Project description:Introduction: Infiltration of cancers by T-cells is associated with improved patient survival and response to immune therapies; however, optimal approaches to induce T-cell infiltration of tumors are not known. This study tests the hypothesis that topical treatment of melanoma metastases with the TLR7 agonist imiquimod treatment plus administration of a multipeptide cancer vaccine will improve immune cell infiltration of melanoma metastases. Patients and Methods: Eligible patients were immunized with a vaccine comprised of 12 melanoma peptides and a tetanus toxoid-derived helper peptide, and imiquimod was applied topically to tumors daily. Adverse events (AE; CTCAE v4.03) were recorded and effects on the tumor microenvironment (TME) were evaluated from sequential tumor biopsies. T-cell responses were assessed by IFNgamma ELIspot assay, and T-cell tetramer staining. Patient tumors were evaluated for immune cell infiltration, cytokine and chemokine production, and gene expression. Results and Conclusions: Four eligible patients were enrolled, and administration of imiquimod and vaccination was well tolerated in these patients. Circulating T-cell responses to the vaccine were detected by ex vivo ELIspot assay in 3 of 4 patients. Treatment of metastases with imiquimod induced immune cell infiltration and favorable gene signatures in the patients with circulating T-cell responses. This study supports further study of topical imiquimod combined with vaccines or other immune therapies for the treatment of melanoma. Precis: This clinical trial tested topical application of imiquimod to melanoma metastases combined with a melanoma vaccine. The regimen dramatically upregulated immune rejection gene signatures in melanoma metastases and increased T-cell infiltrate.
Project description:The goal of the study is to examine changes in tumor gene expression after imiquimod treatment. RNA was extracted from spontaneous tumors in control mice (n=4) and in imiquimod-treated mice (n=4). Gene expression was compared between the control group and the treated group. In the imiquimod treatment group, the mice received topical treatment of 5% imiquimod cream (Aldara) on shaved skin at the site of spontaneous tumors for one treatment cycle (3 consecutive days). RNA was extracted from 4 spontaneous tumors from neu-tg mice treated with topical imiquimod for 1 cycle and 4 spontaneous tumors from control mice
Project description:To characterize the primary and recall responses to EV71 vaccines, PBMCs from 19 recipients before and after vaccination with EV71 vaccine were collected. 14 samples pre-vaccination and 16 samples post-vaccination were detected by microarray and their gene expression signatures after stimulation with EV71 antigen were compared.
Project description:To characterize the primary and recall responses to EV71 vaccines, PBMC from 19 recipients before and after vaccination with EV71 vaccine are collected and their gene expression signatures after stimulation with EV71 antigen were compared. Four-condition experiment,pre-vaccination PBMCs (stimulation vs. no stimulation with EV71 antigen) vs. post-vaccination PBMCs (stimulation vs. no stimulation with EV71 antigen)
Project description:The goal of the study is to examine changes in tumor gene expression after imiquimod treatment. RNA was extracted from spontaneous tumors in control mice (n=4) and in imiquimod-treated mice (n=4). Gene expression was compared between the control group and the treated group. In the imiquimod treatment group, the mice received topical treatment of 5% imiquimod cream (Aldara) on shaved skin at the site of spontaneous tumors for one treatment cycle (3 consecutive days).
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
Project description:Introduction: Optimal approaches to induce T-cell infiltration of tumors are not known. Chemokines CXCL9, CXCL10, and CXCL11 support effector T-cell recruitment, and may be induced by IFNgamma. This study tests the hypothesis that intratumoral administration of IFNgamma will induce CXCL9-11, and will induce T-cell recruitment and anti-tumor immune signatures in melanoma metastases. Patients and Methods: Nine eligible patients were immunized with a vaccine comprised of 12 class I MHC-restricted melanoma peptides (12MP) and received IFNgamma intratumorally. Effects on the tumor microenvironment (TME) were evaluated in sequential tumor biopsies. Adverse events (AE; CTCAE v4) were recorded. T-cell responses to vaccination were assessed in peripheral blood (PBMC) by IFNgamma ELIspot assay. Tumor biopsies were evaluated for immune cell infiltration, chemokine protein expression and gene expression. Results: Vaccination and intratumoral administration of IFNgamma were well tolerated. Circulating T-cell responses to vaccine were detected in 6 of 9 patients. IFNgamma increased production of chemokines CXCL10, CXCL11, and CCL5 in patient tumors. Neither vaccination alone nor the addition of IFNgamma promoted immune cell infiltration or induced anti-tumor immune gene signatures. Conclusion: The cancer vaccine did not significantly increase T-cell infiltration of tumors. This study provides intriguing findings highlighting some of the limitations of intratumoral IFNgamma treatment. Although IFNgamma is pivotal in anti-tumor immunity, single intratumoral injection may induce secondary immune regulation that paradoxically limits immune infiltration and effector functions. Therefore, alternate dosing strategies or additional combinatorial treatments may be needed to optimally promote trafficking and retention of T-cells in tumor, which merit further study.