Fig 1.
Positive reinforcement training.
A) Acclimation to syringe for juice training. Male rhesus macaques (n = 7) were enrolled in a PRT program which used sweet liquids administered from a 60-cc catheter tip syringe as a reinforcer. Syringe acclimation was done over a period of three weeks, with training five days a week. Liquids tested included fruit juices (mango, apple, cranberry, passion fruit, pomegranate, and peach), diluted strawberry syrup, diluted molasses, vanilla ensure, kefir, yogurt and chocolate milk. Each individual animal is represented by a distinct shape/fill. B) Daily positive reinforcement training (PRT) time. Animal and trainer interactions were timed during training sessions with a stopwatch. Times when the animals did not successfully complete any desired behavior are included. Data shows results obtained over a two-month period when animals were trained to shift location in their cage, sit and accept liquid from a syringe. Individual daily training times are represented by circles; bars denote mean ± SEM.
Fig 2.
A) FTC and TAF stability in liquids. 200 mg of FTC, 15 mg of TAF, and 4% (w/v) natural bitterness masking powder (Fagron) were mixed into 30 ml of juice (peach, mango, grape, apple or Ensure) and vortexed until homogenous. Mixtures were tested for TAF and FTC concentrations by HPLC-MS/MS. Data is represented as ng of FTC or TAF per ml of liquid. B) FTC and TAF stability in solid foods. 200 mg of FTC, 15 mg of TAF, and 600 mg of bitterness masking powder were mixed well into 1 tablespoon of Nutella® or 1 tablespoon of peanut butter (PB). This mixture was divided and maintained at -20°, or -80° C for one week prior to testing by HPLC-MS/MS. Control samples were made at room temperature (23°) and analyzed immediately. Data is represented as ng of FTC/TAF per mg of solid food (PB or Nutella®). Temperature and storage time had no effect on the concentrations of FTC or TAF measured by HPLC-MS/MS.
Fig 3.
Adherence to daily oral FTC/TAF.
A) Drug adherence in trial I. PRT trained macaques (n = 6) were enrolled in a 30-day oral FTC/TAF adherence trial with Groups A and B housed in separate rooms. Animals were observed for daily consumption of ARVs. Days of drug administration are denoted in rows (one box = one day); the six animals are represented by the columns. Colors in the heat map reflect 100% of the dose eaten (green), 50% of dose eaten (yellow), and 0% of dose eaten (red). Animals were anesthetized twice a week for blood collection; FTC/TAF was given by oral gavage on these two days (gray boxes). Doses were not administered on weekends. B) Drug adherence in trial II. PRT-trained macaques (n = 4) were chosen for a second 30-day adherence trial. The only deviation from the first trial was the addition of honey to the drug delivery mixture. All macaques were housed in the same room. Drugs in this trial were also given on weekends. C) Dose consumption time during drug adherence trial II. Individual daily times are represented by filled shapes and bars denote the mean ± SD time for each animal. D) Changes in animal weight over the course of training. Animal weights were monitored prior to training, during PRT and throughout adherence trials. Longitudinal timeline of training and adherence trials are indicated.
Fig 4.
FTC-TP and TFV-DP concentrations in PBMCs.
Data reflects the concentrations of FTC-TP (A) and TFV-DP (B) measured in PBMCs from 4 macaques treated with daily oral FTC/TAF.
Fig 5.
Adherence during extended treatment.
A) Adherence heat map. Macaques (n = 4) were administered daily doses of FTC/TAF in a blended drug delivery mixture. Days of drug administration is denoted in columns (one box = one day) and the four animals in the rows. Colors in the heat map reflect 100% of the dose eaten (green), 50% of dose eaten (yellow), and 0% of dose eaten (red). Days of drug administration by gavage are not included in the adherence map. Day of spleen biopsy are indicated with gray boxes. B) Concentrations of FTC-TP and TFV-DP in PBMCs. FTC-TP and TFV-DP were stable during the first three months coinciding with high adherence to daily oral FTC/TAF. The period of suboptimal adherence is highlighted by gray bar. C) Plasma Cortisol levels. The gray area denotes the period of suboptimal adherence.