a, Immunoblot analysis of IL-1β in culture supernatants (Sup) and lysates (Lys) of WT (Mefv+/+) or Mefv−/− mouse BMDMs primed with LPS and treated with either C3 toxin or ATP, or infected with WT or ΔyopM Y. pestis strains at MOI 10. b, Immunoblot analysis of 14-3-3 in proteins immunoprecipitated (IP) with antibody to human pyrin from lysates (Lys) of control CD14+ monocytes treated with C3 toxin, Y. pestis, or both C3 toxin and Y. pestis at MOI 10. Data are representative of three independent experiments with similar results (a and b). c, IL-1β measurements of culture supernatants of retroviral transduced U937 cells, expressing WT or indicated mutant pyrin proteins, differentiated with PMA and infected with indicated MOI of WT Y. pestis. Results are presented as mean ± s.e.m., for n=5 independent biological replicates. MOCK, vector control.