ITGAM and persistent truncus arteriosus: Moreover, microbiota depletion resulted in a blunted T cell activation in the mediastinal LNs, and infiltration of T cells in the heart, something we have previously described as being critical for the development of cardiac fibrosis and systolic dysfunction in response to TAC.19–22 CD11b+ myeloid cells, which precede T cell infiltration in TAC,36 were also decreased, suggesting that microbes shape innate and adaptive immune responses in the onset of TAC.