Adenosine, AMP, and protein phosphatase activity in sandfly saliva.
As they probe the skin for blood, sand flies inject saliva that prevents hemostasis. Sand fly saliva also promotes leishmaniasis by suppressing immunologic functions of macrophages. Saliva of Phlebotomus papatasi, the vector of Old World cutaneous leishmaniasis, contains adenosine and AMP. We show that Ph. papatasi saliva as well as pure adenosine down-regulate the expression of the inducible nitric oxide (NO) synthase gene in activated macrophages. In addition Ph. papatasi, but not Lutzomyia longipalpis, saliva inhibits the production of NO. Taken together, these data suggest that salivary adenosine is responsible for the down-regulation of NO synthesis. Saliva of both genera Phlebotomus and Lutzomyia contains significant levels of endogenous protein phosphatase-1/2A-like activity that is heat labile, inhibitable by okadaic acid and calyculine a, and does not require divalent cations.
Katz
O
O
Department of Parasitology, The Kuvin Center for the Study of Infectious and Tropical Diseases, The Hebrew University-Hadassah Medical School, Ein Kerem, Jerusalem, Israel.
Waitumbi
J N
JN
Zer
R
R
Warburg
A
A
D000241:Adenosine / Q000032:analysis*; D000249:Adenosine Monophosphate / Q000032:analysis*; D000818:Animals; D004247:DNA / Q000737:chemistry; D015536:Down-Regulation; D004587:Electrophoresis, Agar Gel; D005260:Female; D007091:Image Processing, Computer-Assisted; D007303:Insect Vectors / Q000737:chemistry* / Q000201:enzymology / Q000469:parasitology; D018320:Leishmania major / Q000502:physiology; D016773:Leishmaniasis, Cutaneous / Q000635:transmission; D008264:Macrophages / Q000737:chemistry / Q000469:parasitology; D051379:Mice; D008809:Mice, Inbred C3H; D009569:Nitric Oxide / Q000096:biosynthesis; D019001:Nitric Oxide Synthase / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D009573:Nitrites / Q000032:analysis; D010691:Phlebotomus / Q000737:chemistry* / Q000201:enzymology / Q000469:parasitology; D010749:Phosphoprotein Phosphatases / Q000032:analysis*; D054645:Protein Phosphatase 1; D011576:Psychodidae / Q000737:chemistry* / Q000201:enzymology / Q000469:parasitology; D012313:RNA / Q000737:chemistry; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012463:Saliva / Q000737:chemistry / Q000201:enzymology
D009573:Nitrites; D009569:Nitric Oxide; D000249:Adenosine Monophosphate; D012313:RNA; D004247:DNA; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; D000241:Adenosine