Related Experiment Videos
Cytomegalovirus infection of human retinal tissue: an in vivo model
D DiLoreto1, L G Epstein, E S Lazar
1Department of Neurobiology and Anatomy, University of Rochester School of Medicine, New York.
Background:
Cytomegalovirus (CMV) retinitis is a common, devastating complication of AIDS. Strict host specificity of human CMV (HCMV), has limited the study of the virus. The purpose of this research was to create a model that allowed the in vivo infection of human retinal tissue with HCMV.
Experimental Design:
Small fragments of 13-week human fetal retina were transplanted into the anterior chambers of immune-deficient mice. One week later, 15 of 30 grafts were inoculated with HCMV. Infected and noninfected specimens were compared for histopathologic changes at 14, 30, and 60 days at light and electron microscopic levels. Histochemistry was performed to characterize: level of graft differentiation, range of viral replication cycle, and effects on neuronal, glial, and monocytic elements of the retina.
Results:
At 30 and 60 days, grafts were well differentiated histologically and histochemically. The infected grafts showed numerous large cells containing intranuclear and intracytoplasmic inclusions. Ultrastructural examination revealed viral particles within cytoplasm and nuclei. Infected cells expressed proteins representative of all phases of the HCMV replication cycle. Most HCMV-infected cells expressed the neuronal marker, protein gene product 9.5. In a second series of experiments, tissue from one graft harvested at 45 days postinfection was used to recover HCMV in fibroblast cultures and also used successfully to passage the virus to two control grafts.
Conclusions:
This model allows HCMV to actively infect and replicate within highly differentiated human neural tissue. It produces pathology characteristic of CMV-infected neural tissue in a time course suitable for long-term study. The nature of this model will allow the study of: the replication properties of HCMV in nervous tissue, the specific effects of HCMV on the human retina, the interaction of HCMV with other viruses, e.g., HIV, and various anti-viral therapies.
Insights
Researchers developed a novel model to study human cytomegalovirus (CMV) infection in human retinal tissue. This model allows for in vivo investigation of CMV retinitis, a major complication in AIDS patients.
Area of Science:
- Ophthalmology
- Virology
- Immunology
Background:
- Cytomegalovirus (CMV) retinitis is a severe complication of Acquired Immunodeficiency Syndrome (AIDS).
- The host specificity of human CMV (HCMV) has historically limited research into its effects on human tissues.
- A need existed for a model to study HCMV infection in human retinal tissue in vivo.
Purpose of the Study:
- To establish a model for in vivo infection of human retinal tissue with human cytomegalovirus (HCMV).
- To investigate the pathological effects of HCMV on differentiated human neural tissue.
Main Methods:
- Human fetal retinal tissue fragments were xenotransplanted into immune-deficient mice.
- Grafts were inoculated with HCMV, and infected and non-infected tissues were analyzed histologically and ultrastructurally.
- Histochemistry was used to assess graft differentiation, viral replication, and cellular effects.
Main Results:
- HCMV successfully infected and replicated within differentiated human retinal grafts.
- Infected cells exhibited characteristic viral inclusions and particles, expressing all phases of the HCMV replication cycle.
- Infected cells predominantly expressed the neuronal marker, protein gene product 9.5, and the virus was successfully passaged to new grafts.
Conclusions:
- A viable model was created for studying HCMV infection in human neural tissue.
- This model facilitates long-term investigation of HCMV replication, retinal pathology, and interactions with other viruses like HIV.
- The model supports research into potential anti-viral therapies for HCMV-related conditions.