scholarly journals NOD2 dependent neutrophil recruitment is required for early protective immune responses against infectious Litomosoides sigmodontis L3 larvae

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Jesuthas Ajendra ◽  
Sabine Specht ◽  
Sebastian Ziewer ◽  
Andrea Schiefer ◽  
Kenneth Pfarr ◽  
...  
Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. SCI-24-SCI-24
Author(s):  
Mark J. Miller

Abstract Cell-mediated immune responses are highly dependent on environmental context, thus making in vivo studies an important complement to in vitro and molecular approaches. Two-photon microscopy (2PM) is a fluorescence based imaging approach that allows single-cell dynamics to be studied directly in their 3D native tissue context. 2PM is an ideal approach for analyzing leukocyte trafficking dynamics quantitatively and testing cellular immune mechanisms in vivo. Several example applications will be presented where 2PM has uncovered novel immunological phenomena and provided fresh insight into immune responses to infection, autoimmunity and cancer. While 2P imaging has been used extensively to study immune cell trafficking and function in mice, progress is being made to use this imaging technique on clinical biopsy specimens to acquire a multi-dimensional picture of human tissue pathology. We used in vivo 2PM in pre-clinical models of arthritis and bacterial infection to compare and contrast the role of monocytes on neutrophil recruitment. The rapid recruitment of neutrophils and monocytes is critical to early host immune responses to bacterial infection. However, leukocyte recruitment also contributes to chronic inflammatory diseases such as human rheumatoid arthritis. Understanding how cell recruitment is regulated in different inflammatory contexts is crucial for developing safe and effective anti-inflammatory therapies. We found that monocyte depletion with clodronate-liposomes prevented arthritis development in a modified K/BxN serum transfer arthritis model. This protective effect was associated with significantly reduced neutrophil transendothelial migration efficiency. Furthermore, single-cell tracking of a minor population of extravasated neutrophils showed that neutrophil migration and chemotaxis in interstitial tissues was disrupted, contributing to decreased cell localization at phalangeal joints. Similar results were obtained when CCR2+ monocytes were depleted selectively using the monoclonal antibody MC-21, thus implicating CCR2+ monocytes as key regulators of neutrophil extravasation during arthritis initiation. In contrast, neutrophil recruitment to subcutaneous bacterial challenge remained intact and neutrophil extravasation and chemotaxis to sites of infection was not significantly different as compared to non-depleted controls. We also examined whether neutrophil extravasation during acute pulmonary inflammation required monocytes. Neutrophil recruitment in vivo was assessed in a mouse lung transplant-mediated ischemia reperfusion injury model. Similar to the results in the arthritis model, neutrophil recruitment in response to ischemia reperfusion injury was also monocyte dependent. In addition, Ccr2 knockout recipient mice were protected for ischemia reperfusion injury. Results from these complementary mouse models implicate CCR2+ monocytes as key regulators of neutrophil extravasation and chemotaxis in under conditions of aseptic inflammation and further suggest that the cell recruitment signals that that operate during bacterial infection may be quantitatively and/or qualitatively distinct. These studies raise the intriguing possibility that targeting monocytes during chronic inflammatory diseases such as rheumatoid arthritis or acute inflammatory conditions such as ischemia reperfusion injury might provide safer and more selective anti-inflammatory therapies than those that target neutrophils directly. Disclosures: No relevant conflicts of interest to declare.


Parasitology ◽  
2000 ◽  
Vol 120 (3) ◽  
pp. 271-280 ◽  
Author(s):  
L. LE GOFF ◽  
C. MARTIN ◽  
I. P. OSWALD ◽  
P. N. VUONG ◽  
G. PETIT ◽  
...  

This study was performed with Litomosoides sigmodontis, the only filarial species which can develop from the infective larvae to the patent phase in immunocompetent laboratory BALB/c mice. Parasitological features and immune responses were analysed up to 3 months before and after challenge inoculation, by comparing 4 groups of mice: vaccinated challenged, challenged only, vaccinated only, and naive mice. Male larvae were very susceptible to irradiation and only female irradiated larvae survived in vivo. Protection, assessed by a lower recovery rate, was confirmed and was established within the first 2 days of challenge. This early reduction of the recovery rate in vaccinated challenged mice was determined by their immune status prior to the challenge inoculation. This was characterized by high specific IgM and IgG subclass (IgG1, IgG2a and IgG3) levels, high specific IL-5 secretion from spleen cells in vitro and a high density of eosinophils in the subcutaneous connective tissue. Six h after the challenge inoculation, most tissue eosinophils were degranulated in vaccinated challenged mice. Thus, in the protocol of vaccination described, protection appeared mainly to result from the stimulation of a Th2 type response and eosinophils seemed to be the main effectors for the increased killing of infective larvae in vaccinated challenged mice. Two months after challenge inoculation, the percentage of microfilaraemic mice was lower in vaccinated challenged mice as a consequence of this overall reduction in the worm load. In both vaccinated challenged and challenged only groups, the in vitro splenocyte proliferative capacity was reduced in microfilaraemic mice.


2020 ◽  
Vol 14 (2) ◽  
pp. e0008119 ◽  
Author(s):  
Stefan J. Frohberger ◽  
Frederic Fercoq ◽  
Anna-Lena Neumann ◽  
Jayagopi Surendar ◽  
Wiebke Stamminger ◽  
...  

2003 ◽  
Vol 71 (12) ◽  
pp. 6820-6829 ◽  
Author(s):  
Simon Babayan ◽  
Marie-Noëlle Ungeheuer ◽  
Coralie Martin ◽  
Tarik Attout ◽  
Elodie Belnoue ◽  
...  

ABSTRACT In order to understand natural resistance to filariasis, we compared Litomosoides sigmodontis primary infection of C57BL/6 mice, which eliminate the worms before patency, and BALB/c mice, in which worms complete their development and produce microfilariae. Our analysis over the first month of infection monitoredmigration of the infective larvae from the lymph nodes to the pleural cavity, where the worms settle. Although immune responses from the mouse strains differed from the outset, the duration of lymphatic migration (4 days) and filarial recovery rates were similar, thus confirming that the proportion of larvae that develop in the host species upon infection is not influenced by host genetic variability. The majority of worms reached the adult stage in both mouse strains; however, worm growth and molting were retarded in resistant C57BL/6 mice. Surprisingly, the only immune responses detected at 60 h postinfection occurred in the susceptible mice and only upon stimulation of cells from lymph nodes draining the inoculation site with infective larva extract: massive production of interleukin-6 (IL-6) and IL-5 (the latter cytokine was previously suspected to have an effect on L. sigmodontis growth). However, between days 10 and 30 postinfection, extraordinarily high levels of type 1 and type 2 cytokines and expansion of pleural leukocyte infiltration were seen in the resistant C57BL/6 mice, explaining the destruction of worms later. Our results suggest that events early in the infection determine susceptibility or resistance to subsequent microfilarial production and a parasite strategy to use specific immune responses to its own benefit.


2021 ◽  
Vol 12 ◽  
Author(s):  
Anna Wiszniewsky ◽  
Laura E. Layland ◽  
Kathrin Arndts ◽  
Lisa M. Wadephul ◽  
Ruth S. E. Tamadaho ◽  
...  

Despite long-term mass drug administration programmes, approximately 220 million people are still infected with filariae in endemic regions. Several research studies have characterized host immune responses but a major obstacle for research on human filariae has been the inability to obtain adult worms which in turn has hindered analysis on infection kinetics and immune signalling. Although the Litomosoides sigmodontis filarial mouse model is well-established, the complex immunological mechanisms associated with filarial control and disease progression remain unclear and translation to human infections is difficult, especially since human filarial infections in rodents are limited. To overcome these obstacles, we performed adoptive immune cell transfer experiments into RAG2IL-2Rγ-deficient C57BL/6 mice. These mice lack T, B and natural killer cells and are susceptible to infection with the human filaria Loa loa. In this study, we revealed a long-term release of L. sigmodontis offspring (microfilariae) in RAG2IL-2Rγ-deficient C57BL/6 mice, which contrasts to C57BL/6 mice which normally eliminate the parasites before patency. We further showed that CD4+ T cells isolated from acute L. sigmodontis-infected C57BL/6 donor mice or mice that already cleared the infection were able to eliminate the parasite and prevent inflammation at the site of infection. In addition, the clearance of the parasites was associated with Th17 polarization of the CD4+ T cells. Consequently, adoptive transfer of immune cell subsets into RAG2IL-2Rγ-deficient C57BL/6 mice will provide an optimal platform to decipher characteristics of distinct immune cells that are crucial for the immunity against rodent and human filarial infections and moreover, might be useful for preclinical research, especially about the efficacy of macrofilaricidal drugs.


2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Laura E. Layland ◽  
Jesuthas Ajendra ◽  
Manuel Ritter ◽  
Anna Wiszniewsky ◽  
Achim Hoerauf ◽  
...  

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