title: Comparison of the humoral and cellular immune responses between body and head lice following bacterial challenge.
abstract: The differences in the immune response between body lice, Pediculus humanus humanus, and head lice, Pediculus humanus capitis, were investigated initially by measuring the proliferation rates of two model bacteria, a Gram-positive Staphylococcus aureus and a Gram-negative Escherichia coli, following challenge by injection. Body lice showed a significantly reduced immune response compared to head lice particularly to E. coli at the early stage of the immune challenge. Annotation of the body louse genome identified substantially fewer immune-related genes compared with other insects. Nevertheless, all required genetic components of the major immune pathways, except for the immune deficiency (Imd) pathway, are still retained in the body louse genome. Transcriptional profiling of representative genes involved in the humoral immune response, following bacterial challenge, revealed that both body and head lice, regardless of their developmental stages, exhibited an increased immune response to S. aureus but little to E. coli. Head lice, however, exhibited a significantly higher phagocytotic activity against E. coli than body lice, whereas the phagocytosis against S. aureus differed only slightly between body and head lice. These findings suggest that the greater immune response in head lice against E. coli is largely due to enhanced phagocytosis and not due to differences in the humoral immune response. The reduced phagocytotic activity in body lice could be responsible, in part, for their increased vector competence.
authors.affiliation: Department of Agricultural Biotechnology, Seoul National University, 151-921 Seoul, Republic of Korea.
authors.forename: Ju Hyeon
authors.initials: JH
authors.lastname: Kim
authors.forename: Jee Sun
authors.initials: JS
authors.lastname: Min
authors.forename: Jae Soon
authors.initials: JS
authors.lastname: Kang
authors.forename: Deok Ho
authors.initials: DH
authors.lastname: Kwon
authors.forename: Kyong Sup
authors.initials: KS
authors.lastname: Yoon
authors.forename: Joseph
authors.initials: J
authors.lastname: Strycharz
authors.forename: Young Ho
authors.initials: YH
authors.lastname: Koh
authors.forename: Barry Robert
authors.initials: BR
authors.lastname: Pittendrigh
authors.forename: J Marshall
authors.initials: JM
authors.lastname: Clark
authors.forename: Si Hyeock
authors.initials: SH
authors.lastname: Lee
mesh_terms: D000818:Animals; D004926:Escherichia coli; D005260:Female; D016650:Fluorescein-5-isothiocyanate; D020869:Gene Expression Profiling; D017344:Genes, Insect / Q000276:immunology*; D016678:Genome / Q000276:immunology; D007111:Immunity, Cellular; D056724:Immunity, Humoral; D008856:Microscopy, Fluorescence; D010374:Pediculus / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D010587:Phagocytosis; D015398:Signal Transduction; D013045:Species Specificity; D013211:Staphylococcus aureus; D014158:Transcription, Genetic
chemical_list: D016650:Fluorescein-5-isothiocyanate