Age-related changes in immune functions in peripheral blood leukocytes from humans and in peritoneal leukocytes from mice. (A) Phagocytic Index: number of latex beads ingested per 100 human neutrophils (A.1) or mouse macrophages (A.2 and A.3); (B) Chemotaxis Index: number of phagocytes on the filter, human neutrophils (B.1) or mouse macrophages (B.2 and B.3); (C) NK cytotoxic activity (percentage of lysis of tumor cells) of human leukocytes (C.1) or mouse leukocytes (C.2 and C.3). (D) Chemotaxis Index: number of human lymphocytes on the filter (D.1) or mouse lymphocytes (D.2 and D.3); (E) Percentage of proliferation of lymphocytes in response to the mitogen Phytohaemagglutinin in the case of humans (E.1) and in response to Concanavalin A in the case of mice (E.2 and E.3). The results corresponding to peritoneal leukocytes from adult prematurely-aging mice (PAM) and non-prematurely-aging mice (NPAM) are shown in A.3, B.3, C.3, D.3, and E.3. A: Adult; M: Mature; O: Old; L: Long-Lived; a: P < 0.05; aa: P < 0.01; aaa: P < 0.001 with respect to the value in adults. b: P < 0.05; bb: P < 0.01; bbb: P < 0.001 with respect to the value in mature individuals. c: P < 0.05; cc: P < 0.01; ccc: P < 0.001 with respect to the value in old subjects. d: P < 0.05; dd: P < 0.01; ddd: P < 0.001 with respect to the value in NPAM.