tb PPD in stimulated 6-day whole blood cultures, while unvaccinated infants do not make a detectable IFNγ response [6]. Though the TH1 cytokine IFNγ plays an important part in immunity to TB [7], [8] and [9], it is not sufficient on its own to protect against TB, and other cytokines, such as TNFα, also play a role in immunity to TB [5]. This study Vorinostat was designed to identify which cytokines other than IFNγ are induced following BCG vaccination in UK infants, and the associations between the various cytokines produced. The Multiplex assay has the advantage of being more sensitive than ELISA, and to be able to measure multiple

cytokines in a small blood sample, and so is appropriate for studies of infants. The study aims to characterise cytokine patterns induced following vaccination against tuberculosis, which could, in turn, suggest promising candidates for biomarkers of protection for clinical trials of new TB vaccines. Twenty-eight Caucasian infants who were born in the UK, and who were part of our BCG vaccination study in which we had measured IFNγ in supernatants 3 months post-BCG vaccination Selisistat by ELISA [6] were selected for additional cytokine analysis. Of these

infants, 19 had been BCG vaccinated between 5 and 10 weeks of age (mean 7 weeks), and 9 had not received BCG. Approval for the study was given by the Redbridge and Waltham Forest Health Authority Local Research Ethics Committee, and the Ethics Committee of the London School of Hygiene & Tropical Medicine. Whole blood assays and ELISAs for IFNγ were carried out as previously described [10] and [11]. Heparinised whole blood was diluted 1 in 10 and

cultured on the day of collection with the M.tb PPD (Statens Serum Institut, Copenhagen (SSI), RT49, lot 204) at a concentration of 5 μg/ml or medium alone (unstimulated) as the negative control. PHA-P was used as a positive control; IFNγ from PHA-P cultures PAK6 was measured by ELISA [6] but were not included in the Multiplex assay. Cultures were incubated at 37 °C with 5% CO2; supernatants were harvested on day 6 and stored at −70 °C until assayed for IFNγ in single 100 μl samples by quantitative ELISA or for 21 cytokines and chemokines in single 25 μl samples by Multiplex assay. The following 21 cytokines and chemokines were measured simultaneously in supernatants using a human cytokine Lincoplex premixed kit according to the manufacturer’s instructions (cat #HCYTO-60K-PMX, Linco Research Inc., St. Charles Missouri, USA): IL-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p70, IL-13, IL-15, IL-17, IL-1α, IFNγ, G-CSF, GM-CSF, TNFα, Eotaxin, MCP-1, MIP-1α and IP-10. Unstimulated, M.tb PPD stimulated and 1 in 10 diluted M.tb PPD stimulated samples were read on the Biorad Luminex reader using Bioplex manager 4.1 software. For each cytokine the standard curve ran from 3.2 to 10,000 pg/ml.