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

<p>Addition of cells by transfer of lymphocytes cannot rescue iLN atrophy in <i>H</i>. <i>polygyrus</i> infected mice: Single cells LN suspension (7-10x10<sup>6</sup> cells) from uninfected C57BL/6 mice were injected into <i>H</i>. <i>polygyrus</i> 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 <i>H</i>. <i>polygyrus</i> infection <b>(A).</b> Superficial LN cellularity can be maintained by IL-7 treatment: Mice infected with <i>H</i>. <i>polygyrus</i> were treated with rIL-7 every other day for total four weeks. Weight of iLN <b>(B)</b> and cellularity of iLN <b>(C)</b> and mLN <b>(D)</b> was determined at the end of therapy. Cellularity of iLN is recovered following de-worming: C57BL/6 mice with chronic <i>H</i>. <i>polygyrus</i> were dewormed or left untreated. The reversion of changes in mLN <b>(E, F)</b> and iLN <b>(G, H)</b> cellularity was determined 10- days <b>(E, G)</b> and 21- days <b>(F, H)</b> after deworming. T cells responses to BCG infection can be corrected by deworming and recovery of cellularity: C57BL/6 mice with chronic <i>H</i>. <i>polygyrus</i> 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 1x10<sup>6</sup> CFU BCG in the footpad or mock treated with PBS. 1x10<sup>6</sup> P25- TCRTg EGFP cells were transferred <i>i</i>.<i>v</i>. to recipient mice the day before BCG injection. Popliteal LN were harvested 6 days after BCG injection and the total number of LN cells (<b>I</b>), P25-TCRTg cells tracked by EGFP (<b>J</b>) and IFNγ producing CD4+ T cells following PMA/Ionomycin restimulation <b>(K, L)</b> were determined. Data is representative of two or more experiments.</p>