Cytokine/Chemokine Release Patterns And Transcriptomic Profiles Of Lps/Ifn Gamma-Activated Human Macrophages Differentiated With Heat-Killed Mycobacterium Obuense, M-Csf, Or Gm-Csf

Macrophages (M phi s) are instrumental regulators of the immune response whereby they acquire diverse functional phenotypes following their exposure to microenvironmental cues that govern their differentiation from monocytes and their activation. The complexity and diversity of the mycobacterial cell wall have empowered mycobacteria with potent immunomodulatory capacities. A heat-killed (HK) whole-cell preparation of Mycobacterium obuense (M. obuense) has shown promise as an adjunctive immunotherapeutic agent for the treatment of cancer. Moreover, HK M. obuense has been shown to trigger the differentiation of human monocytes into a monocyte-derived macrophage (MDM) type named Mob-MDM. However, the transcriptomic profile and functional properties of Mob-MDMs remain undefined during an activation state. Here, we characterized cytokine/chemokine release patterns and transcriptomic profiles of lipopolysaccharide (LPS)/interferon gamma (IFN gamma)-activated human MDMs that were differentiated with HK M. obuense (Mob-MDM(LPS/IFN gamma)), macrophage colony-stimulating factor M-MDM(LPS/IFN gamma)), or granulocyte/macrophage colony-stimulating factor (GM-MDM(LPS/IFN gamma)). Mob-MDM(LPS/IFN gamma) demonstrated a unique cytokine/chemokine release pattern (interleukin (IL)-10(low), IL-12/23p40(low), IL-23p19/p40(low), chemokine (C-x-C) motif ligand (CXCL)9(low)) that was distinct from those of M-MDM(LPS/IFN gamma) and GM-MDM(LPS/IFN gamma). Furthermore, M-MDM(LPS/IFN gamma) maintained IL-10 production at significantly higher levels compared to GM-MDM(LPS/IFN gamma) and Mob-MDM(LPS/IFN gamma) despite being activated with M1-M phi-activating stimuli. Comparative RNA sequencing analysis pointed to a distinct transcriptome profile for Mob-MDM(LPS/IFN gamma) relative to both M-MDM(LPS/IFN gamma) and GM-MDM(LPS/IFN gamma) that comprised 417 transcripts. Functional gene-set enrichment analysis revealed significant overrepresentation of signaling pathways and biological processes that were uniquely related to Mob-MDM(LPS/IFN gamma). Our findings lay a foundation for the potential integration of HK M. obuense in specific cell-based immunotherapeutic modalities such as adoptive transfer of M phi s (Mob-MDM(LPS/IFN gamma)) for cancer treatment.