Accumulation of cells in mLN after H. polygyrus infection.

Lymphocyte numbers in mLN of C57BL/6 mice with or without chronic H. polygyrus infection (A). Analysis of CD4 and CD8 T cells based on the expression of CD62L^lowCD44^hi (B, D) and CD62L^hiCD44^int/low (C, E) using FACS. Numbers (F, G) and frequency (H, I) of GFP+ lymphocyte 4 hours after transfer as determined by FACS analysis of recipient LN suspensions. Tracking of “naïve” P25-TCRTg (CD45.2) T cells in recipient LN: P25-TCRTg cells were transferred to congenic Ly 5.1 (CD45.1) prior to H. polygyrus infection. Lymph nodes were collected 21 days after H. polygyrus infection and the number of P25-TCRTg cells in mLN (J) and iLN (K) were determined by FACS. In F-I, mice received 1x10⁶ cells isolated from peripheral LN of naïve C57BL/6-GFP mice and in J and K recipient mice received 1x10⁶ LN cells isolated from P25-TCRTg EGFP mice. Influence of circulating cells on maintenance of LN cellularity: Mice treated with FTY720 throughout the course of H. polygyrus infection were sacrificed 4 weeks after infection and the cellularity of iLN (L) and mLN (M) were determined. Naive CD4+ T cell in iLN from mice with or without FTY720 treatment (N). Data is representative of two or more experiments.