Uncovering therapeutic targets for macrophage-mediated T cell suppression and PD-L1 therapy sensitization.

Tumor-associated macrophages (TAMs) and other myelomonocytic cells are implicated in regulating responsiveness to immunotherapies, including immune checkpoint inhibitors (ICIs) targeting the PD-1/PD-L1 axis. We have developed an ex vivo high-throughput approach to discover modulators of macrophage-mediated T cell suppression, which can improve clinical outcomes of ICIs. We screened 1,430 Food and Drug Administration (FDA)-approved small-molecule drugs using a co-culture assay employing bone-marrow-derived macrophages (BMDMs) and splenic-derived T cells. This identified 57 compounds that disrupted macrophage-mediated T cell suppression. Seven compounds exerted prominent synergistic T cell expansion activity when combined with αPD-L1. These include four COX1/2 inhibitors and two myeloid cell signaling inhibitors. We demonstrate that the use of cyclooxygenase (COX)1/2 inhibitors in combination with αPD-L1 decreases tumor growth kinetics and enhances overall survival in triple-negative breast cancer (TNBC) tumor models in a CD8+ T cell-dependent manner. Altogether, we present a rationalized approach for identifying compounds that synergize with ICI to potentially enhance therapeutic outcomes for patients with solid tumors.

Triple-Antibiotic Combination Exerts Effective Activity against Mycobacterium avium subsp. hominissuis Biofilm and Airway Infection in an In Vivo Murine Model.

OBJECTIVES: Slow-growing nontuberculous mycobacteria (NTMs) are highly prevalent and routinely cause opportunistic intracellular infectious disease in immunocompromised hosts. METHODS: The activity of the triple combination of antibiotics, clarithromycin (CLR), rifabutin (RFB), and clofazimine (CFZ), was evaluated and compared with the activity of single antibiotics as well as with double combinations in an in vitro biofilm assay and an in vivo murine model of Mycobacterium avium subsp. hominissuis (M. avium) lung infection. RESULTS: Treatment of 1-week-old biofilms with the triple combination exerted the strongest effect of all (0.12 ± 0.5 × 107 CFU/mL) in reducing bacterial growth as compared to the untreated (5.20 ± 0.5 × 107/mL) or any other combination (≥0.75 ± 0.6 × 107/mL) by 7 days. The treatment of mice intranasally infected with M. avium with either CLR and CFZ or the triple combination provided the greatest reduction in CLR-sensitive M. avium bacterial counts in both the lung and spleen compared to any single antibiotic or remaining double combination by 4 weeks posttreatment. After 4 weeks of treatment with the triple combination, there were no resistant colonies detected in mice infected with a CLR-resistant strain. No clear relationships between treatment and spleen or lung organ weights were apparent after triple combination treatment. CONCLUSIONS: The biofilm assay data and mouse disease model efficacy results support the further investigation of the triple-antibiotic combination.

Mindful self-compassion for veteran women with a history of military sexual trauma: feasibility, acceptability, potential benefits, and considerations.

Background: Military sexual trauma (MST) is reported by up to 74% of women veterans in the United States and is a driver of poor behavioural and physical health. Self-compassion is a transdiagnostic, protective factor linked with improved posttraumatic stress disorder (PTSD), depression, and health behaviours. Thus, Mindful Self-Compassion training (MSC) may help ameliorate MST-related impacts. However, MSC can also temporarily increase distress (i.e. backdraft). Delivering it with elective trauma-informed yoga (TIY), which regulates acute distress, may help address this issue.Objective: This VA quality improvement project examined feasibility, acceptability, and reported benefits and challenges of a manualized 8-week MSC including within non-randomized subgroups: MSC (n = 4) and MSC+ elective TIY classes (MSC+; n = 4).Methods: Nine women veterans with a history of MST at a Vet Center in the Northeastern U.S.A. enrolled; eight completed, excluding one MSC+ participant. Measures included attrition (n = 9), attendance (n = 8), weekly (n = 8) and posttreatment acceptability (n = 6), validated symptom severity assessments (n = 7), and an exit interview (n = 8).Results: Among completers, MSC attendance was excellent (89%) and higher among in MSC+ vs. MSC (94% vs. 84% sessions completed). On average across the two groups, depressive and PTSD symptom severity decreased by 21% and 30%, respectively. In exit interviews, participants across groups described improved coping with distress and psychiatric symptoms, reduced stress, and improved self-care and health behaviours. Although women in both groups reported backdraft during the programme, MSC+ also reported healthier coping and improved emotional processing.Conclusion: The results of this programme evaluation infer MSC may be feasible, acceptable, and beneficial for women survivors of MST in one Vet Center in the Northeastern USA. Further, temporary elevations in MSC-related distress may be ameliorated with adjunctive TIY. Given requests of women veterans in the USA. for additional complementary and integrative health treatment options, formal research on these approaches is warranted.

This programme evaluation with women veterans with a history of military sexual trauma (MST) explored the preliminary feasibility, acceptability, and reported benefits and challenges of a Mindful Self-Compassion (MSC) programme, with or without trauma-informed yoga.Women across groups reported improved psychiatric symptoms, self-care, and health behaviours, although those in MSC+ yoga reported healthier coping and improved emotional processing.Results suggest MSC training may be feasible, acceptable, and potentially beneficial for women veterans with MST in one clinical setting in the Northeastern USA, with potential synergistic effects of adjunctive yoga.

Environment in the lung of cystic fibrosis patients stimulates the expression of biofilm phenotype in Mycobacterium abscessus.

Introduction. Pulmonary infections caused by organisms of the Mycobacterium abscessus complex are increasingly prevalent in populations at risk, such as patients with cystic fibrosis, bronchiectasis and emphysema.Hypothesis. M. abscessus infection of the lung is not observed in immunocompetent individuals, which raises the possibility that the compromised lung environment is a suitable niche for the pathogen to thrive in due to the overproduction of mucus and high amounts of host cell lysis.Aim. Evaluate the ability of M. abscessus to form biofilm and grow utilizing in vitro conditions as seen in immunocompromised lungs of patients.Methodology. We compared biofilm formation and protein composition in the presence and absence of synthetic cystic fibrosis medium (SCFM) and evaluated the bacterial growth when exposed to human DNA.Results. M. abscessus is capable of forming biofilm in SCFM. By eliminating single components found in the medium, it became clear that magnesium works as a signal for the biofilm formation, and chelation of the divalent cations resulted in the suppression of biofilm formation. Investigation of the specific proteins expressed in the presence of SCFM and in the presence of SCFM lacking magnesium revealed many different proteins between the conditions. M. abscessus also exhibited growth in SCFM and in the presence of host cell DNA, although the mechanism of DNA utilization remains unclear.Conclusions. In vitro conditions mimicking the airways of patients with cystic fibrosis appear to facilitate M. abscessus establishment of infection, and elimination of magnesium from the environment may affect the ability of the pathogen to establish infection.

Mycobacterium avium subsp. hominissuis (MAH) Microaggregate induction of host innate immunity is linked to biofilm formation.

Bacterial aggregation is a strategy employed by many pathogens to establish infection. Mycobacterium avium subsp. hominissuis (MAH) undergoes a phenotypic change, microaggregation, when exposed to the respiratory epithelium. We therefore compared how non-aggregated bacteria, or planktonic, and microaggregated MAH can establish lung infections by evaluating mucosal epithelial cell and phagocytic cell responses. It was determined that human mucosal lung epithelial cells recognition of MAH occurs through toll-like receptors 1 and 2. MAPK 1/3 is phosphorylated at 30 min post infection, and active at the transcriptional level 2 h post infection for both phenotypes. Microaggregate infected BEAS-2B cells up-regulated CCL5, IL-1ß, and TNF-α cDNA, while planktonic infected cells only up-regulated IL-1ß cDNA at 2 h post infection. Microaggregates are associated with increased uptake by macrophages after 1 h compared to planktonic bacteria (8.83% vs. 5.00%, P < 0.05). In addition, the microaggregate phenotype, when internalized by macrophages, had reduced growth compared to planktonic bacteria, which increased when the host cells were exposed to microaggregate supernatant, obtained from the incubation of MAH with HEp-2 cells. Moreover, microaggregate supernatant stimulated biofilm formation by planktonic and microaggregated bacteria. Microaggregate supernatant also induces the production of both pro- and anti-inflammatory cytokines, which was suppressed following MAH infection. The results suggest that epithelial recognition occurs during MAH infection, and the microaggregate phenotype stimulates an inflammatory response. The initial bacterial interaction with the mucosal epithelium and development of the microaggregate phenotype has a role in pathogenesis, allowing for more robust biofilm formation and infection establishment.