scholarly journals Akkermansia Muciniphila induces chronic extramedullary hematopoiesis through cooperative IL-1R and TLR signals

2022 ◽  
Author(s):  
Yuxin Wang ◽  
Tatsuya Morishima ◽  
Maiko Sezaki ◽  
Gaku Nakato ◽  
Shinji Fukuda ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Interleukin 1 ◽  
Extramedullary Hematopoiesis ◽  
Commensal Bacteria ◽  
Host Immune System ◽  
Systemic Injection ◽  
Hematopoietic Stem ◽  
Akkermansia Muciniphila ◽  
Degrading Bacterium ◽  
The Impact

Bacterial infections can activate and mobilize hematopoietic stem and progenitor cells (HSPCs) from the bone marrow (BM) to spleen, which is termed as extramedullary hematopoiesis (EMH). Recent studies suggest that commensal bacteria, particularly the microbiota, regulates not only the host immune system but also hematopoietic homeostasis. However, the impact of gut microbial species on hematopoietic pathology remains largely unknown. Here we found that systemic injection of Akkermansia muciniphila (A. m.), a mucin-degrading bacterium abundantly existing in the human gut rapidly activates BM myelopoiesis, and induces a slow but long-lasting hepato-splenomegaly, characterized by the expansion and differentiation of functional HSPCs, which we termed chronic EMH. Genetic deletion of Toll-like receptor-2 and -4 (TLR2/4) partially diminished A. m.-induced chronic EMH, while additional pharmacological inhibition of the interleukin-1 receptor (IL-1R) completely alleviated splenomegaly and EMH. Our results demonstrate that cooperative IL-1R- and TLR-mediated innate immune signals regulate commensal bacteria-driven EMH, which might be relevant for certain autoimmune disorders.

An interleukin-1 receptor fragment inhibits spontaneous sleep and muramyl dipeptide-induced sleep in rabbits

1996 ◽  
Vol 271 (1) ◽  
pp. R101-R108 ◽  
Author(s):  
S. Takahashi ◽  
L. Kapas ◽  
J. Fang ◽  
J. M. Seyer ◽  
Y. Wang ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Interleukin 1 ◽  
Muramyl Dipeptide ◽  
Type I ◽  
Amino Acid Residues ◽  
Central Administration ◽  
Sleep Regulation ◽  
Systemic Injection ◽  
Normal Sleep ◽  
Receptor Fragment

Interleukin-1 (IL-1) is hypothesized to be involved in physiological sleep regulation and in sleep responses occurring during infectious disease. If this hypothesis is correct, then inhibition of endogenous IL-1 should reduce both normal sleep and N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP)-induced sleep. MDP is a somnogenic substance derived from bacterial cell walls. We report here the effects of a synthetic IL-1 receptor fragment corresponding to amino acid residues 86-95 of the human type I IL-1 receptor (IL-1RF) on spontaneous sleep and IL-1 beta- and MDP-induced sleep and fever in rabbits. Two doses of the IL-1RF (25 and 50 micrograms) were injected into normal rabbits intracerebroventricularly (icv). Both doses significantly decreased spontaneous non-rapid eye movement sleep (NREMS) across a 22-h recording period. Pretreatment of rabbits with 25 micrograms of IL-1RF blocked the somnogenic actions of 10 ng icv IL-1. Similarly, central pretreatment of animals with 25 micrograms IL-1RF significantly attenuated the NREMS-promoting and REMS-suppressive actions of 150 pmol MDP injected centrally. The increase in NREMS and decrease in REMS induced by systemic injection of 12.5 micrograms/kg MDP were also significantly suppressed by central administration of 50 micrograms IL-1RF. In contrast, the febrile response induced by either intracerebroventricularly or intravenously injected MDP were not significantly affected by IL-1RF. These results support the hypothesis that endogenous, brain-derived IL-1 contributes to the maintenance of normal sleep and may mediate sleep responses to systemic as well as central bacterial infections.

Impact of Prophylaxis with Aerosolized Amphotericin-B Deoxycholate (d-AmB) on Respiratory Tract Invasive Fungal Infections (IFIs) after Allogeneic Hematopoietic Stem Cell Transplantation (HSCT).

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4986-4986
Author(s):  
Enrico Morello ◽  
Irene M. Cavattoni ◽  
Pietro Fabris ◽  
Silvia Coin ◽  
Barbara Amato ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Bacterial Infections ◽  
Fungal Infections ◽  
Unrelated Donor ◽  
X Rays ◽  
Hematopoietic Stem ◽  
Allogeneic Hsct ◽  
Number Of Patients ◽  
Increased Risk ◽  
The Impact

Abstract Background and aims IFIs still pose major challenges in HSCT, and effective prophylaxis remains a matter of debate. The aim of this retrospective study was to evaluate the impact of aerosolized d-AmB on respiratory tract IFIs in a homogeneous cohort of allogeneic HSCT patients, transplanted at our institution. Patients and methods Since 1999, 81 consecutive patients were transplanted from matched related (N=61) or unrelated donor (MUD). Analysis was performed on 74 evaluable patients, in order to monitor the prevalence of respiratory tract IFIs within 40 days after HSCT, according to current guidelines (possible, probable, proven IFIs). Conventional antifungal prophylaxis was based on the association of fluconazole (400 mg/d), plus aerosolized d-AmB (15 mg bid) in 54 out of 74 cases (73%). All the patients were screened before transplant and monitored thereafter with CT or x-rays (paranasal sinuses, thorax), surveillance swabs and galactomannan antigenemia. Chi square test was performed to evaluate correlations between variables. Results Aerosolised d-AmB was administered to 70 patients for a median time of 15 days (range 1–45). Prolonged administration was not associated with increased severe bacterial infections, nor severe adverse events were observed; only a patient developed moderate bronchial spasm. In 13 pts, aerosolized d-AmB was delivered for less than 7 days, due to worsened clinical conditions, or poor compliance. In this group, proven IFIs were diagnosed in 2 patients (1 mucormycosis and 1 fusariosis), possible aspergillosis in one and probable aspergillosis in another one. A shortened administration (<7 days) of aerosolized d-AmB was associated with an increased risk of IFIs (p=0,002). Overall, 95% of patients did not experience IFIs and nobody died due to IFIs. Nine patients had a pre-transplant nasal swab positive for Aspergillus spp., and 8 of them received Aerosolized d-AmB; subsequent surveillance swabs proved negative. On the other hand, the only patient with positive swab who was not able to receive aerosolized d-AmB due to bronchial spasm developed a possible aspergillosis. Discussion Despite the low number of patients, prolonged aerosolized d-AmB seems to play a role in preventing respiratory tract IFIs, but a randomised controlled trial is recommended to verify the impact of this prophylaxis in the setting of allogeneic HSCT.

scholarly journals 15-PGDH Inhibition Activates the Splenic Niche to Promote Hematopoietic Regeneration

2020 ◽  
Author(s):  
Julianne N.P. Smith ◽  
Dawn M. Dawson ◽  
Kelsey F. Christo ◽  
Alvin P. Jogasuria ◽  
Mark J. Cameron ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Steady State ◽  
Mast Cells ◽  
Enzymatic Activity ◽  
Progenitor Cell ◽  
Cell Types ◽  
Extramedullary Hematopoiesis ◽  
Hematopoietic Stem ◽  
Hsc Niche ◽  
The Impact

AbstractThe splenic microenvironment regulates hematopoietic stem and progenitor cell (HSPC) function, particularly during demand-adapted hematopoiesis, however practical strategies to enhance splenic support of transplanted HSPCs have proven elusive. We have previously demonstrated that inhibiting 15-hydroxyprostaglandin dehydrogenase (15-PGDH), using the small molecule (+)SW033291 (PGDHi), increases bone marrow (BM) prostaglandin E2 (PGE2) levels, expands HSPC numbers, and accelerates hematologic reconstitution following BM transplantation (BMT) in mice. Here we demonstrate that the splenic microenvironment, specifically 15-PGDH high-expressing macrophages (MΦs), megakaryocytes (MKs), and mast cells (MCs), regulates steady-state hematopoiesis and potentiates recovery after BMT. Notably, PGDHi-induced neutrophil, platelet, and HSPC recovery were highly attenuated in splenectomized mice. PGDHi induced non-pathologic splenic extramedullary hematopoiesis at steady-state, and pre-transplant PGDHi enhanced the homing of transplanted cells to the spleen. 15-PGDH enzymatic activity localized specifically to MΦs, MK lineage cells, and MCs, identifying these cell types as likely coordinating the impact of PGDHi on splenic HSPCs. These findings suggest that 15-PGDH expression marks novel HSC niche cell types that regulate hematopoietic regeneration. Therefore, PGDHi provides a well-tolerated strategy to therapeutically target multiple HSC niches and to promote hematopoietic regeneration and improve clinical outcomes of BMT.

scholarly journals Rifaximin use favoured micafungin-resistant Candida spp. infections in recipients of allogeneic hematopoietic cell transplantation

2021 ◽  
Author(s):  
Francesca Marzuttini ◽  
Antonella Mancusi ◽  
Samanta Bonato ◽  
Mario Griselli ◽  
Sara Tricarico ◽  
...  
Keyword(s):  
Cell Transplantation ◽  
Bacterial Infections ◽  
Hematopoietic Cell Transplantation ◽  
Standard Of Care ◽  
University Hospital ◽  
Candida Spp ◽  
Hematopoietic Stem ◽  
Effective Prophylaxis ◽  
Life Threatening ◽  
The Impact

AbstractDamage to gut mucosa following conditioning regimens may favour bacterial infections that can trigger graft versus host disease (GvHD) in patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). Rifaximin, an oral and non-absorbable antibiotic, has been recently proposed as effective prophylaxis to reduce bacterial infections in the gut and consequently acute GvHD in this setting. The present study evaluated safety and outcomes of HSCT patients that were treated with rifaximin prophylaxis at Perugia University Hospital. Rifaximin prophylaxis was introduced as standard of care in HSCT patients in May 2018. We retrieved data from 118 consecutive transplants, and we compared the outcomes of rifaximin-treated patients with historical controls that did not receive antibiotic prophylaxis. While incidences of neutropenic fever, documented bacterial infections, and aGvHD were similar in the two groups, we found an increased frequency of invasive candidiasis and clinically relevant Candida spp. infections in rifaximin-treated patients (5 patients vs 1 patient, 25% [± 0.99%] vs 1% [± 0.01%], p < .0001). Three rifaximin-treated patients experienced life-threating candidemia (2 C. krusei, 1 C. orthopsilosis). Rifaximin was the only factor that increased the risk of Candida spp. infections. Rifaximin could have contributed to microbiome disruption which favoured an outbreak of life-threatening Candida infections. This important complication forced us to halt its use. Larger, prospective studies are needed to assess the impact of rifaximin prophylaxis on incidence of bacterial infections, aGvHD, and survival of HSCT patients.

scholarly journals Investigating the impact of combination phage and antibiotic therapy: a modeling study

2020 ◽  
Author(s):  
Selenne Banuelos ◽  
Hayriye Gulbudak ◽  
Mary Ann Horn ◽  
Qimin Huang ◽  
Aadrita Nandi ◽  
...  
Keyword(s):  
Immune System ◽  
Combination Therapy ◽  
Bacterial Infections ◽  
Phage Therapy ◽  
Antibiotic Use ◽  
Host Immune System ◽  
Drug Classes ◽  
The Impact ◽  
Antibiotic Combination

AbstractAntimicrobial resistance (AMR) is a serious threat to global health today. The spread of AMR, along with the lack of new drug classes in the antibiotic pipeline, has resulted in a renewed interest in phage therapy, which is the use of bacteriophages to treat pathogenic bacterial infections. This therapy, which was successfully used to treat a variety of infections in the early twentieth century, had been largely dismissed due to the discovery of easy to use antibiotics. However, the continuing emergence of antibiotic resistance has motivated new interest in the use of phage therapy to treat bacterial infections. Though various models have been developed to address the AMR-related issues, there are very few studies that consider the effect of phage-antibiotic combination therapy. Moreover, some of biological details such as the effect of the immune system on phage have been neglected. To address these limitations, we utilized a mathematical model to examine the role of the immune response in concert with phage-antibiotic combination therapy compounded with the effects of the immune system on the phages being used for treatment. We explore the effect of phage-antibiotic combination therapy by adjusting the phage and antibiotics dose or altering the timing. The model results show that it is important to consider the host immune system in the model and that frequency and dose of treatment are important considerations for the effectiveness of treatment. Our study can lead to development of optimal antibiotic use and further reduce the health risks of the human-animal-plant-ecosystem interface caused by AMR.

scholarly journals The Gut Microbiota and Hematopoietic Stem Cell Transplantation: Challenges and Potentials

2018 ◽  
Vol 11 (5) ◽  
pp. 405-415 ◽  
Author(s):  
Fozia Noor ◽  
Anne Kaysen ◽  
Paul Wilmes ◽  
Jochen G. Schneider
Keyword(s):  
Stem Cell ◽  
Hematopoietic Stem Cell Transplantation ◽  
Gut Microbiota ◽  
Stem Cell Transplantation ◽  
Cell Transplantation ◽  
Hematopoietic Stem Cell ◽  
Host Immune System ◽  
Hematopoietic Stem ◽  
Tremendous Importance ◽  
The Impact

The human gut microbiota gained tremendous importance in the last decade as next-generation technologies of sequencing and multiomics analyses linked the role of the microbial communities to host physiology and pathophysiology. A growing number of human pathologies and diseases are linked to the gut microbiota. One of the main mechanisms by which the microbiota influences the host is through its interactions with the host immune system. These interactions with both innate and adaptive host intestinal and extraintestinal immunity, although usually commensalistic even mutualistic with the host, in some cases lead to serious health effects. In the case of allogenic hematopoietic stem cell transplantation (allo-HSCT), the disruption of the intestinal microbiota diversity is associated with acute graft-versus-host disease (GvHD). Causing inflammation of the liver, skin, lungs, and the intestine, GvHD occurs in 40–50% of patients undergoing allo-HSCT and results in significant posttransplantation mortality. In this review, we highlight the impact of the gut microbiota on the host immunity in GvHD and the potential of microbiota in alleviation or even prevention of GvHD.

scholarly journals Effect of Early Post-Transplantation Tacrolimus Concentration on the Risk of Acute Graft-Versus-Host Disease in Allogenic Stem Cell Transplantation

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 613
Author(s):  
Nidhi Sharma ◽  
Qiuhong Zhao ◽  
Bin Ni ◽  
Patrick Elder ◽  
Marcin Puto ◽  
...  
Keyword(s):  
Stem Cell ◽  
Graft Versus Host Disease ◽  
Tacrolimus Concentration ◽  
Cell Transplant ◽  
Hematopoietic Stem ◽  
Host Disease ◽  
Graft Versus Host ◽  
The Impact ◽  
Risk Of Relapse ◽  
Acute Graft

Acute graft versus host disease (aGVHD) remains a leading cause of morbidity and mortality in allogeneic hematopoietic stem cell transplant (allo-HSCT). Tacrolimus (TAC), a calcineurin inhibitor that prevents T-cell activation, is commonly used as a GVHD prophylaxis. However, there is variability in the serum concentrations of TAC, and little is known on the impact of early TAC levels on aGVHD. We retrospectively analyzed 673 consecutive patients undergoing allo-HSCT at the Ohio State University between 2002 and 2016. Week 1 TAC was associated with a lower risk of aGVHD II–IV at TAC level ≥10.15 ng/mL (p = 0.03) compared to the lowest quartile. The cumulative incidence of relapse at 1, 3 and 5 years was 33%, 38% and 41%, respectively. TAC levels at week 2, ≥11.55 ng/mL, were associated with an increased risk of relapse (p = 0.01) compared to the lowest quartile. Subset analysis with acute myeloid leukemia and myelodysplastic syndrome patients showed significantly reduced aGVHD with TAC level ≥10.15 ng/mL at week 1 and a higher risk of relapse associated with week 2 TAC level ≥11.55 ng/mL (p = 0.02). Hence, achieving ≥10 ng/mL during the first week of HCT may mitigate the risk of aGVHD. However, levels (>11 ng/mL) beyond the first week may be associated with suppressed graft versus tumor effect and higher relapse.

scholarly journals The lung–gut axis during viral respiratory infections: the impact of gut dysbiosis on secondary disease outcomes

2021 ◽  
Author(s):  
Valentin Sencio ◽  
Marina Gomes Machado ◽  
François Trottein
Keyword(s):  
Gut Microbiota ◽  
Bacterial Infections ◽  
Respiratory Infections ◽  
Critical Role ◽  
Good Health ◽  
Disease Outcomes ◽  
And Function ◽  
Viral Respiratory Infections ◽  
The Impact ◽  
Viral Respiratory

AbstractBacteria that colonize the human gastrointestinal tract are essential for good health. The gut microbiota has a critical role in pulmonary immunity and host’s defense against viral respiratory infections. The gut microbiota’s composition and function can be profoundly affected in many disease settings, including acute infections, and these changes can aggravate the severity of the disease. Here, we discuss mechanisms by which the gut microbiota arms the lung to control viral respiratory infections. We summarize the impact of viral respiratory infections on the gut microbiota and discuss the potential mechanisms leading to alterations of gut microbiota’s composition and functions. We also discuss the effects of gut microbial imbalance on disease outcomes, including gastrointestinal disorders and secondary bacterial infections. Lastly, we discuss the potential role of the lung–gut axis in coronavirus disease 2019.

scholarly journals Post-transplant cyclophosphamide containing regimens after matched sibling, matched unrelated and haploidentical donor transplants in patients with acute lymphoblastic leukemia in first complete remission, a comparative study of the ALWP of the EBMT

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jaime Sanz ◽  
Jacques-Emmanuel Galimard ◽  
Myriam Labopin ◽  
Boris Afanasyev ◽  
Moiseev Ivan Sergeevich ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Cumulative Incidence ◽  
Lymphoblastic Leukemia ◽  
Hematopoietic Stem ◽  
Free Survival ◽  
Post Transplant ◽  
Gvhd Prophylaxis ◽  
Donor Type ◽  
Matched Sibling ◽  
The Impact

Abstract Background There is no information on the impact of donor type in allogeneic hematopoietic stem cell transplantation (HCT) using homogeneous graft-versus-host (GVHD) prophylaxis with post-transplant cyclophosphamide (PTCy) in acute lymphoblastic leukemia (ALL). Methods We retrospectively analyzed outcomes of adult patients with ALL in CR1 that had received HCT with PTCy as GVHD prophylaxis from HLA-matched sibling (MSD) (n = 78), matched unrelated (MUD) (n = 94) and haploidentical family (Haplo) (n = 297) donors registered in the EBMT database between 2010 and 2018. The median follow-up period of the entire cohort was 2.2 years. Results Median age of patients was 38 years (range 18–76). Compared to MSD and MUD, Haplo patients received peripheral blood less frequently. For Haplo, MUD, and MSD, the cumulative incidence of 100-day acute GVHD grade II–IV and III–IV, and 2-year chronic and extensive chronic GVHD were 32%, 41%, and 34% (p = 0.4); 13%, 15%, and 15% (p = 0.8); 35%, 50%, and 42% (p = 0.01); and 11%, 17%, and 21% (p = 0.2), respectively. At 2 years, the cumulative incidence of relapse and non-relapse mortality was 20%, 20%, and 28% (p = 0.8); and 21%, 18%, and 21% (p = 0.8) for Haplo, MUD, and MSD, respectively. The leukemia-free survival, overall survival and GVHD-free, relapse-free survival for Haplo, MUD, and MSD was 59%, 62%, and 51% (p = 0.8); 66%, 69%, and 62% (p = 0.8); and 46%, 44%, and 35% (p = 0.9), respectively. On multivariable analysis, transplant outcomes did not differ significantly between donor types. TBI-based conditioning was associated with better LFS. Conclusions Donor type did not significantly affect transplant outcome in patient with ALL receiving SCT with PTCy.

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