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Recent evidence suggests that certain vaccines, including Bacillus-Calmette Guérin (BCG), can induce changes in the innate immune system with non-specific memory characteristics, termed ‘trained immunity’. Here we present the results of a randomised, controlled phase 1 clinical trial in 20 healthy male and female volunteers to evaluate the induction of immunity and protective efficacy of the anti-tuberculosis BCG vaccine against a controlled human malaria infection. After malaria challenge infection, BCG vaccinated volunteers present with earlier and more severe clinical adverse events, and have significantly earlier expression of NK cell activation markers and a trend towards earlier phenotypic monocyte activation. Furthermore, parasitemia in BCG vaccinated volunteers is inversely correlated with increased phenotypic NK cell and monocyte activation. The combined data demonstrate that BCG vaccination alters the clinical and immunological response to malaria, and form an impetus to further explore its potential in strategies for clinical malaria vaccine development. Immune activation induces long-term alterations of setpoints, impacting responses to subsequent unrelated stimuli. Here the authors show that volunteers vaccinated with BCG respond to controlled human malaria infection with increased clinical symptoms and an inverse correlation between immune activation markers and parasitemia.

Background Monocyte subsets differentially influence pathophysiology of heart failure and atrial fibrillation (AF) through inflammation, fibrosis, and angiogenesis. Spironolactone has antifibrotic properties. This study investigated the effect spironolactone on monocyte subsets and monocyte effects for peak oxygen consumption (peakVO2), diastolic function and brain natriuretic peptide (BNP) in the IMPRESS-AF randomised controlled trial population (2-year treatment with spironolactone 25 mg vs placebo). Methods CD14++CD16-CCR2+(Mon1), CD14++CD16+CCR2+(Mon2) and CD14+CD16++CCR2-(Mon3) monocyte subsets were analysed by flow cytometry and compared between spironolactone and placebo groups at 12 months and 24 months after randomisation. PeakVO2, diastolic function (echocardiographic E/'e) and BNP were measured at baseline and 24 months. Linear regression was used to assess the effects of monocytes on the outcomes (Python 3.10 modules). Results Monocyte data were available in 225 (90%) IMPRESS-AF patients (age 72[67-77], 78% male). At 12-month the spironolactone group had fewer Mon3 (50[36-74] vs 60[44-90] cells/microL, p =0.02), and lower CD14 expression on Mon1 (1.37[1.17-1.59] vs 1.48[1.24-1.70], p =0.04); no difference remained by 24 months ( p >0.05). A high 12-month Mon1 count independently predicted lower E/e’ at 24 months ( p =0.02). Conclusions Spironolactone temporarily reduced proinflammatory monocyte markers (Mon3 count and CD14 expression on Mon1). Mon1 may have a positive effect on diastolic dysfunction in AF.

The immune system is affected by the dietary products humans intake. Immune system regulation by nutrition has uses in the clinical context, but it can also benefit healthy populations by delaying or preventing the emergence of immune-mediated chronic illnesses. In this study, the purpose was to describe and compare the modulator effects on the immune system of the routine ingestion of fresh vs. pasteurized yogurt. A unicentral, prospective, randomized, double-blind, parallel group 8-week nutritional study was carried out comparing the ingestion of 125 g of the products in healthy adults three times a day. A complete battery of in vitro tests on the activity of the immune system, processes and phenomena was performed. Exclusive immune-modulatory effects of fresh yogurt with respect to base line were found in terms of increased systemic IgM (primary immune responses), increased synthesis of IFN-gamma upon stimulation (Th1) and increased peripheral T cells (mainly “naive” CD4s). In the three interventions, we observed an increased phagocytic activity and burst test in granulocytes, together with increased secretion of IL-6, IL-1 β and IL-8 (pro-inflammatory) and increased CD16 expression (FcR favoring phagocytosis) in granulocytes. Overall, it is concluded that regardless of bacteria being alive or thermally inactivated, yogurt has common effects on the innate system, but the presence of live bacteria is necessary to achieve a potentiating effect on the specific immune response.

Besides the interest of an early detection of ovarian cancer, there is an urgent need for new predictive and prognostic biomarkers of tumor development and cancer treatment. In healthy patients, circulating blood monocytes are typically subdivided into classical (85%), intermediate (5%) and non-classical (10%) populations. Although these circulating monocyte subsets have been suggested as biomarkers in several diseases, few studies have investigate their potential as a predictive signature for tumor immune status,tumor growth and treatment adaptation. In this study, we used a homogeneous cohort of 28 chemotherapy-naïve patients with ovarian cancer to evaluate monocyte subsets as biomarkers of the ascites immunological status. We evaluated the correlations between circulating monocyte subsets and immune cells and tumor burden in peritoneal ascites. Moreover, to validate the use of circulating monocyte subsets tofollow tumor progression and treatment response, we characterized blood monocytes from ovarian cancer patients included in a phase 1 clinical trial at baseline and following murlentamab treatment. We demonstrate here a robust expansion of the intermediate blood monocytes (IBMs) in ovarian cancer patients. We establish a significant positive correlation between IBM percentage and tumor-associate macrophages with a CCR2 /CD163 /CD206 /CD86 profile. Moreover, IBM expansion is associated with a decreased effector/regulatory T-cell ratio in ascites and with the presence of soluble immunosuppressive mediators. We also establish that IBM proportion positively correlates with the peritoneum tumor burden. Finally, the study of IBMs in patients with ovarian cancer under immunotherapy during the phase clinical trial supports IBMs to follow the evolution of tumor development and the treatment adaptation. This study, which links IBM level with immunosuppression and tumor burden in peritoneum, identifies IBMs as apotential predictive signature of ascites immune status and as a biomarker ofovarian cancer development and treatment response. EudraCT: 2015-004252-22 NCT02978755.

Respiratory syncytial virus (RSV) causes significant lower-respiratory-tract disease in high-risk groups. A phase IIb trial showed that a combination vaccine of Ad26-vectored prefusion RSV F (Ad26.preF) plus soluble prefusion F protein (SpreF) was 80 % protective, yet the longevity and functionality of these humoral responses are unknown. Sera from vaccinated adults were analyzed 12 months after the primary dose and 28 days after a homologous booster at 1 year. IgG subclasses, isotypes, Fc-γ receptor (FcγR) binding, and Fc-dependent effector functions including opsinophagocytosis against RSV-F subtypes A and B were quantified via Systems Serology. A single dose generated durable immunity: IgG3-driven opsonophagocytic activity and broad FcγR engagement (via IgG1, IgG2, and IgG3) persisted through 12 months without appreciable decay. The booster did not increase antibody titres, FcγR binding, or functional activity, indicating that the primary response had already plateaued. One dose of Ad26.preF + SpreF elicits a long-lasting, functionally potent humoral response that is not further enhanced by a booster at 12 months, suggesting limited benefit from early re-vaccination. Continued follow-up will clarify the duration of protection and inform booster timing in vulnerable populations.

Anetumab ravtansine, like other ADC drugs, has high inter‐patient variability in its pharmacokinetic (PK) and pharmacodynamic (PD) outcomes, which raises concerns about whether current dosing regimens are optimal for patients. The objective of this study was to evaluate covariates, especially body habitus and the innate immune system (IIS), which may affect anetumab ravtansine PK and PD as part of two clinical trials in patients with ovarian cancer and mesothelioma. Biomarkers of Fcγ receptors(FcγR) CD64 on IIS cells, total body weight (TBW), body surface area (BSA), and other covariates, such as sex and age, were analyzed for an association with anetumab ravtansine PK. Higher FcγR CD64, TBW, and BSA were associated with higher clearance (CL) of anetumab ravtansine (p < 0.05). However, there was no relationship between TBW or BSA and FcγR CD64. Female patients had a lower anetumab ravtansine CL (0.030 ± 0.007 L/h) compared to male patients (0.042 ± 0.006 L/h) (p < 0.05). In both studies, patients with stable disease (SD) and partial response (PR) had higher anetumab ravtansine AUC0‐inf compared to patients with progressive disease (PD). Individualizing the dose of anetumab ravtansine and potentially other ADCs based only on TBW is not optimal, whereas precision dosing of an ADC based on the inclusion of novel metrics of IIS biomarkers, body habitus, and sex may be more appropriate to reduce variability in PK exposure, reduce toxicity, and improve response.

Dietary probiotics supplementation exerts beneficial health effects. Since cigarette smoking reduces natural killer (NK) activity, we evaluated the effect of Lactobacillus casei Shirota (LcS) intake on NK cytotoxic activity in male smokers. The double-blind, placebo-controlled, randomised study was conducted on seventy-two healthy Italian blue-collar male smokers randomly divided for daily intake of LcS powder or placebo. Before and after 3 weeks of intake, peripheral blood mononuclear cells were isolated and NK activity and CD16 + cells' number were assessed. Daily LcS intake for 3 weeks significantly increased NK activity ( P  < 0·001). The increase in NK activity was paralleled by an increase in CD16 + cells ( P  < 0·001). Before intake, NK cytotoxic activity inversely correlated with the number of cigarettes smoked ( R − 0·064). LcS intake prevented the smoke-dependent expected NK activity reduction. The analysis of the distribution of changes in smoke-adjusted NK activity demonstrated that the positive variations were significantly associated with LcS intake, while the negative variations were associated with placebo intake (median value of distributions of differences, 20·98 lytic unit (LU)/10 7 cells for LcS v. − 4·38 LU/10 7 cells for placebo, P  = 0·039). In conclusion, 3 weeks of daily LcS intake in Italian male smokers was associated with a higher increase in cytotoxic activity and CD16 + cells' number in comparison to the placebo intake group.

Defects in neutrophil function have been implicated in a wide spectrum of clinical conditions. Several models are employed to study activated human neutrophils akin to those found at a site of inflammation. These include whole blood (WB) ex vivo stimulation with lipopolysaccharide (LPS) and in vivo techniques: cantharidin blister, skin windows and intra-dermal injection of UV-killed E.coli (UVKEc). Neutrophils obtained from these have never been compared. We compared the activation status of neutrophils from each technique in order to inform the optimal model for use in human studies. Healthy male volunteers were randomised to undergo one of the four techniques (n = 5/group). LPS: WB stimulated with 1ng/ml of LPS for 4 hours. Cantharidin: 12.5μl of 0.1% cantharidin elicited a single blister, aspirated at 24 hours. Skin windows: four 6mm mechanical-suction blisters created, de-roofed and an exudate-collection chamber placed over the windows for 4 hours before aspiration. UVKEc: 1.5 x 107 UVKEc injected intra-dermally. A single 10mm mechanical-suction blister formed and aspirated at 4 hours. Unstimulated WB used as the control. Flow cytometry was used to determine activation status using CD16, CD11b, CD54, CD62L and CD88. Functional status was assessed with a phagocytosis assay. The pattern of neutrophil activation was similar in all models. Neutrophil CD11b was elevated in all models, most markedly in UVKEc (p<0.0001), and CD54 was also elevated but only significant in the LPS model (p = 0.001). CD62L was significantly reduced in all 4 models (p<0.0001) and CD88 was also suppressed in all. There were no changes in CD16 in any model, neither was there any significant difference in the phagocytic capacity of the neutrophils. In summary, there are no significant differences in activation marker expression or phagocytic capacity in the neutrophils obtained from each technique. Therefore we believe whole blood stimulation is the best model in experimentally challenging inpatient populations.

The aim of the present study was to investigate leucocyte markers, CD11b, CD16, CD66b, CD68, myeloperoxidase and neutrophil elastase on skeletal muscle biopsies from biceps brachii after unaccustomed eccentric exercise followed by the second bout of exercise 3 weeks later. The subjects (10 subjects received COX-2 inhibitor (Celecoxib) and 13 subjects received placebo) were divided into three categories: mild, moderate and severe effect of eccentric exercise, according to the reduction and recovery of muscle force-generating capacity after performing 70 maximal eccentric actions with elbow flexors on an isokinetic dynamometer. The results showed that the CD66b antibody was applicable for localization of neutrophils in human skeletal muscle, whereas the other studied neutrophil markers recognized also other leucocytes than neutrophils. The number of CD66b positive cells in skeletal muscle was very low and was not affected by the exercise. The macrophage marker CD68 showed reactivity also against satellite cells and fibroblast-like cells in skeletal muscle and therefore cannot be applied as a quantitative value for inflammatory cells. Skeletal muscle fibre injury, shown as dystrophin negative fibres, was observed approximately in half of the biopsies at 4 and 7 days after the first exercise bout in the categories moderate and severe effect of eccentric exercise. These subjects represent the most prominent loss in muscle force-generating capacity both at the category and the individual levels. Furthermore, deformed skeletal muscle fibres were observed in five subjects in these categories after the second bout of exercise. The present results suggest that neutrophils are not involved in skeletal muscle fibre injury and the reduction in muscle force-generating capacity after a single bout of eccentric exercise is a good indirect indicator of muscle damage in humans. Furthermore, prolonged regeneration process could be one of the reasons for impaired peripheral muscle function after high-force eccentric exercise.

Elimination of the binding of immunoglobulin Fc to Fc gamma receptors (FcγR) is highly desirable for the avoidance of unwanted inflammatory responses to therapeutic antibodies and fusion proteins. Many different approaches have been described in the literature but none of them completely eliminates binding to all of the Fcγ receptors. Here we describe a set of novel variants having specific amino acid substitutions in the Fc region at L234 and L235 combined with the substitution G236R. They show no detectable binding to Fcγ receptors or to C1q, are inactive in functional cell-based assays and do not elicit inflammatory cytokine responses. Meanwhile, binding to FcRn, manufacturability, stability and potential for immunogenicity are unaffected. These variants have the potential to improve the safety and efficacy of therapeutic antibodies and Fc fusion proteins.