Human Adenovirus 11 is a species B adenovirus (subgroup B2) belonging to the genus *Mastadenovirus*. This non‑enveloped virus with a linear double‑stranded DNA genome is known for causing hemorrhagic cystitis and severe respiratory disease in both children and adults.
Structure and Cellular Entry
Adenovirus 11 virions are icosahedral particles composed of hexon and penton base proteins with fiber projections that interact with the complement regulatory protein CD46 on host cells. Engagement of CD46 and integrins facilitates endocytosis and intracellular transport to the nucleus. Early viral genes manipulate host transcription and replication machinery, while the viral DNA polymerase replicates the genome. Late gene products form structural proteins that assemble around replicated genomes to produce new virions. The virus displays tropism for respiratory epithelium and the uroepithelium.
Clinical Significance and Epidemiology
Type 11 adenoviruses are associated with outbreaks of acute respiratory disease, pneumonia, and pharyngitis, particularly in settings such as military barracks and hospitals. They are also a common cause of hemorrhagic cystitis, especially in children and immunocompromised patients, leading to dysuria, hematuria, and bladder discomfort. In renal transplant recipients, adenovirus 11 can cause nephritis and graft dysfunction. Transmission occurs via respiratory droplets, urine, and contaminated surfaces. Laboratory diagnosis is based on PCR or viral culture, and management is mainly supportive; reduction of immunosuppression and antiviral drugs like cidofovir may be considered in severe cases. Because pre‑existing immunity to adenovirus 11 is less prevalent than to type 5, engineered adenovirus 11 vectors are being explored for gene therapy and vaccines. Human adenovirus 11 underscores the diverse tissue tropism of adenoviruses and their capacity to cause both respiratory and urinary tract disease, as well as the potential for vector development. Related Terms: hemorrhagic cystitis, human adenovirus 21, CD46 receptor, respiratory infection, adenoviral vector