Dataset Information

Characterization of the ocular inflammatory response to AAV reveals divergence by sex and age

ABSTRACT: Recombinant adeno-associated virus (AAV) is the leading platform for gene therapy in ocular disease. Progress for gene therapy has been hindered by AAV-induced inflammation, which limits dose escalation and long-term efficacy. Characterisation of the ocular immune response to AAV in mice has been restricted to young animals and demonstrate activation of microglia, antigen presentation and a dominant T cell lymphocyte infiltration. The extent of the inflammatory response alters with age and sex and these factors have not been fully represented in the pre-clinical development of ocular AAV gene therapies. Here, we intravitreally inject a null AAV2 vector in young (3-month), middle aged (9-month) and old (18-month) Cx3cr1-creER:R26tdTomato+/- mice of both sexes. Applying clinical imaging, flow cytometric analyses and bulk-sequencing of sorted resident microglia we interrogate the impact of sex and age on the longitudinal response of both microglia and infiltrating cellular response to AAV. Young animals have a dynamic response, with a peak in inflammation at D10-12 and signs of clinical resolution by D28. Despite similar kinetics in the inflammatory response between young male and females, sex differences are observed in the magnitude of the transcriptional response by microglia and the adaptive component of the infiltrating response. With age, the inflammation increases and persists after AAV2 injection. Based on the microglia transcriptional response to AAV, males maintain similar signature across age, although enhanced with increasing age. Contrary, females have greater divergence in their inflammatory response across age. Of particular note, old females have enriched cellular stress and inflammatory microglia gene signatures, with corresponding retinal degeneration. These findings inform crucial sex and age differences for therapeutic application of ocular gene therapy. Our dataset highlight the need to further define these differences to appropriately tackle AAV immunogenicity for all populations.

ORGANISM(S): Mus musculus

PROVIDER: GSE266332 | GEO | 2025/01/29

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Microglia, the brain’s principal immune cells, have been implicated in the pathogenesis of Alzheimer’s disease (AD), a condition shown to affect more females than males. Although sex differences in microglial function and transcriptomic programming have been described across development and in disease models of AD, no studies have comprehensively identified the sex divergences that emerge in the aging mouse hippocampus. Further, existing models of AD generally develop pathology (amyloid plaques and tau tangles) early in life and fail to recapitulate the aged brain environment associated with late-onset AD. Here, we examined and compared the transcriptomic and translatomic sex effects in young and old murine hippocampal microglia. Hippocampal tissue from C57BL6/N and microglial NuTRAP mice of both sexes were collected at young (5-6 month-old [mo]) and old (22-25 mo) ages. Cell sorting and affinity purification techniques were used to isolate the microglial transcriptome and translatome for RNA-sequencing and differential expression analyses. Flow cytometry, qPCR, and imaging approaches were used to confirm the transcriptomic findings. There were marginal sex differences identified in the young hippocampal microglia, with most differentially expressed genes (DEGs) restricted to the sex chromosomes. Both sex chromosomally- and autosomally-encoded sex differences emerged with aging. These sex DEGs identified at old age were primarily female-biased and enriched in senescent and disease-associated microglial signatures. Pathway analyses identified upstream regulators induced to a greater extent in females than in males, including inflammatory mediators IFNG, TNF, and IL1B, as well as AD-risk genes TREM2 and APP. These data suggest that female microglia adopt disease-associated and senescent phenotypes in the aging mouse hippocampus, even in the absence of disease pathology, to a greater extent than males. This sexually divergent microglial phenotype may explain the difference in susceptibility and disease progression in the case of AD pathology. Future studies will need to explore sex differences in microglial heterogeneity in response to AD pathology and determine how sex-specific regulators (i.e., sex chromosomal or hormonal) elicit these sex effects.

Dataset Information

Characterization of the ocular inflammatory response to AAV reveals divergence by sex and age

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets