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Cerebral (Aβ) plaque and (pTau) tangle deposition are hallmarks of Alzheimer's disease (AD), yet are insufficient to confer complete AD-like neurodegeneration experimentally. Factors acting upstream of Aβ/pTau in AD remain unknown, but their identification could enable earlier diagnosis and more effective treatments. T cell abnormalities are emerging AD hallmarks, and CD8 T cells were recently found to mediate neurodegeneration downstream of tangle deposition in hereditary neurodegeneration models. The precise impact of T cells downstream of Aβ/pTau, however, appears to vary depending on the animal model. Our prior work suggested that antigen-specific memory CD8 T (" hi T") cells act upstream of Aβ/pTau after brain injury. Here, we examine whether hi T cells influence sporadic AD-like pathophysiology upstream of Aβ/pTau. Examining neuropathology, gene expression, and behavior in our hi T mouse model we show that CD8 T cells induce plaque and tangle-like deposition, modulate AD-related genes, and ultimately result in progressive neurodegeneration with both gross and fine features of sporadic human AD. T cells required Perforin to initiate this pathophysiology, and IFNγ for most gene expression changes and progression to more widespread neurodegenerative disease. Analogous antigen-specific memory CD8 T cells were significantly elevated in the brains of human AD patients, and their loss from blood corresponded to sporadic AD and related cognitive decline better than plasma pTau-217, a promising AD biomarker candidate. We identify an age-related factor acting upstream of Aβ/pTau to initiate AD-like pathophysiology, the mechanisms promoting its pathogenicity, and its relevance to human sporadic AD., Competing Interests: Competing interests statement:C.J.W. is the author of patents PCT/US2016/049598, WO2017/040594, and PCT/US2019/017879. R.C. and K.L.B. are co-authors on patent PCT/US2019/017879. PCT/US2016/049598 and WO 2017/040594 are licensed by Cedars-Sinai Medical Center to T-Neuro Pharma, Inc. C.J.W. has received salary and ownership interest in T-Neuro Pharma, Inc.

Effective gene therapy for lung tissue requires the use of efficient vehicles to deliver the gene of interest into lung cells. When plasmid DNA encoding chloramphenicol acetyltransferase (CAT) was administered intranasally to BALB/c mice without carrier lipids, CAT activity was detected in mouse lung extracts. Plasmid DNA delivered with optimally formulated commercially available transfection reagents expressed up to 10-fold more CAT activity in lung than observed with naked DNA alone. Liposome formulations consisting of (+/-)-N-(3-aminopropyl)-N,N-dimethyl-2,3-bis (dodecyloxy)-1-propanaminium bromide (GAP-DLRIE) plus the neutral colipid dioleoylphosphatidylethanolamine (DOPE) enhanced CAT expression by more than 100-fold relative to plasmid DNA alone. A single administration of GAP-DLRIE liposome-CAT DNA complexes to mouse lung elicited peak expression at days 1-4 posttransfection, followed by a gradual return to baseline by day 21 postadministration. Readministration of GAP-DLRIE liposome CAT complexes at day 21 led to another transient peak of reporter gene expression. Histological examination of lungs treated with GAP-DLRIE complexed beta-galactosidase DNA revealed that alveolar epithelial cells were the primary locus of expression and that up to 1% of all alveoli contained epithelial cells expressing the transgene.

The tightly coupled nature of the reaction sequence catalyzed by monoterpene cyclases has precluded direct observation of the topologically required isomerization step leading from geranyl pyrophosphate to the presumptive, enzyme-bound, tertiary allylic intermediate linalyl pyrophosphate, which ultimately cyclizes to the various monoterpene skeletons. By using a partially purified monoterpene cyclase preparation and 2,3-cyclopropylgeranyl pyrophosphate, a substrate analog designed to uncouple the reaction sequence, the production of the corresponding tertiary homoallylic pyrophosphate isomer was demonstrated. This provides direct evidence for the usually cryptic isomerase component of the overall catalytic cycle. A number of other related products generated by reaction of cyclase with the analog were also identified, the structures and proportions of which were consistent with the intermediacy in catalysis of a cyclopropylcarbinyl cation X pyrophosphate anion pair. Kinetic parameters for the analog were compared with those of the natural substrate geranyl pyrophosphate. The results presented confirm mechanistic similarities in the enzymatic ionization and subsequent transformation of allylic pyrophosphate and cyclopropylcarbinyl pyrophosphate intermediates of isoprenoid metabolism.