and Maynard et. al. produced acute hepatitis in chimpanzees by inoculation with human stool containing HA Ag. During the early acute disease, virus like particles antigenically, morphologically and biophysically identical to the human HA Ag particle were found in chimpanzee stool. Recently Hilleman et. al. have described similar particles in liver and serum of marmosets infected with hepatitis A virus (HAV). We have investigated liver, bile and stool from chimpanzees and marmosets experimentally infected with HAV. In an initial study, a chimpanzee (no.785) inoculated with HA Ag-containing stool developed elevated liver enzymes 21 days after exposure.

Using FRET to Measure the Time it Takes for a Cell to Destroy a Virus

2019 ◽  
Author(s):  
Candace E. Benjamin ◽  
Zhuo Chen ◽  
Olivia Brohlin ◽  
Hamilton Lee ◽  
Stefanie Boyd ◽  
...  
Keyword(s):  
Cellular Uptake ◽  
Rhodamine B ◽  
Virus Like Particle ◽  
A Cell ◽  
Viral Nanoparticles ◽  
The Stability ◽  
Open Question ◽  
Viral Surface ◽  
Fret Pair

<div><div><div><p>The emergence of viral nanotechnology over the preceding two decades has created a number of intellectually captivating possible translational applications; however, the in vitro fate of the viral nanoparticles in cells remains an open question. Herein, we investigate the stability and lifetime of virus-like particle (VLP) Qβ - a representative and popular VLP for several applications - following cellular uptake. By exploiting the available functional handles on the viral surface, we have orthogonally installed the known FRET pair, FITC and Rhodamine B, to gain insight of the particle’s behavior in vitro. Based on these data, we believe VLPs undergo aggregation in addition to the anticipated proteolysis within a few hours of cellular uptake.</p></div></div></div>

423 Safety and preliminary efficacy of intratumoral cavrotolimod (AST-008), a spherical nucleic acid TLR9 agonist, in combination with pembrolizumab in patients with advanced solid tumors

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A449-A449
Author(s):  
Steven O’Day ◽  
Cesar Perez ◽  
Trisha Wise-Draper ◽  
Glenn Hanna ◽  
Shailender Bhatia ◽  
...  
Keyword(s):  
Cell Carcinoma ◽  
Solid Tumors ◽  
San Francisco ◽  
Institutional Review Boards ◽  
Advanced Solid Tumors ◽  
Phase 2 ◽  
Serious Adverse Events ◽  
Tlr9 Agonist ◽  
Phase 1B ◽  
Spherical Nucleic Acids

BackgroundSpherical nucleic acids (SNAs) are nanostructures consisting of radially oriented, densely packed oligonucleotides arranged in a spherical 3D architecture. SNAs have different properties than linear oligonucleotides, including increased cellular uptake, which may enhance efficacy. Cavrotolimod (AST-008) is an SNA toll-like receptor 9 (TLR9) agonist designed to robustly activate innate and adaptive immune responses. Cavrotolimod is in development for the treatment of advanced solid tumors in combination with PD-1 blockade. Prior studies demonstrated that cavrotolimod, alone and in combination with PD-1 blockade, increased circulating levels of Th1-type cytokines and activated peripheral T cells and NK cells.MethodsAST-008-102 is an ongoing Phase 1b/2 study (NCT03684785). The Phase 1b dose escalation stage examined intratumoral (IT) cavrotolimod at doses of 2, 4, 8, 16, and 32 mg in combination with pembrolizumab in patients with advanced solid tumors. Cavrotolimod was dosed once weekly for 8 weeks and once every 3 weeks thereafter. The Phase 2 dose expansion stage is examining cavrotolimod 32 mg IT in combination with IV pembrolizumab for the treatment of advanced Merkel cell carcinoma (MCC) and in combination with IV cemiplimab for the treatment of advanced cutaneous squamous cell carcinoma (CSCC). Both cohorts are enrolling patients with documented progression of disease on PD-(L)1 blockade. This analysis provides interim results of the Phase 1b stage.ResultsIn the Phase 1b stage, 20 patients were enrolled across all planned dose levels. No dose-limiting toxicities, grade (G)4 toxicities, or treatment-related serious adverse events (AEs) were observed. The most common AEs were injection site reactions (ISRs) and flu-like symptoms. All treatment-related AEs were < G3 except agitation and ISR (1 each). At data cutoff, ORR is 21% (4 of 19 evaluable patients) in a heterogeneous population with solid tumors. All 4 responders (2 melanoma and 2 MCC patients) have ongoing responses, with duration of response exceeding 52 weeks in 2 patients. Three of 4 responders had disease progression on PD-1 blockade at the time of enrollment, and one patient had a prior response to PD-1 blockade, but subsequently relapsed off therapy. Regression of both injected and noninjected lesions was observed. Gene expression analyses demonstrated increased IT infiltration by cytotoxic immune cells in both injected and noninjected tumors. The highest dose (32 mg) was selected for the Phase 2 stage.ConclusionsIT administration of cavrotolimod appears to be safe and well tolerated in combination with pembrolizumab. Durable responses have occurred in patients previously experiencing progressive disease on PD-1 blockade.Trial RegistrationNCT03684785Ethics ApprovalThe study was approved by Institutional Review Boards of Dana-Farber Cancer Institute (IRB #18-584), John Wayne Cancer Institute (WIRB #20183064), University of Miami (IRB #20180957), University of Iowa (IRB #201810763), University of Cincinnati (WIRB #20183064), University of Washington (WIRB #20183064), MSKCC (IRB #20-174), UC San Francisco (WIRB #20183064), U Colorado (WIRB #20183064), Northwestern (IRB #STU00211083), U Arizona (WIRB #20183064), UC Irvine (WIRB #20183064), U Pitt (WIRB #20183064), and Washington University (WIRB #20183064).

scholarly journals An epitope-based malaria vaccine targeting the junctional region of circumsporozoite protein

npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Lucie Jelínková ◽  
Hugo Jhun ◽  
Allison Eaton ◽  
Nikolai Petrovsky ◽  
Fidel Zavala ◽  
...  
Keyword(s):  
Mouse Model ◽  
Malaria Vaccine ◽  
High Titer ◽  
Circumsporozoite Protein ◽  
Infection Model ◽  
Vaccine Platform ◽  
Junctional Region ◽  
Mouse Infection Model ◽  
Virus Like Particle ◽  
Major Surface

AbstractA malaria vaccine that elicits long-lasting protection and is suitable for use in endemic areas remains urgently needed. Here, we assessed the immunogenicity and prophylactic efficacy of a vaccine targeting a recently described epitope on the major surface antigen on Plasmodium falciparum sporozoites, circumsporozoite protein (CSP). Using a virus-like particle (VLP)-based vaccine platform technology, we developed a vaccine that targets the junctional region between the N-terminal and central repeat regions of CSP. This region is recognized by monoclonal antibodies, including mAb CIS43, that have been shown to potently prevent liver invasion in animal models. We show that CIS43 VLPs elicit high-titer and long-lived anti-CSP antibody responses in mice and is immunogenic in non-human primates. In mice, vaccine immunogenicity was enhanced by using mixed adjuvant formulations. Immunization with CIS43 VLPs conferred partial protection from malaria infection in a mouse model, and passive transfer of serum from immunized macaques also inhibited parasite liver invasion in the mouse infection model. Our findings demonstrate that a Qβ VLP-based vaccine targeting the CIS43 epitope combined with various adjuvants is highly immunogenic in mice and macaques, elicits long-lasting anti-CSP antibodies, and inhibits parasite infection in a mouse model. Thus, the CIS43 VLP vaccine is a promising pre-erythrocytic malaria vaccine candidate.

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