{'fraction_non_alphanumeric': 0.04938271604938271, 'fraction_numerical': 0.03292181069958848, 'mean_word_length': 5.235042735042735, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Impact of activated T cells on rat skeletal muscle satellite cell function

Sarcopenia is an age‐associated loss of skeletal muscle mass and strength. Recent evidence suggests that an age‐associated loss of satellite cell functionality contributes to sarcopenia. Current research also suggests that T cells of the immune system may play a role in skeletal muscle repair via signaling with satellite cells. The objective of the present study was to further examine the influence of activated T cells on satellite cells. Satellite cells were collected from the gastrocnemius and plantaris from 3‐(young) and 32‐mo‐old (old) animals and T cells were harvested from the spleen of using Dynabead isolation with anti‐CD3. T cells were activated for 48 hours with co‐stimulation of 100 IU/ml Interleukin‐2 (IL‐2) and 5 μg/ml of anti‐CD28. Co‐stimulation increased 5‐bromo‐2′‐deoxyuridine (BrdU) incorporation (proliferation) of T cells from 15.27% (SEM=7.93, n=3) in control to 61.97% (SEM= 10.52, n=3). Additionally, T cell cytokines increased satellite cell proliferation by 23.98% (SEM=5.69, n=4) in young satellite cells but decreased by 0.69% (SEM=5.65, n=3) in old satellite cells. These data suggest that aging may alter T cell‐induced satellite cell function. These findings have implications for developing strategies aimed at increasing satellite cell proliferation and the regenerative capacity of aged skeletal muscle. Supported by Colorado Space Grant.