FIGURE 6.

Exosomes from infected primary cells contain TAR RNA. A, schematic illustration of elution profiles of exosomes and virions after OptiPrep velocity gradient centrifugation of culture supernatants. MP, molecular weight particles. B, acetylcholinesterase activity of fractions was determined to confirm fraction numbers that contained pure exosomes. The x axis shows the % of iodixanol in the appropriate gradients, and the y axis shows relative AchE function. Error bars show the standard error of two independent preparations. C, total RNA isolated from the fractions of infected primary cell culture supernatants were subjected to qRT-PCR with TAR and env-specific primers. D, total protein obtained from the fractions was subjected to Western blot analysis using antibodies to p24 and quantified. C and D, data are presented as a mean for three independent measurements ± S.D. Single asterisk indicates p ≤ 0.05; double asterisk indicates p ≤ 0.01. SN, supernatant.