Acyclovir

DNA oligonucleotides and guanine derivatives were purchased from Sangon Biotech (Shanghai) Co., Ltd. cGMP was purchased from Sigma-Aldrich. Guanosine and guanine were obtained from Shanghai Standard Technology Co., Ltd. Acyclovir and ganciclovir were obtained from ApexBio Technology. The DNA was dissolved in a buffer containing 37.5 mM KCl, 12.5 mM K₂HPO₄/KH₂PO₄, pH 7, 10/90% D₂O/H₂O. The DNA concentrations were determined using a UV spectrometer. The stock solutions of guanine derivatives were prepared in the same 50 mM K⁺-containing buffer or d₆-DMSO to 75 or 150 mM.

Discarded, de-identified leukocyte fractions left over from platelet
donations were obtained from the Brigham and Women’s Hospital Blood Bank.
Blood cells were collected from platelet donors following institutional
guidelines. Since these were de-identified samples, the gender was unknown. Our
studies on primary human blood cells were approved by the Brigham &
Women’s Hospital Institutional Review Board. Primary human B cells were
isolated by negative selection using RosetteSep Human B Cell Enrichment and
EasySep Human B cell enrichment kits (Stem Cell Technologies), according to the
manufacturers’ protocols. B cell purity was confirmed by plasma membrane
CD19 positivity through FACS. Cells were then cultured with RPMI 1640 with 10%
FCS. Freshly isolated primary B-cells were seeded in complete RPMI media and 10%
FBS at 1 million cells per mL. The following agonists were used at these
concentrations: Mega CD40L (Enzo Life Sciences, Cat#ALX-522–110-C010 50
ng/mL), CpG (Integrated DNA Technologies, CpG ODN 2006, 0.5 μM), goat
anti-human IgM 1 μg/ml (Sigma Cat# I0759) or combinations thereof, as
indicated. Cells were harvested at 24 hours for whole cell lysate preparation.
Acyclovir (APExBio Cat#A8644) was used at 50 ug/ml.