CD4 and infection: In the late infection, studies using unseparated CD4+ and CD8+ T cells showed a reduction in the frequency of T cells expressing Vβ14 in the spleen and in nonlymphoid organs such as skeletal muscle and spinal cord, while the frequency of T cells expressing Vβ6 and Vβ8.1, 8.2 was elevated in the spleen and lymph node [34,40] (Fig 5).