Regulation of Antimicrobial Peptide Genes in Insects by the Toll Pathway and NF-kB Transcription Factors
Abstract
Insects lack adaptive immunity and solely rely on innate immunity to combat
pathogens. Innate immunity in dipteran and lepidopteran insects mainly depends on two
canonical pathways, the Toll pathway that provides protection against Gram-positive
bacteria, fungi and viruses, and the Immune Deficiency (IMD) pathway, which
provides protection against Gram-negative bacteria. Insect innate immune responses
can be categorized broadly into two types: cellular and humoral. The cellular responses
include insect blood cells known as hemocytes that are involved in phagocytosis,
nodulation, encapsulation, and wound healing. The humoral immune responses, on the
other hand include production of antimicrobial peptides (AMPs) by fat body, which is
equivalent to mammalian liver, prophenoloxidase, lectins and compliment-like factors.
Chapter 1 talks about the important features of insect innate immunity. Chapter 2
discusses the role of the Toll-7 receptor in Drosophila melanogaster against bacterial
and viral infections. Chapter 3 depicts a new constitutively active short relish isoform
lacking inhibitory domain in D. melanogaster that functions towards providing
protection to low load of infection. Chapter 4 illustrates the role of a transcription factor
in Manduca sexta known as Forkhead (MsFkh) that is involved in innate immunity.
Lastly, Chapter 5 will summarize all data and foretell future perspectives.
Table of Contents
Introduction to insect innate immunity -- Multiple toll-spatzle pathways in drosophila melanogaster innate immunity -- NF-kB transcription factors cooperatively regulate antimicrobial peptide genes in drosophila melanogaster -- Forkhead transcription factor regulates antimicrobial peptide genes in the tobacco hornworm manduca sexta -- Research summary and future direction
Degree
Ph.D.