DECREASED INTERLEUKIN-2 PRODUCTION FROM CULTURED PERIPHERAL-BLOOD MONONUCLEAR-CELLS IN HUMAN ACUTE STARVATION

Depressed cell-mediated immunity and decreased insulin-like growth fac tor I (IGF-I) are observed in malnourished humans. To study the intera ction among nutrition, IGF-I, and cytokines, healthy volunteers (six m en and four women, aged 21-38 yr, weighing 93-124% of ideal body weigh t) were subjected to a 7-day fast (mineral water only). Pasting steadi ly decreased serum IGF-I from 247 +/- 29 (prefast) to 87 +/- 10 ng/mL (postfast; P < 0.0001), total T cells (CD3+) from 1499 +/- 68 to 1308 +/- 70 x 10(9) (P < 0.0001), and T helper cells (CD4+) from 997 +/- 62 to 856 +/- 55 x 10(9) (P < 0.001). Peripheral blood mononuclear cells were isolated and cultured in serum-free RPMI 1640 for 24 h. Pasting attenuated peripheral blood mononuclear cell production of interleukin -2 in response to various concentrations of phytohemagglutinin P [PHA- P; 347 +/- 48 (prefast) us. 135 +/- 52 pg/mL (postfast) when challenge d with 3 mu g/mL PHA-P; P < 0.005 when comparing dose-response curves (1-100 mu g/mL PHA-P)]. Although the approximately 3-fold suppression of interleukin-2 and IGF-I in subjects fasted for 1 week is not likely to affect immune function significantly, our results with this short term model of nutrient restriction provide insight into possible mecha nisms for immune suppression in chronic starvation.