Interactions of aging and annual rhythms on the recovery of cryopreserved murine splenic lymphocytes.
The physiological status of donor organisms is an often overlooked factor in cryopreservation experiments. Murine splenic lymphocytes exhibit systematic changes in function which are endogenous and influence recoveries of viable and functional frozen-thawed cells over the life span of mice. One of these changes is the decline in the performance of unfrozen cells as organisms age. Superimposed on the age-related decline in lymphocyte functions are circannual rhythms in T- and B-cell mitogenesis, and the properties of these rhythms also change with age. Splenocytes from young, 15-month-old and 23- to 27-month-old C57BL/6 mice were cryopreserved and tested for recovery of mitogenic responses to activation by the T-cell mitogens, phytohemagglutinin and concanavalin A, and the B-cell mitogen, lipopolysaccharide. Tritiated thymidine incorporation by activated, dividing cells was determined after 72 hr of in vitro culture. Seasonal patterns in recovery of viable and functional cryopreserved cells from young mice resembled those of their unfrozen controls (6). By 15 months of age, the responses after freeze-thaw stress decreased to the levels observed for cells obtained from senescent mice, and seasonal patterns were no longer observed. In these middle-aged mice, intracellular changes in lymphocytes that are equivalent to those in senescent animals resulted in irreparable structural-functional injury during cryopreservation.
Brock
M A
MA
Clinical Immunology Section, National Institute on Aging, Baltimore, Maryland 21224.
Adler
W H
WH
D000375:Aging / Q000502:physiology*; D000818:Animals; D002478:Cells, Cultured; D002940:Circadian Rhythm; D005260:Female; D005615:Freezing; D008214:Lymphocytes / Q000166:cytology / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D011309:Preservation, Biological; D013154:Spleen / Q000166:cytology