At enrolment, a pre-vaccination baseline dried blood spot

(DBS) on filter paper was collected by heel prick puncture for measurement of retinol-binding protein (RBP) and C-reactive protein (CRP). The filter paper was dried in up-right position overnight and stored with silica desiccant at −20 °C until analysis. At the follow-up visits, capillary KPT-330 mw blood was collected by heel puncture into a heparinised tube for whole-blood stimulation and in an EDTA-coated tube for differential counts, respectively. A DBS for RBP and CRP measurements was collected similarly to the baseline. A blood smear was microscopically inspected for malaria parasites. From collection to processing, the heparinised blood was kept at ambient temperature; the EDTA-treated blood was kept cold. All blood samples were collected by the same trained nurse and transported to the National Laboratory within 4 h. The whole blood stimulation assay was performed as previously described [6] and [7]. Briefly, the heparinised blood Histone Methyltransferase inhibitor was diluted 1:10 with RPMI-1640 medium (Invitrogen, Breda, Netherlands) supplemented with 2 mM glutamate, 1 mM pyruvate, 100 IU penicillin and 100 μg/ml streptomycin, and cultured at 37 °C with 5% CO2, stimulated with

lipopolysaccharide (LPS) (1 ng/ml, Sigma-Aldrich, Zwijndrecht, Netherlands) [a Toll-like receptor (TLR)4 agonist], (S)-(2,3-bis(palmitoyloxy)-(2-RS)-propyl)-N-palmitoyl-(R)-Cys-(S)-Ser-(S)-Lys4-OH,trihydrochloride (Pam3cys) (100 ng/ml, Cayla-InvivoGen Europe, Toulouse, France) [a TLR2 agonist], antigen purified protein derivative (PPD) of Mycobacterium tuberculosis (10 μg/ml, Statens Serum Institut, Copenhagen, Denmark), BCG (Statens Serum Institut, final concentration 1:100), trivalent OPV (final concentration 1:100) or phytohaemagglutinin (PHA) (2 μg/ml, Welcome Diagnostics, Dartford, UK) [a T cell mitogen]. Tryptophan synthase Controls were medium alone cultures (referred as medium). Supernatants were collected after one day (for LPS, Pam3cys and medium1) or three days

of incubation (for PPD, BCG, OPV, PHA, poly I:C and medium3) and stored below minus 40 °C until cytokine measurements. Cytokine concentrations in supernatants were analysed at Statens Serum Institut, Copenhagen, Denmark. IL-10 and TNF-α from day 1 supernatants stimulated with LPS and Pam3cys, and IL-2, IL-5, IL-10, TNF-α and IFN-γ from day 3 supernatants stimulated with PPD, BCG, OPV, PHA and poly I:C were analysed using Luminex cytokine kit and buffer reagent kit (BioSource, Camarillo, CA, USA) on a Luminex-200 cytometer (Luminex Corporation, Austin, TX, USA) equipped with Bio-Plex Manager version 5.0 (Bio-Rad, Hercules, CA,USA). The assay was performed according to the manufacturer’s instructions with slight modifications. Briefly, assays were performed in a 96-well U plate (NUNC, Roskilde, Denmark) at room temperature.