Migration Of Peripheral Leukocytes Research Articles

Activation of peripheral leukocyte migration before spontaneous labor at term

Activation of peripheral leukocyte migration before spontaneous labor at term

Potential genetic polymorphism of matrix metalloproteinase (MMP)-9 in Iranian migraine patients with Toxoplasma gondii infection.

Toxoplasma gondii is an intracellular protozoan parasite that causes neuroinflammation in the brain and a constant need for peripheral leukocyte migration. Matrix metalloproteinase 9 (MMP-9) can play a major role in this neuroinflammation and be implicated in some neurological disorders, such as migraines. Therefore, the genetic polymorphism evaluation of MMP-9 in migraine patients with T. gondii infection was performed. One hundred fourteen migraine patients and 114 healthy controls were evaluated for the presence of anti-Toxoplasma IgG antibodies. Seventy-two migraine patients and 40 healthy controls were randomly selected for assessment of the MMP 9-1562C/T genetic polymorphism. In the preliminary examination, 61 (53.5%) migraine patients and 43 (37.3%) healthy controls were positive for IgG antibodies, with a significant association between T. gondii seropositivity and migraine (OR = 1.90; 95% CI = 1.21-3.223; P = 0.012). Genetic distribution for the polymorphism was not in Hardy-Weinberg equilibrium in cases but showed no significant variation in control groups (P = 0.03 and P = 0.180, respectively). A significant preponderance of the CT + TT genotype was found in migraine subjects compared to controls (P = 0.042) (OR, 1.77, CI, 1.013-2.229). The homozygote muted allele TT had a higher rate in migraine patients (6.9%). There were significant differences in CT + TT genotype between T. gondii positive and negative migraine patients (P = 0.024), but T allele frequencies had no significant variation (OR 1.7 CI, 1.084-2.44 and 0.42 CI, 0.044-3.97, respectively). In conclusion, the results may provide the first evidence for the involvement of the MMP-9 gene polymorphism in the mechanism of migraine pathology following Toxoplasma infection.

Uncovering the neuroprotective effect of vitamin B12 in pneumococcal meningitis: insights into its pleiotropic mode of action at the transcriptional level.

The interplay between bacterial virulence factors and the host innate immune response in pneumococcal meningitis (PM) can result in uncontrolled neuroinflammation, which is known to induce apoptotic death of progenitor cells and post-mitotic neurons in the hippocampal dentate gyrus, resulting in cognitive impairment. Vitamin B12 attenuates hippocampal damage and reduces the expression of some key inflammatory genes in PM, by acting as an epidrug that promotes DNA methylation, with increased production of S-adenosyl-methionine, the universal donor of methyl. Eleven-day-old rats were infected with S. pneumoniae via intracisternal injection and then administered either vitamin B12 or a placebo. After 24 hours of infection, the animals were euthanized, and apoptosis in the hippocampal dentate gyrus, microglia activation, and the inflammatory infiltrate were quantified in one brain hemisphere. The other hemisphere was used for RNA-Seq and RT-qPCR analysis. In this study, adjuvant therapy with B12 was found to modulate the hippocampal transcriptional signature induced by PM in infant rats, mitigating the effects of the disease in canonical pathways related to the recognition of pathogens by immune cells, signaling via NF-kB, production of pro-inflammatory cytokines, migration of peripheral leukocytes into the central nervous system, and production of reactive species. Phenotypic analysis revealed that B12 effectively inhibited microglia activation in the hippocampus and reduced the inflammatory infiltrate in the central nervous system of the infected animals. These pleiotropic transcriptional effects of B12 that lead to neuroprotection are partly regulated by alterations in histone methylation markings. No adverse effects of B12 were predicted or observed, reinforcing the well-established safety profile of this epidrug. B12 effectively mitigates the impact of PM on pivotal neuroinflammatory pathways. This leads to reduced microglia activation and inflammatory infiltrate within the central nervous system, resulting in the attenuation of hippocampal damage. The anti-inflammatory and neuroprotective effects of B12 involve the modulation of histone markings in hippocampal neural cells.

Skuteczność zastosowania ruksolitynibu u chorej z wtórnym włóknieniem szpiku w przebiegu wieloletniej czerwienicy prawdziwej powikłanej zakrzepicą w układzie wrotnym

The effect of leukaemia-associated antigens prepared from leukaemic lymphoblasts and myeloblasts has been studied on the migration of peripheral leucocytes obtained from children with Down's syndrome. Membrane extract from leukaemic lymphoblasts had no effect, while that from leukaemic myeloblasts was slightly inhibitory, i.e. it was "recognized" as antigen by the lymphocytes of children with Downs syndrome.

Pregnant human peripheral leukocyte migration during several late pregnancy clinical conditions: a cross-sectional observational study

BackgroundParturition at term and preterm is characterized by sterile inflammatory processes occurring in the absence of infection whereby peripheral leukocytes infiltrate gestational tissues in response to chemotactic signals. In response to a homing signal, recruited leukocytes undergo diapedesis and extravasate through capillaries, migrating into stromal tissue. There they interact with resident immune and stromal cells to produce a mixture of matrix metalloproteinases, prostaglandins and cytokines including interleukin-1β (IL-1β) and IL-6 that in turn transform the uterus from pregnancy to parturition. Since migration is an early parturitional event our purpose was to study the migration of maternal peripheral blood leukocytes in response to a standard chemotactic signal during several different conditions of late pregnancy.MethodsWe used a cross-sectional observational study design. Subjects were (sTL) spontaneous normal labour delivered vaginally at term, (TNL) elective caesarean section at term without labour, (PTL) preterm in labour, (PTNL) preterm not in labour, (TPTL) threatened preterm labour, and (pPROM) preterm with premature rupture of membranes. Leukocytes (100,000) obtained by venipuncture and chemotactic factor isolated from term labour fetal membranes were placed in the upper and lower halves, respectively, of a Boyden chamber separated by a filter with 3μm pores. Migrated leukocytes were assessed by flow cytometry. The number of leukocytes that migrated in 90 min was the primary outcome measure.ResultsIncreased numbers of leukocytes from peripheral blood of women in labour (TL or PTL) or soon to go into labour (PPROM) migrated towards a chemotactic signal than did leukocytes from women not in labour (TNL, PTNL, or TPTL) (p < 0.0001). All pPROM delivered within 7d; TPTL delivered >30d. Receiver operating characteristic curve parameters indicated the cut-off point for delivery within 7d to be 37,082 leukocytes with sensitivity 78.1%, specificity 88.9%, positive predictive value 91.4%, negative predictive value 72.7%, and area under the curve 0.83.ConclusionLeukocyte migration to a fetal membrane signal varies in a predictable fashion during various clinical situations of late gestation. This principle has the potential to be improved to become a clinical test to predict delivery.

Peripheral Leukocyte Migration in Ferrets in Response to Infection with Seasonal Influenza Virus.

In order to better understand inflammation associated with influenza virus infection, we measured cell trafficking, via flow cytometry, to various tissues in the ferret model following infection with an A(H3N2) human seasonal influenza virus (A/Perth/16/2009). Changes in immune cells were observed in the blood, bronchoalveolar lavage fluid, and spleen, as well as lymph nodes associated with the site of infection or distant from the respiratory system. Nevertheless clinical symptoms were mild, with circulating leukocytes exhibiting rapid, dynamic, and profound changes in response to infection. Each of the biological compartments examined responded differently to influenza infection. Two days after infection, when infected ferrets showed peak fever, a marked, transient lymphopenia and granulocytosis were apparent in all infected animals. Both draining and distal lymph nodes demonstrated significant accumulation of T cells, B cells, and granulocytes at days 2 and 5 post-infection. CD8+ T cells significantly increased in spleen at days 2 and 5 post-infection; CD4+ T cells, B cells and granulocytes significantly increased at day 5. We interpret our findings as showing that lymphocytes exit the peripheral blood and differentially home to lymph nodes and tissues based on cell type and proximity to the site of infection. Monitoring leukocyte homing and trafficking will aid in providing a more detailed view of the inflammatory impact of influenza virus infection.

Chemokines and chemokine receptors in the pathogenesis of multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory and autoimmune, demyelinating disease of the central nervous system (CNS). Migration of autoreactive T lymphocytes into the CNS is one of the key processes that characterize the pathogenesis of MS and lead to the formation of inflammatory demyelinating CNS lesions. Chemokines represent a family of cytokines. They are low molecular weight soluble proteins, which affect target cells by binding to membrane chemokine receptors. Previous studies on experimental model of MS and experimental clinical studies confirmed that numerous chemokines and chemokine receptors, synthesized by CNS cells and various leukocyte populations, are an important component in the pathogenesis of MS. The essential role of chemokines in MS pathogenesis is to stimulate the migration of peripheral leukocytes into the CNS. In clinical pharmacological studies, it was demonstrated that the impact on expression of chemokines and chemokine receptors represents one of the mechanisms of action of pharmacological immunomodulatory agents used in the treatment of MS. It is difficult to allocate a pharmacological agent that permanently effectively suppresses the disease, and one of the reasons for that is complexity of the network of chemokines and chemokine receptors, in terms of their multitude and their variety of functions. Improved therapeutics that would be produced in the future, by acting through the individual components of complex network of chemokines and chemokine receptors, would selectively influence the migratory properties of pathogenic leukocyte populations, without compromising the functions of other components of the immune system.

Serum from APP/PS1 mice negatively impacts on BBB integrity leading to enhanced macrophage infiltration and exacerbation of inflammation

The blood–brain barrier (BBB) functions to protect the brain from potentially-damaging pathogens and limits the infiltration of peripheral immune cells. It is a complex arrangement of astrocytes and endothelial cells which forms tight junctions and gives the structure its barrier properties. Recent evidence has highlighted the presence of peripheral immune cells in the brain parenchyma of a mouse model of Alzheimer's disease (AD; APP/PS1 mice) while disruption of the BBB and transendothelial migration of peripheral leukocytes have been reported in neuroinflammatory diseases.

Stretch-induced human myometrial cytokines enhance immune cell recruitment via endothelial activation.

Spontaneous term labour is associated with amplified inflammatory events in the myometrium including cytokine production and leukocyte infiltration; however, potential mechanisms regulating such events are not fully understood. We hypothesized that mechanical stretch of the uterine wall by the growing fetus facilitates peripheral leukocyte extravasation into the term myometrium through the release of various cytokines by uterine myocytes. Human myometrial cells (hTERT-HM) were subjected to static mechanical stretch; stretch-conditioned media was collected and analysed using 48-plex Luminex assay and ELISA. Effect of stretch-conditioned media on cell adhesion molecule expression of human uterine microvascular endothelial cells (UtMVEC-Myo) was detected by quantitative polymerase chain reaction (qPCR) and flow cytometry; functional assays testing leukocyte-endothelial interactions: adhesion of leukocytes to endothelial cells and transendothelial migration of calcein-labelled primary human neutrophils as well as migration of THP-1 monocytic cells were assessed by fluorometry. The current in vitro study demonstrated that mechanical stretch (i) directly induces secretion of multiple cytokines and chemokines by hTERT-HM cells (IL-6, CXCL8, CXCL1, migration inhibitory factor (MIF), VEGF, G-CSF, IL-12p70, bFGF and platelet-derived growth factor subunit B (PDGF-bb), P<0.05); stretch-induced cytokines (ii) enhance leukocyte adhesion to the endothelium of the surrounding uterine microvasculature by (iii) inducing the expression of endothelial cell adhesion molecules and (iv) directing the transendothelial migration of peripheral leukocytes. (vi) Chemokine-neutralizing antibodies and broad-spectrum chemokine inhibitor block leukocyte migration. Our data provide a proof of mechanical regulation for leukocyte recruitment from the uterine blood vessels to the myometrium, suggesting a putative mechanism for the leukocyte infiltrate into the uterus during labour and postpartum involution.

T-Cell Production of Matrix Metalloproteinases and Inhibition of Parasite Clearance by TIMP-1 During ChronicToxoplasmaInfection in the Brain

Chronic infection with the intracellular protozoan parasite Toxoplasma gondii leads to tissue remodelling in the brain and a continuous requirement for peripheral leucocyte migration within the CNS (central nervous system). In the present study, we investigate the role of MMPs (matrix metalloproteinases) and their inhibitors in T-cell migration into the infected brain. Increased expression of two key molecules, MMP-8 and MMP-10, along with their inhibitor, TIMP-1 (tissue inhibitor of metalloproteinases-1), was observed in the CNS following infection. Analysis of infiltrating lymphocytes demonstrated MMP-8 and -10 production by CD4+ and CD8+ T-cells. In addition, infiltrating T-cells and CNS resident astrocytes increased their expression of TIMP-1 following infection. TIMP-1-deficient mice had a decrease in perivascular accumulation of lymphocyte populations, yet an increase in the proportion of CD4+ T-cells that had trafficked into the CNS. This was accompanied by a reduction in parasite burden in the brain. Taken together, these findings demonstrate a role for MMPs and TIMP-1 in the trafficking of lymphocytes into the CNS during chronic infection in the brain.

Aggravation of Different Types of Experimental Colitis by Depletion or Adhesion Blockade of Neutrophils

Neutrophils are generally thought to play an important proinflammatory role in the pathogenesis of inflammatory bowel disease. The objective of this study was to evaluate whether blocking the invasion of neutrophils by anti-L-selectin monoclonal antibodies modulates chemically induced colitis and how this modulation is accomplished. Trinitrobenzene sulfonic acid/dinitrobenzene sulfonic acid (TNBS/DNBS)-induced colitis was studied in rats on treatment with anti-L-selectin monoclonal antibodies (mAb) or antineutrophil antiserum. Different anti-L-selectin mAb, either blocking or nonblocking, as well as F(ab)(2) fragments were evaluated. Additionally, leukocyte migration was examined using intravital microscopy. Furthermore, the effect of neutrophil depletion in rat TNBS-induced colitis was studied either prior to or after colitis induction as well as murine CD4(+)CD45RB(high) transfer colitis. Finally, bacterial translocation during DNBS-induced colitis was studied in neutrophil-depleted and control rats. Anti-L-selectin mAb treatment resulted in increased mortality and bowel inflammation as well as hemorrhagic eye secretion. No clear difference was found between blocking and nonblocking mAb or F(ab)(2) fragments. For all investigated antibodies/fragments, either complete blockade of leukocyte invasion or marked neutrophil depletion was found. Accordingly, neutrophil depletion by antiserum resulted in aggravation of rat DNBS-induced colitis as well as murine transfer colitis. Adhesion blockade or neutrophil depletion aggravates rat TNBS/DNBS-induced colitis together with extraintestinal manifestations of the eyes. Therefore, neutrophils appear to have an important role in mucosal repair processes. Importantly, adhesion blockade as a therapeutic concept can be detrimental in inflammatory bowel disease.

Intrathecal clonidine suppresses zymosan-induced peripheral leukocyte migration in a mouse air pouch model via activation of spinal muscarinic type 2 receptors and sympathoadrenal medullary activity

These studies were performed to examine the potential anti-inflammatory effect of intrathecal (IT) clonidine (an α 2-adrenoceptor agonist) on zymosan-induced leukocyte migration in a mouse air pouch model. IT clonidine dose-dependently suppressed zymosan-induced leukocyte migration and this effect was blocked by IT idazoxan (an α 2-adrenoceptor antagonist) pretreatment. Since a number of studies have previously shown that spinal α 2-adrenoceptors are functionally associated with spinal cholinergic activity, we next examined whether spinal acetylcholine (ACh) receptors were also involved in mediating this anti-inflammatory effect of IT clonidine. IT pretreatment with atropine (a muscarinic receptor antagonist), but not hexamethonium (a nicotinic receptor antagonist) completely blocked the anti-migratory effect of IT clonidine. Subsequent experiments showed that IT pretreatment with methoctramine (a muscarinic M 2 antagonist), but not pirenzepine (an M 1 antagonist) or 4-DAMP (an M 3 antagonist), suppressed clonidine's anti-inflammatory effect. Finally, we studied the potential roles of the sympathetic nervous system and the hypothalamo-pituitary–adrenal axis in clonidine's anti-inflammatory effect. Adrenalectomy or systemic injection of propranolol (a β-adrenoceptor antagonist) blocked clonidine's effect. However, pretreatment with RU486 (a corticosteroid antagonist) or peripheral sympathetic denervation using 6-hydroxydopamine had no effect. Furthermore, IT clonidine increased Fos expression in zymosan treated mice exclusively in T7–T11 sympathetic preganglionic neurons (which mainly project to the adrenal medulla), but not those of the T1–T6 or T12–L2 spinal segments. Moreover, IT methoctramine significantly reduced this increase in Fos expression. Collectively, these findings suggest that IT clonidine suppresses peripheral leukocyte migration via a sympathoadrenal medullary pathway, and that this suppressive effect is mediated by spinal M 2 receptors.

Segregation of lipid raft markers including CD133 in polarized human hematopoietic stem and progenitor cells

AbstractDuring ontogenesis and the entire adult life hematopoietic stem and progenitor cells have the capability to migrate. In comparison to the process of peripheral leukocyte migration in inflammatory responses, the molecular and cellular mechanisms governing the migration of these cells remain poorly understood. A common feature of migrating cells is that they need to become polarized before they migrate. Here we have investigated the issue of cell polarity of hematopoietic stem/progenitor cells in detail. We found that human CD34+ hematopoietic cells (1) acquire a polarized cell shape upon cultivation, with the formation of a leading edge at the front pole and a uropod at the rear pole; (2) exhibit an amoeboid movement, which is similar to the one described for migrating peripheral leukocytes; and (3) redistribute several lipid raft markers including cholesterol-binding protein prominin-1 (CD133) in specialized plasma membrane domains. Furthermore, polarization of CD34+ cells is stimulated by early acting cytokines and requires the activity of phosphoinositol-3-kinase as previously reported for peripheral leukocyte polarization. Together, our data reveal a strong correlation between polarization and migration of peripheral leukocytes and hematopoietic stem/progenitor cells and suggest that they are governed by similar mechanisms.

Automated perimetry in glaucoma--room for improvement?

Cell-mediated immunity is a subject of intense interest in parasitology. Experiments with animals and observations on humans suggest that cell-mediated immunity is involved in protozoal infections (1). The inhibition of leukocyte migration has proved a suitable method for the <i>in vitro</i> study of cellular immunology. Søborg and Bendixen (2, 3) have successfully used this test with human peripheral leukocytes; Rosenberg and David (4) have shown it applicable to soluble antigens. In the present work we have attempted to obtain an <i>in vitro</i> test of the immune mechanisms in American trypanosomiasis. We observed the <i>in vitro</i> migration of peripheral leukocytes from patients with positive serology for <i>Trypanosoma cruzi</i> infection against soluble antigen. Materials and Methods. Blood. Two samples from each of 30 human adults were drawn: one, with heparin (Abbott 5000 U/ml with benzyl alcohol preservative) for the migration test, the other for the serologic tests.

Tick-borne fever: Leucocyte migration inhibition

When sheep were infected with Cytoecetes phagocytophila the in vitro migration of peripheral leucocytes was reduced even when antigen was not added. The inhibition of migration coincided with parasitaemia and was due to soluble factors which inhibited the migration of leucocytes from normal sheep. After the cessation of parasitaemia addition of antigen was necessary for migration inhibition to occur.

Macrophage migration stimulation factor.

Macrophage migration stimulation factor.

Cell-mediated immune response in gonococcal infection.

A peripheral leukocyte migration inhibition test has been used to demonstrate cellular immunity to a protein component of Neisseria gonorrhoeae. Human leukocytes served as effector cells in an agarose method to distinguish antigen-sensitive from nonsensitive individuals. Leukocytes, preincubated with antigen, were placed in wells in medium 199 agarose. After 18 h of incubation the migration index was calculated by dividing the area of migration of cells preincubated with antigen by the area of migration of the control cells. Significant migration inhibition was demonstrated for 16 of the 30 patients with uncomplicated gonorrhoea. Maximum inhibition was obtained 7-10 days following the onset of symptoms and the duration of the response varied from 14 to more than 40 days. There was a statistically significant positive correlation between the number of previous infections and migration inhibition. A control group, which included individuals with Neisseria meningitidis infection, showed an insignificant response to this gonococcal antigen. Although these results indicate the presence of cell-mediated immunity, the significance of this response in the protection of the host or in the pathogenesis of gonococcal disease has yet to be determined.

Leucocyte migration test with autologous colonic mucosa as antigen in patients with ulcerative colitis.

The leucocyte migration agarose technique (LMAT) was applied in a study of the migration of peripheral leucocytes in 16 patients with ulcerative colitis using three different autologous types of tissue as antigen: rectal mucosa, skin and buccal mucosa. In all cases the migration indices were within normal limits, and they did not differ from a group of control patients suffering from peptic ulcer, irritable colon or haemorrhoidal tumours. The present study does not support the theory of cellular hypersensitivity against colonic mucosa in patients with ulcerative colitis.

Cell-mediated immunity in tropical theileriasis (Theileria anmilata infection)

Migration of peripheral leucocytes collected from Theileria annulata carrier cattle was inhibited in the presence of piroplasmal antigen. The degree of inhibition was antigen density dependent. The same antigen did not inhibit migration of leucocytes obtained from clean animals, raised under tick-free conditions. The carrier animals exhibited typical skin sensitivity reaction on intradermal inocluation of the piroplasmal antigen. The known negative animals failed to evince a similar reaction.

Leucocyte migration test with autologous colonic mucosa as antigen in patients with ulcerative colitis.

The leucocyte migration agarose technique (LMAT) was applied in a study of the migration of peripheral leucocytes in 16 patients with ulcerative colitis using three different autologous types of tissue as antigen: rectal mucosa, skin and buccal mucosa. In all cases the migration indices were within normal limits, and they did not differ from a group of control patients suffering from peptic ulcer, irritable colon, or haemorrhoidal tumours. The present study does not support the theory of cellular hypersensitivity against colonic mucosa in patients with ulcerative colitis.