Cell-mediated immune response and stability of intraocular transgene expression after adenovirus-mediated delivery.
OBJECTIVE
To evaluate the role of cell-mediated immunity in the stability of ocular adenovirus-mediated transgene expression.


METHODS
Adenovirus (4 x 10(6) pfu) containing lacZ (Ad.CMVlacZ) was injected intravitreally or subretinally into one or both eyes of immunocompetent (+/+) and immunocompromised (nu/nu) CD-1 mice. Control eyes received injections of saline. Additional +/+ mice received subretinal injections of Ad.CMVlacZ with coadministration of 200 microg of human immunoglobulin (Ig) G or CTLA4Ig by intraperitoneal, intravitreal, or subretinal injection. The mice were killed at various times after injection, and their eyes were examined histologically and immunohistochemically.


RESULTS
LacZ expression was extended from 1 week to more than 5 weeks in the corneal endothelium, iris, and trabecular meshwork of nu/nu mice compared with time of expression in +/+ mice when adenovirus was administered intravitreally. In contrast, subretinal injection resulted in only a minimal increase in transgene stability in nu/nu mice compared with that in +/+ mice. Neither systemic nor intraocular administration of IgG or CTLA4Ig affected the stability of lacZ expression in the retina or retinal pigment epithelium after subretinal injection in +/+ mice. Immunoglobulin G and CTLA4Ig enhanced the stability of transgene expression in the trabecular meshwork.


CONCLUSIONS
A T-cell-mediated immune response appears to play a role in the loss of adenovirus-mediated lacZ expression after intravitreal but not after subretinal injection. This result implies that the subretinal space is an immune-privileged site and a favorable site for gene transfer.
Hoffman
L M
LM
Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia 19104-6069, USA.
Maguire
A M
AM
Bennett
J
J
D000069594:Abatacept; D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D000869:Anterior Eye Segment / Q000201:enzymology / Q000821:virology; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000008:administration & dosage; D060908:CTLA-4 Antigen; D003587:Cytomegalovirus / Q000235:genetics; D017931:DNA Primers / Q000737:chemistry; D004797:Enzyme-Linked Immunosorbent Assay; D015870:Gene Expression; D006651:Histocytochemistry; D007111:Immunity, Cellular; D018796:Immunoconjugates; D007124:Immunoenzyme Techniques; D007074:Immunoglobulin G / Q000008:administration & dosage; D007166:Immunosuppressive Agents / Q000008:administration & dosage; D007763:Lac Operon / Q000235:genetics*; D051379:Mice; D008817:Mice, Mutant Strains; D012160:Retina / Q000201:enzymology / Q000821:virology; D013601:T-Lymphocytes / Q000276:immunology*; D019076:Transgenes / Q000235:genetics*; D001616:beta-Galactosidase / Q000378:metabolism
D015703:Antigens, CD; D000943:Antigens, Differentiation; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; C556707:Ctla4 protein, mouse; D017931:DNA Primers; D018796:Immunoconjugates; D007074:Immunoglobulin G; D007166:Immunosuppressive Agents; D000069594:Abatacept; D001616:beta-Galactosidase