Presence Of Mononuclear Cells Research Articles

The B cell dependence of Haemonchus contortus antigen-induced lymphocyte proliferation

The proliferative responses of ovine lymphocytes to soluble antigens of third-stage larvae of Haemonchus contortus (HcAg) were examined in vitro. Lymphocytes in mononuclear cell cultures responded consistently to HcAg even if the lambs were naive to H. contortus. Lymphocytes from sheep that were immune to reinfection with H. contortus also consistently responded to HcAg with a response significantly greater than that recorded from naive lambs. When the responses of T cell or B cell enriched fractions were examined, neither enriched cell population responded to HcAg, even though the T cell populations were shown to contain monocytes by histochemistry. Studies using the accessory cell dependent T cell mitogen Con A demonstrated that such T cell enriched populations had normal Con A-induced responses compared to unfractionated mononuclear cells. In addition, neither the T cell nor B cell fractions responded to HcAg in the presence of autologous mononuclear cells which contained monocytes and dendritic cells. Responses to HcAg in the T cell enriched population were restored, however, by the presence of mononuclear cells that were cultured with HcAg for 48 hours and then irradiated before the addition of the T cells. These results were seen with cells from both H. contortus naive lambs and immune sheep. This provides evidence that B cells and not dendritic cells or monocytes are acting as antigen presenting cells in Haemonchus antigen-induced lymphocyte responses in both naive lambs and immune sheep.

Lipopolysaccharides prime whole human blood and isolated neutrophils for the increased synthesis of 5-lipoxygenase products by enhancing arachidonic acid availability: involvement of the CD14 antigen.

Stimulation of heparinized blood with 1 microM formyl-methionyl-leucyl-phenylalanine (FMLP) resulted in the formation of < 30 pmol/ml plasma of 5-lipoxygenase (5-LO) products. The preincubation of blood with 1 microgram/ml of lipopolysaccharide (LPS) (Escherichia coli 0111-B4) for 30 min before stimulation with FMLP resulted in the accumulation of 250-300 pmol of 5-LO products per ml plasma. The major products detected were leukotriene B4 and (5S)-hydroxy-6,8,11,14-eicosatetraenoic acid which were produced in equivalent amounts. The priming activity was detectable with as little as 1-10 ng LPS per ml blood and was optimal using 1-10 micrograms LPS/ml blood. The priming for 5-LO product synthesis was optimal after 20-30 min of preincubation with LPS and declined at preincubation times > 30 min. The priming effect of LPS was also observed using the complement fragment C5a or interleukin 8 as agonists. Polymorphonuclear leukocytes (PMN) and peripheral blood mononuclear cells accounted for 80 and 20% of the synthesis of 5-LO products, respectively. The ability of LPS to prime isolated PMN was dependent on the presence of plasma and was inhibited by the anti-CD14 antibody IOM2, indicating a CD14-dependent priming mechanism. The priming of whole blood with tumor necrosis factor alpha (TNF-alpha) and LPS was additive and the presence of mononuclear cells did not enhance the ability of LPS to prime PMN, indicating that the priming activity of LPS is independent of LPS-induced TNF-alpha synthesis. The mechanism by which LPS enhance 5-LO product synthesis in PMN was investigated. Treatment of PMN with LPS strongly enhanced the release of arachidonic acid after stimulation with FMLP. The release of arachidonic acid was optimal 2-3 min after stimulation with FMLP, attaining levels 5-15-fold greater than those observed in unprimed cells stimulated with FMLP. These results demonstrate that LPS dramatically increases the ability of blood to generate 5-LO products, and support the putative role of leukotrienes in pathological states involving LPS.

Limited metabolic effect of mononuclear cells in platelet storage

Platelet concentrates (PC) were prepared by platelet apheresis to obtain a low (<0.1 × 10 9/1, PC A) and high (2–9 × 10 9/1, PC B) concentration of white cells from the same donor. The mean platelet count (±SD) of the PC were 1000 ±50 × 10 9/l. During storage 71–96 % of the white cells were mononuclear. A portion of red cells from each donor was also stored under the same conditions. The results of the PC were corrected for the influence of contaminating erythrocytes. During the whole storage period pO 2 was significantly lower in PC with high white cell count, p<0.05 and the concentration of ATP significantly higher, p<0.01 on day 0, 3 and 5, p<0.05 on day 1 and 7. There were no significant differences in pH, pCO 2, production of lactate or consumption of glucose. In another 17 apheresis PC leukocyte viability was assessed by exclusion of 0.05 % trypan blue on days 5 and 7; 90 ± 3 and 88 ± 4 % respectively of the leukocytes remained viable; 87 and 96 % respectively were mononuclear cells. In a third series of PC prepared with extra high white cell count (0.4–1.6 × 10 9/unit) was oxidative phosphorylation maintained and pH remained between 6.80 and 7.16 in 12 of 16 PC after 5 days of storage. The presence of mononuclear cells in PC does not impair the maintenance of platelet ATP production and oxidative phosphorylation unless the platelet concentration is high enough almost to exceed the oxygen diffusion capacity of the bag. If so, the white cells significantly contributed to the oxygen deficit and pH and ATP rapidly decreased due to anaerobic metabolism. We conclude that mononuclear cells can be stored in plasma together with platelets at aerobic conditions for 7 days with maintained concentration of platelet ATP.

An immunohistochemical study of mononuclear cells in meningiomas.

A consecutive series of 34 meningiomas were re-examined as to subtype and presence of nuclear atypia, mitotic figures, areas of high cellularity and necrosis. Meningioma cells were epithelial membrane antigen (EMA) positive in 31 out of the 34 tumours. The presence of mononuclear cells and macrophages was assessed by immunohistochemistry using the monoclonal antibodies L26 (CD20, B cell marker), DF-T1 (CD43, T cell marker), KP1 (CD68, macrophage marker) and MAC387 (monocytes). L26 positive B cells were observed infrequently. CD43 positive mononuclear cells were infiltrating the parenchyma as individual cells and as groups of cells in 29 (87% of the tumours). CD68 positive macrophages were seen in 19 (59% of the tumours), as scattered single cells or groups of cells. There was a statistically significant association between the number of CD68 positive cells (necrotic areas excluded) and microscopic features of aggressiveness, i.e. high cellularity as well as the combination of nuclear atypia and frequent mitotic figures. MAC387 stained only a few cells; the immunopositive cells were present mainly within and around vessels. Meningioma cells displayed a diffuse immunopositivity for L26 (CD20) in 29 out of 34 meningiomas, but did not stain with macrophage markers. Mast cells were found in 9 out of 32 tumours; when present they were significantly more prevalent in the syncytial subtype. Thus, mononuclear cell infiltrates in meningiomas are mainly composed of T cells and macrophages, indicating an immune system surveillance and response to the tumour cells. The functional and prognostic significance of the presence of CD68 positive cells, macrophages, deserve further study in the search for more reliable histological criteria to predict recurrence and biological aggressiveness in meningiomas.

Pathogenesis of Pelvic Inflammatory Disease

Pelvic inflammatory disease is usually caused by Chlamydia trachomatis or Neisseria gonorrhoeae. Chlamydiae and gonococci are primary pathogens of the cervix and often ascend. Resultant damage to the cervix may permit organisms to move upward, but this mechanism of action is not well understood. Puberty and hormones, particularly oral contraceptives, may enhance chlamydial infection, but the mechanisms and likelihood of spread to the upper tract are ill defined. Upper tract infection with C trachomatis involves an acute phase, characterized by an influx of polymorphonuclear leukocytes and a chronic or persistent phase characterized by the presence of mononuclear cells (delayed hypersensitivity). Gonococci invade nonciliated epithelial cells, but are toxic to ciliated cells, due to elaborated lipooligosaccharides and peptidoglycan. Certain gonococci stimulate chemotaxis of polymorphonuclear leukocytes whose release of toxic metabolites may damage tissue. The immunologic mechanisms that permit specific host responses to these two organisms are now being elucidated and should receive more attention by researchers.

The Presence of Intra-lamina Lucida Blister Formation in Epidermolysis Bullosa Acquisita: Possible Role of Leukocytes

In evaluating patients we have noted disparity between the locations of bound immunoreactants and the level of blistering in epidermolysis bullosa acquisita (EBA). We examined 10 consecutive EBA patients by routine histology, direct (DIF) and indirect (IIF; intact and NaCl-split skin) immunofluorescence, immunofluorescence mapping (IM), and/or direct immunoelectron microscopy (DIEM). DIF was positive in each. IIF was positive in 3/8 and 6/7 patients when intact and split skin were used as substrates. DIEM revealed immunoreactants within the lamina densa (LD) in 6/10, sub-LD in 1/10, and both LD and sub-LD in 3/10 patients. In contrast, by DIEM and IM, blister formation was noted within the lamina lucida (LL) in 7/9 and 8/10, sub-LD in 1/9 and 1/10, and within both LL and sub-LD in 1/9 and 1/10, respectively. In the presence of neutrophils within the upper dermis (n = 6), cleavage occurred within the LL in 5 specimens; in one additional specimen containing predominantly neutrophils, cleavage occurred within both LL and sub-LD. In the presence of mononuclear cells (n = 2), intra-LL cleavage occurred. In the presence of eosinophils, cleavage occurred within both LL and sub-LD. In the one specimen lacking any infiltrate, the cleavage plane was exclusively sub-LD. Intra-LL cleavage planes are more common than sub-LD ones in at least early cases of EBA. These findings likely represent the intra-LL-separating effect of leukocyte-derived proteolytic enzymes, when such cells are chemoattracted to the dermoepidermal junction by bound immuno-reactants.

Predictive value of immunofluorescence and electron microscopic evaluation of endomyocardial biopsies in the diagnosis and prognosis of myocarditis and idiopathic dilated cardiomyopathy

The distinction between idiopathic dilated cardiomyopathy and myocarditis is controversia, both clinically and pathologically. To increase diagnostic accuracy and provide prognostic information, we prospectively tested the routine application of immunofluorescence and electron microscopy in endomyocardial biopsy evaluation. Biopsy samples from a consecutive series of 79 patients with cardiomyopathy and possible myocarditis were thus evaluated by light (LM), immunofluorescence (IF), and electron microscopy (EM). Patient course was followed prospectively to determine prognostic factors. Immunoglobulin (IgG) and complement (C) in biopsy tissue were graded 0 to 3+ and an IF score was derived as 2 (IgG) grade + C grade. A highly significant association was found between IF score ≥ 2 and the presence of mononuclear cells (lymphocytes plus macrophages) greater than 5/high-power field, confirmed by EM; 12 of 15 (80%) with IF score ≥ 2 had inflammatory cells, vs only 2 of 64 (3%) with IF score <2 ( p < 0.000001). EM was used to confirm the identity of infiltrating cells and to grade myofilament loss () to 3+) and 11 other ultrastructural features. EM did not provide important predictive information in myocarditis, but confirmed the presence of inflammatory cells. However, the EM finding of myofilament loss provided prognostic information both in patients with and without myocarditis ( p < 0.03). Mortality at 18 months was 37% for patients with 2 to 3+ myofilament loss, vs 10% in those with ) to 1+ loss. Moreover, myofilament loss was prognostically independent of clinical class and ejection fraction. EM determination of myofilament loss is valuable as a prognostic indicator, whether or not myocarditis is present. Rostine IF and EM increase the diagnostic accuracy and prognostic information in endomyocardial biopsies from patients with suspected myocarditis or cardiomyopathy.

Sera from HTLV-III/LAV antibody-positive individuals mediate antibody-dependent cellular cytotoxicity against HTLV-III/LAV-infected T cells.

The causative agent of the acquired immunodeficiency syndrome (AIDS) has been shown to be a human retrovirus called human T lymphotropic virus (HTLV)-III or lymphadenopathy-associated virus (LAV). The nature of the protective immune response against this virus is currently unknown. We report here results using an antibody-dependent cellular cytotoxicity (ADCC) assay which has been developed for measuring a specific immune response against HTLV-III/LAV. Forty-four sera were examined for their ability to mediate ADCC against HTLV-III/LAV-infected T cells. Sera from healthy HTLV-III/LAV seropositive individuals in the presence of mononuclear cells from healthy HTLV-III/LAV seronegative donors exhibited significantly higher levels of ADCC activity compared to sera from patients with AIDS. Western blot analysis of serum samples indicated that antibody reactivity with the p24 protein of HTLV-III/LAV correlated with higher levels of ADCC activity than did reactivity with Gp120/160. The observation that sera from healthy HTLV-III/LAV seropositive individuals mediated higher levels of ADCC activity than did sera obtained from subjects with AIDS suggests that ADCC may represent a protective immune response to infection with HTLV-III/LAV.

Ultrastructural observations in lichen nitidus.

Lichen nitidus (LN) and lichen planus (LP) are considered by some investigators to be two variants of the same disease, and by others to be two distinct dermatoses. In order to obtain further information about the relationship between LN and LP we examined the ultrastructure of lesions from two LN patients. In the central part of the lesion, the basement membrane was absent, or was interrupted by migrating phagocytes or lymphocytes. The basal cells and the lower cells of the stratum spinosum exhibited karyolysis and appeared to be compressed and often necrotic. In the upper dermis irregular cell debris full of clumps of tonofilaments and colloid-body-like structures was observed. A dense dermal infiltrate of macrophages, lymphocytes, fibrocytes, and Sezary-like cells was present. Signs of cooperation between lymphocytes and macrophages were also evident. The periphery of the lesion showed no pathological features except for enlargement of the intercellular spaces and the presence of mononuclear cells scattered through the epidermis. Several normal Langerhans cells were noticed. These ultrastructural findings were quite similar to those reported for LP.

Stimulation of procollagenase synthesis in human rheumatoid synovial fibroblasts by mononuclear cell factor/interleukin 1

In order to define mechanisms regulating the synthesis of procollagenase in human rheumatoid synovial fibroblasts, the proteins synthesized by cultured cells were labeled with [ 35S]methionine. Labeled medium proteins were analyzed by SDS-PAGE directly and after immunocomplexing with a specific antibody to human fibroblast collagenase. Labeling of both the predominant form of the enzyme ( M r~55000) as well as a minor species ( M r~61000) was increased following incubation with the monokine, mononuclear cell factor/interleukin 1. The ~61 kDa form of the procollagenase appears to be a glycosylated form of the ~ 55 kDa precursor based on binding to Con A-Sepharose and decrease in the $ ̃ 61 kDa form after culture in the presence of tunicamycin. Thus, mononuclear cell factor, homologous with interleukin 1, partially purified from monocyte conditioned medium increass incorporation of [ 35Simethionine into several medium proteins, including those complexed by the anticollagenase antibody. In the presence of mononuclear cell factor/interleukin 1, labeling of the procollagenase was increased 12-14-fold over control cultures incubated with medium alone. Therefore, one of the mechanisms involved in increase of collagenase activity in the medium of cultured synovial fibroblasts in the presence of mononuclear cell factor/interleukin 1 is a stimulation of enzyme protein synthesis.

The effects of flurbiprofen and indomethacin on the mitogenic response of human peripheral mononuclear cells

The effects of flurbiprofen (FBP) and indomethacin (INDO) on the incorporation of [3H]thymidine into human peripheral mononuclear cells after stimulation with phytohaemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM) were investigated. FBP and INDO enhanced [3H]thymidine incorporation only at suboptimal concentrations of PHA and Con A but the concentration of PWM was less critical.Enhancement depended upon the presence of mononuclear cells which could be removed by adherence to plastic: these may be tentatively identified as monocytes (macrophages). INDO enhanced [3H]thymidine uptake to a greater degree than FBP and its effect was decreased to a greater extent by removal of monocytes.The enhancing effects of INDO and FBP are completely reversible by thorough washing of cells which had been exposed to the drugs and could be regained by direct addition of drugs to previously washed cells. Concurrent addition of both drugs to cell cultures showed neither antagonism nor synergy with respect to the effect of one drug alone. PGE2 inhibited [3H]thymidine incorporation. Like that of FBP and INDO, this action was dependent on mitogenic dose and apparent at suboptimal doses only. A low concentration of exogenous PGE2 (2 ng/ml) was sufficient to prevent the enhancing effect of both FBP and INDO.

Metabolic and cellular alterations underlying the exaggerated renal prostaglandin and thromboxane synthesis in ureter obstruction in rabbits. Inflammatory response involving fibroblasts and mononuclear cells.

Unilateral ureter obstruction in rabbits produced profound changes in endogenous and exogenous renal arachidonic acid metabolism. Isolated perfused hydronephrotic kidneys (removed after 3 or 10 d of ureter obstruction) responded to bradykinin stimulation with a markedly enhanced release of prostaglandin E2 and thromboxane A2. Reversal (3 or 10 d) of the ureter obstruction resulted in a reduction in the vasoactive peptide-induced release of prostaglandin E2 and thromboxane A2 from the perfused hydronephrotic kidney. However, postobstruction reversal of prostaglandin production by the agonist-stimulated perfused kidney was not reflected in the cortical microsomal cyclooxygenase activity, which is greatly enhanced during ureter obstruction and does not decrease after removal of the obstruction. Histological analysis of the renal cortex in rabbits with ureteral obstruction revealed a proliferation of fibroblast-like cells and the presence of mononuclear cells; removal of the obstruction did not result in a disappearance of cortical fibroblasts but did result in a decrease of monocytes. The critical involvement of mononuclear cells in the exaggerated arachidonate metabolism that occurs during hydronephrosis was exhibited by the demonstration that: (a) only the perfused hydronephrotic rabbit kidney responded to administration of endotoxin with a sustained release of prostaglandin E2 and thromboxane A2; (b) the contralateral rabbit kidney, which is devoid of mononuclear cells, did not respond to endotoxin; and (c) the hydronephrotic cat kidney, which exhibits a fibroblast proliferation with a low number of mononuclear cells, did not respond to endotoxin. Thus, proliferation of fibroblast-like cells and the presence of mononuclear cells appear to be involved in the exaggerated prostaglandin and thromboxane production underlying hydronephrosis. The increase in microsomal cyclooxygenase activity is apparently most closely correlated with the increased fibroblastic activation and cellularity, whereas mononuclear cells (possibly via monokines) seem to be critical for the markedly enhanced prostaglandin and thromboxane release induced by endotoxin and bradykinin.

Granuloma annulare

Granuloma annular (GA) is a benign inflammatory skin disease usually localized to the distal extremities, although generalized, perforating, and subcutaneous variants have also been identified. A regular histopathologic feature is the presence of mononuclear cells, often in palisading array, around foci of altered collagen. The clinical and histologic features of each subtype of GA are discussed along with a differential diagnosis. A variety of remedies have been used to treat GA, but efficacy is hard to define in a disease in which spontaneous resolution is usual outcome. GA has not been conclusively linked either to diabetes or solar radiation. Recent data suggest a role for vascular injury or delayed-type hypersensitivity in the pathogenesis, but the cause of GA remains obscure.

Effect of peripheral blood mononuclear cells from aplastic anemia patients on the granulocyte-macrophage and erythroid colony formation in samples from normal human bone marrow in vitro--a cooperative work

Thirty-six patients with aplastic anemia and three with aplastic anemia- PNH syndrome in eight institutes were studied for the presence of peripheral blood mononuclear cells having a suppressive effect on granulocyte-macrophage (G-M) and erythroid colony formation using a uniform protocol. In 11 cases of 29 (38%) and 9 cases of 29 (31%), the presence of mononuclear cells with a suppressive effect on G-M and erythroid colony formation, respectively, was demonstrated. However, the presence of mononuclear cells suppressive both to G-M and erythroid colony formation was demonstrated only in 3 of 19 cases (16%).

Characterization of Cells of the Normal Aortic Endothelium of Adult Rats and Changes due to Endotoxin Shock: I. Communication: Light Microscopy, Autoradiography, DNA Cytophotometry, and Enzyme Histochemistry

Aortic endothelium of normal and endotoxin treated rats was investigated in "Häutchen" preparations by light microscopy, autoradiography, DNA cytophotometry, and enzyme histochemistry. In the endothelium of control rats the following cell populations were found: 1. Endothelial cells (90% of all cells in endothelium), characterized by the alignment of the longitudinal axis of their nuclei, their light microscopic morphology, their DNA content resp. DNA synthesis, and by their enzymatic activity; 2. mononuclear cells (10% of all cells in endothelium), identified as mature blood monocytes, mononuclear phagocytes (macrophages), and as lymphocytes; 3. granulocytes (less than 1% of all cells in endothelium). The presence of mononuclear cells and granulocytes in the normal endothelium appears to be the expression of a physiological repair process in endothelium. After endotoxin application one can observe an endothelial damage and then a repair process. During the repair of endothelium the following processes occurred: An increase of DNA synthesis particularly of endothelial cells, an aggregation of platelets on the endothelial surface, an increase in number of granulocytes and at last an increase in number of activated mononuclear cells. Participation of mononuclear cells in the physiological as well as in the pathological repair process of endothelium was shown by the present investigation. The process of transformation of mononuclear cells into endothelial cells is discussed at the same time.

ELECTRON MICROSCOPIC STUDIES ON THE VASCULAR PERMEABILITY AND THE MECHANISM OF DEMYELINATION IN EXPERIMENTAL ALLERGIC ENCEPHALOMYELITIS.

Abstract : In early lesions of experimental allergic encephalomyelitis in rats Thorotrast passes through vessel walls concomitant with invading mononuclear cells. The particles are found between the endothelial cells, within the vacuolated basement membrane, and in the extracellular space between glial processes. In advanced lesions, markedly widened extracellular spaces often contain threads of fibrin along with Thorotrast. Demyelination occurs in the presence of mononuclear cells which invade the myelin sheath, peeling off individual myelin lamellae or the entire sheath. A separate alteration of myelin consists of a regular widening of the interlamellar space beginning with the outer layers. The possibility that this change precedes the cellular invasion of the myelin sheath is discussed. (Author)

A Rickettsia-like Organism Recovered from Guinea Pigs.

Summary and ConclusionsAn agent pathogenic for guinea pigs has been isolated. The organisms appeared as small pleomorphic bacillary forms, staining red by the Machiavello method and gram negative. They were larger than the known rickettsia, as well as P. tularensis and Brucella, and were immunologically distinct from them. They grew fairly well in the yolk sac of the fertile hen's egg but were not cultivated on artificial media. The host range was limited to the guinea pig except when enormous doses were given.After a short incubation period, peritonitis was produced in the guinea pig, for which the agent was highly virulent, and a specific immunity resulted in recovered animals. The inflammatory reaction in the tissues was characterized chiefly by the presence of mononuclear cells. The organism appeared predominantly intracytoplasmic in impression smears of the spleen.The origin of the organism is in doubt. It has not been possible to identify it with any known group of pathogenic agents, but at present ...

Regeneration of Virus Myxomatosum (Sanarelli) in the Presence of Cells of Exudates Surviving in Vitro.

For a number of years the relation of viruses to cells has been under investigation in our laboratory. In pursuance of this study, attempts to cultivate the virus of infectious myxomatosis of rabbits in different kinds of tissue cultures were made. At the beginning of the work, bits of rabbit testicle suspended in a mixture of rabbit serum (1 part) and Tyrode's solution (3 parts) were used as a medium. Such preparations, however, proved unsuitable for the in vitro cultivation of the virus. Previous observations indicated that large mononuclear wandering cells are involved in this disease. Therefore, it seemed not unlikely that the inadequacy of the above methods of cultivation was referable to the failure of mobilization of these cells in excised tissues. To test this hypothesis, attempts to cultivate the virus in the presence of mononuclear cells obtained according to the method of Gay and Clark1 were made.A sterile mixture (6 cc.) of beef extract and gum acacia was injected into the right pleural cavity...