CD4 and infection: As expected, blockade of ICAM-1 with the mAb RM3A5 not only inhibited the formation of mDC-CD4+ T-cell conjugates (Figure 2B), but also impaired the mDC-mediated trans-infection of HIV-1 to CD4+ T lymphocytes by 60% to 70% (p < 0.05, Figure 3B).