Mechanisms behind local immunosuppression using inhaled tacrolimus in preclinical models of lung transplantation

TY - JOUR

T1 - Mechanisms behind local immunosuppression using inhaled tacrolimus in preclinical models of lung transplantation

AU - Deuse, Tobias

AU - Blankenberg, Francis

AU - Haddad, Munif

AU - Reichenspurner, Hermann

AU - Phillips, Neil

AU - Robbins, Robert C

AU - Schrepfer, Sonja

PY - 2010/10

Y1 - 2010/10

N2 - Inhaled immunosuppression with tacrolimus (TAC) is a novel strategy after lung transplantation. Here we investigate the feasibility of tacrolimus delivery via aerosol, assess its immunosuppressive efficacy, reveal possible mechanisms of action, and evaluate its airway toxicity. Rats received 4 mg/kg TAC via oral or inhaled (AER) administration. Pharmacokinetic properties were compared, and in vivo airway toxicity was assessed. Full-thickness human airway epithelium (AE) was grown in vitro at an air-liquid interface. Equal TAC doses (10-1,000 ng) were either added to the bottom chamber (MED) or aerosolized for gas-phase exposure (AER). Airway epithelium TAC absorption, cell toxicity, and interactions of TAC with NFκB activation were studied. Single-photon emission computed tomography demonstrated a linear tracer accumulation within the lungs during TAC inhalation. The AER TAC generated higher lung-tissue concentrations, but blood concentrations that were 11 times lower. Airway histology and gene expression did not reveal drug toxicity after 3 weeks of treatment. In vitro AE exposed to TAC at 10-1,000 ng, orally or AER, maintained its pseudostratified morphology, did not show cell toxicity, and maintained its epithelial integrity, with tight junction formation. The TAC AER-treated AE absorbed the drug from the apical surface and generated lower-chamber TAC concentrations sufficient to suppress activated lymphocytes. Tacrolimus AER was superior to TAC MED at preventing AE IFN-γ, IL-10, IL-13, monocyte chemoattractant protein-1 chemokine (C-C motif) ligand 5 (RANTES) and TNF-α up-regulation. Tacrolimus inhibited airway epithelial cell NFκB activation. In conclusion, TAC can be delivered easily and effectively into the lungs without causing airway toxicity, decreases inflammatory AE cytokine production, and inhibits NFκB activation.

AB - Inhaled immunosuppression with tacrolimus (TAC) is a novel strategy after lung transplantation. Here we investigate the feasibility of tacrolimus delivery via aerosol, assess its immunosuppressive efficacy, reveal possible mechanisms of action, and evaluate its airway toxicity. Rats received 4 mg/kg TAC via oral or inhaled (AER) administration. Pharmacokinetic properties were compared, and in vivo airway toxicity was assessed. Full-thickness human airway epithelium (AE) was grown in vitro at an air-liquid interface. Equal TAC doses (10-1,000 ng) were either added to the bottom chamber (MED) or aerosolized for gas-phase exposure (AER). Airway epithelium TAC absorption, cell toxicity, and interactions of TAC with NFκB activation were studied. Single-photon emission computed tomography demonstrated a linear tracer accumulation within the lungs during TAC inhalation. The AER TAC generated higher lung-tissue concentrations, but blood concentrations that were 11 times lower. Airway histology and gene expression did not reveal drug toxicity after 3 weeks of treatment. In vitro AE exposed to TAC at 10-1,000 ng, orally or AER, maintained its pseudostratified morphology, did not show cell toxicity, and maintained its epithelial integrity, with tight junction formation. The TAC AER-treated AE absorbed the drug from the apical surface and generated lower-chamber TAC concentrations sufficient to suppress activated lymphocytes. Tacrolimus AER was superior to TAC MED at preventing AE IFN-γ, IL-10, IL-13, monocyte chemoattractant protein-1 chemokine (C-C motif) ligand 5 (RANTES) and TNF-α up-regulation. Tacrolimus inhibited airway epithelial cell NFκB activation. In conclusion, TAC can be delivered easily and effectively into the lungs without causing airway toxicity, decreases inflammatory AE cytokine production, and inhibits NFκB activation.

KW - Administration, Inhalation

KW - Animals

KW - Cell Survival/drug effects

KW - Cytokines/biosynthesis

KW - Epithelium/drug effects

KW - Gene Expression Regulation/drug effects

KW - Humans

KW - Immunoassay

KW - Immunosuppression

KW - Immunosuppressive Agents/administration & dosage

KW - Lung Transplantation

KW - Models, Animal

KW - Mucins/genetics

KW - NF-kappa B/metabolism

KW - Rats

KW - Rats, Inbred Lew

KW - Signal Transduction/drug effects

KW - Tacrolimus/administration & dosage

KW - Tomography, Emission-Computed, Single-Photon

U2 - 10.1165/rcmb.2009-0208OC

DO - 10.1165/rcmb.2009-0208OC

M3 - SCORING: Journal article

C2 - 19880819

VL - 43

SP - 403

EP - 412

JO - AM J RESP CELL MOL

JF - AM J RESP CELL MOL

SN - 1044-1549

IS - 4

ER -