Apoptosis in control and AIM tonsil samples. (A) Apoptotic cells as identified by TUNEL in control tonsils are predominantly in the GCs and not in the IFZ (original magnification × 50). (B) Apoptotic cells in AIM tonsils, defined by TUNEL staining and indicated by arrows, do not costain with EBER, indicated by asterisks (original magnification × 400). (C) CD68 staining showing apoptotic cells with condensed nuclei being engulfed by macrophages (original magnification × 400). Bcl-2 expression in representative (D) control and (E) AIM tonsils is shown. Cells in the IFZ and MZ of control tonsils expressed high levels of Bcl-2, whereas GCs contained few positive cells (original magnification × 100). Results are representative of 14 AIM and 8 control tonsils investigated.