Project description:The acidic tumor microenvironment in melanoma drives immune evasion by up-regulating cyclic adenosine monophosphate (cAMP) in tumor-infiltrating monocytes..Melanoma growth can be suppressed by releasing non-toxic concentrations of an adenylate cyclase (AC) inhibitor from polypept(o)id micelles at the tumor site in an immune cell-dependent manner.
Project description:The acidic tumor microenvironment in melanoma drives immune evasion by up-regulating cyclic adenosine monophosphate (cAMP) in tumor-infiltrating monocytes. Here we show that the release of non-toxic concentrations of an adenylate cyclase (AC) inhibitor from poly(sarcosine)-block-poly(L-glutamic acid γ-benzyl ester) (polypept(o)id) copolymer micelles restores antitumor immunity. In combination with selective, non-therapeutic regulatory T cell depletion, AC inhibitor micelles achieve a complete remission of established B16-F10-OVA tumors. Single-cell sequencing of melanoma-infiltrating immune cells shows that AC inhibitor micelles reduce the number of anti-inflammatory myeloid cells and checkpoint receptor expression on T cells. AC inhibitor micelles thus represent an immunotherapeutic measure to counteract melanoma immune escape.
Project description:Cyclic nucleotide signaling is pivotal to the asexual growth of T. gondii; however, little do we know about its counter-regulation in this parasite. We identified 18 phosphodiesterase (PDE1-18) enzymes, most of which form apicomplexan-specific clades and lack typical regulatory motifs found in mammalian PDEs. Genomic epitope-tagging in the tachyzoite stage showed the variable expression of 11 phosphodiesterases with diverse subcellular distribution. Most PDEs can degrade cAMP as well as cGMP with different affinity except for PDE2 which is cAMP-specific. In our extended work, we examined PDE1,2,7-9 for their physiological importance during the lytic cycle. Surprisingly, tachyzoites can tolerate the deletion of PDE1, 7-9 genes with no apparent impairment of the lytic cycle, suggesting remarkable plasticity in the cyclic nucleotide signaling. Co-ablation of PDE1 and PDE2 is detrimental to the parasite growth due to impairment of motility, invasion, egress and replication. The immunogold transmission electron microscopy revealed TgPDE1,2 in the cytomembranes including the inner membrane complex. Not least, we identified a number of proteins that interact with PDE1 and PDE2 and thereby regulate cAMP/cGMP signaling in tachyzoites. In summary, our work lays a strong foundation to decipher the mechanism of cyclic nucleotide signaling and exploit it for therapeutic inhibition of T. gondii.
Project description:The impact of 2',3'-cyclic nucleotide monophosphates (2',3'-cNMPs) on global gene expression in E. coli was investigated by heterologous expression of a 2',3'-cyclic nucleotide phosphodiesterase (CNPase), which reduces intracellular 2',3'-cNMP levels.
Project description:The impact of 2',3'-cyclic nucleotide monophosphates (2',3'-cNMPs) on global gene expression in S. Typhimurium was investigated by heterologous expression of a 2',3'-cyclic nucleotide phosphodiesterase (CNPase), which reduces intracellular 2',3'-cNMP levels.
Project description:The aim of the project was to characterize structural changes that occur on the rod cyclic nucleotide-gated channel upon interaction with calmodulin (CaM) directly in the native membrane.
Project description:The impact of 2',3'-cyclic nucleotide phosphodiesterase (CNPase) on global gene expression in Salmonella was investigated by heterologous expression of mammalian CNPase in a strain containing a deletion of the 'rna' gene. 'rna' encodes an endoribonuclease capable of hydrolyzing RNA into 2',3'-cyclic nucleotide monophosphates (2',3'-cNMPs) such that deletion of 'rna' drastically reduces 2',3'-cNMPs presence to undetectable levels. Expression of CNPase in this strain allowed any effects of CNPase unrelated to 2',3'-cNMPs to be observed.
Project description:The cone photoreceptor cyclic nucleotide-gated (CNG) channel is essential for central and color vision and visual acuity. Mutations in the channel subunits CNGA3 and CNGB3 are associated with achromatopsia and cone dystrophy. We investigated the gene expression profiles in mouse retina with CNG channel deficiency on a cone-dominant background, i.e., CNGA3-/-/Nrl-/- and CNGB3-/-/Nrl-/- mice, relative to Nrl-/- mice.
Project description:The cone photoreceptor cyclic nucleotide-gated (CNG) channel is essential for central and color vision and visual acuity. Mutations in the channel subunits CNGA3 and CNGB3 are associated with achromatopsia and cone dystrophy. We investigated the gene expression profiles in mouse retina with CNG channel deficiency on a cone-dominant background, i.e., CNGA3-/-/Nrl-/- and CNGB3-/-/Nrl-/- mice, relative to Nrl-/- mice. Total RNA was isolated from 2 retinas per animal (CNGA3-/-/Nrl-/-, CNGB3-/-/Nrl-/-, and Nrl-/- mice). The background strain for these mutations was C57bl/6.
Project description:The impact of 2',3'-cyclic nucleotide phosphodiesterase (CNPase) on global gene expression in E. coli was investigated by heterologous expression of mammalian CNPase in a strain containing a deletion of the 'rna' gene. 'rna' encodes an endoribonuclease capable of hydrolyzing RNA into 2',3'-cyclic nucleotide monophosphates (2',3'-cNMPs) such that deletion of 'rna' drastically reduces 2',3'-cNMPs levels to undetectable levels. Expression of CNPase in this strain allowed any effects of CNPase unrelated to 2',3'-cNMPs to be observed.