Clone h57 597

Mice were depleted of CD4⁺ and/or CD8⁺ T cell subsets via intraperitoneal administration of anti-CD4 (GK1.5, rat IgG2b) and anti-CD8a (2.43, rat IgG2b) antibodies (Bio X Cell, New Hampshire) (59 (link)). Each mouse received 200 μg per 20 g body weight of GK1.5 and/or 2.43 of control rat IgG2b antibodies in a volume of 200 μL phosphate-buffered saline (PBS) 48 h prior to infection or prior to vaccination depending on the regimen used (see the figures and their legends for details). These mice also received these antibodies weekly thereafter during the observation period. The efficiency of T cell depletion was monitored by flow cytometry on peripheral blood samples. Briefly, red blood cells (RBC) were lysed by treatment with Ammonium-Chloride-Potassium (ACK) lysing solution, and cells were washed with PBS. Cells were stained with a mixture of anti-mouse immunoglobulin antibodies, including Fc block (unlabeled anti-CD16/32; clone 93; Invitrogen), anti-T cell receptor β (TCRβ) (fluorescein isothiocyanate [FITC]; clone H57-597; eBioscience), anti-CD4 (allophycocyanin [APC]; clone RM4-5; eBioscience), and anti-CD8α (efluor 450; clone 53-6.7; eBioscience) for 10 min at 4°C in the dark. Cells were washed with cold PBS and immediately analyzed on a Novocyte Quanteon flow cytometer. The percentage of TCRβ⁺ T cells expressing either CD4 or CD8 was calculated.