The poor efficacy of systemic cancer therapeutics in pancreatic ductal adenocarcinoma (PDAC) is partly attributed to deposition of collagen and hyaluronan, leading to interstitial hypertension ...collapsing blood and lymphatic vessels, limiting drug delivery. The intrinsic micro-regional interactions between hyaluronic acid (HA), collagen and the spatial origins of mechanical stresses that close off blood vessels was investigated here. Multiple localized pressure measurements were analyzed with spatially-matched histochemical images of HA, collagen and vessel perfusion. HA is known to swell, fitting a linear elastic model with total tissue pressure (TTP) increasing above interstitial fluid pressure (IFP) directly with collagen content. However, local TTP appears to originate from collagen area fraction, as well as increased its entropy and fractal dimension, and morphologically appears to be maximized when HA regions are encapsulated by collagen. TTP was inversely correlated with vascular patency and verteporfin uptake, suggesting interstitial hypertension results in vascular compression and decreased molecular delivery in PDAC. Collagenase injection led to acute decreases in total tissue pressure and increased drug perfusion. Large microscopic variations in collagen distributions within PDAC leads to microregional TPP values that vary on the hundred micron distance scale, causing micro-heterogeneous limitations in molecular perfusion, and narrows viable treatment regimes for systemically delivered therapeutics.
Early identification of cerebral palsy (CP) during infancy will provide opportunities for early therapies and treatments. The aim of the present study was to present a novel machine-learning model, ...the Computer-based Infant Movement Assessment (CIMA) model, for clinically feasible early CP prediction based on infant video recordings.
The CIMA model was designed to assess the proportion (%) of CP risk-related movements using a time-frequency decomposition of the movement trajectories of the infant's body parts. The CIMA model was developed and tested on video recordings from a cohort of 377 high-risk infants at 9-15 weeks corrected age to predict CP status and motor function (ambulatory vs. non-ambulatory) at mean 3.7 years age. The performance of the model was compared with results of the general movement assessment (GMA) and neonatal imaging.
The CIMA model had sensitivity (92.7%) and specificity (81.6%), which was comparable to observational GMA or neonatal cerebral imaging for the prediction of CP. Infants later found to have non-ambulatory CP had significantly more CP risk-related movements (median: 92.8%,
= 0.02) compared with those with ambulatory CP (median: 72.7%).
The CIMA model may be a clinically feasible alternative to observational GMA.
Following an acute insult, macrophages regulate renal fibrogenesis through the release of various factors that either encourage the synthesis of extracellular matrix synthesis or the degradation of ...matrix
endocytosis, proteolysis, or both. However, the roles of infiltrating versus resident myeloid cells in these opposing processes require elucidation. The transcription factor Twist1 controls diverse essential cellular functions through induction of several downstream targets, including matrix metalloproteinases (MMPs). In macrophages, Twist1 can influence patterns of cytokine generation, but the role of macrophage Twist1 in renal fibrogenesis remains undefined.
To study Twist1 functions in different macrophage subsets during kidney scar formation, we used two conditional mutant mouse models in which
was selectively ablated either in infiltrating, inflammatory macrophages or in resident tissue macrophages. We assessed fibrosis-related parameters, matrix metallopeptidase 13 (MMP13, or collagen 3, which catalyzes collagen degradation), inflammatory cytokines, and other factors in these Twist1-deficient mice compared with wild-type controls after subjecting the animals to unilateral ureteral obstruction. We also treated wild-type and Twist1-deficient mice with an MMP13 inhibitor after unilateral ureteral obstruction.
Twist1 in infiltrating inflammatory macrophages but not in resident macrophages limited kidney fibrosis after ureteral obstruction by driving extracellular matrix degradation. Moreover, deletion of Twist1 in infiltrating macrophages attenuated the expression of MMP13 in CD11b
Ly6C
myeloid cells. Inhibition of MMP13 abrogated the protection from renal fibrosis afforded by macrophage Twist1.
Twist1 in infiltrating myeloid cells mitigates interstitial matrix accumulation in the injured kidney by promoting MMP13 production, which drives extracellular matrix degradation. These data highlight the complex cell-specific actions of Twist1 in the pathogenesis of kidney fibrosis.
Undifferentiated monocytes can be loaded with tumor antigens (Ag) and administered intravenously to induce antitumor cytotoxic T lymphocyte (CTL) responses. This vaccination strategy exploits an ...endogenous Ag cross-presentation pathway, where Ag-loaded monocytes (monocyte vaccines) transfer their Ag to resident splenic dendritic cells (DC), which then stimulate robust CD8 + CTL responses. In this study, we investigated whether monocyte vaccination in combination with CDX-301, a DC-expanding cytokine Fms-like tyrosine kinase 3 ligand (Flt3L), could improve the antitumor efficacy of anti-programmed cell death (anti-PD-1) immune checkpoint blockade. We found that Flt3L expanded splenic DC over 40-fold in vivo and doubled the number of circulating Ag-specific T cells when administered before monocyte vaccination in C57BL/6 mice. In addition, OVA-monocyte vaccination combined with either anti-PD-1, anti-programmed cell death ligand 1 (anti-PD-L1), or anti-cytotoxic T lymphocyte antigen-4 (anti-CTLA-4) suppressed subcutaneous B16/F10-OVA tumor growth to a greater extent than checkpoint blockade alone. When administered together, OVA-monocyte vaccination improved the antitumor efficacy of Flt3L and anti-PD-1 in terms of circulating Ag-specific CD8 + T cell frequency and inhibition of subcutaneous B16/F10-OVA tumor growth. To our knowledge, this is the first demonstration that a cancer vaccine strategy and Flt3L can improve the antitumor efficacy of anti-PD-1. The findings presented here warrant further study of how monocyte vaccines can improve Flt3L and immune checkpoint blockade as they enter clinical trials.
Preferential homing of naive lymphocytes to secondary lymphoid organs is thought to involve the action of chemokines, yet no chemokine has been shown to have either the expression pattern or the ...activities required to mediate this process. Here we show that a chemokine represented in the EST database, secondary lymphoid-tissue chemokine (SLC), is expressed in the high endothelial venules of lymph nodes and Peyer's patches, in the T cell areas of spleen, lymph nodes, and Peyer's patches, and in the lymphatic endothelium of multiple organs. SLC is a highly efficacious chemoattractant for lymphocytes with preferential activity toward naive T cells. Moreover, SLC induces firm adhesion of naive T lymphocytes via β 2 integrin binding to the counter receptor, intercellular adhesion molecule-1, a necessary step for lymphocyte recruitment. SLC is the first chemokine demonstrated to have the characteristics required to mediate homing of lymphocytes to secondary lymphoid organs. In addition, the expression of SLC in lymphatic endothelium suggests that the migration of lymphocytes from tissues into efferent lymphatics may be an active process mediated by this molecule.
Strategies that enhance the host antitumor immune response promise to revolutionize cancer therapy. Optimally mobilizing the immune system will likely require a multi-pronged approach to overcome the ...resistance developed by tumors to therapy. Recently, it has become recognized that doxorubicin can contribute to re-establishing host antitumor immunity through the generation of immunogenic cell death. However, the potential for delivery strategies to further enhance the immunological effects of doxorubicin has not been adequately examined. We report herein that Chimeric Polypeptide Doxorubicin (CP-Dox), a nanoparticle formulation of doxorubicin, enhances antitumor immunity. Compared to free doxorubicin, a single intravenous (IV) administration of CP-Dox at the maximum tolerated dose increases the infiltration of leukocytes into the tumor, slowing tumor growth and preventing metastasis in poorly immunogenic 4T1 mammary carcinoma. We demonstrate that the full efficacy of CP-Dox is dependent on CD8+ T cells and IFN-γ. CP-dox treatment also repolarized intratumoral myeloid cells towards an antitumor phenotype. These findings demonstrate that a nanoparticle drug is distinct from the free drug in its ability to productively stimulate antitumor immunity. Our study strongly argues for the use of antitumor immunotherapies combined with nanoparticle-packaged chemotherapy.
Model of CP-Dox's enhancement of the host antitumor immune response in 4T1 mammary carcinoma. CP-Dox treatment generates inflammatory chemokines and IFN-γ. Chemokine production leads to the recruitment of leukocytes including CD8+ T cells and inflammatory monocytes. CD8+ T cells, in the presence of increased IFN-γ, contribute to controlling the primary tumor and preventing metastasis. Display omitted
Pathologically swollen lymph nodes (LNs), or buboes, characterize Yersinia pestis infection, yet how they form and function is unknown. We report that colonization of the draining LN (dLN) occurred ...due to trafficking of infected dendritic cells and monocytes in temporally distinct waves in response to redundant chemotactic signals, including through CCR7, CCR2, and sphingosine-1-phospate (S1P) receptors. Retention of multiple subsets of phagocytes within peripheral LNs using the S1P receptor agonist FTY720 or S1P1-specific agonist SEW2871 increased survival, reduced colonization of downstream LNs, and limited progression to transmission-associated septicemic or pneumonic disease states. Conditional deletion of S1P1 in mononuclear phagocytes abolished node-to-node trafficking of infected cells. Thus, Y. pestis-orchestrated LN remodeling promoted its dissemination via host cells through the lymphatic system but can be blocked by prevention of leukocyte egress from DLNs. These findings define a novel trafficking route of mononuclear phagocytes and identify S1P as a therapeutic target during infection.
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•Y. pestis travel within DCs to lymph nodes, dependent on S1P, CCR7, and CCL21•Amplified cytokine production recruits additional monocytes and DCs, forming bubos•Infected cells traffic to higher-order LNs via lymphatics, dependent on S1P1•S1P agonists promote survival and limit septicemic and pneumonic plague
Yersinia pestis infection is characterized by pathologically swollen lymph nodes (LNs) but their relevance for disease progression is unclear. Abraham and colleagues show myeloid cells are recruited to infected LNs and Y. pestis exploits their trafficking through lymphatics to promote systemic bacterial spread.
Chlorine gas (Cl
) has been repeatedly used as a chemical weapon, first in World War I and most recently in Syria. Life-threatening Cl
exposures frequently occur in domestic and occupational ...environments, and in transportation accidents. Modeling the human etiology of Cl
-induced acute lung injury (ALI), forensic biomarkers, and targeted countermeasures development have been hampered by inadequate large animal models. The objective of this study was to develop a translational model of Cl
-induced ALI in swine to understand toxico-pathophysiology and evaluate whether it is suitable for screening potential medical countermeasures and to identify biomarkers useful for forensic analysis. Specific pathogen-free Yorkshire swine (30-40 kg) of either sex were exposed to Cl
(≤240 ppm for 1 h) or filtered air under anesthesia and controlled mechanical ventilation. Exposure to Cl
resulted in severe hypoxia and hypoxemia, increased airway resistance and peak inspiratory pressure, and decreased dynamic lung compliance. Cl
exposure resulted in increased total leucocyte and neutrophil counts in bronchoalveolar lavage fluid, vascular leakage, and pulmonary edema compared with the air-exposed group. The model recapitulated all three key histopathological features of human ALI, such as neutrophilic alveolitis, deposition of hyaline membranes, and formation of microthrombi. Free and lipid-bound 2-chlorofatty acids and chlorotyrosine-modified proteins (3-chloro-l-tyrosine and 3,5-dichloro-l-tyrosine) were detected in plasma and lung tissue after Cl
exposure. In this study, we developed a translational swine model that recapitulates key features of human Cl
inhalation injury and is suitable for testing medical countermeasures, and validated chlorinated fatty acids and protein adducts as biomarkers of Cl
inhalation.
We established a swine model of chlorine gas-induced acute lung injury that exhibits several features of human acute lung injury and is suitable for screening potential medical countermeasures. We validated chlorinated fatty acids and protein adducts in plasma and lung samples as forensic biomarkers of chlorine inhalation.
Introduction Environmental exposures and experimental manipulations can alter the ontogenetic composition of tissue-resident macrophages. However, the impact of these alterations on subsequent immune ...responses, particularly in allergic airway diseases, remains poorly understood. This study aims to elucidate the significance of modified macrophage ontogeny resulting from environmental exposures on allergic airway responses to house dust mite (HDM) allergen. Methods We utilized embryonic lineage labeling to delineate the ontogenetic profile of tissue-resident macrophages at baseline and following the resolution of repeated lipopolysaccharide (LPS)-induced lung injury. We investigated differences in house dust mite (HDM)-induced allergy to assess the influence of macrophage ontogeny on allergic airway responses. Additionally, we employed single-cell RNA sequencing (scRNAseq) and immunofluorescent staining to characterize the pulmonary macrophage composition, associated pathways, and tissue localization. Results Our findings demonstrate that the ontogeny of homeostatic alveolar and interstitial macrophages is altered after the resolution from repeated LPS-induced lung injury, leading to the replacement of embryonic-derived by bone marrow-derived macrophages. This shift in macrophage ontogeny is associated with reduced HDM-induced allergic airway responses. Through scRNAseq and immunofluorescent staining, we identified a distinct subset of resident-derived interstitial macrophages expressing genes associated with allergic airway diseases, localized adjacent to terminal bronchi, and diminished by prior LPS exposure. Discussion These results suggest a pivotal role for pulmonary macrophage ontogeny in modulating allergic airway responses. Moreover, our findings highlight the implications of prior environmental exposures in shaping future immune responses and influencing the development of allergies. By elucidating the mechanisms underlying these phenomena, this study provides valuable insights into potential therapeutic targets for allergic airway diseases and avenues for further research into immune modulation and allergic disease prevention.
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