Also among women with genital tractChlamydia infection, peripheral CD3+CD4+ and CD3+ CD4- cells thatproliferated in response to ex vivo stimulation withinactivated chlamydial antigen secreted significantly more interleukin (IL)-4than tumor necrosis factor, interferon-γ, or IL-17; findings that repeatedin T cells isolated from these same women 1 and 4 months after infection hadbeen eradicated. Here, CD4 is linked to infection.