E-cadherin reduces inhibition of HIV-1 replication by virus-specific CD8⁺ T cells. We choose subjects with known strong CD8⁺ T-cell responses to assess the effect of sE-cadherin on their inhibitory capacity. Bulk CD8 T cells directly isolated from peripheral blood by positive selection suppressed R5 replication in autologous CD4 T cells at a 1:1 ratio of CD8 to CD4 T cells. (A) The typical viral growth curve of NL4-3–infected CD4⁺ T cells in all cultures (green). The addition of autologous bulk CD8⁺ T cells lead to robust > 2 log viral inhibition. However, the addition of recombinant E-cadherin to the culture lead to an almost complete abrogation of the inhibitory effect of CD8⁺ T cells and the viral outgrowth being similar to viral outgrowth in absence of CD8⁺ T cells. (B) The effect of viral inhibition of bulk CD8⁺ T cells in the presence or absence of soluble E-cadherin in 5 different elite controllers is summarized. Viral replication was on average 232 072 ± 50 288 p24 pg/mL in the absence of CD8⁺ T cells, but abrogated to on average 42 903 ± 90 868 p24 pg/mL in the presence of bulk CD8⁺ T cells. However, the addition of sE-cadherin diminished the inhibitory effect of CD8⁺ T cells to 106 028 ± 115 919 p24 pg/mL. The strength of this effect was in relation to the expression of KLRG1 on the cell surface of CD8⁺ T cells after the resting period (red numbers). The horizontal line at each variable indicate the mean.