Array tomography: characterizing FAC-sorted populations of zebrafish immune cells by their 3D ultrastructure.

For 3D reconstructions of whole immune cells from zebrafish, isolated from adult animals by FAC-sorting we employed array tomography on hundreds of serial sections deposited on silicon wafers. Image stacks were either recorded manually or automatically with the newly released ZEISS Atlas 5 Array Tomography platform on a Zeiss FEGSEM. To characterize different populations of immune cells, organelle inventories were created by segmenting individual cells. In addition, arrays were used for quantification of cell populations with respect to the various cell types they contained. The detection of immunological synapses in cocultures of cell populations from thymus or WKM with cancer cells helped to identify the cytotoxic nature of these cells. Our results demonstrate the practicality and benefit of AT for high-throughput ultrastructural imaging of substantial volumes.

Histological and ultrastructural examinations of porcine tonsils.

The histology and ultrastructure of porcine tonsils were studied. The porcine tonsils were lymphoepithelial organs situated at the opening of both the digestive and respiratory tracts. The tonsil of the soft palate in the oropharyngeal tract and the paraepiglottic tonsil in the laryngopharynx were mainly consisted of secondary lymphoid follicles encapsulated by connective tissue. The stratified squamous epithelia covering the tonsils and their crypts were frequently heavily infiltrated by lymphoid cells. The pharyngeal and tubal tonsils (TT) were situated in the nasopharyngeal tract. The cells of the pseudostratified columnar epithelia of the pharyngeal and TT were loosely connected, with large intercellular space. They consisted of scattered lymphoid follicles, aggregations of lymphoid cells and diffuse lymphoid tissues. Many high endothelial venules, specialized for the diapedesis of lymphoid cells into the tonsillar tissue, were detected in the four porcine tonsils. Therefore, the overall structures of the tonsils (the tonsil of the soft palate, the paraepiglottic tonsil, the pharyngeal and the TT) reflect their immune functionality in the oral and intranasal immunity.

Ultramicroscopic examination of the ovine tonsillar epithelia.

As solid morphological knowledge of ovine tonsillar epithelia might contribute to a better understanding of the pathogenesis of several diseases including prion diseases, the epithelia of all tonsils of 7 one-year-old Texel sheep were examined using scanning and transmission electron microscopy. Major parts of the pharyngeal and tubal tonsils were covered by pseudostratified columnar ciliated epithelia that were interrupted by patches of epithelium containing cells with densely packed microfolds or microvilli, and cells with both microvilli and cilia. Smaller parts were covered by either flattened polygonal cells with densely packed microvilli or microfolds, squamous epithelial cells, or patches of reticular epithelium. The palatine and paraepiglottic tonsils were mainly lined by squamous epithelial cells with apical microplicae or short knobs. Additionally, regions of reticular epithelium containing epithelial cells with apical microvilli were seen. The lingual tonsil was uniformly covered by a keratinized squamous epithelium and devoid of microvillous cells and patches of reticular epithelium. The rostral half of the tonsil of the soft palate was lined by a pseudostratified columnar ciliated epithelium with characteristics of the pharyngeal and tubal tonsils. The epithelium of the caudal part resembled the epithelia of the palatine and paraepiglottic tonsils. Putative M cells, mainly characterized by apical microvilli or microfolds and a close association with lymphoid cells, seem manifestly present on the nasopharyngeal tonsils. The reticular epithelium of the palatine and paraepiglottic tonsils also harbor cells with small apical microvilli. The exact nature of these presumptive M cells should, however, be elucidated in functional studies.

Evolution and development of immunological structures in the lamprey.

Comparative immunology has been revitalized by the integration of genomics approaches, which allow a foothold into addressing problems that previously had been difficult to study. One such problem had been the enigmatic finding of overt immune anatomical structures in the lamprey, yet its apparent lack of bona fide immunoglobulin or T cell receptor molecules. The genomic characterization of a novel extended locus that undergoes rearrangements to generate receptor diversity and the subsequent implementation of this diversity in the immune system of lampreys have generated considerable interest as well as new avenues for investigation. Here, we review the anatomical structures of the lamprey that exhibit lympho-hematopoietic characteristics, with the ultimate goal of reconciling these data with contemporary molecular findings. By integrating these datasets we seek to better understand how an alternative adaptive immune system could have evolved.

Making sense of molecular signatures in the immune system.

The development of Functional Genomics technologies has opened new avenues to investigate the complexity of the immune system. Microarray technology has been particularly successful because of its relatively low cost and high genome coverage. Consequently to our ability to monitor the expression of a significant proportion of an organism genome, our understanding of the molecular dynamics behind cell differentiation and cell response has greatly improved. Molecular signatures associated to immune cells have provided important tools to investigate the molecular basis of diseases and have been often associated to diagnostic and prognostic markers. The availability of such large collection of data has stimulated the application of complex machine learning techniques in the attempt to link molecular signatures and cell physiology. Here we review the most recent developments in the analysis of molecular signatures in the immune system.

[Research of ultra-structural pathological changes of nervous, endocrine and immune system in heroin addicts].

OBJECTIVE: To investigate ultrastructural pathological changes of Heroin-Addicts. METHODS: Heroin-Addicts' central nervous system, endocrine system, immune system and reproductive system in 4 cases are observed by using transmission electron microscope(TEM). RESULTS: The changes of central nervous system are mitochondrion swelling, crista fragmentation and disappear. Endoplasmic reticulum dilation, nervous fibres and cell organelles reduction; mitochondrion swelling, Partial crista fragmentation and endoplasmic reticulum dilation are also found in endocrine system; Lymphocytes reduction, cytoplasm ingredient reduction and dead lymphocytes increase in immune system; in reproductive system, spermatogenic cells and cell organelles are reduced in the male and follicle disappeared in the female. CONCLUSION: Ultra-structural pathological changes of heroin-addicts are presented acute, chronic oxygen deficiency degeneration and necrosis.

Anatomy of the immune system: facts and problems.

In the introductory section of this report, the anatomy of the immune system, from organs and tissues to molecules, will be reviewed briefly. Cell proliferation and differentiation in the central lymphoid organs (thymus and bone marrow) yield a repertoire of T- and B-cell clones that seed into peripheral lymphoid organs (spleen, lymph nodes and Mucosa-Associated Lymphoid Tissue, MALT), where humoral and cell-mediated antigen-specific immune responses occur. The stringent process of clonal selection in the central lymphoid organs implies deletion of inappropriate cells via apoptosis. In the peripheral lymphoid organs, the potential of unlimited activation and expansion of lymphocytes in response to antigens is primarily regulated by apoptosis and anergy. These events, on the one hand, are relevant to prevent autoimmunity and lymphoproliferative disorders; on the other hand, clonal deletion and anergy provide a detrimental escape to immune recognition of malignant cells. Two major inhibitory mechanisms of the immune response have emerged recently. One is linked to the existence of bona fide suppressor cells and cytokines; the other relies on the existence of inhibitory molecules expressed by T, B and NK cells, as well as by other leukocytes. In the studies herein reported, emphasis will be given to surface membrane molecules that down-regulate T-cell-mediated immune responses. These molecules control interactions between T cells and antigen presenting cells (APC's) or target (virus-infected or mutated) cells that have to be killed. Two sets of molecules exist that either upregulate (coactivation molecules) or down-regulate (inhibitory molecules) T-cell mediated responses. The latter aspect of the immune regulation, i.e. molecules that limit the expansion of T-cell clones following specific recognition of antigens will be considered in depth. Two inhibitory molecules, CD152 (CTLA-4) and CD85/LIR-1/ILT2 are expressed in all T cells, being largely confined within intracellular compartments of these lymphocytes when they are in a resting state, but ready to be shuttled to and from the plasma membrane when cells are activated following encounter with antigen. Membrane expression of the two inhibitory molecules is transient and is regulated by an internalization process directed to endosomal compartments and to receptor degradation and/or recycling. CTLA-4 and CD85/LIR-1/ILT2 play a pivotal role in T-cell homeostasis that follows any cell-mediated immune response; their localization and functional role will be thoroughly analyzed. In the last part of this study a major question will be faced, i.e. is the containment of the possibly unlimited expansion of the immune system due to a blockade of the cell cycle? Or, else, could be apoptosis the sole mechanism responsible? Experimental data in support of the latter contention will be provided.

[The effect of immunomudulin on the structural-functional status of the organs of the immune and hematopoietic systems in chronic toxic hepatitis]. / Vliianie immunomodulina na strukturno-funktsional'noe sostoianie organov immunnoi i krovetvornoi sistem v usloviiakh khronicheskogo toksicheskogo gepatita.

Long-term entry of the hepatotropic poison heliotropin induces the development of chronic active hepatitis attended with disturbance of the immune balance and hematologic disorders in it. Immunomodulin alleviates the destructive changes in the organs of the immune system, stimulates proliferation and differentiation of their cells, and promotes restoration of red blood parameters. It is suggested that immunoglobulin may be a promising measure in complex treatment of chronic liver diseases.

Luteinizing hormone-releasing hormone (LHRH) receptors in the neuroendocrine-immune network. Biochemical bases and implications for reproductive physiopathology.

It seems apparent that the brain-pituitary-reproductive axis and the brain-thymus-lymphoid axis are linked by an array of internal mechanisms of communication that use similar signals (neurotransmitters, peptides, growth factors, hormones) acting on similar recognition targets. Moreover, such communication networks form the basis and control of each step and every level of reproductive physiology. This work has focused on the LHRH system, a primary central and peripheral clock of both neuroendocrine and immune functions. From the initiation of a sexually organized response, the detection of sexual odors, and the induction of mating behavior, extrahypothalamic and hypothalamic LHRH orchestrates the neuroendocrine modulation of gonadotropin secretion, while its expression within the ovary directly controls specific events such as follicular atresia. The presence of LHRH receptors in oocytes clearly anticipates a potential action of the decapeptide during the process of fertilization and/or implantation. Within the thymus and other peripheral immune organs, LHRH plays a unique role of immunomodulator, contributing to the sex-dependent changes in immune responsiveness during the estrous-menstrual cycle as well as pregnancy. The reciprocity of the neuroendocrine-immune signaling systems is further supported by the ability of sex steroids to modulate thymus-dependent immune functions via direct effects on specific target genes involved in the development of sex dimorphism and sex-dimorphic immune responses, including the downregulation of immune response observed during pregnancy. Such cyclic changes in immune responsiveness could have a physiological implication, such as the decrease or suppression in cell-mediated immunity observed in the postovulatory phase of the cycle and in pregnancy, respectively, and might play a role during the implantation process and the establishment of pregnancy. In this context, the ability of corticosterone to directly inhibit both GR transcript levels as well as a cell-mediated immune response within the thymus, and the modulation of such an inhibitory effect by the sex steroid hormone milieu, may offer an explanation and a molecular mechanism whereby stress may be deleterious for reproduction, also via immunomodulation. On the other hand, hormonally mediated alterations in immunity might also have a pathological implication in sexually related immune diseases. For example, in mouse and humans, lupus erythematosus is more prevalent in females and estrogen accelerates the disease process, while menstruation is known to exacerbate idiopathic thrombocytopenia purpura. Sex steroid hormone milieu might also have a role in controlling the stress response through immunomodulation. Within the placenta, an intricate network of signaling systems controls a delicate interplay between the neuroendocrine hormones, growth factors, and cytokines that are susceptible to play a major local role in the processes of implantation and the establishment and completion of pregnancy. The neuroendocrine and immunomodulatory role of LHRH continues well after parturition because the presence of LHRH-like material within the mammary gland and milk participates in the physiological modulation of hypophyseal, gonadal, and immune functions of the pups. Such a significant role played by the hypothalamic peptide in the modulation of immune responsiveness would indicate LHRH as the signal conveying information to both neuroendocrine and immune cells, with the role of informing and then transducing the messages into appropriate biological responses.(ABSTRACT TRUNCATED)

[The function of the immune, reproductive and endocrine body systems during irradiation under exposure to stress factors of a non-radiation nature]. / Sostoianie immunnoi, reproduktivnoi i éndokrinnoi sistem organizma pri obluchenii v usloviiakh vozdeistviia stress-faktorov neradiatsionnoi prirody.

Diverse indexes of the state of immune, reproductive and endocrine systems were studied by morphological, biomechanical and biological methods under the effect of non-radiation stress factors, accompanying irradiation of the animals and their changes under effect of the ionizing irradiation 7 and 360 sGy in doze. It was demonstrated that short-time extreme effect lead to hormonal homeostasis destabilization, compensatory-adaptive transformations in immune system and also influence the indexes of copulation efficiency and intrauterine losses. Ionizing irradiation modifies the response to stress-factors effect with modification depending on the irradiation doze.

Scanning electron microscopic observations of the immunodefensive systems with special reference to the surface morphology of the non-lymphoid cells.

This paper reviews scanning electron microscopic observations of cellular elements forming various lymphoid organs. The reticular cells in the secondary lymphoid organs are stellate, smooth-surfaced forms extending slender processes to comprise a three-dimensional network. The reticular fibers are usually covered by reticular cell processes, though they are naked in certain regions. Other types of reticular cells are observed in certain places: the "retothelial" type in the lymphatic sinus of the lymph nodes, and the "follicular dendritic" type in the germinal center of various lymphoid organs. The thymic epithelial cells are divided into two main types: stellate cells which form a three-dimensional meshwork throughout the thymus parenchyma; and large vacuolated cells located in the medulla. A continuous single layer consisting of the processes of the stellate epithelial cells separates the parenchyma from the connective tissues of the capsule, septa and vessels. The M cells in the epithelium of the gut-associated lymphoid tissues (GALTs) are cells with numerous irregular microprojections on the luminal surface. They often attach microorganisms to the luminal surface, reflecting their functions of antigen transport into the underlying lymphoid tissue. Lymphocytes of various shapes often cluster in the intercellular spaces under the M cells, a phenomenon believed to indicate direct stimulation of lymphocytes by certain transported substances. Macrophages are amoeboid cells independent of and unable to transform into reticular and endothelial cells, at variance with prerequisites of the reticulo-endothelial system concept. Multiple features of macrophages probably reflect the presence of the subpopulations as well as the phases of their activity.(ABSTRACT TRUNCATED AT 250 WORDS)

[An electron microscopic study of the effector link in immune reactions in stomach cancer]. / Elektronno-mikroskopicheskoe izuchenie éffektornogo zvena immunnykh reaktsii pri rake zheludka.

21 surgically removed gastric carcinomas of different histologic structure and stage of development were studied ultrastructurally. A variety of morphological manifestations of local immune reactions and nonspecific antitumour resistance were observed. These manifestations were characterized by the contacts of lymphocytes, macrophages, polymorphonuclear leukocytes, plasma cells with each other and with tumour cells and by the presence of variable changes in tumour cells. The causes of such a variety are discussed and they may be due to different types of cytotoxicity, stage of the interaction between the effector and the target and so on.

Close relationships between the cells of the immune system and the epithelial cells in the rat small intestine.

A possible contribution of the intestinal epithelium to the immune defense system was studied by electron microscopy in the rat small intestine. The cells of the immune system (CIS) such as lymphocytes, eosinophils and macrophages penetrate the basal lamina into the epithelium and make close relationships with the absorptive cells. At the points of close apposition, the two cell membranes run parallel at a regular distance of about 20 nm. On the other hand, about 5% of the intestinal absorptive cells also penetrate the basal lamina into the lamina propria via their basal protrusions and show a similar close association with CIS. The basal protrusions contain many microfilaments; this indicates that they are structures with a definite function rather than a simple hernia. These findings are discussed with respect to the transport of antigenic molecules and of intercellular communication between CIS and the intestinal epithelium.

Morphological alterations in the lymphoreticular system in acquired immunodeficiency syndrome.

Acquired immunodeficiency syndrome (AIDS) manifests a profound deficiency in cellular and humoral immunity causing opportunistic infections with high mortality. Intensive searching for accurate diagnosis, effective treatment, and reliable preventions are in progress. Diagnostic findings include lymphocytopenia, decreased T-helper/T-suppressor ratio and antibodies against human T-lymphotropic retrovirus-III. Specific morphological markers for the diagnosis of AIDS are not yet available at this time. Consistent findings in the lymphoreticular system include a reactive hyperplasia in the onset to lymphocyte depletion in it's advance stage. The frequently mentioned ultrastructural changes in lymphoreticular cells are tubulo-reticular structures, test tube and ring-shaped forms, multivesicular and virus-like particles. These are, however, nonspecific for the diagnosis of AIDS.

Cellular elements of the immune system in the larynx cancer, SEM study.

Observations that certain primary tumors (solid ones) are infiltrated by cells which participate in immune responses tend us to examine this problem in spontaneously growing larynx carcinoma (ca. planoepitheliale). Our observations in SEM revealed within but also in surrounding of cancer infiltrations the presence of cellular elements belonging to the immune system like: lymphocytes, monocytes and macrophages. The most numerous of them, lymphocytes, are brought to the surrounding and tumor's territory by very rich vascular network (angiogenesis phenomenon). Bidirectional transmigration of the lymphocytes, observed mainly within the postcapillary venules, takes place through the cytoplasm of endothelial cells. It is most probably that they are lymphocytes of T-type which are involved in a cell mediated mechanisms of the immune response against a tumor. The lymphocytes are responsible also for the presence of monocytes and especially macrophages within a tumor's territory. These facts suggest that the human organism, in certain degree, is able to fight against malignant tissue by similar mechanisms which are involved in the rejection of the graft.