Galectin-1 induces a tumor-associated macrophage phenotype and upregulates indoleamine 2,3-dioxygenase-1

Galectins are a group of carbohydrate-binding proteins with a presumed immunomodulatory role and an elusive function on antigen-presenting cells. Here we analyzed the expression of galectin-1 and found upregulation of galectin-1 in the extracellular matrix across multiple tumors. Performing an in-depth and dynamic proteomic and phosphoproteomic analysis of human macrophages stimulated with galectin-1, we show that galectin-1 induces a tumor-associated macrophage phenotype with increased expression of key immune checkpoint protein programmed cell death 1 ligand 1 (PD-L1/CD274) and immunomodulator indoleamine 2,3-dioxygenase-1 (IDO1). Galectin-1 induced IDO1 and its active metabolite kynurenine in a dose-dependent manner through JAK/STAT signaling. In a 3D organotypic tissue model system equipped with genetically engineered tumorigenic epithelial cells, we analyzed the cellular source of galectin-1 in the extracellular matrix and found that galectin-1 is derived from epithelial and stromal cells. Our results highlight the potential of targeting galectin-1 in immunotherapeutic treatment of human cancers.

Platelet transfusions in a murine model of neonatal polymicrobial sepsis: Divergent effects on inflammation and mortality

BACKGROUND

Platelet transfusions (PTxs) are often given to septic preterm neonates at high platelet count thresholds in an attempt to reduce bleeding risk. However, the largest randomized controlled trial (RCT) of neonatal transfusion thresholds found higher mortality and/or major bleeding in infants transfused at higher thresholds. Using a murine model, we investigated the effects of adult PTx on neonatal sepsis-induced mortality, systemic inflammation, and platelet consumption.

STUDY DESIGN AND METHODS

Polymicrobial sepsis was induced via intraperitoneal injection of cecal slurry preparations (CS1, 2, 3) into P10 pups. Two hours after infection, pups were transfused with washed adult Green Flourescent Protein (GFP+) platelets or control. Weights, platelet counts, and GFP% were measured before 4 and 24 h post-infection. At 24 h, blood was collected for quantification of plasma cytokines.

RESULTS

The CS batches varied in 24 h mortality (11%, 73%, and 30% in CS1, 2, and 3, respectively), due to differences in bacterial composition. PTx had differential effects on sepsis-induced mortality and systemic inflammatory cytokines, increasing both in mice infected with CS1 (low mortality) and decreasing both in mice infected with CS2 and 3. In a mathematical model of platelet kinetics, the consumption of transfused adult platelets was higher than that of endogenous neonatal platelets, regardless of CS batch.

DISCUSSION

Our findings support the hypothesis that transfused adult platelets are consumed faster than endogenous neonatal platelets in sepsis and demonstrate that PTx can enhance or attenuate neonatal inflammation and mortality in a model of murine polymicrobial sepsis, depending on the composition of the inoculum and/or the severity of sepsis.

Treatment with galectin-1 improves myogenic potential and membrane repair in dysferlin-deficient models

Limb-girdle muscular dystrophy type 2B (LGMD2B) is caused by mutations in the dysferlin gene, resulting in non-functional dysferlin, a key protein found in muscle membrane. Treatment options available for patients are chiefly palliative in nature and focus on maintaining ambulation. Our hypothesis is that galectin-1 (Gal-1), a soluble carbohydrate binding protein, increases membrane repair capacity and myogenic potential of dysferlin-deficient muscle cells and muscle fibers. To test this hypothesis, we used recombinant human galectin-1 (rHsGal-1) to treat dysferlin-deficient models. We show that rHsGal-1 treatments of 48 h-72 h promotes myogenic maturation as indicated through improvements in size, myotube alignment, myoblast migration, and membrane repair capacity in dysferlin-deficient myotubes and myofibers. Furthermore, increased membrane repair capacity of dysferlin-deficient myotubes, independent of increased myogenic maturation is apparent and co-localizes on the membrane of myotubes after a brief 10min treatment with labeled rHsGal-1. We show the carbohydrate recognition domain of Gal-1 is necessary for observed membrane repair. Improvements in membrane repair after only a 10 min rHsGal-1treatment suggest mechanical stabilization of the membrane due to interaction with glycosylated membrane bound, ECM or yet to be identified ligands through the CDR domain of Gal-1. rHsGal-1 shows calcium-independent membrane repair in dysferlin-deficient and wild-type myotubes and myofibers. Together our novel results reveal Gal-1 mediates disease pathologies through both changes in integral myogenic protein expression and mechanical membrane stabilization.

Platelet transfusions and mortality in necrotizing enterocolitis

BACKGROUND

Prior studies have suggested an association between platelet transfusions (PTXs) and worse outcomes among infants with necrotizing enterocolitis (NEC), potentially mediated by proinflammatory factors released by platelets. However, the effects of storage on platelet proinflammatory factor release and the confounding role of illness severity on NEC outcomes have not been determined.

STUDY DESIGN AND METHODS

First, neuropeptide Y (a potent splanchnic vasoconstrictor released by platelets) was measured by enzyme-linked immunosorbent assay in fresh frozen plasma and in the supernatant of leukoreduced apheresis-derived platelets at different times during storage. Next, we evaluated the relationship between PTX rates and death in a multicenter cohort of very-low-birth-weight infants with NEC, adjusting for illness severity.

RESULTS

Neuropeptide Y levels increased over time in the supernatant of leukoreduced apheresis-derived platelets and were 4.4-fold and 8.9-fold higher than in fresh frozen plasma on Days 2 and 3 of storage, respectively (p < 0.001). Among 598 very-low-birth-weight infants, 44 developed NEC. In unadjusted analysis, PTX rate was 30.3 (95% confidence interval [CI], 11.5-80.1) per 100 infant-days among infants who died, compared to 6.0 (95% CI, 3.2-11.2) among survivors (incidence rate ratio, 5.1; 95% CI, 1.6-16.2; p = 0.006). In multivariable analysis, there was no association between PTX rate and mortality (incidence rate ratio, 3.0; 95% CI, 0.6-15.0; p = 0.18), although estimation was imprecise.

CONCLUSION

Proinflammatory mediators accumulate in platelet suspensions during storage. Although PTX rates were not associated with increased mortality among infants with NEC in our study, our estimates suggest the potential for such an association that needs evaluation in larger studies.

Pathogen array reveals innate immune defense against molecular mimicry (112.16)

The microbiome regulates diverse biological processes, including general metabolism and immunity, within a given individual. However, the examination of immunological factors responsible for regulating this superorganism remains difficult. In order to overcome these current limitations, we developed a microbial glycan microarray from a diverse range of microbial species. Serological comparison between humans and mice demonstrated striking differences in reactivity toward the antigenic determinants of different species, strongly suggesting unique exposure and/or distinct immunological responses to microbial flora between organisms. More importantly, innate immune lectins, galectin-4 and galectin-8, displayed exquisite specificity for bacteria displaying self-like antigens, while failing to bind related strains with non-self-like antigens. Galectin binding to these bacteria caused death accompanied by alterations in membrane integrity, whereas binding to mammalian cells expressing similar structures had no effect on cell viability. These results demonstrate that microbial glycan microarrays provide a new platform to explore the distinct contributions of different immunological factors to a wide variety of organisms and strongly suggest that innate immune lectins exist that provide unique protection against microbial molecular mimicry.

Electrical Characteristics of Barium Strontium Titanate-Oxide Composite Films

In a previous work. composites of BSTO combined with other nonelectrically active oxide ceramics have been formulated and have demonstrated adjustable electronic properties which can be tailored for use in various electronic devices. One application has been for use in phased array antennas and insertion has been accomplished into several working antenna systems. To further accommodate the frequencies required by these phased array antennas, thin films of the composites have been fabricated using a Krypton Fluoride excimer laser as an ablation source. The electrical properties, including the dielectric constant and the tunability (change in the dielectric constant with applied voltage) have been measured. The results have been compared to those obtained for the bulk, ceramic composites and other BSTO/oxide composite thin film structures.

A LEEP Cervical Conization Is Rarely Indicated for a Two-Step Discrepancy

OBJECTIVES

The current indications for conization of the cervix include a 2-step discrepancy between cervical cytological and histological findings. We sought to determine the utility of a loop electrocautery excision procedure (LEEP) cone for a 2-step discrepancy.

METHODS

A retrospective institutional review board-approved chart review was performed on all women recommended to undergo a LEEP secondary to a discrepancy between a referral high-grade squamous intraepithelial lesion cytological finding and a subsequent colposcopic biopsy result revealing either normal or cervical intraepithelial neoplasia (CIN) 1 histological finding; CIN 2 was excluded from the study. Statistical analysis was performed using SAS 9 (SAS Institute, Inc, Cary, NC). The results were considered significant if a p value less than or equal to.05 was demonstrated.

RESULTS

Fifty-nine patients received a LEEP for a 2-step discrepancy between cytological and histological findings. Twenty-seven patients had a second pass or LEEP cone. Among the patients with a normal cervical biopsy result and a high-grade cytological finding, 10 (29%) of 34 had normal histological findings, as revealed by LEEP, and 14 (41%) of 34 had CIN 3; 16 (64%) of 25 patients with high-grade cytological finding and CIN 1 biopsy finding had CIN 3, as revealed by LEEP. Compared with patients with an initial normal cervical biopsy result, those with CIN 1 on initial biopsy were more likely to have CIN 3 on their LEEP findings (p =.08). Twenty-seven of 59 patients underwent a LEEP cone surgery; 1 of 27 had CIN 3 finding in the second-pass portion. This was associated with a CIN 3 identified on the first pass and associated with positive margins. The second pass of the LEEP cone failed to demonstrate CIN 96% of the time (p < .0001). Patients with a normal or a CIN 1 finding on the first pass had a normal finding on the second pass in 100% of cases.

CONCLUSIONS

A LEEP cone is rarely indicated for the evaluation of a 2-step discrepancy. A randomized trial of this finding is warranted.

Dimeric galectin-1 binds with high affinity to alpha2,3-sialylated and non-sialylated terminal N-acetyllactosamine units on surface-bound extended glycans

Galectin-1 is a member of the galectin family of glycan-binding proteins and occurs as an approximately 29.5-kDa noncovalent homodimer (dGal-1) that is widely expressed in many tissues. Here, we report that human recombinant dGal-1 bound preferentially and with high affinity (apparent K(d) approximately 2-4 microM) to immobilized extended glycans containing terminal N-acetyllactosamine (LN; Galbeta1-4GlcNAc) sequences on poly-N-acetyllactosamine (PL; (-3Galbeta1-4GlcNAcbeta1-)(n)) sequences, complex-type biantennary N-glycans, or novel chitin-derived glycans modified to contain terminal LN. Although terminal Gal residues are important for dGal-1 recognition, dGal-1 bound similarly to alpha3-sialylated and alpha2-fucosylated terminal LN, but not to alpha6-sialylated and alpha3-fucosylated terminal LN. The binding specificity of human recombinant dGal-1 was similar to that observed with purified bovine heart-derived dGal-1. Unexpectedly, dGal-1 bound free ligands in solution with relatively low affinity and displayed no preference for extended glycans, indicating that dGal-1 preferentially recognizes extended glycans only when they are surface-bound, such as found on cell surfaces. Human dGal-1 also bound to both native and desialylated human promyelocytic HL-60 cells with similar affinity as observed for immobilized long chain PL. Binding to these cells was reduced upon treatment with endo-beta-galactosidase, which cleaves PL sequences, indicating that cell-surface PLs are ligands. To test the role of dimerization in dGal-1 binding, we examined the binding of a mutated form of dGal-1 that weakly dimerizes (monomeric Gal-1 (mGal-1)) and a covalently dimerized (chemically cross-linked) form of mGal-1 (cd-mGal-1). dGal-1 and cd-mGal-1 had similar affinities that were both approximately 3.5-fold higher for immobilized PL than observed for mGal-1, suggesting that dGal-1 acts as a dimer to cross-link terminal LN units on immobilized PL. These results indicate that dGal-1 functions as a dimer to recognize LN units on extended PLs on cell surfaces.