Lymphomyeloid Organs Research Articles

Characterization of maternal immunity following vaccination of broodstock against IHNV or Flavobacterium psychrophilum in rainbow trout (Oncorhynchusmykiss)

Infectious hematopoietic necrosis (IHN) is a significant viral disease affecting salmonids, whereas Flavobacterium psychrophilum (Fp), the causative agent of bacterial coldwater disease (BCWD), remains one of the most significant bacterial pathogens of salmonids. We explored maternal immunity in the context of IHN and BCWD management in rainbow trout (Oncorhynchus mykiss) aquaculture. Two experimental trials were conducted where different groups of female broodstock were immunized prior to spawning with an IHNV DNA vaccine or a live attenuated F. psychrophilum (Fp B.17-ILM) vaccine alone, or in combination. Progeny were challenged with either a low or high dose of IHNV at 13 days post hatch (dph) and 32 dph or challenged with F. psychrophilum at 13 dph. Mortality following a low-dose IHNV challenge at 13 dph was significantly lower in progeny from vaccinated broodstock vs. unvaccinated broodstock, but no significant differences were observed at 32 dph. Mortality due to BCWD was also significantly reduced in 13 dph fry that originated from broodstock immunized with the Fp B.17-ILM vaccine. After vaccination broodstock developed specific or neutralizing antibodies respectively to F. psychrophilum and IHNV; however, antibody titers in eggs and fry were undetectable. In the eggs and fry mRNA transcripts of the complement components C3 and C5 were detected at much higher levels in progeny from vaccinated broodstock and showed a significantly increased and rapid response post-challenge compared with unvaccinated broodstock. After challenges pro-inflammatory cytokine expression was immediately and considerably elevated in the fry from vaccinated broodstock vs. unvaccinated broodstock, whereas adaptive immune genes were elevated to a lesser degree. Results suggest that maternal transfer of innate and adaptive factors at the transcript level occurred because development of lymphomyeloid organs is not complete in such young fry. In addition to documenting maternally derived immunity in teleosts, this study demonstrates that broodstock vaccination can confer some degree of protection to progeny against viral and bacterial pathogens.

ИММУНИТЕТ ПОЙКИЛОТЕРМНЫХ ГИДРОБИОНТОВ

The paper shows features of the immune system of poikilothermic aquatic organisms of different taxonomic groups: crustaceans, fish, and amphibians. Defense mechanisms of crustaceans are presented by largely innate non-specific factors: external covers (including the exoskeleton), mucus, physical and chemical barriers lysozyme in the hemolymph, propanolamine system, and phagocytosis. The authors identified 4 types of cells (hemocytes) found in the circulating fluid of crayfish, depending on the morphological and functional properties: agranulocytes, progranulin,granulocytes, and transparent cells. Each type performs different functions in the process of immune defense. In fish, there is no red bone marrow and lymph nodes, the main organs of hematopoiesis include thymus, spleen, liver, lymphoid tissue of the brain and the trunk of the kidneys,accumulation of lymphoid tissue of the cranial box, intestine, and pericardium. Humoral components of the immune response of fish are represented by immunoglobulins, system complement components, lysozyme, C-reactive protein, interferon, lysine, hemolysin, hemagglutinin. Only IgM-like antibodies represent immunoglobulins in fish. The central organ of the amphibian immune system is the red bone marrow, but its role in the immune defense of amphibians has not been sufficiently studied. Peripheral organs of the immune system include kidneys, thymus, spleen, lymphomyeloid organs. Depending on the characteristics of the immune system of poikilothermic hydrobionts of different types, the authors offer methods for assessing their humoralimmunity (by determining phenoloxidase) and cellular response (by phagocytosis). Cellular immunity, and phagocytic activity, in particular, can be evaluated using cytochemical methods taking into account oxygenindependent factors – the content of enzymatic lysosomal cationic protein in phagocytes – and oxygendependent ones – NBT-test with nitrosonium tetrazolium that records cytotoxic oxygen radicals generated during the respiratory explosion of cell stimulation in vitro.

Distribution of the professional phagocytic granulocytes of the bony fish gilthead seabream ( Sparus aurata L.) during the ontogeny of lymphomyeloid organs and pathogen entry sites

Although it is believed that fish fry depend fundamentally on their innate defence mechanisms, the ontogeny of fish innate immune cells is poorly understood. In the present study, we have used a specific monoclonal antibody against acidophilic granulocytes (AGs), the main professional phagocytic cell type of the bony fish gilthead seabream, to study their localization during the development of the main lymphomyeloid organs, namely the head kidney, spleen and thymus, and of the two major portals for pathogen entry, namely the gills and intestine. AGs were observed in the posterior intestine and in the blood earlier than in the haematopoietic kidney (21 vs. 27 days post-hatching, dph). AGs were observed scattered between other cells of the haematopoietic lineage in the head kidney of larvae, but were grouped around the blood vessels of this organ in juveniles and adults, where they were also much more numerous. In the spleen and in the thymus, AGs were observed much later (62 dph) and appeared scattered. AGs were also observed in the gill lamella and the posterior intestine near the anus throughout development.

Lymphomyeloid organs of the Antarctic fish Trematomus nicolai and Chionodraco hamatus (Teleostei: Notothenioidea): a comparative histological study

Lymphomyeloid organs of two common species of Antarctic fish, Trematomus nicolai and Chionodraco hamatus, were studied with the aim of analysing some morphological aspects of these organs in relation to adaptation to low environmental temperature. The thymuses of T. nicolai and C. hamatus were flattened, incompletely lobated, with numerous Hassall-like bodies, which were mainly located in the central part of the organ in C. hamatus. In T. nicolai, thymocytes, erythroid and reticular epithelial cells filled the organ. In C. hamatus, the thymocytes intermingled with reticular epithelial cells were often close to groups of melano-macrophages. In both species, the thymus did not show distinct compartmentalisation; however, the thymocytes had significantly different sizes in the outer and inner portions of the thymus. The head kidney of both species was completely filled by haematopoietic tissue, highly vascularised and mainly lymphopoietic in T. nicolai, while both erythropoietic and lymphopoietic in C. hamatus. The spleen appeared mainly erythropoietic in T. nicolai and mainly lymphopoietic in C. hamatus. Solitary melano-macrophages in T. nicolai were close to numerous small vascular ellipsoids where erythroid and lymphoid cells were intermingled without the formation of red and white pulp areas. In C. hamatus, large lymphoid areas were organised around the capillaries. The possible adaptation of lymphoid organs to the low temperature of polar water is discussed.

Histological observations on lymphomyeloid organs of the Antarctic fish Trematomus bernacchii (Teleostei: Nototheniidae)

Lymphomyeloid organs of the Antarctic fish Trematomus bernacchii were studied with the aim of analysing some morphological aspects related to adaptation to low environmental temperature. The thymus of T. bernacchii was flattened, incompletely lobated and scarcely regionalised. It was filled by lymphoid elements intermingled with stromal elements. The head kidney appeared highly vascularised and mainly lymphopoietic. The spleen appeared mainly erythropoietic, with scarcely developed areas of white pulp.

Induction of selective cell death targeting on mature T-lymphocytes in rats by a novel immunosuppressant, FTY720

A novel immunosuppressant, FTY720, induces a rapid and marked decrease of peripheral lymphocytes, and prolong allograft survival in rats. Its mechanism of action is mediated by apoptotic cell death. In this study, we determined the time-related changes in the numbers of total lymphocytes, and the ratios of lymphocyte subpopulations in peripheral blood and lymphomyeloid organs in rats after the single oral administration of FTY720 (10 mg/kg), comparing with the effects of cyclophosphamide (80 mg/kg, ip). Total number of peripheral lymphocytes decreased significantly 3 h after the administration of the drug, while that of polymorphonuclear cells increased. T-cells were markedly decreased in number and reached a minimum of 2.3% of the control 3 days after the treatment, while B-cells reached 19.7%. T-cells decreased in spleen and liver but there was no notable change in thymus, lymph nodes, and bone marrow. The susceptibility of the cells against the drug was variant based on the type and the source of cells in vitro. Polymorphonuclear cells were the most resistant and lymph node cells the most sensitive to FTY720 after 3 h incubation with different concentration of the drug (1, 10, 100 μmol/1). When incubated with 10 μmol/1 of FTY720, B-cells were significantly higher in viability than the whole T- or CD4-cells. These results demonstrated that FTY720 induces cell death selectively in mature T-lymphocytes, especially CD4-1ymphocytes, in peripheral blood without the depression of bone marrow.

Hibernation alters the frog's immune system

The lymphomyeloid organs and blood leukocyte populations of the leopard frog, Rana pipiens, undergo conspicuous changes during hibernation at 4 °C. Within the blood, spleen, thymus, jugular bodies, and bone marrow there was a progressive loss of hemopoietic populations resulting in a marked lymphocyte depletion. Termination of the 135-day hibernation period resulted in the restoration of all hemopoietic elements in the blood and lymphomyeloid organs within 30 days. Frogs subjected to experimental hibernation and immunized showed weakened immune responses when brought from the hibernaculum. Plaque-forming cells (PFC) were lower in spleen, jugular bodies, and bone marrow, and serum antibody titers were also lower. Although the kinetics of the primary responses were essentially the same, the secondary responses differed suggesting major rearrangements with respect to the numbers of cells and their function in secreting antibody. The apparent lymphocyte aplasia may contribute to the absence of immunological responsiveness during periods of hibernation.

THE CELLULAR STRUCTURE OF LYMPHOMYELOID TISSUES IN CHIMAERA MONSTROSA (PISCES, HOLOCEPHALI).

The ultrastructure of the main lymphomyeloid organs of the holocephalan fish, Chimaera monstrosa, is presented. The thymus is well developed even in adults. It is densely packed with small and large lymphocytes, the former predominating. The ultrastructure of C. monstrosa's lymphocytes is similar to that of mammalian ones. The lymphocytes show intimate connections with large epithelial reticulocytes, which infiltrate the cytoplasm of the lymphocytes with long processes. The lymphomyeloid tissues around the orbit are mainly granulocytopoietic. Two types of granulocytes occur: eosinophilic and heterophilic. The latter is found in excess. The granulocytes are ultrastructurally similar to those of elasmobranchs such as Etmopterus spinax and have similar characteristic granules. In addition to granulocytes in various stages, lymphocytes, plasma cells, blast cells, and solitary macrophages are scattered throughout the tissue. The suprapalatal region also has a similar supply and variety of cells, but most heterophilic granulocytes have modified granules. In the spleen, erythrocytes in different developmental stages are common. This confirms earlier studies which suggested that the spleen functions primarily as an erythrocytopoietic organ.

Decidual cell-specific surface antigen(s) recognized by monoclonal antibodies: tissue and species distribution.

Decidual cells are direct descendants of endometrial stromal cells and the ultimate progeny of bone marrow-derived precursors. In view of their bone marrow genealogy and demonstrated immunoregulatory role during pregnancy, this study attempted to identify a lineage-specific differentiation marker(s) on murine decidual cells with the hope of tracing their developmental pathway and exploring their familial relationship to other lymphomyeloid cells. Two protein A-binding, IgG2b isotype monoclonal antibodies (secreted by clones 16F12 and 2G4F8) were raised by immunizing virgin CBA mice with syngeneic decidual cells. The presence and the density of the antigenic marker(s) recognized by these antibodies were examined by radioautography on various cell types in single cell suspensions of the decidua, placenta, and lymphomyeloid organs after a sandwich labeling with hybridoma supernatants followed by 125I-protein A. Both antibodies appeared to recognize antigen(s) unique for the decidual cell lineage in mice, humans, and rats. The incidence of antigen-bearing decidual cells increased with gestational age in CBA, C3H, and CD1 mice between days 8 and 14, and in humans between 6 and 10.5 wk; in rats, however, some decline was noted between days 8 and 14. The binding was always higher with 16F12 than with 2G4F8 supernatants. No significant binding of either antibody to trophoblast cells of the placenta or leukocytes within the decidua was noted in any of the above mouse strains or species. Little or no labeling of any cell type was seen on lymphomyeloid cells of the virgin or pregnant CBA mice, but a consistent labeling of a rare blast-type cell in the blood was observed with both antibodies, raising the possibility that this cell may represent the circulating precursor of the decidual cell lineage. It remains to be investigated whether these antibodies are recognizing the same or different differentiation antigen(s) on the decidual cells, and whether a conservation of this antigen(s) during speciation signifies its functional importance.

Structural studies on lymphomyeloid tissues of the dogfish, Scyliorhinus canicula L.

The structure and ultrastructure of the lymphomyeloid epigonal and Leydig organs of the dogfish Scyliorhinus canicula L. were investigated. The tissues produce leucocytes, mainly granulocytic cells, but also some lymphocytes and plasma cells. Lymphocytes sometimes form nodule-like aggregations, especially in the epigonal organ. Granulocytes are probably stored within the lymphomyeloid tissues and enter the circulation on maturation. They may also release biologically active substances into the blood.

The alloantibody response in the allogeneically pregnant rat. III. The location of the alloantibody-forming cells.

We determined the location of alloantibody formation in the allogeneically pregnant rat. Greater than 95% of the alloantibody-forming cells were found in the spleen. A few were found in the paraaortic, renal, and parathymic lymph nodes. None were found in other lymphomyeloid organs. In addition, in vitro alloantibody synthesis was largely confined to splenic cells. We conclude that the alloantibody response in the allogeneically pregnant rat is largely peripheral to the uterus and to the lymph nodes that drain the uterus. Therefore, the alloantibody response in the allogeneically pregnant rat cannot be considered an example of a local immune response. In addition, we confirmed that the anti-paternal humoral response against RT1Aa caused by pregnancies by DA males differs dramatically from conventional and secondary pregnancy-induced alloimmunizations because the hierarchy of the number of alloplaques that are developed by these four methods of detecting alloplaques is different for primary pregnancy-induced responses as compared with conventional or secondary pregnancy-induced alloimmunizations.

Lymphoid Organs and Blood Cells of the CaecilianIchthyophis kohtaoensis

The present work analyzes by light microscopy circulating blood cells and lymphoid organs of the caecilian, ichthyophis kohtaoensis. Peripheral blood contains erythrocytes, thrombocytes, lymphocytes, monocytes, heterophils, easinophils and basophils. Thymus, liver and spleen are the major lymphomyeloid organs in this caecilian and there is not a haemopoietic functioning bone marrow. The results are discussed on the basis of the possible phylogenetic positions of the Apoda emphasizing their relationships to the Urodela.

Nucleic acid and protein synthesis in lymphomyeloid organs of testosterone treated embryos of the chicken ( Gallus domesticus)

1. (1) In normal 15–17 day old chickens embryos more DNA was synthesized in the spleen than the thymus. 2. (2) The pattern of RNA synthesis was: spleen > thymus and bursa. 3. (3) Protein biosynthesis was essentially the same in these organs. 4. (4) Administration of testosterone propionate (TP) by injection or dipping in ovo caused no change in biosynthesis of either nucleic acids or protein within organs. 5. (5) More DNA was synthesized in the spleen than the thymus or bursa in TP dipped or injected eggs. 6. (6) Treatment with TP changed the degree of labeling of small lymphocytes in a New Hampshire and small and medium lymphocytes in a White Leghorn strain.

Glycosidases in lymphomyeloid (hematopoietic) tissues of elasmobranch fish

Abstract 1. 1. High lysozyme and chitinase activities were found in Leydig's organ of Etmopterus spinax, Somniosus microcephalus and Torpedo nobiliana, in Leydig's and epigonal organs and spleen of Raja radiata, and in the epigonal organ of Rhinoptera bonasus. 2. 2. Strong chitinase activity with little or no lysozyme activity was noted in Leydig's and epigonal organs of Scyliorhinus canicula, and in the epigonal organ of Ginglymostoma cirratum and Heterodontus francisci. 3. 3. Very high β-N-acetylglucosaminidase activity was found in lymphomyeloid organs of all species investigated, and in the pancreas of Somniosus microcephalus. 4. 4. Thirteen other glycosidases were assayed in lymphomyeloid and digestive tissues of Ginglymostoma cirratum, Heterodontus francisci and Etmopterus spinax. Activities of α- d -mannosidase, β- d -galactosidase, β- d -N- acetylgalactosaminidase , β- d -glucuronidase and α- and β- d -glucosidase usually were higher in lymphomyeloid tissues than in digestive tissues.

Anti-brain antisera bind primarily to non-T cells in mouse bone marrow.

Anti-brain heteroantisera are widely employed for the delineation of T lymphocytes in lymphomyeloid organs despite compelling evidence demonstrating the cross reactivity of such reagents with unrelated hemopoietic cells. The experiments described in the paper utilized absorptions of a fluoresceinated goat anti-rat brain antiserum with thymocytes or nude bone marrow cells to determine the validity of using such an antiserum to identify T cells in the thymus, lymph nodes, spleen, and bone marrow of CBA/J mice. Thymocyte absorption of this fluoresceinated antiserum removed virtually all of the staining of thymus, lymph node, and spleen cells by this reagent. In contrast, the percentage of labeled marrow cells was unchanged by thymocyte absorption of the anti-rat brain antiserum, although the staining could be eliminated by absorption with nude bone marrow. These results suggest that anti-brain antisera can be employed as dependable T-cell probes with suspensions of the thymus or peripheral lymphoid organs. However, the vast majority of marrow cells staining with the anti-brain antisera are not T cells. Therefore, anti-brain antisera should not be utilized to discern T lymphocytes in this tissue unless additional absorptions (with nude marrow) or special controls are performed.

Size Relations of Lymphomyeloid Organs in Some Cartilaginous Fish

AbstractIn elasmobranchs (sharks, rays) the total weight of lymphomyeloid structures isolated by dissection varied between about 0.6 and 1.0% of the body weight. In a holocephalan (Chimaera) the corresponding value was 1.7%. Reciprocal size relations may exist between different types of lymphomyeloid organs. A thymus was found in adult specimens of rays (Raja) and the rabbit‐fish (Chimaera). The lymphomyeloid organs supposedly are active in haemopoiesis and the immune responses.

The distribution of rapidly and slowly renewed T, B, and “null” lymphocytes in mouse bone marrow, thymus, lymph nodes, and spleen

Combined radioautography and immunofluorescence were employed to discern the proportions of rapidly renewed (RR) and slowly renewed (SR) T, B, and null cells in mouse lymph nodes (LN), spleen (Spl), thymus (Thy), and the lymphocyte-rich fraction of bone marrow (BML). Thy and BML were found to consist predominantly of cells with a rapid turnover rate (95.4 and 76.9%, respectively) in accord with their roles as primary lymphoid organs. In contrast, the secondary lymphoid organs were primarily composed of SR cells (LN, 73.4%; Spl, 67.8%) and contained a more even admixture of the six lymphocyte subsets. Most cells in Thy were RR T cells (93.3%), whereas the predominant lymphocyte subpopulation in both LN and Spl consisted of SR T cells (56 and 50%, respectively), with RR T cells being much less frequent (14.6% LN; 6.8% Spl). BML contained both RR and SR cells which stained with the T-cell reagent (7.8 and 7.1%). These percentages are probably overestimates, however, since this reagent stained some nonlymphoid cells in BML. RR B cells were most plentiful in BML (31.4%) and Spl (23.3%), less common in LN (11.2%), and rare in Thy (0.4%). SR B cells were equally numerous in Spl (16%), LN (15.4%), and BML (15.3%). RR null cells were the most prevalent cell type in BML (37.7%), but were infrequent in other tissues (1.6% Thy, 2.1% LN, 2.1% Spl). SR null cells were rare in all tissues (0% Thy, 2% LN, 2.1% Spl, 0.7% BML). These experiments represent the first comprehensive investigation of the composition of the lymphomyeloid organs in terms of RR and SR T, B, and null cells. They conclusively demonstrate RR and SR lymphocytes in all three functional categories (T, B, and null) and show characteristic tissue distributions of the six lymphocyte subsets.

Kinetics of small lymphocytes in normal and nude mice after splenectomy.

Autoradiography and various quantitations on lymphoid tissues have been used to evaluate the kinetics of small lymphocytes in normal (+/nu or +/+) and congenitally athymic nude (nu/nu) NMRI mice 1 month after splenectomy or sham-splenectomy. The results indicate that splenectomy causes depressed thymic activity and diminished numbers of T lymphocytes in peripheral lymphoid tissues. The total number of cells in these tissues as well as the blast cell activity, were within normal limits. Bone marrow lymphocyte numbers and kinetics as well as blood lymphocyte levels in splenectomized and sham-splenectomized normal animals were comparable. Blood lymphocyte numbers were at normal levels in splenectomized nude mice, in spite of reduced numbers of bone marrow and thoracic duct lymphocytes. It is suggested that increased number of newly-formed lymphocytes, found in lymph nodes and blood of splenectomized mice, are released from the lympho-myeloid organs in compensation for the loss of long-lived, thymus-derived cells.

Thymic independence of the bone marrow lymphocyte phytohemagglutinin (PHA) response demonstrated in nude mice

The phytohemagglutinin (PHA) response of lymphocytes from the bone marrow and lymph nodes of athymic, nude mice and their normal littermates was studied using a sensitive microculture assay system. Whereas the lymph node PHA response was virtually absent in nude mice, the bone marrow lymphocyte response to this phytomitogen was undiminished in the athymic mice at all concentrations of PHA and all incubation periods. As shown on radioautographs, the responding cells were morphologically identical with PHA-responsive lymphocytes of normal marrow and lymph node. The possibility of mature T cell contamination of the nude mice was ruled out by the observation that the nature of the PHA response of the nude bone marrow was identical with that of normal bone marrow lymphocytes, but was distinct from that of normal lymph node cells. The studies unequivocally demonstrate that the bone marrow response to PHA is independent of the thymus. A hypothesis is discussed which suggests that precursor T cells are responsible for the bone marrow PHA response, whereas mature T cells are primarily involved in the response of other lymphomyeloid organs to this mitogen.

Surface immunoglobulins on Xenopus laevis lymphocytes

Abstract o 1. The surface immunoglobulins (Ig) on Xenopus laevis lymphocytes have been studied by immunofluorescence. 2. 60–85% of the lymphocytes in adult peripheral blood possess surface Ig. In post-Stage 48 tadpoles the proportion of such cells varies between 35 and 45%, the proportion rising to the adult level in the immediate post-metamorphosis period. 3. The proportions of surface Ig-carrying lymphocytes in the spleen and other lymphomyeloid organs are similar to those in the blood at any given developmental stage. The thymus is an exception: in tadpoles some 47–55%, and in metamorphs 70–75% of the thymocytes have surface Ig; this figure declines to between 8 and 12% in the adult. 4. In all situations the surface Ig appears to be almost exclusively IgM; IgG only presents on 5% or less of the cells. On no cells are both IgM and IgG present together. 5. The surface Ig can be capped, and can be removed by limited papain proteolysis of the cell surface: subsequent to capping or proteolysis the Ig is regenerated. 6. The phylogenetic significance of these results is discussed in terms of B and T cell delineation and differentiation.