Resistance and augmentation of innate immunity in mice exposed to starvation

Mice were exposed to starvation for 3 days. Body temperature and various parameters were examined. By starvation, body temperature, blood glucose and ACTH decreased, especially on days 2 and 3. The level of corticosterone increased at this time. On the other hand, the number of lymphocytes yielded by the liver, spleen and thymus decreased from day 1 to 3. The change of the distribution of lymphocyte subsets was unique because NK, NKT and extrathymic T cells were stress-resistant in the liver. Conventional T and B cells were stress-sensitive. Reflecting the increased proportion of NK and NKT cells, NK and NKT activities were augmented. The increased proportion of NKT cells produced both IFNγ and IL-4 (Th0-type profile). The proportion and some functions of granulocytes and macrophages increased on Day 1 after starvation. These results suggest that starvation has a potential to increase the functions of unconventional lymphocytes and myeloid cells.