Browsing by Author "Kelly P"

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    Anti-microbial peptide gene expression during oral vaccination: analysis of a randomized controlled trial.
    (2016-Nov) Simuyandi M; Kapulu M; Kelly P
    We have observed previously that micronutrient supplementation ameliorated suppression of α-defensin expression during diarrhoea. However, how interactions between anti-microbial peptide (AMP) expression and diarrhoeal disease are altered by micronutrient supplementation remain unclear. Using oral vaccination as a model of intestinal infection, we measured changes in AMP expression during multiple micronutrient supplementation. In the first part, volunteers underwent duodenal jejunal biopsy before and at 1, 2, 4 or 7 days after administration of one of three live, attenuated oral vaccines against rotavirus, typhoid and enterotoxigenic Escherichia coli. In the second part, participants were randomized to receive a multiple micronutrient supplement or placebo for 6 weeks before undergoing intestinal biopsy, vaccination against typhoid and rebiopsy after 14 days. Expression of human alpha-defensin (HD)5, HD6, hBD1, hBD2 and LL-37 was measured by quantitative reverse transcription-polymerase chain reaction. Taken together, the bacterial vaccines, but not rotavirus vaccine, reduced HD5 expression (P = 0·02, signed-rank test) and reduced LL-37 expression in seven of the eight individuals whose biopsies had expression prevaccination (P = 0·03). hBD2 was not detected. In the controlled trial, HD5 and HD6 expression after vaccination was lower [median ratio 0·5, interquartile range (IQR) = 0·07-2·2 and 0·58, IQR = 0·13-2·3, respectively] than before vaccination. There was no significant effect detected of micronutrient supplementation on expression of HD5, HD6, hBD1 or LL-37. We conclude that live attenuated bacterial vaccines, but not rotavirus vaccine, can reduce intestinal α-defensins, and typhoid vaccine reduced LL-37 expression. We found no evidence that micronutrient supplementation in the short term had any impact on anti-microbial peptide expression.
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    New Window Into Hepatitis B in Africa: Liver Sampling Combined With Single-Cell Omics Enables Deep and Longitudinal Assessment of Intrahepatic Immunity in Zambia.
    (2024-Nov-15) Musonda T; Wallace MS; Patel H; Martin OP; Oetheimer C; Mwakamui S; Sinkala E; Nsokolo B; Kanunga A; Lauer G; Chung RT; Wandeler G; Bhattacharya D; Kelly P; Alatrakchi N; Vinikoor MJ
    In Lusaka, Zambia, we introduced liver fine-needle aspiration biopsy (FNAB) into a research cohort of adults with treatment-naive chronic hepatitis B virus (HBV) infection, with and without human immunodeficiency virus (HIV) coinfection, as well as with acute HBV infection. From 117 enrollment and 47 longitudinal FNABs (at 1-year follow-up), we established participant acceptability and safety. We also demonstrated the quality of the material through single-cell RNA sequencing of selected enrollment FNAs, which revealed a range of immune cells. This approach can drive new insights into HBV immunology, informing cure strategies, and can improve our understanding of HBV natural history in Africa.