Structural characterization of tick cement cones collected from in vivo and artificial membrane blood-fed Lone Star ticks (Amblyomma americanum).
The Lone Star tick, Amblyomma americanum, is endemic to the southeastern United States and capable of transmitting pathogenic diseases and causing non-pathogenic conditions. To remain firmly attached to the host, the tick secretes a proteinaceous matrix termed the cement cone which hardens around the tick's mouthparts to assist in the attachment of the tick as well as to protect the mouthparts from the host immune system. Cement cones collected from ticks on a host are commonly contaminated with host skin and hair making analysis of the cone difficult. To reduce the contamination found in the cement cone, we have adapted an artificial membrane feeding system used to feed long mouthpart ticks. Cones collected from in vivo and membrane fed ticks are analyzed to determine changes in the cone morphology. Comparisons of the cement cones using light microscopy shows similar structures and color however using scanning electron microscopy the cones have drastically different structures. The in vivo cones contain fibrils, sheets, and are heavily textured whereas cones from membrane fed ticks are remarkably smooth with no distinct structures. Analysis of the secondary protein structures using FTIR-ATR show both in vivo and membrane fed cement cones contain β sheets but only in vivo cement cones contain helical protein structures. Additionally, proteomic analysis using LC-MS/MS identifies many proteins including glycine rich proteins, metalloproteases, and protease inhibitors. Proteomic analysis of the cones identified both secreted and non-secreted tick proteins. Artificial membrane feeding is a suitable model for increased collection of cement cones for proteomic analysis however, structurally there are significant differences.
Department of Biological Sciences, University of Southern Mississippi, Hattiesburg, MS 39406, USA.
Rebekah
R
Bullard
Department of Biological Sciences, University of Southern Mississippi, Hattiesburg, MS 39406, USA.
Paige
P
Allen
Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD 20892, USA.
Chien-Chung
CC
Chao
School of Polymers and High Performance Materials, University of Southern Mississippi, Hattiesburg, MS 39406, USA.
Jessica
J
Douglas
School of Polymers and High Performance Materials, University of Southern Mississippi, Hattiesburg, MS 39406, USA.
Pradipta
P
Das
School of Polymers and High Performance Materials, University of Southern Mississippi, Hattiesburg, MS 39406, USA.
Sarah E
SE
Morgan
Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD 20892, USA.
Wei-Mei
WM
Ching
Department of Biological Sciences, University of Southern Mississippi, Hattiesburg, MS 39406, USA. Electronic address: Shahid.Karim@usm.edu.
Shahid
S
Karim
D000818:Animals; D060829:Arthropod Proteins / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism; D001769:Blood; D005247:Feeding Behavior; D005260:Female; D026863:Ixodidae / Q000033:anatomy & histology / Q000737:chemistry* / Q000502:physiology; D008297:Male; D008567:Membranes, Artificial; D045726:Metalloproteases / Q000032:analysis; D008855:Microscopy, Electron, Scanning; D009055:Mouth / Q000378:metabolism; D011480:Protease Inhibitors / Q000032:analysis; D040901:Proteomics; D053719:Tandem Mass Spectrometry
D060829:Arthropod Proteins; D008567:Membranes, Artificial; D011480:Protease Inhibitors; D045726:Metalloproteases
Amblyomma americanum; Artificial membrane feeding; Cement proteins; Proteome