scholarly journals Real-Time In Vivo Detection and Monitoring of Bacterial Infection Based on NIR-II Imaging

2021 ◽  
Vol 9 ◽  
Author(s):  
Sijia Feng ◽  
Huizhu Li ◽  
Chang Liu ◽  
Mo Chen ◽  
Huaixuan Sheng ◽  
...  
Keyword(s):  
Bacterial Infection ◽  
Real Time ◽  
Bacterial Infections ◽  
Near Infrared ◽  
Imaging System ◽  
Bacterial Load ◽  
Dynamic Imaging ◽  
In Vivo Detection

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.

scholarly journals Non-invasive, real-time reporting drug release in vitro and in vivo

2015 ◽  
Vol 51 (32) ◽  
pp. 6948-6951 ◽  
Author(s):  
Yanfeng Zhang ◽  
Qian Yin ◽  
Jonathan Yen ◽  
Joanne Li ◽  
Hanze Ying ◽  
...  
Keyword(s):  
Drug Release ◽  
Real Time ◽  
Near Infrared ◽  
Reporting System ◽  
Real Time Monitoring ◽  
Near Infrared Fluorescence ◽  
Non Invasive ◽  
Fluorescence Dye

Anin vitroandin vivodrug-reporting system is developed for real-time monitoring of drug release via the analysis of the concurrently released near-infrared fluorescence dye.

A colorimetric and near-infrared fluorescent turn-on probe for in vitro and in vivo detection of thiophenols

2015 ◽  
Vol 7 (18) ◽  
pp. 7534-7539 ◽  
Author(s):  
Dehuan Yu ◽  
Qisong Zhai ◽  
Shengjun Yang ◽  
Guoqiang Feng
Keyword(s):  
Rapid Detection ◽  
Near Infrared ◽  
Turn On ◽  
In Vivo Detection

A colorimetric and NIR fluorescent turn-on probe was reported for rapid detection of thiophenols.

The Innate Immune System Favors Emergency Monopoiesis at the Expense of DC Differentiation to Control Bacterial Infections

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2722-2722
Author(s):  
Kristin Bieber ◽  
Karina A. Pasquevich ◽  
Manina Günter ◽  
Matthias Grauer ◽  
Oliver Pötz ◽  
...  
Keyword(s):  
Immune System ◽  
Bacterial Infection ◽  
Bacterial Infections ◽  
Conflicts Of Interest ◽  
Bacterial Load ◽  
Innate Immune ◽  
General Response ◽  
The Impact ◽  
Myeloid Progenitors

Abstract Dendritic cells (DCs) are critical in host defense against infection, bridging the innate and adaptive immune system. Patients with sepsis display reduced circulating and splenic DCs and impaired DC function that may contribute to prolonged immune suppression and exacerbation of infection. However, the mechanisms of pathogen-induced DC depletion remain poorly understood. Here, a mouse model of systemic bacterial infection was employed to analyze the impact of different bacterial pathogens on DC development in vivo. We found that the numbers of bone marrow (BM) hematopoietic progenitors committed to the DC lineages were reduced following systemic infection with different Gram-positive and Gram-negative bacteria. In parallel, a TLR4-dependent increase of committed monocyte progenitors in the BM as well as mature monocytes in the spleen was observed. In line, adoptively transferred FLT3+ myeloid progenitors (MPs) developed preferentially to monocytes at the expense of DCs in infected animals. Analyses performed on mixed BM chimeras suggested that both the reduction of DC progenitors and the induction of monopoiesis following infection were dependent on extrinsic TLR4 signaling driving the secretion of IFN-g regulated chemokines. Consistently, these effects were completely abrogated by suppression of IFN-g signaling. Elevated monocyte numbers in the spleen triggered by infection were due to a CCR2-dependent egress from the BM. In CCR2-deficient mice, in which monocytosis reportedly is abrogated, we observed a significantly increased bacterial load in the spleen and a reduced survival rate, highlighting the importance of monocytes for bacterial clearance. Together, our data provide evidence for a general response of myeloid progenitors upon bacterial infection to enhance monocyte production, thereby increasing the availability of innate immune cells as a first line of defense against invading pathogens. Concomitantly the development of DCs is impaired, which may be responsible for transient immunosuppression in e.g. bacterial sepsis. Disclosures No relevant conflicts of interest to declare.

scholarly journals Real-Time Fluorescence Imaging Using Indocyanine Green to Assess Therapeutic Effects of Near-Infrared Photoimmunotherapy in Tumor Model Mice

2020 ◽  
Vol 19 ◽  
pp. 153601212093496
Author(s):  
Adrian Rosenberg ◽  
Daiki Fujimura ◽  
Ryuhei Okada ◽  
Aki Furusawa ◽  
Fuyuki Inagaki ◽  
...  
Keyword(s):  
Indocyanine Green ◽  
Real Time ◽  
Fluorescence Imaging ◽  
Near Infrared ◽  
Imaging System ◽  
Tumor Model ◽  
Therapeutic Effects ◽  
Tumor Perfusion ◽  
Background Ratio

Background: Near-infrared photoimmunotherapy (NIR-PIT) is a cancer therapy that causes an increase in tumor perfusion, a phenomenon termed the super-enhanced permeability and retention effect. Currently, in vivo treatment efficacy of NIR-PIT is observable days after treatment, but monitoring would be improved by more acute detection of intratumor change. Fluorescence imaging may detect increased tumor perfusion immediately after treatment. Methods: In the first experiment, athymic nude mouse models bearing unilateral subcutaneous flank tumors were treated with either NIR-PIT or laser therapy only. In the second experiment, mice bearing bilateral flank tumors were treated with NIR-PIT only on the left-sided tumor. In both groups, immediately after treatment, indocyanine green was injected at different doses intravenously, and mice were monitored with the Shimadzu LIGHTVISION fluorescence imaging system for 1 hour. Results: Tumor-to-background ratio of fluorescence intensity increased over the 60 minutes of monitoring in treated mice but did not vary significantly in control mice. Tumor-to-background ratio was highest in the 1 mg kg−1 and 0.3 mg kg−1 doses. In mice with bilateral tumors, tumor-to-untreated tumor ratio increased similarly. Conclusions: Acute changes in tumor perfusion after NIR-PIT can be detected by real-time fluorescence imaging.

Upconversion Luminescence Imaging of Tumors with EGFR-Affibody Conjugated Nanophosphors

MRS Advances ◽  
2019 ◽  
Vol 4 (46-47) ◽  
pp. 2461-2470 ◽  
Author(s):  
Majid Badieirostami ◽  
Colin Carpenter ◽  
Guillem Pratx ◽  
Lei Xing ◽  
Conroy Sun
Keyword(s):  
Near Infrared ◽  
Imaging System ◽  
Imaging Modality ◽  
Photophysical Properties ◽  
Upconversion Luminescence ◽  
Detection Sensitivity ◽  
Photon Absorption ◽  
Great Promise

ABSTRACTNear infrared (NIR) optical imaging has demonstrated significant potential as an effective modality for cancer molecular imaging. Among various NIR probes currently under investigation, upconversion nanophosphors (UCNPs) possess great promise due to their anti-Stokes emission and sequential photon absorption which result in superior detection sensitivity and a simple imaging setup, respectively. Here we investigated the utility of this imaging modality to detect tumor cells expressing the epidermal growth factor receptor (EGFR) using affibody functionalized nanophosphors and a custom built imaging system. Initially, aqueous dispersible NaYF4: Tm+3, Yb+3 UCNPs were synthesized and their photophysical properties were characterized. Then, their luminescence response as a function of concentration and their depth resolving capability in a tissue-simulating phantom were examined. Finally, we demonstrated the use of bioconjugated UCNPs for imaging EGFR-expressing tumors both in vitro and in vivo. Our data suggests that NIR imaging with UCNPs may be useful for noninvasive imaging of tumors.

scholarly journals Bacterial infection drives trained immunity through epigenetic remodeling of epithelial stem cells

2021 ◽  
Author(s):  
Scott Hultgren ◽  
Seongmi Russell ◽  
Hyung Joo Lee ◽  
Benjamin Olson ◽  
Jonathan Livny ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Death ◽  
Bacterial Infection ◽  
Bacterial Infections ◽  
Inflammatory Cell ◽  
Host Susceptibility ◽  
Epithelial Stem Cells ◽  
Caspase 1

Abstract Recurrent bacterial infections are a major health burden worldwide, yet the mechanisms dictating host susceptibility to recurrence are poorly understood. Here we demonstrate that an initial bacterial infection of the urinary bladder with uropathogenic E. coli (UPEC) can induce sustained epigenetic changes in the bladder epithelial (urothelial) stem cells that reprogram the differentiated urothelium. We established urothelial stem cell (USC) lines from isogenic mice with different urinary tract infection histories (naïve, chronic or self-resolving). Differentiation of the USC lines in Transwell culture resulted in polarized urothelial cultures that recapitulated distinct remodeling morphologies seen in vivo. In addition, we discovered differences in chromatin accessibility that segregated by disease history, resulting in differences in gene expression upon differentiation of the USC lines in vitro, based on ATAC-seq analysis of the USC lines. Differential basal expression of Caspase-1 led to divergent susceptibilities to inflammatory cell death upon UPEC infection. In mice with a history of chronic infection, enhanced caspase 1-mediated inflammatory cell death was found to be a protective response that enhanced bacterial clearance upon challenge infection. Thus, UPEC infection reshapes the epigenome leading to epithelial-intrinsic remodeling that trains the mucosal immune response to subsequent infection. These findings may have broad implications for the prevention of chronic/recurrent bacterial infections.

scholarly journals Contribution of Host Immune Responses Against Influenza D Virus Infection Toward Secondary Bacterial Infection in a Mouse Model

Viruses ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 994 ◽  
Author(s):  
Raegan M. Skelton ◽  
Kelly M. Shepardson ◽  
Alexis Hatton ◽  
Patrick T. Wilson ◽  
Chithra Sreenivasan ◽  
...  
Keyword(s):  
Immune Responses ◽  
Bacterial Infection ◽  
Bacterial Infections ◽  
Clinical Signs ◽  
A549 Cells ◽  
Host Susceptibility ◽  
Secondary Bacterial Infection ◽  
Aureus Infection

Influenza D viruses (IDV) are known to co-circulate with viral and bacterial pathogens in cattle and other ruminants. Currently, there is limited knowledge regarding host responses to IDV infection and whether IDV infection affects host susceptibility to secondary bacterial infections. To begin to address this gap in knowledge, the current study utilized a combination of in vivo and in vitro approaches to evaluate host cellular responses against primary IDV infection and secondary bacterial infection with Staphylococcus aureus (S. aureus). Primary IDV infection in mice did not result in clinical signs of disease and it did not enhance the susceptibility to secondary S. aureus infection. Rather, IDV infection appeared to protect mice from the usual clinical features of secondary bacterial infection, as demonstrated by improved weight loss, survival, and recovery when compared to S. aureus infection alone. We found a notable increase in IFN-β expression following IDV infection while utilizing human alveolar epithelial A549 cells to analyze early anti-viral responses to IDV infection. These results demonstrate for the first time that IDV infection does not increase the susceptibility to secondary bacterial infection with S. aureus, with evidence that anti-viral immune responses during IDV infection might protect the host against these potentially deadly outcomes.

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