Castration significantly increases the naive population. Naive and memory splenic cells as denoted by CD62L^hiCD44⁻ and CD62L^loCD44^hi, respectively, were analyzed by flow cytometry. (A,B) Results indicated a significant increase in proportion and number of naive cells in the Cx/BMT group, (C,D) and a significant reduction in the proportion of memory cells. (E) In contrast to BMT only–treated mice, Cx/BMT-treated mice displayed a significant delay in developing severe EAE. (F) Androgen ablation did not enhance a TH-1 or TH-17 immune response as assayed by cytometric bead analysis of MOG_35-55–stimulated splenocyte supernatant. Results are expressed as mean plus or minus SEM of 5 to 10 mice from 2 or more independent experiments. **P < .01 versus BMT only; *P < .01 versus BMT only; ∧P < .05 BMT only versus Cx/BMT; and ∧∧P < .01 BMT only versus EAE untreated.