Altered Polarization and Impaired Phagocytic Activity of Lung Macrophages in People With Human Immunodeficiency Virus and Chronic Obstructive Pulmonary Disease

Area of Science:

• Immunology
• Pulmonology
• Infectious Diseases

Background:

• People with human immunodeficiency virus (PWH) face a higher risk of developing chronic obstructive pulmonary disease (COPD).
• Understanding the immune mechanisms underlying COPD in PWH is crucial for managing disease progression.

Purpose of the Study:

• To investigate lung macrophage phenotypes and their phagocytic capacity in PWH with and without COPD.
• To identify specific macrophage subsets associated with COPD development in PWH.

Main Methods:

• Lung macrophages were phenotyped into four subgroups: M1, M2, double positives, and double negatives (CD40 and CD163 expression).
• Phagocytic capacity of these macrophage subsets was assessed in PWH with COPD, PWH without COPD, and healthy controls.

Main Results:

• PWH with COPD exhibited a significantly higher proportion of double-negative macrophages (84.1%) compared to PWH without COPD (54.3%) and controls (23.9%).
• Double-negative macrophages demonstrated the poorest phagocytic capacity.
• Reduced overall phagocytosis was observed in PWH with COPD.

Conclusions:

• An abundance of nonpolarized (double-negative) macrophages characterizes PWH with COPD.
• These macrophages possess impaired phagocytic function, contributing to increased susceptibility to lung disease progression in PWH.
• Targeting these non-functional macrophages may offer a therapeutic strategy for COPD in PWH.