- 作者: Pa T Ngom; Juan Solon; Sophie E Moore; Gareth Morgan; Andrew M Prentice; Richard Aspinall
- 作者服務機構: Nutrition Programme, MRC Laboratories, The Gambia, West Africa
- 中文摘要: --
- 英文摘要:
Background: The study exploits a natural human experimental model of subsistence farmers experiencing chronic and seasonally modified food shortages and infectious burden. Two seasons existed, one of increased deprivation and infections (Jul-Dec), another of abundance and low infections (Jan-Jun); referred to as the hungry/high infection and harvest/low infection seasons respectively. Prior analysis showed a 10-fold excess in infectious disease associated mortality in young adults born in the hungry/high infection versus harvest/low infection season, and reduced thymic output and T cell counts in infancy. Here we report findings on the role of early life stressors as contributors to the onset of T cell immunological defects in later life.
Methods: We hypothesised that season of birth effects on thymic function and T cell immunity would be detectable in young adults since Kaplan-Meier survival curves indicated this to be the time of greatest mortality divergence. T cell subset analyses by flow-cytometry, sjTRECs, TCRVb repertoire and telomere length by PCR, were performed on samples from 60 males (18-23y) selected to represent births in the hungry/high infection and harvest/low infection
Results: Total lymphocyte counts were normal and did not differ by birth season. CD3+ and CD4+ but not CD8+ counts were lower for those born during the hungry/high infection season. CD8+ telomere length also tended to be shorter. Overall, CD8+ TCRVb repertoire skewing was observed with 'public' expressions and deletions seen in TCRVb12/22 and TCRVb24, respectively but no apparent effect of birth season.
Conclusions: We conclude that, although thymic function was unchanged, the CD4+ and CD3+ counts, and CD8+ telomere length results suggested that aspects of adult T cell immunity were under the influence of early life stressors. The endemicity of CMV and HBV suggested that chronic infections may modulate immunity through T cell repertoire development. The overall implications being that, this population is at an elevated risk of premature immunosenescence possibly driven by a combination of nutritional and infectious burden.
- 中文關鍵字: --
- 英文關鍵字: --