Role of cytomegalovirus on the maturation and function of monocyte derived dendritic cells of liver transplant patients

Transcriptomic analysis of human cytomegalovirus to survey the indirect effects on renal transplant recipients

Post-transplant human cytomegalovirus (HCMV) viremia has been linked to adverse "indirect effects" among transplant patients. HCMV-created immunomodulatory mechanisms could be associated with the indirect effects.

OBJECTIVE

In the present study, the RNA-Seq whole transcriptome of renal transplant (RT) patients was analyzed to seek the underlying pathobiologic pathways associated with the long-term indirect effects of HCMV.

METHODS

To investigate the activated biological pathways in HCMV infection, total RNA was extracted from PBMCs of 2 RT patients with active HCMV and 2 RT patients without infection and then were sequenced using RNA-Seq. The resulted raw data were analyzed by conventional RNA-Seq software to determine the Differentially Expressed Genes (DEGs). Afterward, Gene Ontology (GO) and pathway enrichment analyses were conducted to determine the enriched pathways and biological processes by DEGs. Eventually, the relative expressions of some significant genes were validated in the twenty external RT patients.

RESULT

The analysis of RNA-Seq data related to RT patients with HCMV active viremia led to the identification of 140 up-regulated and 100 down-regulated DEGs. KEGG pathway analysis revealed the enrichment of DEGs in IL18 signaling, AGE-RAGE signaling pathway in diabetic complications, signaling by GPCR, Platelet activation, signaling and aggregation, Estrogen signaling pathway and signaling by Wnt due to HCMV infection. The expression levels of six genes involved in enriched pathways including F3, PTX3, ADRA2B, GNG11, GP9, HBEGF were then verified using RT-qPCR. The results were in consistent with RNA-Seq resultsoutcomes.

CONCLUSION

This study specifies some pathobiological pathways which are activated in HCMV active infection and could be linked to the adverse indirect effects caused by HCMV infection in transplant patients.

Post-Liver Transplant Cytomegalovirus (CMV) Reactivation, Graft, and Patient Survival Rates in Iranian Population

Background: Human cytomegalovirus (CMV) is the major complication of viral infection in immunocompromised patients. This opportunistic infection is associated with high morbidity and mortality in transplanted recipients. Objectives: The present study aimed to determine CMV burden and assess the clinical outcome in the liver recipients with CMV reactivated infection at Nemazi Hospital, Shiraz, Iran. Methods: This retrospective study examined 657 patients who underwent liver transplantation during 2014 - 2017 to identify the CMV infection, morbidity, and mortality rates. To this end, the medical records of such patients were reviewed, and their rejection/survival rates were analyzed. Accordingly, the CMV infection was diagnosed by Taq-Man real-time PCR assays. Results: In this study, 151 (23%) had CMV reactivation at least one year after liver transplantation. Viremic patients had a viral burden between 300 - 738790 copies/mL. In this study, 41 persons (6.2%) died, and 58 liver transplant patients (8.8%) had rejection experience up to one year after their operation. Among the 41 dead patients, 21 and 20 cases were with and without CMV-reactivation, respectively. The results demonstrated that the mortality rate was significantly higher in the CMV-infected patients than the non-CMV-infected counterparts. In contrast, the graft survival rate was not significantly different between the two groups (P ≤ 0.05). Conclusions: In the present study, CMV infection can serve as a significant mortality predictor in LT patients.

Toll-Like 4 Receptor Expression on Peripheral Blood Mononuclear Cells in Renal Transplant Recipients Can Help to Indicate the Risk of Graft Deterioration in Patients Who Experienced an Episode of Symptomatic Cytomegalovirus Infection

Data binding the expression of Toll-like 4 receptor (TLR4), transplanted kidney (KT) function, and symptomatic CMV infection (CMV+) are scarcely available.

OBJECTIVE

To investigate the relationship between TLR4 expression (TLR4ex) in patients who had a relapse of CMV and transplant function.

MATERIALS AND METHODS

TLR4ex was measured in peripheral blood mononuclear cells of KT recipients. We compared TLR4ex among 30 CMV+ patients and 87 patients without CMV infection (CMVneg). At the beginning (day 0) TLR4ex, as well as concentrations of cyclosporin A and tacrolimus were determined. All patients, CMV+ and CMVneg patients were divided according to the respective median of TLR4ex into groups of low-TLR4 expression (L-TLR4ex) and high-TLR4 expression (H-TLR4ex). Estimated glomerular filtration rate (EGFR) was assessed on day 0 and after the follow-up (F-up). The magnitudes of EGFR change (ΔEGFR) were evaluated. Stable treatment along the F-up period (median 11.9 months) was applied.

RESULTS

TLR4ex of CMV+ in 67% was below median for all patients. For day 0, in CMV+: no link of TLR4ex with EGFR was found; TLR4ex was lower but day 0 EGFR did not differ from H-TLR4ex. In CMVneg, a GFR-TLR4ex link was present. Post F-up. In CMV+ with L-TLR4ex, EGFR declined, with no change in H-TLR4ex. In CMVneg with H-TLR4ex, EGFR increased, with no change in L-TLR4ex. Both regression and receiver operating characteristic curve analyses points out the impact of CMV+ and TLR4ex on eGFR and ΔEGFR.

CONCLUSION

In CMV+, low TLR4ex increases the risk of EGFR deterioration. In CMVneg, high TLR4ex raises the chance of EGFR improvement.

Association between Interleukin-21, 23 and 27 Expression and Protein Level with Cytomegalovirus Infection in Liver Transplant Recipients

BACKGROUND

Cytokines have regulatory crosstalk with CMV infection leading to manage of post-liver transplantation virus-related outcomes.

OBJECTIVE

To investigate the link between IL-21, IL-23 and IL-27 mRNA and protein level with active CMV infection, which was evaluated in reactivated and non-reactivated liver transplant recipients.

METHODS

Two groups of liver transplant recipients were enrolled in this study-54 without and 15 with active CMV infection. 3 EDTA-treated blood samples were taken on day 1, 4, and 7 post-liver transplantation. Plasma and buffy coats of all samples were separated. All samples were analyzed for CMV reactivation using antigenemia technique. The separated plasma of positive samples was used for viral DNA extraction and protein evaluation. For evaluating the mRNA expression level by real-time PCR, RNA extraction and cDNA synthesis were done for all samples. Also, the protein level of studied genes was estimated by ELISA.

RESULTS

The expression level of IL-21, IL-23A and IL-27A cytokine genes was increased in CMV reactivated liver transplant recipients in comparison with CMV non-reactivated ones; IL-27A expression pattern was significant (p=0.001) at all sampling times. IL-21 significantly increased on the 2^nd and 3^rd (p=0.028 and 0.01, respectively) sampling days in CMV reactivated compared with non-reactivated patients. The expression level of IL-23A cytokine significantly increased on the 3^rd (p=0.017) sampling day in CMV reactivated compared with non-reactivated liver transplant recipients.

CONCLUSION

Elevation in the expression level of IL-21, IL-23A and IL-27A mRNA and protein level in CMV reactivated patients emphasized on the antiviral role of these cytokines in CMV reactivated liver transplant recipients.

Cytomegalovirus Infection Exacerbates Experimental Colitis by Promoting IL-23 Production

Many studies have demonstrated an association between cytomegalovirus (CMV) infection and inflammatory bowel disease (IBD). Moreover, CMV infection is more common in patients with severe or steroid-refractory IBD. However, it is not clarified whether CMV worsens IBD or if it is merely a surrogate marker for IBD. Here, we used the dextran sodium sulfate (DSS)-induced colitis model to investigate if CMV infection exacerbates colitis. The mice were injected intraperitoneally with 10 MOI of murine CMV (MCMV) and thereafter, chronic colitis was induced by one cycle of DSS exposure. Anti-IL-23R mAb at 20 μg/mice and pyrrolidine dithiocarbamate (PDTC), an effective NF-κB inhibitor, at 50 mg/kg were administrated to the mice. The MCMV-infected mice had a shorter colon length and a higher histopathology score than the mock inoculum-treated mice, while anti-IL-23R mAb administration ameliorated the pathological changes. Expression of IL-23, phospho-NF-κB p65, and phospho-IκBα was upregulated in colon tissues of the MCMV-infected mice compared to mock inoculum-treated mice, while treatment with PDTC attenuated colonic IL-23 production. These data demonstrated that CMV infection could accelerate IBD development. This effect may be due to its activation on NF-κB signaling pathway and subsequently IL-23 production.