CD4 and infection: To investigate whether depletion of specific T-cell subsets influenced the dynamics of other non-depleted immune cell populations (CD4+, CD8+, and WC1+/γδ TcR+ T cells and CD21+ B cells) during BTV infection in sheep, we performed immunophenotyping of ovine whole blood at regular intervals during infection and assessed immune cell populations by flow cytometry (Figures 6A–D).