title: Comparative Analysis of Salivary Gland Proteomes of Two Glossina Species that Exhibit Differential Hytrosavirus Pathologies.
abstract: Glossina pallidipes salivary gland hypertrophy virus (GpSGHV; family Hytrosaviridae) is a dsDNA virus exclusively pathogenic to tsetse flies (Diptera; Glossinidae). The 190 kb GpSGHV genome contains 160 open reading frames and encodes more than 60 confirmed proteins. The asymptomatic GpSGHV infection in flies can convert to symptomatic infection that is characterized by overt salivary gland hypertrophy (SGH). Flies with SGH show reduced general fitness and reproductive dysfunction. Although the occurrence of SGH is an exception rather than the rule, G. pallidipes is thought to be the most susceptible to expression of overt SGH symptoms compared to other Glossina species that are largely asymptomatic. Although Glossina salivary glands (SGs) play an essential role in GpSGHV transmission, the functions of the salivary components during the virus infection are poorly understood. In this study, we used mass spectrometry to study SG proteomes of G. pallidipes and G. m. morsitans, two Glossina model species that exhibit differential GpSGHV pathologies (high and low incidence of SGH, respectively). A total of 540 host proteins were identified, of which 23 and 9 proteins were significantly up- and down-regulated, respectively, in G. pallidipes compared to G. m. morsitans. Whereas 58 GpSGHV proteins were detected in G. pallidipes F1 progenies, only 5 viral proteins were detected in G. m. morsitans. Unlike in G. pallidipes, qPCR assay did not show any significant increase in virus titers in G. m. morsitans F1 progenies, confirming that G. m. morsitans is less susceptible to GpSGHV infection and replication compared to G. pallidipes. Based on our results, we speculate that in the case of G. pallidipes, GpSGHV employs a repertoire of host intracellular signaling pathways for successful infection. In the case of G. m. morsitans, antiviral responses appeared to be dominant. These results are useful for designing additional tools to investigate the Glossina-GpSGHV interactions.
authors.affiliation: Biotechnology Research Institute, Kenya Agricultural and Livestock Research OrganizationNairobi, Kenya; Insect Pest Control Laboratory, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, International Atomic Energy AgencyVienna, Austria; Laboratory of Virology, Wageningen UniversityWageningen, Netherlands.
authors.forename: Henry M
authors.initials: HM
authors.lastname: Kariithi
authors.affiliation: Department of Medical Microbiology, Acıbadem University İstanbul, Turkey.
authors.forename: İkbal Agah
authors.initials: İA
authors.lastname: İnce
authors.affiliation: Laboratory of Biochemistry, Wageningen University Wageningen, Netherlands.
authors.forename: Sjef
authors.initials: S
authors.lastname: Boeren
authors.affiliation: South African National Bioinformatics Institute, University of the Western Cape Cape Town, South Africa.
authors.forename: Edwin K
authors.initials: EK
authors.lastname: Murungi
authors.affiliation: Insect Pest Control Laboratory, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, International Atomic Energy AgencyVienna, Austria; Laboratory of Virology, Wageningen UniversityWageningen, Netherlands.
authors.forename: Irene K
authors.initials: IK
authors.lastname: Meki
authors.affiliation: Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology Nairobi, Kenya.
authors.forename: Everlyne A
authors.initials: EA
authors.lastname: Otieno
authors.affiliation: Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology Nairobi, Kenya.
authors.forename: Steven R G
authors.initials: SR
authors.lastname: Nyanjom
authors.affiliation: Laboratory of Virology, Wageningen University Wageningen, Netherlands.
authors.forename: Monique M
authors.initials: MM
authors.lastname: van Oers
authors.affiliation: Laboratory of Virology, Wageningen University Wageningen, Netherlands.
authors.forename: Just M
authors.initials: JM
authors.lastname: Vlak
authors.affiliation: Insect Pest Control Laboratory, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency Vienna, Austria.
authors.forename: Adly M M
authors.initials: AM
authors.lastname: Abd-Alla
keywords: Hytrosaviridae; LC-MS/MS; SGH syndrome; asymptomatic infection; hypertrophy; pathogenesis; unfolded protein response