Microbiota Sensing by Mincle-Syk Axis in Dendritic Cells Regulates Interleukin-17 and -22 Production and Promotes Intestinal Barrier Integrity.

Production of interleukin-17 (IL-17) and IL-22 by T helper 17 (Th17) cells and group 3 innate lymphoid cells (ILC3s) in response to the gut microbiota ensures maintenance of intestinal barrier function. Here, we examined the mechanisms whereby the immune system detects microbiota in the steady state. A Syk-kinase-coupled signaling pathway in dendritic cells (DCs) was critical for commensal-dependent production of IL-17 and IL-22 by CD4+ T cells. The Syk-coupled C-type lectin receptor Mincle detected mucosal-resident commensals in the Peyer's patches (PPs), triggered IL-6 and IL-23p19 expression, and thereby regulated function of intestinal Th17- and IL-17-secreting ILCs. Mice deficient in Mincle or with selective depletion of Syk in CD11c+ cells had impaired production of intestinal RegIIIγ and IgA and increased systemic translocation of gut microbiota. Consequently, Mincle deficiency led to liver inflammation and deregulated lipid metabolism. Thus, sensing of commensals by Mincle and Syk signaling in CD11c+ cells reinforces intestinal immune barrier and promotes host-microbiota mutualism, preventing systemic inflammation.

Bacterial Mucosal Immunotherapy with MV130 Prevents Recurrent Wheezing in Children: A Randomized, Double-Blind, Placebo-controlled Clinical Trial.

Rationale: Recurrent wheezing in children represents a severe public health concern. Wheezing attacks (WA), mainly associated with viral infections, lack effective preventive therapies. Objectives: To evaluate the efficacy and safety of mucosal sublingual immunotherapy based on whole inactivated bacteria (MV130) in preventing WA in children. Methods: A Phase 3 randomized, double-blind, placebo-controlled, parallel-group trial including a cohort of 120 children <3 years old with ⩾3 WA during the previous year was conducted. Children with a positive skin test to common aeroallergens in the area where the clinical trial was performed were excluded from the trial. Subjects received MV130 or placebo daily for 6 months. The primary endpoint was the number of WA within 1 year after the first dose comparing MV130 and placebo. Measurements and Main Results: There was a significant lower number of WA in MV130 versus the placebo group, 3.0 (interquartile range [IQR], 2.0-4.0) versus 5.0 (IQR, 3.0-7.0) (P < 0.001). As secondary outcomes, a decrease in the duration of WA and a reduction in symptoms and medication scores in the MV130 versus placebo group were found. No adverse events were reported related to the active treatment. Conclusions: Mucosal bacterial immunotherapy with MV130 shows safety and clinical efficacy against recurrent WA in children.Clinical trial registered with www.clinicaltrials.gov (NCT01734811).

IVIg Promote Cross-Tolerance against Inflammatory Stimuli In Vitro and In Vivo.

IVIg is an approved therapy for immunodeficiency and for several autoimmune and inflammatory diseases. However, the molecular basis for the IVIg anti-inflammatory activity remains to be fully explained and cannot be extrapolated from studies on animal models of disease. We now report that IVIg impairs the generation of human monocyte-derived anti-inflammatory macrophages by inducing JNK activation and activin A production and limits proinflammatory macrophage differentiation by inhibiting GM-CSF-driven STAT5 activation. In vivo, IVIg provokes a rapid increase in peripheral blood activin A, CCL2, and IL-6 levels, an effect that can be recapitulated in vitro on human monocytes. On differentiating monocytes, IVIg promotes the acquisition of altered transcriptional and cytokine profiles, reduces TLR expression and signaling, and upregulates negative regulators of TLR-initiated intracellular signaling. In line with these effects, in vivo IVIg infusion induces a state tolerant toward subsequent stimuli that results in reduced inflammatory cytokine production after LPS challenge in human peripheral blood and significant protection from LPS-induced death in mice. Therefore, IVIg conditions human macrophages toward the acquisition of a state of cross-tolerance against inflammatory stimuli, an effect that correlates with the net anti-inflammatory action of IVIg in vivo.

MV140 Mucosal Vaccine Induces Targeted Immune Response for Enhanced Clearance of Uropathogenic E. coli in Experimental Urinary Tract Infection.

MV140 is an inactivated whole-cell bacterial mucosal vaccine with proven clinical efficacy against recurrent urinary tract infections (UTIs). These infections are primarily caused by uropathogenic E. coli (UPEC) strains, which are unique in their virulence factors and remarkably diverse. MV140 contains a non-UPEC strain, suggesting that it may induce an immune response against different UPEC-induced UTIs in patients. To verify this, we experimentally evaluated the cellular and humoral responses to UTI89, a prototypical UPEC strain, in mice vaccinated with MV140, as well as the degree of protection achieved in a UPEC UTI89 model of acute cystitis. The results show that both cellular (Th1/Th17) and antibody (IgG/IgA) responses to UTI89 were induced in MV140-immunized mice. MV140 vaccination resulted in an early increased clearance of UTI89 viable bacteria in the bladder and urine following transurethral infection. This was accompanied by a highly significant increase in CD4+ T cells in the bladder and an increase in urinary neutrophils. Collectively, our results support that MV140 induces cross-reactive humoral and cellular immune responses and cross-protection against UPEC strains.

MV140 mucosal bacterial vaccine improves uropathogenic E. coli clearance in an experimental model of urinary tract infection.

MV140 is a mucosal vaccine of inactivated whole bacteria (E. coli, K. pneumoniae, E. faecalis, P. vulgaris) with clinical efficacy against recurrent urinary tract infections (UTIs). Here, MV140 was evaluated in a murine model of acute uropathogenic E. coli (UPEC)-induced UTI using the UTI89 strain. MV140 vaccination resulted in UPEC clearance, concomitant with increased influx of myeloid cells in urine, CD4+ T cells in the bladder, and a systemic adaptive immune response to both MV140-containing E. coli and UTI89.

Bioavailability of Cariban® Capsules: A Modified-Release Fixed-Dose Combination of Doxylamine and Pyridoxine to Relieve Nausea and Vomiting During Pregnancy.

BACKGROUND: Nausea and vomiting is a very prevalent condition during pregnancy. Combination of doxylamine and pyridoxine is placed as first-line pharmacological option for its treatment in most clinical guidelines. Among different release forms available, Cariban® is a fixed-dose combination of doxylamine/pyridoxine 10/10 mg, formulated as modified-release capsules. OBJECTIVES: In the present study, we aimed to characterize the bioavailability performance of Cariban® in vitro and in vivo. METHODS: An in vitro dissolution test was performed to evaluate the release profile of Cariban®, together with immediate- and delayed-release formulations available on the market. A single-center, single-dose, open-label bioavailability study following Cariban® administration in 12 healthy adult female patients was carried out to explore the drug behavior in vivo (protocol NBR-002-13; EUDRA-CT 2013-005422-35). These data were additionally used to perform a computational pharmacokinetic simulation of the posology approved for this drug. RESULTS: Cariban® capsules demonstrate a prolonged-release performance, with an early, gradual, and progressive release of both actives until reaching a complete dissolution after 4-5 h in solution. The pharmacokinetic features of these capsules show that doxylamine and pyridoxine metabolites are early absorbed, being all detectable in plasma within 1 h following oral administration. Computational pharmacokinetic simulation predicts that different posology provides distinct profiles of metabolites in plasma, with 1-1-2 (morning-midafternoon-night) being the one that concentrates higher plasma levels but lower dose dumping for 24 h. CONCLUSION: Cariban® behaves as a prolonged-release formulation, which correlates with rapid absorption and arising of the actives in the plasma, but also long-lasting and sustained bioavailability, especially when administered following the complete posology. These results would underlie its demonstrated efficacy to relieve nausea and vomiting of pregnancy (NVP) under clinical settings.

Combination of Soy Isoflavones, 8-Prenylnaringenin and Melatonin Improves Hot Flashes and Health-Related Quality of Life Outcomes in Postmenopausal Women: Flavie Study.

OBJECTIVES: This study aims to investigate the effects of a combination of soy isoflavones, 8-prenylnaringenin (8-PN), and melatonin in postmenopausal women suffering from moderate-to-severe hot flashes (HFs). METHODS: A multicenter, prospective, open-label study enrolled 44 postmenopausal women suffering from moderate-to-severe HFs (≥ 5 daily or ≥ 35 weekly) to receive 54.4 mg standardized soy isoflavones (including 24.5 mg genistein and 16.3 mg daidzein), 100 µg 8-PN, and 1 mg melatonin once daily for 12 weeks. The primary clinical outcomes included changes in health-related quality of life (HRQoL) scores (Menopause-Specific QoL questionnaire [MENQoL] and Cervantes Scale) and HFs following 4 and 12 weeks of treatment. Other analyses included treatment adherence, acceptability, tolerability, and safety. RESULTS: All of the four domains of MENQoL questionnaire significantly improved at 4 weeks (P < 0.05) and 12 weeks (P < 0.001), affecting significantly the vasomotor, psychosocial, and physical spheres (41.2%, 26.3%, and 25.0%; 12 weeks improvements, respectively). Similarly, in the menopause (39.3%) and psychic (51.7%) domains (both P < 0.05 at 12 weeks), the global score of the Cervantes Scale significantly increased at 4 weeks (18.6%) and 12 weeks (35.4%). Accordingly, moderate-to-severe HFs significantly decreased at 4 weeks compared to baseline (41.7% reduction) and further reduced at 12 weeks (76.5%), including the total number of episodes. CONCLUSIONS: Food supplements containing soy isoflavones, 8-PN, and melatonin showed an early and progressive benefit for reducing clinically significant HFs and for improving HRQoL across all domains, favorably affecting postmenopausal women's overall well-being.

Sublingual MV140 for Prevention of Recurrent Urinary Tract Infections.

BACKGROUND: Recurrent urinary tract infections (UTIs), which consist of three or more episodes in 1 year or two or more infections in 6 months, affect 5% to 10% of women. MV140, a sublingual preparation of whole-cell inactivated bacteria, has shown clinical benefit in observational studies. This trial examined treatment with MV140 to prevent recurrent UTI. METHODS: In this multicenter, randomized, double-blind, placebo-controlled, parallel-group 1-year trial, 240 women 18 to 75 years of age from Spain and the United Kingdom with recurrent UTI were allocated to receive MV140 for 3 or 6 months or placebo for 6 months in a 1:1:1 ratio. The primary end point was the number of UTIs in the 9-month study period after 3 months of intervention. Key secondary end points were the percentage of women who were UTI free over the above period, time to UTI onset, and health-related quality of life. RESULTS: The median (interquartile range) of UTI episodes was 3.0 (0.5 to 6.0) for placebo compared with 0.0 (0.0 to 1.0) in both groups receiving MV140 (P<0.001). Among women treated with placebo, 25% (95% confidence interval [CI], 15% to 35%) were free of UTIs compared with 56% (95% CI, 44% to 67%) and 58% (95% CI, 44% to 67%) of women who received 3 and 6 months of MV140 treatment, respectively. A total of 205 AEs in 101 participants were registered (81, 76, and 48 in the placebo, 3-month MV140, and 6-month MV140 groups, respectively). CONCLUSIONS: In this controlled trial of modest size and duration, MV140 showed promising clinical efficacy in reducing recurrent UTI in women suffering from this condition. Adverse effects were not clinically limiting. (Funded by Inmunotek S.L. and Syner-Med [Pharmaceutical Products] Ltd.; ClinicalTrials.gov number, NCT02543827.)

Trained immunity induction by the inactivated mucosal vaccine MV130 protects against experimental viral respiratory infections.

MV130 is an inactivated polybacterial mucosal vaccine that confers protection to patients against recurrent respiratory infections, including those of viral etiology. However, its mechanism of action remains poorly understood. Here, we find that intranasal prophylaxis with MV130 modulates the lung immune landscape and provides long-term heterologous protection against viral respiratory infections in mice. Intranasal administration of MV130 provides protection against systemic candidiasis in wild-type and Rag1-deficient mice lacking functional lymphocytes, indicative of innate immune-mediated protection. Moreover, pharmacological inhibition of trained immunity with metformin abrogates the protection conferred by MV130 against influenza A virus respiratory infection. MV130 induces reprogramming of both mouse bone marrow progenitor cells and in vitro human monocytes, promoting an enhanced cytokine production that relies on a metabolic shift. Our results unveil that the mucosal administration of a fully inactivated bacterial vaccine provides protection against viral infections by a mechanism associated with the induction of trained immunity.

Bioavailability of Oniria®, a Melatonin Prolonged-Release Formulation, Versus Immediate-Release Melatonin in Healthy Volunteers.

BACKGROUND: Melatonin is an endogenous substance which plays a key role in sleep induction by reducing sleep onset latency; it has been approved by the European Food Safety Authority as a food supplement for exogenous administration. Oniria® is a food supplement formulated as 1.98 mg of prolonged-release melatonin tablets; it displays a dual dissolution profile in vitro. OBJECTIVES: The main objective of the present study was to evaluate the relative oral bioavailability of Oniria®, in comparison with immediate-release tablets (IRT) with a similar melatonin content as a reference. We also attempted to characterize the circadian rhythm of endogenous melatonin. METHODS: We performed an open-label, cross-over, randomized, phase I clinical study with two sequences and three periods involving 14 healthy volunteers. We characterized the endogenous melatonin circadian profile (period 1) and pharmacokinetics (PK) of both Oniria® and the reference melatonin (periods 2 and 3). RESULTS: Two phases were clearly differentiated in the PK profile of Oniria®. An initial one, from dosing up to 2 h, and a delayed one from 2 to 11 h post-administration. During the initial phase, both melatonin formulations were equivalent, with a Cmax value close to 4000 pg/mL. However, in the delayed phase, Oniria® showed significantly higher melatonin concentrations than the IRT (three times higher at 4-6 h post-administration). Moreover, Oniria® exhibited concentrations above the endogenous melatonin peak of 80 pg/mL for up to 2.5 h versus the reference formulation, potentially suggesting an effect of Oniria®, not only in the induction of sleep, but also in the maintenance. CONCLUSION: Oniria® could be a highly promising food supplement, not only for sleep induction but also for the maintenance of sleep.

SARS-CoV-2 IgG seropositivity in a cohort of 449 non-hospitalized individuals during Spanish COVID-19 lockdown.

The Coronavirus Disease of 2019 (COVID-19) pandemic caused by SARS-CoV-2 led the Spanish government to impose a national lockdown in an attempt to control the spread of the infection. Mobility restrictions and the requirement of a medical prescription for serological testing for COVID-19 were included among the control measures. Under this scenario, between April 15th and June 15th, 2020, we performed an observational study including 449 individuals allowed to be tested according to the governmental restrictions, i.e. fulfilling the following prescription requirements: manifestation of COVID-19-compatible symptoms, contact with a confirmed COVID-19 patient, or employment as an essential worker, including health care workers, firefighters and public safety personnel such as police. Importantly, a relevant feature of the studied cohort was that none of the participants had been hospitalized. We analyzed SARS-CoV-2 IgG seropositivity in this specific cohort, uncovering intrinsic features of great demographic interest. The overall rate of IgG seropositivity was 33.69% (95% CI: 29.27-38.21). This frequency was comparable among the different participant occupations. A RT-PCR positive test, contact with a household member previously tested positive and the presence of COVID-19-compatible symptoms were positively associated with IgG + results. Among these symptoms, ageusia/anosmia was positively and independently associated with SARS-CoV-2 IgG seropositivity, while odynophagia was inversely associated. However, fever, ageusia/anosmia and asthenia were the most frequent symptoms described by IgG + subjects. Therefore, our data illustrate how specific cohorts display particular characteristics that should be taken into account when studying population-wide SARS-CoV-2 seroprevalence and key defining symptoms of COVID-19.

Sublingual Bacterial Vaccination Reduces Recurrent Infections in Patients With Autoimmune Diseases Under Immunosuppressant Treatment.

Introduction: Conventional or biologic disease-modifying anti-rheumatic drugs (DMARDs) are the mainstay of treatment for systemic autoimmune disease (SAD). Infectious complications are a major concern in their use. Objective: To evaluate the clinical benefit of sublingual mucosal polybacterial vaccines (MV130 and MV140), used to prevent recurrent respiratory and urinary tract infections, in patients with SAD and secondary recurrent infections following conventional or biologic DMARDs. Methods: An observational study in SAD patients with recurrent respiratory tract infections (RRTI) and/or recurrent urinary tract infections (RUTI) was carried out. All patients underwent mucosal (sublingual) vaccination with MV130 for RRTI or with MV140 for RUTI daily for 3 months. Clinical evaluation was assessed during 12 months of follow-up after the first dose, i.e., 3 months under treatment and 9 months once discontinued, and compared with the previous year. Results: Forty-one out of 55 patients completed 1-year follow-up. All patients were on either conventional or biologic DMARDs. A significant decrease in the frequency of RUTI (p<0.001), lower respiratory tract infections (LRTI) (p=0.009) and upper respiratory tract infections (URTI) (p=0.006) at 12-mo with respect to the previous year was observed. Antibiotic prescriptions and unscheduled medical visits decreased significantly (p<0.020) in all groups. Hospitalization rate also declined in patients with RRTI (p=0.019). The clinical benefit demonstrated was concomitant to a significant increase in both anti-S. pneumoniae IgA and IgG antibodies following MV130 vaccination. Conclusions: Sublingual polybacterial vaccines prevent recurrent infections in patients with SAD under treatment with immunosuppressant therapies, supporting a broad non-specific anti-infectious effect in these patients.

Impact of whole-cell bacterial immunoprophylaxis in the management of recurrent urinary tract infections in the frail elderly.

PURPOSE: This study aimed to determine the effectiveness of whole-cell bacterial immunotherapy, i.e. MV140 and autovaccines, in reducing the number ofurinary tract infections (UTIs)in frail elderly patients with recurrent UTI (RUTI). METHOD: A prospective cohort observational study was performed including 200 frail elderly subjects suffering RUTI, both females and males, between 2016 and 2018. The effectiveness of autovaccines and the polybacterial formulation MV140 (Uromune®), consisting ofwhole-cell heat-inactivated Escherichia coli25%, Klebsiella pneumoniae25%, Proteus vulgaris25% andEnterococcus faecalis25% were evaluated. Subjects initiated a 3-month sublingually daily course with MV140 or autovaccine, either first treatment or a new course if they had been previously vaccinated prior to inclusion in the study. Number of UTIs and quality of life (QoL, SF-36 score) were measured in the different study groups. RESULTS: The mean age for participants was 82.67 (SD, 7.12) for female and 80.23 (SD, 11.12) for male subjects. In all groups, 12 months following bacterial immunotherapy, the number of UTIs significantly decreased compared to before the treatment with autovaccine or MV140: the rate of reduction ranged between 7- and 40-fold. An increase in QoL scoring was also observed in any study group. When comparing medical interventions, MV140 conferred significantly higher benefit than autovaccines. For previously vaccinated individuals, a new 3-month course with MV140 or autovaccines provided further clinical improvement. CONCLUSIONS: MV140 and autovaccines emerge as valuable immunoprophylaxis for the management of RUTI in the frail elderly, contributing to an improvement in patient's quality of life. Herein, MV140 has shown to confer a higher effectiveness compared to autovaccines, regardless sex or course of treatment.

Could sublingual vaccination be a viable option for the prevention of recurrent urinary tract infection in Canada? A systematic review of the current literature and plans for the future.

INTRODUCTION: We conducted a systematic review to examine the role of a novel sublingual vaccine - Uromune - for prevention of recurrent urinary tract infection (rUTI) to understand its potential role for Canadian women suffering from rUTI. METHODS: Databases were searched for studies published from 2010-2020 that investigated use of Uromune in the management of rUTI. Only original clinical studies that included use of Uromune as prophylaxis for uncomplicated rUTI in women that included UTI-free rate following initiation of vaccine as an outcome were included. RESULTS: Of 73 publications related to Uromune and UTIs, 19 unique clinical studies were identified evaluating Uromune for prevention of rUTI. Five studies met our inclusion criteria for primary review. These included 1408 women treated with Uromune. In two retrospective comparative studies, subjects treated with Uromune daily for three months (519 women in total) had significantly higher UTI-free rates (35-90%) than subjects treated with six months of antibiotic prophylaxis (0% in 499 women in total) over 15 months (p<0.001 for both studies). In three prospective, uncontrolled studies, UTI-free rates for subjects treated with Uromune ranged from 33-78% over 9-24 months. No major safety issues were identified in these trials. Additional unique studies evaluating Uromune for rUTI that did not meet our criteria added consistent confirmation of the potential effectiveness and safety of Uromune to prevent rUTI. CONCLUSIONS: Although these findings require confirmation in currently active, prospective clinical studies, including a randomized placebo-controlled trial, Uromune may be an alternative to antibiotics to prevent rUTI in Canadian women.

Trained Immunity Based-Vaccines as a Prophylactic Strategy in Common Variable Immunodeficiency. A Proof of Concept Study.

BACKGROUND: A major concern in the care of common variable immunodeficiency (CVID) patients is the persistence of subclinical or recurrent respiratory tract infections (RRTI) despite adequate trough IgG levels, which impacts the quality of life (QoL) and morbidity. Therefore, the development of new approaches to prevent and treat infection, especially RRTI, is necessary. OBJECTIVES: We conducted a clinical observational study from May, 2016 to December, 2017 in 20 CVID patients; ten of these patients had a history of RRTI and received the polybacterial preparation MV130, a trained immunity-based vaccine (TIbV) to assess its impact on their QoL and prognosis. METHODS: Subjects with RRTI received MV130 for 3 months and were followed up to 12 months after initiation of the treatment. The primary endpoint was a reduction in RRTI at the end of the study. We analyzed the pharmacoeconomic impact on the RRTI group before and after immunotherapy by estimating the direct and indirect costs, and assessed CVID-QoL and cytokine profile. Specific antibody responses to the bacteria contained in MV130 were measured. RESULTS: The RRTI-group treated with TIbV MV130 showed a significant decrease in infection rate (p = 0.006) throughout the 12 months after initiation of the treatment. A decrease in antibiotic use and unscheduled outpatient visits was observed (p = 0.005 and p = 0.002, respectively). Significant increases in anti-pneumococcus and anti-MV130 IgA antibodies (p = 0.039 both) were detected after 12 months of MV130. Regarding the CVID QoL questionnaire, an overall decrease in the score by more than 50% was observed (p < 0.05) which demonstrated that patients experienced an improvement in their QoL. The pharmacoeconomic analysis showed that the real annual direct costs decreased up to 4 times per patient with the prophylactic intervention (p = 0.005). CONCLUSION: The sublingual administration of the TIbV MV130 significantly reduced the rate of respiratory infections, antibiotic use and unscheduled visits, while increasing specific IgA responses in CVID patients. Additionally, the CVID population felt that their QoL was improved, and a decrease in expenses derived from health care was predicted.

Flexible Signaling of Myeloid C-Type Lectin Receptors in Immunity and Inflammation.

Myeloid C-type lectin receptors (CLRs) are important sensors of self and non-self that work in concert with other pattern recognition receptors (PRRs). CLRs have been previously classified based on their signaling motifs as activating or inhibitory receptors. However, specific features of the ligand binding process may result in distinct signaling through a single motif, resulting in the triggering of non-canonical pathways. In addition, CLR ligands are frequently exposed in complex structures that simultaneously bind different CLRs and other PRRs, which lead to integration of heterologous signaling among diverse receptors. Herein, we will review how sensing by myeloid CLRs and crosstalk with heterologous receptors is modulated by many factors affecting their signaling and resulting in differential outcomes for immunity and inflammation. Finding common features among those flexible responses initiated by diverse CLR-ligand partners will help to harness CLR function in immunity and inflammation.

DNGR-1 in dendritic cells limits tissue damage by dampening neutrophil recruitment.

Host injury triggers feedback mechanisms that limit tissue damage. Conventional type 1 dendritic cells (cDC1s) express dendritic cell natural killer lectin group receptor-1 (DNGR-1), encoded by the gene Clec9a, which senses tissue damage and favors cross-presentation of dead-cell material to CD8+ T cells. Here we find that DNGR-1 additionally reduces host-damaging inflammatory responses induced by sterile and infectious tissue injury in mice. DNGR-1 deficiency leads to exacerbated caerulein-induced necrotizing pancreatitis and increased pathology during systemic Candida albicans infection without affecting fungal burden. This effect is B and T cell-independent and attributable to increased neutrophilia in DNGR-1-deficient settings. Mechanistically, DNGR-1 engagement activates SHP-1 and inhibits MIP-2 (encoded by Cxcl2) production by cDC1s during Candida infection. This consequently restrains neutrophil recruitment and promotes disease tolerance. Thus, DNGR-1-mediated sensing of injury by cDC1s serves as a rheostat for the control of tissue damage, innate immunity, and immunopathology.

Targeting SHIP-1 in Myeloid Cells Enhances Trained Immunity and Boosts Response to Infection.

ß-Glucan-induced trained immunity in myeloid cells leads to long-term protection against secondary infections. Although previous studies have characterized this phenomenon, strategies to boost trained immunity remain undefined. We found that ß-glucan-trained macrophages from mice with a myeloid-specific deletion of the phosphatase SHIP-1 (LysMΔSHIP-1) showed enhanced proinflammatory cytokine production in response to lipopolysaccharide. Following ß-glucan training, SHIP-1-deficient macrophages exhibited increased phosphorylation of Akt and mTOR targets, correlating with augmented glycolytic metabolism. Enhanced training in the absence of SHIP-1 relied on histone methylation and acetylation. Trained LysMΔSHIP-1 mice produced increased amounts of proinflammatory cytokines upon rechallenge in vivo and were better protected against Candida albicans infection compared with control littermates. Pharmacological inhibition of SHIP-1 enhanced trained immunity against Candida infection in mouse macrophages and human peripheral blood mononuclear cells. Our data establish proof of concept for improvement of trained immunity and a strategy to achieve it by targeting SHIP-1.