Fig. 1.

Production of IFN-γ by PBMCs from SARS-recovered individuals in response to SARS-CoV S, M, E and N peptides. a PBMCs from SARS-recovered individuals (n = 21) and normal control donors (n = 7) were stimulated with or without S, M, E and N peptides for 72 h. Cells stimulated with PMA plus inomycin were used as positive controls. The culture supernatants were collected and tested for the production of IFN-γ by ELISA. All assays were performed in triplicate. Each individual point represents one result from one donor. Bars indicate mean values. *P < 0.05, **P < 0.01, NS not significant (P > 0.05). b Percentage of donors responding to S, M, E and N peptides. ++++ percentage of donors responding to four all of S, M, E and N peptides; +++ percentage of donors responding to three of S, M, E and N peptides; ++ percentage of donors responding to two of S, M, E and N peptides; + percentage of donors responding to one of S, M, E and N peptides; − percentage of donors responding to none of S, M, E and N peptides