14 – Insect Immunology

Publisher Summary This chapter discusses insect immunology. Insects do not have the adaptive immunity that defines the antigen-specific immune responses of vertebrates; insects do have innate immunity, which is comprised of cellular and humoral immune responses. The cellular innate immune responses, including phagocytosis, nodulation, and encapsulation, are mediated by hemocytes (insect blood cells). Clotting, melanin synthesis, and antimicrobial peptide (AMP) production, known collectively as humoral innate immunity, are mediated by soluble plasma proteins or fat bodies. Recent accumulated experimental data from insects, which are infected with pathogenic bacteria, fungi, parasites or viruses that specifically elicit their innate immune responses, provide strong clues that insects are useful model systems to study the innate immunity of invertebrates. As a result of drastic new technique developments in molecular cellular biology and genetics in the fruit fly, mosquito, and other large insects over the past 20 years, a dramatic explosion of knowledge of insect immunology has enabled us to understand its basic mechanisms.