Lymphocyte Subsets Defined by Monoclonal Antibodies in Human Pregnancy

ABSTRACT: Using monoclonal antibodies, indirect immunofluorescence, and flow cytometry, the proportions and absolute numbers of various lymphocyte subsets in peripheral blood have been measured in normal human pregnancy. Groups of ten women were studied at 12, 28, and 36 weeks of gestation and compared with 16 nonpregnant control women. The percentage of T cells (OKT3 +) was constant throughout pregnancy, and this was confirmed in three women studied serially prior to and throughout early pregnancy. A slight fall in the proportion of helper cells (OKT4 +) and rise in the proportion of suppressor cells (OKT8 +) was observed at 12 and 28 weeks, but these changes, and the resulting fall in helper/suppressor ratio, were not statistically significant. Absolute lymphocyte counts determined by white cell count and differential were lower during pregnancy. The absolute numbers of T cells, helper cells, suppressor cells, and Ia-bearing cells (mainly B cells) were significantly lower at 36 weeks' gestation. T cells and helper cells were significantly reduced in absolute number at 12 weeks' gestation. There was no change in the ratio of T cells to B cells at any stage of gestation. The lack of any significant change in the balance between helper and suppressor cells in peripheral blood suggests that these cells are not important in the immune adaptation to pregnancy.     

Lymphocyte Subsets in Habitual Abortion

ABSTRACT: Lymphocyte subpopulations were characterized by means of monoclonal antibodies in 25 women with habitual abortion and 21 muciparous normal women. Compared to nonpregnant women (N = 8), pregnant normal women were associated with significantly lower helper-to-suppressor ratios (1.71 ± 0.41 versus 2.37 ± 0.66). In contrast in pregnant women with habitual abortion (N = 13) the ratio remained high (2.32 ± 0.73). Failure to increase the number of suppressors and a significant rise in helpers caused this increased ratio. We discuss the possible mechanisms and etiological importance of this finding in habitual abortion.     

Heterogeneity of immunological abnormalities in ataxia-telangiectasia

Peripheral blood mononuclear cells from five patients with ataxia-telangiectasia were evaluated for their reactivity with a panel of monoclonal antibodies directed against T-cell subsets and for theirin vitro functions in a pokeweed mitogen-induced immunoglobulin biosynthesis assay. All the patients had significantly reduced proportions of cells identified by monoclonal antibodies to subpopulations of T lymphocytes with helper activity (OKT4 and 5/9) and produced low amounts or no IgA and IgGin vitro. Immunoglobulin biosynthesis was increased by the addition of normal x-irradiated peripheral blood mononuclear cells in one of three patients, suggesting a helper T-cell deficiency in this patient and intrinsic B-cell defects in the other two. Two patients had increased proportions of cells identified by a monoclonal antibody to a subpopulation of T lymphocytes which includes suppressor T cells (OKT8), and their cells were able to suppress immunoglobulin biosynthesis by peripheral blood mononuclear cells from normal donors. These findings indicate heterogeneous disturbances of immunoregulatory mechanisms in ataxia-telangiectasia.     

Thymic Hormone-Induced Accelerated Development of Antibody Responsiveness to Sheep Red Blood Cells in the Newborn Mouse*

ABSTRACT: The influence of thymic preparations on the kinetics of the development of PFC response to sheep erythrocytes was tested in mice 0 to 4 weeks old. Soluble thymic factor (STF) or thymic epithelial culture supernatant (TES) was prepared from the thymuses of C57B1/6 mice. STF was injected to gravid mice on day 13 or on day 18 of gestation. A marked acceleration in the appearance of PFC to SRBC was noted only in the offspring from those mothers having received STF on day 18. The ability to generate anti-SRBC response in vitro by splenocytes from 1-to 4-week-old mice was significantly improved in the presence of TES. The accelerated appearance of the response to a T-dependent antigen is attributed to increase in the ratio of T helper/T suppressor cells resulting from differentiation and/or clonal expansion under the influence of STF crossing of the placental barrier in the materno-fetal direction.     

结核病患者外周血CD4+记忆T细胞亚群的检测及意义

目的:探讨结核病患者外周血总CD4+T细胞及抗原特异性记忆T细胞的产生及分布规律,了解记忆T细胞在结核病发病中的作用.方法:以荧光标记的抗CD4、CCR7、CD45RA三种抗体共染色,用流式细胞仪检测结核病患者外周血总CD4+记忆T细胞,以荧光标记的抗人CD4、CD154、CCR7、CD45RA四种抗体共染色,检测结核...     

Immunoregulatory Function of Human Cord Blood Lymphocytes on Immunoglobulin Production

ABSTRACT: The functional maturity of human umbilical cord blood B lymphocytes and the immunoregulatory activity of cord T lymphocytes were assessed by measuring the in vitro immunoglobulin production by B cells from either cord or adult blood. Supernatants from 48-hr pokeweed-mitogen (PWM) stimulated cord or adult lymphocyte cultures were added to cord or adult B cell cultures in the presence of PWM; a significant amount of immunoglobulin was produced in adult B cell cultures only. Adult B or T cells were then cocultured with cord T or B cells; a significant amount of immunoglobulin was again found only in adult B cell cultures. These results indicated that cord B cells were functionally immature and that cord helper T cell function was adequate but masked by excessive suppressor activity. Indeed, addition of cord T cells but not of allogeneic adult T cells to PWM stimulated adult lymphocyte cultures inhibited their immunoglobulin production; this confirmed cord T cells' increased suppressor activity. Cord T cells were not intrinsically suppressive since they failed to suppress immunoglobulin production by Epstein-Barr Virus (EBV) transformed B cells. They could be activated, however, by PWM or allogeneic cells (in mixed lymphocyte cultures) and their effect was mediated via soluble factor(s) as demonstrated by the suppressor effect of these culture supernatants on immunoglobulin production by unfractionated adult lymphocytes. In contrast, when these supernatants were added to T cell-depleted adult lymphyocyte cultures, enhancement rather than suppression was observed. These results indicated that the soluble factor(s) released by Cord T lymphocytes was not suppressing per se but induced suppression through activation of suppressor cells.     

Deficiency of suppressor T-cells in insulin-dependent diabetes mellitus: an analysis with monoclonal antibodies

Peripheral blood from 25 patients with insulin-dependent diabetes mellitus was examined for any alteration in the proportions and or functions of immunoregulatory T-cell subsets, defined with monoclonal antibodies. Ten of 25 (40%) patients demonstrated deficiency of OKT8+ (suppressor/cytotoxic) T-cells. Eight of these 10 patients had abnormally high ratios of OKT4+/OKT8+ T-cells. Nine of 10 patients with abnormally low proportion of OKT8+ T-cells had deficient concanavalin A-induced suppressor cell activity against the proliferative response of autologous or allogeneic lymphocytes to phytohemagglutinin. No correlation was observed between the deficiency of suppressor T-cells and the control of diabetes. Therefore, it is likely that the deficiency of suppressor cells is related to insulin-dependent diabetes mellitus itself and not to the metabolic changes that are associated with diabetes mellitus. This study demonstrates both quantitative and qualitative deficiency of suppressor T-cells in at least some patients with insulin-dependent diabetes, that might play an important role in the pathogenesis and autoimmune manifestations of a proportion of patients with insulin-dependent diabetes mellitus.     

T Cell Help to B Cells in Germinal Centers: Putting the Jigsaw Together

The germinal center (GC) reaction supports the processes of affinity maturation and class switching in B cells that result in long-lasting humoral immunity. CD4⁺ T follicular helper cells (Tfh) participate in the GC reaction to help B cells. However, recent studies highlight the heterogeneity of CD4⁺ T cells in GCs, which confounds the understanding of Tfh cells. Based on many recent studies, we have tried to form a working model on the niche of Tfh cells in GCs. We have also addressed whether Tfh cells are a distinct lineage and how they may be generated to help B cells.     

Impairment of T immunoregulatory activities in the induction of antibody specific response in aged humans

T helper (Th) and T suppressor (Ts) functions on the induction of specific antibody response have been studied in 80 aged individuals by means of a plaque-forming cell assay. Of the subjects 45.2% exhibited a reduction of Ts activity on Ig production by adding Concanavalin A (Con A) to cultures on day 0, while 35.7% of aged donors showed a decrease of Th functions by supplementation of Con A on day 2. A small number of individuals displayed a combined deficit (Th + Ts). Furthermore, these defects seem to be related to soluble suppressive factors which might adhere to cell surface. In fact, preincubation of peripheral blood mononuclear cells (PBMC) before their addition to cultures and resuspension in fresh medium normalized the immunoregulatory defects. On the other hand, overnight supernatants from old PBMC transferred to young PBMC cultures induced the same deficit observed in the aged cell suspensions. Finally, Zinc chloride supplementation to cultures was able to correct the deficient Th activity only. These data suggest an additional defect of immunoregulation in the elderly.     

Lymphocyte Subsets in the Neonates of Preeclamptic Mothers

ABSTRACT: With the aid of specific monoclonal antibodies, indirect immunofluorescence, and flow cytometry, peripheral blood lymphocyte populations were studied in 12 preeclamptic mothers and compared with those of ten normal patients at term. As well, lymphocyte subsets from newborns of these preeclamptic mothers and ten normal patients at term were studied. Lymphocytes were labelled with murine monoclonal antibodies directed against T cells and subsets of helper cells, suppressor/cytotoxic cells and natural killer cells. Cord blood lymphocytes of neonates from preeclamptic mothers showed a statistically significant reduction of total T cells, helper cells, and natural killer cells as compared to control. A significant reduction in helper/ suppressor ratio was also observed. It is hypothesized that the differences in the immune system of the neonates in the preeclamptic group may be due to the stress of intrauterine malnutrition secondary to uteroplacental insufficiency.     

Human Fetal/Neonatal Suppressor Activity: Relation Between OKT Phenotypes and Sensitivity to Prostaglandin E2 in Maternal and Neonatal Lymphocytes

ABSTRACT: T lymphocytes from human fetuses and newborns strongly and spontaneously suppress various adult cell functions (i.e. T-cell proliferation, B-cell differentiation, and Ig synthesis). The precise phenotype of the suppressor cell is controversial. In this investigation we use cord T-cell subsets negatively selected by the panning technique or by complement-mediated lysis using the monoclonal antibodies OKT4 and OKT8. Cord T cells deprived of the OKT4⁺ subpopulation exerted only a marginal suppressor activity (12 ± 7 as compared to 73 ± 4% of unfractionated T cells) on the proliferation of maternal cells in our PHA-stimulated co-culture assay using sex chromosomes as markers for dividing cord (male) and maternal cells. The suppressive effect was direct, i.e. not mediated by induction of maternal OKT8⁺ suppressor effector cells. Cord and maternal T-cell subsets were also tested for their sensitivity to exogenous prostaglandin E₂ (PGE₂) at doses varying between 1.4 × 10^?5 and 1.4 × 10^?9 M. Both maternal OKT4^? and OKT8^? T-cell subsets were highly sensitive to suppression by PGE₂. In contrast, cord OKT8^? T cells were essentially nonsensitive at all doses of PGE₂ used, whereas cord OKT4^? T cells were significantly suppressed at four out of five concentrations tested (1.4 × 10^?6 through 1.4 × 10^?9). Our results suggest a direct correlation between the phenotypes of the cord-suppressor and maternal-target T cells and their sensitivity to PGE₂.     

Autologous mixed lymphocyte reaction in man. II. Histamine-induced suppression of the autologous mixed lymphocyte reaction by T-cell subsets defined with monoclonal antibodies

Human peripheral blood mononuclear cells were separted into T and non-T cells by E-rosette formation. The influence of histamine (10^–8–10^–3 M) on the proliferative response of T cells in autologous and allogeneic mixed lymphocyte cultures (MLC) was studied. Pretreatment of responder T cells but not of stimulator non-T cells with histamine for 24 hr resulted in a markedly diminished proliferative response in both autologous and allogeneic MLC. A minimum of 4 hr of incubation of T cells with histamine was required to inhibit autologous MLC. Furthermore, T cells pretreated with histamine followed by mitomycin C treatment, when cocultured with fresh autologous T cells, suppressed their proliferative response in both autologous and allogeneic MLC. Analysis with OKT₄ and OKT₈ monoclonal antibodies revealed that histamine-induced suppressor T cells were contained in OKT ₈ ⁺ -cell subset. Hitamine-treated OKT ₄ ⁺ cells had no suppressive effect on the proliferative responses of autologous T cells. Supernatants of T cells cultured with histamine for 24 hr also suppressed both autologous and allogeneic MLC responses of fresh T cells, suggesting that the suppression could be mediated by a soluble suppressor factor(s). Experiments with H₁ and H₂ agonists and antagonists indicated that histamine-induced activation of suppressor T cells and the production of a soluble suppressor factor(s) were mediated through histamine type 2 receptors.     

A practicable method for the analysis of T lymphocyte subsets in CSF lymphopleocytosis

Summary A practicable indirect immunofluorescence technique for the analysis of surface markers of cerebrospinal fluid (CSF) cells is described. Preliminary results in 10 patients with acute or chronic CSF lymphoplcocytosis of different etiology showed an almost uniform pattern of cell subsets. The majority of CSF cells represented OKT3-positive T lymphocytes with a mean helper (OKT4-positive) to suppressor (OKT8-positive) ratio of 3,4 to 1.Supported by the Deutsche Forschungsgemeinschaft (To 63/2–4, SFB 200, B5)     

Suppressor-cell dysfunction in children with histiocytosis-X

Suppressor-cell activity of peripheral blood mononuclear cells were examined and lymphocyte subsets analyzed in children with histocytosis-X and in healthy, age-matched subjects. Suppressor-cell function was assessed by two methods, the indomethacin stimulation of mitogen-activated cultures and the concanavalin A-inducible suppressor-cell assay. The results of these two assays indicate that children with active disease have significantly decreased suppressor-cell activity. Additionally, the percentage and absolute number of OKT8⁺ lymphocytes were decreased in children with active disease. Suppressor-cell activity and lymphocyte subsets returned to normal, baseline levels with disease remission. This study documents for the first time suppressor-cell dysfunction and supports previous investigations in which suppressor T lymphocytes are deficient in children with active disease. These findings may explain certain clinical manifestations seen in children with histiocytosis-X.