CD4-Positive T-Lymphocytes ; Child ; Cryptococcosis ; immunology ; Humans ; Lymphopenia ; etiology

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

Though the cases of HIV patients with paraquat (PQ) poisoning are rare, we still found the common features. These recovered HIV patients tended to result in much less lung injury, and had low CD4⁺ T lymphocyte levels due to HIV infection, which meant they were under the immunosuppressive condition during treatment. This may be conducive to relieve the acute inflammation and lung fibrosis induced by PQ. Thus, we consider the immunosuppressive therapy for PQ poisoning to be appropriate. However, the drugs used currently may be not optimal for toxic patient. As next step, we will add the CD4⁺ T lymphocyte-targeted immunosuppressive drug to treat PQ poisoning patients.
CD4-Positive T-Lymphocytes/immunology* ; HIV Infections/immunology* ; Humans ; Immunosuppressive Agents/therapeutic use* ; Paraquat/poisoning*

OBJECTIVETo study dynamics of T lymphocyte subsets in severe acute respiratory syndrome (SARS).

METHODSSequential anti-coagulated blood samples were collected from 46 cases of SARS patients during the 1st week, the 2nd week, the 3rd-5th week and the 8th-12th week after the infection. T lymphocyte subsets including CD3+CD4+ cells, CD3+CD8+ cells, naive CD4+ cells (CD4+CD45RA+CD62L+) and activated CD8+ cells (CD8+CD38+) were detected by 3-color flow cytometry. Fifty-six normal healthy blood donors were also detected as normal controls.

RESULTSCompared with the results of normal controls, both of the percentages of CD4+ cells and CD8+ cells of SARS patients were in normal levels during the 1st week, but the cell counts decreased significantly to (306 +/- 140)/mm3 and (270 +/- 143)/mm3, respectively. The cell count of naive CD4+ subset also remarkably decreased to (96 +/- 49)/mm3, and the percentage of CD8+CD38+ subset was higher than that of normal controls [(59.3 +/- 12.6)% vs (44.9 +/- 12.5)%]. During the 3rd-5th week, the CD8+ cell count and the percentage of CD8+CD38+ subset reached normal values, which were (581 +/- 356)/mm3 and (40.1 +/- 17.6)%, respectively. During the 8th-12th week, the cell counts of CD4+ cell [(578 +/- 193)/mm3] and naive CD4+ subset [(176 +/- 64)/mm3] were still less than those of normal controls, while compared with those of the 1st week, the increments were remarkable.

CONCLUSIONST lymphocytes of SARS patients decreased dramatically but could be obviously resumed in a short time. It will take more than 8-12 weeks for CD4+ cell and naive CD4+ subset to reach to normal levels.

Adult ; CD4 Lymphocyte Count ; CD4-CD8 Ratio ; CD4-Positive T-Lymphocytes ; immunology ; Female ; Humans ; Male ; Middle Aged ; Severe Acute Respiratory Syndrome ; immunology ; T-Lymphocyte Subsets ; immunology

OBJECTIVETo investigate the clinical significance of peripheral blood regulatory T cell (Treg) population in patients with extranodal NK/T cell lymphoma, nasal type (ENKL).

METHODSThe peripheral blood CD4+CD25+ Treg cell population was detected by flow cytometry in 41 newly diagnosed ENKL patients between March 2009 and December 2012.

RESULTSThe proportion of CD4+CD25+ Treg cell population increased in ENKL patients compared to healthy donors [(9.64±4.96)% vs(7.31±3.02)%, P<0.05], and decreased significantly after treatment [(5.18±2.19)%, P<0.01]. Patients when got response had significantly lower proportion of Treg cells [(8.79±4.15)%] as compared with those without response [(14.57±6.73)%, P<0.05]. The proportion of Treg population was positively related to the serum lactate dehydrogenass level.

CONCLUSIONThe proportion of peripheral blood Treg cells may be helpful for predicting prognosis and therapeutic efficacy in ENKL patients.

CD4-Positive T-Lymphocytes ; immunology ; CD8-Positive T-Lymphocytes ; Flow Cytometry ; Humans ; Interleukin-2 Receptor alpha Subunit ; immunology ; Lymphoma, T-Cell ; diagnosis ; immunology ; Prognosis

BACKGROUNDVery few researchers have studied the changes in peripheral lymphocyte patterns in adult tuberculosis (TB) and even less researches have been conducted in pediatric TB. In this study, we obtained blood samples from 114 Chinese pediatric TB patients and 116 matched controls to study the association of phenotypic subsets of peripheral lymphocytes with different clinical phenotypes of TB.

METHODSThe subjects were classified as the control group and the TB patients group which were further divided into a pulmonary TB group and an extra-pulmonary TB group (more serious than the former). The distribution of lymphocyte subpopulations, including T lymphocytes, CD4(+) T lymphocytes, CD8(+) T lymphocytes, B lymphocytes, and natural killer (NK) cells, were quantitatively analyzed by flow cytometry.

RESULTSCompared to the healthy controls, TB infection was associated with significantly higher B cell (P < 0.0001), and lower T cell (P = 0.029) and NK cell (P < 0.0001) percentages. Compared to pulmonary TB patients, extra-pulmonary TB was associated with relatively higher B cell (P = 0.073), and lower T cell percentages (P = 0.021), higher purified protein derivative (PPD) negative rate (P = 0.061), and poorer PPD response (P = 0.010). Most pulmonary TB cases were primary pulmonary TB (89.1%), and most extra-pulmonary TB cases had TB meningitis (72.1%).

CONCLUSIONSThis study demonstrates changes in the lymhocyte distribution in children suffering from different clinical phenotypes of TB; such as primary pulmonary TB, and TB meningitis. These patterns may have significance in understanding the pathogenesis and prognostic markers of the disease, and for developing immunomodulatory modalities of therapy.

Adolescent ; Asian Continental Ancestry Group ; B-Lymphocytes ; immunology ; CD4-Positive T-Lymphocytes ; immunology ; CD8-Positive T-Lymphocytes ; immunology ; Child ; Child, Preschool ; Female ; Flow Cytometry ; Humans ; Immunophenotyping ; methods ; Infant ; Killer Cells, Natural ; immunology ; Lymphocytes ; immunology ; Male ; T-Lymphocytes ; immunology ; Tuberculosis ; immunology

BACKGROUNDThe mechanism of chronic immune activation and impairment of HIV-specific immune responses during chronic infection is not fully understood. However, it is known that high immune activation leads to more rapid progression to AIDS. We hypothesize that CD4(+) T cell-mediated viral antigen presentation contributes to this pathologic immune activation in HIV-infected individuals.

METHODSHIV-specific T cells, responding to noninfectious HIV-1 virions as antigen, were measured by flow cytometric assays. These experimental conditions reflect the in vivo condition where noninfectious HIV-1 represents more than 99% of the antigens.

RESULTSCD4(+) T cells purified from HIV-infected individuals were capable of cross presenting exogenous noninfectious HIV-1 virions to HIV-1-specific CD8(+) T cells. Cross presentation required the entry of HIV-1 to CD4(+) T cells and antigen translocation from endoplasmic reticulum to the Golgi complex. Blocking CD4(+) mediated activation of HIV-specific CD8(+) T cells and redirecting the viral antigens to antigen presenting cells improved HIV-specific T cell responses.

CONCLUSIONSOne possible cause of chronic immune activation and impairment of HIV-1 specific T cell responses is represented by HIV-1 harboring CD4(+) T cells cross presenting HIV-1 antigen to activate CD8(+) T cells. This new mechanism provides the first evidence that cross presentation of noninfectious HIV-1 virions play a role in the immunopathogenesis of HIV-1 infection.

Adult ; Antigen Presentation ; CD4-Positive T-Lymphocytes ; immunology ; virology ; CD8-Positive T-Lymphocytes ; immunology ; HIV-1 ; immunology ; Humans ; Lymphocyte Activation ; Male ; Virion ; immunology

Animals ; CD4-Positive T-Lymphocytes ; immunology ; Humans ; Periodontal Diseases ; immunology ; pathology ; T-Lymphocytes, Regulatory ; immunology ; Th1 Cells ; immunology ; Th17 Cells ; immunology ; Th2 Cells ; immunology

CD4-Positive T-Lymphocytes ; immunology ; CD56 Antigen ; analysis ; Cancer Vaccines ; immunology ; Carcinoma, Hepatocellular ; immunology ; Dendritic Cells ; immunology ; Humans ; Liver Neoplasms ; immunology ; T-Lymphocytes, Cytotoxic ; immunology

OBJECTIVETo explore the effect of hypoxia on the peripheral blood T lymphocyte subsets and co-stimulatory molecules in rats so as to provide the basis for studying the intervention measure.

METHODSBefore hypoxia and during hypoxia at 8 000 m for 8 h, 3 d, 6 d and 10 d the change of peripheral blood T lymphocyte subsets and co-stimulatory molecules in rats were detected by flowcytometer with three-color immunofluorescence label.

RESULTSRats were exposed to hypoxia at 8 000 m for 8 hours, and CD3+, CD8+, CD8+ CD28- lymphocyte percentages were significantly decreased (P < 0.01) compared with that before hypoxia. After 3 days of hypoxia, besides aforesaid change, CD4+ CD28+ lymphocyte percentage also prominently decreased (P < 0.01) and CD4+ CD28- prominently increased (P < 0.01). After 6 and 10 days of hypoxia, CD3+, CD4+ lymphocyte percentages were further decreased, while CD8+ CD28+ lymphocyte percentage significantly increased (P < 0.01).

CONCLUSIONAfter exposed to hypoxia at 8 000 m for 8 hours and 3 days, activation of CD8+ and CD4+ T lymphocyte was prominently decreased, while with the prolong of exposed time activation of CD8+ T lymphocyte was significantly increased.

Altitude ; Altitude Sickness ; physiopathology ; Animals ; CD4-Positive T-Lymphocytes ; physiology ; CD8-Positive T-Lymphocytes ; physiology ; Hypoxia ; immunology ; physiopathology ; Lymphocyte Activation ; physiology ; Male ; Rats ; Rats, Wistar ; T-Lymphocytes ; physiology