Project description:This study explores the safety and efficacy of combining topical Imiquimod (IMQ), a TLR-7 agonist, with local radiotherapy (RT) for metastatic breast cancer. The phase I/II clinical trial (NCT01421017) aimed to assess systemic and local anti-tumor responses using immune-related response criteria (irRC). Patients were divided into three cohorts: (1) IMQ + RT + cyclophosphamide, (2) IMQ + RT, and (3) RT + cyclophosphamide (control). Cutaneous metastases were treated with IMQ+RT (area A) or IMQ alone (area B). Tumor biopsies were obtained at baseline and after treatment for gene expression profiling. Results demonstrated safety and promising systemic anti-tumor responses, with transcriptional analyses revealing a T-helper 1 immune orientation and DNA-repair gene downregulation associated with complete responses in IMQ+RT-treated areas.
Project description:The purpose of this experiment was to assess the genes upregulated when pDCs were stimulated with TLR7 agonist imiquimod and TLR9 agonist CpG C.
Project description:The purpose of this experiment was to assess the genes upregulated when pDCs were stimulated with TLR7 agonist imiquimod and TLR9 agonist CpG C. pDCs were isolated from six healthy donors by FACS sorting, and were stimulated with CpG and imiquimod for 18 hours, after which RNA was extracted for next generation sequencing on the Illumina HiSeq platform. Unstimulated samples were included as controls.
Project description:Goal was to detect differences in response to TLR7 versus TLR8 agonists in human monocytes from healthy donors 3 deidentified donors from the Red Cross, monocytes from each donor incubated overnight with either vehicle, TLR7 agonist or TLR8 agonist
Project description:Treatment with the TLR7/8 agonist R848 results in a significant increase in classic dendritic cells (DCs) in the bone marrow, but a decrease in common dendritic cell progenitors and pre-DCs. Phenotypic analysis of DCs showed that R848 treatment is associated with altered expression of certain chemokines, activation markers, and migratory receptors.
Project description:UNC93B1 is critical for trafficking and function of nucleic acid-sensing Toll-like receptors (TLRs) TLR3, TLR7, TLR8, and TLR9, which are essential for antiviral immunity. Overactive TLR7 signaling induced by recognition of self-nucleic acids has been implicated in systemic lupus erythematosus (SLE). Here, we report UNC93B1 variants (E92G and R336L) in four patients with early-onset SLE. Patient cells or mouse macrophages carrying the UNC93B1 variants produced high amounts of TNF-α and IL-6 and upon stimulation with TLR7/TLR8 agonist, but not with TLR3 or TLR9 agonists. E92G causes UNC93B1 protein instability and reduced interaction with TLR7, leading to selective TLR7 hyperactivation with constitutive type I IFN signaling. Thus, UNC93B1 regulates TLR subtype-specific mechanisms of ligand recognition. Our findings establish a pivotal role for UNC93B1 in TLR7-dependent autoimmunity and highlight the therapeutic potential of targeting TLR7 in SLE.
Project description:Plasmacytoid dendritic cells (pDCs) can be activated by the endosomal TLRs, and contribute to the pathogenesis of systemic lupus erythematosus (SLE) by producing type I IFNs. Thus, blocking TLR-mediated pDC activation may represent a useful approach for the treatment of SLE. In an attempt to identify a therapeutic target for blocking TLR signaling in pDCs, we investigated the contribution of Bruton's tyrosine kinase (Btk) to the activation of pDCs by TLR7 and TLR9 stimulation by using a selective Btk inhibitor RN486. Stimulation of TLR7 and 9 with their respective agonist, namely, gardiquimod and type A CpG ODN2216, resulted in the activation of human pDCs, as demonstrated by the expression of activation markers (CD69, CD40, and CD86), elevated production of IFN-alpha and other inflammatory cytokines, as well as up-regulation of numerous genes including IFN-alpha-inducible genes and activation of interferon regulatory factor 7 (IRF7) and NF-kB. RN486 inhibited all of these events induced by TLR9, but not TLR7 stimulation, with a nanomolar potency for inhibiting type A CpG ODN2216-mediated production of cytokines (e.g., IC50=386 nM for inhibiting IFN-alpha). Our data reveal Btk as an important regulatory enzyme in the TLR9 pathway, and a potential therapeutic target for SLE and other TLR-driven diseases. pDCs from healthy donors (n=4) were treated with gardiquimod (TLR7 agonist) or ODN 2216 (TLR9 agonist) with or without BTK inhibitor for 3 hours.
Project description:Class-switching to IgG2a/c in mice is a hallmark response to intracellular pathogens. T cells can promote class-switching and the predominant pathway for induction of IgG2a/c antibody responses has been suggested to be via stimulation from Th1 cells. We previously formulated CAF®01 (cationic liposomes containing dimethyldioctadecylammonium bromide (DDA) and Trehalose-6,6-dibehenate (TDB)) with the lipidated TLR7/8 agonist 3M-052 (DDA/TDB/3M-052), which promoted robust Th1 immunity in newborn mice. When testing this adjuvant in adult mice using the recombinant Chlamydia trachomatis (C.t.) vaccine antigen CTH522, it similarly enhanced IgG2a/c responses compared to DDA/TDB, but surprisingly reduced the magnitude of the IFN-g+ Th1 response in a TLR7 agonist dose-dependent manner. Single cell RNA-sequencing revealed that DDA/TDB/3M-052 liposomes initiated early transcription of class-switch regulating genes directly in pre-germinal center B cells. Mixed bone marrow chimeras further demonstrated that this adjuvant did not require Th1 cells for IgG2a/c switching, but rather facilitated TLR7-dependent T-bet programming directly in B cells. This study underlines that adjuvant-directed IgG2a/c class-switching in vivo can occur in the absence of T cell help, via direct activation of TLR7 on B cells and positions DDA/TDB/3M-052 as a powerful adjuvant capable of eliciting type I-like immunity in B cells without strong induction of Th1 responses.
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.