Table 1.
Streptococcal strains used in this study.
Figure 1.
Distribution of antigen-specific memory Th subsets after exposure to streptococcal antigens by autologous monocytes.
Raw data of a T cell library of a representative donor screened for reactivity for a panel of ten streptococci. Antigen-specific activity was quantified as a response in increased T cell proliferation determined by thymidine incorporation. Each graph represents the screening of reactivity of one T cell subset to the pane00l of bacteria and each circle represents one well of the respective subset. The dashed line represents lowest counts per minute (CPM) values included in the analysis.
Figure 2.
Subset distribution of CD4+ memory T cells in response to oropharyngeal-associated streptococcal bacteria.
Distribution of single donor (circles) (N = 3–6) and mean (bars) frequencies of CD4+ memory T cells among the CCR6− Th1, CCR6+ Th1, Th2, Th17 and Th22 subsets reactive to streptococcal antigens. Data are presented as reactive cells per one million cells in the respective subsets. Open bars: S. mitis; closed bars: S. pneumoniae; hatched bars: S. salivarius. 62644: S. mitis CCUG 62644; 62641: S. mitis CCUG 62641; 31611T: S. mitis CCUG 31611T; 31611T Δcps: S. mitis CCUG 31611T capsule deletion mutant; 31611T TIGR4: S. mitis CCUG 31611T mutant with capsule from S. pneumoniae TIGR4; D39: S. pneumoniae D39; Sero 1: clinical isolate of S. pneumoniae serotype 1; TIGR4: S. pneumoniae TIGR4; TIGR4 Δcps: S. pneumoniae TIGR4 capsule deletion mutant; JIM8777: S. salivarius JIM8777.
Figure 3.
Response of TT-specific Th17 memory cell clones to native antigen in combination with bacterial cells.
Tetanus toxoid (TT)-specific CD4+ Th17 memory T cell clones were co-cultured with autologous monocytes and either TT alone or TT and S. mitis 31611T or S. pneumoniae TIGR4 (MOI: 100:1) for 3 d before proliferation was determined by [3H]-thymidine incorporation (A: clone 1, B: clone 2).
Figure 4.
Cytokine production by CCR6+ Th1 and Th17 cells in response to streptococci.
Quantities of IFN-γ (A), IL-17A (B) and IL-22 (C) were determined in supernatants of CCR6+ Th1 and Th17 CD4+ memory T cells co-cultured for 3 d with autologous monocytes and whole cell, UV-inactivated S. mitis 31611T or S. pneumoniae TIGR4 (MOI: 100:1). Bars represent averaged values of different donors (symbols). Th17 cells secreted statistically significantly more IFN-γ, IL-17A and IL-22 when stimulated with S. pneumoniae as compared with stimulation with S. mitis (Student t test; P < 0.05; see text).
Figure 5.
Cross-reactivity of CD4+ Th17 memory T cell clones in response to oropharyngeal-associated streptococcal strains.
Th17 cells from wells initially reactive to S. mitis 62641 (A) and S. pneumoniae D39 (B) were cloned by limiting dilution and distribution of intra- and interspecies cross-reactivity was determined by thymidine incorporation. Bars represent single re-stimulation of each clone and data are presented as counts per minute (CPM).