Fig. 2

Injection of oxidized low density lipoproteins (OXLDL) achieves a partial tolerization to oxLDL through clonal deletion rather than anergy.

(A–D) The oxLDL (A,B) and concanavalin A (Con A)-induced (C,D) proliferations (³H-thymidine incorporation, cpm) were analyzed on spleen cell suspensions from male (A,C) or female (B,D) mice. Cell suspensions from tolerized mice showed a significantly lower proliferative response to oxidized LDL than controls , while exhibiting a similar proliferative response towards Con A. Means ± SEM, ^*significantly different from control group, p < 0.05. (E–H) lymph node cells were pooled per group and were cultivated with (F,H) or without (E,G) interleukin-2 (IL-2), in addition to oxLDL, or ConA. The addition of IL-2 to cell suspensions from tolerized mice did not alleviate unresponsiveness, indicating that the mechanism involved in the tolerance induction is a clonal deletion. Note that addition of IL-2 to control cell suspensions increased their proliferation to oxLDL. ConA response was unaffected by IL-2 addition in both control and tolerized mouse cell suspensions. Means ± SEM of triplicate.