Longitudinal single-cell transcriptomics of monocytes, Tfh and gd Tcells following a control human malaria infection.
Malaria infection drives tolerogenic cell responses which protects from high inflammation and immunopathogenesis but reduces  parasite control and adaptive immunity. Here, we comprehensively map responses across innate and adaptive cells. The results of this Controlled Human Malaria Infection study are presented in three independent publications. Blood samples from 4 donors were collected prior to infection (day 0), at peak infection (day 8) and 14 or 15 and 27-36 days (end of study, EOS) after inoculation (in analyses these time points are grouped as 0, 8, 14/15 and EOS).  Participants were healthy malaria naïve adults with no prior exposure to malaria or residence in malaria-endemic regions.  For trials NCT02867059, NCT02783833, NCT02431637 all participants received the same study drug (no-randomization) and 3D7-strain parasites. For NCT02431650, participants were randomized 1:1 to receive study drug or control and 3D7-strain parasites. Samples used here were from samples opportunistically collected from volunteers who consented to donate blood for immunological studies within the parent clinical trial. As such, no sample size estimation was performed for this immunology study. Overall design: In brief, healthy malaria naïve adults with no prior exposure to malaria or residence in malaria-endemic regions underwent CHMI with 2800 viable P. falciparum parasitized RBCs, and peripheral parasitaemia was measured at least daily by qPCR as described previously ?(53)?. Participants were treated with antimalarial drugs at day 8 of infection when parasitaemia reaches approximately 20,000 parasites/ml. PBMCs were isolated by Ficoll-Paque (Sigma, USA) density gradient centrifugation, isolated PBMCs were cryopreserved in 10% DMSO/FBS. Monocytes, Tfh and GD-T cells from 4 individuals with P. falciparum infection were collected at day of infection (day 0), peak parasitaemia and before treatment at (day8), and day 16 and 36 days post-infection. PBMCs were isolated by Fluorescence-activated cell sorting (FACS) and analysed using droplet-based scRNAseq.”