Targeting IL-11 in the treatment of BK virus-associated haemorrhagic cystitis-A promising new approach

Engagement of AKT and ERK signaling pathways facilitates infection of human neuronal cells with West Nile virus

West Nile virus (WNV) is an important neurotropic virus that accounts for the emergence of human arboviral encephalitis and meningitis. The interaction of WNV with signaling pathways plays a key role in controlling WNV infection. We have investigated the roles of the AKT and ERK pathways in supporting WNV propagation and modulating the inflammatory response following WNV infection. WNV established a productive infection in neuronal cell lines originated from human and mouse. Expression of IL-11 and TNF-α was markedly up-regulated in the infected human neuronal cells, indicating elicitation of inflammation response upon WNV infection. WNV incubation rapidly activated signaling cascades of AKT (AKT-S6-4E-BP1) and ERK (MEK-ERK-p90RSK) pathways. Treatment with AKT inhibitor MK-2206 or MEK inhibitor U0126 abrogated WNV-induced AKT or ERK activation. Strong activation of AKT and ERK signaling pathways could be detectable at 24 h after WNV infection, while such activation was abolished at 48 h post infection. U0126 treatment or knockdown of ERK expression significantly increased WNV RNA levels and viral titers and efficiently decreased IL-11 production induced by WNV, suggesting the involvement of ERK pathway in WNV propagation and IL-11 induction. MK-2206 treatment enhanced WNV RNA replication accompanied with a moderate decrease in IL-11 production. These results demonstrate that engagement of AKT and ERK signaling pathways facilitates viral infection and may be implicated in WNV pathogenesis.

The effect of the BK polyomavirus large T antigen on the function and maturity of the CD4+ T cell subsets in kidney transplant recipients

BACKGROUND

In kidney transplant recipients (KTRs) who are immunosuppressed, human BK polyomavirus (BKPyV) infection can be reactivated, resulting in BKPyV-associated nephropathy (BKPyVN). Considering that BKPyV inhibits CD4+ T cell differentiation, we investigated the effect of BKPyV large T antigen (LT-Ag) on the maturation of CD4+ T cell subsets during active BKPyV infection.

METHODS

In this cross-sectional study, we examined the following groups: 1) five KTRs with active viral infection (BKPyV+ KTRs), 2) five KTRs without active viral infection (BKPyV-KTRs), and 3) five healthy controls. We measured the frequency of CD4+ T cells and their different subsets, such as naive T cells, central memory T cells (Tcm), and effector memory T cells (Tem). All these subsets were analyzed by flow cytometry in peripheral blood mononuclear cells (PBMCs) stimulated with the overlapping BKPyV LT-Ag peptide pool. In addition, CD4+ T cell subsets were analyzed by flow cytometry for the presence of CD4, CCR7, CD45RO, CD107a, and granzyme B (GB). In addition, mRNA expression of transcription factors (TFs) such as T-bet, GATA-3, STAT-3, and STAT-6 was examined. The probability of inflammation with perforin protein was examined by SYBR Green real-time PCR.

RESULTS

After stimulation of PBMCs, naive T cells (CD4+CCR7+CD45RO-) (p = 0.9) and CD4+ T cells which release CD107a+ (CD4+CD107a+Geranzyme B-) (p = 0.9) T cells were more abundant in BKPyV+ KTRs than in BKPyV- KTRs. In contrast, central memory T cells (CD4+CCR7+CD45RO+) (p = 0.1) and effector memory T cells (CD4+CCR7-CD45RO+) (p = 0.1) were more abundant in BKPyV- KTRs than in BKPyV+ KTRs. The mRNA expression levels of T-bet, GATA-3, STAT-3, and STAT-6 were significantly higher (p < 0.05) in BKPyV- KTRs than in BKPyV+ KTRs which may be due to a higher differentiation level of CD4+ T cells. Due to inflammation, the mRNA expression level of perforin was higher in BKPyV+ KTRs, than in BKPyV- KTRs, but the difference was not significant (p = 0.175).

CONCLUSIONS

The high number of naive T cells after PBMC stimulation with the LT-Ag peptide pool was observed in BKPyV+ KTRs due to the interaction of LT-Ag with T cells. This means that BKPyV by using its LT-Ag can inhibit the naive T cell differentiation to other T cell subsets like central and effector memory T cells. However, the frequency of CD4+ T cell subsets and the combination of the activities of these cells with the expression profile of the target genes in this study may be efficient in treating and diagnosing BKPyV infections in kidney recipients.

Urinary Tract Infections: Virus

Although viruses are common in the urinary tract in healthy people, viral infections can become a major concern in immunocompromised individuals. Patients undergoing hematopoietic stem cell or solid organ transplantation may be particularly susceptible to BK and other viruses, and experience a high risk of mortality. The most common presentation in this setting is hemorrhagic cystitis. The treatment is mostly supportive, including the reduction of immunosuppression; a variety of experimental agents has also been proposed. A different context is offered by chronic (HBV, HCV, HIV) or acute/subacute (Dengue, Hantavirus, etc.) infections, where the kidneys can be secondarily involved and suffer from several glomerular syndromes. Many protocols based on different oral direct-acting antivirals and combined antiretrovirals are available, according to the systemic infection. Viral infections can be classified according to the organ involved, i.e. lower (bladder) or upper urinary tract (kidneys, ureters), and to the mechanism of injury. A section is dedicated to the current breakout of SARS-CoV-2, which does not spare the urinary tract, sometimes with serious implications. Even if this topic is mostly the discipline of ultra-dedicated physicians, this overview has a practical approach and could be useful to a wider medical audience, especially in times of viral pandemics.

[Viral infections in urology]

Einleitung

Die COVID-19-Pandemie („coronavirus disease 2019“) hat eindrucksvoll gezeigt, dass Infektionskrankheiten enorme Auswirkungen auf das Gesundheitswesen und darüber hinaus haben können. In der Urologie spielen Viren bei spezifischen Entitäten eine Rolle, wo sich der Urologe mit Viruserkrankungen beschäftigen muss.

Methodik

Diese Übersichtsarbeit hat zum Ziel in der Urologie relevante Virusinfektionen zu beschreiben und insbesondere die Impfprävention hervorzuheben. Es erfolgte eine selektive Literaturrecherche zu den Themen „COVID und Urologie“, „Urogenitale Virusinfektionen“, „Virale urologische Infektionen in der Transplantationsmedizin“ sowie „Impfprävention von Viruserkrankungen“.

Ergebnisse

Coronaviren sind Viren, die bereits 2‑mal lokale Epidemien verursacht haben (SARS- [„severe acute respiratory syndrome“] und MERS-Epidemie [„middle east respiratory syndrome“]). Die Tatsache, dass die SARS-CoV-2-Erkrankung („severe acute respiratory syndrome coronavirus 2“) auch ohne Symptome ansteckend ist, hat im Wesentlichen zu der raschen Ausbreitung und weltweiten Pandemie geführt. Eine Vielzahl von Viren, die auch eine Virämie induzieren können, wurde im Ejakulat nachgewiesen und wird damit mit einer etwaigen urogenitalen Infektion in Verbindung gebracht. Hierzu zählen u. a. das Mumps‑, Coxsackie-Viren oder Enteroviren. Es wurde auch gezeigt, dass auch eine Zika-Virusinfektion sexuell über die Spermien als Carrier übertragen werden kann. Somit spielen Viren auch eine wichtige Rolle in der Reproduktion. Bei der Nierentransplantation sind Urologen häufig mit viralen Infektionen konfrontiert. Die effektivste Waffe gegenüber Viren stellt die Impfprävention dar.

Schlussfolgerung

Äthiopathogenetisch ist der Urogenitaltrakt im Rahmen einer Virämie oder über eine Reaktivierung durch eine Immunsuppression am häufigsten mitbetroffen. Therapeutisch kommt der Immunmodulation sowie der Impfprophylaxe eine führende Rolle zu.

Significance of BK Polyomavirus in Long-Term Survivors after Adult Allogeneic Stem Cell Transplantation

Simple Summary

Allogeneic stem cell transplantation is a curative treatment option for several hematological diseases. Data about health status and late complications of long-term survivors of this therapy are limited, so we conducted a prospective study. This analysis focusses on kidney function and urological complications. Interestingly, the BK polyomavirus plays an important role in this patient population and can lead to severe impairment of kidney function. This was only previously described in the acute situation following transplantation. Further studies should address causal therapy development for this severe viral infection.

Abstract

Background: Allogeneic stem cell transplantation (aSCT) is a common treatment for a variety of hematological diseases. Advances in transplantation practices have led to an increasing number of long-term aSCT survivors, but data about health status and late complications are sparse. This analysis focusses on kidney function and urological complications in this population. Methods: This study is a prospective unicentric non-interventional trial. Before starting the study, we obtained the approval of the local ethics review board. Furthermore, the study was registered at WHO Clinical Trial Registry. The study protocol is available via UTN. Results: We were able to include 33 patients with a mean age of 60.5 years (SD 11.1). The median survival time following allogeneic stem cell transplantation was 9.0 years (IQR 8.5–13.0). Five patients (15.2%) had BKPyV viruria with mean 218.3 (SD 674.2) copies/mL. BKPyV viruria was significantly linked to pre-existing chronic kidney failure (p = 0.019), creatine > 100 µmol/L (p < 0.001), and cystatin c > 1.11 mg/L (p = 0.021), respectively. We were not able to identify a single risk factor for BKPyV viruria in univariate or multivariate Cox regression. Conclusions: BKPyV-associated nephropathy might be one reason for impaired kidney function in long-term survivors of aSCT.

Management of BK virus-associated haemorrhagic cystitis in allogeneic stem cell transplant recipients

BK virus (BKV)-related haemorrhagic cystitis (HC) is an important cause of morbidity following allogeneic haematopoietic stem cell transplantation (HSCT). The various risk factors include high-level BKV viruria and/or viremia, myeloablative conditioning, acute graft versus host disease (GVHD), cytomegalovirus viremia, and unrelated or HLA-mismatched donor. The presence of high plasma BK viral load and cytopenias have been implicated as important predictors for protracted disease course. These patients frequently require hospitalisation which may extend for several weeks. Supportive measures in the form of analgesics, intravenous hydration, bladder irrigation, and transfusion support remain the mainstay of management. Various drugs have been used with limited success in this setting. These include antiviral drugs, fluoroquinolones, leflunomide, growth factors, clotting factors, estrogens, and prostaglandins. The role of adoptive cellular immunotherapy has also been explored but lacks clinical validation. The strategies aimed at expediting urothelial repair like hyperbaric oxygen therapy (HBOT), intravesical fibrin glue and platelet-rich plasma (PRP) are emerging. Some patients with severe disease do require surgical intervention to relieve urinary obstruction. The frequent co-occurrence of acute GVHD and CMV disease further complicates the management in such patients. There is an unmet need for effective and evidence-based options for the prevention and management of this disease. Due to lack of robust data supported by randomised trials, the acceptability of the available guidelines to simplify the treatment is expected to be low. Despite the availability of various treatment options, the management of BKV-related HC in day-to-day practice continues to be a challenge. The aim of this article is to put forward an up-to-date review of the preventive and therapeutic strategies for BKV-related HC.

Targeting IL-11 in the treatment of BK virus-associated haemorrhagic cystitis-A promising new approach

The BK polyomavirus (BKPyV) has pathogenic relevance especially in immunocompromised patients. No causal therapy has been established yet. Therefore, new therapeutic targets need to be identified in experimental studies. A 3D organotypic cell culture model with primary urothelial cells and fibroblasts was used as infection model. The detection of virus replication was performed with quantitative polymerase chain reaction (qPCR), and immunohistochemistry (IHC) was also used for analysis. Interleukin levels were measured by enzyme‐linked immunosorbent assay (ELISA). Interestingly, the signal transducer and activator of transcription 3 (STAT3) pathway seems to be activated during infection with BKPyV, for example phosphorylated STAT3 is significantly (P < 0.0001) elevated on day 6 following infection. Therefore, we performed ELISAs for involved interleukins in STAT3 pathway. Interleukin 11 (IL‐11) was significantly (P = 0.026) elevated at day 9. Subsequently, 3D cultures were treated with IL‐11 neutralizing antibody. At day 9 following infection, the median virus replication rate is 4.4 × 10⁶ copies/ml. The difference to replication rate without treatment was significantly lower at day 6 (P < 0.0001) and at day 9 (P < 0.0001), respectively. STAT3 pathways seem to be involved during BKPyV infection and need further investigation in experimental studies. A very promising target for treatment might be IL‐11.