Association of TAG-1 with Caspr2 is essential for the molecular organization of juxtaparanodal regions of myelinated fibers

Myelination results in a highly segregated distribution of axonal membrane proteins at nodes of Ranvier. Here, we show the role in this process of TAG-1, a glycosyl-phosphatidyl-inositol-anchored cell adhesion molecule. In the absence of TAG-1, axonal Caspr2 did not accumulate at juxtaparanodes, and the normal enrichment of shaker-type K+ channels in these regions was severely disrupted, in the central and peripheral nervous systems. In contrast, the localization of protein 4.1B, an axoplasmic partner of Caspr2, was only moderately altered. TAG-1, which is expressed in both neurons and glia, was able to associate in cis with Caspr2 and in trans with itself. Thus, a tripartite intercellular protein complex, comprised of these two proteins, appears critical for axo-glial contacts at juxtaparanodes. This complex is analogous to that described previously at paranodes, suggesting that similar molecules are crucial for different types of axo-glial interactions.     

Development of a transient CD4(+)CD8(+) T cell subset in the cervical lymph nodes following intratracheal instillation with an adenovirus vector

Past studies have described the serendipitous appearance of peripheral CD4(+)CD8(+) double-positive (DP) T cells in both humans and nonhuman primates usually following a viral infection or resulting from a malignancy. However, understanding the role of DP T cells has been hampered by the lack of their reproducible generation. Herein, we describe DP T cells produced after a single intratracheal or intranasal dose of recombinant adenovirus 2 or 5 vector into mice. In a time-dependent fashion, DP T cells localized only in the deep cervical lymph nodes but not in the lungs or in any of the respiratory lymph nodes. These DP T cells were TCR(alpha)beta(+) and CD8(alpha)beta(+), but not TCR(gamma)delta(+) nor CD8(alpha)alpha(+), suggesting that these cells are unrelated to intestinally derived DP T cells. Upon co-stimulation with anti-CD3 and anti-CD28, DP T cells showed increased expression of VLA-1, VLA-2, and CD69, and were more effective than CD4(+) T cells in T helper cell activity, as evidenced by increased IgA, IgG, and IgM production. Such co-stimulation also favored the production of IFN-gamma and IL-10 where CD4(+) T cells were more inclined to produce IFN-gamma and IL-2.     

Malnutrition interferes with the unique lymphadenopathy induced in lewis rats by metallic tin

Metallic tin powder injected into Lewis rats caused marked enlargement of draining lymph nodes with prominent hyperplasia of plasma cells. A low level of dietary protein (8%) or deficiency of choline interfered with the cellular proliferation and reduced the size of the nodes by nearly onethird compared to a normal protein diet (20%). A high level of protein in the diet (50%) did not augment the effect of metallic tin powder beyond that achieved by a level usually considered adequate (20%).     

Site-specific differences in the action of NRTI drugs on adipose tissue incubated in vitro with lymphoid cells,and their interaction with dietary lipids

Existing theories of the origin of HIV-related adipose tissue redistribution syndrome cannot adequately explain simultaneous hypertrophy of certain depots and atrophy of others, or its occasional occurrence in untreated HIV infection. These experiments explore the hypothesis that hypertrophy of lymphoid tissue-containing adipose depots arises from drug-induced disruption to local interactions between perinodal adipocytes and activated lymphoid cells. Guinea pigs were fed on plain or lipid-supplemented (10% suet, sunflower or fish oil) chow ad libitum or restricted, and the popliteal lymph nodes were activated by repeated injection of lipopolysaccharide. Explants of perinodal and other samples from popliteal, mesentery, omentum and nodeless perirenal and epididymal depots were incubated with lymphoid cells and zidovudine, didanosine, lamivudine or stavudine at physiological concentrations (0.1-1 microg/ml) or interleukin-10 and interleukin-6, and basal and maximum lipolysis was measured. All drugs increased lipolysis from perinodal adipocytes, especially mesenteric, though less than exogenous cytokines. Effects on adipocytes from non-perinodal sites and nodeless depots were minimal. The sunflower-oil diet enhanced, and the fish-oil and restricted diets reduced, these effects. We conclude that these NRTI antiretroviral drugs modulate the local interactions between perinodal adipocytes and activated lymphoid cells. Local interactions, and hence the selective hypertrophy of node-containing adipose depots, may be curtailed by dietary manipulation.     

In vitro proliferation and in vivo malignancy of cell lines simultaneously derived from a chemically-induced heterogeneous rat mammary tumor

Summary Identification of clones in primary tumors responsible for proliferation, invasion, and metastasis was carried out. Four different aneuploid established cell lines derived from a ductal infiltrating mammary rat tumor induced by 7,12-dimethylbenz[a]anthracene were studied for proliferative and growth features in vitro and for tumorigenic and metastatic potential in vivo in nude mice. Clones, named RM1, RM2, RM3, and RM4, were characterized by different proliferative activity. Clone RM1 showed the highest proliferative activity by both tritiated thymidine incorporation and S-phase flow cytometry, followed by clone RM4. Conversely, clones RM2 and RM3 showed a lower proliferation rate. Growth-promoting activity, tested on 3T3 Swiss cells, was high in all clones, although RM1 showed significantly lower growth factors—releasing activity. Nude mice tumorigenesis demonstrated a strong tumor induction of line RM1 (100% of the mice after 47±7 d) and a slightly lower tumor induction of line RM4 (70% of the mice after 69±9 d). Line RM3 showed tumor induction in 40% of the mice after 186±16 d. Lines RM2 showed no tumor induction. Metastasis occurred in mice treated with line RM1 only. Therefore, tumorigenesis and metastasis correlate with proliferation but not with the release of growth factors. In conclusion, flow cytometry monitoring of clones from heterogeneous primary tumors proved to be a suitable model for the study of in vivo malignancy and in vitro proliferation.     

Proteomic analysis of porcine mesenteric lymph-nodes after Salmonella typhimurium infection

In this study we employed for the first time an in vivo approach coupled to DIGE-based proteomics to explore the response of porcine mesenteric lymph nodes (MLN) to Salmonella typhimurium infection. MLN samples were collected from four control and twelve infected pigs (at 1, 2 and 6 days post infection) for histological analysis, protein and RNA purification. Afterwards, expressed proteins were screened by differential in gel analysis and data were analyzed by bioinformatic tools to generate interaction networks, and identify enriched signaling pathways and biological annotations. S. typhimurium labeling in tissue and phagocyte infiltration were analyzed by immunohistochemistry and RNA was employed to determine the relative expression of immune-related genes by quantitative RNA analysis. The proteome response of porcine MLN to infection was associated to the induction of processes such as phagocyte infiltration, cytoskeleton remodeling and pyroptosis. Moreover, our results suggest that S. typhimurium antigens are cross-presented via MHC-I in a proteasome-dependent manner in porcine MLN. Since pathogen burden in tissue was noticeably reduced at the end of the time course, we infer that host innate and adaptive immunity act in association in MLN to control S. typhimurium dissemination in swine infections.     

Current-year and subsequent-year effects of crop-load manipulation and epicormic-shoot removal on distribution of long, short and epicormic shoot growth in Prunus persica

BACKGROUND AND AIMS: The distribution of canopy growth among different shoot types such as epicormic, long and short shoots is not well understood in the peach tree. In this experiment, the effects of crop load and early epicormic sprout removal on current and subsequent-year distribution of vegetative growth among epicormic, long and short shoots was investigated in Prunus persica. METHODS: Field trials were conducted in Winters, California, in 2003-2004. Crop load was manipulated with fruit thinning in 2003 to produce trees that were de-fruited, commercially thinned or full crop, and half of the trees in each cropping treatment had all current year epicormic sprouts removed at the time of fruit thinning. Yield was recorded and trunk and root carbohydrates were sampled to confirm the effect of 2003 crop load differences on tissue carbohydrate concentration. All current-season vegetative-shoot extension growth was harvested from half of the trees in each treatment in the autumn of 2003 and from the other half in the autumn of 2004. Epicormic, long and short shoots were separately evaluated for dry weight, node number and leaf-stem parameters. KEY RESULTS: In 2003, long-shoot dry weight and node number were significantly affected by crop load; however, short-shoot dry weight and node number were not significantly affected. The 2003 crop-load treatments did not affect 2004 vegetative growth of any shoot type. Some re-growth of epicormic shoots followed early epicormic sprout removal: by the end of the 2003 season, trees in the early shoot-removal treatment had approximately one-third of the epicormic-shoot dry weight as unpruned trees. CONCLUSIONS: Fruit thinning promoted distribution of growth similar to that of de-fruited trees. While thinning was effective in increasing fruit size, it exacerbated the problem of epicormic sprouting. Early epicormic sprout removal did not stimulate the excessive epicormic re-growth in the same or subsequent year relative to previously studied summer pruning methods.     

Chemokine/cytokine production by mononuclear cells from human lymphoid tissues and their modulation by Mycobacterium tuberculosis antigens

The majority of knowledge about the role of cytokines and chemokines in controlling Mycobacterium tuberculosis infection mainly derives from animal models. In humans, this knowledge is still mainly limited to the blood compartment or accessible lymphoid organs, such as tonsils. Here, we studied cytokine and chemokine production and their modulation by M. tuberculosis antigens in mononuclear cells from human blood, spleen and hilar lung lymph nodes. Results show that the kinetics and magnitude of cytokine and chemokine production varied according to the tissue of cell origin. Mycobacterium tuberculosis antigens enhanced cytokine and chemokine production in blood, but the enhancement was restricted in spleen and hilar lung lymph node cells. We show, for the first time in humans, differences in cytokine and chemokine microenvironments according to lymphoid tissues, and suggest that these differences may affect the way cells respond to M. tuberculosis infection.     

初诊腋窝淋巴结阳性乳腺癌新辅助化疗后对腋窝淋巴结转阴性前哨活检的影响分析

摘要 目的：探究对初诊腋窝淋巴结阳性乳腺癌行新辅助化疗患者开展腋窝前哨淋巴结活检的临床意义。方法：选择2017年1月至2020年10月于我院接受改良根治术或保乳术治疗的100例初诊腋窝淋巴结阳性乳腺癌患者,将其中50例病理检测II B、III期行4~8个疗程新辅助化疗后实施前哨淋巴结活检患者设为研究组,将50例I、II A期直接行前哨淋巴结活检患者设为对照组,对比两组患者前哨淋巴结检出率、准确率、假阴性率和灵敏度,同时就患者病理特征与前哨淋巴结检出率的相关性开展分析。结果：（1）比较显示研究组患者与对照组患者在前哨淋巴结检出数、前哨淋巴结检出率以及前哨淋巴结假阴性率方面组间差异不大（P>0.05）;（2）病理学特征分析显示肿瘤直径以及临床N分期同新辅助化疗后患者前哨淋巴结检出阳性率密切相关（P<0.05）。结论：对初诊腋窝淋巴结阳性行新辅助化疗乳腺癌患者实施前哨淋巴结活检具有较显示的临床意义,能够较好的预测患者腋窝淋巴结状况,同时化疗前肿瘤直径、临床N分期是影响前哨淋巴结检出率的重要影响因素。     

Single-cell analysis reveals metastatic cell heterogeneity in clear cell renal cell carcinoma

Renal cell carcinoma (RCC) is one of the leading causes of cancer-related death worldwide. Tumour metastasis and heterogeneity lead to poor survival outcomes and drug resistance in patients with metastatic RCC (mRCC). In this study, we aimed to assess intratumoural heterogeneity (ITH) in mRCC cells by performing a combined analysis of bulk data and single-cell RNA-sequencing data, and develop novel biomarkers for prognosis prediction on the basis of the potential molecular mechanisms underlying tumorigenesis. Eligible single-cell cohorts related to mRCC were acquired using the Gene Expression Omnibus (GEO) dataset to identify potential mRCC subpopulations. We then performed gene set variation analysis to understand the differential function in primary RCC and mRCC samples. Subsequently, we applied weighted correlation network analysis to identify coexpressing gene modules that were related to the external trait of metastasis. Protein-protein interactions were used to screen hub subpopulation-difference (sub-dif) markers (ACTG1, IL6, CASP3, ACTB and RAP1B) that might be involved in the regulation of RCC metastasis and progression. Cox regression analysis revealed that ACTG1 was a protective factor (HR < 1), whereas the other four genes (IL6, CASP3, ACTB and RAP1B) were risk factors (HR > 1). Kaplan-Meier survival analysis suggested the potential prognostic value of these sub-dif markers. The expression of sub-dif markers in mRCC was further evaluated in clinical samples by immunohistochemistry (IHC). Additionally, the genetic features of sub-dif marker expression patterns, such as genetic variation profiles, correlations with tumour-infiltrating lymphocytes (TILs), and targeted signalling pathway activities, were assessed in bulk RNA-seq datasets. In conclusion, we established novel subpopulation markers as key prognostic factors affecting EMT-related signalling pathway activation in mRCC, which could facilitate the implementation of a treatment for mRCC patients.