Project description:To understand the mechanistic basis of local innate and adaptive immunity against infectious bronchitis virus (IBV) at the molecular level, we examined the gene transcription profile of tracheal epithelial layers at 3 days after infection of chickens with an attenuated IBV-Massachusetts strain. Keywords: Disease State Analysis, Early mucosal immune response, FHCRC 13k chicken array
Project description:Immunological mechanisms of susceptibility to NTM disease are poorly understood. We evaluated innate and antigen-specific adaptive immune responses to Mycobacterium avium complex in individuals with MAC lung disease. We investigated the gene expression changes induced in PBMCs by polyclonal stimulation (anti-CD3, anti-CD28), Mav and Mtb lysates and a peptide pool (MTB300) in individuals with MAC lung disease (MACDZ), and healthy controls (IGRA+ and IGRA-).
Project description:Macrophage-directed immunotherapy has emerged as a promising strategy to eliminate tumors by unleashing phagocytosis, exemplified by blockade of the CD47-SIRPα “don’t eat me” axis. However, despite robust enhancement of phagocytosis, such approaches often fail to generate durable antitumor immunity in solid tumors, highlighting a critical disconnect between innate immune activation and effective T cell responses. Here, we identify PCSK9 as an adaptive resistance factor induced by macrophage immune checkpoint blockade. Tumor-derived PCSK9 promotes lysosomal degradation of MHC-I in macrophages, thereby impairing antigen cross-presentation and limiting CD8⁺ T cell priming. This previously unrecognized mechanism reveals how phagocytosis-targeted therapies can paradoxically suppress adaptive immunity. To overcome this resistance, we engineered bispecific fusion proteins that concurrently target the CD47-SIRPα phagocytosis checkpoint and the PCSK9–MHC-I antigen presentation axis, among which SIRPαD1-αPCSK9 emerged as the optimal format. Dual targeting synergistically enhances macrophage phagocytosis, preserves antigen cross-presentation capacity, and reprograms the tumor microenvironment toward an immunostimulatory state. Consequently, SIRPαD1-αPCSK9 elicits robust activation of both innate and adaptive antitumor immunity, leading to potent tumor control with improved safety. These findings uncover a novel mechanism of resistance to macrophage-centered immunotherapy and establish a rational dual-targeting strategy that bridges phagocytosis and T cell activation, offering a new paradigm for macrophage-driven cancer immunotherapy.
Project description:Lymph nodes (LNs) enable innate defense to limit pathogen dissemination while also driving adaptive immunity. Yet, certain innate responses can restrict adaptive processes, suggesting that these must be tightly regulated. Here, we report that after infection or immunization, LN architecture is rapidly altered, with large-scale, polarized recruitment of neutrophils and monocytes from inflamed blood vessels, and intranodal repositioning of NK cells. Mechanistically, dendritic cells (DCs) promote this process through expression of inflammatory chemokines and integrin ligands. While necessary for efficient pathogen containment, DC-driven innate cell responses paradoxically limit early adaptive immunity, with infiltrating neutrophils displacing lymphocytes and reducing the LN area available for T cell priming. Upon threat secession however, DCs and DC-recruited monocytes phagocytose the neutrophils, restoring tissue architecture and generating polarized domains for downstream adaptive immune cell activation. Thus, DCs orchestrate innate cell organization during inflammation, serving as rheostats of innate versus adaptive functions of the LN.