Publications
Department of Medicine faculty members published more than 3,600 peer-reviewed articles in 2024.
2015
2015
2015
The immune suppressive protein CTLA-4 is constitutively expressed by Tregs and induced in effector T cells upon activation. Its crucial role in adaptive immunity is apparent from the fatal autoimmune pathology seen in CTLA-4 knockout mice. However, little is known regarding factors that regulate CTLA-4 expression and their effect upon its function to remove CD80 and CD86 from antigen presenting cells by transendocytosis. Th17 cells are emerging as significant players in autoimmunity as well as other diseases. Therefore, in this study we have examined the effects of Th17 polarising conditions on CTLA-4 expression and function in human T cells and show that Th17 conditions can suppress the expression of CTLA-4 and its transendocytic function. In contrast to Th17 cells, vitamin D is inversely associated with autoimmune disease. We have previously shown a striking ability of 1,25 dihydroxyvitamin D3 (1,25(OH)2D3) to enhance CTLA-4, however, its effects upon B7 transendocytosis and its activity in the context of inflammation remained unknown. Here we show that induction of CTLA-4 by 1,25(OH)2D3 can actually be enhanced in the presence of Th17 polarising cytokines. Furthermore, its transendocytic function was maintained such that T cells generated in the presence of Th17 conditions and 1,25(OH)2D3 were highly effective at capturing CTLA-4 ligands from antigen presenting cells and suppressing T cell division. Taken together, these data reveal an inhibitory effect of Th17 polarising conditions upon CTLA-4-mediated regulation and show that 1,25(OH)2D3 counteracts this effect. Given the importance of CTLA-4-mediated suppression in the control of autoimmune diseases, our novel data highlight the importance of vitamin D in inflammatory settings.
View on PubMed2015
2015
2015
2015
2015
2015
Current pharmacological therapy for Alzheimer's disease (AD) includes the cholinesterase inhibitors (ChEIs) donepezil, rivastigmine, and galantamine and the N-methyl D-aspartate receptor antagonist memantine. Based on the results of randomized controlled trials and several meta-analyses, ChEIs appear to show modest but statistically significant improvements on several measures, including cognition and global functioning. Given their modest effects, there is a lack of consensus among clinicians regarding issues related to initiation, optimal duration, and discontinuation of ChEI therapy across the spectrum of AD. There is evidence from long-term observational controlled studies that early initiation and persistent exposure to AD therapy lead to delays in nursing home admission and significantly slower rates of cognitive and functional impairment. In the moderate to severe stages of AD, therapeutic trials of higher dose ChEIs and the addition of memantine are recommended for patients who are no longer responding to lower doses. While side effects are generally mild and gastrointestinal in nature, these events can lead to significant morbidity in more susceptible patients with advanced disease. Patients should thus be regularly monitored for any potential serious side effects of ChEI therapy, which also may include syncope and bradycardia. At the terminal stages of AD, such as when patients become hospice eligible, attempts to cautiously discontinue all medications not necessary for quality of life, including AD drugs, should be made.
View on PubMed2015