Superantigenic Activity of emm3 Streptococcus pyogenes Is Abrogated by a Conserved, Naturally Occurring smeZ Mutation
Figure 1
Emm3 STSS isolates show emm-type specific differences in overall mitogenicity.
A.Human MNC proliferation response to culture supernatants from 63 Streptococcus pyogenes streptococcal toxic shock syndrome (STSS) isolates grouped by emm-type (numbers per group: emm1, n = 11; emm3, n = 12; emm12 and emm87, n = 11; emm18, n = 5; emm28, n = 7; emm89, n = 6). Negative; tissue culture media (RMPI) alone. Outliers are represented as individual circles. Representative of 2 experiments performed on different donors. B. Human MNC proliferation response to sera obtained from CD1 mice 24 hours after being infected with one of three S. pyogenes strains representing each emm-type; two mice were infected per strain. Negative; uninfected mouse serum. Proliferative response is measured as counts per minute (cpm) of tritiated-thymidine uptake. Median and 5th, 25th, 50th, 75th, and 95th centiles shown.