First, primary CD4+ T or B cells isolated from the blood of healthy adult humans were incubated with GBS that were either hyper-hemolytic (NCTC10/84, serotype V) or non-hemolytic (NCTC10/84ΔcylE; the non-hemolytic strain lacks the cylE gene, which is necessary for granadaene production31) at a multiplicity of infection (MOI) of 10 for 1 h. This evidence concerns the gene CD4 and infection.