In Vivo Imaging of Lymphatic Vessels and Lymph Nodes

Abstract Abstract SCI-51 Lymph nodes provide specialized stromal environments that support the maintenance and homeostasis of T and B lymphocyte populations and are also staging grounds for lymphocyte effector responses against pathogens and transformed cells. They serve as immune information hotspots by collecting lymph fluid from peripheral tissues, especially our external and internal epithelial body surfaces, thus displaying a condensed representation of foreign and self-antigens at these sites in addition to integrating innate alarm signals that report tissue damage or pathogen invasion. Naïve B and T cells constantly traffic through these environments via the blood stream and efferent lymphatic vessels, which allows for efficient matching of their antigen receptor repertoires with the regional antigenic landscape. Depending on the absence or presence of signs of a potential threat to the organism, the result may be either tolerance or immunity towards the origin of these antigens. The architecture of lymph nodes is optimized to facilitate the presentation of lymph-borne antigen in various forms and to guide naïve lymphocytes in their search for 'their' cognate antigen in the form in which they are able to 'see' it. It also facilitates the cellular crosstalk with other immune cell populations that shape and regulate an ensuing adaptive response if cognate antigen is encountered in an immunogenic context. Our conception of how these various tasks are accomplished has recently been enriched through new methodological approaches that include the dynamic in situ or in vivo visualization of cellular and molecular processes using modern microscopy technology. We will review some recent insights into the function of lymph nodes derived from these studies. Disclosures No relevant conflicts of interest to declare.

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Neutrophils rapidly migrate via lymphatics after Mycobacterium bovis BCG intradermal vaccination and shuttle live bacilli to the draining lymph nodes

Blood ◽

10.1182/blood-2005-03-1281 ◽

2005 ◽

Vol 106 (5) ◽

pp. 1843-1850 ◽

Cited By ~ 223

Author(s):

Valérie Abadie ◽

Edgar Badell ◽

Patrice Douillard ◽

Danielle Ensergueix ◽

Pieter J. M. Leenen ◽

...

Keyword(s):

Lymph Nodes ◽

Mycobacterium Bovis ◽

Lymphatic Vessels ◽

Lymphoid Organ ◽

Host Cells ◽

Intradermal Vaccination ◽

Bcg Vaccination ◽

Inflammatory Monocytes ◽

Draining Lymph Nodes

Abstract The early innate response after Mycobacterium bovis bacille Calmette-Guérin (BCG) vaccination is poorly characterized but probably decisive for subsequent protective immunity against tuberculosis. Therefore, we vaccinated mice with fluorescent BCG strains in the ear dorsum, as a surrogate of intradermal vaccination in humans. During the first 3 days, we tracked BCG host cells migrating out of the dermis to the auricular draining lymph nodes (ADLNs). Resident skin dendritic cells (DCs) or macrophages did not play a predominant role in early BCG capture and transport to ADLNs. The main BCG host cells rapidly recruited both in the dermis and ADLNs were neutrophils. Fluorescent green or red BCG strains injected into nonoverlapping sites were essentially sheltered by distinct neutrophils in the ADLN capsule, indicating that neutrophils had captured bacilli in peripheral tissue and transported them to the lymphoid organ. Strikingly, we observed BCG-infected neutrophils in the lumen of lymphatic vessels by confocal microscopy on ear dermis. Fluorescence-labeled neutrophils injected into the ears accumulated exclusively into the ipsilateral ADLN capsule after BCG vaccination. Thus, we provide in vivo evidence that neutrophils, like DCs or inflammatory monocytes, migrate via afferent lymphatics to lymphoid tissue and can shuttle live microorganisms. (Blood. 2005;106: 1843-1850)

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Ex vivo Demonstration of Functional Deficiencies in Popliteal Lymphatic Vessels from TNF-Tg Mice with Inflammatory Arthritis

10.1101/2020.09.22.309070 ◽

2020 ◽

Author(s):

Joshua P. Scallan ◽

Echoe M. Bouta ◽

Homaira Rahimi ◽

H. Mark Kenney ◽

Christopher T. Ritchlin ◽

...

Keyword(s):

Lymph Nodes ◽

Repeated Measures ◽

Inflammatory Arthritis ◽

Ex Vivo ◽

Lymphatic Vessels ◽

Chronic Inflammatory Arthritis ◽

Wide Range ◽

Nos Inhibitors ◽

Draining Lymph Nodes

AbstractBackgroundRheumatoid arthritis (RA) is a progressive immune-mediated inflammatory disease characterized by intermittent episodes of pain and inflammation in affected joints, or flares. Recent studies demonstrated lymphangiogenesis and expansion of draining lymph nodes during chronic inflammatory arthritis, and lymphatic dysfunction associated with collapse of draining lymph nodes in RA patients and TNF-transgenic (TNF-Tg) mice experiencing arthritic flare. As the intrinsic differences between lymphatic vessels afferent to healthy, expanding, and collapsed draining lymph nodes are unknown, we characterized the ex vivo behavior of popliteal lymphatic vessels (PLVs) from WT and TNF-Tg mice. We also interrogated the mechanisms of lymphatic dysfunction through inhibition of nitric oxide synthase (NOS).MethodsPopliteal lymph nodes (PLNs) in TNF-Tg mice were phenotyped as Expanding or Collapsed by in vivo ultrasound and age-matched to WT littermate controls. The PLVs were harvested and cannulated for ex vivo functional analysis over a relatively wide range of hydrostatic pressures (0.5 to 10 cmH2O) to quantify the end diastolic diameter (EDD), tone, amplitude (AMP), ejection fraction (EF), contraction frequency (FREQ) and fractional pump flow (FPF) with or without NOS inhibitors Data was analyzed using repeated measures two-way ANOVA with Bonferroni’s post hoc test.ResultsReal time videos of the cannulated PLVs demonstrated the predicted phenotypes of robust versus weak contractions of the WT versus TNF-Tg PLV, respectively. Quantitative analyses confirmed that TNF-Tg PLVs had significantly decreased AMP, EF and FPF versus WT (p<0.05). EF and FPF were recovered by NOS inhibition, while the reduction in AMP was NOS independent. No differences in EDD, tone, or FREQ were observed between WT and TNF-Tg PLVs, nor between Expanding versus Collapsed PLVs.ConclusionThese findings support the concept that chronic inflammatory arthritis leads to NOS dependent and independent draining lymphatic vessel dysfunction that exacerbates disease, and may trigger arthritic flare due to decreased egress of inflammatory cells and soluble factors from affected joints.

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Regional Lymph Nodes Distribution Pattern in Central Area of Right-sided Colon Cancer: In-Vivo Detection and the Update on the Clinical Exploration.

10.21203/rs.3.rs-95107/v1 ◽

2020 ◽

Author(s):

Xiaochuang Feng ◽

Hongming Li ◽

Xinquan Lu ◽

Xiaojiang Yi ◽

Jin Wan ◽

...

Keyword(s):

Colon Cancer ◽

Lymph Nodes ◽

Distribution Pattern ◽

Lymphatic Vessels ◽

Central Area ◽

Radical Resection ◽

Pathology Report ◽

Target Area ◽

Regional Lymph Nodes

Abstract BackgroundDistribution of regional lymph nodes (LNs) is decisive for the lymphadenectomy boundary in radical resection of a right-sided colon cancer (RCC). Currently, the data of LNs in central area remains ambiguous and scarce. Herein we aim to provide a more detailed anatomical research on LNs surrounding the superior mesenteric vessels for RCC and investigated the metastasis rate.MethodsCarbon Nanoparticles (CNs) or Indocyanine Green (ICG) were used as dye and we laparoscopically observed the stained LNs distribution pattern and analyzed the harvested LNs combined with pathology report. Lastly, 137 RCC patients who received a “superior mesenteric artery (SMA)-oriented” hemicolectomy from September 2016 to September 2020 were included to calculate the probability of LNs metastasis in our target area.Results20 patients diagnosed as RCC (mean age 55.55 years, 13 male) were included. 13 patients underwent CNs injection and 7 patients consented to the ICG, while 4 cases suffered from imaging failure. The unequal number of the regional LNs located between SMV and SMA was detected in 17 cases (85%), posterior to SMV area in 6 cases (30%), and anterior to SMA in 11 cases (55%), respectively. The presence of LNs posterior to SMV was associated with the crossing pattern of ileocolic artery (²= 5.38, p= 0.020). The probability of LNs metastasis in the above areas (target areas) was 2.19% (3/137). No dyed LNs occurred when the SMA sheath was exposed. What’s more, the number of total harvested LNs in patients with dye injection was significant more than dye-free RCC patients (22.44±13.78 vs 43.20±22.70, p<0.01). ConclusionRight-hemi colon-draining lymphatic vessels anteriorly/posteriorly traversed the SMV and arrived at the surface of SMA near the middle colonic artery (MCA) level, which highlights the potential need of CME to place the internal border anterior to SMA and the removal of mesenteric tissue in our target area on lymphatic resection.

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