Anti-inflammatory effects of lenabasum, a cannabinoid receptor type 2 agonist, on macrophages from cystic fibrosis.

BACKGROUND: Lenabasum is an oral synthetic cannabinoid receptor type 2 agonist previously shown to reduce the production of key airway pro-inflammatory cytokines known to play a role in cystic fibrosis (CF). In a double-blinded, randomized, placebo-control phase 2 study, lenabasum lowered the rate of pulmonary exacerbation among patients with CF. The present study was undertaken to investigate anti-inflammatory mechanisms of lenabasum exhibits in CF macrophages. METHODS: We used monocyte-derived macrophages (MDMs) from healthy donors (n = 15), MDMs with CFTR inhibited with C-172 (n = 5) and MDMs from patients with CF (n = 4). Monocytes were differentiated to macrophages and polarized into classically activated (M1) macrophages by LPS or alternatively activated (M2) macrophages by IL-13 in presence or absence of lenabasum. RESULTS: Lenabasum had no effect on differentiation, polarization and function of macrophages from healthy individuals. However, in CF macrophages lenabasum downregulated macrophage polarization into the pro-inflammatory M1 phenotype and secretion of the pro-inflammatory cytokines IL-8 and TNF-α in a dose-dependent manner. An improvement in phagocytic activity was also observed following lenabasum treatment. Although lenabasum did not restore the impaired polarization of anti-inflammatory M2 macrophage, it reduced the levels of IL-13 and enhanced the endocytic function of CF MDMs. The effects of lenabasum on MDMs with CFTR inhibited by C-172 were not as obvious. CONCLUSION: In CF macrophages lenabasum modulates macrophage polarization and function in vitro in a way that would reduce inflammation in vivo. Further studies are warranted to determine the link between activating the CBR2 receptor and CFTR.

Quantitative humoral profiling of the HIV-1 proteome in elite controllers and patients with very long-term efficient antiretroviral therapy.

A major challenge in evaluating the success of HIV eradication approaches is the need for accurate measurement of persistent HIV during effective antiretroviral therapy (ART). Previous studies have reported that the anti-HIV antibody assay "luciferase immuno-precipitation systems (LIPS)" can distinguish HIV-infected individuals harboring different sizes of the viral reservoirs. We performed antibody profiling of HIV-1 proteomes using LIPS in viremic progressors (n = 38), elite controllers (ECs; n = 19) and patients with fully suppressive long-term antiretroviral therapy (ART) (n = 19) (mean 17 years). IgG was quantified against six HIV-1 fusion proteins: p24, gp41, RT, Tat, integrase and protease. Lower antibody levels to all six-fusion proteins were observed in long-term ART patients compared to viremics (p < 0.05). In contrast ECs had lower antibody levels only against Tat and Integrase (p < 0.05). Principal component analysis and cluster-network analysis identified that 68% (13/19) of the long-term ART patients clustered together with 26% (5/19) ECs. The remaining ECs clustered together with the viremics indicating non-homogeneity among the ECs. The low anti-HIV levels in the long-term treated patients may indicate a restricted remaining viral replication. In contrast, the higher levels in ECs suggest a continuous viral expression with a limited concomitant release of extracellular virus.