MONOCYTE FUNCTION FOLLOWING ACUTE EXERCISE IN BREAST CANCER SURVIVORS BEFORE AND AFTER EXERCISE TRAINING

Abstract

Breast cancer therapy impairs immune function that may be attenuated with exercise, though the specific changes that occur remain unclear. PURPOSE: 1) To examine monocyte function in breast cancer survivors (BCS) following acute exercise and 2) to determine if this response changes with exercise training. METHODS: 9 BCS [Age: 58±8, BMI: 27.9±6.7] completed a cardiopulmonary exercise test (CPET). In a subsequent trial, 45 min of intermittent cycling at 60% of CPET peak wattage was performed. Blood was taken at rest, immediately (0h) and 1h after exercise. Monocyte phagocytosis and oxidative burst were assessed following E.coli exposure. Toll-like receptor 2 (TLR2) and 4 (TLR4) expression was determined on CD14+CD16- and CD14+CD16+ monocytes. All assays were performed before (pre) and after (post) 16 wk of combined aerobic and resistance training. Data are presented as mean fluorescence intensity ± SD. RESULTS: Phagocytosis increased 1h after acute exercise before (rest: 3396±941 0h: 3257±772, 1h: 3692±824, p=0.035) but not after training. There was a trend for greater phagocytosis with training (pre: 3533±815 post: 5027±2039, p=0.078). Oxidative burst was unchanged with acute exercise but improved following training (pre: 4264±1061 post: 5446±1287, p=0.026). CD16- TLR2 expression decreased acutely at 1h compared to rest and 0h both before and after training (rest: 350±70, 0h: 328±73, 1h: 287±41, both p<0.05) while CD16+ decreased acutely before training only (pre rest: 355±115 0h: 339±98 1h: 291±87. CD16- TLR4 expression tended to decrease with acute exercise (p=0.067) whereas CD16+ TLR4 expression decreased across all time points (rest: 140±15, 0h: 135±15, 1h: 123±18, all p<0.05) with neither population affected by training. CONCLUSIONS: In BCS, monocyte phagocytic capacity of bacteria increased following acute exercise, while training increased both phagocytosis and oxidative burst. Training appeared to mitigate the acute response, possibly due to higher resting function. Expression of TLR2 and TLR4 were progressively reduced with acute exercise that was mostly independent of training. The reduction of monocyte TLR2 and TLR4 may represent an anti-inflammatory response to acute exercise that promotes enhanced elimination of bacteria. Supported by Breast Cancer Research Foundation (New York, NY).