To examine CD4+ T lymphocytes in the periphery, spleens and lumbar LNs were collected and processed for intracellular flow cytometric analysis. CD4+ T lymphocytes were first identified (the CD45+CD3+CD4+ population), and then the expression of T-bet (transcription factor found in Th1, and not Th2, cells), GATA-3 (transcription factor found in Th2, and not Th1, cells), IFN-γ (one of the signature cytokines produced by Th1 cells), and IL-4 (one of the signature cytokines produced by Th2 cells) were examined within the CD4+ T lymphocytes (Figure 1A). Consistent with our previous findings regarding peripheral responses post-L5Tx [4], no significant differences in the percentages of T-bet+, GATA-3+, IFN-γ+, or IL-4+ CD4+ T lymphocytes were detected in either spleen or lumbar LNs when the naive, L5Tx and sham groups were compared (Figure 1B and 1C, one-way ANOVA, p>0.05 for all data sets within each graph). Since signs of splenic CD4+ T lymphocyte activation were previously observed at day 3 post-surgery [4], similar experiments were performed to examine splenic CD4+ T lymphocytes at day 3 post-surgery. However, no significant differences were detected in any of the above populations assessed (data not shown). Thus, the data indicate a lack of a significant Th1- or Th2-dominant response in the periphery after either L5Tx or sham surgery.