In Vivo Zymosan Treatment Induces IL15-Secreting Macrophages and KLRG1-Expressing NK Cells in Mice

Beta-glucan (β-glucan) is a natural polysaccharide produced by fungi, bacteria, and plants. Although it has been reported that β-glucan enhances innate immune memory responses, it is unclear whether different types of β-glucans display similar immune effects. To address this issue, we employed zymosan (β-1,3-glycosidic linkage) and pustulan (β-1,6-glycosidic linkage) to investigate their in vivo effects on innate memory immune responses. We examined the changes of innate memory-related markers in macrophages and natural killer (NK) cells, two immune cell types that display innate memory characteristics, at two different time points (16 h and 7 days) after β-glucan stimulation. We found that short-term (16 h) zymosan treatment significantly induced macrophages to upregulate IL15 production and increased surface IL15Rα expression on NK cells. In addition, long-term (7 days) zymosan treatment significantly induced macrophages to upregulate the expression of innate memory-related markers (e.g., TNFα, HIF1α, and mTOR) and induced NK cells to express enhanced levels of KLRG1, known as an innate memory-like marker. Our results provide support that zymosan can be an effective adjuvant to promote innate memory immune responses, providing a bridge between innate and adaptive immune cells to enhance various immune responses such as those directed against tumors.

Phosphorothioate-linked guanine/cytosine-based stem-loop oligonucleotides induce the extracellular release of mitochondrial DNA from peritoneal B1a cells

It has been previously demonstrated that phosphorothioate-linked GpC-based stem-loop oligonucleotides (GC-SL ODN) induce the release of mitochondrial DNA (mtDNA) from chronic lymphocytic leukemia (CLL) B cells. Although CLL B cells are believed to originate from CD5⁺ B cells because of their phenotypic similarities, it remains unclear whether GC-SL ODN can stimulate CD5⁺ B1 cells to secrete mtDNA. To explore this possibility, we compared the frequency of the mtDNA-producing population among peritoneal cells after GC-SL ODN treatment. We found that mtDNA-releasing cells are enriched for peritoneal CD19⁺ B cells upon GC-SL ODN challenge. Among peritoneal CD19⁺ B cells, the CD5⁺ B1a subpopulation was a primary cellular source of mtDNA secretion in GC-SL ODN-elicited immune responses. GC-SL ODN-stimulated mtDNA release by B1a cells was positively regulated by MyD88 and TRIF signaling pathways. In vivo GC-SL ODN treatment increased lipopolysaccharide-induced activation of innate immune cells such as NK cells, suggesting the immune-enhancing effects of mtDNA secretion. Furthermore, the loop size formed by GC-SL ODNs was a critical factor in inducing mtDNA release by B1a cells. Taken together, our results identified GC-SL ODN as promising biomaterials for enhancing immune responses.

CD1d-independent NK1.1+ Treg cells are IL2-inducible Foxp3+ T cells co-expressing immunosuppressive and cytotoxic molecules

Regulatory T cells (Treg) play pivotal roles in maintaining self-tolerance and preventing immunological diseases such as allergy and autoimmunity through their immunosuppressive properties. Although Treg cells are heterogeneous populations with distinct suppressive functions, expression of natural killer (NK) cell receptors (NKR) by these cells remains incompletely explored. Here we identified that a small population of Foxp3+CD4+ Treg cells in mice expresses the NK1.1 NKR. Furthermore, we found that rare NK1.1+ subpopulations among CD4+ Treg cells develop normally in the spleen but not the thymus through CD1d-independent pathways. Compared with NK1.1- conventional Treg cells, these NK1.1+ Treg cells express elevated Treg cell phenotypic hallmarks, pro-inflammatory cytokines, and NK cell-related cytolytic mediators. Our results suggest that NK1.1+ Treg cells are phenotypically hybrid cells sharing functional properties of both NK and Treg cells. Interestingly, NK1.1+ Treg cells preferentially expanded in response to recombinant IL2 stimulation in vitro, consistent with their increased IL2Rαβ expression. Moreover, DO11.10 T cell receptor transgenic NK1.1+ Treg cells were expanded in an ovalbumin antigen-specific manner. In the context of lipopolysaccharide-induced systemic inflammation, NK1.1+ Treg cells downregulated immunosuppressive molecules but upregulated TNFα production, indicating their plastic adaptation towards a more pro-inflammatory rather than regulatory phenotype. Collectively, we propose that NK1.1+ Treg cells might play a unique role in controlling inflammatory immune responses such as infection and autoimmunity.

Chromatin Regulator SRG3 Overexpression Protects against LPS/D-GalN-Induced Sepsis by Increasing IL10-Producing Macrophages and Decreasing IFNγ-Producing NK Cells in the Liver

We previously showed that ubiquitous overexpression of the chromatin remodeling factor SWItch3-related gene (SRG3) promotes M2 macrophage differentiation, resulting in anti-inflammatory responses in the experimental autoimmune encephalomyelitis model of multiple sclerosis. Since hepatic macrophages are responsible for sepsis-induced liver injury, we investigated herein the capacity of transgenic SRG3 overexpression (SRG3β-actin mice) to modulate sepsis in mice exposed to lipopolysaccharide (LPS) plus d-galactosamine (d-GalN). Our results demonstrated that ubiquitous SRG3 overexpression significantly protects mice from LPS/d-GalN-induced lethality mediated by hepatic M1 macrophages. These protective effects of SRG3 overexpression correlated with the phenotypic conversion of hepatic macrophages from an M1 toward an M2 phenotype. Furthermore, SRG3β-actin mice had decreased numbers and activation of natural killer (NK) cells but not natural killer T (NKT) cells in the liver during sepsis, indicating that SRG3 overexpression might contribute to cross-talk between NK cells and macrophages in the liver. Finally, we demonstrated that NKT cell-deficient CD1d KO/SRG3β-actin mice are protected from LPS/d-GalN-induced sepsis, indicating that NKT cells are dispensable for SRG3-mediated sepsis suppression. Taken together, our findings provide strong evidence that SRG3 overexpression may serve as a therapeutic approach to control overwhelming inflammatory diseases such as sepsis.

Coarsening kinetics of a spinodally decomposed vicinal Si(111) surface

The coarsening kinetics of the stepped-and-terrace groove structure formed on a vicinal Si(111) surface was investigated by in-situ synchrotron x-ray scattering. The time evolution of the groove period L at various temperatures below the (1 x 1)-to-(7 x 7) transition falls onto a universal curve when the annealing time is scaled by a scale factor. Distinctive stages of spinodal decomposition, coarsening, and saturation are identified in the evolution of the groove period. L increases following a power law, L approximately t;{n} with n = 1/6 and 0.29 in the initial stage and the late stage of coarsening, respectively. The initial coarsening proceeds via collective motion of step bunches while the late stage is dominated by the diffusion of individual steps.

Kinetic roughening of ion-sputtered Pd(001) surface: beyond the Kuramoto-Sivashinsky model

We investigate the kinetic roughening of Ar+ ion-sputtered Pd(001) surface both experimentally and theoretically. In situ real-time x-ray reflectivity and in situ scanning tunneling microscopy show that nanoscale adatom islands form and grow with increasing sputter time t. Surface roughness W(t) and lateral correlation length xi(t) follow the scaling laws W(t) approximately t(beta) and xi(t) approximately t(1/z) with the exponents beta approximately 0.20 and 1/z approximately 0.20, for an ion beam energy epsilon=0.5 keV, which is inconsistent with the prediction of the Kuramoto-Sivashinsky (KS) model. We thereby extend the KS model by applying the coarse-grained continuum approach of the Sigmund theory to the order of O(inverted Delta(4),h(2)), where h is the surface height, and derive a new term of the form inverted Delta(2)(inverted Delta h)(2) which plays a decisive role in describing the observed morphological evolution of the sputtered surface.

Acid-fast bacilli in sputum smears of patients with pulmonary tuberculosis. Prevalence and significance of negative smears pretreatment and positive smears post-treatment

We studied 977 patients with culture-proved pulmonary tuberculosis retrospectively to determine the frequency with which patients were sputum smear negative but culture positive (S-C+) prior to treatment, the frequency with which patients developed the smear positive but culture negative (S+C-) status during treatment, and the implication of these 2 phenomena to the success of treatment. One fourth (25.6%) of the patients were repeatedly S-C+ prior to treatment; the frequency of this phenomenon was inversely proportional to the extent of disease and the presence of cavities. Patients who were S-C+ prior to treatment, and whose organisms were drug-sensitive, had the fastest sputum culture conversion rate. Patients who were S+C+ without far-advanced cavitary disease had a significantly slower conversion rate after 1 month of treatment, and those with far-advanced cavitary disease had the slowest conversion rate. Patients with drug-resistant organisms had slower conversion rates than did their counterparts with drug-sensitive organisms, but in all but 4 of these, sputum smears and cultures ultimately converted to negative. The S+C- phenomenon was observed in 20.4% of patients; its frequency was related to the extent of disease and to treatment regimens that contained rifampin. In all patients who exhibited the S+C- phenomenon, sputum smears converted to negative with continuation of the same treatment regimen.

Atypical mycobacterial infections: a clinical study of 92 patients

Between July 1970 and December 1979, 92 patients with atypical mycobacterial infections of the lung were hospitalized 110 times at Blue Ridge Hospital (Charlottesville, Va). These patients comprised less than 3% of all patients hospitalized for active mycobacterial disease. Sixteen had Mycobacterium kansasii or group I disease, three had group II disease (two M scrofulaceum, one M szulgai), 70 had group III disease (68 M avium-intracellulare, two M xenopi), and three had M fortuitum or group IV disease. M kansasii infections comprised 23% of the total during the first five years, but only 6% during the second half of the decade. Clinical and roentgenographic findings were similar to those in patients with tuberculosis. As anticipated, most of the M kansasii organisms were sensitive to antimycobacterial drugs, and these patients generally responded well to chemotherapy. In contrast, most of the group III organisms, including one of the M xenopi, exhibited resistance to several drugs. Despite the high incidence of resistance, 59% of the patients with group III infections who were treated for at least three months in the hospital had sputum cultures converted to negative.

Paragonimus westermani: a cause of cavitary lung disease in an Indochinese refugee

A Laotian immigrant with persistent cough and hemoptysis was found to have multiple small cavities on chest roentgenogram. Ova of the lung fluke Paragonimus westermani were found in the sputum, and the patient responded to bithionol therapy. Pulmonary paragonimiasis should be considered in the differential diagnosis of cavitary lung disease in Indochinese refugees entering the United States.