Effect of LPG galactosylation pattern on <i>Leishmania</i> survival in “selective” <i>Phlebotomus papatasi PpapJ</i> sand flies.

aThe L. major (FV1, LV39c5, SD) and L. donovani (Ld) wild-type (“WT”) and transfectant lines used in experimental PpapJ laboratory infections are described in the text, with supporting data in Tables S1 to S3 and Methods. b“LPG-scGal modification frequency” is the percentage of modified PG repeats bearing terminal βGal side chains present in purified procyclic promastigote LPG samples. cThe average length of βGal side chains in purified procyclic promastigote LPG, or “avg. scGal chain length”, was calculated by multiplying “LPG-scGal modification frequency” × “mean scGal chain length”, using data in Table S1. dLPG galactosylation patterns, or “scGal-LPG PAMPs”, were classified by the average length of LPG βGal side chains (column 3): ‘null’, <0.1 βGal; ‘mono’, 0.7–1.3 βGals; ‘oligo’, 1.9 βGals; ‘poly’, ≥3 βGals. e“% infected flies” is the average percentage (±SEM) of Leishmania-infected PpapJ flies post-blood meal expulsion, calculated from data in Figs. 1, 2, 4 and Tables S2, S3. Most lines were examined in two independent infections, except for WT FV1 (6 infections), and WT SD and Ld-cSCG3 (1 experiment each, “*”). f“Relative parasites/midgut” is the average number (± SEM) of parasites per midgut post-blood meal expulsion calculated relative to WT FV1 = 100, using data in Figs. 1, 2, 4, and Tables S2, S3. The average of two or more independent experiments is shown, except for WT SD and Ld-cSCG3 (1 experiment each, “*”). ∧Since WT FV1 was not included in this experiment, and P. argentipes PargIN is the natural vector for Ld parasites, the number of Ld-cSCG3 promastigotes was calculated relative to Ld-vector-infected PargIN flies. gThe “average relative survival” of parasites post blood-meal expulsion was calculated by multiplying “% infected flies” × “relative parasites/midgut” (column 7× column 8). The average (± SEM) of two independent experiments is shown, except for WT FV1 (6 experiments) and SD and Ld-cSCG3 (1 experiment each, “*”). ∧Since WT FV1 was not included in this experiment, and PargIN is the natural vector for Ld parasites, survival is relative to control Ld-vector-infected PargIN flies.