Figure 2

Distinct roles for CD4⁺ T cell subpopulations in chronic Friend Retrovirus infection. During chronic infection, effector CD8⁺ T cell responses are suppressed by regulatory T cells but a subpopulation of effector CD4⁺ T cells prevents virus reactivation. (Blocked lines indicate inhibition of immune responses or virus replication; the dotted line indicates that this response is suppressed during chronic infection).