Prostaglandin E
              2
              and monoclonal antibody to lymphocyte function‐associated antigen‐1 differentially inhibit migration of T lymphocytes across microvascular retinal endothelial cells in rat

ABSTRACTKlebsiella pneumoniaehas become an important pathogen in recent years. Although most cases ofK. pneumoniaeendogenous endophthalmitis occur via hematogenous spread, it is not yet clear which microbial and host factors are responsible for the ability ofK. pneumoniaeto cross the blood-retinal barrier (BRB). In the present study, we show that in anin vitromodel of BRB based on coculturing primary bovine retinal endothelial cells (BREC) and primary bovine retinal pericytes (BRPC),K. pneumoniaeinfection determines changes of transendothelial electrical resistance (TEER) and permeability to sodium fluorescein. In the coculture model, bacteria are able to stimulate the enzyme activities of endothelial cytosolic and Ca2+-independent phospholipase A2s (cPLA2and iPLA2). These results were confirmed by the incremental expression of cPLA2, iPLA2, cyclo-oxygenase-1 (COX1), and COX2 in BREC, as well as by cPLA2phosphorylation. In supernatants ofK. pneumoniae-stimulated cocultures, increases in prostaglandin E2(PGE2), interleukin-6 (IL-6), IL-8, and vascular endothelial growth factor (VEGF) production were found. Incubation withK. pneumoniaein the presence of arachidonoyl trifluoromethyl ketone (AACOCF3) or bromoenol lactone (BEL) caused decreased PGE2and VEGF release. Scanning electron microscopy and transmission electron microscopy images of BREC and BRPC showed adhesion ofK. pneumoniaeto the cells, but no invasion occurred.K. pneumoniaeinfection also produced reductions in pericyte numbers; transfection of BREC cocultured with BRPC and of human retinal endothelial cells (HREC) cocultured with human retinal pericytes (HRPC) with small interfering RNAs (siRNAs) targeted to cPLA2and iPLA2restored the pericyte numbers and the TEER and permeability values. Our results show the proinflammatory effect ofK. pneumoniaeon BREC, suggest a possible mechanism by which BREC and BRPC react to theK. pneumoniaeinfection, and may provide physicians and patients with new ways of fighting blinding diseases.

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Lymphocyte function-associated antigens one (LFA-1) on B and on T lymphocytes bind a monoclonal antibody with different affinities

Cellular Immunology ◽

10.1016/0008-8749(85)90048-6 ◽

1985 ◽

Vol 91 (1) ◽

pp. 255-262 ◽

Cited By ~ 8

Author(s):

AndréJ. van Agthoven ◽

Alemseged Truneh

Keyword(s):

Monoclonal Antibody ◽

T Lymphocytes ◽

Lymphocyte Function

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A talin-dependent LFA-1 focal zone is formed by rapidly migrating T lymphocytes

The Journal of Cell Biology ◽

10.1083/jcb.200412032 ◽

2005 ◽

Vol 170 (1) ◽

pp. 141-151 ◽

Cited By ~ 141

Author(s):

Andrew Smith ◽

Yolanda R. Carrasco ◽

Paula Stanley ◽

Nelly Kieffer ◽

Facundo D. Batista ◽

...

Keyword(s):

Endothelial Cells ◽

T Lymphocytes ◽

Focal Adhesions ◽

Cell Types ◽

Intercellular Adhesion Molecule ◽

Lymphocyte Function ◽

Intercellular Adhesion Molecule 1 ◽

The Stability ◽

Focal Zone ◽

Cell Zone

Cells such as fibroblasts and endothelial cells migrate through the coordinated responses of discrete integrin-containing focal adhesions and complexes. In contrast, little is known about the organization of integrins on the highly motile T lymphocyte. We have investigated the distribution, activity, and cytoskeletal linkage of the integrin lymphocyte function associated antigen-1 (LFA-1) on human T lymphocytes migrating on endothelial cells and on ligand intercellular adhesion molecule-1 (ICAM-1). The pattern of total LFA-1 varies from low expression in the lamellipodia to high expression in the uropod. However, high affinity, clustered LFA-1 is restricted to a mid-cell zone that remains stable over time and over a range of ICAM-1 densities. Talin is essential for the stability and formation of the LFA-1 zone. Disruption of the talin–integrin link leads to loss of zone integrity and a substantial decrease in speed of migration on ICAM-1. This adhesive structure, which differs from the previously described integrin-containing attachments displayed by many other cell types, we have termed the “focal zone.”

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Glycerol-3-phosphate acyltransferase-1 regulates murine T-lymphocyte proliferation and cytokine production

AJP Cell Physiology ◽

10.1152/ajpcell.00371.2007 ◽

2008 ◽

Vol 295 (6) ◽

pp. C1543-C1549 ◽

Cited By ~ 18

Author(s):

Lauren W. Collison ◽

Eric J. Murphy ◽

Christopher A. Jolly

Keyword(s):

T Lymphocytes ◽

T Lymphocyte ◽

Lymphocyte Proliferation ◽

Membrane Lipid ◽

Cytokine Secretion ◽

Prostaglandin E ◽

Lymphocyte Function ◽

T Lymphocyte Proliferation ◽

Induced Apoptosis

We have previously established a correlation between reduced mitochondrial glycerol-3-phosphate acyltransferase-1 (GPAT-1) activity and decreased proliferation in splenic T-lymphocytes from aged rats. To better understand the immunoregulatory role of GPAT-1, we examined T-lymphocyte function in young GPAT-1 knockout (KO) mice. We show that without GPAT-1, T-lymphocyte proliferation is inhibited and activation induced apoptosis is increased. Th-1 (IL-2 and IFN-γ) cytokine secretion is reduced, and Th-2 (IL-4 and IL-10) cytokine secretion is increased. These changes may be due to alterations in membrane lipid composition since we found changes in the relative content of individual phospholipid species. Furthermore, we show increased arachidonate content and subsequent increased prostaglandin E2 secretion, which may inhibit T-lymphocyte proliferation. Taken together, we show a novel link between GPAT-1 and changes in T-lymphocyte function. These data have broad health implications because GPAT-1 suppression has recently been implicated as a new target for preventing insulin sensitivity and hepatic steatosis and we show that immune function may also be affected. Interestingly, the changes in young GPAT-1 KO splenic T-lymphocytes are similar to defects commonly seen in T-lymphocytes from aged rodents, which further underscores the significance of GPAT-1 in T-lymphocyte function.

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Prevention of vasospasm by anti-CD11/CD18 monoclonal antibody therapy following subarachnoid hemorrhage in rabbits

Journal of Neurosurgery ◽

10.3171/jns.2004.101.1.0088 ◽

2004 ◽

Vol 101 (1) ◽

pp. 88-92 ◽

Cited By ~ 48

Author(s):

Gustavo Pradilla ◽

Paul P. Wang ◽

Federico G. Legnani ◽

Lynn Ogata ◽

Gregory N. Dietsch ◽

...

Keyword(s):

Monoclonal Antibody ◽

Endothelial Cells ◽

Subarachnoid Hemorrhage ◽

Autologous Blood ◽

Rabbit Model ◽

Control Group ◽

Lymphocyte Function ◽

Content Type ◽

Basilar Arteries ◽

Fine Print

Object. Adhesion of leukocytes and their migration into the periadventitial space may be critical in the pathophysiology of vasospasm following subarachnoid hemorrhage (SAH). The cell adhesion molecules involved in this process are lymphocyte function—associated antigen—1 (CD11a/CD18) and macrophage antigen—1 (CD11b/CD18), which are present on neutrophils/macrophages, and intercellular adhesion molecule—1 (CD54), which is present in endothelial cells. A humanized monoclonal antibody (mAb), Hu23F2G, targets CD11/CD18 and prevents leukocyte adhesion to endothelial cells. In this study, systemic administration of Hu23F2G prevented vasospasm in the rabbit model of SAH. Methods. Twenty-six New Zealand White rabbits were injected with autologous blood into the cisterna magna to induce SAH, after which they were randomized to receive injections of either Hu23F2G (10 animals) or a placebo at 30 minutes and 24 and 48 hours after SAH (six animals). Control animals underwent sham operations (four animals) or SAH alone (six animals). The animals were killed 72 hours after SAH, their bodies perfused and fixed, and their basilar arteries processed for morphometric analysis. Peripheral white blood cells (WBCs) were counted at 72 hours. The percentages of lumen patency were compared using the Student t-test. The presence of neutrophils and macrophages was confirmed by immunohistochemical analysis in which a rat anti—rabbit anti-CD18 mAb and cresyl violet were used. Treatment with Hu23F2G resulted in the significant prevention of vasospasm. Animals treated with Hu23F2G had 90 ± 7% lumen patency compared with 65 ± 7% in the placebo group (p = 0.025). The percentage of lumen patency in the SAH-only group was 59 ± 10%. The mean WBC count was 16,300 ± 2710/µl in the treatment group, compared with 7000 ± 386/µl in the control group (p = 0.02). Administration of Hu23F2G produced increased numbers of WBCs in 70% of the animals treated. Conclusions. This study supports the concept that leukocyte—endothelial cell interactions play an important role in the pathophysiology of chronic vasospasm after SAH. Systemic therapy with an anti-CD11/CD18 mAb prevents vasospasm after SAH by inhibiting adhesion of neutrophils and macrophages and their migration into the periadventitial space.

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