CD4 and infection: In addition, a reduced proportion of mice showing neurological disorders was observed in Ccr5−/− recipients of CCR5+CD4+Foxp3+ Tregs, even though Ccr5−/− recipients of CCR5+CD4+Foxp3+ Tregs exhibited clinical signs starting at a similar time post-infection to those of Ccr5−/− mice and CCR5−CD4+Foxp3+ Treg recipients (Fig. 7b).