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Comparative Immunology
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
If insects are injected with heat-killed bacteria, proteins appear in their hemolymph that can prevent bacterial growth or cause bacterial lysis. For example, following infection of tomato hornworms, their hemocytes and hemolymph plasma enzymes degrade bacterial cell walls releasing peptidogiyeans. These peptidoglycans in turn elicit increased synthesis of antibacterial proteins which accumulate in the hemolymph. In some insects toxins induce proteins that mimic antibody molecules. Among the proteins induced in this way is lysozyme. These antibacterial proteins appear about two hours after exposure to the bacteria and reach peak levels at twenty-four hours. In some insects, the activity is short-lived and disappears by four days; in others, it may last for several months. Passive immunity can be conferred on recipient insects by transfer of hemolymph from immune insects. Little is known about the mechanisms involved in the production of these antibacterial proteins.
Aedes Mosquitoes: The Universal Vector
Published in Jagriti Narang, Manika Khanuja, Small Bite, Big Threat, 2020
Annette Angel, Bennet Angel, Neelam Yadav, Jagriti Narang, Surender Singh Yadav, Vinod Joshi
The circulatory system of Aedes mosquitoes is similar to that of other insects, that is, open type comprising a heart enclosed in the pericardial sinus and vessels (Klowden, 2007). The heart is tubular in shape and has pores called ostia, which communicate with the pericardial sinus (Fig. 1.18). The blood is also called hemolymph and is composed of organic phosphates, uric acid, and trehalose. The hemolymph does not contain any pigment (Andereck et. al., 2010; Glenn et. al., 2010).
Immunology
Published in Paul Pumpens, Single-Stranded RNA Phages, 2020
The “immune” response in insects compared with vertebrates was studied by Ziprin and Hartman (1971). They followed to the fate of the phage MS2 after injection of the intact particles into larvae of the darkling beetle Tenebrio molitor. By the patterns of the phage clearance from hemolymph, the authors concluded that the insects did not produce agents capable of inactivating the phage particles.
CNS serotonin content mediating food deprivation-enhanced learning is regulated by hemolymph tryptophan concentration and autophagic flux in the pond snail
Published in Nutritional Neuroscience, 2023
Yuki Totani, Junko Nakai, Dai Hatakeyama, Varvara E. Dyakonova, Ken Lukowiak, Etsuro Ito
Tryptophan (KA1916, Abnova, Taipei, Taiwan) and 5-HT (KA2518, Abnova) concentrations were measured using enzyme-linked immunosorbent assay (ELISA) kits according to the manufacturer’s protocols. The hemolymph samples were collected as follows. After the water around the snail was wiped off with absorbent paper, the snail’s foot was poked with a needle to make it retract into the shell to expel hemolymph from the renal pore; the hemolymph sample was collected and centrifuged at 2500×g for 10 min at 4°C; and the supernatant was separated and stored at −20°C. The CNS samples were collected as follows. The dissected CNS was sonicated in the ice-cold Lymnaea saline (10 mM HEPES at pH 7.9, 50 mM NaCl, 1.6 mM KCl, 2.0 mM MgCl2 and 3.5 mM CaCl2). To avoid oxidative degradation of the 5-HT, the samples were sonicated in saline with the stabilizer provided in the ELISA kit. Because the amount of tryptophan in the CNS is very small, we combined CNS tryptophan samples from 5 snails into a single sample for measurement. After sonication, the samples were centrifuged at 18,000×g for 10 min at 4°C, and the supernatants were separated and stored at −20°C.
Mechanisms of nanotoxicity – biomolecule coronas protect pathological fungi against nanoparticle-based eradication
Published in Nanotoxicology, 2020
Roland H. Stauber, Dana Westmeier, Madita Wandrey, Sven Becker, Dominic Docter, Guo-Bin Ding, Eckhard Thines, Shirley K. Knauer, Svenja Siemer
Currently, research heavily relies on murine models for studying the activity of nano-based antimicrobials as well as determining nanotoxicology (Docter, Westmeier, et al. 2015; Westmeier, Hahlbrock, et al. 2018). However, there is a growing public consciousness demanding alternative experimental models, as there are ethical, financial, and logistical problems connected with the use of mammals. Galleria mellonella can be infected by numerous microorganisms including fungi or bacteria, and thus is suggested to investigate infections and their therapies (Tsai, Loh, and Proft 2016; Siemer, Westmeier, et al. 2018). Galleria mellonella larvae can be easily and inexpensively obtained in large numbers and have a short life cycle. While lacking a typical vertebrate adaptive immune response, insects possess well-developed innate responses with remarkable similarities to vertebrates. In particular, their antifungal immunity also involves cellular and humoral components. The hemolymph system contains different types of hemocytes, important for recognition and elimination of microorganisms. Moreover, insects and humans have evolutionary conserved antimicrobial peptides, including defensins (Jiang et al. 2018; Gomez-Lopez et al. 2014; Ramarao, Nielsen-Leroux, and Lereclus 2012). Recently, we found that NM-coatings acquired in the environment reduce the sensitivity of A. fumigatus spores against defensins, resulting in reduced uptake and clearance by the immune defense system and ultimately enhancing the severity of fungal lung infections (Westmeier, Solouk-Saram, et al. 2018).
Bio-efficacy and physiological effects of Eucalyptus globulus and Allium sativum essential oils against Ephestia kuehniella Zeller (Lepidoptera: Pyralidae)
Published in Toxin Reviews, 2020
Morteza Shahriari, Arash Zibaee, Leila Shamakhi, Najmeh Sahebzadeh, Diana Naseri, Hassan Hoda
Activity of lactate dehydrogenase (LDH) was assayed based on the method of King (1965). Test tube contained 1000 µl of the buffered substrate and 20 µl of the sample. To standardize volumes, 200 µl of NAD+ solution was added to the test tubes and 200 µl of water was added to the control tubes. All the test tubes were incubated for 15 min at 37 °C and then arrested with 1000 µl of color reagent (2,4-dinitrophenyl hydrazine). Incubation was prolonged for an additional 15 min and the contents were cooled to room temperature prior to add 10 ml of 0.4 M NaOH to each tube making the solutions strongly alkaline. Exactly 60 s after the addition of alkali to each tube, the intensity of color was measured at 340 nm. Specific activity was calculated by dividing absorbance with protein content in hemolymph.