Explore the vast range of titles available.

Summary The role of lymphatic vessels is to transport fluid, soluble molecules, and immune cells to the draining lymph nodes. Here, we analyze how the aging process affects the functionality of the lymphatic collectors and the dynamics of lymph flow. Ultrastructural, biochemical, and proteomic analysis indicates a loss of matrix proteins, and smooth muscle cells in aged collectors resulting in a decrease in contraction frequency, systolic lymph flow velocity, and pumping activity, as measured in vivo in lymphatic collectors. Functionally, this impairment also translated into a reduced ability for in vivo bacterial transport as determined by time-lapse microscopy. Ultrastructural and proteomic analysis also indicates a decrease in the thickness of the endothelial cell glycocalyx and loss of gap junction proteins in aged lymph collectors. Redox proteomic analysis mapped an aging-related increase in the glycation and carboxylation of lymphatic's endothelial cell and matrix proteins. Functionally, these modifications translate into apparent hyperpermeability of the lymphatics with pathogen escaping from the collectors into the surrounding tissue and a decreased ability to control tissue fluid homeostasis. Altogether, our data provide a mechanistic analysis of how the anatomical and biochemical changes, occurring in aged lymphatic vessels, compromise lymph flow, tissue fluid homeostasis, and pathogen transport.

Introduction Neoadjuvant endocrine therapy (NET) has demonstrated efficacy in post-menopausal patients with hormone-responsive breast cancer. This trial was designed to compare the efficacy of neoadjuvant chemotherapy (NCT) with NET in pre-menopausal breast cancer. Patients and methods In this prospective, randomised, phase III study, oestrogen receptor (ER)-positive, HER2-negative, and lymph node-positive pre-menopausal breast cancer patients were recruited from 7 hospitals in South Korea. Enrolled patients were randomly assigned (1:1) to receive 24 weeks of either NCT or NET with goserelin and tamoxifen. The primary purpose was to evaluate the non-inferiority of NET compared to NCT using clinical response, assessed by MRI. Besides, pathological complete response rate (pCR), changes in Ki-67 expression, breast conservation surgery (BCS) rate, and quality of life were included as secondary endpoints. Results A total of 187 patients were assigned to receive NCT ( n  = 95) or NET ( n  = 92), and 87 patients in each group completed treatments. More NCT patients had complete response or partial response than NET patients using MRI (NCT 83.7% vs. NET 52.9%, 95% CI 17.6–44.0, p  < 0.001) and callipers (NCT 83.9% vs. NET 71.3%, 95% CI 0.4–24.9, p  = 0.046). Three NCT patients (3.4%) and one NET patient (1.2%) showed pCR ( p  < 0.005). No difference existed in the conversion rate of BCS (13.8% for NCT vs. 11.5% for NET, p  = 0.531) and Ki-67 change ( p  = 0.114) between the two groups. Nineteen NCT patients had treatment-related grade 3 or worse events compared with none in the NET group. Conclusions Better clinical responses were observed in pre-menopausal patients after 24 weeks of NCT compared to those observed after NET. Trial registration Clinicaltrials.gov , NCT01622361 . Registration June 19, 2012.

Lymphocytes travel throughout the body to carry out immune surveillance and participate in inflammatory reactions. Their path takes them from blood through tissues into lymph and back to blood. Molecules that control lymphocyte recruitment into extralymphoid tissues are well characterized, but exit is assumed to be random. Here, we showed that lymphocyte emigration from the skin was regulated and was sensitive to pertussis toxin. CD4 + lymphocytes emigrated more efficiently than CD8 + or B lymphocytes. T lymphocytes in the afferent lymph expressed functional chemokine receptor CCR7, and CCR7 was required for T lymphocyte exit from the skin. The regulated expression of CCR7 by tissue T lymphocytes may control their exit, acting with recruitment mechanisms to regulate lymphocyte transit and accumulation during immune surveillance and inflammation.

T cell circulation between peripheral tissues and the lymphoid compartment is critical for immunosurveillance and host defense. However, the factors that determine whether T cells remain in peripheral tissue or return to the circulation are undefined. Here we demonstrate that the chemokine receptor CCR7 is a critical signal that determines T cell exit from peripheral tissue. Both CCR7 − and CCR7 + effector T cells entered mouse asthmatic lung and while CCR7 − T cells accumulated, CCR7 + T cells continued to migrate into afferent lymph. Delivery of both CCR7 + and CCR7 − T cells directly into the airways showed that only CCR7 + T cells exited the lung and entered draining lymph nodes. Our study establishes a molecular basis for T cell exit from peripheral tissues.

Lymph node and adipose tissue fibrosis may limit CD4+ T-cell recovery and contribute to comorbidities in treated human immunodeficiency virus (HIV) infection. We demonstrate that fibrosis decreases with continued suppressive antiretroviral therapy; telmisartan, an angiotensin receptor blocker and peroxisome proliferator-activated receptor γ agonist, confers no additional benefit. Abstract Background Fibrosis in lymph nodes may limit CD4+ T-cell recovery, and lymph node and adipose tissue fibrosis may contribute to inflammation and comorbidities despite antiretroviral therapy (ART). We hypothesized that the angiotensin receptor blocker and peroxisome proliferator-activated receptor γ agonist telmisartan would decrease lymph node or adipose tissue fibrosis in treated human immunodeficiency virus type 1 (HIV) infection. Methods In this 48-week, randomized, controlled trial, adults continued HIV–suppressive ART and received telmisartan or no drug. Collagen I, fibronectin, and phosphorylated SMAD3 (pSMAD3) deposition in lymph nodes, as well as collagen I, collagen VI, and fibronectin deposition in adipose tissue, were quantified by immunohistochemical analysis at weeks 0 and 48. Two-sided rank sum and signed rank tests compared changes over 48 weeks. Results Forty-four participants enrolled; 35 had paired adipose tissue specimens, and 29 had paired lymph node specimens. The median change overall in the percentage of the area throughout which collagen I was deposited was −2.6 percentage points (P = 0.08) in lymph node specimens and −1.3 percentage points (P = .001) in adipose tissue specimens, with no between-arm differences. In lymph node specimens, pSMAD3 deposition changed by −0.5 percentage points overall (P = .04), with no between-arm differences. Telmisartan attenuated increases in fibronectin deposition (P = .06). In adipose tissue, changes in collagen VI deposition (−1.0 percentage point; P = .001) and fibronectin deposition (−2.4 percentage points; P < .001) were observed, with no between-arm differences. Conclusions In adults with treated HIV infection, lymph node and adipose tissue fibrosis decreased with continued ART alone, with no additional fibrosis reduction with telmisartan therapy.

Global histone modification patterns correlate with tumor phenotypes and prognostic factors in multiple tumor types. Recent studies suggest that aberrant histone modifications play an important role in cancer. However, the effects of global epigenetic rearrangements on cell functions remain poorly understood. In this study, we show that the histone H3 lysine 9 (H3K9) methyltransferase SUV39H1 is clearly involved in regulating cell migration in vitro. Overexpression of wild‐type SUV39H1, but not enzymatically inactive SUV39H1, activated migration in breast and colorectal cancer cells. Inversely, migration was reduced by knockdown of SUV39H1 or chemical inhibition by chaetocin. In addition, H3K9 trimethylation (H3K9me3) was specifically increased in invasive regions of colorectal cancer tissues. Moreover, the presence of H3K9me3 positively correlated with lymph node metastasis in colorectal cancer patients. Furthermore, overexpression of SUV39H1 drove tumorigenesis in mouse, resulting in a considerable decrease in survival rate. These data indicate that H3K9 trimethylation plays an important role in human colorectal cancer progression, possibly by promoting collective cell invasion.

Cancer cells, including melanoma cells, often metastasize regionally through the lymphatic system before metastasizing systemically through the blood 1 , 2 , 3 – 4 ; however, the reason for this is unclear. Here we show that melanoma cells in lymph experience less oxidative stress and form more metastases than melanoma cells in blood. Immunocompromised mice with melanomas derived from patients, and immunocompetent mice with mouse melanomas, had more melanoma cells per microlitre in tumour-draining lymph than in tumour-draining blood. Cells that metastasized through blood, but not those that metastasized through lymph, became dependent on the ferroptosis inhibitor GPX4. Cells that were pretreated with chemical ferroptosis inhibitors formed more metastases than untreated cells after intravenous, but not intralymphatic, injection. We observed multiple differences between lymph fluid and blood plasma that may contribute to decreased oxidative stress and ferroptosis in lymph, including higher levels of glutathione and oleic acid and less free iron in lymph. Oleic acid protected melanoma cells from ferroptosis in an Acsl3 -dependent manner and increased their capacity to form metastatic tumours. Melanoma cells from lymph nodes were more resistant to ferroptosis and formed more metastases after intravenous injection than did melanoma cells from subcutaneous tumours. Exposure to the lymphatic environment thus protects melanoma cells from ferroptosis and increases their ability to survive during subsequent metastasis through the blood. Melanoma cells undergo less oxidative stress and less ferroptosis in lymph than in blood, owing to higher levels of oleic acid in lymph, and thus exposure to the lymphatic environment increases subsequent metastasis through blood.

Extrapulmonary manifestations constitute 15 to 20% of tuberculosis cases, with lymph node tuberculosis (LNTB) as the most common form of infection. However, diagnosis and treatment advances are hindered by lack of understanding of LNTB biology. To identify host response, Mycobacterium tuberculosis infected lymph nodes from LNTB patients were studied by means of transcriptomics and quantitative proteomics analyses. The selected targets obtained by comparative analyses were validated by quantitative PCR and immunohistochemistry. This approach provided expression data for 8,728 transcripts and 102 proteins, differentially regulated in the infected human lymph node. Enhanced inflammation with upregulation of T-helper1-related genes, combined with marked dysregulation of matrix metalloproteinases, indicates tissue damage due to high immunoactivity at infected niche. This expression signature was accompanied by significant upregulation of an immunoregulatory gene, leukotriene A4 hydrolase, at both transcript and protein levels. Comparative transcriptional analyses revealed LNTB-specific perturbations. In contrast to pulmonary TB-associated increase in lipid metabolism, genes involved in fatty-acid metabolism were found to be downregulated in LNTB suggesting differential lipid metabolic signature. This study investigates the tissue molecular signature of LNTB patients for the first time and presents findings that indicate the possible mechanism of disease pathology through dysregulation of inflammatory and tissue-repair processes.

A large number of gamma delta T cells (γδ T cells) are located within epithelial tissues including the skin. In mice, epidermal and dermal γδ T cells consist of distinct subsets and have specific roles in cutaneous immune responses. A recent study demonstrated that γδ T cells and cutaneous dendritic cells migrate from the skin to the draining lymph nodes (LNs). However, it remains unclear whether they regulate the antigen-specific immune response within the LNs. Herein, we investigated their properties and role in the LNs using the Mycobacterium bovis bacille Calmette–Guérin (BCG) infection model. In vivo cell labeling analysis revealed that most of the migratory subset comprised dermal Vγ4+ cells. This population transmigrated from the skin to the LNs in a Gi-coupled chemokine receptor–independent manner. By depleting Vγ4+ cells, the intranodal expansion of CD8+ T cell against BCG was significantly attenuated. In addition, in vitro analysis revealed that Vγ4+ cells produced TNF-α and enhanced IL-12 production by dendritic cells. Taken together, these findings suggest that dermal Vγ4+ cells are a unique subset that possesses a migratory potency to the skin-draining LNs and enhances the dendritic cell function therein.

Leishmania major parasites reside and multiply in late endosomal compartments of host phagocytic cells. Immune control of Leishmania growth absolutely requires expression of inducible Nitric Oxide Synthase (iNOS/NOS2) and subsequent production of NO. Here, we show that CD11b+ CD11c+ Ly-6C+ MHC-II+ cells are the main iNOS-producing cells in the footpad lesion and in the draining lymph node of Leishmania major-infected C57BL/6 mice. These cells are phenotypically similar to iNOS-producing inflammatory DC (iNOS-DC) observed in the mouse models of Listeria monocytogenes and Brucella melitensis infection. The use of DsRed-expressing parasites demonstrated that these iNOS-producing cells are the major infected population in the lesions and the draining lymph nodes. Analysis of various genetically deficient mouse strains revealed the requirement of CCR2 expression for the recruitment of iNOS-DC in the draining lymph nodes, whereas their activation is strongly dependent on CD40, IL-12, IFN-gamma and MyD88 molecules with a partial contribution of TNF-alpha and TLR9. In contrast, STAT-6 deficiency enhanced iNOS-DC recruitment and activation in susceptible BALB/c mice, demonstrating a key role for IL-4 and IL-13 as negative regulators. Taken together, our results suggest that iNOS-DC represent a major class of Th1-regulated effector cell population and constitute the most frequent infected cell type during chronic Leishmania major infection phase of C57BL/6 resistant mice.