SALP16, a gene induced in Ixodes scapularis salivary glands during tick feeding.
Guinea pigs infested with Ixodes scapularis acquire antibody-mediated resistance to tick bites, a phenomenon known as tick-immunity. An I. scapularis salivary gland cDNA expression library was therefore probed with sera from tick-immune guinea pigs to identify antigens that elicit humoral responses in the host. Sera from sensitized guinea pigs strongly recognized 3 of 4,500 library clones in an initial screening. The open reading frames of all 3 clones encoded a putative 16.4-kD acidic protein, designated Salp16, with an N-terminal signal sequence and signal peptidase cleavage sites specific for secretory proteins. The salp16 mRNA and Salp16 protein were detected in the salivary glands of engorged, but not unfed, nymphal and adult ticks, and Salp16 was also found in the saliva of engorged ticks. Immunization with recombinant Salp16 induced high antibody titers in guinea pigs, but did not elicit tick-immunity. Salp16 is the first feeding inducible gene that has been cloned from L. scapularis. Molecular characterization of I. scapularis salivary antigens that are induced upon tick feeding should help to facilitate our understanding of tick-host interactions.
Das
S
S
Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520-8031, USA.
Marcantonio
N
N
Deponte
K
K
Telford
S R
SR
Anderson
J F
JF
Kantor
F S
FS
Fikrig
E
E
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay; D005247:Feeding Behavior / Q000502:physiology; D005260:Female; D005786:Gene Expression Regulation; D015723:Gene Library; D006168:Guinea Pigs; D018884:Ixodes / Q000737:chemistry / Q000235:genetics*; D051379:Mice; D008809:Mice, Inbred C3H; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012313:RNA / Q000737:chemistry / Q000302:isolation & purification; D019105:Random Amplified Polymorphic DNA Technique; D011994:Recombinant Proteins / Q000737:chemistry; D012469:Salivary Glands / Q000378:metabolism; D012471:Salivary Proteins and Peptides / Q000737:chemistry / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013984:Tick Infestations / Q000276:immunology*
D011994:Recombinant Proteins; D012471:Salivary Proteins and Peptides; C406843:Salp16 protein, Ixodes scapularis; D012313:RNA