CD8A and infection: During the early stage of infection at 1 dpi, the EM/CP-infected group exhibited substantial numbers of natural IEL subpopulations, including TCRαβ+CD4-CD8-, TCRαβ+CD8αα+, TCRγδ+, and TCRneg cells in the jejunum compared to the control and EM groups (Figures 4–6).