Proceedings of The National Academy of Sciences, 1997
Calretinin (Cr) is a Ca2+ binding protein present in various populations of neurons distributed i... more Calretinin (Cr) is a Ca2+ binding protein present in various populations of neurons distributed in the central and peripheral nervous systems. We have generated Cr-deficient (Cr-/-) mice by gene targeting and have investigated the associated phenotype. Cr-/- mice were viable, and a large number of morphological, biochemical, and behavioral parameters were found unaffected. In the normal mouse hippocampus, Cr is
CCR5 is a CC chemokine receptor expressed on mem- ory lymphocytes, macrophages, and dendritic cel... more CCR5 is a CC chemokine receptor expressed on mem- ory lymphocytes, macrophages, and dendritic cells and also constitutes the main coreceptor for macrophage- tropic (or R5) strains of human immunodeficiency vi- ruses. In the present study, we investigated whether CCR5 was palmitoylated in its carboxyl-terminal do- main by generating alanine substitution mutants for the three cysteine residues present in this
CCR5 is a functional receptor for MIP-1a, MIP-1b, RANTES (regulated on activation normal T cell e... more CCR5 is a functional receptor for MIP-1a, MIP-1b, RANTES (regulated on activation normal T cell ex- pressed), MCP-2, and MCP-4 and constitutes the main coreceptor for macrophage tropic human and simian immunodeficiency viruses. By using CCR5-CCR2b chi- meras, we have shown previously that the second extra- cellular loop of CCR5 is the major determinant for che- mokine binding specificity, whereas
The pituitary hormone thyrotropin, or thyroid-stimulating hormone (TSH), is the main physiologica... more The pituitary hormone thyrotropin, or thyroid-stimulating hormone (TSH), is the main physiological agent that regulates the thyroid gland. The thyrotropin receptor (TSHR) was cloned by selective amplification with the polymerase chain reaction of DNA segments presenting sequence similarity with genes for G protein-coupled receptors. Out of 11 new putative receptor clones obtained from genomic DNA, one had sequence characteristics different from all the others. Although this clone did not hybridize to thyroid transcripts, screening of a dog thyroid complementary DNA (cDNA) library at moderate stringency identified a cDNA encoding a 4.9-kilobase thyroid-specific transcript. The polypeptide encoded by this thyroid-specific transcript consisted of a 398-amino acid residue amino-terminal segment, constituting a putative extracellular domain, connected to a 346-residue carboxyl-terminal domain that contained seven putative transmembrane segments. Expression of the cDNA conferred TSH responsiveness to Xenopus oocytes and Y1 cells and a TSH binding phenotype to COS cells. The TSHR and the receptor for luteinizing hormone-choriogonadotropin constitute a subfamily of G protein-coupled receptors with distinct sequence characteristics.
Human RANTES (CCL5) and MIP-1a (CCL3) bind and activate several CC chemokine receptors. RANTES is... more Human RANTES (CCL5) and MIP-1a (CCL3) bind and activate several CC chemokine receptors. RANTES is a high-affinity ligand for CCR1 and CCR5, and it binds CCR3 with moderate affinity and CCR4 with low affinity. MIP-1a has similar binding characteristics to RANTES except that it does not bind to CCR3. Here we have gen- erated a chimera of human MIP-1a and RANTES, called MIP/RANTES, consisting of the eight amino terminal residues of MIP-1a preceding the CC mo- tif, and the remainder of the sequence is RANTES. The chimera is able to induce chemotaxis of human monocytes. MIP/RANTES has >100-fold reduc- tion in binding to CCR1 and does not bind to CCR3 but retains full, functional binding to CCR5. It has equivalent affinity for CCR5 to MIP-1a and RAN- TES, binding with an IC50 of 1.12 nM, and is able to mobilize calcium and induce endocytosis of CCR5 in PBMC in a manner equi-potent to RAN- TES. It also retains the ability to inhibit R5 using HIV-1 strains. Therefore, we conclude that th...
Experimental T-cell-mediated hepatitis induced by concanavalin A (Con A) involves the production ... more Experimental T-cell-mediated hepatitis induced by concanavalin A (Con A) involves the production of different cytokines and chemokines and is characterized by leukocyte infiltration. Because the chemokine receptor CCR5 and its ligands (CCL3, CCL4, and CCL5) regulate leukocyte chemotaxis and activation, we investigated the role of CCR5 during Con A-induced liver injury. Serum levels of CCR5 ligands and their hepatic transcript levels were significantly increased after Con A injection, whereas CCR5+ liver mononuclear cells were recruited to the liver. CCR5-deficient (CCR5-/-) mice disclosed increased mortality and liver injury following Con A administration compared with wild-type mice. CCR5-/- mice also exhibited increased production of interleukin 4, tumor necrosis factor alpha, CCL3, CCL4, and CCL5, and a prominent liver mononuclear cell infiltrate, among which many cells were CCR1+. In vivo neutralization of CCR5 ligands in CCR5-/- mice afforded a protection against hepatitis only when CCL5 was neutralized. In conclusion, CCR5 deficiency exacerbates T-cell-mediated hepatitis, and leads to increased levels of CCR5 ligands and a more pronounced liver mononuclear infiltrate, suggesting that CCR5 expression can modulate severity of immuno-mediated liver injury.
Proceedings of The National Academy of Sciences, 1997
Calretinin (Cr) is a Ca2+ binding protein present in various populations of neurons distributed i... more Calretinin (Cr) is a Ca2+ binding protein present in various populations of neurons distributed in the central and peripheral nervous systems. We have generated Cr-deficient (Cr-/-) mice by gene targeting and have investigated the associated phenotype. Cr-/- mice were viable, and a large number of morphological, biochemical, and behavioral parameters were found unaffected. In the normal mouse hippocampus, Cr is
CCR5 is a CC chemokine receptor expressed on mem- ory lymphocytes, macrophages, and dendritic cel... more CCR5 is a CC chemokine receptor expressed on mem- ory lymphocytes, macrophages, and dendritic cells and also constitutes the main coreceptor for macrophage- tropic (or R5) strains of human immunodeficiency vi- ruses. In the present study, we investigated whether CCR5 was palmitoylated in its carboxyl-terminal do- main by generating alanine substitution mutants for the three cysteine residues present in this
CCR5 is a functional receptor for MIP-1a, MIP-1b, RANTES (regulated on activation normal T cell e... more CCR5 is a functional receptor for MIP-1a, MIP-1b, RANTES (regulated on activation normal T cell ex- pressed), MCP-2, and MCP-4 and constitutes the main coreceptor for macrophage tropic human and simian immunodeficiency viruses. By using CCR5-CCR2b chi- meras, we have shown previously that the second extra- cellular loop of CCR5 is the major determinant for che- mokine binding specificity, whereas
The pituitary hormone thyrotropin, or thyroid-stimulating hormone (TSH), is the main physiologica... more The pituitary hormone thyrotropin, or thyroid-stimulating hormone (TSH), is the main physiological agent that regulates the thyroid gland. The thyrotropin receptor (TSHR) was cloned by selective amplification with the polymerase chain reaction of DNA segments presenting sequence similarity with genes for G protein-coupled receptors. Out of 11 new putative receptor clones obtained from genomic DNA, one had sequence characteristics different from all the others. Although this clone did not hybridize to thyroid transcripts, screening of a dog thyroid complementary DNA (cDNA) library at moderate stringency identified a cDNA encoding a 4.9-kilobase thyroid-specific transcript. The polypeptide encoded by this thyroid-specific transcript consisted of a 398-amino acid residue amino-terminal segment, constituting a putative extracellular domain, connected to a 346-residue carboxyl-terminal domain that contained seven putative transmembrane segments. Expression of the cDNA conferred TSH responsiveness to Xenopus oocytes and Y1 cells and a TSH binding phenotype to COS cells. The TSHR and the receptor for luteinizing hormone-choriogonadotropin constitute a subfamily of G protein-coupled receptors with distinct sequence characteristics.
Human RANTES (CCL5) and MIP-1a (CCL3) bind and activate several CC chemokine receptors. RANTES is... more Human RANTES (CCL5) and MIP-1a (CCL3) bind and activate several CC chemokine receptors. RANTES is a high-affinity ligand for CCR1 and CCR5, and it binds CCR3 with moderate affinity and CCR4 with low affinity. MIP-1a has similar binding characteristics to RANTES except that it does not bind to CCR3. Here we have gen- erated a chimera of human MIP-1a and RANTES, called MIP/RANTES, consisting of the eight amino terminal residues of MIP-1a preceding the CC mo- tif, and the remainder of the sequence is RANTES. The chimera is able to induce chemotaxis of human monocytes. MIP/RANTES has >100-fold reduc- tion in binding to CCR1 and does not bind to CCR3 but retains full, functional binding to CCR5. It has equivalent affinity for CCR5 to MIP-1a and RAN- TES, binding with an IC50 of 1.12 nM, and is able to mobilize calcium and induce endocytosis of CCR5 in PBMC in a manner equi-potent to RAN- TES. It also retains the ability to inhibit R5 using HIV-1 strains. Therefore, we conclude that th...
Experimental T-cell-mediated hepatitis induced by concanavalin A (Con A) involves the production ... more Experimental T-cell-mediated hepatitis induced by concanavalin A (Con A) involves the production of different cytokines and chemokines and is characterized by leukocyte infiltration. Because the chemokine receptor CCR5 and its ligands (CCL3, CCL4, and CCL5) regulate leukocyte chemotaxis and activation, we investigated the role of CCR5 during Con A-induced liver injury. Serum levels of CCR5 ligands and their hepatic transcript levels were significantly increased after Con A injection, whereas CCR5+ liver mononuclear cells were recruited to the liver. CCR5-deficient (CCR5-/-) mice disclosed increased mortality and liver injury following Con A administration compared with wild-type mice. CCR5-/- mice also exhibited increased production of interleukin 4, tumor necrosis factor alpha, CCL3, CCL4, and CCL5, and a prominent liver mononuclear cell infiltrate, among which many cells were CCR1+. In vivo neutralization of CCR5 ligands in CCR5-/- mice afforded a protection against hepatitis only when CCL5 was neutralized. In conclusion, CCR5 deficiency exacerbates T-cell-mediated hepatitis, and leads to increased levels of CCR5 ligands and a more pronounced liver mononuclear infiltrate, suggesting that CCR5 expression can modulate severity of immuno-mediated liver injury.
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