Figure 6. In vivo expansion of M1 MΦs, M2 MΦs, and Th17 cells in the spleens of host mice with mycobacterial infection.

(a–c) Histopathologic features of the spleen of MAC-infected host mice. (a) The thin sections of spleens from uninfected and infected mice (2 weeks after infection) were subjected to HE staining. (b), (c) The thin sections were stained with either rabbit anti-NOS2 Ab (b) or anti-Arg-1 Ab (c), followed by staining with Fluor 488-conjugated secondary Ab, and subjected to confocal microscopy as described in Experimental Procedures. (d) The thin sections of spleen of infected mice were stained for acid-fast bacilli by the Ziehl-Neelsen staining method. (e–g) Splenic T cells from MAC-infected mice (2 weeks after infection; Inf-T cells) and uninfected mice (nT cells) were stimulated with anti-CD3 and anti-CD28 Abs and cultured under either the Th17 polarizing condition or non-Th17 skewing condition. After 5-day cultivation, culture fluids and cultured T cells were harvested and subjected to measurement of IL-17 concentrations (e) and intracellular expressions of IL-17A (f) and RORγt (g), as described in Fig. 3 and Fig. 2, respectively. Data are representative of multiple experiments; error bars, s.e.m.; *p < 0.01 (Bonferroni's multiple t-test).