A variety of B lymphocyte lineages from human tonsil are susceptible to infection with BAC16 KSHV.

<p>Magnetically sorted total B lymphocytes from four tonsil specimens were infected with KSHV or mock-infected and analyzed by FCM at indicated timepoints for (A) GFP expression and (B) immunophenotypic markers for lineage. In both cases, cells were gated for singlet/viable/CD19+. Memory B cells were further defined as CD38low/IgD-/CD27+, naïve B cells were CD38low/IgD+/CD27-, natural effector (Nat Effector) cells were CD38low/IgD+/CD27+ and germinal center (GC) cells were CD38hi/IgD-. (C) In similar infection experiments with four tonsil specimens, total RNA was extracted at 2, 4 and 6 days post-infection and viral gene transcription was verified in two technical replicates by RT-PCR. Replicate RT negative cDNA reactions for KSHV infected samples at 6 days post-infection were included as a control for DNA contamination and mean NRT Cq values (n = 8) for each target were as follows: 39.44 for LANA, 40.52 for ORF59 and >40 (not detectable) for K8.1. For a 40-cycle reaction, non-amplifying samples were set to Cq = 41 for the purposes of calculation. The lowest Cq value obtained in a mock infected sample was assigned as the limit of detection for each target, and data points that fall below this threshold are denoted with red shading. Yellow shading highlights values between 1.7 and 3.3 cycles lower than the limit of detection and corresponds to 5–10 fold increases in gene expression. Green shading highlights values more than 3.3 cycles lower than the limit of detection and corresponds to gene expression levels greater than 10-fold above the limit of detection. ANOVA analysis of raw Cq values revealed a statistically significant effect of KSHV infection for all target genes when comparing aggregate trends for mock vs KSHV samples over time: LANA p = 0.0006; K8.1 p = 0.02, ORF59 p<0.0001. Student’s T test revealed no significant difference between Cq values for Mock and NRT samples for any target gene. (D) Magnetically sorted naïve B lymphocytes from four tonsil specimens were infected with KSHV or mock-infected and analyzed as in (A) for GFP expression.