Signaling molecules involved in immune responses in mussels

Immune system of molluscs is constituted by hemocytes and humoral factors that cooperate for the protection of the organism, triggering a wide range of immune responses. In molluscs, immune responses include phagocytosis, encapsulation, respiratory burst leading to reactive oxygen species (ROS) production and nitric oxide (NO) synthesis, release of antimicrobial molecules and the activation of phenoloxidase system. These responses are mediated firstly by a variety of hemocyte receptors binding to ligands that results to a cascade of signaling events. The processes of hemocytes adhesion to and migration through extracellular matrix (ECM) proteins play a crucial role in cell immunity. Results suggest that cadmium and oxidants induce adhesion to and migration through ECM proteins in Mytilus gallorovincialis hemocytes with the involvement of Na+/H+ exchanger (NHE), phosphatidylinositol-3 kinase (PI-3K), protein kinase C (PKC), NADPH oxidase, ROS and NO as well as with α2 integrin subunit. Furthermore, the data so far suggests the involvement of additional signaling molecules such as mitogen-activated protein kinases (MAPKs), signal transducers and activators of transcription (STATs), c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), cyclic adenosine monophosphate (cAMP), responsive element binding protein (CREB) and nuclear factor kappa B (NF-kB) in molluscs immunity. Further research in mollusc immune system may lead to a more sufficient protection and to a better control of these economically important organisms

Method development and validation for the quantitation of the complement inhibitor Cp40 in human and cynomolgus monkey plasma by UPLC-ESI-MS

Cp40 is a 14-amino acid cyclic analog of the peptidic complement inhibitor compstatin that binds with sub-nanomolar affinity to complement component C3 and has already shown promise in various models of complement-related diseases. The preclinical and clinical development of this compound requires a robust, accurate, and sensitive method for quantitatively monitoring Cp40 in biological samples. In this study, we describe the development and validation of an ultra-high performance liquid chromatography electrospray mass spectrometry method for the quantitation of Cp40 in human and non-human primate (NHP) plasma. Isotope-labeled Cp40 was used as an internal standard, allowing for the accurate and absolute quantitation of Cp40. Labeled and non-labeled Cp40 were extracted from plasma using reversed phase-solid phase extraction, with recovery rates exceeding 80%, indicating minor matrix effects. The triply charged states of Cp40 and isotope-labeled Cp40 were detected at m/z 596.60 and 600.34, respectively, via a Q-TOF mass spectrometer and were used for quantitation. The method was linear in the range of 0.18-3.58μg/mL (r(2)≥0.99), with precision values below 0.71% in NHP and 0.77% in human plasma. The accuracy of the method ranged from -2.17% to 17.99% in NHP and from -0.26% to 15.75% in human plasma. The method was successfully applied to the quantitation of Cp40 in cynomolgus monkey plasma after an initial intravenous bolus of 2mg/kg followed by repetitive subcutaneous administration at 1mg/kg. The high reproducibility, accuracy, and robustness of the method developed here render it suitable for drug monitoring of Cp40, and potentially other compstatin analogs, in both human and NHP plasma samples during pharmacokinetic and pharmacodynamic studies

Safety profile after prolonged C3 inhibition

The central component of the complement cascade, C3, is involved in various biological functions, including opsonization of foreign bodies, clearance of waste material, activation of immune cells, and triggering of pathways controlling development. Given its broad role in immune responses, particularly in phagocytosis and the clearance of microbes, a deficiency in complement C3 in humans is often associated with multiple bacterial infections. Interestingly, an increased susceptibility to infections appears to occur mainly in the first two years of life and then wanes throughout adulthood. In view of the well-established connection between C3 deficiency and infections, therapeutic inhibition of complement at the level of C3 is often considered with caution or disregarded. We therefore set out to investigate the immune and biochemical profile of non-human primates under prolonged treatment with the C3 inhibitor compstatin (Cp40 analog). Cynomolgus monkeys were dosed subcutaneously with Cp40, resulting in systemic inhibition of C3, for 1 week, 2 weeks, or 3 months. Plasma concentrations of both C3 and Cp40 were measured periodically and complete saturation of plasma C3 was confirmed. No differences in hematological, biochemical, or immunological parameters were identified in the blood or tissues of animals treated with Cp40 when compared to those injected with vehicle alone. Further, skin wounds showed no signs of infection in those treated with Cp40. In fact, Cp40 treatment was associated with a trend toward accelerated wound healing when compared with the control group. In addition, a biodistribution study in a rhesus monkey indicated that the distribution of Cp40 in the body is associated with the presence of C3, concentrating in organs that accumulate blood and produce C3. Overall, our data suggest that systemic C3 inhibition in healthy adult non-human primates is not associated with a weakened immune system or susceptibility to infections. © 2018 Elsevier Inc

Safety profile after prolonged C3 inhibition.

The central component of the complement cascade, C3, is involved in various biological functions, including opsonization of foreign bodies, clearance of waste material, activation of immune cells, and triggering of pathways controlling development. Given its broad role in immune responses, particularly in phagocytosis and the clearance of microbes, a deficiency in complement C3 in humans is often associated with multiple bacterial infections. Interestingly, an increased susceptibility to infections appears to occur mainly in the first two years of life and then wanes throughout adulthood. In view of the well-established connection between C3 deficiency and infections, therapeutic inhibition of complement at the level of C3 is often considered with caution or disregarded. We therefore set out to investigate the immune and biochemical profile of non-human primates under prolonged treatment with the C3 inhibitor compstatin (Cp40 analog). Cynomolgus monkeys were dosed subcutaneously with Cp40, resulting in systemic inhibition of C3, for 1 week, 2 weeks, or 3 months. Plasma concentrations of both C3 and Cp40 were measured periodically and complete saturation of plasma C3 was confirmed. No differences in hematological, biochemical, or immunological parameters were identified in the blood or tissues of animals treated with Cp40 when compared to those injected with vehicle alone. Further, skin wounds showed no signs of infection in those treated with Cp40. In fact, Cp40 treatment was associated with a trend toward accelerated wound healing when compared with the control group. In addition, a biodistribution study in a rhesus monkey indicated that the distribution of Cp40 in the body is associated with the presence of C3, concentrating in organs that accumulate blood and produce C3. Overall, our data suggest that systemic C3 inhibition in healthy adult non-human primates is not associated with a weakened immune system or susceptibility to infections