Comparison of the humoral and cellular immune responses between body and head lice following bacterial challenge

• Published in: Insect biochemistry and molecular biology Vol. 41; no. 5; pp. 332 - 339
• Main Authors: Kim, Ju Hyeon, Min, Jee Sun, Kang, Jae Soon, Kwon, Deok Ho, Yoon, Kyong Sup, Strycharz, Joseph, Koh, Young Ho, Pittendrigh, Barry Robert, Clark, J. Marshall, Lee, Si Hyeock
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-05-2011
• Subjects: Animals; bacteria; Bacterial challenge; Developmental stages; Escherichia coli; Female; Fluorescein-5-isothiocyanate; Gene Expression Profiling; genes; Genes, Insect - immunology; Genome - immunology; Genomes; Head; Human lice; humoral immunity; Immune response; Immune response (humoral); Immune system; Immunity, Cellular; Immunity, Humoral; immunosuppression (physiological); insects; Microscopy, Fluorescence; Pediculus - genetics; Pediculus - immunology; Pediculus - microbiology; Pediculus humanus capitis; Pediculus humanus humanus; Phagocytosis; Signal Transduction; Species Specificity; Staphylococcus aureus; Transcription; transcription (genetics); Transcription, Genetic; Vector competence; Pediculus humanus humanus; Pediculus humanus capitis; Immune response; Vector competence; Human lice; Bacterial challenge; Phagocytosis
• DOI: 10.1016/j.ibmb.2011.01.011
• EISSN: 1879-0240
• ISSN: 0965-1748

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.
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► Body lice had a significantly reduced immune response compared to head lice. ► Body lice possess fewer immune-related genes compared to other insects. ► Both body and head lice exhibited similar humoral immune responses. ► Head lice had a higher phagocytotic activity than body lice.