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

Cellular immunity is an important component of human immune system and plays a crucial role in the fight against tumor cell or invasive pathogens. Researches on cell-based immunotherapy have long been focused on eliciting tumor-specific CD8+ cytotoxic T lymphocytes (CTL) because of their potent killing activity and their ability to reject transplanted organs. However, the resulting treatments have been surprisingly poor at inducing complete tumor rejection, in both the experimental models and clinical trials. The CD4+ T cells has been studied mainly for their role as helpers for CD8+ CTL, even suggesting that the tumor-specific CD4 T regulatory cells could act as suppressors of antitumor responses. Recent studies indicated that CD4+T cells are not a pure cell lineage with single function, but a cell population with complex functions. Moreover CD4+ T cells may not only be helper cells, but also act as potent effector cells or partners with NK cells that can clear a wide variety of tumors. In a word, the antitumor potential of effector CD4+ T cells might have been underestimated. In this article, the classification and differentiation of CD4+ T cells, the function and secreted cytokines of CD4+ T cells, the CD4+ T cells and tumor immune, the tumor-immuno regulatory effects of CD4+ T cells, and clinical researches of CD4+ T cells are reviewed.
CD4-Positive T-Lymphocytes ; classification ; cytology ; immunology ; Cytokines ; metabolism ; Cytotoxicity, Immunologic ; Humans ; Immunity, Cellular

OBJECTIVE: To explore the better freezing protocol to preserve peripheral blood monuclear cells (PBMCs), islets antigen-specific T cells responses compared with freshly isolated samples in type 1 diabetic (T1D) patients. METHODS: The T cell Workshop Committee of the Immunology of Diabetes Society (IDS-TCW) organized the Freezing Study I and we were one of the 9 centers in the world to participate in the study. According to the two standardized T cell freezing protocols (warm and cold) to freshly isolated PBMCs in terms of recovery, viability, cell subset composition (FACS) and performance in Enzyme-linked immunospot (ELISPOT) assays, we chose 5 newly onset T1D patients and 5 age and sex matched healthy controls. Besides the protocols, all the freezing reagents and antigens were also centralized. The antigens used in ELISPOT were labeled blindedly. RESULTS: 1) Although warm frozen-thawed (W) samples had a slightly higher recovery rate (61.2% vs 60.1%, P>0.05) and viability (77.5% vs 74.9%, P>0.05) as compared with the cold frozen ones (C), the difference was not significant. 2) Both protocols led to a relative loss in monocytes as compared with the fresh samples (F) [3.2±1.1% (C) and 3.0±0.9% (W) vs 7.0±1.1% (F), both P<0.05], while other subsets including CD4+T, CD8+T, B cells, NK cells and NKT cells didn't. 3) Freezing and fresh samples showed similar IFN-γ secretion responses to polystimuli in ELISPOT. Irrespective of the freezing protocol, recall antigen Pediacel and islet antigen-reactive responses were both lower in the frozen cells compared with fresh PBMCs. The stimuli index (SI) of GADspecific T cell response in the fresh samples from T1D patients was 5.1, higher than that of frozen samples with either cold protocol (1.3) or warm one (1.4) (both P<0.05). Only fresh samples from T1D showed significantly higher GAD-specific T cell responses than the healthy controls no matter in SI (5.1 vs 0.9, P<0.05) or spot forming cells (8.1 vs 0.1, P<0.05), whereas the frozen samples did not show such difference. CONCLUSION More studies are needed to verify a freezing method to bring comparable islets antigen specific T cell responses in T1D patients to fresh PBMCs.
Adult ; CD4-Positive T-Lymphocytes ; immunology ; CD8-Positive T-Lymphocytes ; immunology ; Cryopreservation ; Diabetes Mellitus, Type 1 ; blood ; immunology ; Female ; Humans ; Islets of Langerhans ; immunology ; Leukocytes, Mononuclear ; cytology ; Male ; T-Cell Antigen Receptor Specificity ; immunology ; T-Lymphocytes ; cytology ; immunology ; Young Adult

BACKGROUND: We investigated the characteristics of the mononuclear cells remaining in the leukoreduction system (LRS) chambers of Trima Accel(R) in comparison with those of standard buffy coat cells, and evaluated their potential for differentiation into dendritic cells. METHODS: Twenty-six LRS chambers of Trima Accel(R) were collected after platelet pheresis from healthy adults. Flow cytometric analysis for T, B, NK, and CD14+ cells was performed and the number of CD34+ cells was counted. Differentiation and maturation into dendritic cells were induced using CD14+ cells seperated via Magnetic cell sorting (MACS(R)) Seperation (Miltenyi Biotec Inc., USA). RESULTS: Total white blood cell (WBC) count in LRS chambers was 10.8x108 (range 7.7-18.0x108). The median values (range) of proportions of each cells were CD4+ T cell 29.6% (18.7-37.6), CD8+ T cell 27.7% (19.2-40.0), B cell 5.5% (2.2-12.1), NK cell 15.7% (13.7-19.9), and CD14+ cells 12.4% (8.6-32.3) respectively. Although total WBC count was significantly higher in the buffy coat (whole blood of 400 mL) than the LRS chambers, the numbers of lymphocytes and monocytes were not statistically different. The numbers of B cells and CD4+ cells were significantly higher in the buffy coat than the LRS chambers (P<0.05). The median value (range) of CD34+ cells obtained from the LRS chambers was 0.9x10(6) (0.2-2.6x10(6)). After 7 days of cytokine-supplemented culture, the CD14+ cells were successfully differentiated into dendritic cells. CONCLUSIONS: The mononuclear cells in LRS chambers of Trima Accel(R) are an excellent alternative source of viable and functional human blood cells, which can be used for research purposes.
Adult ; B-Lymphocytes/cytology/immunology ; CD4-Positive T-Lymphocytes/cytology/immunology ; CD8-Positive T-Lymphocytes/cytology/immunology ; Cell Differentiation ; Dendritic Cells/*cytology/immunology ; Flow Cytometry ; Humans ; Killer Cells, Natural/cytology/immunology ; Plateletpheresis/*instrumentation

Maturation of T cells in thymus plays key roles in antigen-specific immune response. In maturation, thymocytes undergo positive and negative selection. The MHC restriction of T cell is determined in positive selection. The tolerance of T cells to autoantigen is acquired during negative selection. Quantitation (avidity) theory points out that difference of avidity between thymocytes and stroma cells leads to difference in the signals integrated inside cells. When the signal reaches a particular threshold, positive or negative selection takes place. In this article, the selection mechanism and the relationship between positive and negative selection are mini-reviewed.
Animals ; CD4-Positive T-Lymphocytes ; cytology ; immunology ; CD8-Positive T-Lymphocytes ; cytology ; immunology ; Cell Differentiation ; Humans ; Receptors, Antigen, T-Cell ; immunology ; Signal Transduction ; T-Lymphocytes ; immunology ; Thymus Gland ; cytology

The aim of this study was to explore the regulatory function of interleukin-6(IL-6) on human Th17 cells. Human peripheral blood CD4(+) T cells were purified from healthy donors by anti-CD4 monoclonal antibody (mAb) conjugated microbeads. The experiment was divided into 2 groups. Test group in which CD4(+) T cells (1 × 10(6)/ml) were stimulated by human recombined IL-6 (20 ng/ml) for 4 days; control group in which CD4(+) T cells did not stimulated by IL-6. The concentrations of IL-17 protein in the supernatants were assayed by enzyme-linked immunosorbent assay (ELISA), and quantity of Th17 cells were detected by flow cytometry. The results showed that as compared to control group, IL-17 protein level in the supernatants of CD4(+) T cells significantly increased in IL-6 stimulated group: (337.05 ± 189.09 pg/ml; vs 15.07 ± 12.70 pg/ml) (p < 0.05). Furthermore, the percentage of Th17 cells in cultures of CD4(+) T cells stimulated by IL-6 was significantly higher than that in control group (4.05% ± 0.30% vs. 2.81% ± 0.44%)(p < 0.01). It is concluded that IL-6 promotes the expansion of Th17 cells in vitro.
CD4-Positive T-Lymphocytes ; cytology ; immunology ; Cells, Cultured ; Humans ; Interleukin-6 ; pharmacology ; Lymphocyte Activation ; immunology ; Th17 Cells ; drug effects ; immunology

To study the effects of supernatant derived from acute myeloid leukemia (AML) cell lines on proliferation and apoptosis of CD4(+) and CD8(+) T cell subsets and to investigate the mechanism by which AML escapes from immune recognition, lymphocytes were labeled with CFSE and were stimulated with anti-CD3 and anti-CD28 in presence or absence of supernatants from three AML cell lines (HL-60, NB4, U937). After culture, cell suspensions were labeled with 7AAD and CD4 PE (or CD8 PE). Cells were then detected by flow cytometry and their proliferation and apoptosis were analyzed. The results showed that supernatants from two of three cell lines (HL-60 and NB4) inhibited the proliferation of CD4(+) and CD8(+) T cells, and the degree of inhibition showed a dose-dependent way. Similarly, the apoptosis of stimulated CD4(+) T cells was inhibited, but stimulated CD8(+) T cells remained unaffected by supernatant from HL-60 and NB4. In contrary, the apoptosis of proliferative CD8(+) T cells were increased significantly by HL-60 and NB4 supernatant. It is concluded that soluble factors derived from AML cell lines inhibit the proliferation of CD4(+) and CD8(+) T cells and induce the apoptosis of proliferative CD8(+) T cells, that may be one of the mechanisms by which the immunity was suppressed.
Apoptosis ; physiology ; CD4-Positive T-Lymphocytes ; cytology ; immunology ; CD8-Positive T-Lymphocytes ; cytology ; immunology ; Cell Proliferation ; Cells, Cultured ; Culture Media ; HL-60 Cells ; Humans ; Leukemia, Myeloid, Acute ; immunology ; pathology ; T-Lymphocytes ; cytology ; Tumor Cells, Cultured ; U937 Cells

OBJECTIVETo investigate the frequencies and distribution of CD4+ T cells and CD8+ T cells as well as the changes of immune activation in gastric mucosa of HIV-infected individuals.

METHODS42 HIV-infected individuals were recruited into this investigation, and 36 patients had definite diagnosis of clinical stage. Biopsy of gastric mucosal tissues was performed by fiberoptic gastroscope including 10 normal people as a control group. Then, immunohistochemistry was used to detect expression of CD4, CD8 and CD38 in gastric mucosa, and the distinctions among three groups were analyzed with LEICA Qwin image analysis system.

RESULTS(1) Compared with asymptomatic HIV carriers and control group, CD4 T cells remarkably decreased in the gastric mucosa of AIDS patients (P < 0.01). In gastric mucosa of asymptomatic HIV carriers, there were still some CD4+ T cells in lymphoid follicles and stroma where CD4+ T cells were unevenly distributed, the frequency of CD4+ T cells was not significantly different between asymptomatic HIV carriers and control group (P > 0.05); (2) Phenomenon of CD8+ T cells infiltrating mucosal epithelium and gland was general in HIV-infected individuals. CD8+ T cells took on local excessive hyperplasia in gastric mucosa of some individuals. As compared with control group, CD8+ T cells markedly increased in gastric mucosa of infected individuals (P < 0.01), but the distinction of asymptomatic HIV carriers and AIDS patients was not significant (P > 0.05); (3) CD38-expressing cells mainly distributed over gastric mucosal surface to superficial layer(1/3-2/3 layer) of HIV-infected individuals, and was more intensive than control group (P < or = 0.01), but there was not noticeable difference between asymptomatic HIV carriers and AIDS patients (P > 0.05).

CONCLUSIONThe frequencies and distribution of gastric mucosal CD4+ T cells of HIV-infected individuals were closely correlated with progression of disease. Disfunction of mucosal immune system which was resulted from HIV infection and injury of CD4+ T cells could be an important cause of CD8+ T cells increasing and CD38-expressing enhancement.

ADP-ribosyl Cyclase 1 ; genetics ; immunology ; Adult ; CD4-Positive T-Lymphocytes ; cytology ; immunology ; CD8-Positive T-Lymphocytes ; cytology ; immunology ; Female ; Gastric Mucosa ; immunology ; Gene Expression ; HIV Infections ; genetics ; immunology ; HIV-1 ; immunology ; Humans ; Lymphocyte Count ; Male ; Middle Aged

OBJECTIVE: To study the effect of electro- acupuncture at Zusanli acupoint in regulating perioperative cell immune functions in rats. METHODS: Forty-two SD rats were divided into blank control group (=6), model group (=18), and electroacupuncture group (=18). The rats in the latter two groups underwent thigh incision and femoral dissection under anesthesia; the rats in electro-acupuncture group received electro-acupuncture at bilateral Zusanli acupoint for 15 min before anesthesia and 1 h after the surgery. The rats in the model group and electro-acupuncture group were sacrificed at 6 h, 24 h, and 72 h after the operation and blood samples were taken from the ventricle for analyzing CD3, CD4, and CD8 T cell subpopulations and calculation of CD4/CD8 using flow cytometry. ELISA was used to detect the levels of interleukin-1 (IL-1) and IL-6. RESULTS: The CD3 T cell subpopulation was significantly lower in the model group and electro-acupuncture group than in the blank group at 6 h and 24 h after the operation. At 72 h after the operation, CD3 subpopulation levels still remained low in the model group, but recovered the control level in electro-acupuncture group. At each time point of measurement, CD3 level was significantly lower in the model group than in the electro-acupuncture group. CD4 level in the model group was significantly lowered at 6 h and 24 h after the operation, and recovered the control level at 72 h. In the electro-acupuncture group, CD4 level was significantly lowered at 6 h after the operation, but recovered the control level at 24 h. At 24 h and 72 h, the levels of CD4 were significantly lower in the model group than in the electro-acupuncture group. CD8 level underwent no significant changes after the operation in either the model group or electro-acupuncture group. CD4/CD8 was significantly lowered at 24 h and 72 h after the operation in the model group but showed no significant variation in the electro-acupuncture group. Compared with that in the control group, IL-1 level was significantly lowered in both the model group and electroacupuncture group at 6 h, 24 h, and 72 h after the operation, and was significantly lower in the model group than in the electroacupuncture group at these time points. IL-6 level increased significantly in the model group and the electro- acupuncture group at 6 h and 24 h. at 72 h, IL-6 level was obviously lowered in the electro-acupuncture group but remained elevated in the model group. CONCLUSIONS Electro-acupuncture alleviates postoperative immune suppression and promotes recovery of the immune function in rats, suggesting a protective effect of electro-acupuncture at Zusanli acupoint on cellular immune function after surgery.
Acupuncture Points ; Animals ; CD4-Positive T-Lymphocytes ; cytology ; immunology ; CD8-Positive T-Lymphocytes ; cytology ; immunology ; Electroacupuncture ; methods ; Femur ; surgery ; Flow Cytometry ; Humans ; Immunity, Cellular ; Perioperative Period ; Rats ; Rats, Sprague-Dawley ; T-Lymphocyte Subsets ; cytology ; immunology

OBJECTIVETo investigate the relation between CD4(+) and CD8(+) T lymphocyte infiltration and apoptosis of the neurons in the local traumatic brain tissue after brain trauma in rats.

METHODSIn rat models of brain trauma, the changes in the number of CD4(+) and CD8(+) T lymphocytes and the apoptosis of neurons in the local traumatic brain tissue were observed by immunohistochemistry at different time points after brain trauma.

RESULTSTwenty-four hours after brain trauma, a significant increase in the number of CD4(+) and CD8(+) T lymphocytes occurred in the injured brain tissue, both reaching the highest levels on day 10, at the point of which the number of CD4(+) cells increased by about 15 folds and that of CD8(+) cells by about 20 folds compared with the control groups. The CD4(+) and CD8(+) T lymphocytes both began to decrease 30 days after the injury. A similar pattern of alterations was found in the apoptosis of neurons in the local brain tissue. Correlation analysis demonstrated a close positive correlation between the changes in CD4(+) and CD8(+) lymphocyte numbers and the number apoptotic neurons in the injured brain tissue.

CONCLUSIONSBrain trauma induces obvious increases in CD4(+) and CD8(+) T lymphocytes and enhanced cellular immune response in the injured brain tissue to mediate neuronal apoptosis and further exacerbate the brain tissue injuries.

Animals ; Apoptosis ; immunology ; Brain Injuries ; immunology ; pathology ; CD4-Positive T-Lymphocytes ; cytology ; immunology ; CD8-Positive T-Lymphocytes ; cytology ; immunology ; Female ; Immunity, Cellular ; Male ; Neurons ; immunology ; pathology ; Random Allocation ; Rats ; Rats, Sprague-Dawley