Byrum

Janie Rae Byrum, Matthew Fricke, Justyna Tafoya, Melanie Moses, Judy L Cannon

Quantitating dendritic cell clustering in the lymph node

The efficiency of the T cell search for antigen presented by dendritic cells (DCs) in lymph nodes (LNs) is a determinant of the overall timing of the T cell immune response to infection. While there is suggestion that DCs are clustered in LNs, there has been little quantitative analysis done to precisely analyze DC positioning in LNs. We present the quantitation of murine DC motility, surface area, and volume in the lymph node. We also use computational analysis of 2 photon microscopy images of explanted murine lymph nodes from CD11c-YFP mice to determine the degree of clustered-ness of DCs. Our analysis indicates a degree of DC clustering within the lymph node. Previously our lab identified sites in the lymph node visited with greater frequency by T cells than would be expected by random motility. We hypothesize such sites demonstrate that DC clusters may actively attract T cells. Elucidating whether T cell motility around DC clusters is distinctive from T cell motility in areas where DCs are non-clustered will help decipher T cell search strategy and the timing of the adaptive immune response.