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(1) Development and characterization of mouse monoclonal antibodies to eight human complement components: Analysis of reactivity with orthologs of nine mammalian genera.[TOP]

Pubmed ID :30711050
Publication Date : //
To study complement function in mammalian leishmanioses, we developed mouse monoclonal antibodies to the human complement system components C1q, C4, factor D, factor H, factor B, properdin, C5 and C9. Antibody specificity was determined by indirect and capture ELISA and by Western blot. In flow cytometry analysis, seven antibodies recognized the cognate component on human serum-opsonized Leishmania promastigotes. Antibody reactivity was screened against promastigotes opsonized with sera of nine mammalian genera: pig, guinea pig, goat, rabbit, cat, dog, hamster, jird and rat. No antibody recognized jird epitopes on promastigotes. Anti-C4, -properdin, and -C5b reacted with the orthologous protein of all other mammals tested except cat (anti-properdin) and hamster (anti-C5b); anti-C9 only recognized the rabbit ortholog, and anti-C1q, -factor B and -factor H did not react with any of the nine orthologs. Such interspecies crossreactive antibodies can be valuable tools for analysis of mammalian complement function in infectious diseases.

Authors : Monedero Marta, Infantes-Lorenzo José A, Moreno Inmaculada, Martín Ana Belén, Macias Rocio I R, Toraño Alfredo, Domínguez Mercedes,

(2) Crucial Role for Basophils in Acquired Protective Immunity to Tick Infestation.[TOP]

Pubmed ID :30581391
Publication Date : //
Ticks are blood-sucking arthropods that can transmit various pathogenic organisms to host animals and humans, causing serious infectious diseases including Lyme disease. Tick feeding induces innate and acquired immune responses in host animals, depending on the combination of different species of animals and ticks. Acquired tick resistance (ATR) can diminish the chance of pathogen transmission from infected ticks to the host. Hence, the elucidation of cellular and molecular mechanism underlying ATR is important for the development of efficient anti-tick vaccines. In this review article, we briefly overview the history of studies on ATR and summarize recent findings, particularly focusing on the role for basophils in the manifestation of ATR. In several animal species, including cattle, guinea pigs, rabbits and mice, basophil accumulation is observed at the tick re-infestation site, even though the frequency of basophils among cellular infiltrates varies in different animal species, ranging from approximately 3% in mice to 70% in guinea pigs. Skin-resident, memory CD4 T cells contribute to the recruitment of basophils to the tick re-infestation site through production of IL-3 in mice. Depletion of basophils before the tick re-infestation abolishes ATR in guinea pigs infested with and mice infested with , demonstrating the crucial role of basophils in the manifestation of ATR. The activation of basophils via IgE and its receptor FcεRI is essential for ATR in mice. Histamine released from activated basophils functions as an important effector molecule in murine ATR, probably through promotion of epidermal hyperplasia which interferes with tick attachment or blood feeding in the skin. Accumulating evidence suggests the following scenario. The 1 tick infestation triggers the production of IgE against tick saliva antigens in the host, and blood-circulating basophils bind such IgE on the cell surface via FcεRI. In the 2 infestation, IgE-armed basophils are recruited to tick-feeding sites and stimulated by tick saliva antigens to release histamine that promotes epidermal hyperplasia, contributing to ATR. Further studies are needed to clarify whether this scenario in mice can be applied to ATR in other animal species and humans.

Authors : Karasuyama Hajime, Tabakawa Yuya, Ohta Takuya, Wada Takeshi, Yoshikawa Soichiro,

(3) Preclinical pharmacokinetic evaluation to facilitate repurposing of tyrosine kinase inhibitors nilotinib and imatinib as antiviral agents.[TOP]

Pubmed ID :30514402
Publication Date : //
Several tyrosine kinase inhibitors (TKIs) developed as anti-cancer drugs, also have anti-viral activity due to their ability to disrupt productive replication and dissemination in infected cells. Consequently, such drugs are attractive candidates for "repurposing" as anti-viral agents. However, clinical evaluation of therapeutics against infectious agents associated with high mortality, but low or infrequent incidence, is often unfeasible. The United States Food and Drug Administration formulated the "Animal Rule" to facilitate use of validated animal models for conducting anti-viral efficacy studies.

Authors : Ananthula Hari Krishna, Parker Scott, Touchette Erin, Buller R Mark, Patel Gopi, Kalman Daniel, Salzer Johanna S, Gallardo-Romero Nadia, Olson Victoria, Damon Inger K, Moir-Savitz Tessa, Sallans Larry, Werner Milton H, Sherwin Catherine M, Desai Pankaj B,

(4) Evaluation of the anti-asthmatic and antitussive potentials of methanol leaf extract of Napoleona vogelii in rodents.[TOP]

Pubmed ID :30396068
Publication Date : //
Napoleona vogelii is used in ethnomedicine for the treatment of asthma and cough. This study evaluated antiasthmatic and antitussive properties of its methanol leaf extract (NVE) in rodents. Phytochemical screening was conducted using established methods. Acute oral toxicity test was done in mice and guinea pigs. Ovalbumin (OA)-sensitized guinea pigs were orally pretreated with 100, 200 or 400 mg/kg/day of NVE or 0.5 mg/kg/day of salbutamol for 14 days before exposure to 0.2% histamine aerosol. Latency to preconvulsive dyspnea (PCD), tracheal fluid volume (TFV), flow rate (FR), and tracheal morphometry (TM) were evaluated. Tracheal rings from sensitized guinea pigs were tested in organ baths for antispasmodic and spasmolytic effects. Citric acid and ammonium hydroxide cough models were used to evaluate antitussive effects in guinea pigs and mice respectively. Tannins, alkaloids, flavonoids, and phenolic substances were found in NVE. LD values in mice and guinea pigs were greater than 5000 mg/kg. NVE caused a significant (P < 0.05) increase in the latency to PCD and a decrease in TFV in the group treated with 200 mg/kg. TM indicated a reduction in airway narrowing in NVE-treated groups. The presence of NVE significantly attenuated responses of tracheal rings to carbachol. Its addition to carbachol precontracted rings resulted in significant relaxation. E for calcium concentration-response was significantly (P < 0.01) decreased in the presence of NVE. Cough bouts dose-dependently decreased significantly (P < 0.05) in guinea pigs and mice. We conclude that NVE seems safe and possesses anti-asthmatic effect that involves inhibition of calcium influx. It also has antitussive properties that may be peripherally mediated.

Authors : Adejayan Adesola A, Ozolua Raymond I, Uwaya Dickson O, Eze Gerald I, Ezike Adaobi C,

(5) Functional mechanism of tracheal relaxation, antiasthmatic, and toxicological studies of 6-hydroxyflavone.[TOP]

Pubmed ID :30394554
Publication Date : //
Preclinical Research & Development Previously, we described tracheal rat rings relaxation by several flavonoids, being 6-hydroxyflavone (6-HOF) the most active derivative of the series. Thus, its mechanism of action was determined in an ex vivo tracheal rat ring bioassay. The anti-asthmatic effect was assayed in in vivo OVAlbumin (OVA)-sensitized guinea pigs. Finally, the toxicological profile of 6-HOF was studied based on Organization of Economic Cooperation and Development guidelines with modifications. 6-HOF-induced relaxation appears to be related with receptor-operated calcium channel and voltage-operated calcium channel blockade as the main mechanism of action, and also through the production of relaxant second messengers NO and cGMP. Molecular docking supports that 6-HOF acts as calcium channel blocker and by activation of nitric oxide synthase. In addition, the in vivo anti-asthmatic experiments demonstrate the dose-dependent significant anti-allergic effect of 6-HOF induced by OVA, with best activity at 50 /kg. Finally, toxicological studies determined a LD50 > 2,000 mg/kg and, after 28 day of treatment with 6-HOF (50 mg/kg) by intragastric route, mice did not exhibit evidence of any significant toxicity. In conclusion, experiments showed that 6-HOF exerts significant relaxant activity through calcium channel blockade, and possibly, by NO/cGMP-system stimulation on rat trachea, which interferes with the contraction mechanism of smooth muscle cells in the airways. In addition, the flavonoid shows potential anti-asthmatic properties in an anti-allergic pathway. Furthermore, because the pharmacological and safety evidence, we propose this flavonoid as lead for the development of a novel therapeutic agent for the treatment of asthma and related respiratory diseases.

Authors : Flores-Flores Angélica, Estrada-Soto Samuel, Millán-Pacheco César, Bazán-Perkins Blanca, Villalobos-Molina Rafael, Moreno-Fierros Leticia, Hernández-Pando Rogelio, García-Jiménez Sara, Rivera-Leyva Julio César,

(6) Drug-receptor kinetics and sigma-1 receptor affinity differentiate clinically evaluated histamine H receptor antagonists.[TOP]

Pubmed ID :30359639
Publication Date : //
The histamine H receptor is a G protein-coupled receptor (GPCR) drug target that is highly expressed in the CNS, where it acts as both an auto- and hetero-receptor to regulate neurotransmission. As such, it has been considered as a relevant target in disorders as varied as Alzheimer's disease, schizophrenia, neuropathic pain and attention deficit hyperactivity disorder. A range of competitive antagonists/inverse agonists have progressed into clinical development, with pitolisant approved for the treatment of narcolepsy. Given the breadth of compounds developed and potential therapeutic indications, we assessed the comparative pharmacology of six investigational histamine H agents, including pitolisant, using native tissue and recombinant cells. Whilst all of the compounds tested displayed robust histamine H receptor inverse agonism and did not differentiate between the main H receptor splice variants, they displayed a wide range of affinities and kinetic properties, and included rapidly dissociating (pitolisant, S 38093-2, ABT-239) and slowly dissociating (GSK189254, JNJ-5207852, PF-3654746) agents. S 38093-2 had the lowest histamine H receptor affinity (pK values 5.7-6.2), seemingly at odds with previously reported, potent in vivo activity in models of cognition. We show here that at pro-cognitive and anti-hyperalgesic/anti-allodynic doses, S 38093-2 preferentially occupies the mouse sigma-1 receptor in vivo, only engaging the histamine H receptor at doses associated with wakefulness promotion and neurotransmitter (histamine, ACh) release. Furthermore, pitolisant, ABT-239 and PF-3654746 also displayed appreciable sigma-1 receptor affinity, suggesting that this property differentiates clinically evaluated histamine H receptor antagonists and may play a role in their efficacy.

Authors : Riddy Darren M, Cook Anna E, Shackleford David M, Pierce Tracie L, Mocaer Elisabeth, Mannoury la Cour Clotilde, Sors Aurore, Charman William N, Summers Roger J, Sexton Patrick M, Christopoulos Arthur, Langmead Christopher J,

(7) Virus-like particles of recombinant PCV2b carrying FMDV-VP1 epitopes induce both anti-PCV and anti-FMDV antibody responses.[TOP]

Pubmed ID :30338355
Publication Date : //
Mixed infection of porcine circovirus type 2 (PCV2) and foot-and-mouth disease virus (FMDV) is devastating to swine populations. To develop an effective vaccine that can protect the pigs from the infection of PCV2 and FMDV, we used the neutralizing B cell epitope region (aa 135-160) of FMDV to replace the regions aa 123-151 and aa 169-194 of the PCV2b Cap protein to generate a recombinant protein designated as Capfb. The Capfb protein was expressed in Escherichia coli system and the purified Capfb protein assembled into virus-like particles (VLPs) through dialysis. The ability of the Capfb protein to induce effective immune response against FMDV and PCV2b was tested in mice and guinea pigs. The results showed that the Capfb-VLPs could elicit anti-PCV2b and anti-FMDV antibody response in mice and guinea pigs without inducing antibodies against decoy epitope. Moreover, the Capfb-VLPs could enhance the percentage and activation of B cells in lymph nodes when the mice were stimulated with inactivated FMDV or PCV2b. These data suggested that the Capfb-VLPs could be an efficacious candidate antigen for developing a novel PCV2b-FMDV bivalent vaccine.

Authors : Li Xin, Meng Xiuping, Wang Shengnan, Li Zhiqin, Yang Lei, Tu Liqun, Diao Wenzhen, Yu Cheng, Yu Yongli, Yan Chaoying, Wang Liying,

(8) Cyclopeptide COR-1 to treat beta1-adrenergic receptor antibody-induced heart failure.[TOP]

Pubmed ID :30125285
Publication Date : //
Despite advances in pharmacotherapy, heart failure still incurs significant morbidity and mortality. Stimulating antibodies directed against the secondextracellular loop of the human ß1-adrenergic receptor (anti-ß1EC2) cause myocyte damage and heart failure in rats. This receptor domain is 100% homologous between rats and humans.

Authors : Boivin-Jahns Valérie, Uhland Kerstin, Holthoff Hans-Peter, Beyersdorf Niklas, Kocoski Vladimir, Kerkau Thomas, Münch Götz, Lohse Martin J, Ungerer Martin, Jahns Roland,

(9) The adhesion function of the sodium channel beta subunit (β1) contributes to cardiac action potential propagation.[TOP]

Pubmed ID :30106376
Publication Date : //
Computational modeling indicates that cardiac conduction may involve ephaptic coupling - intercellular communication involving electrochemical signaling across narrow extracellular clefts between cardiomyocytes. We hypothesized that β1(SCN1B) -mediated adhesion scaffolds -activating Na1.5 (SCN5A) channels within narrow (<30 nm) perinexal clefts adjacent to gap junctions (GJs), facilitating ephaptic coupling. Super-resolution imaging indicated preferential β1 localization at the perinexus, where it co-locates with Na1.5. Smart patch clamp (SPC) indicated greater sodium current density (I) at perinexi, relative to non-junctional sites. A novel, rationally designed peptide, βadp1, potently and selectively inhibited β1-mediated adhesion, in electric cell-substrate impedance sensing studies. βadp1 significantly widened perinexi in guinea pig ventricles, and selectively reduced perinexal I, but not whole cell I, in myocyte monolayers. In optical mapping studies, βadp1 precipitated arrhythmogenic conduction slowing. In summary, β1-mediated adhesion at the perinexus facilitates action potential propagation between cardiomyocytes, and may represent a novel target for anti-arrhythmic therapies.

Authors : Veeraraghavan Rengasayee, Hoeker Gregory S, Alvarez-Laviada Anita, Hoagland Daniel, Wan Xiaoping, King D Ryan, Sanchez-Alonso Jose, Chen Chunling, Jourdan Jane, Isom Lori L, Deschenes Isabelle, Smyth James W, Gorelik Julia, Poelzing Steven, Gourdie Robert G,

(10) Connexin 30.2 is expressed in exocrine vascular endothelial and ductal epithelial cells throughout pancreatic postnatal development.[TOP]

Pubmed ID :30100173
Publication Date : //
Previously we have demonstrated that the GJ protein connexin 30.2 (Cx30.2) is expressed in pancreatic beta cells and endothelial cells (ECs) of the islet. In the present study, we address whether Cx30.2 is expressed in the exocrine pancreas, including its vascular system. For this, adult mouse pancreatic sections were double labeled with specific antibodies against Cx30.2 and CD31, an endothelial cell marker, or with anti-α-actin smooth muscle, a smooth muscle cell (SMC) marker or anti-mucin-1, a marker of epithelial ductal cells, using immunofluorescence (IF) studies. Cx30.2-IF hot spots were found at junctional membranes of exocrine ECs and SMCs of blood vessels. Furthermore, Cx30.2 was localized in mucin-1 positive cells or epithelial ductal cells. Using immunohistochemistry (IHC) studies, it was found that in vessels and ducts of different diameters, Cx30.2 was also expressed in these cell types. In addition, it was found that Cx30.2 is already expressed in these cell types in pancreatic sections of 3, 14 and 21 days postpartum. Moreover, this cell specific pattern of expression was also found in the adult rat, hamster and guinea pig pancreas. Expression of Cx30.2 mRNA and protein in the pancreas of all these species was confirmed by RT-PCR and Western blot studies. Overall, our results suggest that intercellular coupling mediated by Cx30.2 intercellular channels may synchronize the functional activity of ECs and SMCs of vascular cells, as well as of epithelial ductal cells after birth.

Authors : Coronel-Cruz C, Sánchez I, Hernández-Tellez B, Rodríguez-Mata V, Pinzón-Estrada E, Castell-Rodríguez A, Pérez-Armendariz E M,