The effect of selected immunostimulants on hemocytes of the false black widow Steatoda grossa (Theridiidae) spiders under chronic exposition to cadmium

• Published in: Comparative biochemistry and physiology. Toxicology & pharmacology 2022-02, Vol.252, p.109221-109221, Article 109221
• Main Authors: Wiśniewska, Kamila, Rost-Roszkowska, Magdalena, Homa, Joanna, Kasperkiewicz, Katarzyna, Surmiak-Stalmach, Kinga, Szulińska, Elżbieta, Wilczek, Grażyna
• Format: Article
• Language: English
• Subjects: Adjuvants, Immunologic - pharmacology; Animals; Cadmium; Cadmium - toxicity; Degenerative changes; Hemocytes - drug effects; Immunostimulants; Spiders - cytology; Spiders hemocytes
• ISSN: 1532-0456; 1878-1659
• DOI: 10.1016/j.cbpc.2021.109221

The aim of this study was to analyze whether, and to what extent, long–term exposure to cadmium, administered in sublethal concentrations by the oral route, caused changes in the immune potential of hemocytes in adult female Steatoda grossa spiders. We used artificial and natural immunostimulants, namely phorbol 12–myristate 13–acetate (PMA) and bacterial cell suspension based on Gram–positive (G+, Staphylococcus aureus) and Gram–negative (G−, Pseudomonas fluorescens) bacteria, to compare the status of hemocytes in nonstimulated individuals and those subjected to immunostimulation. After cadmium exposure, the percentage of small nongranular hemocytes in response to G+ cell suspension and PMA mitogen was decreased. Furthermore, in the cadmium–intoxicated spiders the percentage of plasmatocytes after immunostimulation remained lower compared to the complementary control group. Exposure to cadmium also induced several degenerative changes, including typical apoptotic and necrotic changes, in the analyzed types of cells. Immunostimulation by PMA mitogen and G+ bacterial suspension resulted in an increase in the number of cisterns in the rough endoplasmic reticulum of granulocytes, in both the control group and cadmium–treated individuals. These changes were accompanied with a low level of metallothioneins in hemolymph. Chronic cadmium exposure may significantly weaken the immune defense system of spiders during infections. [Display omitted] •Sublethal concentrations of cadmium change the proportion of different types of hemocytes in spider hemolymph.•Long-term exposure to cadmium administered through the digestive tract enhances degenerative changes in spider hemocytes.•Chronic cadmium exposure may weaken the immune defense system of spiders during infections.•Synthesis of metallothionein's in the midgut glands of spiders plays a protective role for the exposure of hemocytes to excess metal concentrations