AIMTo investigate the mechanism of the vascular endothelial cell (VEC) injury caused by freezing/thawing.

METHODSThe frozen/thawed neutrophil (PMN) model was founded by freezing PMNs with a rate cooling instrument and then rewarming them in a water bath, the PMNs used here were separated from rat's peripheral blood using density gradients centrifugation techniques. The expression of LFA-1 on the surface of frozen/thawed PMNs was observed at 4 h,12 h and 24 h after freezing/thawing. After co-incubating untreated VECs with frozen/thawed PMNs, we detected the VEC injury and the changes in PMN-VEC adhesion.

RESULTS(1) The PMNs LFA-1 expression increased in a time-dependent manner within 24 h after the freezing/thawing of PMNs. (2) After co-incubating untreated VECs with frozen/thawed PMNs, the adhesion between frozen/thawed PMNs and VECs increased and VEC injury occurred. (3) Monoclonal antibody against LFA-1 could block the PMN-VEC adhesion and subsequently attenuated the VEC injury.

CONCLUSIONThe freezing/thawing of PMNs can elicited an increase in PMN LFA-1 expression and trigger the PMN-VEC adhesion and subsequently bring about the VEC injury.

Animals ; Cells, Cultured ; Endothelial Cells ; cytology ; Freezing ; Lymphocyte Function-Associated Antigen-1 ; metabolism ; Neutrophils ; cytology ; metabolism ; Rats ; Rats, Wistar

LFA-1 and ICAM-1 mediate a bi-directional signaling across the cell membrane which is essential for biological functions of lymphocyte, including exudation, activation, adhesion, immunosurveillance as well as immuno-logical synapse formation. The signal transducing is a dynamic process and dependent on the binding capacity between LFA-1 and ICAM-1. The affinity and the avidity of LFA-1 are two major regulation forms in this process. Phosphorylation of LFA-1 and cytoskeleton protein talin 1 play a critical role in signal transducing. In biology of lymphocyte, LFA-1 and ICAM-1 interaction forms the co-stimulatory signal to promote activation, proliferation and division. In this article the regulation of binding capacity between LFA-1 and ICAM-1, the regulation of LFA-1 subunit phosphorylation, the role of talin1 in signaling transduction of LFA-1 and ICAM-1, the synergic stimulatory signaling of LPA-1 and ICAM-1 were reviewed.
Humans ; Intercellular Adhesion Molecule-1 ; metabolism ; physiology ; Ligands ; Lymphocyte Function-Associated Antigen-1 ; metabolism ; physiology ; Lymphocytes ; cytology ; immunology ; metabolism ; Phosphorylation ; Signal Transduction ; physiology ; Talin ; metabolism

The basic route and mechanism for diapedesis has not yet to be fully defined. Here we present evidence that "cell-cell separation" between endothelial cells (ECs) may provide a route for leukocyte diapedesis. We unexpectedly found that extensive interaction between peripheral blood leukocytes and ECs that were activated by TNF-alpha induced the opening of EC contacts and, surprisingly, resulted in cell-cell separation. This event was specific to the intercellular adhesion molecules-1 (ICAM-1)/leukocyte function-associated antigen-1 interaction, as demonstrated by the following: (1) ICAM-1 expression correlated with increased EC contraction; and (2) the blocking of ICAM-1 selectively inhibited EC separation. Thus, we suggest that "cell-cell separation" could be a mechanism for diapedesis in situations that may require massive leukocyte infiltration.
Cell Movement ; Cells, Cultured ; Endothelial Cells/*cytology/metabolism ; Flow Cytometry ; Fluorescent Antibody Technique ; Humans ; Intercellular Adhesion Molecule-1/*metabolism ; Leukocytes/cytology/*immunology ; Lymphocyte Function-Associated Antigen-1/*metabolism

The basic route and mechanism for diapedesis has not yet to be fully defined. Here we present evidence that "cell-cell separation" between endothelial cells (ECs) may provide a route for leukocyte diapedesis. We unexpectedly found that extensive interaction between peripheral blood leukocytes and ECs that were activated by TNF-alpha induced the opening of EC contacts and, surprisingly, resulted in cell-cell separation. This event was specific to the intercellular adhesion molecules-1 (ICAM-1)/leukocyte function-associated antigen-1 interaction, as demonstrated by the following: (1) ICAM-1 expression correlated with increased EC contraction; and (2) the blocking of ICAM-1 selectively inhibited EC separation. Thus, we suggest that "cell-cell separation" could be a mechanism for diapedesis in situations that may require massive leukocyte infiltration.
Cell Movement ; Cells, Cultured ; Endothelial Cells/*cytology/metabolism ; Flow Cytometry ; Fluorescent Antibody Technique ; Humans ; Intercellular Adhesion Molecule-1/*metabolism ; Leukocytes/cytology/*immunology ; Lymphocyte Function-Associated Antigen-1/*metabolism

Child ; Child, Preschool ; Female ; Humans ; Infant ; Intercellular Adhesion Molecule-1 ; blood ; Leukocytes, Mononuclear ; metabolism ; Lymphocyte Function-Associated Antigen-1 ; blood ; Male ; Seizures, Febrile ; blood

AIMTo investigate the role of TNF-alpha in vascular endothelial cells injury mediated by freezing/thaw ing PMN.

METHODSFreezing/thawing cell model was founded using rat PMN isolated by dextran sedimentation technique and VEC cultured in vitro. The injury level of VEC was indicated by measuring activity of LDH in medium. The number of frozen/thawed PMN adhering to VEC was counted with Phagocytizing reactive dyes the degree of frozen/thawed PMN and VEC adhesion. Expression of LFA-1 on the surface of frozen/thawed PMN was analyzed with flow cytometry.

RESULTSTNF-alpha could obviously upregulate expression of LFA-1 on surfaced of frozen/thawed PMN. Upregulation of LFA-1 expression promoted adhesion of frozen/thawed PMN and normal VEC,and aggravated VEC injury. Monoclonal antibody against LFA-1 could partly block adhesion of frozen/thawed PMN and normal VEC,and attenuate VEC injury.

CONCLUSIONTNF-alpha can promote expression of LFA-1 on surface of frozen/thawed PMN adhering of frozen/thawed PMN to normal VEC and VEC injury increase, monoclonal antibody against LFA-1 could partly block PMN-VEC adhesion and attenuate VEC injury.

Animals ; Cell Adhesion ; Cells, Cultured ; Endothelial Cells ; drug effects ; Endothelium, Vascular ; cytology ; Freezing ; Lymphocyte Function-Associated Antigen-1 ; metabolism ; Neutrophils ; cytology ; metabolism ; Rats ; Tumor Necrosis Factor-alpha ; pharmacology

OBJECTIVETo explore the impact of mobilization with recombinant human granulocyte colony stimulated factor (rhG-CSF) on the migration and adhesive function and their related signal mechanism mediated by the CXCR4 and lymphocyte function antigen-1 (LFA-1) molecules on the surfaces of CD4(+) T cells.

METHODSBefore and at day 5 on rhG-CSF mobilization, the expression rates of CXCR4 and LFA-1 (CD11a) on CD4(+) T cells in the peripheral blood were detected by tricolor fluorescence labeling, and the migration and adhesive activities of CD4(+) T cells to stroma cell-derived factor 1 alpha (SDF-1 alpha) and intercellular adhesion molecule-1 (ICAM-1) were also tested.

RESULTSThe expression of CXCR4 on CD4(+) T lymphocytes was (84.58 +/- 20.31)% before mobilization and (81.23 +/- 22.46)% at day 5 on mobilization. The expression of LFA-1 on CD4(+) T lymphocytes before and at day 5 on mobilization was 100%. There was no significant difference in the expression CXCR-4 and LFA-1 on CD4(+) T lymphocytes whether mobilization (P > 0.05). SDF-1 alpha induced 4 hours' CD4(+) T cells migration didn't change markedly before and after mobilization \[(28.5 +/- 10.3)% vs (31.2 +/- 8.9)%\] (P > 0.05). The adhesive activity of CD4(+) T cells to ICAM-1 was decreased from (85.59 +/- 14.21)% to (61.45 +/- 15.07)% after mobilization (P < 0.05).

CONCLUSIONSThe expression of CXCR4 and LFA-1 on CD4(+) T lymphocytes didn't change markedly during rhG-CSF mobilization, but the adhesive activity of CD4(+) T cells to ICAM-1 was frustrated after that.

CD4-Positive T-Lymphocytes ; drug effects ; immunology ; metabolism ; physiology ; Cell Adhesion ; Cell Movement ; Cells, Cultured ; Chemokine CXCL12 ; physiology ; Granulocyte Colony-Stimulating Factor ; pharmacology ; Humans ; Intercellular Adhesion Molecule-1 ; physiology ; Lymphocyte Function-Associated Antigen-1 ; metabolism ; Receptors, CXCR4 ; metabolism ; Recombinant Proteins

The effects of ligustrazine on the expression of LFA-1, ICAM-1 in bone marrow tissue and the mechanism promoting hematopoietic reconstitution following bone marrow transplantation (BMT) were investigated. The 150 mice were randomly divided into 3 groups: normal group, saline group and ligustrazine group. The normal group received no treatment, while in the saline group and ligustrazine group, the mice were subjected to normal saline (0.2 ml, twice a day) and ligustrazine (0.2 ml, twice a day) respectively through a gastric tube. At the 7th, 14th, 21st and 28th day after BMT, survival rate, colony forming unit of spleen (CFU-S), peripheral blood cells and bone marrow mononuclear cells (BMMNC) were measured, histological changes in bone marrow tissue were observed and the expression level of LFA-1, ICAM-1 was detected. In ligustrazine group CFU-S counts on the 10th day and the peripheral blood WBC, PLT, BMMNC counts, hematopoietic tissue volume as well as the expression level of LFA-1 on the 7th, 14th, 21st, 28th day after BMT were higher than in saline group (P<0.01 or P<0.05). Mature RBC volume and the expression level of ICAM-1 were significantly lower in the ligustrazine group than in the saline group (P<0.01 or P<0.05). In the ligustrazine group, fat tissue volume was higher on the 7th, 14th day after BMT (P<0.01) and was lower on the 21st, 28th day (P<0.01) after BMT than in the saline group. It was concluded that Ligustrazine could improve bone marrow microenvironment and promote hematopoietic reconstitution.
Animals ; Bone Marrow Transplantation ; Female ; Hematopoiesis ; drug effects ; Hematopoietic Stem Cells ; drug effects ; metabolism ; Intercellular Adhesion Molecule-1 ; biosynthesis ; genetics ; Lymphocyte Function-Associated Antigen-1 ; biosynthesis ; genetics ; Male ; Mice ; Mice, Inbred BALB C ; Pyrazines ; pharmacology ; Random Allocation

OBJECTIVETo investigate the influence of glucocorticoid on phenotype of thymic dendritic cells in mice and to investigate the protective effect of Yougui Pill (YGP) on it.

METHODSBALB/c mice allocated in the group A and B were treated respectively with 10 mg/kg hydrocortisone, alone and combined with 20.81 g/kg YGP. The control mice were treated with normal saline. The changes before and after treatment of I-A(d) and H-2K(d) antigen presentation molecules expression in CD11c(+) and CD45(+) thymic dendritic cells of mice were analyzed by flow cytometry assay, and the expression of intercellular adhesion molecule-1 (ICAM-1) and leukocyte function-associated antigen-1 (LFA-1) mRNA in thymocytes were determined by RT-PCR as well.

RESULTSThe percentage of I-A(d+) and H-2K(d+) in CD11c(+) in Group A after treatment was 46.77 +/- 4.32% and 64.34 +/- 7.69% respectively, as compared with those in the control group (65.81 +/- 7.69% and 31.88 +/- 5.01%), the percentage of I-A(d+) was lower and that of H-2K(d+) was higher significantly (all P <0.01). Meantime, the expression of ICAM-1 and LFA-1 in thymocyte in Group A (30.11 +/- 2.51% and 30.40 +/- 3.77%) was significantly lower than that in the control group (46.35 +/- 3.34% and 47.28 +/- 2.91%) respectively (P <0.01). Changes in Group B showed that treated by hydrocortisone in combination with YGP, the above-mentioned hydrocortisone-induced changes could be obviously reversed, the outcome of CD11c(+) I-A(d+) was 54.19 +/- 5.08%, ICAM-1 33.97 +/- 2.04% and LFA-1 34.80 +/- 2.92%, the difference between the two treated groups in these indexes all showed statistical significance (P <0.05).

CONCLUSIONGlucocorticoidcan inhibit the expression of major histocompatibility complex class II antigen molecule, but promote the expression of major histocompatibility complex class I in CD11c(+) and CD45(+) dendritic cells, down-regulate ICAM-1 and LFA-1 transcription, while the tonifying yang recipe, YGP, has a dominant protective effect against the above actions of glucocorticoid.

Animals ; CD11c Antigen ; metabolism ; Dendritic Cells ; cytology ; drug effects ; immunology ; Drugs, Chinese Herbal ; pharmacology ; H-2 Antigens ; metabolism ; Histocompatibility Antigens Class II ; metabolism ; Hydrocortisone ; toxicity ; Intercellular Adhesion Molecule-1 ; metabolism ; Leukocyte Common Antigens ; metabolism ; Lymphocyte Function-Associated Antigen-1 ; metabolism ; Mice ; Mice, Inbred BALB C ; Phenotype ; Protective Agents ; pharmacology ; Thymus Gland ; cytology ; drug effects ; immunology

To investigate whether lymphocyte function-associated antigen 1 (LFA-1) and very late antigen 4 (VLA-4) are involved in vasoendothelial adhesion and transendothelial migration of high proliferative potential endothelial progenitor cells (HPP-EPCs), flow cytometry was used to analyze the expression of integrin beta1 and beta2, the expression of intercellular adhesion molecule (ICAM-1, 2) and vascular cell adhesion molecule (VCAM-1) in mouse bone marrow endothelial cells (mBMECs). The adhesion and transmigration through endothelial cells of the HPP-EPCs blocked by functional grade neutralizing antibodies of VLA-4 and LFA-1 were studied in vitro. The results revealed that HPP-EPCs were positive for CD11a and CD49d in HPP-EPCs. The expression of ICAM-1and VCAM-1 of mBMECs increased after activated by IL-1beta and TNF-alpha. The results of adhesion in vitro revealed that the numbers of the adhered and migrated cells in the CD11a antibody group, in the CD49d antibody group and in the combinational antibody group were less than those in the isotype control antibody group. Furthermore, the number of adhered and migrated cells in the combinational antibody group was less than that in the CD11a or the CD49d antibody group (p < 0.05). It is concluded that both LFA-1 and VLA-4 are involved in vasoendothelial adhesion and transendothelial migration of HPP-EPCs.
Animals ; Antigens, CD ; metabolism ; Bone Marrow Cells ; cytology ; Cell Adhesion ; Cell Adhesion Molecules ; metabolism ; Cell Movement ; Cells, Cultured ; Endothelial Cells ; cytology ; Humans ; Integrin alpha4beta1 ; physiology ; Intercellular Adhesion Molecule-1 ; metabolism ; Lymphocyte Function-Associated Antigen-1 ; physiology ; Mice ; Stem Cells ; cytology ; Vascular Cell Adhesion Molecule-1 ; metabolism