Recovery of iLN cellularity and ability to mount CD4 T cell responses to BCG.

Addition of cells by transfer of lymphocytes cannot rescue iLN atrophy in H. polygyrus infected mice: Single cells LN suspension (7-10x10⁶ cells) from uninfected C57BL/6 mice were injected into H. polygyrus infected or worm free recipient mice every third day for three weeks starting the day after infection. The cellularity of popliteal LN (pLN) was determined four weeks after H. polygyrus infection (A). Superficial LN cellularity can be maintained by IL-7 treatment: Mice infected with H. polygyrus were treated with rIL-7 every other day for total four weeks. Weight of iLN (B) and cellularity of iLN (C) and mLN (D) was determined at the end of therapy. Cellularity of iLN is recovered following de-worming: C57BL/6 mice with chronic H. polygyrus were dewormed or left untreated. The reversion of changes in mLN (E, F) and iLN (G, H) cellularity was determined 10- days (E, G) and 21- days (F, H) after deworming. T cells responses to BCG infection can be corrected by deworming and recovery of cellularity: C57BL/6 mice with chronic H. polygyrus infection (Hp) were dewormed (DW) or not. Control mice (BCG and PBS) received anti-helminthic therapy at the same time. Four weeks later, mice were injected with 1x10⁶ CFU BCG in the footpad or mock treated with PBS. 1x10⁶ P25- TCRTg EGFP cells were transferred i.v. to recipient mice the day before BCG injection. Popliteal LN were harvested 6 days after BCG injection and the total number of LN cells (I), P25-TCRTg cells tracked by EGFP (J) and IFNγ producing CD4+ T cells following PMA/Ionomycin restimulation (K, L) were determined. Data is representative of two or more experiments.