Effect of zinc chloride on hamster lymphoid cells: mitogenicity and differential enhancement of lipopolysaccharide stimulation of lymphocytes.

ZnCl2 over a very narrow concentration range was found to be mitogenic for hamster lymph node cells but not for thymocytes or splenocytes. Maximal leucine, [3H]uridine, and [3H]thymidine incorporation. Addition of 10 micron ZnCl2 was found to greatly enhance the stimulation observed with the B-lymphocyte mitogen lipopolysaccharide but not with dextran sulfate or the T-lymphocyte mitogen lipopolysaccharide but not with dextran sulfate or the T-lymphocyte mitogen concanavalin A. Although not mitogenic for splenocytes, 10 to 25 micron ZnCl2 slightly enhanced lipopolysaccharide stimulation but not concanavalin A or dextran sulfate stimulation. The effect of ZnCl2 on lipopolysaccharide stimulation was also confirmed with outbred Hartley guinea pig splenocytes and lymph node cells. Zinc chloride (50 micron) was mitogenic for both of these tissues; the response to lipopolysaccharide was enhanced by addition of 50 micron ZnCl2, but the concanavalin A response was unaffected. The possibility that the zinc effect is mediated by proteolytic mechanisms is discussed.     

Monocyte-dependent stimulation of human T cells by zinc.

Subpopulations of human peripheral blood leucocytes were isolated by nylon filtration or E-rosette separation and tested for functional activity. As shown previously, zinc ions induce DNA synthesis in unfractionated lymphocyte cultures. E-rosette-forming cells (E-RFC), obtained either by nylon wool filtration or E-rosette separation, responded well to PHA but showed only low levels of proliferative reactivity to zinc and Con A. These dminished responses could be completely restored by the addition of small numbers of autologous, mitomycin-treated monocytes; further experiments suggested that a monocyte-derived soluble factor can substitute for monocytes in this function. B lymphocyte-enriched cell populations, containing less than 1% E-RFC, did not respond to zinc and showed only marginal reactivity to PHA and Con A.     

Direct stimulation of lymphoid tissue of the chicken. II. Changes in lymphoid organs following intrathymic and intravenous injection of antigen

Lymphoid tissue from chickens immunized intrathymically or intravenously with BSA was examined histologically at various time intervals after challenge. Quantitative analyses of the thymus medulla and the periarterial area of the spleen were based on 4080 to 6942 counted cells. Three days after immunization, thymic lobes injected with BSA exhibited an increase in the number of blasts. This was followed by a rise in plasma cell population up to 5 days. Significant diminution of small lymphocytes and moderate increase of medium and large lymphocytes occurred after immunization. Contralateral noninjected thymic lobes of the same chickens showed similar cellular kinetics. In thymuses of birds immunized intravenously with BSA there was a moderate increase in plasma cells. Thymic lobes of intrathymically or intravenously immunized bursectomized chickens were normal. In the spleen, an augmented number of blasts was found 3 days after intrathymic or intravenous challenge. Intrathymic injection of BSA produced profound changes in the bursal follicles and intense plasmacytic reaction 3 and 9 days after immunization. The results are discussed in the light of the hypothesis that the chicken thymus is not only a primary lymphoid organ, but also an organ capable of acting as a secondary lymphoid tissue.     

Direct stimulation of lymphoid tissue of the chicken. 3. Haemagglutinin production, haemolysin-forming cells and changes in lymphoid tissues following injection of guinea-pig erythrocytes into the bone marrow

The hypothesis that the avian bone marrow is a site of actual antibody production has been experimentally verified in this study. Normal and neonatally bursectomized 8-week-old White Rock chickens were injected with guinea-pig red blood cells into the left femoral marrow or into the wing vein. The intramarrow administration of antigen proved to be as effective as the intravenous injection in inducing the production of haemagglutinins and antibody plaque response of 19S class. An important finding was that White Rock bursaless chickens were capable of synthesizing considerable amount of circulating 19S agglutinin after a single challenge with guinea-pig erythrocytes. There was a significant proliferation of plaque-forming cells in the spleen and bone marrow of normal immunized chickens.Quantitative cytological analysis revealed that an increase in the number of small and immature lymphocytes preceded the appearance of cells of the plasmacytic series in both antigen-injected marrow and contralateral non-injected marrow. The thymus and bursa did not exhibit apparent changes. This study provides strong evidence that chicken bone marrow may act in antibody production as a secondary lymphatic tissue. The results are discussed with respect to the interaction between thymus-derived, bursa-derived and bone marrow-derived cells in humoral immunity of the chicken.     

Alterations in the protein synthetic apparatus of cells infected with herpes simplex virus.

The effect of infection with herpes simplex virus (HSV) on the rate of protein synthesis, the distribution of ribosomes, and the time required to complete nascent peptides (transit time) in either actively growing or stationary phase Vero cells was examined. It was shown that the rate of protein synthesis per polysomal ribosome decreased continuously throughout the early portion of the infection cycle. This occurred despite an increase in the accumulation of ribosomes in polysome-like structures that accompanies the onset of synthesis of HSV-specified proteins. Transit-time measurements demonstrated that the rate of polypeptide elongation was not altered after infection. These data are discussed in light of a model that suggests that polysome-like structures are present but not functioning (or functioning very poorly) in HSV infected-cells.     

Alterations in somatostatin cells and biochemical parameters following zinc supplementation in gastrointestinal tissue of streptozotocin-induced diabetic rats

Chronic hyperglycemia in diabetes is a major causative factor of free radical generation which further leads to many secondary diabetic complications via the damage to cellular proteins, membrane lipids, and nucleic acids. Zinc is an essential trace element in all living systems and plays a structural role in many proteins and enzymes. Somatostatin is known to have inhibitory effects on various gastrointestinal functions. Therefore, we determined somatostatin protein production and secretion levels, and biochemical and light microscopical changes following zinc supplementation in the gastrointestinal tract of streptozotocin (STZ)-diabetic rats. The animals were divided into four groups: Group I: control (untreated) animals; Group II: control animals given zinc sulfate; Group III: diabetic animals; and Group IV: diabetic animals given zinc sulfate. Zinc sulfate was given to the animals by gavage at a daily dose of 100 mg/kg body weight for 60 days. Diabetes was induced by intraperitoneal (i.p.) injection of STZ in a single dose of 65 mg/kg. For histological studies, stomach and duodenum tissues were fixed in Bouin solution and sections stained with Masson's trichrome and Periodic-Acid-Schiff. Tissue homogenates were used for protein, lipid peroxidation (LPO), glutathione (GSH), and nonenzymatic glycosylation (NEG) analyses. Zinc supplementation to the STZ-diabetic rats revealed the protective effect of zinc on these parameters. Zinc supplementation may contribute to prevent at least some complications of diabetes mellitus.     

Warthin tumor. B-lymphocytes within the lymphoid infiltrate.

The lymphoid stroma in Warthin tumor is predominantly composed of complement receptor B-lymphocytes. These lymphocytes are present in a pattern similar to that observed in reactive lymph nodes. The B-lymphocytes may be residual lymph node elements exhibiting reactivity directed toward the epithelial component of the tumor.     

Circulating immune complexes in primary biliary cirrhosis: interactions with lymphoid cells

To evaluate the interactions between circulating immune complexes (CIC) and lymphoid cells in primary biliary cirrhosis (PBC), we determined (1) whether antibodies to lymphocytes in PBC serum, independent of CIC, could account for binding in the Raji cell assay for CIC and (2) whether CIC or other humoral factors in PBC serum could interact with lymphoid cells to alter their function. We found that three quarters of CIC positive PBC sera bound specifically to Raji cells via complement receptors, while only one quarter had antibodies to lymphoid cells or Raji cells devoid of complement receptors. We also demonstrated factors which inhibited cell-mediated cytotoxicity and suppressor cell activity in PBC sera; however, we found no correlation between the level and presence of CIC or of lymphocyte antibodies and the level or presence of these serum inhibitory factors. Thus, although the detection of CIC in PBC is not artifactual, the contribution of CIC and other serum factors to the other immunological aberrations in PBC remains to be elucidated.     

人外周血卡介苗(BCG)特异性中央型和效应型记忆CD4+T细胞的特征

目的：探讨正常人外周血BCG特异性记忆T细胞的特征。方法：分离PPD^-和PPD^＋正常人PBMCs，与BCG进行培养，采用ELISA法检测细胞培养上清液中IFN-γ的水平，ELISPOT法检测分泌IFN-γ的细胞数，利用流式细胞仪在单个细胞水平上检测细胞表面分子及细胞内因子IFN-γ和IL-2的表达及其关系。结果：当BCG刺激后，PPD^＋正常人PBMCs不产生或只产生少量的IFN-γ，而PPD^＋者IFN-γ产生的量和细胞数均明显增加（P〈0．05）。流式细胞检测分析的结果表明，当BCG刺激后，主要是CD4^-而非CD8^＋T细胞表达IFN-γ和IL-2，两者相比具有显著差异。在CD4^＋T细胞中单独产生IFN-γ的细胞占大多数，其次为IFN-γ和IL-2双阳性细胞，只产生IL-2的细胞占少数。此外，85％～95％以上的CD4^＋IFN-γ^＋T细胞为CD45RO^＋，其中60％以上的细胞为CCR7^＋，其余的为CCR7^-。同样地，80％～95％左右的细胞为CD62L。。结论：BCG可以诱导抗原特异性记忆CD4^＋T细胞的产生，其中大多数为中央型记忆CD4^＋T细胞，少数为效应记忆CD4^＋T细胞，提示其在预防和控制结核分枝杆菌感染中发挥重要作用。     

Alterations of the thymus and other lymphoid tissue in young horses with combined immunodeficiency.

Combined immunodeficiency (CID) is a significant disease in terms of prevalence in Arabian foals and is a useful animal for study of a similar condition in children. Thymuses from all CID foals examined were extremely hypoplastic. Light and electron microscopic examination of thymuses from CID foals, as well as a thymus from an aborted CID fetus, demonstrate that the basic thymic structure is intact, despite a number of dissimilar morphologic appearances. From these data, we inferred that the thymic hypoplasia was caused by a failure of committed lymphocytes from the bone marrow to populate the organ. The lack of uniform organized lymphocytes in the spleen and lymph nodes provides considerable support for the absence of lymphoid precursors or their inability to respond to differentiating influences.     

c-Fos protein expression in the rat subfornical organ following osmotic stimulation.

To examine the role of the subfornical organ (SFO) in the osmotic activation of hypothalamic neurons, the responses of the SFO to osmotic stimulation were evaluated by using c-Fos protein immunohistochemistry. Numerous c-Fos-immunoreactive nuclei were found in the SFO of rats injected i.p. with hypertonic saline solution as early as 30 min after stimulation, and the effect lasted up to 3 h. Only a few c-Fos-positive cells were detected in the SFO of rats injected with isotonic saline. However, electrolytic lesions of the SFO did not prevent the osmotic activation of the hypothalamic paraventricular and supraoptic nuclei. These data suggest that the SFO and the hypothalamic magnocellular nuclei are simultaneously but separately activated by osmotic stress.     

Mitogenic stimulation of mouse lymphoid cells by Aleuria aurantia agglutinin

An investigation was undertaken to determine if an agglutinin isolated from Aleuria aurantia possesses a mitogenic activity. Proliferation response of mouse lymphoid cell cultures was measured by 3H-thymidine uptake. The results revealed that Aleuria aurantia agglutinin at the concentration of 1 microgram/ml is mitogenic for Thy-1+ splenocytes and cortisone-resistant thymocytes.     

Plaque-forming cells in rabbits following stimulation of the appendix with sheep erythrocytes

Sheep erythrocyte (SRBC) antigen was delivered directly into the lymphoid component of the appendix or via the appendicular artery, followed by ligation or clamping of appendicular vessels. Antigen was also injected intravenously, into the spleen, or into the thymus. Counts of anti-SRBC plaque-forming cells (PFC) in the appendix were compared with counts in the spleen and thymus. None of the injection routes employed resulted in an elevation of PFC activity above background in the appendix. However, delivery of antigen via the appendicular artery caused a marked increase of PFC activity in the spleen. These results and other available evidence point towards a helper-cell function of lymphocytes in the appendix, and therefore suggest a central role of this organ in humoral immunity.     

Alterations in intracellular calcium following infection of human endothelial cells with Trypanosoma cruzi

Trypanosoma cruzi infection in cultured human umbilical vein endothelial cells increased basal cellular calcium levels from 55 to 110 nM, as monitored with the fluorescent probe, fura-2. It also influenced intracellular calcium such that consistently higher total levels were observed in response to bradykinin, angiotensin II and norepinephrine, as compared to similarly treated uninfected cells. However, bradykinin and angiotensin II-dependent increases in calcium, when considered as the absolute increment or fold elevation over basal, were significantly lower in infected endothelial cells. Infection also influenced changes in calcium levels due to agents that operate independently of plasma membrane receptors. In the presence of ionomycin, the magnitude and rate of rise of intracellular calcium were decreased; additionally the calcium peak was delayed and the subsequent decline slowed. Similar to the results with bradykinin and angiotensin II, infection decreased both the increment in and fold stimulation of intracellular calcium in response to ionomycin. In contrast, infection altered only the total calcium stimulated in response to oligomycin; neither the fold stimulation of, nor increment in intracellular calcium was affected. These results indicate that (1) infection by T. cruzi alters calcium homeostasis in endothelial cells under basal and stimulated conditions; (2) both receptor-dependent and receptor-independent mechanisms are affected by infection. The possible contribution of altered calcium homeostasis induced by T. cruzi in the pathogenesis of chagasic cardiomyopathy is considered.     

Alterations of pulmonary zinc homeostasis and cytokine production following traumatic brain injury in rats

Previous studies have shown that labile zinc and inflammatory mediators participate in many pathophysiological processes. The present study investigated the effects of traumatic brain injury (TBI) on the levels of labile zinc and certain proinflammatory factors in rat lung. Male Wistar rats were randomly assigned to 7 groups as follows: normal group, group with sham operation, and TBI groups that were sacrificed respectively at 1, 6, 24, and 72 hr, and on day 7 post-injury. Pulmonary labile zinc, tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-8, and wet/dry weight ratio were measured at the specified time intervals. TBI caused a gradual increase of pulmonary labile zinc as demonstrated by fluorescence staining with Zinpyr-4 (ZP4). The levels of TNF-alpha and IL-8 and the lung wet/dry weight ratios were higher in the TBI groups compared to the normal and sham-operated groups (p <0.05). There were highly positive correlations between the intensity of ZP4 fluorescence and the pulmonary levels of TNF-alpha and IL-8. The results suggest that TBI induces rapid increases of labile zinc and inflammatory mediators in lung, which may participate in the pathogenesis of acute lung injury.     

Serum-free culture of hamster lymphoid cells and differential inhibition of lipopolysaccharide stimulation by isologous serum.

The optimal conditions for serum-free cultures of hamster lymphoid cells were determined. The cells responded to both the nonspecific thymus-derived lymphocyte mitogen concanavalin A (Con A) and the nonspecific bone marrow-derived lymphocyte mitogens lipopolysaccharide (LPS) and dextran sulfate (DxS). Normal MHA hamster serum was shown to specifically inhibit the response to LPS and DxS by 95% without inhibiting the response to Con A. The serum also did not inhibit one-way mixed lymphocyte reaction. Incubation of cells in 5% serum for short periods of time, followed by serum-free culture, did not lead to inhibition. The serum inhibited the LPS response by 65% even when added 24 h after initiation of the culture. The activity was associated with the high-molecular-weight material on Sephadex G-200 fractionation of serum. The inhibitory fraction did not possess antibody activity to LPS. The possibility that the material is an alpha2-macroglobulin is discussed.     

Induction of haemolytic plaque-forming cells with sheep lymphoid cells in vitro.

The in vitro induction of specific primary and secondary immune responses in sheep lymph node cell suspensions is described and suitable culture conditions determined. The induction of primary immune responses required supplementation of the culture medium with antigen-absorbed homologous serum or lymph, whereas the requirements for the induction of a secondary response were less stringent. The addition of 2-mercaptoethanol to the medium was required. The amounts of heterologous erythrocytes used for immunization were critical and optimal responses were obtained when 50 microleters of a 1% suspension were added to 1 ml cultures. Lymphocyte densities of about 5 X 10(6)/ml were found optimal in primary immune responses in vitro. Less than 2 X 10(6) cells/ml rarely gave rise to plaque-forming cell (PFC) generation, whereas densities of 10 x 10(6) and above reduced the number of PFC obtained per number of cultured cells. Lymphocytes obtained from the efferent lymph draining lymph nodes previously immunized with heterologous erythrocytes were found to generate PFC in vitro when specific antigen was added to the cultures, but attempts to generate PFC in vitro with cells from efferent lymph draining non-immunized nodes failed.     

The detection and characterization of a membrane protein with Factor B-like activity on human lymphoid cells.

Factor B-like activity associated with human peripheral blood lymphocytes was first described by Halbwachs & Lachmann (1976), who employed a functional assay. In this present study, clones of B cells from patients with chronic lymphatic leukaemia (CLL) and lymphoblastoid 'Raji' cells were used. The surface of these cells was labelled with 125I by the lactoperoxidase technique and the cell membrane proteins solubilized with the detergent NP40. A single polypeptide chain of molecular weight 103K was precipitated with F(ab')2 anti-serum Factor B, and not with a control antibody. This 103K protein was also found if Raji cells were biosynthetically labelled with [14C]-leucine. When the radiolabelled cells were incubated with cobra venom factor (CVF) and Factor D, two specific polypeptides were precipitated by F(ab')w anti-Factor B. Moreover, the larger fragment forms a complex with CVF, since it could be precipitated by anti-CVF. These events are similar to those involving serum Factor B and CVF.