The link between IL-17 and neutrophil recruitment [15], [16], as well as the observation suggesting a role for B cells and humoral immunity in modulating Th1 response in TB [2] and Th17 response in autoimmune diseases [41], [42], [43], [44], [45] prompted us to examine whether the neutrophilia observed in the lungs of μMT mice could be due to an aberrant Th17/IL-17 response as a result of B cell-deficiency. This evidence concerns the gene IL17A and B cell deficiency.