Sublingual immunotherapy of allergic diseases.

The only disease-modifying treatment that is available for allergic patients is allergen-specific immunotherapy. Two competing application forms are used: subcutaneous immunotherapy, which has been used for > 90 years, and a relatively new immunotherapy where the allergen is applied sublingually. Numerous studies have shown efficacy for subcutaneous immunotherapy and have identified possible mechanisms that are responsible for the observed reduction in allergic responses.

Effects of a low-molecular-weight CCR-3 antagonist on chronic experimental asthma.

Eosinophils represent one of the main effector cell populations of allergic airway inflammation and allergic bronchial asthma. Their infiltration correlates with many characteristics of the disease, including airway hyperresponsiveness (AHR) and increased mucus production. CCR-3 is the principle chemokine receptor involved in eosinophil attraction into inflamed tissue.

The galanin receptor type 2 initiates multiple signaling pathways in small cell lung cancer cells by coupling to G(q), G(i) and G(12) proteins.

Neuropeptides like galanin produced and released by small cell lung cancer (SCLC) cells are considered principal mitogens in these tumors. We identified the galanin receptor type 2 (GALR2) as the only galanin receptor expressed in H69 and H510 cells. Photoaffinity labeling of G proteins in H69 cell membranes revealed that GALR2 activates G proteins of three subfamilies: G(q), G(i), and G(12).

Cell cycle-dependent coupling of the vasopressin V1a receptor to different G proteins.

Arginine vasopressin (AVP) regulates biological processes by binding to G protein-coupled receptors. In Swiss 3T3 fibroblasts, expressing the V(1a) subtype of vasopressin receptors, AVP mobilizes calcium from intracellular stores. In proliferating cells, the AVP-induced increase in intracellular calcium concentration ([Ca(2+)](i)) was mediated by G proteins of the G(q) family, which are insensitive to pertussis toxin (PTX) pretreatment of the cells.

Expression of TRPC3 in Chinese hamster ovary cells results in calcium-activated cation currents not related to store depletion.

TRPC3 (or Htrp3) is a human member of the trp family of Ca2+-permeable cation channels. Since expression of TRPC3 cDNA results in markedly enhanced Ca2+ influx in response to stimulation of membrane receptors linked to phospholipase C (Zhu, X., J.

A betagamma dimer derived from G13 transduces the angiotensin AT1 receptor signal to stimulation of Ca2+ channels in rat portal vein myocytes.

A G protein composed of alpha13, beta1, and gamma3 subunits selectively couples the angiotensin AT1A receptors to increase cytoplasmic Ca2+ concentration ([Ca2+]i) in rat portal vein myocytes (Macrez-Leprêtre, N., Kalkbrenner, F., Morel, J.

G protein heterotrimer Galpha13beta1gamma3 couples the angiotensin AT1A receptor to increases in cytoplasmic Ca2+ in rat portal vein myocytes.

The subunit composition of angiotensin AT1 receptor-activated G protein was identified by using antisense oligonucleotide injection into the nucleus of rat portal vein myocytes. In these cells, we have previously shown that increases in the cytoplasmic calcium concentration ([Ca2+]i) induced by activation of angiotensin AT1 receptors were dependent on extracellular Ca2+ entry by L-type Ca2+ channels and subsequent Ca2+-induced Ca2+ release from the intracellular stores. The angiotensin AT1 receptor-activated increases in [Ca2+]i were selectively inhibited by injection of antisense oligonucleotides directed against the mRNAs coding for the alpha13, beta1, and gamma3 subunits.

Distinct functions of Gq and G11 proteins in coupling alpha1-adrenoreceptors to Ca2+ release and Ca2+ entry in rat portal vein myocytes.

In this study, we identified the subunit composition of Gq and G11 proteins coupling alpha1-adrenoreceptors to increase in cytoplasmic Ca2+ concentration ([Ca2+]i) in rat portal vein myocytes maintained in short-term primary culture. We used intranuclear antisense oligonucleotide injection to inhibit selectively the expression of subunits of G protein. Increases in [Ca2+]i were measured in response to activation of alpha1-adrenoreceptors, angiotensin AT1 receptors, and caffeine.

Direct activation of trpl cation channels by G alpha11 subunits.

G proteins of the Gq/11 subfamily functionally couple cell surface receptors to phospholipase C beta (PLC beta) isoforms. Stimulation of PLC beta induces Ca2+ elevation by inositol 1,4,5-trisphosphate (InsP3)-mediated Ca2+ release and store-dependent 'capacitative' Ca2+ entry through Ca(2+)-permeable channels. The Drosophila trp gene, as well as some human trp homologs, code for such store-operated channels.

Transport of protein kinase C alpha into the nucleus requires intact cytoskeleton while the transport of a protein containing a canonical nuclear localization signal does not.

Protein kinase C undergoes a redistribution from the cytosol into the nucleus upon various stimuli. Since protein kinase C does not contain any known nuclear localization signal, the exact pathway and mechanism of the translocation into the nucleus is not known. We used immunofluorescence microscopy to investigate the role of the cytoskeleton in this process, and to detect the subcellular distribution of protein kinase C alpha in NIH 3T3 fibroblasts.

Cloning and functional expression of a human Ca2+-permeable cation channel activated by calcium store depletion.

Depletion of intracellular calcium stores generates a signal that activates Ca2+-permeable channels in the plasma membrane. We have identified a human cDNA, TRPC1A, from a human fetal brain cDNA library. TRPC1A is homologous to the cation channels trp and trpl in Drosophila and is a splice variant of the recently identified cDNA Htrp-1.

A heterotrimeric G protein complex couples the muscarinic m1 receptor to phospholipase C-beta.

We addressed the question as to which subtypes of G protein subunits mediate the activation of phospholipase C-beta by the muscarinic m1 receptor. We used the rat basophilic leukemia cell line RBL-2H3-hm1 stably transfected with the human muscarinic m1 receptor cDNA. We microinjected antisense oligonucleotides into the nuclei of the cells to inhibit selectively the expression of G protein subunits; 48 hr later muscarinic receptors were activated by carbachol, and the increase in free cytosolic calcium concentration ([Ca2+]i) was measured.

A specific G(o) heterotrimer couples somatostatin receptors to voltage-gated calcium channels in RINm5F cells.

The peptide hormone somatostatin inhibits glucose-induced insulin secretion in the rat insulinoma RINm5F cells by inhibition of voltage-gated calcium channels. Here we used micro-injection of antisense oligonucleotides directed against subtypes of G-protein subunits to determine the subunit composition involved in somatostatin-induced inhibition of voltage-gated calcium channels in RINmF5 cells. Injection of antisense oligonucleotides annealing to the respective mRNA of G alpha o2, G beta 1 and G gamma 3 reduced the somatostatin-induced inhibition of calcium channels in these cells.

Diversity and selectivity of receptor-G protein interaction.

Cells in a living organism communicate with each other through extracellular molecules such as hormones, neurotransmitters, and growth factors. The majority of these molecules transmit their signal by interacting with a three-protein transmembrane signal transduction system whose single components interact sequentially and reversibly. Agonist binding to a heptahelical receptor results in activation of heterotrimeric guanine nucleotide-binding proteins (G proteins) that modulate the activity of one or more effector systems.

Subunit composition of G(o) proteins functionally coupling galanin receptors to voltage-gated calcium channels.

The neuropeptide galanin is widely expressed in the central nervous system and other tissues and induces different cellular reactions, e.g. hormone release from pituitary and inhibition of insulin release from pancreatic B cells.

Nuclear proto-oncogene products transactivate the human papillomavirus type 16 promoter.

Human papillomavirus (HPV) type 16 and 18 viral genomes are frequently detected in cervical and penile cancer biopsies. Although this strongly suggests a prominent role for HPV infection in the development of genital cancer, other genetic or environmental factors are also involved. Genital cancer is postulated to result from loss of cellular control functions, which leads to an unregulated expression of HPV oncogenic proteins.

The Drosophila cation channel trpl expressed in insect Sf9 cells is stimulated by agonists of G-protein-coupled receptors.

Structures and regulations of vertebrate channels responsible for sustained calcium elevations after hormone stimulation are largely unknown. Therefore, the Drosophila photoreceptor channels, trp and trpl, which are assumed to be involved in calcium influx, serve as model system, trpl expressed in Sf9 cells showed spontaneous activity. Hormonal stimulations of calcium influx (detected by fura-2) and of an outwardly rectifying current were observed in Sf9 cells coinfected with baculoviruses encoding trpl and various heptahelical receptors for histamine, thrombin, and thromboxane A2, all known to cause phospholipase C-beta activation in mammalian cells.

The carboxyterminus of human c-myb protein stimulates activated transcription in trans.

The cellular c-myb gene encodes a transcription factor composed of a DNA-binding domain, a transactivating domain and a regulatory domain located at its carboxy (C-) terminus. The latter one is deleted in the transforming viral protein v-Myb. Here we show that deletion of the C-terminus of c-Myb increases the transcriptional transactivation activity of c-Myb defining it as cis-acting negative regulatory domain.

G12 and G13 alpha-subunits are immunochemically detectable in most membranes of various mammalian cells and tissues.

The cDNAs of two putatively pertussis toxin-insensitive G-protein alpha-subunits, alpha 12 and alpha 13, were recently cloned. mRNA analyses based on the reverse transcriptase polymerase chain reaction indicated a widespread distribution of both mRNAs [Strathmann, M. P.

Transactivation of the human c-myc gene by c-Myb.

We analyse the contribution of six Myb-binding sites in the upstream c-myc sequences to transactivation by co-transfection assays. Surprisingly, deletion of the six Myb-binding sites did not influence the transactivation of c-myc by c-Myb protein. Instead, the strongest transactivation was observed with a c-myc reporter plasmid which contains only 450 bp of exon 1 including the c-myc promoter P2.