scholarly journals Spike protein multiorgan tropism suppressed by antibodies targeting SARS-CoV-2

2021 ◽  
Author(s):  
Molly Brady ◽  
Abigail Combs ◽  
Chethana Venkatraman ◽  
Alexander Solorzano ◽  
Angelique Johnson ◽  
...  

While there is clinical evidence of severe acute respiratory syndrome coronavirus 2 multiorgan tropism in severely infected coronavirus 19 patients, it is unclear if there is differential multiorgan biodistribution and organ uptake in healthy young individuals, a group that usually has asymptomatic to moderate coronavirus 19 symptoms. In addition, for antibody therapies and vaccines that target the spike protein, it is unclear if these reduce severe acute respiratory syndrome coronavirus 2 or spike protein multiorgan tropism equally. We used fluorescently labeled spike protein near infrared fluorescence to study viral behavior, using an in vivo dynamic imaging system, in young mice. We found a spike protein body-wide biodistribution followed by a slow regional elimination, except for the liver, which showed an accumulation. Spike protein uptake was highest for the lungs, and this was followed by kidney, heart and liver, but, unlike the choroid plexus, it was not detected in the brain parenchyma or cerebrospinal fluid. Thus, the brain vascular barriers were effective in restricting the entry of spike protein into brain parenchyma in young healthy mice. While both anti-angiotensin converting enzyme 2 and anti-spike protein antibodies suppressed spike protein biodistribution and organ uptake, anti-spike protein antibody was more effective. By extension, our data support the efficacy of these antibodies on severe acute respiratory syndrome coronavirus 2 biodistribution kinetics and multiorgan tropism that could determine coronavirus 19 organ-specific outcomes.

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Molly Brady ◽  
Conor McQuaid ◽  
Alexander Solorzano ◽  
Angelique Johnson ◽  
Abigail Combs ◽  
...  

AbstractWhile there is SARS-CoV-2 multiorgan tropism in severely infected COVID-19 patients, it’s unclear if this occurs in healthy young individuals. In addition, for antibodies that target the spike protein (SP), it’s unclear if these reduce SARS-CoV-2/SP multiorgan tropism equally. We used fluorescently labeled SP-NIRF to study viral behavior, using an in vivo dynamic imaging system and ex in vivo tissue analysis, in young mice. We found a SP body-wide biodistribution followed by a slow regional elimination, except for the liver, which showed an accumulation. SP uptake was highest for the lungs, and this was followed by kidney, heart and liver, but, unlike the choroid plexus, it was not detected in the brain parenchyma or CSF. Thus, the brain vascular barriers were effective in restricting the entry of SP into brain parenchyma in young healthy mice. While both anti-ACE2 and anti-SP antibodies suppressed SP biodistribution and organ uptake, anti-SP antibody was more effective. By extension, our data support the efficacy of these antibodies on SARS-CoV-2 multiorgan tropism, which could determine COVID-19 organ-specific outcomes.


2021 ◽  
Vol 9 ◽  
Author(s):  
Sijia Feng ◽  
Huizhu Li ◽  
Chang Liu ◽  
Mo Chen ◽  
Huaixuan Sheng ◽  
...  

Treatment according to the dynamic changes of bacterial load in vivo is critical for preventing progression of bacterial infections. Here, we present a lead sulfide quantum dots (PbS QDs) based second near-infrared (NIR-II) fluorescence imaging strategy for bacteria detection and real-time in vivo monitoring. Four strains of bacteria were labeled with synthesized PbS QDs which showed high bacteria labeling efficiency in vitro. Then bacteria at different concentrations were injected subcutaneously on the back of male nude mice for in vivo imaging. A series of NIR-II images taken at a predetermined time manner demonstrated changing patterns of photoluminescence (PL) intensity of infected sites, dynamically imaging a changing bacterial load in real-time. A detection limit around 102–104 CFU/ml was also achieved in vivo. Furthermore, analysis of pathology of infected sites were performed, which showed high biocompatibility of PbS QDs. Therefore, under the guidance of our developed NIR-II imaging system, real-time detection and spatiotemporal monitoring of bacterial infection in vivo can be achieved, thus facilitating anti-infection treatment under the guidance of the dynamic imaging of bacterial load in future.


2011 ◽  
Vol 04 (02) ◽  
pp. 199-208
Author(s):  
ZHIQIU LI ◽  
SHUDONG JIANG ◽  
VENKATARAMANAN KRISHNASWAMY ◽  
SCOTT C. DAVIS ◽  
SUBHADRA SRINIVASAN ◽  
...  

A near-infrared (NIR) tomography system with spectrally-encoded sources in two wavelength bands was built to quantify the temporal oxyhemoglobin and deoxyhemoglobin contrast in breast tissue at a 20 Hz bandwidth. The system was integrated into a 3 T magnetic resonance (MR) imaging system through a customized breast coil interface for simultaneous optical and MRI acquisition. In this configuration, the MR images provide breast tissue structural information for NIR spectroscopy of adipose and fibro-glandular tissue in breast. Spectral characterization performance of the NIR system was verified through dynamic phantom experiments. Normal human subjects were imaged with finger pulse oximeter (PO) plethysmogram synchronized to the NIR system to provide a frequency-locked reference. Both the raw data from the NIR system and the recovered absorption coefficients of the breast at two wavelengths showed the same frequency of about 1.3 Hz as the PO output. The frequency lock-in approach provided a practical platform for MR-localized recovery of small pulsatile variations of oxyhemoglobin and deoxyhemoglobin in the breast, which are related to the heartbeat and vascular resistance of the tissue.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii110-ii111
Author(s):  
Kira Downey ◽  
Bindu Hegde ◽  
Zinal Chheda ◽  
Jason Zhang ◽  
Hideho Okada

Abstract The lack of conventional lymphatic drainage to and from the brain parenchyma restricts the capacity of the peripheral immune system to recognize and respond to glioma antigens. In some peripheral solid tumor types and central nervous system autoimmunity, the spontaneous development of tertiary lymphoid structures (TLS) with varying degrees of organization have been observed in human patients and mice following chronic inflammation. In the cancer setting, presence of TLS are generally associated with improved prognosis, especially when they are characterized by intratumoral infiltration of CD8+ T-cells. We aimed to induce the development of TLS in vivo, utilizing our SB28 glioblastoma model which is sparsely infiltrated by lymphocytes. As a proof-of-concept study, we stably transduced SB28 with a combination of several TLS-stimulating factors that we’ve identified and injected these cells into the brain parenchyma of syngeneic C57BL/6J mice. A combination of the chemoattractant and lymphoid follicle-stimulating cytokines LIGHT, CCL21, IL-7, and IL-17 produced substantial infiltration of CD8+CD3+ T-cells into the tumor and nearby parenchyma. However, this combination was also associated with accelerated tumor growth. A modified gene combination including LIGHT, CCL21, and IL-7 promoted CD8+CD3+ T-cell infiltration by flow cytometry, T-cell clustering by immunofluorescence analysis, and inhibited tumor burden compared with the control as measured by bioluminescent imaging. There was also evidence of increased lymphatic vasculature around the margins of T-cell clustering as demonstrated by LYVE-1 staining. Together, these analyses highlight a role for these factors in stimulating the recruitment and clustering of T-cell to the glioblastoma microenvironment in a TLS-like phenomenon. Future studies will evaluate whether the recruitment of other lymphocytes and stromal cells to these TLS-like clusters can promote T-cell memory and persistence. Ultimately, we aim to provide these factors utilizing a gene delivery method that will prove translatable to the clinic and complementary to existing T-cell therapies.


Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1833
Author(s):  
Shannon Morgan McCabe ◽  
Ningning Zhao

Manganese (Mn) is a trace nutrient necessary for life but becomes neurotoxic at high concentrations in the brain. The brain is a “privileged” organ that is separated from systemic blood circulation mainly by two barriers. Endothelial cells within the brain form tight junctions and act as the blood–brain barrier (BBB), which physically separates circulating blood from the brain parenchyma. Between the blood and the cerebrospinal fluid (CSF) is the choroid plexus (CP), which is a tissue that acts as the blood–CSF barrier (BCB). Pharmaceuticals, proteins, and metals in the systemic circulation are unable to reach the brain and spinal cord unless transported through either of the two brain barriers. The BBB and the BCB consist of tightly connected cells that fulfill the critical role of neuroprotection and control the exchange of materials between the brain environment and blood circulation. Many recent publications provide insights into Mn transport in vivo or in cell models. In this review, we will focus on the current research regarding Mn metabolism in the brain and discuss the potential roles of the BBB and BCB in maintaining brain Mn homeostasis.


Author(s):  
Taïssia Lelekov-Boissard ◽  
Guillemette Chapuisat ◽  
Jean-Pierre Boissel ◽  
Emmanuel Grenier ◽  
Marie-Aimée Dronne

The inflammatory process during stroke consists of activation of resident brain microglia and recruitment of leucocytes, namely neutrophils and monocytes/macrophages. During inflammation, microglial cells, neutrophils and macrophages secrete inflammatory cytokines and chemokines, and phagocytize dead cells. The recruitment of blood cells (neutrophils and macrophages) is mediated by the leucocyte–endothelium interactions and more specifically by cell adhesion molecules. A mathematical model is proposed to represent the dynamics of various brain cells and of immune cells (neutrophils and macrophages). This model is based on a set of six ordinary differential equations and explores the beneficial and deleterious effects of inflammation, respectively phagocytosis by immune cells and the release of pro-inflammatory mediators and nitric oxide (NO). The results of our simulations are qualitatively consistent with those observed in experiments in vivo and would suggest that the increase of phagocytosis could contribute to the increase of the percentage of living cells. The inhibition of the production of cytokines and NO and the blocking of neutrophil and macrophage infiltration into the brain parenchyma led also to the improvement of brain cell survival. This approach may help to explore the respective contributions of the beneficial and deleterious roles of the inflammatory process in stroke, and to study various therapeutic strategies in order to reduce stroke damage.


2019 ◽  
Vol 20 (10) ◽  
pp. 2435 ◽  
Author(s):  
Tetsuya Takahashi ◽  
Takayoshi Shimohata

Methylmercury (MeHg) causes severe damage to the central nervous system, and there is increasing evidence of the association between MeHg exposure and vascular dysfunction, hemorrhage, and edema in the brain, but not in other organs of patients with acute MeHg intoxication. These observations suggest that MeHg possibly causes blood–brain barrier (BBB) damage. MeHg penetrates the BBB into the brain parenchyma via active transport systems, mainly the l-type amino acid transporter 1, on endothelial cell membranes. Recently, exposure to mercury has significantly increased. Numerous reports suggest that long-term low-level MeHg exposure can impair endothelial function and increase the risks of cardiovascular disease. The most widely reported mechanism of MeHg toxicity is oxidative stress and related pathways, such as neuroinflammation. BBB dysfunction has been suggested by both in vitro and in vivo models of MeHg intoxication. Therapy targeted at both maintaining the BBB and suppressing oxidative stress may represent a promising therapeutic strategy for MeHg intoxication. This paper reviews studies on the relationship between MeHg exposure and vascular dysfunction, with a special emphasis on the BBB.


2019 ◽  
Author(s):  
Felix C. Nebeling ◽  
Stefanie Poll ◽  
Lena C. Schmid ◽  
Manuel Mittag ◽  
Julia Steffen ◽  
...  

AbstractMicroglia, the resident immune cells of the brain, play a complex role in health and disease. They actively survey the brain parenchyma by physically interacting with other cells and structurally shaping the brain. Yet, the mechanisms underlying microglia motility and their significance for synapse stability, especially during adulthood, remain widely unresolved. Here we investigated the impact of neuronal activity on microglia motility and its implication for synapse formation and survival. We used repetitive two-photon in vivo imaging in the hippocampus of awake mice to simultaneously study microglia motility and their interaction with synapses. We found that microglia process motility depended on neuronal activity. Simultaneously, more dendritic spines emerged in awake compared to anesthetized mice. Interestingly, microglia contact rates with individual dendritic spines were associated with their stability. These results suggest that microglia are not only sensing neuronal activity, but participate in synaptic rewiring of the hippocampus during adulthood, which has profound relevance for learning and memory processes.


2020 ◽  
Vol 21 (8) ◽  
Author(s):  
Prakash Ramalingam ◽  
Palanivel Ganesan ◽  
D. S. Prabakaran ◽  
Pardeep K. Gupta ◽  
Sriramakamal Jonnalagadda ◽  
...  

2002 ◽  
Vol 227 (8) ◽  
pp. 609-615 ◽  
Author(s):  
Weihong Pan ◽  
Beka Solomon ◽  
Lawrence M. Maness ◽  
Abba J. Kastin

Amyloid-β peptides (Aβ) play an important role in the pathophysiology of dementia of the Alzheimer's type and in amyloid angiopathy. Aβ outside the CNS could contribute to plaque formation in the brain where its entry would involve interactions with the blood-brain barrier (BBB). Effective antibodies to Aβ have been developed in an effort to vaccinate against Alzheimer's disease. These antibodies could interact with Aβ in the peripheral blood, block the passage of Aβ across the BBB, or prevent Aβ deposition within the CNS. To determine whether the blocking antibodies act at the BBB level, we examined the influx of radiolabeled Aβ (125I-Aβ1-40) into the brain after ex-vivo incubation with the antibodies. Antibody mAb3D6 (élan Company) reduced the blood-to-brain influx of Aβ after iv bolus injection. It also significantly decreased the accumulation of Aβ in brain parenchyma. To confirm the in-vivo study and examine the specificity of mAb3D6, in-situ brain perfusion in serum-free buffer was performed after incubation of 125I-Aβ1-40 with another antibody mAbmc1 (DAKO Company). The presence of mAbmc1 also caused significant reduction of the influx of Aβ into the brain after perfusion. Therefore, effective antibodies to Aβ can reduce the influx of Aβ1-40 into the brain.


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