Expansion of T lymphocytes with the superagonistic CD28 antibody D665.

<p>(<b>A</b>) Two week old uninfected C57BL/6 mice were i.p. injected with 100 µg mAb D665 or PBS (control) and analyzed 3 days later. Lymphocytes were isolated from the spleen and lymph nodes (12 per mouse; 6 cervical, 4 axillary and 2 inguinal lymph nodes). FACS dot plot examples for CD4⁺ Foxp3⁺ T cells in the lymph nodes are shown (left panels: ctrl and +mAb D665 with percentages of all gated lymphocytes). Right panel: quantitative evaluation of the proportion of Foxp3⁺ T cells (percent of all CD4⁺ T cells) in spleen and lymph nodes of D665-treated and control animals (mean values ± SEM, n = 4, P<0.01). (<b>B</b>) Experimental setup used for the treatment of MV-infected mice with mAb D665. As a control an appropriate volume of PBS was injected. (<b>C</b>) The total number of lymphocytes in the spleen and draining lymph nodes (LN) (n = 3; P<0.01), and total number of percoll-isolated cells in brains of D665-treated and control animals (n = 3). (<b>D</b>) Quantitative evaluation of CD4⁺ Foxp3⁺ Tregs in the spleen and LN of D665-treated and control animals (percent CD4⁺Foxp3⁺ cells of all CD4⁺ T cells; n = 3, P<0.002 and P<0.02, respectively).