The proportion of CD45RA(+)CD62L(+) (quiescent-phenotype) T cells within the CD8(+) subset increases in advanced weight loss in the protein- or energy-deficient weanling mouse.
Male and female C57BL/6J mice, initially 19 d old, had free access to a complete purified diet, were fed this diet in restricted daily quantities, or had free access to a low-protein diet. Three separate studies were conducted with feeding periods of 14, 9 or 6 d (n = 7-8 per dietary group and feeding period; 6 d: restricted intake and age-matched controls only). A zero-time control group (19 d old) was included in each study. Malnourished mice lost approximately 2% of initial body weight daily. Naïve-phenotype (quiescent) CD8(+) T cells of the blood, spleen and mesenteric lymph nodes were identified on the basis of surface coexpression of CD45RA and CD62L. Relative to age-matched controls, the percentage of naïve-phenotype CD8(+) T cells was high in energy-restricted groups after 9 d and 14 d of weight loss and in the protein-restricted groups after 14 d (P < or = 0.05). No ontogenetic change was apparent (age-matched vs. zero-time control). Other studies have demonstrated depression in cell-mediated immune competence in both malnutrition models within the first week of weight loss. An overabundance of quiescent-phenotype T cells within the involuted CD8(+) compartment may contribute to established immune depression but not to its initiation in weight loss pathologies.
ten Bruggencate
S J
SJ
Department of Human Biology and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
Hillyer
L M
LM
Woodward
B D
BD
D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D018753:Diet, Protein-Restricted; D002149:Energy Intake; D005260:Female; D005508:Food Deprivation; D019041:L-Selectin / Q000032:analysis*; D017493:Leukocyte Common Antigens / Q000032:analysis*; D008198:Lymph Nodes / Q000166:cytology; D018655:Lymphocyte Count; D008297:Male; D008643:Mesentery; D051379:Mice; D008810:Mice, Inbred C57BL; D009748:Nutrition Disorders / Q000276:immunology*; D011488:Protein Deficiency / Q000276:immunology; D013154:Spleen / Q000166:cytology; D015431:Weight Loss
D019041:L-Selectin; D017493:Leukocyte Common Antigens