Interleukin 6-regulated macrophage polarization controls atherosclerosis-associated vascular intimal hyperplasia.

Vascular intimal hyperplasia (VIH) is an important stage of atherosclerosis (AS), in which macrophages not only play a critical role in local inflammation, but also transform into foam cells to participate into plaque formation, where they appear to be heterogeneous. Recently, it was shown that CD11c+ macrophages were more associated with active plaque progression. However, the molecular regulation of phenotypic changes of plaque macrophages during VIH has not been clarified and thus addressed in the current study. Since CD11c- cells were M2a-polarized anti-inflammatory macrophages, while CD11c+ cells were M1/M2b-polarized pro-inflammatory macrophages, we used bioinformatics tools to analyze the CD11c+ versus CD11c- plaque macrophages, aiming to detect the differential genes associated with M1/M2 macrophage polarization. We obtained 122 differential genes that were significantly altered in CD11c+ versus CD11c- plaque macrophages, regardless of CD11b expression. Next, hub genes were predicted in these 122 genes, from which we detected 3 candidates, interleukin 6 (Il6), Decorin (Dcn) and Tissue inhibitor matrix metalloproteinase 1 (Timp1). The effects of these 3 genes on CD11c expression as well as on the macrophage polarization were assessed in vitro, showing that only expression of Il6, but not expression of Dcn or Timp1, induced M1/M2b-like polarization in M2a macrophages. Moreover, only suppression of Il6, but not suppression of either of Dcn or Timp1, induced M2a-like polarization in M1/M2b macrophages. Furthermore, pharmaceutical suppression of Il6 attenuated VIH formation and progression of AS in a mouse model that co-applied apolipoprotein E-knockout and high-fat diet. Together, our data suggest that formation of VIH can be controlled through modulating macrophage polarization, as a promising therapeutic approach for prevent AS.

BMP signaling in the intestinal epithelium drives a critical feedback loop to restrain IL-13-driven tuft cell hyperplasia.

The intestinal tract is a common site for various types of infections including viruses, bacteria, and helminths, each requiring specific modes of immune defense. The intestinal epithelium has a pivotal role in both immune initiation and effector stages, which are coordinated by lymphocyte cytokines such as IFNγ, IL-13, and IL-22. Here, we studied intestinal epithelial immune responses using organoid image analysis based on a convolutional neural network, transcriptomic analysis, and in vivo infection models. We found that IL-13 and IL-22 both induce genes associated with goblet cells, but the resulting goblet cell phenotypes are dichotomous. Moreover, only IL-13-driven goblet cells are associated with classical NOTCH signaling. We further showed that IL-13 induces the bone morphogenetic protein (BMP) pathway, which acts in a negative feedback loop on immune type 2-driven tuft cell hyperplasia. This is associated with inhibiting Sox4 expression to putatively limit the tuft cell progenitor population. Blocking ALK2, a BMP receptor, with the inhibitor dorsomorphin homolog 1 (DMH1) interrupted the feedback loop, resulting in greater tuft cell numbers both in vitro and in vivo after infection with Nippostrongylus brasiliensis. Together, this investigation of cytokine effector responses revealed an unexpected and critical role for the BMP pathway in regulating type 2 immunity, which can be exploited to tailor epithelial immune responses.

Light Chain-Restricted Plasmacytoid Cells in Hyperplastic Germinal CentersA Clinicopathologic Investigation.

OBJECTIVES: Follicular hyperplasias (FHs) with light chain-restricted (LCR) plasmacytoid/plasma cells (PCs) within germinal centers (GCs) based on immunohistochemistry (IHC)/in situ hybridization (ISH) can potentially lead to diagnostic error. This study aims to better characterize such cases, including their clinical implications. METHODS: LC expression by IHC/ISH was quantitatively assessed in GCs of 17 FHs with LCRGCs. BCL2, CD10, BCL6, BCL2, immunoglobulin (Ig) heavy chains, IgG4, and Epstein-Barr encoding region stains were performed. In total, 8 cases had polymerase chain reaction (PCR)-based clonality studies. RESULTS: All cases showed FH, including 4 with progressively transformed GCs (PTGCs); 0.8% to 52% (median, 21%) of the GCs were LCR; 13 of 17 had both κ- and λ-LCRGCs, and 4 of 17 had only κ-LCRGCs; 7 of 16 had prominent intrafollicular IgG4-positive cells. One case demonstrated BCL2-positive cells in focal LCRGCs but lacked BCL2 rearrangement. B-cell monoclonality was demonstrated in 3 of 8 cases (only after microdissection). Seven patients had autoimmune disorders, and 1 had had a transplant. Three patients had a history of lymphoma, 1 developed lymphoma, and 1 developed lymphomatoid granulomatosis subsequently. CONCLUSIONS: FHs with LCRGC by IHC/ISH are typically not associated with the development of lymphoma, even though they can express BCL2 and show monoclonality by PCR. They may be associated with increased intrafollicular IgG4-positive cells, PTGC, and autoimmunity.

The p53 status in rheumatoid arthritis with focus on fibroblast-like synoviocytes.

P53 is a transcription factor that regulates many signaling pathways like apoptosis, cell cycle, DNA repair, and cellular stress responses. P53 is involved in inflammatory responses through the regulation of inflammatory signaling pathways, induction of cytokines, and matrix metalloproteinase expression. Also, p53 regulates immune responses through modulating Toll-like receptors expression and innate and adaptive immune cell differentiation and maturation. P53 is a modulator of the apoptosis and proliferation processes through regulating multiple anti and pro-apoptotic genes. Rheumatoid arthritis (RA) is categorized as an invasive inflammatory autoimmune disease with irreversible deformity of joints and bone resorption. Different immune and non-immune cells contribute to RA pathogenesis. Fibroblast-like synoviocytes (FLSs) have been recently introduced as a key player in the pathogenesis of RA. These cells in RA synovium produce inflammatory cytokines and matrix metalloproteinases which results in synovitis and joint destruction. Besides, hyper proliferation and apoptosis resistance of FLSs lead to synovial hyperplasia and bone and cartilage destruction. Given the critical role of p53 in inflammation, apoptosis, and cell proliferation, lack of p53 function (due to mutation or low expression) exerts a prominent role for this gene in the pathogenesis of RA. This review focuses on the role of p53 in different mechanisms and cells (specially FLSs) that involved in RA pathogenesis.

Tick-human interactions: from allergic klendusity to the α-Gal syndrome.

Ticks and the pathogens they transmit, including bacteria, viruses, protozoa, and helminths, constitute a growing burden for human and animal health worldwide. The ability of some animal species to acquire resistance to blood-feeding by ticks after a single or repeated infestation is known as acquired tick resistance (ATR). This resistance has been associated to tick-specific IgE response, the generation of skin-resident memory CD4+ T cells, basophil recruitment, histamine release, and epidermal hyperplasia. ATR has also been associated with protection to tick-borne tularemia through allergic klendusity, a disease-escaping ability produced by the development of hypersensitivity to an allergen. In addition to pathogen transmission, tick infestation in humans is associated with the α-Gal syndrome (AGS), a type of allergy characterized by an IgE response against the carbohydrate Galα1-3Gal (α-Gal). This glycan is present in tick salivary proteins and on the surface of tick-borne pathogens such as Borrelia burgdorferi and Anaplasma phagocytophilum, the causative agents of Lyme disease and granulocytic anaplasmosis. Most α-Gal-sensitized individuals develop IgE specific against this glycan, but only a small fraction develop the AGS. This review summarizes our current understanding of ATR and its impact on the continuum α-Gal sensitization, allergy, and the AGS. We propose that the α-Gal-specific IgE response in humans is an evolutionary adaptation associated with ATR and allergic klendusity with the trade-off of developing AGS.

Infiltration of Immune Competent Cells into Primary Tumors and Their Surrounding Connective Tissues in Xenograft and Syngeneic Mouse Models.

To fight cancer more efficiently with cell-based immunotherapy, more information about the cells of the immune system and their interaction with cancer cells in vivo is needed. Therefore paraffin wax embedded primary breast cancers from the syngeneic mouse WAP-T model and from xenografted tumors of breast, colon, melanoma, ovarian, neuroblastoma, pancreatic, prostate, and small cell lung cancer were investigated for the infiltration of immunocompetent cells by immunohistochemistry using antibodies against leukocyte markers. The following markers were used: CD45 as a pan-leukocyte marker, BSA-I as a dendritic cell marker, CD11b as an NK cell marker, and CD68 as a marker for macrophages. The labeled immune cells were attributed to the following locations: adjacent adipose tissue, tumor capsule, intra-tumoral septae, and cancer cells directly. In xenograft tumors, the highest score of CD45 and CD11b positive, NK, and dendritic cells were found in the adjacent adipose tissue, followed by lesser infiltration directly located at the cancer cells themselves. The detected numbers of CD45 positive cells differed between the tumor entities: few infiltrating cells in breast cancer, small cell lung cancer, neuroblastoma, a moderate infiltration in colon cancer, melanoma and ovarian cancer, strongest infiltration in prostate and pancreatic cancer. In the syngeneic tumors, the highest score of CD45 and CD11b positive, NK and dendritic cells were observed in the tumor capsule, followed by a lesser infiltration of the cancer tissue. Our findings argue for paying more attention to investigate how immune-competent cells can reach the tumor cells directly.

Basophils promote barrier dysfunction and resolution in the atopic skin.

BACKGROUND: The type 2 cytokines IL-4 and IL-13 promote not only atopic dermatitis (AD) but also the resolution of inflammation. How type 2 cytokines participate in the resolution of AD is poorly known. OBJECTIVE: Our aim was to determine the mechanisms and cell types governing skin inflammation, barrier dysfunction, and resolution of inflammation in a model of AD. METHODS: Mice that exhibit expression of IL-4, IL-13, and MCPT8 or that could be depleted of basophils or eosinophils, be deficient in IL-4 or MHC class II molecules, or have basophils lacking macrophage colony-stimulating factor (M-CSF) were treated with calcipotriol (MC903) as an acute model of AD. Kinetics of the disease; keratinocyte differentiation; and leukocyte accumulation, phenotype, function, and cytokine production were measured by transepidermal water loss, histopathology, molecular biology, or unbiased analysis of spectral flow cytometry. RESULTS: In this model of AD, basophils were activated systemically and were the initial and main source of IL-4 in the skin. Basophils and IL-4 promoted epidermal hyperplasia and skin barrier dysfunction by acting on keratinocyte differentiation during inflammation. Basophils, IL-4, and basophil-derived M-CSF inhibited the accumulation of proinflammatory cells in the skin while promoting the expansion and function of proresolution M2-like macrophages and the expression of probarrier genes. Basophils kept their proresolution properties during AD resolution. CONCLUSION: Basophils can display both beneficial and detrimental type 2 functions simultaneously during atopic inflammation.

Diagnostic value of sialyl-Tn immunocytochemistry in breast cancer presenting with pathological nipple discharge.

BACKGROUND: Mucin-associated sialyl-Tn (sTn) antigen is overexpressed and related with adverse outcome in breast cancer (BC). The role of sTn in BC has not been well defined in pathological nipple discharge (PND) cytology. The authors examined sTn immunocytochemistry (ICC) in PND to determine whether it could be a biomarker of malignancy or aggressive disease. METHODS: PND was subjected to immunocytochemical staining for sTn antigen expression and thinprep cytology test (TCT) for enhancing the sensitivity and specificity. The examination data was compared with histological findings of subsequent biopsy specimens. Logistic regression analysis was used to determine which factors were most associated with malignant breast lesions. RESULTS: PND specimens were collected including 120 cases of intraductal papilloma, 24 cases of hyperplasia, 45 cases of ductal carcinoma in situ (DCIS), and 48 cases of invasive ductal carcinoma (IDC). STn ICC differentiated BC from benign intraductal lesions with a low sensitivity of 41.9% and a high specificity of 95.8%, but increased in combination with TCT to 64.5% and 100%, respectively. A high degree of concordance was observed between the results of sTn expression in cell smears and histological specimens. Moreover, the sTn expression was strongly associated with HER2-positive IDC (p = 0.039). Multivariate logistic analysis showed that positive sTn expression (OR: 14.241, 95%CI: 2.574, 78.794, p = 0.010) and accompanying mass (OR: 3.307, 95%CI: 1.073, 10.188, p = 0.037) were statistically significant independent risk factors for malignant PND. CONCLUSIONS: Mucin-associated sTn expression in PND cytology appears to be a reliable diagnostic marker for BC patients with the chief complaint of malignant nipple discharge and indicates a more aggressive behavior in IDC.

OVOL1 Regulates Psoriasis-Like Skin Inflammation and Epidermal Hyperplasia.

Psoriasis is a common inflammatory skin disease characterized by aberrant inflammation and epidermal hyperplasia. Molecular mechanisms that regulate psoriasis-like skin inflammation remain to be fully understood. Here, we show that the expression of Ovol1 (encoding ovo-like 1 transcription factor) is upregulated in psoriatic skin, and its deletion results in aggravated psoriasis-like skin symptoms following stimulation with imiquimod. Using bulk and single-cell RNA sequencing, we identify molecular changes in the epidermal, fibroblast, and immune cells of Ovol1-deficient skin that reflect an altered course of epidermal differentiation and enhanced inflammatory responses. Furthermore, we provide evidence for excessive full-length IL-1α signaling in the microenvironment of imiquimod-treated Ovol1-deficient skin that functionally contributes to immune cell infiltration and epidermal hyperplasia. Collectively, our study uncovers a protective role for OVOL1 in curtailing psoriasis-like inflammation and the associated skin pathology.

Non-Cell-Autonomous Activity of the Hemidesmosomal Protein BP180/Collagen XVII in Granulopoiesis in Humanized NC16A Mice.

BP180 (also termed type XVII collagen) is a hemidesmosomal protein and plays a critical role in cell-cell matrix adhesion in the skin; however, its other biological functions are largely unclear. In this study, we generated a BP180 functional-deficient mouse strain by deleting its extracellular domain of humanized NC16A (termed ΔNC16A mice). We found that BP180 is expressed by bone marrow mesenchymal stem cells (BM-MSC), and its functional deficiency leads to myeloid hyperplasia. Altered granulopoiesis in ΔNC16A mice is through bone marrow stromal cells evidenced by bone marrow transplantation. Furthermore, the level of G-CSF in bone marrow and circulation were significantly increased in ΔNC16A mice as compared with wild-type mice. The increased G-CSF was accompanied by an increased activation of the NF-κB signaling pathway in bone marrow and BM-MSC of ΔNC16A mice. Blockade of G-CSF restored normal granulopoiesis in ΔNC16A mice. Inhibition of NF-κB signaling pathway significantly reduces the release of G-CSF from ΔNC16A BM-MSC in vitro and the level of serum G-CSF in ΔNC16A mice. To our knowledge, these findings provide the first direct evidence that BP180 plays an important role in granulopoiesis through regulating NF-κB signaling pathway in BM-MSC.

Development and characterization of a mouse model of duodenogastric reflux.

AIMS: Rat models of duodenogastric reflux have been used to study gastric stump cancer (GSC), but the underlying molecular mechanisms are poorly understood. Unlike rats, mice can be genetically modified, providing a superior model for studying the molecular mechanisms underlying GSC development, which is associated with duodenogastric reflux. This study aimed at developing a mouse model of duodenogastric reflux. MAIN METHOD: C57BL/6 mice were randomly assigned to the control (n = 6), sham operation (n = 9), or gastrojejunostomy group (n = 12). Mice were sacrificed at 1, 3, and 6 months after surgery. Stomach tissue was stained with hematoxylin and eosin. Lesions were classified as chronic inflammation, intestinal metaplasia, or atypical hyperplasia. KEY FINDINGS: Nine mice underwent gastrojejunostomy without mortality. The animals in the gastrojejunostomy group exhibited chronic inflammation at 1, 3, and 6 months after surgery, showing intestinal metaplasia (n = 2) and atypical hyperplasia (n = 1) at 3 months and intestinal metaplasia (n = 2) and atypical hyperplasia (n = 2) at 6 months. The mice in the control group did not exhibit chronic inflammation or intestinal metaplasia, whereas those in the sham operation group exhibited chronic inflammation at 1, 3, and 6 months after surgery, without intestinal metaplasia or atypical hyperplasia. Intestinal metaplasia or atypical hyperplasia were more common in the gastrojejunostomy group than in the sham operation group (p = 0.012). SIGNIFICANCE: A duodenogastric reflux mouse model can be created using gastrojejunostomy without gastrectomy.

MicroRNA-16 directly binds to DEC2 and inactivates the TLR4 signaling pathway to inhibit lupus nephritis-induced kidney tissue hyperplasia and mesangial cell proliferation.

Lupus nephritis (LN) is the most serious manifestation of systemic lupus erythematosus (SLE) and a major risk of mortality. This research focused on the function of microRNA-16 (miR-16) in LN development. Fcgamma receptor II-b-deficient (Fcgr2b-/-) mice with the natural potential to develop SLE- and LN-like diseases were used. Gain- and loss-of-function studies were performed to explore the function of miR-16 in pathological symptoms in mouse kidney tissues and the proliferation of mesangial cells (SV40 MES-13). The putative downstream molecules of miR-16 were explored. Consequently, poor expression of miR-16 was found in kidney tissues. Upregulation of miR-16 inhibited tissue hyperplasia, inflammatory infiltration, glomerular injury and fibrosis but increased cell apoptosis in mouse kidney tissues, and it inhibited proliferation but promoted apoptosis of MES-13 cells as well. miR-16 directly bound to DEC2 and inactivated the TLR4 signaling. DEC2 blocked the protective roles of miR-16 in MES-13 cells. The enhanced proliferation in MES-13 cells following miR-16 inhibition was reversed by chloroquine phosphate, a TLR4 antagonist. To sum up, miR-16 was evidenced to have a potent protective capacity in LN through relieving the LN symptoms in kidney tissues and reducing proliferation of mesangial cells, during which DEC2 silencing and TLR4 signaling deficit were involved.

Innate Immune Molecule NLRC5 Protects Mice From Helicobacter-induced Formation of Gastric Lymphoid Tissue.

BACKGROUND & AIMS: Helicobacter pylori induces strong inflammatory responses that are directed at clearing the infection, but if not controlled, these responses can be harmful to the host. We investigated the immune-regulatory effects of the innate immune molecule, nucleotide-binding oligomerization domain-like receptors (NLR) family CARD domain-containing 5 (NLRC5), in patients and mice with Helicobacter infection. METHODS: We obtained gastric biopsies from 30 patients in Australia. We performed studies with mice that lack NLRC5 in the myeloid linage (Nlrc5møKO) and mice without Nlrc5 gene disruption (controls). Some mice were gavaged with H pylori SS1 or Helicobacter felis; 3 months later, stomachs, spleens, and sera were collected, along with macrophages derived from bone marrow. Human and mouse gastric tissues and mouse macrophages were analyzed by histology, immunohistochemistry, immunoblots, and quantitative polymerase chain reaction. THP-1 cells (human macrophages, controls) and NLRC5-/- THP-1 cells (generated by CRISPR-Cas9 gene editing) were incubated with Helicobacter and gene expression and production of cytokines were analyzed. RESULTS: Levels of NLRC5 messenger RNA were significantly increased in gastric tissues from patients with H pylori infection, compared with patients without infection (P < .01), and correlated with gastritis severity (P < .05). H pylori bacteria induced significantly higher levels of chemokine and cytokine production by NLRC5-/- THP-1 macrophages than by control THP-1 cells (P < .05). After 3 months of infection with H felis, Nlrc5mø-KO mice developed gastric hyperplasia (P < .0001), splenomegaly (P < .0001), and increased serum antibody titers (P < .01), whereas control mice did not. Nlrc5mø-KO mice with chronic H felis infection had increased numbers of gastric B-cell follicles expressing CD19 (P < .0001); these follicles had features of mucosa-associated lymphoid tissue lymphoma. We identified B-cell-activating factor as a protein that promoted B-cell hyperproliferation in Nlrc5mø-KO mice. CONCLUSIONS: NLRC5 is a negative regulator of gastric inflammation and mucosal lymphoid formation in response to Helicobacter infection. Aberrant NLRC5 signaling in macrophages can promote B-cell lymphomagenesis during chronic Helicobacter infection.

A network pharmacology approach to explore the potential targets underlying the effect of sinomenine on rheumatoid arthritis.

OBJECTIVE: To explore the potential targets underlying the effect of sinomenine (SIN) on rheumatoid arthritis (RA) by utilizing a network pharmacology approach. METHODS: SIN and its drug targets were identified using network analysis followed by experimental validation. First, the Pharmmapper, UniProt and GeneCards databases were mined for information relevant to the prediction of SIN targets and RA-related targets. Second, the SIN-target gene and SIN-RA target gene networks were created in Cytoscape software followed by the collection of the candidate targets of each component by R software. Eventually, the key targets and enriched pathways were examined by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. RESULTS: Sixty-seven potential targets of SIN and 3797 related targets involved in RA were subjected to network analysis, and the 20 intersection targets indicated the principal pathways linked to RA. Additionally, 16 key targets, which were linked to more than three genes, were determined to be crucial genes. GO analysis showed that 14 biological processes, 5 cellular components and 2 molecular functions were identified, when corrected by a P value ≤ 0.01. Seven related signaling pathways were identified by KEGG analysis, when corrected according to a Bonferroni P value ≤ 0.05. CONCLUSION: The present study explored the potential targets and signaling pathways of SIN during the treatment of RA, which may help to illustrate the mechanism (s) involved in the action of SIN and may provide a better understanding of its anti-rheumatoid arthritis effects in terms of inhibiting angiogenesis, synovial hyperplasia, and bone destruction.

Gene Expression Profiling Revealed 2 Types of Bronchial Basal Cell Hyperplasia and Squamous Metaplasia With Different Progression Potentials.

The premalignant process preceding squamous cell lung cancer is not inevitable; it can stop at any of the bronchial lesions: basal cell hyperplasia (BCH), squamous metaplasia (SM), and dysplasia and then progress or regress. At present, the mechanisms underlying the progression of the bronchial lesions remain undefined. Previously, we hypothesized that bronchial lesions that presented individually or combined with each other in the bronchi of lung cancer patients mirror the different "scenarios" of the premalignant process: individual BCH-the stoppage at the stage of hyperplasia, BCH plus SM-the progression of hyperplasia to metaplasia, and SM plus dysplasia-the progression of metaplasia to dysplasia. In this study, we analyzed gene expression profiles of BCH, SM, and dysplasia depending on their cooccurrence in the bronchi of lung cancer patients. The immune response gene expression was found to be a key difference between the individual BCH and BCH combined with SM lesions and a potential mechanism that determines the progression of hyperplasia to metaplasia. Upregulation of the cell cycle and downregulation of the cilium assembly genes mainly distinguished SM that copresented with dysplasia from SM that copresented with BCH and is a probable mechanism of the progression of metaplasia to dysplasia. Dysplasia showed mainly overexpression of the cell division genes and underexpression of the inflammation genes. Thus, this study demonstrates the significant gene expression differences between the premalignant lesions depending on their cooccurrence in the bronchi and sheds light on the mechanisms of the precancerous process preceding squamous cell lung cancer.

Cecal Tumorigenesis in Aryl Hydrocarbon Receptor-Deficient Mice Depends on Cecum-Specific Mitogen-Activated Protein Kinase Pathway Activation and Inflammation.

The aryl hydrocarbon receptor (AhR) is a transcription factor known as a dioxin receptor. Recently, Ahr-/- mice were revealed to develop cecal tumors with inflammation and Wnt/ß-catenin pathway activation. However, whether ß-catenin degradation is AhR dependent remains unclear. To determine whether other signaling pathways function in Ahr-/- cecal tumorigenesis, we investigated histologic characteristics of the tumors and cytokine/chemokine production in tumors and Ahr-/- peritoneal macrophages. AhR expression was also assessed in human colorectal carcinomas. Of the 28 Ahr-/- mice, 10 developed cecal lesions by 50 weeks of age, an incidence significantly lower than previously reported. Cecal lesions of Ahr-/- mice developed from serrated hyperplasia to adenoma/dysplasia-like neoplasia with enhanced proliferation. Macrophage and neutrophil infiltration into the lesions was also observed early in serrated hyperplasia, although adjacent mucosa was devoid of inflammation. Il1b, Il6, Ccl2, and Cxcl5 were up-regulated at lesion sites, whereas only IL-6 production increased in Ahr-/- peritoneal macrophages after lipopolysaccharide + ATP stimulation. Neither Myc (alias c-myc) up-regulation nor ß-catenin nuclear translocation was observed, unlike previously reported. Interestingly, enhanced phosphorylation of extracellular signal-regulated kinase, Src, and epidermal growth factor receptor and Amphiregulin up-regulation at Ahr-/- lesion sites were detected. In human serrated lesions, however, AhR expression in epithelial cells was up-regulated despite morphologic similarity to Ahr-/- cecal lesions. Our results suggest novel mechanisms underlying Ahr-/- cecal tumorigenesis, depending primarily on cecum-specific mitogen-activated protein kinase pathway activation and inflammation.

The life and death of the germinal center.

The formation, development and dissolution of germinal centers is a major part of immune system function. It is important to differentiate neoplastic processes from follicular hyperplasia and regressive follicular changes. Better understanding of germinal center development and dissolution also provides diagnostic clues to the underlying pathologic process. It is also important in identifying the immune basis of different pathologic entities as well as in immunotherapy decision making and follow up. In this study, we characterize the immunoarchitecture of lymphoid follicles with a focus on germinal center in one representative case, each of commonly encountered benign and malignant lymph node disorders, with morphologic and immunohistochemical alterations of germinal centers. The cases include reactive follicular hyperplasia (FH), florid follicular hyperplasia (FFH), follicular lymphoma (FL), angioimmunoblastic T-cell lymphoma (AITL), hyaline-vascular Castleman disease (HVCD), progressive transformation of germinal centers, nodular lymphocyte predominant Hodgkin lymphoma (NLPHL), lymphocyte-rich classic Hodgkin lymphoma (LR-CHL), human immunodeficiency virus (HIV)-associated follicular dissolution and chronic lymphocytic leukemia (CLL) with proliferation centers (PC). A panel of antibodies were used namely CD3, CD20, CD10, BCL2, BCL6, CD21, CD23, CD35, FOXP1, GCET1, HGAL/GCET2, LMO2, MUM1, IgD, Ki67, PD1 and PD-L1. We found that these entities show distinct immunoarchitectural patterns of germinal center formation, development and regression, particularly, the distribution of mantle zone B-cells, follicular helper T cells (Tfh) and FDC meshworks, confirming the influence of antigenic stimulation and status of immune system in these changes. This also confirms the interrelationship of underlying immunologic mechanisms in these disease processes.

Primary myelofibrosis marrow-derived CD14+/CD34- monocytes induce myelofibrosis-like phenotype in immunodeficient mice and give rise to megakaryocytes.

To confirm that neoplastic monocyte-derived collagen- and fibronectin-producing fibrocytes induce bone marrow (BM) fibrosis in primary myelofibrosis (PMF), we injected PMF BM-derived fibrocyte-precursor CD14+/CD34- monocytes into the tail vein of NOD-SCID-γ (NSG) mice. PMF BM-derived CD14+/CD34- monocytes engrafted and induced a PMF-like phenotype with splenomegaly, myeloid hyperplasia with clusters of atypical megakaryocytes, persistence of the JAK2V617F mutation, and BM and spleen fibrosis. As control we used normal human BM-derived CD14+/CD34- monocytes. These monocytes also engrafted and gave rise to normal megakaryocytes that, like PMF CD14+/CD34--derived megakaryocytes, expressed HLA-ABC and human CD42b antigens. Using 2 clonogenic assays we confirmed that PMF and normal BM-derived CD14+/CD34- monocytes give rise to megakaryocyte colony-forming cells, suggesting that a subpopulation BM monocytes harbors megakaryocyte progenitor capacity. Taken together, our data suggest that PMF monocytes induce myelofibrosis-like phenotype in immunodeficient mice and that PMF and normal BM-derived CD14+/CD34- monocytes give rise to megakaryocyte progenitor cells.

Gastric parietal cell and thyroid autoantibodies in oral precancer patients.

BACKGROUND/PURPOSE: Gastric parietal cell antibody (GPCA), thyroglobulin antibody (TGA), and thyroid microsomal antibody (TMA) may be present in oral mucosal disease patients. This study mainly assessed the frequencies of serum GPCA, TGA, and TMA positivities in 131 oral precancer patients. METHODS: Serum GPCA, TGA, and TMA levels were measured in 131 oral precancer patients including 96 oral leukoplakia, 26 oral erythroleukoplakia, and 9 oral verrucous hyperplasia patients and in 131 age- and sex-matched healthy control subjects. RESULTS: We found that 131 oral precancer patients had higher frequencies of serum GPCA (10.7% vs. 2.3%, P = 0.012, statistically significant), TGA (4.6% vs. 2.3%, P = 0.498), and TMA (8.4% vs. 2.3%, P = 0.054, marginal significance) positivities than 131 healthy control subjects. We also found that 1 (0.8%), 6 (4.6%), and 16 (12.2%) oral precancer patients had the presence of three (GPCA + TGA + TMA), two (GPCA + TGA, GPCA + TMA, or TGA + TMA), or one (GPCA only, TGA only, or TMA only) autoantibody in their sera, respectively. Of 10 TGA/TMA-positive oral precancer patients whose serum thyroid-stimulating hormone (TSH) levels were measured, 80%, 10%, and 10% of these 10 TGA/TMA-positive oral precancer patients had normal, lower, and higher serum TSH levels, respectively. We also found a significantly higher GPCA positive rate in 26 smokers consuming >20 cigarettes per day than in 61 smokers consuming ≤20 cigarettes per day (P = 0.008). CONCLUSION: Approximately 17.6% of 131 oral precancer patients have serum GPCA/TGA/TMA positivity. Only approximately 20% of TGA/TMA-positive oral precancer patients have either hypothyroidism or hyperthyroidism.

BAFF-driven B cell hyperplasia underlies lung disease in common variable immunodeficiency.

BACKGROUND: Common variable immunodeficiency (CVID) is the most common symptomatic primary immunodeficiency and is frequently complicated by interstitial lung disease (ILD) for which etiology is unknown and therapy inadequate. METHODS: Medical record review implicated B cell dysregulation in CVID ILD progression. This was further studied in blood and lung samples using culture, cytometry, ELISA, and histology. Eleven CVID ILD patients were treated with rituximab and followed for 18 months. RESULTS: Serum IgM increased in conjunction with ILD progression, a finding that reflected the extent of IgM production within B cell follicles in lung parenchyma. Targeting these pulmonary B cell follicles with rituximab ameliorated CVID ILD, but disease recurred in association with IgM elevation. Searching for a stimulus of this pulmonary B cell hyperplasia, we found B cell-activating factor (BAFF) increased in blood and lungs of progressive and post-rituximab CVID ILD patients and detected elevation of BAFF-producing monocytes in progressive ILD. This elevated BAFF interacts with naive B cells, as they are the predominant subset in progressive CVID ILD, expressing BAFF receptor (BAFF-R) within pulmonary B cell follicles and blood to promote Bcl-2 expression. Antiapoptotic Bcl-2 was linked with exclusion of apoptosis from B cell follicles in CVID ILD and increased survival of naive CVID B cells cultured with BAFF. CONCLUSION: CVID ILD is driven by pulmonary B cell hyperplasia that is reflected by serum IgM elevation, ameliorated by rituximab, and bolstered by elevated BAFF-mediated apoptosis resistance via BAFF-R. FUNDING: NIH, Primary Immune Deficiency Treatment Consortium, and Rare Disease Foundation.