Quantitative analysis of rough endoplasmic reticulum approaches to the cell membrane in the secretory ameloblast of the rat incisor

Systemic dysfunction and plasticity of the immune macroenvironment in cancer models

Understanding of the factors governing immune responses in cancer remains incomplete, limiting patient benefit. In this study, we used mass cytometry to define the systemic immune landscape in response to tumor development across five tissues in eight mouse tumor models. Systemic immunity was dramatically altered across models and time, with consistent findings in the peripheral blood of patients with breast cancer. Changes in peripheral tissues differed from those in the tumor microenvironment. Mice with tumor-experienced immune systems mounted dampened responses to orthogonal challenges, including reduced T cell activation during viral or bacterial infection. Antigen-presenting cells (APCs) mounted weaker responses in this context, whereas promoting APC activation rescued T cell activity. Systemic immune changes were reversed with surgical tumor resection, and many were prevented by interleukin-1 or granulocyte colony-stimulating factor blockade, revealing remarkable plasticity in the systemic immune state. These results demonstrate that tumor development dynamically reshapes the composition and function of the immune macroenvironment.

Pinealocyte subsurface cisterns. I: Cytological aspects including three-dimensional structure

Subsurface cisterns (ssc) in the pineal gland of Meriones unguiculatus have been characterized with transmission electron microscopy, freeze-fracture, morphometry, and three-dimensional reconstruction. Subsurface cisterns (which are observed only in pinealocytes and never in gliocytes) are cisterns of the endoplasmic reticulum (ER) approaching the plasmalemma at a distance of 15-20 nm. Freeze-fracture preparations show that except for some ribosomes at the cytoplasmic face, the cistern membranes as well as the related portions of the plasmalemma are free of special or specifically arranged particles or pores. All ssc have a lumen of 15-20 nm width and underlie 5.6% of the plasmalemma in a single layer; neither collapsed types nor stacks of ssc could be observed. As seen from reconstructions, large ssc are fenestrated and are situated preferentially in regions where the neighboring pinealocyte also bears large ssc. As a consequence, double-sided ssc, which can be observed in sections of (mostly large) ssc, are not a random phenomenon. In regions of the large ssc, adhering junctions are also concentrated. Tubules of 20-nm diameter link ssc with deeper parts of the ER, particularly with the perinuclear cistern and with the tubulo-cisternal network at the trans-side of the Golgi apparatus. Besides ssc proper, a lot of small endplates of ER-tubules are seen close to the plasmalemma. It is suggested that ssc form by the widening and fusing of such ER-tubules and decrease by retraction of ER-tubules from the cell surface.