Neuronal synapse is the critical structure of neuronal network. Immune system is mainly consisted of invisible network. Recently, evidence showed that leukocyte synapses between immune cells named as immunological synapses (IS), were formed under some functional conditions to form temporal local network. In fact, they are dynamic structures, which can be classified into synapse and kinase. Different leukocytes have different synapses. Inflammatory and leukemic cells showed special patterns of IS. Similar structure is also observed in some viral infected lymphocytes, which is called virological synapse (VS). This is one of the mechanisms for viral transmission, not only enhancing the transmission efficiency but also mediating the escape from antibody neutralization, leading persistent infection. Recently the flower-like poly synapses was reported by French scientists. This is a multi-tunneling nanotube flower-like structure on cell surface. We had observed this kind of structure in EB virus infected human leukemic cell line J6-2. In this paper, the structure and function of leukocyte synapses are reviewed combined with authors' own work. Their significance is discussed.
Humans ; Immunological Synapses ; immunology ; physiology ; Leukocytes ; cytology ; immunology ; physiology ; virology

Colony-Forming Units Assay ; Cryopreservation ; methods ; Fetal Blood ; cytology ; Hematopoietic Stem Cells ; cytology ; Humans ; Immunotoxins ; immunology ; Leukocytes, Mononuclear ; cytology ; Ricin ; immunology ; T-Lymphocytes ; cytology ; immunology ; Time Factors

The study was purposed to explore the quantity, morphology and immunophenotype of dendritic cells (DC) acquired by co-cultivated system with 3 types of cytokines and sodium selenite (Se) from peripheral blood mononuclear cells (PBMNCs), and to investigate the effects of Se on inducing the cytotoxic T lymphocyte (CTL) to get specific anti-leukemic activity in vitro by DC pulsed with K562 cell frozen-thawed antigen (antigen cell loading). PBMNCs isolated from healthy donors were cultured in RPMI 1640 medium contained 10% FBS supplied with 3 cytokines (rhGM-CSF, rhIL-4, TNF-alpha) for 4 days, DCs harvested were divided into 4 groups, DCI: DC alone; DCII: DC + Se (adding 0.5 micromol/L of Se); DCIII: DC + K562 (pulsed with lysed K562 cells); DCIV: DC + Se + K562. Morphology of DCs was observed under microscope at day 7. The CD1a, CD40, CD83, and CD86 were detected by FCM. Cytotoxicity of T cells induced by DC were measured with LDH release test at day 12. The level of IL-12 in supernatant of cultured DCs were determined with ELISA. The results indicated that at 7th day DC in 4 groups showed characteristic morphology, the colony numbers of 4 groups were all higher than those before cultivation. There were no obvious differences of morphology and colony counts between DCI group and DCII group. The colony numbers of DCIII group and DCIV group increased, as well as the ratio of suspended cells enhanced. The expressions of CD1a, CD40, CD83 and CD86 in 4 groups of DC were significantly higher than those in PBMNC group (p < 0.01), the expressions of CD1a and CD40 in 4 groups of DC did not display significant difference (p > 0.05), the expressions of CD83 and CD86 in both DCIII group and DCIV group were all higher than those in DCI group and DCII group (p < 0.01), but their expressions of CD83 and CD86 in DCI and DCII were not significantly different (p > 0.05), as well as those in DCIII group and DCIV group. With the ratio of 25:1 between E:T, killing rate of CTL on K562 cells in 4 DC groups were 15.3 +/- 2.3%, 26.3 +/- 3.7%, 28.2 +/- 4.5% and 36.2 +/- 3.7% respectively, all obviously higher than those of T cell group without being sensitized by DCs (5.9 +/- 2.4%) (p < 0.01), The CTL effect in DCIV group was the highest, which was higher than those in other 3 DC groups (p < 0.01); the effects in both DCII and DCIII group were also higher than that in DCI group (p < 0.01), but their difference between DCII and DCIII groups did not show significance (p > 0.05). The levels of IL-12 in supernatant of DCI, DCII, DCIII and DCIV groups were 257.0 +/- 64.2, 328.1 +/- 43.9, 323.0 +/- 53.5 and 353.9 +/- 46.2 pg/ml respectively, all significantly higher than that in supernatant of T cell alone group without being sensitized by DCs (35.27 +/- 27.1 pg/ml) (p < 0.01), The levels in DCII, DCIII and DCIV groups were all higher than that in DCI group (p < 0.01), but their levels between DCII, DCIII and DCIV groups were not of significant difference (p > 0.05). It is concluded that matured DCs can be successfully obtained from PBMNCs by a culture system contained rhGM-CSF, rhIL-4 and TNF-alpha with or without low-dose of Se (0.5 micromol/L) in vitro. Using K562 cell frozen-thawed antigen, DC express more adhesive molecules and co-stimulating molecules (CD83, CD86), and increase the secretion of IL-12, as well as the killing effects of CTL on special target cells. Low dose of Se did not showed effects on quantity and morphology of matured DC harvested, as well as their expression of mature phenotypes, it raised levels of IL-12 secreted by DCs, reaching the same level as using K562 cell frozen-thawed antigen, and it showed synergistic effect on induction of CTL with K562 cell frozen-thawed antigen.
Cells, Cultured ; Cytokines ; pharmacology ; Dendritic Cells ; cytology ; immunology ; Humans ; K562 Cells ; Leukocytes, Mononuclear ; cytology ; Sodium Selenite ; pharmacology ; T-Lymphocytes ; immunology ; T-Lymphocytes, Cytotoxic ; cytology ; immunology

To evaluate the separation of T lymphocyte subsets by immunomagnetic beads and to find optimization of strategy for specific binding of antibody-coated beads to cells, two strategies to isolate enriched T lymphocyte subpopulation CD4+ T cells and CD8+ T cells from small volumes (< 5 ml) of peripheral blood by using immunomagnetic beads or complement cytotoxicity method were compared. The purity and activity of CD4+ T cells and CD8+ T cells were measured by using flow cytometry, trypan-blue dye exclusion test, etc. The results showed that the yields of CD4+ T lymphocytes and CD8+ T lymphocytes by using immunomagnetic beads were (94.2 +/- 1.4)% and (93.8 +/- 3.0)% respectively, higher than those of control group and the group of using completement cytotoxicity method (P < 0.05). At the same time, the yields of CD4+ T lymphocytes and CD8+ T lymphocytes by using complement cytotoxicity method were (76.0 +/- 2.8)% and (77.0 +/- 3.0)% respectively, higher than those of unenriched group (P < 0.05). The trypan-blue dye exclusion test confirmed that there were no influences on activity of CD4+ T cells and CD8+ T cells when immunomagnetic beads were used for separation of these cells from peripheral blood. It is concluded that the immunomagnetic bead method has a higher efficiency for separation of CD4+ T cells and CD8+ T cells from peripheral blood than complement cytotoxic method, especially for small sample. This method has no influence on activity and proliferation of T lymphocyte subpopulations, and would be expected to establish conditions for research of biological characteristics of CD4+ T cells and CD8+ T cells in future.
CD4-Positive T-Lymphocytes ; cytology ; CD8-Positive T-Lymphocytes ; cytology ; Flow Cytometry ; Humans ; Immunomagnetic Separation ; methods ; Leukocytes, Mononuclear ; cytology ; immunology

To investigate the characteristics of interstitial inflammatory cells and possible involvement of nudelta T cells, 16 renal allograft biopsies showing chronic rejection were stained by immunohistochemical method and correlated with the data of peripheral blood evaluated by flow cytometry. For immunophenotyping, fresh frozen sections were stained with monoclonal antibodies against CD3, CD4, CD8, CD68, CD56, TCRdelta1 and HLA DR. Paraffin embedded tissue was stained with CD45RO, CD20-Cy and CD68. Nine cases of nonspecific tubulointerstitial change and 4 cases of nonallograft tubulointerstitial nephritis were used as a control. Inflammatory infiltration was present in all cases studied. T cells predominated in the interstitium of chronic rejection and were followed by macrophages and B cells. The degree of interstitial infiltration of frozen section was not accordant with that of paraffin sections. Allografts with nonspecific tubulointerstitial changes or tubulointerstitial nephritis of native kidneys showed similar distribution pattern in terms of type and degree. However, the degree of infiltrate did not give any statistical significance among groups. The CD4/CD8 ratios in interstitial infiltrates were less than 1.0 in 6 cases and was not accordant with those of peripheral blood. Proportion of nudelta T cells increased over 10% in 2 cases in tissue and in 3 cases in peripheral blood. In 3 cases of chronic rejection in which both tissue and blood results were available, there was no concordance of CD4/CD8 or nudeltaT/CD3 between them. Tubular expression of HLA DR was, however, present only in 4 cases of chronic rejection. In conclusion, T lymphocytes were predominant regardless of diagnosis or disease activity. T lymphocyte subset did not give any suggestion as to the diagnosis or disease activity in chronic rejection. Furthermore nudelta T cells had only limited value. Lymphocytic subsets in peripheral blood would not be predictors of tissue destruction in chronic rejection.
Flow Cytometry ; Graft Rejection/*immunology ; Human ; Kidney/cytology/*immunology ; Kidney Transplantation/*immunology ; Leukocytes, Mononuclear/*immunology ; Phenotype ; Receptors, Antigen, T-Cell, gamma-delta/immunology ; Support, Non-U.S. Gov't

To investigate the characteristics of interstitial inflammatory cells and possible involvement of nudelta T cells, 16 renal allograft biopsies showing chronic rejection were stained by immunohistochemical method and correlated with the data of peripheral blood evaluated by flow cytometry. For immunophenotyping, fresh frozen sections were stained with monoclonal antibodies against CD3, CD4, CD8, CD68, CD56, TCRdelta1 and HLA DR. Paraffin embedded tissue was stained with CD45RO, CD20-Cy and CD68. Nine cases of nonspecific tubulointerstitial change and 4 cases of nonallograft tubulointerstitial nephritis were used as a control. Inflammatory infiltration was present in all cases studied. T cells predominated in the interstitium of chronic rejection and were followed by macrophages and B cells. The degree of interstitial infiltration of frozen section was not accordant with that of paraffin sections. Allografts with nonspecific tubulointerstitial changes or tubulointerstitial nephritis of native kidneys showed similar distribution pattern in terms of type and degree. However, the degree of infiltrate did not give any statistical significance among groups. The CD4/CD8 ratios in interstitial infiltrates were less than 1.0 in 6 cases and was not accordant with those of peripheral blood. Proportion of nudelta T cells increased over 10% in 2 cases in tissue and in 3 cases in peripheral blood. In 3 cases of chronic rejection in which both tissue and blood results were available, there was no concordance of CD4/CD8 or nudeltaT/CD3 between them. Tubular expression of HLA DR was, however, present only in 4 cases of chronic rejection. In conclusion, T lymphocytes were predominant regardless of diagnosis or disease activity. T lymphocyte subset did not give any suggestion as to the diagnosis or disease activity in chronic rejection. Furthermore nudelta T cells had only limited value. Lymphocytic subsets in peripheral blood would not be predictors of tissue destruction in chronic rejection.
Flow Cytometry ; Graft Rejection/*immunology ; Human ; Kidney/cytology/*immunology ; Kidney Transplantation/*immunology ; Leukocytes, Mononuclear/*immunology ; Phenotype ; Receptors, Antigen, T-Cell, gamma-delta/immunology ; Support, Non-U.S. Gov't

OBJECTIVETo prepare tumor antigen peptides from HL-60 cells and to induce specific immune response.

METHODSHL-60 antigen peptides were obtained using techniques including freezing and thawing, heat precipitation and acid precipitation. The stimulating effect of the in vitro Hsp70 binding HL-60 peptides on PBMC and the proliferation of stimulated PBMC were observed by T cell activation test. The cytotoxicity of proliferated PBMC is detected by incubating HL-60 cells or K562 cells with PBMC respectively.

RESULTSThe obtained tumor antigen peptides were a peptides mixture. The mixed peptides could activate PBMC and cause PBMC proliferation in vitro after presented by Hsp70. The proliferated PBMC showed specific cytotoxicity to HL-60 cells but not to K562 cells.

CONCLUSIONThe method for preparing of human leukemia tumor antigen peptides used in this paper is simple and easy; the obtained antigen peptides can induce specific immune response in vitro.

Cell Division ; HL-60 Cells ; HSP70 Heat-Shock Proteins ; immunology ; Humans ; K562 Cells ; Killer Cells, Natural ; immunology ; Leukocytes, Mononuclear ; cytology ; immunology ; Neoplasm Proteins ; immunology ; Peptides ; immunology

To explore the possibility of in vitro induction of cord blood cell-derived lymphocytes into cytotoxic T lymphocytes (CTL) with anti-leukemia specificity, umbilical cord blood (UCB)-derived mononuclear cells were cultured with multiple cytokines to generate dendritic cells (DC) in vitro. Leukemia cells were irradiated with (137)Cs and activated by premature cytokines. The characteristics of maturation of DC were evaluated through morphology examination and flow cytometry. DC pulsed with leukemic antigens were co-cultured with lymphocytes. Cytotoxicity of the CTL to corresponding leukemic cells was measured with lactate dehydrogenase-release assay. The results showed that UCB-derived monocytes could be induced into typical DC in all of the 12 samples. Expression of immunological markers such as CD1a(+), HLA-DR(+), CD86(+), CD83(+) on DC were significantly up-regulated (P < 0.05). DC presenting leukemic antigens generated leukemia-specific CTL with a killing rate of (44.76 +/- 17.42)% at the E:T ratio of 50:1 against AML cells and a killing rate of (8.50 +/- 4.25)% at the E:T ratio of 50:1 against ALL cells. Whereas, these CTL present almost no killing effect on the mononuclear cells collected from the same patients in complete remission phase. It is concluded that (1) it is possible to induce UCB-derived monocytes into mature DC with typical morphology. (2) Cord blood derived mature DC presenting leukemia antigen can generate leukemia-specific CTL with vigorous cytotoxic activity against the same leukemia blasts and low killing activity against bone marrow cells of the same patients in complete remission phase.
Cells, Cultured ; Coculture Techniques ; Cytotoxicity, Immunologic ; immunology ; Dendritic Cells ; cytology ; immunology ; Female ; Fetal Blood ; cytology ; immunology ; Humans ; K562 Cells ; Leukemia ; immunology ; pathology ; Leukocytes, Mononuclear ; cytology ; immunology ; Male ; T-Lymphocytes, Cytotoxic ; immunology

OBJECTIVETo explore the role of indirect antigen presentation pathway on the immunogenecity of epidermal cells.

METHODSHuman epidermal cells (HEC), allogeneic human peripheral blood lymphocytes (PBL) and mononuclear cells (PBM, including monocytes) were isolated and cultured in vitro. HECs were transfected by human-originated CTLA4Ig-adenovirus vector. The CTLA4Ig expression was observed. Allogeneic PBLs or PBMs were added to the transfected and non-transfected HECs with simple cultured PBLs and PBMs as the control. The proliferation of PBL and PBM was determined by (3)H-TdR incooperation.

RESULTSHECs could be successfully transfected by CTLA4Ig-adenovirus vector and expressed corresponding proteins. The non-transfected HECs could stimulate slight proliferation of allogeneic PBLs (P < 0.05) and stimulate remarkable proliferation of PBMs (including monocytes) (P < 0.05). The proliferation reaction of PBLs and PBMs decreased significantly (P < 0.05) after being stimulated by HEC which was modulated by CTLA4Ig genes.

CONCLUSIONIndirect antigen presentation pathway might play important roles in the HEC immunogenicity which could be evidently inhibited by CTLA4Ig.

Adenoviridae ; genetics ; Antigen Presentation ; immunology ; physiology ; Antigens, CD ; Antigens, Differentiation ; genetics ; immunology ; CTLA-4 Antigen ; Cell Division ; immunology ; Cells, Cultured ; Coculture Techniques ; Epidermis ; cytology ; immunology ; metabolism ; Genetic Vectors ; genetics ; Humans ; Leukocytes, Mononuclear ; cytology ; immunology ; Lymphocytes ; cytology ; immunology ; Signal Transduction ; Transfection

The latent membrane protein 2 (LMP2) is a kind of protein expressed by EBV-infected cells. This study was aimed to investigate whether the stimulation of peripheral blood mononuclear cells with peptides induces EBV-specific cytotoxic T lymphocytes (CTL). The peptides were mixture of LMP2 protein and available for people with different HLA types. Peripheral blood sample was collected from a patient with EBV-associated hemophagocytic syndrome. The mononuclear cells were isolated and cultured to obtain dendritic cells (DCs). Immature DCs were pulsed with MIX-LMP2 and added with different maturation-promoting factors. The auto-T lymphocytes were stimulated weekly with the harvested mature DCs loaded with MIX-LMP2, and totally for two times. Part of isolated lymphocytes was cultured without any stimulation as control. T-cell receptor (TCR) beta spectratyping was used to analyze the distribution of different T cell subgroups before and after culture. The phenotype of T lymphocytes was determined by flow cytometry. The IFN-gamma assay was used to estimate specific cytoxic activity of the cultured T cells. The results showed that the distribution of TCRbeta was changed according to analysis of TCR spectratypes. From the distribution of gene families of TCRbeta, the T lymphocytes were oligoclonal before culture, but shifted to a polyclonal after culture in vitro like the normalization of TCR diversity, suggesting the subgroups of lymphocyte could return to normal. The percentage of CD3+, CD3+CD8+ CD3+ CD45RA- CD45 RO+ on T lymphocytes from freshly isolated mononuclear cells were 70.73%, 42.99%, 27.56% respectively. After being stimulated twice with DC loaded with MIX-LMP2, they further increased to 95.17%, 52.54% and 81.41%. The percentages of CD3-CD56+ NK cells and CD4+CD35+ FOXP3+ regulation T cells seldom changed, from 2.12%, 0.03% to 2.35%, 0.02% respectively. The increase of CD3+CD45RA-CD45RO+ cells obviously indicated that most naive T cells could be activated. ELISA for IFN-gamma showed that when DCs loaded with LMP2 peptide were used as target cells, IFN-gamma level secreted by the T cells stimulated with LMP2 peptide-pulsed DCs was 805+/-16 pg/ml and 1729+/-49 pg/ml, the IFN-gamma level secreted by T cells stimulated twice with LMP2 peptide-pulsed DCs was 956+/-23 pg/ml and 2325+/-58 pg/ml respectively at effector-target ratios of 10:1 and 10:2. They were both significantly higher than that secreted by T cells without any stimulation (441+/-27 pg/m and 557+/-19 pg/ml) (p<0.05). But DCs unpulsed with LMP2 peptide were used as target cells, there were no significant differences between the T cells stimulated with LMP2 peptide-pulsed DCs and the T cells without stimulation (p>0.05). It is concluded that the antigen specific T cells recognizing EBV epitopes can be obtained by using DCs pulsed with MIX-LMP2 peptide in vitro, meanwhile the distribution of T cell subgroups can be changed and normalized.
Antigens, Viral ; immunology ; Cells, Cultured ; Coculture Techniques ; Cysteine Endopeptidases ; immunology ; metabolism ; Dendritic Cells ; immunology ; metabolism ; Epitopes, T-Lymphocyte ; immunology ; Epstein-Barr Virus Infections ; immunology ; Herpesvirus 4, Human ; immunology ; Humans ; Leukocytes, Mononuclear ; cytology ; T-Lymphocytes ; cytology ; immunology