Human cytomegalovirus (HCMV) infection can cause inflammatory tissue-invasive end-organ diseases upon lytic replication. In humans, mature miR-200b-3p and -200c-3p suppress the synthesis of HCMV immediate early 2 (IE2) protein by binding to the 3′-UTR of the mRNA encoded by the unique long (UL) 122-123 region in human foreskin fibroblasts and pre-transplant peripheral blood mononuclear cells stimulated with HCMV. The present study aimed to quantitate the expression of Homo sapiens (hsa)-miR-200b-3p and 200c-3p in HCMV-infected tissues. We collected 240 HCMV-infected and 154 HCMV-non-infected, formalin-fixed, paraffin-embedded tissue samples of the gastrointestinal (GI) tract and bronchi/lungs. MiRNAs, HCMV, and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were quantitated by quantitative reverse transcription-PCR (qRT-PCR) and quantitative PCR (qPCR) on the basis of standard curves generated using miRNA mimics, the HCMV strain from National Institute for Biological Standards and Control (NIBSC) 09/162, and GAPDH control. To avoid the effect of cell counts on the qRT-PCR and qPCR results, the data were normalized to GAPDH levels. HCMV-infected tissues had significantly lower levels of 200b-3p/GAPDH (3.03 ± 1.50 compared with 3.98 ± 1.08 log10 copies/μl, P<0.001) and 200c-3p/GAPDH (4.67 ± 1.84 compared with 6.35 ± 1.47 log10 copies/μl, P<0.001) than normal tissues. The values for 200b-3p/GAPDH (r = −0.51, P<0.001) and 200c-3p/GAPDH (r = −0.54, P<0.001) were significantly inversely correlated with HCMV load. Low tissue levels of 200b-3p and 200c-3p in humans are associated with cytopathic inflammation due to HCMV infection.

Background Letermovir, an inhibitor of unique long (UL)56-encoded cytomegalovirus (CMV)-terminase, shows prophylactic effects with low-grade adverse events in hematopoietic stem cell transplant recipients. Despite few case reports on acquired letermovir resistance, the frequency of de novo amino acid (A.A.) changes encoded by UL56 in CMV-infected tissues is unclear. Methods We analyzed CMV UL56 sequences between the conserved region IV and variable region I in 175 formalin-fixed, paraffin-embedded tissues obtained from 147 patients showing positive CMV immunochemical staining between November 2012 and October 2016. Nucleotides 552–1330 of the open reading frame of UL56 were amplified with 5 primers and sequenced by a dideoxy fluorescence-based cycle. Results Six (3.4%) tissues from 4 (2.7%) patients harbored A.A. substitutions. There were no known potent resistant mutations. However, we found C325Y in 2 tissues from 1 patient, along with other mutations. Four novel A.A. changes, which have not been observed in previous in vitro experiments, were identified (T244I, S301T, G312V, and M434I). Most (9 of 11, 81.8%) of the A.A. changes occurred between the codons 301 and 325 present between the conserved regions V and VI. Conclusions The treatment difficulties associated with letermovir resistance in a clinical setting need to be verified before its widespread use.

Pemphigus is an autoimmune mucocutaneous blistering disease caused by autoantibodies against desmogleins. Rituximab effectively treats pemphigus by inducing remission and rapidly reducing corticosteroid dosage. In Korea, the high cost of rituximab had been a burden until the National Health Insurance began to cover 90% of rituximab costs via reimbursement for severe pemphigus patients. We analyzed 214 patients with pemphigus who were treated with their first round of rituximab. The time to initiate rituximab and the time to partial remission under minimal therapy (PRMT) were both significantly shorter after the rituximab reimbursement policy. The total steroid intake for PRMT and complete remission (CR) was less in patients who were diagnosed after the reimbursement. The interrupted time series (ITS) model, a novel analysis method to evaluate the effects of an intervention, showed a decrease in total systemic corticosteroid intake until PRMT after reimbursement began. In peripheral blood mononuclear cells from patients with pemphigus vulgaris, the relative frequencies of desmoglein 3-specific CD11c+CD27−IgD− atypical memory B cells positively correlated with the periods from disease onset to rituximab treatment and to PRMT and the total systemic corticosteroid intake until PRMT. We found that early rituximab therapy, induced by the reimbursement policy, shortened the disease course and reduced the total corticosteroid use by pemphigus patients. The decreased frequency of circulating desmoglein-specific atypical memory B cells can be used as a surrogate marker for a good prognosis after rituximab.

Attenuating the expression of immediate early (IE) proteins is essential for controlling the lytic replication of human cytomegalovirus (HCMV). The human microRNAs (hsa-miRs), miR-200b-3p and miR-200c-3p, have been identified to bind the 3′-untranslated region (3′-UTR) of the mRNA encoding IE proteins. However, whether hsa-miRs can reduce IE72 expression and HCMV viral load or exhibit a crosstalk with the host cellular signaling machinery, most importantly the NF-κB cascade, has not been evaluated. In this study, argonaute-crosslinking and immunoprecipitation-seq revealed that miR-200b-3p and miR-200c-3p bind the 3′-UTR of UL123, which is a gene that encodes IE72. The binding of these miRNAs to the 3′-UTR of UL123 was verified in transfected cells stably expressing GFP. We used miR-200b-3p/miR-200c-3p mimics to counteract the downregulation of these miRNA after acute HCMV infection. This resulted in reduced IE72/IE86 expression and HCMV VL during lytic infection. We determined that IE72/IE86 alone can inhibit the phosphorylation of RelA/p65 at the Ser536 residue and that p-Ser536 RelA/p65 binds to the major IE promoter/enhancer (MIEP). The upregulation of miR-200b-3p and miR-200c-3p resulted in the phosphorylation of RelA/p65 at Ser536 through the downregulation of IE, and the binding of the resultant p-Ser536 RelA/p65 to MIEP resulted in a decreased production of pro-inflammatory cytokines. Overall, miR-200b-3p and miR-200c-3p—together with p-Ser536 RelA/p65—can prevent lytic HCMV replication during acute and latent infection.