DC Subsets in BCG Infection Figure 8. Intranasal adoptive transfer of iCD8+DC, but not iCD82DC, enhanced IFN- c production by T cell. Mice were adoptively transferred i.n. with iCD8+DC or iCD82DC subsets followed by the challenge with BCG through i.n route as described in Materials and Methods. Draining lymph nodes was isolated aseptically and single cell suspension was prepared in cold staining buffer. Cells were co-stained with FITC-anti CD3e, PE-anti CD4, PerCP-anti CD8 Abs and stained for intracellular IFN-c using allophycocyanin -conjugated anti-IFNc Ab as described in Materials and Methods. Cells were gated on CD3e+T cells, CD3e+CD4+T cell and CD3e+CD8+T cell respectively and the percentage of positive cells for IFN-c is indicated in upper right corner (A). Pooled data in each group are shown as mean6SD (B). One representative experiment of two independent experiments is shown. *p,0.05; **, p,0.01. doi:10.1371/journal.pone.0009281.g008 infection[39]. Our data showed that adoptive transfer iCD82 DC had no significant effect on BCG loads in the lung and liver following challenge infection. However, histological analysis showed that the inflammation in the lung and liver tissues of iCD82 DC recipients was not only much heavier than the iCD8+ DC recipients but also more severe than the mice without previous DC transfer. Typical multinucleate giant cells were found around the granulomas in mice without DC transfer. However, the iCD82 DC recipients showed more diffused inflammation. Granuloma formation is an important way for the host to control mycobacterial infection, although its efficiency is not absolute. The most successful control of infection would lead to resolution of inflammation without granuloma formation. However, the lack of granuloma formation with diffused inflammation observed in the iCD82 DC recipients implies a lack of efficient control for the infection and the development of more severe pathological inflammation. The highest level of inflammatory cytokines/chemokine (IL-6, MIP-1a, TNF-a) in the iCD82 DC recipients confirms the severe inflammation in these mice. Since granuloma in mycobacterial infection is a type-1 granuloma that is promoted by IFNc and inhibited by IL-10, the higher IL-10 production by iCD82 DC may be the basis for the significantly reduced granuloma formation in its recipients. It should be noted, however, that the challenge infection used in the study is BCG instead of virulent Mtb strains which are the real PLoS ONE | www.plosone.org 10 February 2010 | Volume 5 | Issue 2 | e9281