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La manzanilla de Castilla, dulce o cimarrona (Matricaria recutita o Matricaria chamomilla), es una planta herbácea anual de la familia de las asteráceas, nativa de Europa y de regiones templadas de Asia, que se ha naturalizado en algunas regiones de América, África y Australia. Ha sido utilizada por el hombre desde hace miles de años con diferentes fines medicinales. Se estudió el efecto in vitro de un extracto fluido de esta planta sobre los linfocitos de 20 donantes voluntarios de sangre y de 20 enfermos con diagnóstico de inmunodeficiencia celular, mediante la cuantificación de los linfocitos T por las técnicas de formación de roseta espontánea y activa y el ultramicrométodo inmunocitoquímico (UMICIQ), así como la función fagocítica (índice opsonofagocítico) de los neutrófilos. No se hallaron diferencias estadísticamente significativas en los parámetros estudiados entre las condiciones experimentales con Matricaria y sin esta.Castilla Chamomile, sweet, or maroon (Matricaria recutita or Matricaria chamomilla) is an annual herbaceous plant of the Asteraceae family, native to Europe and temperate zones of Asia, which has become naturalized in parts of America, Africa, and Australia. It has been used by man for thousands of years with different medicinal purposes. We studied the in vitro effect of an extract fluid of this plant on lymphocytes from 20 blood donors and 20 patients with a diagnosis of cellular immunodeficiency. We quantified T lymphocytes by the techniques of spontaneous and active rosette formation, and the immunocytochemical ultramicromethod (UMICIQ) as well as the phagocytic function (opsonophagocytic index) of neutrophils. There were no statistically significant differences in the studied parameters between experimental conditions with Matricaria and without it.

La Passiflora incarnata L. es una especie que se ha utilizado por el hombre con diversos fines. Se estudió el efecto in vitro de un extracto fluido de esta planta sobre los linfocitos de 20 donantes voluntarios de sangre y de 20 enfermos con diagnóstico de inmunodeficiencia celular, mediante la técnica de formación de roseta activa, roseta espontánea y el ultramicrométodo inmunocitoquímico, así como en la función fagocítica de los neutrófilos. No se hallaron diferencias estadísticamente significativas entre las condiciones experimentales sin pasiflora y con pasiflora, en las técnicas de formación de rosetas ni en la expresión de los marcadores de linfocitos CD2 y CD3. Similares resultados se hallaron con la función fagocítica de los neutrófilos en la misma dilución.Passiflora incarnata L. is a species that has been used by man for various purposes. It was studied the effect in vitro of a fluid extract of this plant on lymphocytes from 20 blood donors and 20 patients with cellular immunodeficiency diagnosis, using the technique of active rosette formation, and spontaneous rosette immunocytochemical ultramicromethod and in the phagocytic function of neutrophils. We found no statistically relevant differences between experimental conditions with and without Passiflora, neither in the rosette formation techniques or the expression of lymphocyte markers CD2 and CD3. Similar results were found with the phagocytic function of neutrophils in the same dilution.

El Hibiscus elatus SW (majagua) es una especie que se ha utilizado por el hombre con diversos fines. Se estudió el efecto in vitro de una solución acuosa de las flores de esta planta sobre los linfocitos y neutrófilos de 20 donantes de sangre sanos y de 20 enfermos con diagnóstico de inmunodeficiencia celular, mediante la técnica de roseta activa y espontánea, el ultramicrométodo inmunocitoquímico (UMICIQ) y la prueba de función fagocítica. No se hallaron diferencias estadísticamente significativas entre las condiciones experimentales sin Hibiscus elatus SW y con esta planta (dilución 1:2), en los parámetros estudiados.Hibiscus elatus SW (majagua) is a species used by man due to its diverse ends. Authors studied the in vitro effect of a aqueous solution of flowers from this plant on lymphocytes and neutrophils of 20 healthy blood donors and from 20 ills diagnosed with cellular immunodeficiency using active and spontaneous rosette technique, the immunocytochemical ultramicromethod (UMICIQ) and the phagocytic function test. There weren & rsquo;t significant statistically differences among experimental conditions without Hibiscus elatus SW and with this plant (dilution 1:2) in study parameters.

Type 1 diabetes (T1D) is a chronic autoimmune disease that leads to progressive destruction of pancreatic beta cells. Compared to healthy controls, a characteristic feature of patients with T1D is the presence of self-reactive T cells with a memory phenotype. These autoreactive memory T cells in both the CD4(+) and CD8(+) compartments are likely to be long-lived, strongly responsive to antigenic stimulation with less dependence on costimulation for activation and clonal expansion, and comparatively resistant to suppression by regulatory T cells (Tregs) or downregulation by immune-modulating agents. Persistence of autoreactive memory T cells likely contributes to the difficulty in preventing disease progression in new-onset T1D and maintaining allogeneic islet transplants by regular immunosuppressive regimens. The majority of immune interventions that have demonstrated some success in preserving beta cell function in the new-onset period have been shown to deplete or modulate memory T cells. Based on these and other considerations, preservation of residual beta cells early after diagnosis or restoration of beta cell mass by use of stem cell or transplantation technology will require a successful strategy to control the autoreactive memory T cell compartment, which could include depletion, inhibition of homeostatic cytokines, induction of hyporesponsiveness, or a combination of these approaches. [ABSTRACT FROM AUTHOR]

Background: Immune cells within the tumor can act either to promote growth or rejection of tumor cells. The aim of the present study was to evaluate immune cell markers (number and localization) within the tumor before and during rejection due to radioimmunotherapy, to determine whether there is a change in markers related to rejection and/or tolerance of the tumor cells. Methods: Thirty immunocompetent rats were inoculated with syngeneic rat colon carcinoma cells and 13-14 days later 21 of these rats were treated with 400 MBq/kg of Lu-DOTA-BR96 monoclonal antibodies. The treated animals were sacrificed and dissected 1, 2, 3, 4, 6, and 8 days post-injection in groups of three animals per day (6 animals on day 8); while the nine untreated animals were sacrificed and dissected on day 0. Paraffin sections were used for immunohistochemical staining of CD2, CD3, CD8α, CD68, and CD163 antigens. Positive cells were counted within: vital tumor cell areas, necrotic areas, granulation tissue surrounding and between the tumor cell areas. The change in the number of positive cells over time in tumors treated with radioimmunotherapy in the same location was evaluated with linear regression models. The number of positive cells in various locations and the number of various antigen-positive cells within the same location were also evaluated over time using box plots. Results: There were a higher number of cells expressing immune cell markers in granulation tissue compared with vital tumor cell areas. Cells expressing markers decreased during radioimmunotherapy, and T-cell markers decreased more than macrophage markers in tumors treated with radioimmunotherapy. The expression of CD8α was higher than that of the other T-cell markers evaluated (CD3 and CD2), which could be explained by the additional expression of CD8α by natural killer (NK) cells and a subset of dendritic cells (DCs). The expression of CD68 (all macrophages, DCs, and neutrophils) tended to be higher than that of CD163 (pro-tumor macrophages). Conclusions: In this model, we demonstrated a higher number of positive cells for immune cell markers related to augmenting the immune rejection than immune tolerance of tumor cells in tumors and a decrease in markers during radioimmunotherapy. [ABSTRACT FROM AUTHOR]

Lamina propria lymphocytes (LPLs) are thought to be antigen-activated memory T cells. Yet, they respond better to ligation of the CD2 receptor than the CD3 receptor by mitogenic antibodies. This study defines their constitutive state of activation and relates it to their CD3 hyporesponsiveness. The activated state of LPLs was demonstrated by their heightened display of the activated CD2 epitope, T113. Constitutive CD2 activation was shown by the reduction in spontaneous proliferation when the CD2–CD58 interaction was blocked. LPLs preferentially recognized CD58 rather than the major histocompatibility complex molecules on monocytes, triggering proliferation and interferon-γ (IFN-γ) secretion that was inhibited by blocking the CD2–CD58 interaction. To determine whether CD2 activation of LPLs contributes to their CD3 hyporesponsiveness, they were first stimulated with mitogenic CD2 antibodies and then tested for CD3-induced proliferation. The responses were greatly reduced by prior CD2 stimulation compared with LPLs cultured in medium alone. This effect was not caused by apoptosis or by changes in CD3 expression induced by CD2 triggering. This study shows that LPLs are constitutively activated through CD2, that they preferentially recognize CD58 on monocytes and that CD2 stimulation leads to CD3 hyporesponsiveness. [ABSTRACT FROM AUTHOR]

We have taken advantage of a recently described technique of transformation and immortalization of T lymphocytes using the lymphotropic Herpesvirus saimiri, to achieve long-lasting T-cell lines from gastric cancer patients and healthy volunteers. Blood samples were drawn and T lymphocytes were transformed. Once sustained growth was observed, lines were subjected to phenotypic and functional analyses, and the results compared with freshly isolated peripheral blood mononuclear cells. Cytofluorometric analysis revealed that CD3 and CD45 were found at lower proportion in primary cells from patients than from control individuals (54% vs 75%, p<0.001, 90% vs 96%, p<0.05, respectively), and in HVS-derived T-cell lines (90% vs 98%, p<0.05, 97% vs 100%, p<0.05, respectively). Proliferative analyses showed that primary isolated cells were unable to respond adequately to CD3-, CD2-, and PHA-mediated stimulation, as compared to controls. Similarly, T-cell lines from patients proliferated to a lesser extent when CD3- and CD2-mediated stimuli were considered, especially when simultaneous stimulation via CD3 and CD2 molecules was carried out (47,824 counts per minute [cpm] vs 121,478 cpm, p<0.05). Altogether these results show that the defects reported in T cells from patients with cancer are not exclusively due to tumour-derived factors, since the alterations persist in long-lasting, HVS-transformed, T-cell lines, suggesting that this model seems a suitable one to disclose them. [ABSTRACT FROM AUTHOR]

SUMMARY The aim of this study was to examine in detail the low functional capacity of human intraepithelial lymphocytes (IELs) in response to phytohaemagglutinin (PHA) and CD3 ligation. Human IELs were extracted from jejunal mucosa obtained from patients undergoing gastric bypass operations for morbid obesity and compared to peripheral blood (PB) lymphocytes composed predominantly of CD8+ T cells. Calcium influx ([Ca2+ ]i ) was analysed using Fura-2-loaded cells; IL-2 receptor expression was measured by immunofluorescence and flow cytometry; IL-2 binding was determined using radiolabelled IL-2; IL-2 production was quantified by ELISA; and apoptosis was detected with Apo 2·7 staining. Compared to naive PB CD8+ T lymphocytes, calcium influx by IELs was only transient with CD3 ligation and low in amplitude with PHA. IL-2 receptor expression was reduced after CD3 ligation, yet normal in numbers and affinity after PHA stimulation. Both cell types secreted similar amounts of IL-2. CD3 expression on IELs, but not PB CD8+ T cells, declined upon activation, due partly to incomplete reexpression after modulation. Little apoptosis was found. The partial activation of IELs in response to PHA and CD3 ligation, as manifested by diminished [Ca2+ ]i , resulted in a decline in CD3 expression. [ABSTRACT FROM AUTHOR]

We hypothesize that atopy is associated with a reduced T‐cell function early in life and an imbalance in cytokine production. The purpose of this study was to investigate the expression of and responses to CD2 and CD3 in children who did or did not develop atopic dermatitis early in life. The expression of CD2 and CD3 was analyzed by flow cytometry, and proliferation of CD2 and CD3 was studied by 3H‐thymidine incorporation in phytohaemagglutinin (PHA)‐ and anti‐CD3‐stimulated peripheral blood mononuclear cells (PBMC) of 18‐month‐old children, 25 with and 29 without atopic dermatitis. Exogenous interleukin (IL)‐2 was added to compensate for possible functional differences in accessory cells. Anti‐CD3‐induced secretion of IL‐4, IL‐5, IL‐6, IL‐10, IL‐13, and interferon‐γ (IFN‐γ) was analyzed by enzyme‐linked immunosorbent assay (ELISA). Atopy was associated with a low proportion of CD2+ lymphocytes. Responsiveness to PHA, which activates lymphocytes partly via the sheep erythrocyte receptor, CD2, was reduced in the allergic children. The anti‐CD3‐induced proliferation declined more rapidly with antibody dilution in the allergic than in the non‐allergic children. Atopic dermatitis was associated with high levels of anti‐CD3‐stimulated IL‐5 secretion. The IL‐4/IL‐10 and IL‐4/IFN‐γ ratios were higher in children with elevated total immunoglobulin E (IgE) levels. Skin prick test‐negative children with eczema produced higher levels of IL‐10 than skin prick test‐positive children. In conclusion, atopic children have a reduced T‐cell function. Atopic dermatitis is associated with increased IL‐5 production, while high total IgE levels are associated with high IL‐4/IFN‐γ and IL‐4/IL‐10 ratios. [ABSTRACT FROM AUTHOR]

A recently described chimaeric organ culture system is employed to investigate the effects of antibodies to the CD3 and CD2 cell surface structures on the fate of developing human thymocyte populations. Engagement of CD3 as well as CD2 with reagents that stimulate peripheral human T cell results in the activation-induced death of human thymocytes in organ culture. Death Is preceded by a characteristic phenotyplc change; thymocytes that bear CD45RA (determinants associated with high-molecular-mass isoforms of the leukocyte common antigen family, CD45) are first induced to co-express CD45RO (the low-molecular-mass isoform of CD45), and subsequently lose CD45RA expression. This antigenic change is followed by cellular DNA fragmentation, characteristic of apoptosis. We conclude that engagement of CD3 as well as CD2 can recruit human CD45RA thymocytes into the CD45RO population, where cell death occurs. Our results suggest that this phenotype conversion is a marker for thymocytes destined for programmed cell death. [ABSTRACT FROM PUBLISHER]

An optimal stimulation of CD4+ cells in an immune response requires not only signals transduced via the TcR/CD3 complex, but also costimulatory signals delivered as a consequence of interactions between T-cell surface-associated costimulatory receptors and their counterparts on antigen-presenting cells (APC). The intercellular adhesion molecule-1 (ICAM-l, CD54) efficiently costimulates proliferation of resting, but not antigen-specific, T cells. In contrast, CD28 and CD2 support interleukin (IL)-2 synthesis and proliferation of antigen-specific T cells more efficiently than those of resting T cells. The molecular basis for this differential costimulation of T cells is poorly understood. Cypress-specific T-cell clones (TCC) were generated from four allergic subjects during in vivo seasonal exposure to the allergen. Purified cypress extract was produced directly from fresh collected pollen and incubated with the patients' mononuclear cells. Repeated allergen stimulation was performed in T-cell cultures supplemented with purified extract and autologous APC. The limiting-dilution technique was then adopted to generate allergen-specific TCC, which were also characterized by their cytokine secretion pattern as Th0 (IL-4 plus interferon-gamma) or Th2 (IL-4). Costimulation-induced proliferation or apoptosis was measured by propidium iodide cytofluorometric assay. By cross-linking cypress-specific CD4+ and CD8+ T-cell clones with either anti-CD3 or anti-CD2, anti-CD28, and anti-CD54 monoclonal antibodies, we demonstrated that CD4+ clones (with Th0- or Th2-type cytokine production pattern) undergo programmed cell death only after anti-CD3 stimulation, whereas costimulation with either anti-CD54 or anti-CD28 protects target cells from apoptosis. The costimulation-induced protection from apoptotic death was associated with a significant rise in IL-4 secretion in both Th0 and Th2-type clones. In contrast. cypress-specific Th0 CD8+ clones were more susceptible to stimulation-induced apoptosis via either anti-CD3 or anti-CD2, alone or in combination with anti-CD54 or anti-CD28, thus displaying only slight but nonsignificant modifications in the pattern of IL-4 secretion. The death-promoting costimulatory effects were not observed with highly purified normal resting CD4+ or CD8+ lymphocytes. Taken together, these results suggest that TcR engagement by an allergen in the context of functionally active APC induces activation-dependent cell death of some, perhaps less specific, cells, and this may be an important homeostatic mechanism through which functional expansion of allergen-specific T cells is regulated during an ongoing immune response. [ABSTRACT FROM AUTHOR]

Recent studies from several laboratories suggest that the rate of postnatal maturation of T-cell function(s) associated with in vitro activation may be slower in children at high genetic risk for atopy (HR), compared to their normal (low risk; LR) counterparts. The present study compared the in vitro activity of the function-associated surface molecules CD2, CD3 and CD28 in panels of 27 HR and 13 LR infants, with a reference panel of 10 adults. employing assay systems involving T-cell stimulation with MoAbs against these molecules. The response maxima induced by saturating levels of the MoAbs were equivalent in all 3 groups, but Tcells from the HR infants required 10-50 fold higher levels of anti-CD3 stimulation to attain their maximum response, relative to adults (p = 0.02); T-cells from LR infants were also less responsive to anti-CD3 than adults, but these differences were smaller and did not attain statistical significance. It is suggested that these differences are attributable to varying proportions of competent T-memory cells (which respond to low levels of anti-CD3) in PBL from these populations, the postnatal accumulation of which proceeds slowest in the HR group. [ABSTRACT FROM AUTHOR]