bluuebunny/crossref_metadata_2025 huggingface dataset:
A temporal analysis on patient and health service delays in pulmonary tuberculosis in Portugal: inter and intra‑regional differences and in(equalities) between gender and age
Authors: Chakma Bhaswar , Gomes Dulce , Filipe Patrícia A. , Soares Patrícia , de Sousa Bruno , Nunes Carla
Published: September 2022

Background

Tuberculosis (TB) diagnosis and treatment delays increase the period of infectiousness, making TB control difficult and increasing the fatality rates. This study aimed to determine the evolution of health care service delay (time between the patient’s first contact with the health service and the diagnosis/start of treatment) and patient delay (time between onset symptoms date and the date of first contact with health services) for Pulmonary Tuberculosis (PTB) in Portugal between 2008 and 2017 across different regions, age groups and gender.

Methods

An exploratory analysis was performed, trends of both delays were studied, and 36 months forecasts were generated. We used the permutation test to test differences between groups and the Seasonal and Trend decomposition using Loess (STL) method and Autoregressive Integrated Moving Average (ARIMA) models for forecasting for both Health and Patient delays. We used data from notified PTB cases in mainland Portugal between 2008 and 2017, provided by the national surveillance system.

Results

Health delays remained relatively constant while patient delays increased. Females had significantly higher health delays in some regions. Individuals older than 64 had higher health delays than younger individuals, while patient delay for working-age individuals between 15 and 64 years old, presents higher patient delay.

Conclusions

Forecasts presage that the upward trend of the delays is unlikely to fall in the coming years. It is important to understand the evolution of the delays and predict how these will evolve. Our understanding of the delays behaviours will contribute to better health policies and resources allocation.
Consolidation radiographic morphology can be an indicator of the pathological basis and prognosis of partially solid nodules
Authors: Xie Mei , Gao Jie , Ma Xidong , Wu Chongchong , Zang Xuelei , Wang Yuanyong , Deng Hui , Yao Jie , Sun Tingting , Yu Zhaofeng , Liu Sanhong , Zhuang Guanglei , Xue Xinying , Wu Jianlin , Wang Jianxin
Published: September 2022

Background

Part-solid nodules (PSNs) have gradually shifted to defining special clinical subtypes. Commonly, the solid portions of PSNs show various radiological morphologies, of which the corresponding pathological basis and prognosis are unclear. We conducted a radiological–pathological evaluation to determine the histopathologic basis of different consolidation radiographic morphologies related to prognosis.

Materials and methods

A cohort of 275 patients with a surgical pathological diagnosis of lung adenocarcinoma were enrolled. Preoperative computed tomography (CT) images of the PSNs were recorded and assessed. A panel of 103 patients with complete pathological specimens was selected to examine the radiological–pathological associations, and follow-up was performed to identify the prognosis.

Results

Of the 275 patients, punctate consolidation was observed radiologically in 43/275 (15.7%), stripe consolidation in 68/275 (24.7%), and irregular consolidation in 164/275 (59.6%) patients. The radiological morphology of the solid components was significantly associated with the histopathological subtypes (P < 0.001). Visual punctate solid components on CT correlated with tertiary lymphoid structures, stripe solid components on CT correlated with fibrotic scar, and irregular solid components on CT correlated with invasion. PSNs with regular consolidation had a better prognosis than those with irregular consolidation.

Conclusion

Radiological morphology of solid components in PSNs can indicate the pathological basis and is valuable for prognosis. In particular, irregular solid components in PSNs usually indicate serious invasive growth, which should be taken with caution during assessment.
Dapagliflozin reduces the vulnerability of rats with pulmonary arterial hypertension-induced right heart failure to ventricular arrhythmia by restoring calcium handling
Authors: Wu Jinchun , Liu Tao , Shi Shaobo , Fan Zhixing , Hiram Roddy , Xiong Feng , Cui Bo , Su Xiaoling , Chang Rong , Zhang Wei , Yan Min , Tang Yanhong , Huang He , Wu Gang , Huang Congxin
Published: September 2022

Background

Malignant ventricular arrhythmia (VA) is a major contributor to sudden cardiac death (SCD) in patients with pulmonary arterial hypertension (PAH)-induced right heart failure (RHF). Recently, dapagliflozin (DAPA), a sodium/glucose cotransporter-2 inhibitor (SGLT2i), has been found to exhibit cardioprotective effects in patients with left ventricular systolic dysfunction. In this study, we examined the effects of DAPA on VA vulnerability in a rat model of PAH-induced RHF.

Methods

Rats randomly received monocrotaline (MCT, 60 mg/kg) or vehicle via a single intraperitoneal injection. A day later, MCT-injected rats were randomly treated with placebo, low-dose DAPA (1 mg/kg/day), or high-dose (3 mg/kg/day) DAPA orally for 35 days. Echocardiographic analysis, haemodynamic experiments, and histological assessments were subsequently performed to confirm the presence of PAH-induced RHF. Right ventricle (RV) expression of calcium (Ca2+) handling proteins were detected via Western blotting. RV expression of connexin 43 (Cx43) was determined via immunohistochemical staining. An optical mapping study was performed to assess the electrophysiological characteristics in isolated hearts. Cellular Ca2+ imaging from RV cardiomyocytes (RVCMs) was recorded using Fura-2 AM or Fluo-4 AM.

Results

High-dose DAPA treatment attenuated RV structural remodelling, improved RV function, alleviated Cx43 remodelling, increased the conduction velocity, restored the expression of key Ca2+ handling proteins, increased the threshold for Ca2+ and action potential duration (APD) alternans, decreased susceptibility to spatially discordant APD alternans and spontaneous Ca2+ events, promoted cellular Ca2+ handling, and reduced VA vulnerability in PAH-induced RHF rats. Low-dose DAPA treatment also showed antiarrhythmic effects in hearts with PAH-induced RHF, although with a lower level of efficacy.

Conclusion

DAPA administration reduced VA vulnerability in rats with PAH-induced RHF by improving RVCM Ca2+ handling.
Epidermal nevus syndrome with the mutation of PTCH1 gene and cerebral infarction: a case report and review of the literature
Authors: Deng QingQing , Li Yan , Liu ZhanLi , Zhou JieLin , Weng LingWei
Published: September 2022

Background

Epidermal nevus syndrome is a group of congenital neuroectodermal and/or mesodermal disorders characterized by the epidermal nevi in common association with cerebral, eye, skeletal, cardiovascular, and renal abnormalities. Epidermal nevus syndrome is a rare syndrome, and epidermal nevus syndrome with the mutation of PTCH1 gene and cerebral infarction is even rarer and has not been reported to the best of our knowledge.

Case presentation

We report the case of a 10-month-old Chinese female patient who presented to our pediatric neurologic department, University of Wenzhou medical teaching Hospital, Hangzhou. She has mobility disorders on the right limbs and recurrent seizures. She had congenital disorder accompanied by brownish-black and verrucose plaques on the right side of the face as well as extensive brownish-black plaques and brown nevi on the right side of the trunk and the right arm. Epidermal nevus syndrome was diagnosed on the basis of her symptoms. Somatic sebaceous nevi and hypoplastic defects of skin, cerebra, eyes, skeleton, and cardiovascular and renal system were observed. However, in addition to the typical clinical characteristics, the patient also has a mutation (c.109G > T) in PTCH1 gene and cerebral infarction. We present a novel case report and literature review.

Conclusion

To our knowledge, epidermal nevus syndrome with a mutation of PTCH1 gene and cerebral infarction has not been reported previously. This case report may contribute to characterizing the phenotype of epidermal nevus syndrome, help clinicians be aware of the association of this condition with PTCH1 gene and cerebral infarction, raise clinical suspicion, and improve early therapy.
Proteasome-mediated regulation of interleukin-1β turnover and export in human monocytes
Authors: Moors Marlena A , Mizel Steven B
Published: September 2022

Interleukin-1β is a secreted protein that accumulates in the cytosol as an inactive precursor (pIL-1β) before processing and release of biologically active protein. To understand the impact of this property on IL-1β production, we examined the intracellular stability of pIL-1β in lipopolysaccharide (LPS)-stimulated human monocytes. Precursor IL-1β was degraded with a relatively short half-life of 2.5 h in the promonocytic cell line, THP-1, and in primary monocytes. MG132 (carbobenzoxyl-leucinyl-leucinyl-leucinal) stabilized pIL-1β levels in THP-1 cells, suggesting that degradation was proteasome-mediated, but this inhibitor was toxic for primary monocytes, causing release of pIL-1β as well as the cytoplasmic enzyme, lactate dehydrogenase (LDH) into supernatants. In contrast, clasto-lactacystin β-lactone, a specific inhibitor of the proteasome, caused a dose-dependent stabilization of intracellular pIL-1β, and this led to a corresponding increase in mIL-1β and pIL-1β but not LDH release into culture supernatants. Therefore, by regulating intracellular levels of precursor IL-1β, the proteasome plays an important and previously unrecognized role in controlling the amount of biologically active IL-1β that is exported by activated monocytes.
The colony-stimulating factors and collagen-induced arthritis: exacerbation of disease by M-CSF and G-CSF and requirement for endogenous M-CSF
Authors: Campbell Ian K , Rich Melissa J , Bischof Robert J , Hamilton John A
Published: September 2022

There is increasing evidence that the colony-stimulating factors (CSFs) may play a part in chronic inflammatory autoimmune diseases, such as rheumatoid arthritis (RA). We examined the involvement of macrophage CSF (M-CSF or CSF-1) and granulocyte CSF (G-CSF) in collagen-induced arthritis (CIA), a murine model of RA. Daily injections of M-CSF or G-CSF, 20–24 days postprimary immunization with type II collagen, exacerbated disease symptoms in suboptimally immunized DBA/1 mice. Support for the involvement of endogenous M-CSF in CIA was obtained by studies in which neutralizing monoclonal antibody reduced the severity of established CIA and also by studies showing the resistance of M-CSF-deficient op/op mice to CIA induction. These studies show that M-CSF and G-CSF can be proinflammatory in CIA and provide evidence that macrophage- and granulocyte-lineage cells can exacerbate CIA. Our results also show that M-CSF-dependent cells are essential for CIA development, suggesting M-CSF may be a suitable target for therapeutic intervention in RA.
Adhesion of human lung mast cells to bronchial epithelium: evidence for a novel carbohydrate-mediated mechanism
Authors: Sanmugalingam Devika , Wardlaw Andrew J , Bradding Peter
Published: September 2022

Mast cells contribute to the pathophysiology of asthma through their immunomediator-secretory activity in response to both immunological and nonimmunological stimuli, and infiltrate the bronchial epithelium in this disease. We hypothesized that human lung mast cells (HLMC) localize to the bronchial epithelium via a specific cell-cell adhesion mechanism. We investigated the adhesion of HLMC to primary bronchial epithelial cells and the bronchial epithelial cell line BEAS-2B. HLMC adhered avidly to both primary cultures of bronchial epithelial cells and BEAS-2B cells (mean adhesion 68.4 and 60.1%, respectively) compared with eosinophil adhesion to BEAS-2B (mean adhesion 10.3%). HLMC adhesion did not alter after epithelial activation with cytokines, did not require Ca2+, and was not integrin-mediated. IgE-dependent activation of HLMC produced an approximately 40% inhibition of adhesion. There was significant attenuation of adhesion after incubation of HLMC with pronase, β-galactosidase, and endo-α-N-acetylgalactosaminidase, indicating that HLMC adhere to bronchial epithelial cells via galactose-bearing carbohydrates expressed on a cell-surface peptide(s).
Sulfatide binding and activation of leukocytes through an L-selectin-independent pathway
Authors: Ding Ziqiang , Kawashima Hiroto , Miyasaka Masayuki
Published: September 2022

Sulfatide has been reported to activate leukocytes through L-selectin. Here we provide evidence that sulfatide binds to and activates leukocytes through both L-selectin-dependent and -independent pathways. Rat leukocytes of various sources shed surface L-selectin after phorbol myristate acetate (PMA) treatment, however, these cells retained the ability to bind sulfatide. In addition, sulfatide also bound to an L-selectin-negative cell line EL-4, and the binding was up-regulated by PMA. Sulfatide induced aggregation of L-selectin-positive lymphocytes, which was highly dependent on divalent cations, protein tyrosine kinases (PTK), and protein kinase C (PKC), but was independent of β1 and β2 integrins. In contrast, sulfatide-induced EL-4 cell aggregation required an LFA-1/ICAM-1 adhesion pathway but not PTK and PKC. A sulfatide receptor of 65 kDa was isolated from EL-4 cells. Taken together, this study suggests that sulfatide can bind to and activate leukocytes through an L-selectin-independent molecule and triggers signal transduction pathways different from those induced by L-selectin activation.
Autologous dendritic cells or cells expressing both B7-1 and MUC1 can rescue tumor-specific cytotoxic T lymphocytes from MUC1-mediated apoptotic cell death
Authors: Kontani Keiichi , Taguchi Osamu , Narita Tatsuhiko , Hiraiwa Nozomu , Sawai Satoru , Hanaoka Jun , Ichinose Masutaro , Tezuka Noriaki , Inoue Shuhei , Fujino Shozo , Kannagi Reiji
Published: September 2022

We attempted to induce MUC1-specific cytotoxic T lymphocytes (CTLs) by mixed-lymphocyte tumor cell culture (MLTC) using two allogeneic MUC1-positive cancer cell lines, T-47D and MCF7. The induced CTLs exhibited MUC1-specific cytotoxicity 16 days after the initial stimulation. However, these CTLs underwent apoptotic death within 16 days. To examine whether the B7-1 molecule is required for the expansion of the responder cells, a B7-1(+)/MUC1(-) cell line was transfected with MUC1 cDNA, and the resulting transfectant was employed as a stimulator in an autologous MLTC. The CTLs exhibited MUC1 specificity but also continued to propagate. In parallel, autologous dendritic cells (DCs) were added to an MLTC containing peripheral blood lymphocytes (PBLs) and the allogeneic MUC1-positive stimulators. The CTLs demonstrated MUC1 specificity and their number increased. This suggests that the B7-1 molecule is required for rescuing CTLs from MUC1-mediated apoptotic death, but not for the induction of MUC1-specific responsiveness. This strategy to obtain the CTLs efficiently may be useful for adoptive immunotherapy against cancer.
Combined inhibition of indoleamine 2,3-dioxygenase and nitric oxide synthase modulates neurotoxin release by interferon-γ-activated macrophages
Authors: Chiarugi Alberto , Sbarba Persio Dello , Paccagnini Alessandro , Donnini Sandra , Filippi Sandra , Moroni Flavio
Published: September 2022

We evaluated the synthesis of nitric oxide (NO) and of the neurotoxic kynurenine metabolites 3OH-kynurenine and quinolinic acid (QUIN) in interferon-γ (IFN-γ)-activated macrophages of the murine BAC1.2F5 cell line with the aim of investigating the roles of mononuclear phagocytes in inflammatory neurological disorders. IFN-γ induced indoleamine 2,3-dioxygenase (IDO) and NO synthase (NOS) and increased the synthesis of 3OH-kynurenine, QUIN, and NO that accumulated in the incubation medium where they reached neurotoxic levels. Macrophage exposure to norharmane, an IDO inhibitor, resulted in a decreased formation of not only the kynurenine metabolites but also NO. The inhibition of NO synthesis could not be ascribed to reduced NADPH availability or decreased NOS induction. Norharmane inhibited NOS activity also in coronary vascular endothelial cells and in isolated aortic rings. Our findings suggest that activated macrophages release large amounts of neurotoxic molecules and that norharmane may represent a prototype compound to study macrophage involvement in inflammatory brain damage.
TNF-α-mediated neutrophil apoptosis involves Ly-GDI, a Rho GTPase regulator
Authors: Kettritz Ralph , Xu Ya-Xin , Faass Bettina , Klein Jon B , Müller Eva C , Otto Albrecht , Busjahn Andreas , Luft Friedrich C , Haller Hermann
Published: September 2022

We investigated intracellular signaling events involved in fibronectin-accelerated TNF-α-mediated PMN apoptosis by means of 2-D gel electrophoresis and western blotting. Proteins were sequenced with electrospray ionization mass spectrometry. Apoptosis was quantitated by flow cytometry. We detected a cluster of acidic, high molecular-weight proteins that were only tyrosine phosphorylated when TNF-α-treated PMN interacted with fibronectin. Sequence analysis revealed that one of these proteins was Ly-GDI, a regulator of Rho GTPases. Fibronectin increased the TNF-α-induced Ly-GDI cleavage, yielding a 23-kD fragment. At 8 h, intact Ly-GDI was decreased to 33% on fibronectin, compared with 69% on PolyHema (P<0.05). Inhibition of tyrosine phosphorylation prevented phosphorylation of Ly-GDI, fibronectin-accelerated Ly-GDI cleavage, and fibronectin-accelerated apoptosis in TNF-α-treated PMN. We found that Ly-GDI cleavage was dependent on caspase-3 activation and that caspase-3 inhibition decreased apoptosis. We conclude that tyrosine phosphorylation of Ly-GDI, followed by increased caspase-3-mediated Ly-GDI cleavage, is a signaling event associated with accelerated TNF-α-mediated apoptosis on fibronectin.
The level of HIV infection of macrophages is determined by interaction of viral and host cell genotypes
Authors: Cunningham A L , Li S , Juarez J , Lynch G , Alali M , Naif H
Published: September 2022

The outcome of HIV infection in vivo and in vitro depends on the interaction of viral and cellular genotypes. Analysis of infection of blood monocyte-derived macrophages by primary HIV strains shows that approximately one-third of 32 isolates was consistently high-replicating, one-third was consistently low-replicating, and one-third was dependent on the donor of the macrophages (i.e., variable). HIV isolates from patients with AIDS showed enhanced replication within macrophages and predominant use of CCR5 for entry, although 13% did use CXCR4. Tissue isolates from brain and CSF showed an enhanced ability to infect 1-day-old monocytes compared with blood isolates from patients with AIDS. The ability of primary isolates to infect neonatal or adult monocytes maturing into macrophages or placental macrophages correlated directly with the extent of CCR5 expression. Studies of macrophages from pairs of identical twins and unrelated donors showed genetic control over CCR5 expression, which was independent of the CCR5▵32 genotype. Furthermore, these studies showed a marked host-cell genetic effect on the variable primary HIV strains. Although CCR5 was essential for the entry of most primary isolates, it was not the essential “bottleneck” determining productivity of infection. The location of this bottleneck in the HIV replication cycle differs according to viral strain and host-cell donor, but it was exerted before the stage of reverse transcription in 80–90% of cases. Such host-cell genetic factors may affect viral load in vivo where macrophages are the predominant target cells.
The emerging role of CD40 ligand in HIV infection
Authors: Kornbluth Richard S
Published: September 2022

CD40 ligand (also called CD40L, CD154, or TNFSF5) is a membrane protein expressed mainly by activated CD4+ T cells, which interacts with its receptor, CD40, on a variety of cells. The crucial importance of the CD40L-CD40 system for many immune responses has been extensively described. This review focuses on the multiple roles that this system may play in HIV infection. In early HIV infection, CD40L expression contributes to the immunological control of viral replication by inducing HIV-suppressive chemokines and supporting the production of anti-HIV antibodies and cytotoxic T cells. However, by activating antigen-presenting cells, such as dendritic cells and macrophages, CD40L can also lead to increased CD4+ T cell activation, which promotes the replication of HIV in these lymphocytes. Later, with the development of AIDS, CD40L-expressing CD4+ T cells become selectively depleted, perhaps as a result of a gp120-induced signal through CD4 that down-regulates CD40L expression. This acquired CD40L deficiency may explain the similarity between the types of opportunistic infections that occur in AIDS and in congenital CD40L deficiency. Vaccines or other strategies that promote the growth of CD4+ T cells capable of expressing CD40L may help to sustain host immunity against HIV and prevent AIDS-defining opportunistic infections.
Macrophage-derived chemokine (MDC)
Authors: Mantovani Alberto , Gray Patrick A , Van Damme Jo , Sozzani Silvano
Published: September 2022

Macrophage-derived chemokine (MDC) is a CC chemokine paradigmatic of emerging aspects of chemokine immunobiology. It is constitutively expressed, yet microbial products and cytokines regulate its expression with divergent effects of type II (IL-4 and IL-13) and type I (interferon) cytokines. Processing of the mature protein by dipeptidyl peptidase IV/CD26 provides a further level of regulation. It acts on diverse cellular targets including dendritic cells (DC), NK cells, and T cell subsets. Among these, MDC is a potent attractant for CCR4 expressing polarized Th2 and Tc2 cells, and evidence is consistent with a role of this chemokine as an amplification loop of polarized type II responses. Emerging indications on the involvement of MDC in diverse pathologies, ranging from allergic reactions to HIV infection and neoplasia, are discussed.
Leptin in the regulation of immunity, inflammation, and hematopoiesis
Authors: Fantuzzi Giamila , Faggioni Raffaella
Published: September 2022

Leptin, the product of the ob gene, is a pleiotropic molecule that regulates food intake as well as metabolic and endocrine functions. Leptin also plays a regulatory role in immunity, inflammation, and hematopoiesis. Alterations in immune and inflammatory responses are present in leptin- or leptin-receptor-deficient animals, as well as during starvation and malnutrition, two conditions characterized by low levels of circulating leptin. Both leptin and its receptor share structural and functional similarities with the interleukin-6 family of cytokines. Leptin exerts proliferative and anti-apoptotic activities in a variety of cell types, including T lymphocytes, leukemia cells, and hematopoietic progenitors. Leptin also affects cytokine production, the activation of monocytes/macrophages, wound healing, angiogenesis, and hematopoiesis. Moreover, leptin production is acutely increased during infection and inflammation. This review focuses on the role of leptin in the modulation of the innate immune response, inflammation, and hematopoiesis.
The protective effect of IFN-γ in experimental autoimmune diseases: a central role of mycobacterial adjuvant-induced myelopoiesis
Authors: Matthys Patrick , Vermeire Kurt , Heremans Hubertine , Billiau Alfons
Published: September 2022

The study of animal models for organ-specific autoimmune disease contributes to our understanding of human diseases such as multiple sclerosis and rheumatoid arthritis. Although experimental autoimmune diseases develop spontaneously in certain strains of mice, others need to be induced by administration of organ-specific autoantigen, often together with complete Freund’s adjuvant (CFA), containing heat-killed mycobacteria. In the two types of models, the role of endogenous interferon-γ (IFN-γ) has extensively been investigated by using neutralizing anti-IFN-γ antibodies and by employing mice genetically deficient in IFN-γ or its receptor. In these studies disease-promoting as well as disease-protective roles of endogenous IFN-γ have been described. Remarkably, in most models that rely on the use of CFA, there is abundant evidence for a protective role. Here, we review evidence that this role derives from an inhibitory effect of IFN-γ on myelopoiesis elicited by the killed mycobacteria. These findings explain the bimodal role of IFN-γ in different models of autoimmune disease and raise questions regarding the clinical relevance of these models.
Impaired splenic erythropoiesis in phlebotomized mice injected with CL2MDP-liposome: an experimental model for studying the role of stromal macrophages in erythropoiesis
Authors: Sadahira Yoshito , Yasuda Tatsuji , Yoshino Tadashi , Manabe Toshiaki , Takeishi Toshiyuki , Kobayashi Yoshiaki , Ebe Yusuke , Naito Makoto
Published: September 2022

Erythropoiesis occurs in the presence of erythropoietin (EPO) without macrophages in vitro. In hematopoietic tissues, however, erythroid cells associate closely with stromal macrophages, forming erythroblastic islands via interactions with adhesion molecules. To elucidate the role of macrophages in erythropoiesis, we selectively abrogated stromal macrophages of splenic red pulp of phlebotomized mice by injection with dichloromethylene diphosphonate encapsulated in multilamellar liposomes (CL2MDP-liposome). In the spleen, no erythropoietic activity occurred until 5 days after the treatment. Colony assay revealed that the erythropoiesis was suppressed at the level of CFU-E. The splenic erythropoietic activity gradually developed from day 6 after the treatment, when F4/80+ macrophages began to appear in the red pulp. EPO mRNA was expressed in kidney but not in liver or spleen of phlebotomized mice injected with CL2MDP-liposome, and the serum EPO concentration in these mice was higher than that in phlebotomized mice. These findings suggest that abrogation of stromal macrophages by injection with CL2MDP-liposome impairs the splenic microenvironment for erythropoiesis induced by hypoxic stress, and this may be an excellent experimental model for further characterization of the in vivo role of splenic macrophages in erythropoiesis.
Migration of dermal cells expressing a macrophage C-type lectin during the sensitization phase of delayed-type hypersensitivity
Authors: Chun Kyung-hee , Imai Yasuyuki , Higashi Nobuaki , Irimura Tatsuro
Published: September 2022

Dermal cells expressing a macrophage C-type lectin (mMGL) were previously suggested to migrate to regional lymph nodes during the sensitization phase of delayed-type hypersensitivity (DTH). The migration seemed to be induced by the solvent used to dissolve the antigen, and the DTH response was significantly enhanced by the migration. In this study, immunohistochemical analysis of skin after epicutaneous application of one of such solvents, a mixture of acetone and dibutylphthalate (AD), revealed a transient decrease in the number of mMGL-positive cells in the dermis. A similar decrease in this cell population was also observed in an ex vivo assay with skin explants excised from AD-treated sites. Conditioned medium from organ culture of AD-treated skin induced a similar decrease of mMGL-positive cells in untreated dermis, indicating the involvement of soluble factors. mMGL-positive cells seemed to represent a unique subpopulation of F4/80-positive dermal cells.
Altered membrane trafficking in activated bone marrow-derived macrophages
Authors: Tsang Albert W , Oestergaard Kirsten , Myers Jesse T , Swanson Joel A
Published: September 2022

Activation of macrophages with interferon-γ (IFN-γ) and lipopolysaccharide (LPS) leads to increased intracellular resistance to microbes and increased major histocompatibility complex class II-restricted antigen presentation, processes that both use the vacuolar compartment. Despite the requirement of the macrophage vacuolar compartment for microbicidal activities and antigen processing, the rates of endocytosis and membrane trafficking in activated macrophages are not clearly defined. In this study, vacuolar compartment dynamics were analyzed in murine bone marrow-derived macrophages activated with LPS and/or IFN-γ, conditions that increased macrophage nitric oxide production and resistance to infection by Listeria monocytogenes. Relative to nonactivated cells, activated macrophages showed diminished rates of fluid-phase pinocytosis and phagocytosis and delayed progression of macropinosomes and phagosomes to late endosomes and lysosomes. In contrast to the slowing of membrane trafficking, rates of macropinosome acidification were similar between activated and nonactivated cells. One consequence of this slowed membrane trafficking in activated macrophages was a prolonged exposure of incoming molecules to an acidic nonlysosomal compartment, a condition which may facilitate microbicidal chemistries or antigen processing.
Engagement of β2 integrins induces surface expression of β1 integrin receptors in human neutrophils
Authors: Werr Joachim , Eriksson Einar E , Hedqvist Per , Lindbom Lennart
Published: September 2022

Induction of β1 integrin (CD49/CD29) expression in polymorphonuclear leukocytes (PMN) has been shown to be associated with transendothelial migration recently. Yet, β1 integrin expression is relatively insensitive to cell activation with soluble agonists, such as N-formyl-methionyl-leucyl-phenylalanine (fMLP). We hypothesized that β2 integrins (CD11/CD18), critically involved in PMN adhesion and extravasation, may play a role in regulating β1 integrin expression in PMN. Antibody cross-linking of CD18, mimicking adhesion-dependent engagement of β2 integrins, resulted in rapid, tyrosine kinase-dependent upregulation of β1 integrins. This response was potentiated by simultaneous chemoattractant (fMLP) stimulation of PMN. Moreover, upregulation of β1 integrins evoked by CD18 cross-linking was found to support adhesion of fMLP-stimulated PMN to matrix proteins and also was critical for the ability of PMN to migrate in collagen gels in response to a gradient of fMLP. Taken together, these data demonstrate that engagement of β2 integrins in human PMN induces β1 integrin expression in these cells of significance for their migration in the extravascular tissue. Thus, β2 integrins may serve the function to regulate PMN locomotion in extravascular tissue via receptor crosstalk with β1 integrins.
Differential expression of the chemokine receptors by the Th1- and Th2-type effect or populations within circulating CD4+ T cells
Authors: Yamamoto Junko , Adachi Yuichi , Onoue Yoichi , Adachi Yoko S , Okabe Yoshie , Itazawa Toshiko , Toyoda Masahiko , Seki Taisuke , Morohashi Masaaki , Matsushima Kouji , Miyawaki Toshio
Published: September 2022

The in vitro studies have proposed that human Th1 cells favor expression of CXCR3 or CCR5, whereas Th2 cells favor CCR3 and CCR4. In this study, the in vivo relevance of expression of these chemokine receptors on Th cells was investigated in patients with atopic dermatitis (AD) as the Th2-dominated disorder and nonatopic normal individuals. Flow-cytometric analysis using monoclonal antibodies against CXCR3, CCR5, CCR3, and CCR4 disclosed that a substantial proportion of memory (CD45RO+) CD4+ T cells in the blood of AD and normal patients expressed CXCR3, CCR5, or CCR4, but expression of CCR3 on these cells was negligible. Stimulation studies combined with intracellular cytokine staining revealed that the cells capable of producing Th2 cytokines, such as interleukin-4 (IL-4), IL-5, and IL-13, were restricted to the CCR4-expressing population within memory CD4+ T cells. Concerning Th1 cytokine production, interferon-γ (IFN-γ)-producing cells resided exclusively in CXCR3-expressing memory CD4+ T cells, although IFN-γ production was found in both memory CD4+ T cells with and without CCR5 expression. We observed that CCR4-expressing memory CD4+ T cells in the blood were more increased in AD patients as compared with normal patients, whereas CXCR3-expressing memory CD4+ T cells were present in a lower frequency in AD than seen in normal patients. These results suggest that CXCR3 and CCR4, but not CCR5 or CCR3, appear to serve as the useful markers for identification of circulating Th1 and Th2 effector populations.
Linomide abolishes leukocyte adhesion and extravascular recruitment induced by tumor necrosis factor αin vivo
Authors: Zhang Xiao Wei , Hedlund Gunnar , Borgström Per , Arfors Karl E , Thorlacius Henrik
Published: September 2022

The immunomodulator Linomide (roquinimex) ameliorates the development of numerous inflammatory and immunological diseases, including sepsis, arthritis, and encephalomyelitis. However, the mechanism underlying this protective effect of Linomide remains unclear. In this study, we wanted to evaluate the effect of Linomide treatment on the different steps in the extravasation process of leukocytes stimulated by tumor necrosis factor α (TNF-α) in vivo. For this purpose, we used intravital microscopy in the mouse cremaster muscle microcirculation. We found that pretreatment with Linomide dose-dependently (3–300 mg/kg) reduced TNF-α-induced leukocyte adhesion and tissue recruitment. Notably, at 300 mg/kg of Linomide, the leukocyte response to TNF-α was nearly abolished, i.e. leukocyte adhesion was decreased by 83% and recruitment by 86%. In fact, the anti-inflammatory effect of this dose of Linomide corresponded in magnitude to the potency of 10 mg/kg of dexamethasone. Moreover, administration of Linomide did not alter the systemic leukocyte counts. On the other hand, 1–10 mg/kg of dexamethasone decreased the circulating number of mononuclear leukocytes by 77%. Taken together, our novel findings demonstrate that Linomide is a potent inhibitor of leukocyte adhesion and recruitment in cytokine-activated tissues. These data may help explain the documented protection provided by Linomide in inflammatory diseases characterized by cytokine activation and leukocyte accumulation.
αMβ2 (CD11b/CD18, Mac-1) integrin activation by a unique monoclonal antibody to αM I domain that is divalent cation-sensitive
Authors: Orchekowski Randal P , Plescia Janet , Altieri Dario C , Bajt Mary Lynn
Published: September 2022

The β2 (CD18) leukocyte integrins play a key role in normal and inflammatory immune responses. In resting leukocytes, these receptors do not bind ligands. However, when leukocytes are exposed to an appropriate agonist, high-affinity ligand binding is achieved, presumably as a result of conformational changes in the integrin. In this study, we describe a novel monoclonal antibody, mAb 6C1, directed against the αM subunit, which directly induces adhesion of αMβ2-transfected CHO cells to fibrinogen, ICAM-1, and iC3b. Induction of binding could also be accomplished by monovalent Fab fragments of mAb 6C1 at concentrations similar to that observed with intact IgG, demonstrating stimulation of adhesion was not because of receptor cross-linking at the cell surface. The binding of mAb 6C1 induces conformational changes in the receptor, as evidenced by the expression of an “activation reporter” epitope recognized by mAb 24. The binding of mAb 6C1 is modulated by divalent cations. Mn2+ promoted high levels of 6C1 binding, and Mg2+ supported low levels of binding, however Ca2+ failed to support binding. A unique distinction of mAb 6C1 is localization of its epitope to the αM I domain. The αM I domain is essential for ligand binding, can directly bind divalent cations, and participates in the regulation of αMβ2 ligand-binding affinity. Thus, these studies have identified a novel αM I domain activation epitope of αMβ2 and support the idea that the I domain modulates the activational state of the β2 integrins.
Fas activation reduces neutrophil adhesion to endothelial cells
Authors: Greenstein Stephanie , Barnard Joseph , Zhou Kairong , Fong Miranda , Hendey Bill
Published: September 2022

Polymorphonuclear neutrophils (PMN) express apoptotic markers and lose effector functions including adhesion, chemotaxis, and phagocytosis when cultured overnight. Although the loss of function correlates with apoptosis, it is not clear if functions are lost before an early marker of apoptosis, the display of phosphatidylserine (PS), targets PMN for removal by phagocytic cells. To address this question, freshly isolated PMN were treated with Fas-activating antibodies to induce apoptosis rapidly. Early markers of apoptosis and PMA-stimulated adhesion to endothelial cells were measured. After 1 h of Fas exposure, only 16% PMN had externalized PS. In contrast, Fas activation reduced PMA-stimulated adhesion between 68 and 27% depending on PMA concentration. The loss of adhesion was accompanied by a reduction in β2 integrin expression and receptor clustering. These results indicate that the Fas-induced loss of adhesion may precede PS externalization and could limit participation in the inflammatory response before PS externalization targets PMN for removal.
Morphine enhances interleukin-12 and the production of other pro-inflammatory cytokines in mouse peritoneal macrophages
Authors: Peng Xiaohui , Mosser David M , Adler Martin W , Rogers Thomas J , Meissler Joseph J , Eisenstein Toby K
Published: September 2022

In this study we investigated the capacity of morphine to modulate expression of cytokines in peritoneal macrophages. Mice were implanted subcutaneously with a 75-mg morphine slow-release pellet, and 48 h later resident peritoneal macrophages were harvested. Control groups received placebo pellets, naltrexone pellets, or morphine plus naltrexone pellets. Adherent cells were stimulated with lipopolysaccharide (LPS: 10 μg/mL) plus interferon-γ (IFN-γ: 100 units/mL) to induce cytokine production. After 24 h RNA was extracted for analysis of cytokine mRNA levels by reverse transcriptase-polymerase chain reaction, or supernatants were collected after 48 h for determination of cytokine production by enzyme-linked immunosorbent assay (ELISA). Morphine enhanced mRNA expression of interleukin (IL)-12 p40 and tumor necrosis factor α (TNF-α) compared with controls, whereas IL-10 levels were unchanged by drug treatment. ELISA data showed that both IL-12 p40 and p70 were increased by morphine. The enhancement of IL-12 at both the mRNA and protein levels was antagonized by naltrexone, indicating that the modulation of this cytokine by morphine is via a classic opioid receptor. These results are particularly interesting in light of our previous observation that 48 h after morphine pellet implantation, the peritoneal cavity is colonized with gram-negative and other enteric bacteria. The enhancement of IL-12 by morphine might be related to morphine-induced sepsis.
Identification of the Ly49L protein: evidence for activating counterparts to inhibitory Ly49 proteins
Authors: Makrigiannis Andrew P , Etzler Jessica , Winkler-Pickett Robin , Mason Anna , Ortaldo John R , Anderson Stephen K
Published: September 2022

Previous studies have indicated that NK cells from different strains of inbred mice may express distinct Ly49 repertoires. Screening of NK cells from the CBA/J mouse for inhibitory and activating Ly49s revealed a novel DAP12-associated receptor that was immunoprecipitated with the Ly49G-specific mAb 4D11. Degenerate primers were designed to amplify and clone Ly49 cDNAs from CBA/J NK cells. A novel activating Ly49 cDNA was identified, which bears strong homology to the partially sequencedLy49l gene found in C57BL/6 mice. Transfection ofLy49l into a DAP12+ cell line and subsequent immunoprecipitation experiments showed that Ly49L is likely the activating Ly49 detected by the 4D11 antibody in CBA/J NK cells. Antibody-mediated cross-linking of Ly49L induced DAP12 phosphorylation, providing evidence that Ly49L is a functional activating receptor. Comparison of the extracellular domains of Ly49 family members indicates that all known activating members have an inhibitory counterpart with a highly related extracellular region.
Mono Mac 1: a new in vitro model system to study HIV-1 infection in human cells of the mononuclear phagocyte series
Authors: Genois Nicolas , Robichaud Gilles A , Tremblay Michel J
Published: September 2022

Throughout the years, most researchers have used continuous cell lines as in vitro models to evaluate the immunopathogenesis of human immunodeficiency virus type-1 (HIV-1) infection. Unfortunately, the most commonly used monocytoid malignant cells have not been shown to adequately mimic primary human monocyte-derived macrophages, at least with respect to HIV-1 infection. The Mono Mac 1 cell line has been defined as a model system for studying biochemical, immunological, and genetic functions of human cells of the monocyte/macrophage lineage. In this study, we have investigated whether Mono Mac 1 represents an in vitro culture system for HIV-1 infection. Flow cytometric analyses revealed that Mono Mac 1 are positive for the HIV-1 primary receptor (CD4), as well as for the coreceptors (CXCR4, CCR5, and CCR3). Infectivity experiments conducted with recombinant luciferase-encoding and fully infectious viruses demonstrated that Mono Mac 1 can support a highly productive infection with both macrophage- and dual-tropic isolates of HIV-1. Furthermore, differentiation of such cells led to a marked increase in virus production. Data from semiquantitative polymerase chain reaction analysis and mobility shift assays indicated that enhanced virus production in differentiated Mono Mac 1 cells was most likely related to an increase in nuclear translocation of NF-κB. Mono Mac 1 can thus be considered as a human monocytoid cell line representing a proper in vitro system for studying the complex interactions between HIV-1 and cells of the monocyte/macrophage lineage.
Streptolysin O-permeabilized granulocytes shed L-selectin concomitantly with ceramide generation via neutral sphingomyelinase
Authors: Walev Iwan , Tappe Dennis , Gulbins Erich , Bhakdi Sucharit
Published: September 2022

Cleavage of membrane-associated L-selectin regulates leukocyte rolling on vascular endothelium at sites of inflammation. We report that rapid and massive shedding of L-selectin occurs from granulocytes attacked by the pore-forming bacterial toxin streptolysin O (SLO). Shedding was not induced by an SLO mutant that retained binding capacity but lacked pore-forming activity. Cells permeabilized with SLO exhibited a 1.5-fold increase in the activity of neutral sphingomyelinase, which was accompanied by increased ceramide formation. L-selectin cleavage was inducible by treatment of cells with bacterial sphingomyelinase, and also through exogenous application of a cell-permeable ceramide analog. Our data identify a novel path to the shedding process and show that activation of neutral sphingomyelinase with the generation of ceramide is an important event underlying enhanced sheddase function in cells permeabilized by a pore-forming toxin.
Role of IL-12 in macrophage activation during intracellular infection: IL-12 and mycobacteria synergistically release TNF-α and nitric oxide from macrophages via IFN-γ induction
Authors: Xing Zhou , Zganiacz Anna , Santosuosso Micheal
Published: September 2022

IL-12 is believed to play an important role in cell-mediated immunity against intracellular infection primarily by acting on T and NK cells. Recent evidence has suggested, however, that IL-12 has broader cellular targets than previously thought. In this study, we examined the role of IL-12 in macrophage TNF-α and nitric oxide (NO) release by using anin vitro model of intracellular infection. IL-12 alone released relatively little TNF-α and NO, whereas live mycobacteria alone released TNF-α markedly but little NO from murine alveolar macrophages. However, IL-12 and mycobacteria together enhanced TNF-α and NO release synergistically. Because IL-12 and mycobacteria also released IFN-γ from macrophages synergistically, and exogenous IFN-γ with mycobacteria enhanced TNF-α and NO release synergistically, we examined the role of endogenous IFN-γ in IL-12/mycobacteria-stimulated macrophage activation. Using macrophages from mice deficient in IFN-γ, we found that IL-12/mycobacteria-enhanced macrophage TNF-α and NO release was mediated through endogenous IFN-γ. We further demonstrated that IFN-γ and mycobacteria together had a selective effect on macrophage cytokine release because they released TNF-α synergistically but not macrophage chemotactic protein-1 (MCP-1). These findings reveal that IL-12 can activate macrophages potently during intracellular infection, and this activating effect is mediated primarily through its effect on macrophage IFN-γ release.
Protein kinase C agonists enhance phagocytosis ofP. aeruginosaby murine alveolar macrophages
Authors: Heale John-Paul , Speert David P
Published: September 2022

Pulmonary alveolar macrophages (AMφs) are incompetent to phagocytose unopsonized Pseudomonas aeruginosa, but ingestion by other macrophage phenotypes (i.e., peritoneal macrophages) occurs efficiently. The purpose of this study was to explore factors that might control such phenotypic differences. Our laboratory has demonstrated that AMφs exposed to sodium azide display enhanced phagocytosis of P. aeruginosa. Here we report that the phagocytic-enhancing effect of sodium azide was abrogated by inhibitors of protein kinase C (PKC). Furthermore, the addition of PKC agonists, such as phorbol myristate acetate (PMA), and tumor necrosis factor α (TNF-α), mimicked the phagocytic enhancing effect of sodium azide. We conclude that AMφs are normally incompetent to phagocytose P. aeruginosa. Factors that up-regulate AMφ function (azide, PMA, TNF-α) can reverse the phagocytic incompetence in vitro. Although these compounds are not appropriate candidate therapeutic agents, their effects provide insights for understanding of the pathways responsible for regulation of P. aeruginosa phagocytosis.
Neutrophil survival is markedly reduced by incubation with influenza virus andStreptococcus pneumoniae: role of respiratory burst
Authors: Engelich Georg , White Mitchell , Hartshorn Kevan L
Published: September 2022

Bacterial superinfections are an important cause of morbidity and mortality during influenza A virus (IAV) epidemics. We demonstrate that incubation with the combination of IAV and Streptococcus pneumoniae caused marked reductions in survival of neutrophils in vitro compared with treatment with control buffer or IAV or S. pneumoniae alone. This cooperative effect was in part mediated by acceleration of neutrophil apoptosis as evidenced by increases in annexin-V binding and caspase-3 activation. However, GM-CSF did not increase survival of neutrophils exposed to IAV and S. pneumoniae. IAV enhanced neutrophil uptake of S. pneumoniae significantly. Furthermore, the combination of IAV and S. pneumoniae caused significantly more hydrogen peroxide production than IAV or S. pneumoniae alone. This increased respiratory burst activity contributed to the diminished neutrophil survival caused by IAV and S. pneumoniae. The NADPH oxidase inhibitor, diphenyleneiodonium, significantly improved survival of neutrophils treated with IAV and S. pneumoniae. These findings may help to explain the increased susceptibility of IAV-infected patients to infections with S. pneumoniae.