BACKGROUND: Cell adhesion molecules (CAMs) expressed on hematopoietic progenitor cells (HPCs), endothelial cells, and stromal cells play a pivotal role in the mobilization of CD34+ cells. Herein, we conducted a non-randomized peripheral blood stem cell (PBSC) mobilization study aimed to compare the potential differences in the expressions of several CAMs and chemokines on CD34+ cells obtained from bone marrow aspirate before and after HPC mobilization from patients with hematologic malignancies and healthy donors. METHODS: Three-color cytofluorometric analysis was used to compare the expressions of CAMs and chemokines in the bone marrow before and after mobilization. RESULTS: For all studied groups, CAM expression among those with good and poor yields of CD34+ cells was significantly correlated with VCAM-1 (P=0.007), CD44 (P=0.027), and VLA-4 (P=0.014) expressions. VCAM-1 (P=0.001), FLT-3 (P=0.001), CD44 (P=0.011), VLA-4 (P=0.001), and LFA-1 (P=0.001) expressions were higher before HPC mobilization than after HPC mobilization. By contrast, the expression of CXCR4 significantly varied before and after mobilization only among those with successful PBSC mobilization (P=0.002). CONCLUSION: We attempted to identify particular aspects of CAMs involved in CD34+ cell mobilization, which is a highly complex mechanism that involves adhesion molecules and matrix metalloproteases. The mechanism by which CD34+ cell mobilization is activated through proteolytic enzymes is not fully understood. We believe that CXCR4, VLA-4, CD44, and VCAM-1 are the most important molecules implicated in HPC mobilization, particularly because they show a correlation with the yield of CD34+ cells collected via large volume leukapheresis.
Bone Marrow* ; Cell Adhesion Molecules ; Chemokines ; Endothelial Cells ; Hematologic Neoplasms ; Hematopoietic Stem Cells ; Humans ; Integrin alpha4beta1 ; Leukapheresis ; Lymphocyte Function-Associated Antigen-1 ; Lymphoma, Non-Hodgkin ; Metalloproteases ; Multiple Myeloma ; Peptide Hydrolases ; Stem Cells ; Stromal Cells ; Tissue Donors ; Vascular Cell Adhesion Molecule-1

The adhesion and polarization of T lymphocytes involved in the adhesive interaction of lymphocyte function-associated antigen 1 (LFA-1) with its ligand intercellular adhesion molecule 1 (ICAM-1). This study was aimed to investigate the effects of recombinant human granulocyte colony-stimulating factor (rhG-CSF) stimulation in vitro on the adhesion and polarization of CD4⁺ T cells of healthy human in peripheral blood. The peripheral blood mononuclear cells were collected from 12 healthy volunteers. The CD4⁺ T cells were sorted by miniMACS. The sorted CD4⁺ T cells were incubated with rhG-CSF for 24 h, then the adhesion and polarization of CD4⁺ T cells activated by stroma cell-derived factor -1α (SDF-1α) and ICAM-1 were detected by ELISA and inverted microscope. The results showed that the percentage of adhesion CD4⁺T cells in the experimental group (rhG-CSF acting on the healthy adult volunteers) (61.9 ± 5.9)% was lower than that in the control group (healthy adult volunteers without rhG-CSF stimulation) (68.3 ± 7.3)% (P < 0.05). The percentage of polarized CD4⁺T cells in the experimental group (24.3 ± 4.3)% was also lower than that in control group (47.1 ± 5.1)% (P < 0.05). It is concluded that the adhesion and polarization of CD4⁺T lymphocytes can be inhibited after rhG-CSF stimulation.
Aged ; CD4-Positive T-Lymphocytes ; drug effects ; Cell Adhesion ; drug effects ; Cell Movement ; Cell Polarity ; drug effects ; Chemokine CXCL12 ; Granulocyte Colony-Stimulating Factor ; pharmacology ; Humans ; In Vitro Techniques ; Intercellular Adhesion Molecule-1 ; Leukocytes, Mononuclear ; Lymphocyte Activation ; Lymphocyte Function-Associated Antigen-1 ; Middle Aged ; Recombinant Proteins

OBJECTIVETo analyze the clinicopathologic features of extranodal NK/T cell lymphoma, nasal type (ENKTCL-N), to explore the expression of NK cell-associated receptors in ENKTCL-N and the relationship with prognosis, and to establish a prognostic model.

METHODSOne hundred and twenty-six cases of ENKTCL-N were selected from the files of the Department of Pathology, West China Hospital of Sichuan University. The relevant clinical and follow-up data were collected, and the histopathology was reviewed. All specimens were stained immunohistochemically for CD16, ICAM-1 and LFA-1. RT-PCR was used to detect the expression of CD94, NKG2 and KIR. The relationship between the prognosis of ENKTCL-N, clinical features, histopathological characteristics and expression of these markers were also analyzed.

RESULTSENKTCL-N mainly occurred in middle-age and young patients (median age, 41 years). The male to female ratio was 3.2:1. Sites more commonly involved were the nose and upper aerodigestive tract whereas those for the non-nasal type were the skin and gut. Only six cases involved two or more extranodal sites. Most (86.5%, 109/126) of the patients were in clinical stages I/II. The tumors showed predominately medium-sized tumor cells and large-sized tumor cells accounted for only 9.5% (12/126). Coagulative necrosis was present in all cases. The expression rates of CD56, CD16, CD94, LFA-1 and ICAM-1 were 82.6% (95/115), 15.1% (19/126), 55.4% (41/74), 40.5% (51/126) and 0, respectively. The expression rate of NKG2 receptor was 90.5% (67/74) overall. NKG2 receptor expression was independent of CD94. The overall expression rate of KIR receptor was 33.8% (25/74) and KIR receptor restriction was not detected in 20.8% (5/24) of the cases. Follow-up data was available in all patients, with median and average survival time being 15 months and 20.2 months, respectively. Survival analysis showed that prognostic factors included the gender, age, disease type, extranodal involvement, stage, the expression of CD16, LFA-1 and CD94. Cox's proportional hazard regression analysis revealed four factors, age, involved site, stage and CD16 expression, were independent prognostic factors.

CONCLUSIONSThe age, disease type, stage and CD16 expression are independent prognostic factors. Establishment of a prognostic model based on the above four factors can be more accurate in the prognostication of ENKTCL-N. The differences in the clinical features, prognosis, and expression of NK cell-associated receptors are obvious between nasal NK-cell lymphoma and non-nasal NK-cell lymphoma.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; CD56 Antigen ; metabolism ; Child ; Female ; Follow-Up Studies ; Humans ; Intercellular Adhesion Molecule-1 ; metabolism ; Lymphocyte Function-Associated Antigen-1 ; metabolism ; Lymphoma, Extranodal NK-T-Cell ; metabolism ; pathology ; Male ; Middle Aged ; NK Cell Lectin-Like Receptor Subfamily D ; metabolism ; Neoplasm Staging ; Nose Neoplasms ; metabolism ; pathology ; Prognosis ; Proportional Hazards Models ; Receptors, IgG ; metabolism ; Receptors, KIR ; metabolism ; Receptors, NK Cell Lectin-Like ; metabolism ; Survival Rate ; Young Adult

Emerging evidence suggests that gap formation and opening of the endothelial junctions during leukocyte extravasation is actively controlled to maintain the integrity of the vascular barrier. While the role for endothelial cells to this process has been well defined, it is not clear whether leukocytes are also actively contributing to endothelial barrier function. We have recently showed that extravasating leukocytes deposit microparticles on the subendothelium during the late stages of extravasation, which is LFA-1 dependent. Using multiphotonintravital microscopy (MP-IVM) of mouse cremaster muscle vessels in the current work, we show that microparticle formation and deposition maintains the integrity of the microvascular barrier during leukocyte extravasation. Inhibition of neutrophil-derived microparticle formation resulted in dramatically increased vascular leakage. These findings suggest that deposition of microparticles during neutrophil extravasation is essential for maintaining endothelial barrier function and may result in temporal difference between neutrophil extravasation and an increase in vascular leakage.
Animals ; Endothelial Cells ; Leukocytes ; Lymphocyte Function-Associated Antigen-1 ; Mice ; Microscopy ; Monocytes ; Muscles ; Neutrophils

OBJECTIVETo study the effects of TNF-α on ICAM-1 and LFA-1 expression in peripheral blood mononuclear cells (PBMC) of children with febrile seizures (FS).

METHODSSixteen children with FS and 16 age- and gender-matched healthy children were enrolled. The samples of PBMC from FS children were randomized into two groups with or without TNF-α treatment (TNF-α concentration 1.0 ng/mL). PBMC were purified and cultured with a conventional method in vitro. The expression of ICAM-1 and LFA-1 in PBMC was determined by flow cytometry (FCM).

RESULTSICAM-1［(20±9)% vs (14±7)%)］and LFA-1［(43±16)% vs (30±16)%］expression in PBMC in the untreated FS group was significantly higher than that in the normal control group (P<0.05). Compared with the untreated FS group, the treatment with TNF-α remarkably increased the ICAM-1 expression［(27±11)%］(P<0.05). PBMC LFA-1 expression［(52±21)%］in the TNF-α-treated group was higher than that in the untreated FS group, although there were no statistical differences between the two groups.

CONCLUSIONSTNF-α treatment may increase LFA-1 and ICAM-1 expression in PBMC of children with FS.

Child ; Child, Preschool ; Female ; Humans ; Infant ; Intercellular Adhesion Molecule-1 ; blood ; Leukocytes, Mononuclear ; chemistry ; drug effects ; Lymphocyte Function-Associated Antigen-1 ; blood ; Male ; Seizures, Febrile ; immunology ; Tumor Necrosis Factor-alpha ; pharmacology

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

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

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

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