Antiendothelial cell antibodies (AECA) have been detected in the sera of patients of autoimmune diseases showing vasculitis. Using IgM-ELISA, we found AECA in 42 (56%) of 75 sera samples from patients with Behcet's disease in a previous study. All of the 15 AECA-positive sera of Behcet's disease patients had an increased expression of the intercellular cell adhesion molecule-1 (ICAM-1), 93.3% of the sera induced the vascular cell adhesion molecule-1 (VCAM-1), and 100% of the serum induced the E-selectin molecule on human dermal microvascular endothelial cells (HDMEC). After stimulation of HDMEC with AECA-positive sera of Behcet's disease patients, the expression of ICAM-1 and VCAM-1 on HDMEC increased significantly at 4 hours, reaching a peak at 16 hours. Expression of E-selectin was induced at 1 hour after stimulation with a peak at 4 hours and it decreased thereafter. Adherence of T lymphocytes to HDMEC increased significantly after stimulation with AECA-positive sera from Behcet's disease patients. Also, the adherence of T lymphocytes to HDMEC increased at 4 hours and returned to its normal level at 48 hours. These results show that AECA-positive sera of Behcet's disease patients are capable of activating HDMEC to promote the adherence of T lymphocytes to increase the expression of ICAM-1, VCAM-1, and E-selectin on the cell surfaces. The whole process may play an important role in the pathogenesis of vasculitis in Behcet's disease.
Antibodies/physiology* ; Antibodies/blood ; Behcet's Syndrome/immunology ; Behcet's Syndrome/blood* ; Blood Physiology ; Cell Adhesion/physiology ; Cells, Cultured ; Endothelium, Vascular/physiology* ; Endothelium, Vascular/immunology* ; Endothelium, Vascular/cytology ; Human ; Microcirculation/physiology ; Skin/blood supply* ; T-Lymphocytes/physiology*

BACKGROUNDLittle is known about basophil with respect to the different signaling transduction pathways involved in spontaneous, cytokine or anti-IgE induced adhesion and how this compares to IgE-dependent and IgE-independent mediator secretion. The purpose of the present study was to investigate the roles of beta1 and beta2 integrins in basophil adhesion as well as hosphatidylinositol 3-kinase (PI3K), src-kinases and extracellular signal regulated kinase (ERK) 1/2 in basophil adhesion and histamine release (HR).

METHODSBasophils (purity of 10% - 50%) were preincubated with anti-CD29 or anti-CD18 blocking antibodies before used for adhesion study. Basophils were preincubated with the pharmacological inhibitors wortmannin, PP1, PD98059 before used for adhesion and HR study. Cell adherence to bovine serum albumin (BSA) or fibronectin (Fn) was monitored using cell associated histamine as a basophil marker and the histamine was measured by the glass fiber assay.

RESULTSBasophil spontaneous adhesion to Fn was inhibited by anti-CD29. Interleukin (IL)-3, granulocyte/macrophage colony stimulating factor (GM-CSF) induced adhesion to BSA was inhibited by anti-CD18. Wortmannin at 1 micromol/L and PP1 at 20 micromol/L strongly interfered with, whereas PD98059 at 50 micromol/L weakly inhibited basophil spontaneous adhesion to Fn. One micromol/L wortmannin strongly inhibited IL-3, IL-5, GM-CSF and anti-IgE induced adhesion to BSA. PP1 at 20 micromol/L partly inhibited anti-IgE induced adhesion. Fifty micromol/L PD98059 marginally inhibited IL-5, weakly inhibited anti-IgE, partly inhibited GM-CSF induced adhesion. Wortmannin, PP1 and PD98059 inhibited anti-IgE (1:100 or 1:1000) induced basophil HR in a dose dependent manner. They inhibited calcium ionophore A23187 (10 micromol/L, 5 micromol/L) induced basophil HR in a dose dependent manner, but to different extend with PP1 being the most efficient.

CONCLUSIONSBasophil spontaneous adhesion to Fn is mediated by beta1-integrins whereas cytokine induced adhesion to BSA is mediated by beta2-integrins. PI3K, src-kinases and ERK1/2 play distinct signaling roles in basophil adhesion and HR. PI3K is the key player while ERK1/2 is the weakest participant.

Androstadienes ; pharmacology ; Antibodies, Anti-Idiotypic ; pharmacology ; Basophils ; physiology ; CD18 Antigens ; physiology ; Cell Adhesion ; Extracellular Signal-Regulated MAP Kinases ; physiology ; Flavonoids ; pharmacology ; Histamine Release ; Humans ; Integrin beta1 ; physiology ; Phosphatidylinositol 3-Kinases ; physiology ; Signal Transduction ; physiology

OBJECTIVETo study the effect of endogeneous gangliosides (Gls) on integrin alpha2beta1-mediated adhesion of neuroblastoma cells to collagen (Col).

METHODSNeuroblastoma SK-N-SH cell line was cultured in the modified eagle's medium with the presence of 10 mum D-threo-1-phenyl-2-decanolamino-3-morphinolin-1-propanol (D-PDMP), an inhibitor of glucosylceramide synthase. Flow cytometry was used to detect the expression of integrin alpha2beta1 in the cell line. The effects of Mg2(+) and monoclonal antibodies to integrin alpha2beta1 on the adhesion of the cell line to immobilized Col were observed. The adhesion cell number was measured with the BCA method and presented with absorptance A570.

RESULTSThere was a high expression of integrin alpha2beta1 in the SK-N-SH cell line without D-PDMP treatment. Endogenous Gls in the cells were almost depleted after 6-day exposure to D-PDMP, but the integrin alpha2beta1 expression was not significantly changed. 1 mmoL/L Mg2(+) treatment increased significantly the number of adhesion cells in the SK-N-SH cell line. The adhesion to Col of the SK-N-SH cells exposed to D-PDMP which Gls was depleted was significantly reduced compared with the control SK-N-SH cells treated with 1 mmoL/L Mg2(+) (A570: 0.33 +/- 0.016 vs 0.57 +/- 0.033; P < 0.01). After endogeneous Gls was added into the Gls-depleted SK-N-SH cells, the adhesion of the cells was restored (A570: 0.52 +/- 0.035). The adhesion of SK-N-SH cells was significantly blocked by anti-alpha2 and anti-beta1 monoclonal antibodies, with A570 of 0.31 +/- 0.018 and 0.36 +/- 0.021 respectively.

CONCLUSIONSEndogenous tumor Gls increases neuroblastoma cell adhesion to Col by regulating the function of integrin alpha2beta1, but has no effects on the integrin expression. It is suggested that tumor Gls may play a role in migration, invasion and metastasis of tumor cells.

Antibodies, Monoclonal ; immunology ; Cell Adhesion ; Cell Line, Tumor ; Collagen ; physiology ; Gangliosides ; physiology ; Humans ; Integrin alpha2beta1 ; physiology ; Magnesium ; pharmacology ; Morpholines ; pharmacology ; Neuroblastoma ; pathology

The interactions between blood cells and blood cells or blood cells and endothelium of blood vessel are mainly mediated by adhesion molecules. The role of adhesion molecules is diverse in vivo, which involved in adhesion, migration, differentiation and signal transduction of blood cells. The function of adhesion molecules is necessary to maintain the normal structure and fulfill many physiological processes of these cells. Therefore, the abnormal or deficiency of their expression and function will disrupts normal physiological processes and results in clinical disease. In this paper, several generic classes of adhesion molecules, including the integrins, the selectins, the immunoglobulin superfamily and others are introduced, and a lot of related physiopathological status, such as inflammation, hemostasis, arteriosclerosis, thrombosis and stem cell homing are discussed. The studies on the adhesion molecules of blood cells will contribute not only to understand the pathogenesis of some disorders, but also to search new targets in diagnosis and treatment of these diseases.
Animals ; Antibodies, Monoclonal ; therapeutic use ; Arteriosclerosis ; etiology ; Blood Cells ; chemistry ; Cell Adhesion Molecules ; antagonists & inhibitors ; physiology ; Humans ; Inflammation ; etiology ; Integrins ; physiology ; Selectins ; physiology ; Thrombosis ; etiology

OBJECTIVETo study the role of integrin alpha 6 in cell attachment, spread, survival/proliferation and differentiation of human hepatocellular carcinoma (HCC) BEL-7402 cells on various substrates by monoclonal antibody against the extracellular domain of alpha 6 subunit (IA6ED McAb).

METHODSThe effect of McAb on attachment and spread of BEL-7402 cells on LN or FN substrate was examined. MTT analysis was used to examine the cell survival/proliferation, gelatin zymography to the matrix metalloproteinases (MMPs) secreted by BEL-7402 cells, and microparticle immunoabsorbent kit to AFP secretion while the cells were cultured on LN-, FN- or Matrigel-coated substrates.

RESULTSThe cell attachment, spread and survival/proliferation were inhibited. Moreover importantly, the malignant cell dedifferentiation and abnormal differentiation on LN-coated substrate were also strongly inhibited by IA6ED McAb.

CONCLUSIONLN and integrin alpha 6 regulate human HCC cell phenotypes of survival/proliferation and differentiation. The phenotypes of dedifferentiation and abnormal differentiation can be reversed by blocking the interaction between integrin alpha 6 and LN using IA6ED McAb, which may lower metastatic potency of tumor cells.

Antibodies, Monoclonal ; pharmacology ; Carcinoma, Hepatocellular ; pathology ; Cell Adhesion ; drug effects ; Humans ; Integrin alpha6 ; immunology ; physiology ; Laminin ; physiology ; Liver Neoplasms ; pathology ; Phenotype ; Receptors, Laminin ; physiology ; Tumor Cells, Cultured

Excretory/secretory proteins (ESP) from Toxoplasma gondii were analyzed to define the function in the penetration process into host cells. Whole ESP obtained at 37 degrees C were composed of 15 bands with molecular mass of 110, 97, 86, 80, 70, 60, 54, 42, 40, 36, 30, 28, 26, 22, and 19 kDa. Five ESP of 86, 80, 42, 36, and 28 kDa were reacted with monoclonal antibodies (mAb), named as Tg386 (microneme), Tg485 (surface membrane), Tg786 (rhoptry), Tg378, and Tg556 (both dense granules), respectively. The ESP was released by a temperature-dependent/-independent manner and all at once whenever ready to pour out except Tg786. Each ESP was not exhausted within the parasite but the amount was limited. Tg786 was released continuously with increment, whereas Tg378 and Tg556 were ceased to release after 3 and 4 hr. Dense granular Tg378 and Tg556 were released spontaneously and constitutively before the entry into host cells also. The entry of T. gondii was inhibited by all the mAbs differentially. And the parasite deprived of ESP was inhibited to enter exponentially up to 90.1%. It is suggested that ESP play an essential function to provide appropriate environment for the entry of the parasite into host cells.
Animals ; *Antibodies, Monoclonal ; *Antibodies, Protozoan ; Antigens, Protozoan/*analysis/physiology ; Mice ; Mice, Inbred BALB C ; Support, Non-U.S. Gov't ; Temperature ; Toxoplasma/*chemistry/pathogenicity

Antibodies, Viral ; physiology ; Betacoronavirus ; physiology ; Clinical Laboratory Techniques ; Coronavirus Infections ; diagnosis ; Cross Reactions ; physiology ; Enzyme-Linked Immunosorbent Assay ; Fluorescent Antibody Technique, Indirect ; Humans ; Pandemics ; Pneumonia, Viral ; diagnosis ; SARS Virus ; physiology

AIMTo investigate the distribution of cation channel of sperm 1 (CATSPER1) protein and the presence of CATSPER1 mRNA in human testis and ejaculated spermatozoa. The influence of anti-human CATSPER1 antibody upon human sperm motility was used to evaluate the function of human CATSPER1 and to estimate its possible use as a target for immunocontraception.

METHODSHuman ejaculated sperm from normozoospermic donors (n = 12) and liquid nitrogen frozen human testis were used for the study of mRNA and protein expression of CATSPER1 by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry, respectively. Spermatozoa from normozoospermic donors (n = 12) were individually processed using a swim-up procedure and were then incubated with CATSPER1 antibody at final concentrations of 20, 4 and 0.8 microg/mL. After 1, 2 and 6 h incubation, progressive motility and fast progressive motility were measured by means of computer-assisted semen analysis.

RESULTSCATSPER1 transcript was detected in both human testis and each human ejaculated semen sample. CATSPER1 protein expressed in the membrane of spermatid and was localized in the principal piece of the sperm tail. The application of CATSPER1 antibody at all concentrations significantly inhibited both progressive motility and fast progressive motility after 1, 2 and 6 h incubation, and significant dose-dependent changes were observed.

CONCLUSIONCATSPER1 is meiotically and post-meiotically expressed in human testis tissue. CATSPER1 mRNA in human ejaculated spermatozoa could be a more feasible target for study and infertility screening than testis biopsy. In addition, our results suggest that human CATSPER1 could be a possible target for immunocontraception.

Antibodies ; Calcium Channels ; genetics ; immunology ; Ejaculation ; Humans ; Male ; Meiosis ; Protein Biosynthesis ; RNA, Messenger ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Semen ; physiology ; Sperm Motility ; immunology ; physiology ; Spermatozoa ; cytology ; physiology ; Testis ; cytology ; physiology ; Transcription, Genetic

To explore the roles of regulatory peptides in the process of various anaphylactic inflammation of the airway, we observed the influence of four peptides, i.e., vasoactive intestinal peptide (VIP), epidermal growth factor (EGF), endothelin-1 (ET-1), and calcitonin gene-related peptide (CGRP), on the adhesion of eosinophil (EOS) to unstimulated and O(3)-stressed bronchial epithelial cells (BEC). From the experiments we observed that VIP and EGF decreased EOS adherence to O(3)-stressed BEC and downregulated airway inflammation; ET-1 and CGRP increased the adhesion of EOS to BEC in the inflammatory process; and CGRP aggravated O(3)-stressed reactions. The effects of ET-1 and CGRP were inhibited by W(7)and H(7). Anti-ICAM-1 antibody inhibited the adhesion of EOS to BEC, which brings to light that EOS adherence to BEC may be related to the expression of ICAM-1 of BEC.
Animals ; Antibodies ; pharmacology ; Bronchi ; cytology ; Cell Adhesion ; drug effects ; physiology ; Cells, Cultured ; Endothelin-1 ; pharmacology ; Eosinophils ; physiology ; Epidermal Growth Factor ; pharmacology ; Epithelial Cells ; physiology ; Female ; Intercellular Adhesion Molecule-1 ; immunology ; physiology ; Male ; Rabbits ; Vasoactive Intestinal Peptide ; pharmacology

CD43 (sialophorin, leukosialin) is a heavily sialylated surface protein expressed on most leukocytes and platelets including T cells. Although CD43 antigen is known to have multiple and complex structure, exact function of CD43 in each cell type is not completely understood. Here we evaluated the role of CD43 in Fas (CD95)-induced cell death in human T lymphoblastoid cell line, Jurkat. Crosslinking CD43 antigen by K06 mAb increased the Fas-mediated Jurkat cell apoptosis and the augmentation was inhibited by treatment with caspase inhibitors. Further, CD43 signaling of Jurkat cells induced Fas oligomerization on the cell surfaces implying that CD43 ligation have effects on early stage of Fas-induced T cell death. These also suggest that CD43 might play an important role in contraction of the immune response by promotion of Fas-induced apoptosis in human T cells.
Receptor Aggregation/immunology ; Jurkat Cells ; Humans ; Caspases/metabolism ; Apoptosis/*immunology ; Antigens, Surface/metabolism ; Antigens, CD95/metabolism/*physiology ; Antigens, CD43/metabolism/*physiology ; Antibodies, Monoclonal/metabolism