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Adhesive interactions of leukocytes and endothelial cells initiate leukocyte migration to inflamed tissue and are important for immune surveillance. Acute and chronic inflammatory diseases show a dysregulated immune response and result in a massive efflux of leukocytes that contributes to further tissue damage. Therefore, targeting leukocyte trafficking may provide a potent form of anti-inflammatory therapy. Leukocyte migration is initiated by interactions of the cell adhesion molecules E-, L-, and P-selectin and their corresponding carbohydrate ligands. Compounds that efficiently address these interactions are therefore of high therapeutic interest. Based on this rationale we investigated synthetic dendritic polyglycerol sulfates (dPGS) as macromolecular inhibitors that operate via a multivalent binding mechanism mimicking naturally occurring ligands, dPGS inhibited both leukocytic L-selectin and endothelial P-selectin with high efficacy. Size and degree of sulfation of the polymer core determined selectin binding affinity. Administration of dPGS in a contact dermatitis mouse model dampened leukocyte extravasation as effectively as glucocorticoids did and edema formation was significantly reduced. In addition, dPGS interacted with the complement factors C3 and C5 as was shown in vitro and reduced C5a levels in a mouse model of complement activation. Thus, dPGS represent an innovative class of a fully synthetic polymer therapeutics that may be used for the treatment of inflammatory diseases. anti-inflammatory drug | complement inhibition | multiple target binding | multivalent selectin inhibitor | synthetic polymer doi/ 10.1073/pnas.1003103107

Exposure of esophageal mueosa to hydrochloric acid (HC1) is a crucial factor in the pathogenesis of reflux disease. We examined supernatant of HC1-exposed rabbit mucosa for inflammatory mediators enhancing migration of leukocytes and production of [H.sub.2][O.sub.2] as an indicator of leukocyte activation. A tubular segment of rabbit esophageal mucosa was tied at both ends to form a sac, which was filled with HC1-acidified Krebs buffer at pH 5 (or plain Krebs buffer as control) and kept oxygenated at 37[degrees]C. The medium around the sac (supernatant) was collected after 3 h. Rabbit peripheral blood leukocytes (PBL) were isolated, and sac supernatant was used to investigate PBL migration and [H.sub.2][O.sub.2] production. HCl-exposed esophageal mucosa released substance P (SP), CGRP, platelet-activating factor (PAF), and IL-8 into the supernatant. PBL migration increased in response to IL-8 or to supernatant of the HCl-filled mucosal sac. Supernatant-induced PBL migration was inhibited by IL-8 antibodies and by antagonists for PAF (CV3988) or neurokinin 1 (i.e., SP), but not by a CGRP antagonist. Supernatant of the HCl-filled mucosal sac increased [H.sub.2][O.sub.2] release by PBL that was significantly reduced by CV3988 and by a SP antagonist but was not affected by IL-8 antibodies or by a CGRP antagonist. We conclude that IL-8, PAF, and SP are important inflammatory mediators released by esophageal mucosa in response to acid that promote PBL migration. In addition, PAF and SP induce production of [H.sub.2][O.sub.2] by PBL. These findings provide a direct link between acid exposure and recruitment and activation of immune cells in esophageal mucosa. PAF; substance P; IL-8; gastroesophageal reflux doi: 10.1152/ajpgi.00160.2010.

In order to verify the survival biomarker role of several immune functions, and to determine the oxidation and inflammation mechanisms underlying variability in the aging process, we have investigated a variety of immune functions and oxidative stress parameters as well as activation of the nuclear factor kappa B (NF[kappa]B) in peritoneal leukocytes from four different age groups of mice, including natural extreme longevity. Immune cells from naturally long-lived animals showed preservation of immune function in response to stimuli and controlled oxidative stress as well as nuclear factor kappa B activation in resting conditions. Moreover, leukocytes from extreme long-lived animals showed increased catalase activity when compared with the adults. In contrast, the old and very old animal groups showed impaired immune function and increased oxidation as well as NF[kappa]d3 activation. Our results support preserved immune function as a biomarker of extended survival and point to controlled regulation of NF[kappa]B activity as a key mechanism restraining oxidative stress in immune cells and contributing to reach longevity. Key Words: Aging--Immune function--Longevity--NF[kappa]B--Oxidative stress. doi: 10.1093/gerona/glq101

Intestinal mucosal integrity is dependent on epithelial function and a regulated immune response to injury. Fucosyltransferase VII (Fuc-TVII) is an essential enzyme required for the expression of the functional ligand for E- and P-selectin. Trefoil factor 3 (TFF3) is involved in both protecting the intestinal epithelium against injury as well as aiding in wound repair following injury. The aim of the present study was to assess the interplay between barrier function and leukocyte recruitment in intestinal inflammation. More specifically, we aimed to examine how targeted disruption of Fuc-TVII either in wild-type or [TFF3.sup.-/-] mice would alter their susceptibility to colonic injury. TFF3 and Fuc-TVII double-knockout mice (TFF3/Fuc-[TVII.sup.-/-] mice) were generated by mating [TFF3.sup.-/-] and Fuc-[TVII.sup.-/-] mice. Colitis was induced by administration of dextran sodium sulfate (DSS) (2.5% wt/vol) in the drinking water. Changes in baseline body weight, diarrhea, and fecal blood were assessed daily. Upon euthanasia, extents of colonic inflammation were assessed macroscopically, microscopically, and through quantification of myeloperoxidase (MPO) activity. Colonic lymphocyte subpopulations were assessed at 6 days after administration of DSS by flow cytometry and immunohistochemistry. No baseline intestinal inflammation was found in TFF3/Fuc-[TVII.sup.-/-] [TFF3.sup.-/-], Fuc-[TVII.sup.-/-], or wild-type mice. Loss of Fuc-TVII resulted in a reduction in disease severity whereas [TFF3.sup.-/-] mice were markedly more susceptible to DSS-induced colitis. Remarkably, the loss of Fuc-TVII in [TFF3.sup.-/-] mice markedly decreased the severity of DSS-induced colitis as evidenced by reduced weight loss, diarrhea, decreased colonic MPO levels and improved survival. Furthermore, the loss of TFF3 resulted in increased severity of spontaneous colitis in IL-2/[beta-microglobulin-deficient mice. These studies highlight the importance of the interplay between factors involved in the innate immune response, mucosal barrier function, and genes involved in regulating leukocyte recruitment and other aspects of the immune response. trefoil factor family 3 doi: 10.1152/ajpgi.00228.2009.

In atherosclerosis, chemokines recruit circulating mononuclear leukocytes to the vascular wall. A key factor is [CX.sub.3]CL1, a chemokine with soluble and transmembrane species that acts as both a chemoattractant and an adhesion molecule. Thromboxane [A.sub.2] and its receptor, TP, are also critical to atherogenesis by promoting vascular inflammation and consequent leukocyte recruitment. We examined the effects of TP stimulation on processing and function of [CX.sub.3]CL1, using [CX.sub.3]CL1-expressing human ECV-304 cells and primary human vascular endothelial cells. TP agonists promoted rapid shedding of cell surface [CX.sub.3]CL1, which was inhibited by pharmacological inhibitors or specific small interfering RNA targeting tumor necrosis factor-[alpha]-converting enzyme (TACE). Because it reduced cell surface [CX.sub.3]CL1, we predicted that TP stimulation would inhibit adhesion of leukocytes expressing the [CX.sub.3]CL1 cognate receptor but, paradoxically, saw enhanced adhesion. We questioned whether the enhanced ability of the remaining membrane-associated [CX.sub.3]CL1 to bind targets was caused by changes in its lateral mobility. Using fluorescence recovery after photobleaching, we found that plasmalemmal [CX.sub.3]CL1 was initially tethered but ultimately mobilized by TP agonists. TP stimulation provoked clustering of transmembrane [CX.sub.3]CL1 at sites of contact with adherent leukocytes. These data demonstrate that TP stimulation induces two distinct effects: a rapid cleavage of surface [CX.sub.3]CL1, thereby releasing the soluble chemoattractant, plus mobilization of the remaining transmembrane [CX.sub.3]CL1 to enhance the avidity of interactions with adherent leukocytes. The dual effect of TP allows [CX.sub.3]CL1 to recruit leukocytes to sites of vascular inflammation while enhancing their adhesion once recruited. leukocytes; inflammation; endothelial cells doi: 10.1152/ajpcell.00380.2009.

The insulin-like growth factor (IGF) axis may affect immune cell replicative potential and telomere dynamics. Among 551 adults 65 years and older, leukocyte telomere length (LTL), insulin-like growth factor-I (IGF-I), and insulin-like growth factor--binding proteins 1 and 3 (IGFBP-1, IGFBP-3) were measured. Multivariate linear regression was used to model the association of LTL with IGF-1 and IGFBPs, while controlling for confounding and increasing precision by adjusting for covariates. We observed a significant association between higher IGF-1 and longer LTL after adjustment for age, sex, race, smoking status, body mass index, hypertension, diabetes, and serum lipids. The results suggested an increase of .08 kb in LTL for each standard deviation increase of IGF-I (p = .04). IGFBP-1 and 1GFBP-3 were not significantly associated with LTL. High IGF-1 may be an independent predictor of longer LTL, consistent with prior evidence suggesting a role for IGF-1 in mechanisms relating to telomere maintenance. Key Words: Insulin-like growth factor--Telomere length--Epidemiology. doi: 10.1093/gerona/glp036

GPR109B (HM74) is a putative G protein-coupled receptor (GPCR) whose cognate ligands have yet to be characterized. GPR109B shows a high degree of sequence similarity to GPR109A, another GPCR that was identified as a high-affinity nicotinic acid (niacin) receptor. However, the affinity of nicotinic acid to GPR109B is very low. In this study, we found that certain aromatic D-amino acids, including D-phenylalanine, D-tryptophan, and the metabolite of the latter, D-kynurenine, decreased the activity of adenylate cyclase in cells transfected with GPR109B cDNA through activation of pertussis toxin (PTX)-sensitive G proteins. These D-amino acids also elicited a transient rise of intracellular [Ca.sup.2+] level in cells expressing GPR109B in a PTX-sensitive manner. In contrast, these D-amino acids did not show any effects on cells expressing GPR109A. We found that the GPR109B mRNA is abundantly expressed in human neutrophils. D-phenylalanine and D-tryptophan induced a transient increase of intracellular [Ca.sup.2+] level and a reduction of cAMP levels in human neutrophils. Furthermore, knockdown of GPR109B by RNA interference inhibited the D-amino acids-induced decrease of cellular cAMP levels in human neutrophils. These D-amino acids induced chemotactic activity of freshly prepared human neutrophils. We also found that D-phenylalanine and D-tryptophan induced chemotactic responses in Jurkat cells transfected with the GPR109B cDNA but not in mock-transfected Jurkat cells. These results suggest that these aromatic D-amino acids elicit a chemotactic response in human neutrophils via activation of GPR109B. D-kynurenine | D-phenylalanine | D-tryptophan | nicotinic acid (niacin) | orphan receptor

Hydrogen sulfide ([H.sub.2]S) is one of three endogenous gases, along with carbon monoxide (CO) and nitric oxide (NO), that exert a variety of important vascular actions in vivo. Although it has been demonstrated that CO or NO can trigger the development of a preconditioned phenotype in postischemic tissues, it is unclear whether [H.sub.2]S may also induce protection in organs subsequently exposed to ischemia-reperfusion (I/R). In light of these observations, we postulated that preconditioning with the exogenous [H.sub.2]S donor sodium hydrosulfide (NaHS-PC) would inhibit leukocyte rolling (LR) and adhesion (LA) induced by I/R. We used intravital microscopic techniques to demonstrate that NaHS-PC 24 h, but not 1 h, before I/R causes postcapillary venules to shift to an anti-inflammatory phenotype in wild-type (WT) mice such that these vessels fail to support LR and LA during reperfusion. The protective effect of NaHS-PC on LR was largely abolished by coincident pharmacological inhibition of NO synthase (NOS) in WT animals and was absent in endothelial NOS-deficient ([eNOS.sup.-/-]) mice. A similar pattern of response was noted in WT mice treated concomitantly with NaHS plus p38 mitogen-activated protein kinase (MAPK) inhibitors (SB 203580 or SK-86002). Whereas the reduction in LA induced by antecedent NaHS was attenuated by pharmacological inhibition of NOS or p38 MAPK in WT mice, the antiadhesive effect of NaHS was still evident in [eNOS.sup.-/-] mice. Thus NaHS-PC prevents LR and LA by triggering the activation of an eNOS- and p38 MAPK-dependent mechanism. However, the role of eNOS in the antiadhesive effect of NaHS-PC was less prominent than its effect to reduce LR. ischemia; reperfusion; sodium hydrosulfide; endothelial nitric oxide synthase-deficient mice; leukocyte rolling; leukocyte adhesion

Hypercholesterolemia is associated with phenotypic changes in endothelial cell function that lead to a proinflammatory and prothrombogenic state in different segments of the microvasculature. CD40 ligand (CD40L) and its receptor CD40 are ubiquitously expressed and mediate inflammatory responses and platelet activation. The objective of this study was to determine whether CD40/CD40L, in particular T-cell CD40L, contributes to microvascular dysfunction induced by hypercholesterolemia. Intravital microscopy was used to quantify blood cell adhesion in cremasteric postcapillary venules, endothelium-dependent vasodilation responses in arterioles, and microvascular oxidative stress in wild-type (WT) C57BL/6, CD40-deficient (-/-), [CD40L.sup.-/-], or severe combined immune deficient (SCID) mice placed on a normal (ND) or high-cholesterol (HC) diet for 2 wk. WT-HC mice exhibited an exaggerated leukocyte and platelet recruitment in venules and impaired vasodilation responses in arterioles compared with ND counterparts. A deficiency of CD40, CD40L, or lymphocytes attenuated these responses to HC. The HC phenotype was rescued in [CD40L.sup.-/-] and SCID mice by a transfer of WT T cells. Bone marrow chimeras revealed roles for both vascular- and blood cell-derived CD40 and CD40L in the HC-induced vascular responses. Hypercholesterolemia induced an oxidative stress in both arterioles and venules of WT mice, which was abrogated by either CD40 or CD40L deficiency. The transfer of WT T cells into [CD40L.sup.-/-] mice restored the oxidative stress. These results implicate CD40/CD40L interactions between circulating cells and the vascular wall in both the arteriolar and venular dysfunction elicited by hypercholesterolemia and identify T-cell-associated CD40L as a key mediator of these responses. T lymphocytes; platelets; oxidative stress; arteriolar vasodilation; leukocyte adhesion

Although previous studies have implicated lymphocytes in the gut microvascular and inflammatory responses to ischemia-reperfusion (I/R), the lymphocyte population and lymphocyte-derived products that mediate these responses have not been defined. Platelet and leukocyte adhesion was measured in intestinal postcapillary venules of wild-type (WT) mice and mice genetically deficient in either CD4+ T cells ([CD4.sup.-/-]), CD8+ T cells ([CD8.sup.-/-]), B cells (B [cell.sup.-/-]), or interferon-[gamma] (IFN-[[gamma].sup.-/-]) subjected to 45 min of ischemia and 4 h of reperfusion. The I/R-induced platelet and leukocyte recruitment responses were also evaluated following adoptive transfer of WT splenocytes into [CD4.sup.-/-], [CD8.sup.-/-], B [cell.sup.-/-], and IFN-[[gamma].sup.-/-] mice. WT mice exposed to gut I/R exhibited significant increases in the adhesion of both platelets and leukocytes, compared with sham-WT mice. These blood cell adhesion responses to I/R were greatly attenuated in [CD4.sup.-/-], [CD8.sup.-/-], B [cell.sup.-/-], and IFN-[[gamma].sup.-/-] mice. Adoptive transfer of WT splenocytes restored the WT responses to I/R in all mutants except the B [cell.sup.-/-] mice. These findings implicate both T and B cells and lymphocyte-derived IFN-[gamma] as mediators of the proinflammatory and prothrombogenic phenotype assumed by intestinal microvessels after I/R. inflammation; microcirculation; cytokine; platelet-leukocyte adhesion

Mechanical properties of neutrophils have been recognized as key contributors to stabilizing neutrophil rolling on the endothelium during the inflammatory response. In particular, accumulating evidence suggests that surface protrusion and tether extraction from neutrophils facilitate stable rolling by relieving the disruptive forces on adhesive bonds. Using a customized optical trap setup, we applied piconewton-level pulling forces on targeted receptors that were located either on the microvillus tip (CD162) or intermicrovillus surface of neutrophils (CD18 and CD44). Under a constant force-loading rate, there always occurred an initial tent-like surface protrusion that was terminated either by rupture of the adhesion or by a 'yield' or 'crossover' to tether extraction. The corresponding protrusional stiffness of neutrophils was found to be between 0.06 and 0.11 pN/nm, depending on the force-loading rate and the cytoskeletal integrity, but not on the force location, the medium osmolality, nor the temperature increase from 22[degrees]C to 37[degrees]C. More importantly, we found that neutrophil surface protrusion was accompanied by force relaxation and hysteresis. In addition, the crossover force did not change much in the range of force-loading rates studied, and the protrusional stiffness of lymphocytes was similar to that of neutrophils. These results show that neutrophil surface protrusion is essentially viscoelastic, with a protrusional stiffness that stems primarily from the actin cortex, and the crossover force is independent of the receptor-cytoskeleton interaction. leukocyte rolling; optical trap; cell adhesion; microvillus; micropipette aspiration

We have recently identified the archaic cytokine macrophage migration inhibitory factor (MIF) as a non-canonical ligand of the CXC chemokine receptors CXCR2 and CXCR4 in inflammatory and atherogenic cell recruitment. Because its affinity for CXCR2 was particularly high, we hypothesized that MIF may feature structural motives shared by canonical CXCR2 ligands, namely the conserved N-terminal Glu-Leu-Arg (ELR) motif. Sequence alignment and structural modeling indeed revealed a pseudo-(E)LR motif (Asp-44-X-Arg-11) constituted by non-adjacent residues in neighboring loops but with identical parallel spacing as in the authentic ELR motif. Structure-function analysis demonstrated that mutation of residues R11, D44, or both preserve proper folding and the intrinsic catalytic property of MIF but severely compromises its binding to CXCR2 and abrogates MIF/CXCR2-mediated functions in chemotaxis and arrest of monocytes on endothelium under flow conditions. R11A-MIF and the R11A/D44A-MIF double-mutant exhibited a pronounced defect in triggering leukocyte recruitment to early atherosclerotic endothelium in carotid arteries perfused ex vivo and upon application in a peritonitis model. The function of D44A-MIF in peritoneal leukocyte recruitment was preserved as a result of compensatory use of CXCR4. In conjunction, our data identify a pseudo-(E)LR motif as the structural determinant for MIF's activity as a non-canonical CXCR2 ligand, epitomizing the structural resemblance of chemokine-like ligands with chemokines and enabling selective targeting of pro-inflammatory MIF/CXCR2 interactions. atherosclerosis | CXC chemokine | cytokine | [ELR.sup.+] chemokine

Hydrogen sulfide ([H.sub.2]S) is an endogenous gaseous mediator with the ability to modulate tissue inflammation and pain. The aim of this study was to determine the effect of an [H.sub.2]S donor ([Na.sub.2]S) on leukocyte-endothelium interactions, blood flow, and pain sensation in acutely inflamed knee joints. Acute arthritis was induced in urethane anesthetized C57bl/6 mice by intra-articular injection of kaolin/carrageenan (24-h recovery), and the effect of local administration of [Na.sub.2]S on leukocyte trafficking was measured by intravital microscopy. Synovial blood flow was measured in inflamed knees by laser Doppler perfusion imaging. Finally, the effect of an intra-articular injection of [Na.sub.2]S on joint pain in control and inflamed rats was determined by hindlimb incapacitance and yon Frey hair algesiometry. Local administration of an [H.sub.2]S donor to inflamed knees caused a dose-dependent reduction in leukocyte adherence and an increase in leukocyte velocity. These effects could be inhibited by coadministration of the ATP-sensitive [K.sup.+] channel blocker glibenclamide. Local administration of [Na.sub.2]S to inflamed joints caused a pronounced vasoconstrictor response: however, there was no observable effect of [Na.sub.2]S on joint pain. These findings establish [H.sub.2]S as a novel signaling molecule in rodent knee joints. [H.sub.2]S exhibits potent anti-inflammatory properties, hut with no detectable effect on joint pain. arthritis; blood flow; intravital microscopy; potassium channels

To assess the hypothesis that gap junctions (GJs) participate on leukocyte-endothelium interactions in the inflammatory response, we compared leukocyte adhesion and transmigration elicited by cytokine stimulation in the presence or absence of GJ blockers in the hamster cheek pouch and also in the cremaster muscle of wild-type (WT) and endothelium-specific connexin 43 (Cx43) null mice ([Cx43e.sup.-/-]). In the cheek pouch, topical tumor necrosis factor-[alpha] (TNF-[alpha]; 150 ng/ml, 15 min) caused a sustained increment in the number of leukocytes adhered to venular endothelium (LAV) and located at perivenular regions (LPV). Superfusion with the GJ blockers 18-[alpha]-glycyrrhetinic acid (AGA; 75 [micro]M) or 18-[beta]-glycyrrhetinic acid (50 [micro]M) abolished the TNF-[alpha]-induced increase in LAV and LPV; carbenoxolone (75 [micro]M) or oleamide (100 [micro]M) reduced LAV by 50 and 75%, respectively, and LPV to a lesser extent. None of these GJ blockers modified venular diameter, blood flow, or leukocyte rolling. In contrast, glycyrrhizin (75 [micro]M), a non-GJ blocker analog of AGA, was devoid of effect. Interestingly, when AGA was removed 90 min after TNF-[alpha] stimulation, LAV started to rise at a similar rate as in control. Conversely, application of AGA 90 rain after TNF-[alpha] reduced the number of previously adhered cells. In WT mice, intrascrotal injection of TNF-[alpha] (0.5 [micro]g/0.3 ml) increased LAV (fourfold) and LPV (threefold) compared with saline-injected controls. In contrast to the observations in WT animals, TNF-[alpha] stimulation did not increase LAV or LPV in [Cx43e.sup.-/-] mice. These results demonstrate an important role for GJ communication in leukocyte adhesion and transmigration during acute inflammation in vivo and further suggest that endothelial Cx43 is key in these processes. inflammation; tumor necrosis factor-[alpha]; endothelial-connexin 43 knockout mice; gap junction blockers

Two key characteristics of the inflammatory response are the recruitment of leukocytes to inflamed tissue as well as changes in vessel permeability. We explored the relationship between these two processes using intravital confocal microscopy in cremasters of anesthetized (65 mg/kg Nembutal ip) mice. We provide direct evidence that intercellular adhesion molecule-1 (ICAM-1) links leukocyte-endothelial cell interactions and changes in solute permeability ([P.sub.s]). Importantly, we show that arterioles, not just venules, respond to proinflammatory stimuli, thus contributing to microvascular exchange. We identified two independent, ICAM-1-mediated pathways regulating [P.sub.s]. Under control conditions in wild-type (WT) mice, there is a constitutive PKC-dependent pathway ([P.sub.s] = 1.0 [+ or -] 0.10 and 2.2 [+ or -] 0.46 x [10.sup.-6] cm/s in arterioles and venules, respectively), which was significantly reduced in ICAM-1 knockout (KO) mice ([P.sub.s] = 0.54 [+ or -] 0.07 and 0.77 [+ or -] 0.11 x [10.sub.-6] cm/s). The PKC inhibitor hisindolylmaleimid 1 (1 [micro]mol/l in 0.01% DMSO) decreased [P.sub.s] in WT mice to levels similar to those in ICAM-1 KO mice. Likewise, a PKC activator (phorbol-12-myristate-acetate; 1 [micro]mol/l in 0.01% DMSO) successfully restored [P.sub.s] in ICAM-1 KO vessels to be not different from that of the WT controls. On the other hand, during TNF-[alpha]-induced inflammation, [P.sub.s] in WT mice was significantly increased (2-fold in venules and 2.5-fold in arterioles) in a Src-dependent and PKC-independent manner. The blockade of Src (PP2; 2 [micro]mol/l in 0.01% DMSO) but not PKC significantly reduced the TNF-[alpha]-dependent increase in [P.sub.s]. We conclude that ICAM-1 plays an essential role in the regulation of [P.sub.s] in microvessels and that there are two separate (constitutive and inducible) signaling pathways that regulate permeability under normal and inflamed conditions. adhesion molecules; microvascular exchange

Glucose metabolism is vital to most mammalian cells, and the passage of glucose across cell membranes is facilitated by a family of integral membrane transporter proteins, the GLUTs. There are currently 14 members of the SLC2 family of GLUTs, several of which have been the focus of this series of reviews. The subject of the present review is GLUT3, which, as implied by its name, was the third glucose transporter to be cloned (Kayano T, Fukumoto H, Eddy RL, Fan YS, Byers MG, Shows TB, Bell GI. J Biol Chem 263: 15245-15248, 1988) and was originally designated as the neuronal GLUT. The overriding question that drove the early work on GLUT3 was why would neurons need a separate glucose transporter isoform? What is it about GLUT3 that specifically suits the needs of the highly metabolic and oxidative neuron with its high glucose demand? More recently, GLUT3 has been studied in other cell types with quite specific requirements for glucose, including sperm, preimplantation embryos, circulating white blood cells, and an array of carcinoma cell lines. The last are sufficiently varied and numerous to warrant a review of their own and will not be discussed here. However, for each of these cases, the same questions apply. Thus, the objective of this review is to discuss the properties and tissue and cellular localization of GLUT3 as well as the features of expression, function, and regulation that distinguish it from the rest of its family and make it uniquely suited as the mediator of glucose delivery to these specific cells. neurons: sperm: preimplantation embryo; white blood cells

Polymorphonuclear leukocytes (PMNs) play an important role during inflammation in cardiovascular diseases. Human neutrophil peptides (HNPs) are released from PMN granules upon activation and are conventionally involved in microbial killing. Recent studies suggested that HNPs may be involved in the pathogenesis of vascular abnormality by modulating inflammatory responses and vascular tone. Since HNPs directly interact with endothelium upon release from PMNs in the circulation, we tested the hypothesis that the stimulation with HNPs of endothelial cells modulates the expression of vasoactive by-products through altering cyclooxygenase (COX) activity. When human umbilical vein endothelial cells were stimulated with purified HNPs, we observed a time- and dose-dependent increase in the expression of COX-2, whereas COX-1 levels remained unchanged. Despite an increased expression of COX-2 at the protein level, HNPs did not significantly enhance the COX-2 activity, thus the production of the prostaglandin [PGI.sub.2]. HNPs significantly induced the release of endothelin-1 (ET-1) as well as the formation of nitrotyrosine. The HNP-induced COX-2 and ET-1 production was attenuated by the treatment with the oxygen free radical scavenger N-acetyl-L-cysteine and the inhibitors of p38 MAPK and NF-[kappa]B, respectively. The angiontensin II pathway did not seem to be involved in the HNP-induced upregulation of COX-2 and ET-1 since the use of the angiotensin-converting enzyme inhibitor enalapril had no effect in this context. In conclusion, HNP may play an important role in the pathogenesis of inflammatory cardiovascular diseases by activating endothelial cells to produce vasoactive by-products as a result of oxidative stress. inflammation; immunity; leukocyte

Stromal cell-derived factor-1 (SDF-1; CXCL12), a CXC chemokine, has been found to be involved in inflammation models in vivo and in cell adhesion, migration, and chemotaxis in vitro. This study aimed to determine whether exogenous SDF-1 induces leukocyte recruitment in mice. After systemic administration of SDF-1[alpha], expression of the adhesion molecules P-selectin and VCAM-1 in mice was measured using a quantitative dual-radiolabeled Ab assay and leukocyte recruitment in various tissues was evaluated using intravital microscopy. The effect of local SDF-1[alpha] on leukocyte recruitment was also determined in cremaster muscle and compared with the effect of the cytokine TNF[alpha] and the CXC chemokine keratinocyte-derived chemokine (KC; CXCL1). Systemic administration of SDF-1[alpha] (10 [micro]g, 4-5 h) induced upregulation of P-selectin, but not VCAM-1, in most tissues in mice. It caused modest leukocyte recruitment responses in microvasculature of cremaster muscle, intestine, and brain, i.e., an increase in flux of rolling leukocytes in cremaster muscle and intestines, leukocyte adhesion in all three tissues, and emigration in cremaster muscle. Local treatment with SDF-1[alpha] (1 [micro]g, 4-5 h) reduced leukocyte rolling velocity and increased leukocyte adhesion and emigration in cremasteric venules, but the responses were much less profound than those elicited by KC or TNF[alpha]. SDF-1 s-induced recruitment was dependent on endothelial P-selectin, but not P-selectin on platelets. We conclude that the exogenous SDF-1[alpha] enhances leukocyte-endothelial cell interactions and induces modest and endothelial P-selectin-dependent leukocyte recruitment. inflammation; emigration; adhesion

Cell adhesion, mediated by specific receptor-ligand interactions, plays an important role in biological processes such as tumor metastasis and inflammatory cascade. For example, interactions between [[beta].sub.2]-integrin (lymphocyte function-associated antigen-1 and/or Mac-l) on polymorphonuclear neutrophils (PMNs) and ICAM-1 on melanoma cells initiate the bindings of melanoma cells to PMNs within the tumor microenvironment in blood flow, which in turn activate PMN-melanoma cell aggregation in a near-wall region of the vascular endothelium, therefore enhancing subsequent extravasation of melanoma cells in the microcirculations. Kinetics of integrin-ligand bindings in a shear flow is the determinant of such a process, which has not been well understood. In the present study, interactions of PMNs with WM9 melanoma cells were investigated to quantify the kinetics of [[beta].sub.2]-integrin and ICAM-1 bindings using a cone-plate viscometer that generates a linear shear flow combined with a two-color flow cytometry technique. Aggregation fractions exhibited a transition phase where it first increased before 60 s and then decreased with shear durations. Melanoma-PMN aggregation was also found to be inversely correlated with the shear rate. A previously developed probabilistic model was modified to predict the time dependence of aggregation fractions at different shear rates and medium viscosities. Kinetic parameters of [[beta].sub.2]-integrin and ICAM-1 bindings were obtained by individual or global fittings, which were comparable to respectively published values. These findings provide new quantitative understanding of the biophysical basis of leukocyte-tumor cell interactions mediated by specific receptor-ligand interactions under shear flow conditions. heterotypic cell aggregation; adhesion molecule; leukocyte; tumor cell; reverse rate; binding affinity; probabilistic model; polymorpho-nuclear neutrophils; intercellular adhesion molecule-1

Cytotoxic T lymphocytes (CTL) play an important role in the control and elimination of infection by West Nile virus (WNV), yet the class I human leukocyte antigen (HLA)-presented peptide epitopes that enable CTL recognition of WNV-infected cells remain uncharacterized. The goals of this work were first to discover the peptide epitopes that distinguish the class I HLA of WNV-infected cells and then to test the T cell reactivity of newly discovered WNV epitopes. To discover WNV-immune epitopes, class I HLA was harvested from WNV (NY99 strain)-infected and uninfected HeLa cells. Then peptide epitopes were eluted from affinity-purified HLA, and peptide epitopes from infected and uninfected cells were comparatively mapped by mass spectroscopy. Six virus-derived peptides from five different viral proteins (E, NS2b, NS3, NS4b, and NS5) were discovered as unique to HLA-A*0201 of infected cells, demonstrating that the peptides sampled by class I HLA are distributed widely throughout the WNV proteome. When tested with CTL from infected individuals, one dominant WNV target was apparent, two epitopes were subdominant, and three demonstrated little CTL reactivity. Finally, a sequence comparison of these epitopes with the hundreds of viral isolates shows that HLA-A*0201 presents epitopes derived from conserved regions of the virus. Detection and recovery from WNV infection are therefore functions of the ability of class I HLA molecules to reveal conserved WNV epitopes to an intact cellular immune system that subsequently recognizes infected cells. epitope hierarchy | human leukocyte antigen | immunodominance | major histocompatibility complex | mass spectrometry

Large proton fluxes accompany cell migration, but their precise role remains unclear. We studied pH regulation during the course of chemokinesis and chemotaxis in human neutrophils stimulated by attractant peptides. Activation of cell motility by chemoattractants was accompanied by a marked increase in metabolic acid generation, attributable to energy consumption by the contractile machinery and to stimulation of the NADPH oxidase and the ancillary hexose monophosphate shunt. Despite the increase in acid production, the cytosol underwent a sizable alkalinization, caused by acceleration of [Na.sup.+]/[H.sup.+] exchange. The development of the alkalinization mirrored the increase in the rate of cell migration, suggesting a causal relationship. However, elimination of [Na.sup.+]/[H.sup.+] exchange by omission of external [Na.sup.+] or by addition of potent inhibitors was without effect on either chemokinesis or chemotaxis, provided the cytosolic pH remained near neutrality. At more acidic levels, cell motility was progressively inhibited. These observations suggest that [Na.sup.+]/[H.sup.+] exchange plays a permissive role in cell motility but is not required for the initiation or development of the migratory response. Chemokinesis also was found to be exquisitely sensitive to extracellular acidification. This property may account for the inability of neutrophils to access abscesses and solid tumors that have been reported to have inordinately low pH. proton transport; cell motility; cytoskeleton; leukocyte

Both leukocytes and platelets accumulate in the colonic microvasculature during experimental colitis, leading to microvascular dysfunction and tissue injury. The objective of this study was to determine whether the recruitment of leukocytes and platelets in inflamed colonic venules are codependent processes. The rolling and adherence of leukocytes and platelets in colonic venules of mice with dextran sodium sulfate (DSS)-induced colitis were monitored by intravital videomicroscopy. DSS elicited an increased recruitment of both rolling and adherent leukocytes and platelets. DSS-colitic mice rendered thrombocytopenic with anti-platelet serum exhibited profound reductions in leukocyte adhesion. Neutropenia, induced with antineutrophil serum, significantly reduced the adhesion of leukocytes and the accumulation of platelet-leukocyte aggregates while greatly enhancing the number of platelets that roll and adhere directly to venular endothelial cells. The enhanced platelet adhesion associated with neutropenia was mediated by platelet P-selectin interactions with endothelial cell P-selectin glycoprotein ligand (PSGL-1). DSS colitis was also associated with an increased expression of PSGL-1 in the colonic vasculature. These findings indicate that the recruitment of leukocytes and platelets in inflamed colonic venules are codependent processes. platelets; leukocytes; intravital microscopy; P-selectin; P-selectin glycoprotein ligand-1

Modulation of adhesion molecule expression or function is regarded as a promising therapy for inflammatory conditions. This study evaluates the effects of an inhibitor of adhesion molecule expression (GI270384X) in two experimental models of colitis. Colitis of different severity was induced in C57BL/6J mice by administering 1, 2, or 3% dextran sulfate sodium (DSS). GI270384X (3, 10, or 25 mg x [kg.sup.-1] x [day.sup.-1]) was administered as pretreatment or started 3 days after colitis induction. In IL-10-deficient mice, the highest dose was given for 2 wk. The clinical course of colitis, pathological changes, serum inflammatory biomarkers, expression of adhesion molecules, and leukocyteendothelial cell interactions in colonic venules were measured in mice treated with vehicle or with active drug. In the most severe forms of colitis (2% and 3% DSS and IL-10-deficient mice), the magnitude of colonic inflammation was not modified by treatment with GI270384X. In a less severe form of colitis (1% DSS), GI270384X treatment dose dependently ameliorated the clinical signs of colitis, colonic pathological changes, and serum levels of biomarkers (IL-6 and serum amyloid A). Administration of 25 mg x [kg.sup.-1] x [day.sup.-1] GI270384X abrogated upregulation of ICAM-1 in the inflamed colon but had no effect on VCAM-1 or E-selectin expression. This was associated with a significant reduction in number of rolling and firmly adherent leukocytes in colonic venules. These results indicate that GI270384X is effective in the treatment of experimental colitis of moderate severity. Reduced adhesion molecule expression and leukocyte recruitment to the inflamed intestine contribute to this beneficial effect. endothelium; ICAM-1; leukocyte

Inflammation after renal ischemia-reperfusion (IR) injury is a major contributor to renal cell death. We previously demonstrated that several volatile anesthetics protect against renal IR injury and necrosis in rats in vivo. We subsequently showed that volatile anesthetics produced direct anti-inflammatory and anti-necrotic effects in cultured proximal tubule cells in vitro. In this study, we wanted to determine whether the volatile anesthetic isoflurane protects against renal IR injury by producing anti-inflammatory effects in mice. C57BL/6 mice subjected to renal IR under isoflurane anesthesia demonstrated improved renal function and reduced necrosis compared with mice subjected to renal IR under pentobarbital anesthesia. Mice subjected to renal IR under isoflurane anesthesia also showed a reduction in inflammation evidenced by a reduced renal influx of neutrophils and macrophages, reduced ICAM-1 expression, less upregulation of proinflammatory mRNAs (TNF-[alpha], ICAM-1, KC, and IL-1[beta]) as well as reduced nuclear translocation of NF-[kappa]B 24 h after renal IR injury. Analysis of specific lymphocyte subset trafficking to the kidney using flow cytometry demonstrated that isoflurane anesthesia reduced intrarenal influx of CD3+, CD4+, CD8+, and NK1.1+ lymphocytes at 3 h after renal ischemia compared with pentobarbital anesthesia. However, only the differential reduction of NK1.1+ lymphocytes persisted 24 h after renal ischemia. Therefore, we conclude that isoflurane anesthesia significantly attenuated renal IR injury in mice by reducing inflammation and modulating leukocyte influx. In particular, neutrophil, macrophage, and NK1.1 + lymphocyte cell modulation may play a significant role in renal protection by isoflurane anesthesia. acute renal failure; flow cytometry; immunohistochemistry; inflammation; volatile anesthetic

Vascular inflammation and enhanced production of angiotensin II (ANG II) are involved in the pathogenesis of hypertension and diabetes, disease states that predispose the afflicted individuals to ischemic disorders. In light of these observations, we postulated that ANG II may play a role in promoting leukocyte rolling (LR) and adhesion (LA) in postcapillary venules after exposure of the small intestine to ischemia-reperfusion (I/R). Using an intravital microscopic approach in C57BL/6J mice, we showed that ANG II type I (A[T.sub.1]) or type II (A[T.sub.2]) receptor antagonism (with valsartan or PD-123319, respectively), inhibition of angiotensin-converting enzyme (ACE) with captopril, or calcitonin generelated peptide (CGRP) receptor blockade (CGRP8-37) prevented postischemic LR but did not influence I/R-induced LA. However, both postischemic LR and LA were largely abolished by concomitant A[T.sub.1] and A[T.sub.2] receptor blockade or chymase inhibition (with Y-40079). Additionally, exogenously administered ANG II increased LR and LA, effects that were attenuated by pretreatment with a CGRP receptor antagonist or an NADPH oxidase inhibitor (apocynin). Our work suggests that ANG II, formed by the enzymatic activity of ACE and chymase, plays an important role in inducing postischemic LR and LA, effects that involve the engagement of both A[T.sub.1] and A[T.sub.2] receptors and may be mediated by CGRP and NADPH oxidase. ischemia; reperfusion; leukocyte rolling; leukocyte adhesion; angiotensin-converting enzyme; chymase; angiotensin A[T.sub.1] and A[T.sub.2] receptors; NADPH oxidase doi:10.1152/ajpheart.01210.2006.

Byline: Donald Kimpel (1), Tim Dayton (1), Krishnaswamy Kannan (1), Robert E. Wolf (1) Keywords: streptococcal cell wall arthritis; leukocytes; PG-PS; flowcytometry Abstract: Rheumatoid arthritis (RA) is a common systemic inflammatory disease thought to be T- helper-1 cell driven, though current controversy involves the relative role of T cells versus other leukocytes. Thus, there is a need for better understanding of the role of various leukocytes and their subsets in RA. Using the streptococcal cell wall (SCW) induced arthritis model, we examined leukocytes isolated from peripheral blood, spleen, and lymph nodes using monoclonal antibodies directed against lineage specific cell surface markers. Activation status of these cells was assessed using CD44 and CD71 as markers. T cells in general, and CD4.sup.+ T cells in particular were found to be activated in spleen and lymph nodes. B cells and monocytes in spleen demonstrated increased activation as well. The activation of cells in the myeloid and lymphoid lineages in the chronic phase of arthritis indicates ongoing involvement of innate and cognate immunity. This study quantitates specific changes in B and T lymphocytes, and myeloid cells and is consistent with findings in human RA in which specific antibodies, T cells, and myeloid cells are all implicated in the pathogenesis of RA. Author Affiliation: (1) Department of Medicine, Center of Excellence of Rheumatology and Arthritis, LSU Health Sciences Center, Shreveport, Louisiana Article History: Registration Date: 20/10/2004

Byline: R. Rotstein (1), M. Kassirer (1), D. Zeltser (1), N. Maharshak (1), T. Mardi (1), D. Avitzour (3), I. Shapira (1), D. Justo (1), N. Arber (2), S. Berliner (1) Abstract: Background: A simple capilary leukocyte adhesiveness/aggregation test (CAPLAAT) might be helpful in determining the intensity of inflammation in acute viral and bacterial infections. Patientsand Methods: We included 30 patients with acute bacterial infections, 14 with viral infectiona as well as 48 healthy controls. The leukocyte adhesiveness/aggregation test (LAAT) test was performed using a simple slide test and image analysis. Results: The CAPLAAT had a similar discrimination power between bacterial and viral infections as both the white blood cell count (WBC) and the erythrocyte sedimentation rate (ESR). It was more sensitive than the WBC and the ESR (77%, 68% and 66%, respectively) for the detection of bacterial infections and had a comparable negative predictive value. By analyzing the size distribution of the aggregated leukocytes, we found that a venous leukocyte adhesiveness/aggregation test (VLAAT) of four cells and more had the best positive predictive value (94%) and specificity (95%) for diagnosis of an acute bacterial infection (from all the acute phase response variables examined). Conclusion: The CAPLAAT might be attractive for the detection of inflammation and for the assessment of its severity at points of care where the services of a clinical laboratory are not available around the clock. Author Affiliation: (1) Dept. of Internal Medicine 'D', Tel Aviv, Sourasky Medical Center, 6 Weizman Str., 64239 Tel Aviv, Israel. shapiraiz@tasmc.health.gov.il, IL (2) Dept. of Gastroenterology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel, IL (3) Timorim Technologies, Jerusalem, Israel, IL Article note: Received: December 8, 2001 * Revision accepted: July 1, 2002 S. Berliner (corresponding author)

Byline: Helena Yusuf-Makagiansar (1), Irwan T. Makagiansar (1), Teruna J. Siahaan (1) Keywords: leukocyte infiltration; T-lymphocytes; adhesion molecules; apoptosis; LFA-1-peptide Abstract: Tissue inflammation is characterized by aggravated leukocyte infiltration into the sites of inflammation. The mechanism requires the interactions of leukocyte adhesion-molecules and their ligands in the inflamed tissues. In this study, we demonstrate that a cyclic peptide cLAB.L [cyclo1, 12-PenITDGEATDSGC], derived from the 'inserted' or I-domain of LFA-1 is able to inhibit the adherence of T-lymphocytes to the epithelial cell monolayers. This inhibition has been thought to involve the disruption of LFA-1/ICAM-1 interaction. The heterotypic adhesion of phorbol ester-activated Molt-3 cells and IFN-I3-induced Caco-2 monolayers was inhibited upon treatment of the monolayers with monoclonal antibodies (MAbs) to adhesion molecules or with cLAB.L peptide. The adhesion can be inhibited by MAbs to ICAM-1, ICAM-2, and VCAM-1, and cLAB.L peptide in a concentration-dependent manner. However, none of the individual uses of these molecules led to a total inhibition. The inhibitory activity of cLAB.L is greatly reduced by low temperature and the absence of cell activation. Treatment of cLAB.L peptide may trigger an early event of apoptosis on activated but not on non-activated Molt-3 cells no indication of peptide-induced apoptosis was found on Caco-2 cells. Taken together, data from this work suggest that cLAB.L may have applications to direct cell-targeted delivery during tissue inflammation. Author Affiliation: (1) Department of Pharmaceutical Chemistry, Simons Research Laboratories, The University of Kansas, 2095 Constant Avenue, Lawrence, Kansas, 66047 Article History: Registration Date: 17/10/2004

Byline: Trent M. Woodruff (1), Anna J. Strachan (1), Sam D. Sanderson (2), Peter N. Monk (3), Allan K. Wong (4), David P. Fairlie (4), Stephen M. Taylor (1) Keywords: C5a antagonist; C5a agonist; leukocytes Abstract: This study investigated the receptor binding affinities of a C5a agonist and cyclic antagonists for polymorphonuclear leukocytes (PMNs) isolated from human, sheep, pig, dog, rabbit, guinea pig, rat and mouse. The affinities of the two small molecule antagonists, F-[OPdChaWR] and AcF-[OPdChaWR], and the agonist, YSFKPMPLaR, revealed large differences in C5a receptor (C5aR) affinities between species. The antagonists bound to human, rat and dog PMNs with similar high affinities, but with lower affinities to PMNs from all other species. The C5a agonist also bound with varying affinities between species, but showed a different affinity profile to the antagonists. In contrast, recombinant human C5a had similar affinity for PMNs of all species investigated. The low correlation between the affinities of the antagonists and the agonist between species either suggests that different receptor residues are important for distinguishing between agonist/antagonist binding, or that the agonist and antagonist peptides bind to two distinct sites within the C5aR. Author Affiliation: (1) Department of Physiology and Pharmacology, Australia (2) Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha (3) Department of Molecular Biology and Biotechnology, University of Sheffield, United Kingdom (4) Centre for Drug Design and Development, University of Queensland, Australia Article History: Registration Date: 17/10/2004

Byline: M. Kassirer (1), D. Zeltser (1), N. Maharshak (1), R. Rotstein (1), O. Rogowsky (1), I. Shapira (1), N. Arber (2), A.S. Berliner (1) Keywords: Key Words Leukocyte adhesiveness; Viral versus nonviral infection Abstract: Background: Viral infection differs from nonviral infection/inflammation by not producing a significant acute phase response. Since inflammation can cause increased adhesiveness of peripheral white blood cells (WBC), we compared these adhesive properties in individuals with viral infection to those with nonviral infection/inflammation. Patients and Methods: The state of leukocyte adhesiveness/aggregation in the peripheral blood of patients with viral versus nonviral infection/inflammation was examined in 101 consecutive patients with acute febrile disease. Results: A significant difference was found between the two groups 13.6 +- 7% for viral infection versus 22.8 +- 8.5% for nonviral infection/inflammation (p &lt 0.0001). There was also a significant difference in the concentration of fibrinogen (361 +- 109 mg/dl vs 554 +- 172 mg/dl, p &lt 0.0001), and in the CD11b/CD18 cell surface expression (175 +- 66 vs 210 +- 100 in peripheral blood polymorphonuclear leukocytes). Conclusion: The results of this study could explain, at least in part, the differential adhesive behavior of the WBC in the peripheral blood in the two populations. Author Affiliation: (1) Dept. of Internal Medicine 'D', Tel-Aviv Sourasky Medical Center, 6 Weizmann Street, Tel Aviv 64239, Israel Phone: (+97/23) 697-3313, Fax: -4961, e-mail: dzeltser@netvision.net, IL (2) Dept. of Gastroenterology, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel, IL Article note: Received: October 10, 1999 * Revision accepted: December 19, 2000

Byline: Gerd Egger (1), Astrid Burda (1), Andrea Obernosterer (2), Heike Mitterhammer (2), Gerd Kager (3), Gunther Jurgens (3), Herwig Peter Hofer (4), Judith S. Fabjan (5), Ernst Pilger (2) Keywords: atherosclerosis, inflammation, PMN, migration, aspirin Abstract: The aim of the study was to demonstrate an activation of polymorpho-nuclear leukocytes (PMNs) in chronic progressive atherosclerosis (ATH). A group of patients with ATH, and a group of ATH patients under aspirin (ASA) therapy were compared with control persons without atherosclerotic alterations (healthy controls). Each group comprised 15 male age-matched subjects. The following inflammatory parameters related to PMN activities were measured: the polymorphonuclear leukocyte (PMN) blood count blood PMN migration and reactive oxygen species release in vitro the blood levels of PMN elastase, malondialdehyde, antibodies to oxidized LDL and soluble ICAM-1. In ATH patients, the PMN blood counts and the share of blood PMNs migrating upon platelet activating factor and leukotriene B4 stimulation were significnatly above the values of the healthy controls, while the other parameters were not significantly altered. ASA treatment attenuated the inflammatory response and reduced the differences between ATH and the healthy controls. It can be concluded that, in patients with chronic progressive atherosclerosis, PMNs are involved in the inflammatory process underlying the disease. Author Affiliation: (1) Institute of Pathophysiology, Karl Franzens University, Graz, Austria (2) Department of Internal Medicine, Karl Franzens University, Graz, Austria (3) Institute of Medical Biochemistry, Karl Franzens University, Graz, Austria (4) Department of Traumatology, Karl Franzens University, Graz, Austria (5) Institute of Biochemistry, Karl Franzens University, Graz, Austria Article History: Registration Date: 17/10/2004

Byline: Kingsley Yin (1), Jeanette Wilmanski (1), Congli Wang (1), Gang Qiu (1), Maria Tahamont (2) Abstract: Lung injury commonly occurs in the setting of systemic inflammatory response syndrome occurring during bacterial sepsis. There has been little work quantifying different leukocytes within the different compartments of the lung and their association with overt lung injury in sepsis. We examined the pathogenesis of lung injury after cecal ligation and puncture (CLP), a clinically relevant model of sepsis. To assess the sequestration and migration of leukocytes, leukocyte differentials were obtained for the lung vascular compartment and the bronchoalveolar airspace. At 24 h post CLP, there were signs of edema in the lung, while at 48 h after CLP, there were clear indications of alveolar wall thickening with increased cellularity and diffuse alveolar hemorrhage. The number of lymphocytes in the pulmonary vascular compartment dropped by 50% and doubled in the (bronchoalveolar lavage) BAL, 24 h after CLP compared to sham controls suggesting that there was transendothelial migration of lymphocytes. At 48 h after CLP, lymphocyte numbers in the vasculature was similar to controls but BAL lymphocyte numbers were still raised. The number of pulmonary intravascular neutrophils were similar to controls at 24 h post CLP but were greatly elevated 48 h after CLP. The increase in neutrophils was partly due to a substantial increase in the percentage of immature band cells, indicating recruitment of neutrophils from the bone marrow. There were very few neutrophils in the BAL of sham controls and CLP rats. Perfusate monocyte/macrophages were significantly increased 48 h after CLP and a similar increase in macrophages was observed in the BAL. These results strongly suggest a role for lymphocytes and macrophages in the development of overt lung injury as the migration of these cells corresponds to that of the appearance of lung injury 48 h after CLP. Importantly our data also demonstrates the compartmentalization and migration of different inflammatory cell-types during the development of sepsis. Author Affiliation: (1) Department of Cell Biology, University of Medicine and Dentistry, School of Osteopathic Medicine, Stratford, New Jersey, 08084 (2) Department of Biology, Rowan University, Glassboro, New Jersey, 08028 Article History: Registration Date: 05/10/2004

Byline: Els M. E. Verdegaal (1,2), Suzanne T. Zegveld (1), Irene Blokland (1), Henry Beekhuizen (1), Wim Bakker (3), Luuk N. A. Willems (3), Ralph Van Furth (1) Abstract: Upregulation of adhesion molecule expression on endothelial cells (EC) and circulating leukocytes, by locally produced inflammatory mediators, may result in the enhanced infiltration of leukocytes into tissue, e.g. the airways of asthma patients. The present study investigates whether the expression of adhesion molecules on granulocytes and monocytes from asthma patients is affected by chemotactic factors, i.e. interleukin-8 (IL-8) and monocyte chemotactic protein-1 (MCP-1). Flow cytometric analysis showed that the intrinsic expression of the various adhesion molecules on peripheral blood phagocytes from asthma patients was not different from that of healthy individuals. However, stimulation of monocytes with MCP-1 resulted only in upregulation of the expression of CD14 on monocytes from symptomatic asthma patients but not on monocytes from asymptomatic asthma patients and healthy individuals. Stimulation of granulocytes with IL-8 did not change the expression of the various [beta].sub.1-and [beta].sub.2-integrin molecules, such as VLA-4, LFA-1, CR3 and p150,95. Since earlier studies have shown that CD14 on monocytes mediates monocyte adhesion to activated vascular EC the present findings suggest that during the active phase of asthma upregulation of CD14 on monocytes by MCP-1 may lead to an increased adhesion of monocytes to vascular endothelium and their subsequent transendothelial migration into the tissue of the airways. Author Affiliation: (1) Department of Infectious Diseases, University Hospital, Leiden. (2) Department of Clinical Oncology, University Hospital, Leiden., The Netherlands. (3) Department of Pulmonary Diseases, Leyenburg Hospital, Den Haag Article History: Registration Date: 03/10/2004

A group of specialized white blood cells migrates back and forth through lymph nodes to teach other immune cells how to make a greater variety of antibodies against invading bacteria [...]

Rather than just providing an unstructured adhesive surface for leukocytes, cytokine-activated endothelial cells assemble preexisting tetraspanin-enriched microdomains to form endothelial adhesive platforms (EAPs) and endothelial docking structures. In this issue of the Journal of Cell Biology, Barreiro et al. (Barreiro, O., M. Zamai, M. Yaez-Mo, E. Tejera, P. Lopez-Romero, P.N. Monk, E. Gratton, V.R. Caiolfa, and F. Sanchez-Madrid. 2008. J. Cell Biol. 183:527-542) show how the immunoglobulin superfamily adhesion molecules intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 form nanoclusters with the tetraspanins CD9 and CD151 in a physiologically relevant system. Furthermore, convincing biochemical data suggest that these structures are distinct from lipid rafts.

In obese individuals, fat cells may act like inflammatory white blood cells by using communication machinery once considered to be exclusive to immune cells. High numbers of several types of [...]

A subset of white blood cells may determine who is best protected by seasonal flu vaccines. Hideki Ueno at Baylor Research Institute in Dallas, Texas, and Octavio Ramilo at the [...]