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Biology subjects

Headley, M. B.

Publications and source records attributed to Headley, M. B..

6 recordsLinked to original sources

NKTR-255, a polymer-conjugated IL-15, synergizes with CAR-T cell therapy to activate endogenous anti-tumor immunity and improve tumor control

CAR-T cells have yet to show widespread efficacy in solid tumors due in part to their poor persistence and loss of function in the tumor microenvironment. Further, heterogenous expression of most CAR target antigens in solid tumors can lead to escape of antigen-null tumors that resist CAR-T killing. Strategies to cooperatively boost both CAR-T and endogenous anti-tumor immunity could curb tumor escape and may be critical for achieving durable efficacy in cancer patients. NKTR-255 is a polymer-conjugated IL-15 with extended half-life that can boost endogenous T and NK cells, as well as CD19 CAR-T activity in B cell malignancies. However, whether NKTR-255 is sufficient to overcome CAR-T dysfunction in the suppressive solid tumor microenvironment, and how NKTR-255 and CAR-Ts together re-shape endogenous anti-tumor immunity, is not known. Using an autochthonous mouse model of ROR1+ lung adenocarcinoma, we show that NKTR-255 significantly boosted accumulation, reduced exhaustion, and improved function of tumor-infiltrating CAR-T cells. Compared with NKTR-255 or CAR-T treatment alone, combination of NKTR-255 and CAR-T therapy synergistically increased tumor-infiltrating CD11b+ cytotoxic NK cells, activated dendritic cells, and endogenous tumor-specific T cells that preserved a PD-1+Tcf1+ stem-like phenotype. Consequently, NKTR-255 and CAR-T combination therapy induced complete elimination of ROR1+ tumor and significantly improved survival, with enhanced tumor control dependent on activity of both CAR-Ts and endogenous T cells. Altogether, our data suggest that combining NKTR-255 with CAR-T therapy is a promising strategy to enhance both CAR-T and endogenous anti-tumor immunity to promote coordinated control of aggressive tumors.

immunology↗

Ontogeny and functional potential of founding dendritic cells in the developing lung

Lung development begins in utero and reaches full maturity post birth. Dendritic cells (DC) play a key role in immune regulation in lungs. However, comprehensive exploration of DCs in these immature lungs has not been performed. Here we explored DCs from fetal to newborn mouse lungs phenotypically, ontogenetically, transcriptomically and functionally and found two DC subsets, resembling adult cDC1 and cDC2, but with key differences. Phenotypically, fetal-cDC1 lacks the classical-DC1 (cDC1) marker XCR1, while the fetal-cDC2 express both cDC-associated genes as well as monocyte-derived DC genes. Both DC subsets wane as lungs enter the alveolar stage, giving way to the more familiar adult cDC1 and cDC2. Both fetal-cDC1 and fetal-cDC2 derive from ED14.5 fetal liver Macrophage Dendritic Progenitors, not from monocytes or classic Precursor-cDC (Pre-cDC), indicating a unique ontogeny of first DCs in developing mouse lungs. Together we provide the first in depth exploration of first DCs in developing lungs.

immunology↗

Uptake of tumor-derived microparticles induces metabolic reprogramming of macrophages in the early metastatic lung.

The formation of a pre-metastatic niche is a critical step during the metastatic spread of cancer. One way by which primary tumors prime host cells at future metastatic sites is through local shedding of tumor-derived microparticles as a consequence of vascular sheer flow. However, it remains unclear how the uptake of such particles by resident immune cells affects their phenotype and function. Here we show that ingestion of tumor-derived microparticles by macrophages induces a rapid metabolic and phenotypic switch that is characterized by enhanced mitochondrial mass and function, increased oxidative phosphorylation and upregulation of cellular adhesion molecules resulting in reduced motility in the early metastatic lung. We show that this reprogramming event is dependent on signaling through the mTORC1, but not mTORC2 pathway, and is unique to uptake of tumor-derived microparticles. Together, these data support a mechanism by which uptake of tumor-derived microparticles induces reprogramming of macrophages to shape their fate and function in the early metastatic lung.

immunology↗

Infinity Flow: High-throughput single-cell quantification of 100s of proteins using conventional flow cytometry and machine learning

Modern immunologic research increasingly requires high-dimensional analyses in order to understand the complex milieu of cell-types that comprise the tissue microenvironments of disease. To achieve this, we developed Infinity Flow combining hundreds of overlapping flow cytometry panels using machine learning to enable the simultaneous analysis of the co-expression patterns of 100s of surface-expressed proteins across millions of individual cells. In this study, we demonstrate that this approach allows the comprehensive analysis of the cellular constituency of the steady-state murine lung and to identify novel cellular heterogeneity in the lungs of melanoma metastasis bearing mice. We show that by using supervised machine learning, Infinity Flow enhances the accuracy and depth of clustering or dimensionality reduction algorithms. Infinity Flow is a highly scalable, low-cost and accessible solution to single cell proteomics in complex tissues.

immunology↗

Pulmonary natural killer cells control neutrophil intravascular motility and response to acute inflammation

The pulmonary immune system defends a huge surface area directly in contact with the contents of the air we breathe. Neutrophils, the most abundant immune cell in the pulmonary vasculature, are critical to immunity but they are also capable of generating life-threatening pathology. Natural Killer cells are the most highly represented lymphocyte subset in the lung, but relatively little is known about their localization, motility or the specific mechanisms by which they contribute to local homeostasis. Here, we used lung-intravital microscopy to directly visualise and quantify neutrophil and natural killer cell dynamics in the pulmonary vasculature of live mice. This approach revealed unexpected sessile behaviour by intravascular natural killer cells. Interactions with natural killer cells made neutrophils scan the endothelium more slowly over larger distances and reduced the number of neutrophils that accumulated in an LPS-triggered inflammatory challenge. This represents a new paradigm by which natural killer cells contribute to lung physiology by diminishing potentially pathogenic neutrophil accumulation.

immunology↗

Chimeric antigen receptors that trigger phagocytosis

Chimeric antigen receptors (CARs) are synthetic receptors that reprogram T cells to kill cancer. The success of CAR-T cell therapies highlights the promise of programmed immunity, and suggests that applying CAR strategies to other immune cell lineages may be beneficial. Here, we engineered a family of Chimeric Antigen Receptors for Phagocytosis (CAR-Ps) that direct macrophages to engulf specific targets, including cancer cells. CAR-Ps consist of an extracellular antibody fragment, which can be modified to direct CAR-P activity towards specific antigens. By screening a panel of engulfment receptor intracellular domains, we found that the cytosolic domains from Megf10 and FcR{gamma} robustly triggered engulfment independently of their native extracellular domain. We show that CAR-Ps drive specific engulfment of antigen-coated synthetic particles and whole cancer cells. Addition of a tandem PI3K recruitment domain increased cancer cell engulfment. Finally, we show that CAR-P expressing macrophages reduce cancer cell number in co-culture by over 40%.\n\nSummaryWe report the first Chimeric Antigen Receptors for Phagocytosis (CAR-Ps) that promote engulfment of antigen-coated particles and cancer cells.

cell biology↗