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PubMed1994

Distinction of class II MHC+ Langerhans cell-like interstitial dendritic antigen-presenting cells in murine dermis from dermal macrophages.

Dermal cells are capable of initiating contact-hypersensitivity responses but the precise identification of the antigen-presenting cell within murine dermis is lacking. Class II major histocompatibility complex (MHC)+ cells with dendritic shape and lacking endothelial factor VIII but expressing the dendritic antigen-presenting cell marker NLDC-145 were observed in the perivascular and interstitial dermis of BALB/c and C3H/HeN skin. The heterogeneous class II MHC+ cells could be divided into two subsets: each was class II MHC+ CD45+ (bone marrow derived) GR-1- (non-neutrophil/macrophage) CD3- (non T), but one subset was CD11b+ (beta 2 integrin) and the other was CD11b-. Ultrastructural examination of class II MHC+ cells revealed the presence of a Langerhans cell-like/indeterminant cell subset with indented nuclei, dendritic morphology, active cytoplasm, and dense intermediate filaments. Phagolysomes and Birbeck granules were not observed in such cells, indicating these were distinct from dermal macrophages and from classical epidermal Langerhans cells, respectively. Cells with a monocyte/macrophage ultrastructural appearance were also noted, likely representing the class II MHC subset expressing CD11b and Ly6c (monocyte/endothelial antigen). Dermal cells in suspension were capable of processing and presenting large protein antigens to antigen-specific T-cell hybridomas; dermal cells also induced the syngeneic mixed lymphocyte reaction. The dermal antigen-presentation activities were totally abrogated by removal of class II MHC+ cells, but not by removal of CD11b+ cells or Ly6c+ cells, indicating that potent antigen-presenting cell activity was restricted to the class II MHC+ CD11b- Ly6c- subset (Langerhans cell-like/indeterminant cells). In conclusion, within a complex array of dermal leukocytes a murine dermal class II MHC+ cell population expressing a Langerhans cell-like/dendritic antigen-presenting cell phenotype and exhibiting potent antigen processing and presenting activity can be identified. The positioning of potent interstitial dendritic antigen-presenting cells at the interface of the vasculature with the dermal interstitium provides rapid access to an antigen-presenting cell as T cells first egress into the skin.

Animals↗

PubMed1996

Functional importance of the dihydropyridine-sensitive, yet voltage-insensitive store-operated Ca2+ influx of U937 cells.

The Ca2+ current activated by Ca2+ store depletion in non-excitable cells is classically regarded as being dihydropyridine-insensitive, suggesting that store-operated Ca2+ channels (SOCs) are dissimilar to voltage-gated Ca2+ channels (VGCs) of excitable-cells. Here, we demonstrate dihydropyridine-sensitivity for the store-operated Ca2+ influx induced by ATP and thapsigargin (Tg) in the non-excitable U937 cell-line. Ca2+ store depletion by prior treatment of cells with either Tg or ATP, stimulated a Ca2+ entry mechanism that was inhibited by nicardipine, nifedipine, and the specific L-type Ca2+ channel blocker, calciseptine. A functional requirement for this Ca2+ influx mechanism in agonist-induced mitogenesis seemed likely, since nicardipine, a particularly potent inhibitor of store-operated Ca2+ influx in these cells, suppressed ATP- and Tg-stimulated cell proliferation. Depolarisation of cells with KCl, or gramicidin failed to elicit an increase in cytosolic Ca2+, suggesting that while the store-operated Ca2+ influx channel of U937 cells shares pharmacologic properties with the L-type Ca2+ channel, it is voltage-insensitive and therefore may resemble an L-type Ca2+ channel lacking a voltage sensor.

Adenosine Triphosphate↗

PubMed2001

Effect of emedastine difumarate on CC chemokine-elicited eosinophil migration.

Emedastine difumarate (emedastine) is an antiallergic drug found among the derivatives which has a series of benzimidazole frames. It has been reported that emedastine can significantly inhibit the migration of eosinophils elicited by classical chemoattractants, including LTB4 or PAF. However, the effect of emedastine on the selective migration of eosinophils that have been stimulated with CC chemokines has not been examined. Emedastine at concentrations of 10 nM or higher strongly inhibited the eosinophil migration elicited by CC chemokines, including eotaxin, RANTES and MCP-3. Preincubation of the eosinophils with emedastine did not alter the expression of the CCR3 receptor, although a decrease in the concentration of intracellular calcium ions was observed after stimulation with 100 ng/ml of eotaxin. Herbimycin A, genistein, staurosporin and emedastine were all able to inhibit the eotaxin-elicited migration. Tyrosine kinase activity in the cytosol supernatant of eosinophils obtained after stimulation with eotaxin significantly decreased when the eosinophils were preincubated with emedastine. In addition, protein kinase A and protein kinase C activities in eotaxin-stimulated EoL-1 cell supernatants decreased significantly with emedastine pretreatment. These findings suggest that emedastine inhibits CC chemokine-elicited eosinophil migration by decreasing the activities of tyrosine kinase or protein kinases but does not alter CCR3 expression.

Anti-Allergic Agents↗

PubMed2004

The chemoattractants, IL-8 and formyl-methionyl-leucyl-phenylalanine, regulate granulocyte colony-stimulating factor signaling by inducing suppressor of cytokine signaling-1 expression.

Suppressors of cytokine signaling (SOCS) are encoded by immediate early genes known to inhibit cytokine responses in a classical feedback loop. SOCS gene expression has been shown to be induced by many cytokines, growth factors, and innate immune stimuli, such as LPS. In this paper, we report that the chemoattractants, IL-8 and fMLP, up-regulate SOCS1 mRNA in human myeloid cells, primary human neutrophils, PBMCs, and dendritic cells. fMLP rapidly up-regulates SOCS1, whereas the induction of SOCS1 upon IL-8 treatment is delayed. IL-8 and fMLP did not signal via Jak/STATs in primary human macrophages, thus implicating the induction of SOCS by other intracellular pathways. As chemoattractant-induced SOCS1 expression in neutrophils may play an important role in regulating the subsequent response to growth promoting cytokines like G-CSF, we investigated the effect of chemoattractant-induced SOCS1 on cytokine signal transduction. We show that pretreatment of primary human neutrophils with fMLP or IL-8 blocks G-CSF-mediated STAT3 activation. This study provides evidence for cross-talk between chemoattractant and cytokine signal transduction pathways involving SOCS proteins, suggesting that these chemotactic factors may desensitize neutrophils to G-CSF via rapid induction of SOCS1 expression.

Carrier Proteins↗

PubMed2005

Constitutive intracellular expression of human leukocyte antigen (HLA)-DO and HLA-DR but not HLA-DM in trophoblast cells.

The nonclassic human leukocyte antigen (HLA)-DM molecules have been proved to positively regulate antigen presentation in classic antigen-presenting cells, whereas in B lymphocytes HLA-DO have been identified as negative regulators of the process. The present report examines whether the negative expression of classic class II molecules in trophoblasts implies negative regulation by HLA-DO. It was revealed by immunofluorescence, confocal microscopy, and subcellular fractionation techniques that human trophoblasts, although not expressing any surface HLA-DR antigens, constitutively express intracellular HLA-DR, HLA-DO, and CD74, but not HLA-DM. Administration of interferon-gamma to the cell culture increased HLA-DR and CD74, induced HLA-DM, but did not alter the expression of HLA-DO and induced HLA-DR release from the cells. These results were confirmed by reverse transcriptase-polymerase chain reaction analysis except that HLA-DM mRNA was detected in control cells, indicating a posttranscriptional regulation. Under the same experimental conditions, human monocytes/macrophages were not expressing intracellular HLA-DO while exhibiting significant levels of HLA-DR, HLA-DM, and CD74. The results presented here reveal for the first time expression of HLA-DO in trophoblasts, which can be of great importance in maintaining the class II-negative state in these cells and consequently protecting the fetus from maternal immune attack.

Animals↗

PubMed1983

Suppression of in vitro lymphocyte DNA synthesis by killed Pseudomonas aeruginosa.

Whole antibiotic-killed classic Pseudomonas aeruginosa organisms elicited human lymphocyte [3H]thymidine (TdR) uptake in vitro after 5 days in culture. However, high concentrations of the same preparation did not elicit [3H]TdR incorporation. The investigation of this lymphocyte unresponsiveness revealed that a high dose of P. aeruginosa, when added to lymphocyte cultures together with optimal concentrations of lymphocyte activators (e.g., plant lectins or whole killed Staphylococcus aureus Cowan 1), caused a potent, nonspecifically expressed inhibition of lymphocyte [3H]TdR uptake in response to these mitogens. High doses of P. aeruginosa were not cytotoxic to lymphocytes, and the inhibition caused was reversed when lymphocytes were washed free of bacteria. The inhibition of [3H]TdR uptake by high-dose P. aeruginosa did not require the generation of adherent suppressor cells or prostaglandin-mediated, steroid-sensitive or radiation-sensitive suppressor mechanisms. At optimal lymphocyte stimulatory concentrations of P. aeruginosa, the addition of indomethacin or the depletion of adherent cells caused an increase in lymphocyte [3H]TdR incorporation. This is consistent with an adherent-cell population regulating [3H]TdR uptake in response to P. aeruginosa via a prostaglandin-dependent pathway. This population was not involved in the inhibition of lymphocyte [3H]TdR uptake by high concentrations of P. aeruginosa.

Cell Survival↗

PubMed2003

Unique appearance of proliferating antigen-presenting cells expressing DC-SIGN (CD209) in the decidua of early human pregnancy.

Intact human pregnancy can be regarded as an immunological paradox in that the maternal immune system accepts the allogeneic embryo without general immunosuppression. Because dendritic cell (DC) subsets could be involved in peripheral tolerance, the uterine mucosa (decidua) was investigated for DC populations. Here we describe the detailed immunohistochemical and functional characterization of HLA-DR-positive antigen-presenting cells (APCs) in early pregnancy decidua. In contrast to classical macrophages and CD83(+) DCs, which were found in comparable numbers in decidua and nonpregnant endometrium, only decidua harbored a significant population of HLA-DR(+)/DC-SIGN(+) APCs further phenotyped as CD14(+)/CD4(+)/CD68(+/-)/CD83(-)/CD25(-). These cells exhibited a remarkable proliferation rate (9.2 to 9.8% of all CD209(+) cells) by double staining with Ki67 and proliferating cell nuclear antigen. Unique within the DC-family, the majority of DC-SIGN(+) decidual APCs were observed in situ to have intimate contact with CD56(+)/CD16(-)/ICAM-3(+) decidual natural killer cells, another pregnancy-restricted cell population. In vitro, freshly isolated CD14(+)/DC-SIGN(+) decidual cells efficiently took up antigen, but could not stimulate naive allogeneic T cells at all. Treatment with an inflammatory cytokine cocktail resulted in down-regulation of antigen uptake capacity and evolving capacity to effectively stimulate resting T cells. Fluorescence-activated cell sorting analysis confirmed the maturation of CD14(+)/DC-SIGN(+) decidual cells into CD25(+)/CD83(+) mature DCs. In summary, this is the first identification of a uterine immature DC population expressing DC-SIGN, that appears only in pregnancy-associated tissue, has a high proliferation rate, and a conspicuous association with a natural killer subset.

Abortion, Therapeutic↗

PubMed2003

Tissular insemination of progenitor endothelial cells: the problem, and a suggested solution.

The contribution of circulating precursor endothelial cells (CPEC) to adult angiogenesis is now well established. However, the mechanism of their tissular engrafting remains poorly understood. The classical paradigm of "sprouting" cannot accommodate the main features of the CPEC-based angiogenic process. Additionally, vasculogenesis based on the differentiation of angioblasts, as defined in the embryonic stages, is not applicable to adult neo-vascularization either. In search for a solution to this dilemma, I suggest that the ability of monocytes/macrophages to produce tunnels, as effect of their protease-dependent migration in the extracellular matrices, is instrumental for the tissular insemination of CPEC. Here I present in vivo and in vitro experimental evidence for the existence of tunnels, and for their colonization by monocytes/macrophages and by other cells, including CPEC. As a paradigm of CPEC behavior, the tunneling model (in an extended sense) may also explain the propagation of the endothelium with arteriolar phenotype within the pre-existent downstream capillary network. Thus, the sprouting mechanism might be a valid explanation for the formation of new capillaries and venules, whereas CPEC would contribute mostly, if not exclusively, to the extension of arteriolar branches of microvasculature. Adult angiogenesis occurs therefore as a multifunctional process based on intercellular cooperation, in which there are involved endothelial cells (EC) or their precursors, as well as other cell types. In specific circumstances, the lumen (i.e. the tunnel) may occur before the "definitive" microvessel. Therefore the very notion of microvessel may need to be extended, to include the tunnels.

Animals↗

PubMed1996

S100 protein CP-10 stimulates myeloid cell chemotaxis without activation.

Leukocyte recruitment to inflammatory foci is generally associated with cellular activation. Recent evidence suggests that chemotactic agents can be divided into two classes, "classical chemoattractants" such as FMLP, C5a, and IL-8, which stimulate directed migration and activation events and "pure chemoattractants" such as TGF-beta 1 which influence actin polymerisation and movement but not oxidative burst and associated granular enzyme release. The studies reported here demonstrate that the murine S100 chemoattractant protein, CP-10, belongs to the "non-classical" group. Despite its potent chemotactic activity for neutrophils and monocytes/macrophages, CP-10 failed to increase [Ca2+]i in human or mouse PMN, although chemotaxis was inhibited by pertussis toxin, confirming the suggestion of a novel Ca(2+)-independent G-protein-coupled pathway for post-receptor signal transduction triggered by "pure chemoattractants." The co-ordinated up-regulation of Mac-1 and down-regulation of L-selectin induced by FMLP on human PMN in vitro was not observed with CP-10. Quantitative changes in immediate (30 s) actin polymerisation occurred with FMLP and CP-10-treated human PMN. The relative F-actin increases induced in WEHI 265 monocytoid cells by FMLP and CP-10 was optimal at 60 s and declined over 120 s. F-actin changes reflected the concentration and potencies of the agonists required to provoke chemotaxis. After 90 min, CP-10 profoundly altered cell shape and increased both cell size and F-actin within pseudopodia. These changes are typical of those mediating leukocyte deformability, and CP-10 may mediate leukocyte retention within microcapillaries and thereby contribute to the initiation of inflammation in vascular beds.

Actins↗

PubMedDate not supplied

WP744, a novel anthracycline with enhanced proapoptotic and antileukemic activity.

BACKGROUND: MDR1 or MRP1 drug resistance mechanisms seriously limit the efficacy of anthracyclines such as doxorubicin, in the treatment of acute myeloid leukemia (AML). Our studies indicated that reducing basicity, increasing steric hindrance at C-4', and/or lipophilicity may help circumvent P-glycoprotein (P-gp)-mediated anthracycline efflux and thus increase drug retention in MDR-positive cells. From a series of 4'-substituted analogs, 4'-O-benzylated doxorubicin (WP744) was selected for a comparison with the classic anthracycline doxorubicin for their cytotoxic and pro-apoptotic properties. WP744 retains cytotoxic activity against P-gp and MRP-positive cells. METHODS AND RESULTS: In three AML cell lines (K562, KBM-3, and OCIM2) WP744 was markedly more potent (IC50 values of 0.18, <0.05, and <0.05 microg/ml, respectively) than doxorubicin (IC50 values of >0.5, 0.07, and 0.09 microg/ml, respectively). Likewise, WP744 inhibited the colony formation by AML-CFU cells from fresh bone marrow of three AML patients more strongly than doxorubicin. Cell growth inhibition by WP744 is accompanied by apoptosis induction as shown by TUNEL assay in OCIM2 cells. WP744-induced apoptosis appears to be mediated by caspase-3 as apoptotic changes were abrogated in the presence of the caspase 3 inhibitor Z-DEVD-FMK. Accordingly, caspase 3 activity was elevated in the lysates from drug-treated cells. WP744 induced also cleavage of apoptotic marker poly(ADP-ribose)polymerase (PARP). Finally, WP744 at 0.05 microM and greater was a potent inducer of apoptosis (by quantitative DNA fragmentation) in cultured human acute lymphoblastic leukemia (ALL) CEM cells, compared to 0.5 microM doxorubicin needed for a similar effect. CONCLUSION: The novel anthracycline WP744 was found to be an antileukemic agent with proapoptotic activity superior to that of doxorubicin.

Adult↗

PubMed1994

Human serum amyloid A genes are expressed in monocyte/macrophage cell lines.

Serum amyloid A (apoSAA) is a family of proteins found, mainly associated with high density lipoproteins, in the blood plasma of mammals and at least one avian species, the Pekin duck. These proteins are present in small amounts under normal circumstances, but their concentration is capable of rising 100- to 1,000-fold in situations involving tissue injury or infection. Like classic acute phase proteins they are produced in the liver; however, expression of one of the apoSAA genes is known to occur in activated macrophages of mice. We examined three human macrophage precursor cell lines (THP-1, U-937, and HL-60), before and after differentiation with phorbol 12-myristate 13-acetate or 1 alpha,25-dihydroxy-vitamin D3, for apoSAA messenger (m)-RNA expression and found that: 1) induction of steady-state apoSAA mRNA by lipopolysaccharide, interleukin-1, or interleukin-6 required the presence of the synthetic glucocorticoid dexamethasone; 2) the three known active genes, apoSAA1, apoSAA2, and apoSAA4, were induced in THP-1 cells, whereas the pseudogene apoSAA3 was not; 3) differentiated and undifferentiated THP-1 cells expressed apoSAA mRNA, but U-937 cells expressed apoSAA mRNA (low levels) only after phorbol 12-myristate 13-acetate differentiation and HL-60 cells did not express apoSAA mRNA whether differentiated or not; 4) apoSAA protein was detectable immunologically at a low level in lyophilized medium from induced THP-1 cells. Our findings are compatible with the hypotheses that 1) apoSAA gene expression in human monocytes/macrophages in vivo is differentiation dependent; 2) activated macrophages provide a local source of apoSAA at sites of tissue injury or inflammation; 3) apoSAA is induced in tissue macrophages by local stimuli, under conditions that may not evoke the systemic acute phase response.

Base Sequence↗

PubMed1983

Synthesis of complement by macrophages and modulation of their functions through complement activation.

During the last decade considerable progress has been made to characterize intimate functional links between macrophages, a major cellular component of immunoinflammatory responses, and the complement system representing the major humoral mediator of inflammation. Macrophages of various species and tissue sites have been shown to synthesize and release most of the complement components providing these cells with their own "pericellular" complement system. Circumstantial evidence for the assembly of both classical and alternative pathway convertases has been adduced. An intricate network of feedback loops involving endogenous and extrinsic factors operates to adjust complement production to acute requirements, for example augmenting production in the face of accelerated turnover at sites of inflammation, and returning it to baseline levels once the inflammatory stimulus has subsided, in order to maintain a fine-tuned balance. The molecular mechanisms underlying regulation of complement synthesis by macrophages are beginning to be elucidated by use of gene technology. On the other hand, complement activation products exert a number of effects on macrophages via specific surface receptors causing internalization of offending agents, microbes, and immune complexes, promotion of intracellular killing, controlling migration behavior, inducing release of potent biologic substances such as lysosomal enzymes, arachidonic acid metabolites, and interleukin 1. In these interactions, two important humoral mediator systems of inflammation, the complement system and the arachidonic acid cascade, are functionally linked at the level of the macrophage. Stimulation of the release of immunomodulating compounds from macrophages invoke a role for complement in immune regulation. This multifaceted interplay is of particular importance considering the mobility of macrophages that allows them to gain almost unrestricted access to sites of ongoing immunoinflammatory responses. The time seems to have come to abandon the petrified thinking in socalled systems as, for instance, humoral versus cellular, specific versus unspecific, and to proceed to interlocking functions guided by physiology proper.

Anaphylatoxins↗

PubMed2003

Quantitative detection of hepadnavirus-infected lymphoid cells by in situ PCR combined with flow cytometry: implications for the study of occult virus persistence.

The detection of small amounts of viral pathogens in infected cells by classical PCR is hampered by a partial loss of virus nucleic acid due to extraction and by difficulties in discrimination between truly intracellular virus genome material and that possibly adhered to the cell surface. These impediments limit reliable identification of virus traces within infected cells, which are typically encountered in latent and persistent occult infections. In this study, hepadnavirus-specific in situ PCR combined with the enzymatic elimination of extracellular virus and flow cytometry permitted detection of viral genomes in lymphoid cells without nucleic acid isolation and allowed quantification of infected cells during the course of persistent infection with woodchuck hepatitis virus (WHV). The validity of the procedure was confirmed by hybridization analysis of the in situ-amplified viral sequences. The results showed that hepadnavirus can be directly detected within lymphoid cells not only in serologically accountable infection, but also years after recovery from viral hepatitis and in the course of primary occult virus carriage. Percentages of infected peripheral lymphoid cells in symptomatic WHV hepatitis fluctuate between 3.4 and 20.4% (mean +/- standard error of the mean, 9.6% +/- 1.7%), whereas those in persistent, serologically mute WHV infection range from 1.1 to 14.6% (mean +/- standard error of the mean, 4.8% +/- 0.8%) (P = 0.005). The data obtained provide further evidence that WHV infection continues indefinitely in the lymphatic system independently of whether it is symptomatic or concealed. They document that hepadnavirus can be detected in a significant proportion of circulating lymphoid cells in both immunovirologically apparent as well as occult persistent infection.

Animals↗

PubMed2004

The C4b-binding protein-protein S complex inhibits the phagocytosis of apoptotic cells.

The phagocytosis of apoptotic cells is a complex process involving numerous interactions between the target cell and the macrophage. We have examined a role of the major soluble inhibitor of the classic and lectin complement pathways, C4b-binding protein (C4BP), in the clearance of apoptotic cells. The major form of C4BP present in blood is composed of seven alpha-chains and one beta-chain, which binds protein S (PS). Approximately 70% of all PS in human plasma is trapped in such a complex and is able to localize C4BP to the surface of apoptotic cells due to the high affinity to phosphatidylserine. Free PS has recently been shown to enhance phagocytosis of apoptotic cells by macrophages. We observed a stimulatory effect of free PS on the engulfment of apoptotic cells (BL-41 and Jurkat) by primary human macrophages or THP-1 cells and a decrease of activity in serum depleted of PS in agreement with previous results. However, we also show that the process is strongly inhibited in the presence of the C4BP-PS complex. Addition of the C4BP-PS complex to serum deficient in both molecules abolished the enhancing effect of serum on phagocytosis. The effect of both free PS and the C4BP-PS complex could be inhibited with monoclonal antibody directed against the Gla domain of PS. Although the presence of the C4BP-PS complex on apoptotic cells may lead to decreased phagocytosis, it may still be beneficial to the host, since it could prevent secondary necrosis because it inhibits further complement attack.

Antibodies, Monoclonal↗

PubMed1998

Measurement of Candida-specific blastogenesis: comparison of carboxyfluorescein succinimidyl ester labelling of T cells, thymidine incorporation, and CD69 expression.

Measurement of the T cell blastogenic response to Candida may be useful in the evaluation of patients with suspected immunodeficiency. The classic blastogenesis assay is based on uptake of [3H]thymidine by peripheral blood lymphocytes stimulated with Candida antigens for 5 days. An alternative approach involves staining peripheral blood lymphocytes with the intracellular fluorescent dye carboxyfluorescein succinimidyl ester (CFSE) and measuring mitotic activity by the successive twofold reductions in fluorescent intensity using flow cytometry (FCM). The two approaches were compared in 16 subjects who demonstrated various proliferative responses to Candida. FCM-derived indices all involved initial gating on CD3+ T cells and included 1) blastic transformation as measured by changes in light scatter, 2) cell division, measured by CFSE fluorescence, and 3) CD69 expression. A good correlation was found between [3H]thymidine uptake and CFSE-derived indices, irrespective of the analysis algorithm used to interpret CFSE division profiles. Furthermore, significant T cell proliferation occurred only in subjects who had had one or more symptomatic episodes of vaginal candidiasis whereas controls with no such history, and patients with chronic vaginal infection, showed minimal proliferation. The increase in proportion of CD69+ T cells in culture also correlated with the blastogenic response to Candida, but less well than mitotic indices. CFSE-derived indices of T cell blastogenesis to Candida are equivalent to [3H]thymidine-based assays and may allow useful laboratory distinction between subjects who have been exposed to and recovered from vaginal Candida infection, who have a strong proliferative response, from those with no exposure or chronic infection who demonstrate a poor response.

Antigens, CD↗

PubMed2006

Identifying illness parameters in fatiguing syndromes using classical projection methods.

OBJECTIVES: To examine the potential of multivariate projection methods in identifying common patterns of change in clinical and gene expression data that capture the illness state of subjects with unexplained fatigue and nonfatigued control participants. METHODS: Data for 111 female subjects was examined. A total of 59 indicators, including multidimensional fatigue inventory (MFI), medical outcome Short Form 36 (SF-36), Centers for Disease Control and Prevention (CDC) symptom inventory and cognitive response described illness. Partial least squares (PLS) was used to construct two feature spaces: one describing the symptom space from gene expression in peripheral blood mononuclear cells (PBMC) and one based on 117 clinical variables. Multiplicative scatter correction followed by quantile normalization was applied for trend removal and range adjustment of microarray data. Microarray quality was assessed using mean Pearson correlation between samples. Benjamini-Hochberg multiple testing criteria served to identify significantly expressed probes. RESULTS: A single common trend in 59 symptom constructs isolates of nonfatigued subjects from the overall group. This segregation is supported by two co-regulation patterns representing 10% of the overall microarray variation. Of the 39 principal contributors, the 17 probes annotated related to basic cellular processes involved in cell signaling, ion transport and immune system function. The single most influential gene was sestrin 1 (SESN1), supporting recent evidence of oxidative stress involvement in chronic fatigue syndrome (CFS). Dominant variables in the clinical feature space described heart rate variability (HRV) during sleep. Potassium and free thyroxine (T4) also figure prominently. CONCLUSION: Combining multiple symptom, gene or clinical variables into composite features provides better discrimination of the illness state than even the most influential variable used alone. Although the exact mechanism is unclear, results suggest a common link between oxidative stress, immune system dysfunction and potassium imbalance in CFS patients leading to impaired sympatho-vagal balance strongly reflected in abnormal HRV.

Adult↗

PubMed1985

Complement effector mechanisms in health and disease.

Complement is an effector system able to mediate a number of biological activities in vitro and in vivo. Most familiar is the ability of the system to mediate the lytic destruction of numerous kinds of cells and pathogenic organisms including bacteria, viruses, and virus-infected cells. In addition, the complement system also activates neutrophils, monocytes, basophils, mast cells, and lymphocytes to perform specialized functions. While generally considered to be confined to the effector side of immune reactions, recent evidence indicates that the complement system also directly recognizes and is triggered by a number of bacteria and viruses as well as virus-infected cells in the absence of antibody. In such reactions, complement fulfills the recognition role normally associated with the antibody molecule or immune lymphocyte. The complement system may thus also function as a natural surveillance system operative prior to the induction of specific immunity. Involvement of the complement system in biological reactions has been ascertained by several techniques over the years. These include quantitation of individual complement components in human sera and demonstration of complement deposition in diseased tissues in human diseases and in experimental diseases in animals. Such techniques, however, have limitations in specificity and sensitivity. Assays which detect specific features of the complement activation process have become available in recent years. These tests detect the physical, chemical, or antigenic changes characteristic of the complement activation process. These assays are extremely specific and quantitative; furthermore, most are usable with samples from patients. Three general approaches have been utilized to develop such specific quantitative assays for complement activation. The first includes assays which quantitate activation-specific limited proteolysis of the complement components. The second type of assay includes tests which detect and quantitate new antigens or other activation-specific antigenic changes. The third category is represented by assays which detect and quantitate the protein-protein complexes characteristic of the activation process. Examples of tests presenting each of these approaches are given.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1983

Steroids as immunosuppressants in pregnancy.

In considering the potential of known reproductive hormones to act as immunoregulatory substances during pregnancy, progesterone clearly is an attractive candidate for the following reasons: 1) progesterone is a primitive hormone occurring in virtually all species; 2) it is the only hormone which has been shown to be absolutely essential for maintenance of pregnancy in a variety of mammals, including the human; 3) it has demonstrable in vivo and in vitro immunosuppressive effects when present in concentrations known to be present in the human placenta; 4) it has weak systemic effects compared to cortisol; 5) in many species including primates, it is produced by trophoblastic cells: potential targets of the maternal immune system. Inhibitory effects of progesterone on immune cells have been demonstrated despite the absence of classical steroid receptors for progesterone (Lippman 1979). Specific functions of human T-lymphocytes and macrophages are inhibited by concentrations of progesterone known to occur in the placenta (10(-6)-10(-5) M). Although similar effects are produced by cortisol, clear-cut differences exist in the mechanisms by which cortisol and progesterone act on immune cells. The results suggest, but do not prove, that progesterone does not act on immune cells by binding to the glucocorticoid receptor. This can be considered to be advantageous, for otherwise pregnancy could be associated with glucocorticoid toxicity. Remarkable local anti-inflammatory activity of progesterone has been observed in vivo, although the mechanism of this effect is poorly understood. The striking absence of inflammatory cells in the pregnant uterus until a few days before birth is consistent with known effects of progesterone from animal studies. Whether this regulatory effect on cell traffic is exerted directly by progesterone or by secondary mediators produced within the uterus remains to be determined. In either case, appropriate timing of the removal of progesterone's influence may constitute an integral part of the process of parturition. Post-partum resolution of the placental attachment-site has many of the cellular characteristics of transplant rejection. Furthermore, it has recently been proposed that inflammatory cells which invade the cervix may generate prostaglandins which mediate the biochemical changes that are essential for its dilation to allow escape of the fetus (Liggins 1981). If the processes begin prior to delivery as a consequence either of progesterone withdrawal or inhibition of its activity, parturition may in fact be considered as a delayed rejection process.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗