CD4 and viral infectious disease: To investigate if T cell OCA-B deletion affects the ability to mount immune responses and control CNS viral infection, male Ocabfl/fl;CD4-Cre and Ocabfl/fl littermate controls were intracranially inoculated with 1500 PFU of JHMV, a β-coronavirus adapted to infect glial cells (namely, astrocytes, microglia, and oligodendrocytes) in the mouse brain and spinal cord.