Specific and non-specific components in the triggering of proliferative and cytotoxic responses of T lymphocytes with different cell density

We hve analyzed the functional behavior of lymphocyte subsets separated on the basis of cell density. Low and high density subpopulations were cultured in FCS, alone or with allogeneic irradiated PBL, and then examined for proliferation and cytotoxic activity against autologous (responder) and allogeneic (stimulator) PHA-induced blasts, K562 and Daudi. In the high density subset proliferation and generation of anti-K562 and anti-Daudi effects were induced by FCS and to higher extent by allospecific stimulation. Exposure to alloantigens induced allospecific cytotoxicity. Autologous PHA blasts were not affected. The results with the low density subset differed. Independently of the type of stimulus imposed, the low density fraction showed little if any proliferation, but its cytotoxic activity was stronger against all targets tested. In some of the experiments, anti-alloblast cytotoxicity was generated in the control cultures. Thus, polyclonal activation induced by FCS triggered in this fraction allospecific cytotoxicity. In this subset, the effect against allogeneic PHA blasts comprised a specific and a non-specific component because autologous PHA blasts were also lysed. Limiting dilution analysis involving allostimulation showed higher frequency of cytotoxic precursors in the low density subset. Split minicultures were tested for lysis of auto- and allogeneic blasts. Alloreactive cultures that did not lyse the autologous target were more frequent in the cultures initiated with the high density cells. There was no conclusive evidence for the existence of autoreactive cultures that did not lyse the allogeneic blasts.     

Development of patient derived organoids for cancer drug screening applications

Cancer is a disease characterised by abnormal cell growth that can invade or spread to other regions of the body. Organoids are three-dimensional ex vivo tissue cultures made from embryonic stem cells, induced pluripotent stem cells, progenitor cells or tissue that serve as a physiological model for cancer research. These are designed to recapitulate the in vivo properties of tumours. Importantly, effective recapitulation of the structure of tissues and function is believed to predict patient response, allowing for the creation of personalised therapy in a timely manner that may be used in the clinic. This Review discusses the pre-clinical model and different types of human organoids as models for the development of high throughput drug screening and also aims to highlight how organoids are shaping the future of cancer research.     

The thymus as primary site for antigen-specific T suppressor cells in neonatally induced tolerance to bovine serum albumin

The ontogeny of antigen-specific T suppressor cells in thymus and spleen was analyzed in CBA/Ca mice which were rendered tolerant as neonates by subimmunogenic doses of bovine serum albumin (low-zone tolerance). Activity of T suppressor cells from those mice was assessed by an assay in which spleen cells from animals primed with fluorescein-conjugated human gamma globulin can be stimulated in vitro to produce IgG anti-fluorescein antibodies when cultured in the presence of fluorescein-conjugated bovine serum albumin. Carrier-specific T suppressor cells appear first in the thymus (day 10), and much later (day 30) in the spleen. The data are discussed in connection with the possible role of T suppressor cells during induction of tolerance in newborn mice.     

Study of the HLA system in Burkitt's lymphoma

Seventy-eight patients with Burkitt's lymphoma and seventy controls from Ghana were typed for HLA-A, B, C and DR antigens, to determine whether there is an association between the HLA system and Burkitt's lymphoma. Increased relative risk was observed in Burkitt's lymphoma patients with DR7, HLA-A1 and B12 (BW44).     

3D facial morphometry in Italian patients affected by Aicardi syndrome

Aicardi syndrome (AIC) is a rare congenital neurodevelopmental disorder of unknown etiology, that affects almost exclusively females, originally characterized by corpus callosum agenesis, chorioretinal lacunae, and infantile spasms. The current diagnostic criteria also include qualitative facial features (prominent premaxilla, upturned nasal tip, decreased nasal bridge angle, sparse lateral eyebrows, and microphthalmia) that still need quantification. A three‐dimensional (3D) photogrammetric assessment of 11 Italian females, age 7–32 years, who satisfied AIC criteria, was performed. Linear distances and angles were computed from soft‐tissue facial landmarks coordinates. The z‐score values were calculated using data of 850 healthy reference females matched for age and compared by Mann–Whitney test (p < .01). Patients showed a shorter philtrum and right side orbital height (mean z‐scores: ?1.7, ?0.9), shorter superior, middle, and inferior facial depths (mean z‐scores: ?1.3, ?2.2, ?2.3), and a smaller length of mandibular ramus (mean z‐score: ?2.1); conversely, they showed larger nasal and lower facial widths, and lower facial convexity (mean z‐scores: 1.7, 1.4, 2.4). The inclinations of the orbit versus the true horizontal were increased bilaterally (mean z‐scores: 1.8, 1.1). Some common facial abnormalities were quantified in AIC patients using a noninvasive instrument. They may help clinicians in performing a definite AIC diagnosis in atypical or doubt cases.     

Xanthii Fructus Inhibits Inflammatory Responses in LPS-Stimulated Mouse Peritoneal Macrophages

Xanthii Fructus (XF) is an herb widely used in medicine for the treatment of a variety of inflammatory pathologies. In this study, using mouse peritoneal macrophages, we have examined whether XF affects nitric oxide (NO), tumor necrosis factor (TNF)-α, and interleukin (IL)-12p40 production induced by interferon (IFN)-γ and lipopolysaccharide (LPS). XF inhibits IFN-γ and LPS-induced NO production in a dose dependent manner. The decrease in NO synthesis was reflected as a decreased amount of inducible NO synthase protein. Furthermore, we also found that XF inhibits pro-inflammatory cytokine TNF-α production. However, treatment of XF in peritoneal macrophages had no effect on IL-12p40 production. These findings suggest that XF may be used in controlling macrophages-mediated inflammatory diseases.     

Involvement of E-cadherin and beta-catenin in germ cell tumours and in normal male fetal germ cell development

Intercellular contacts, mediated by E-cadherin, are essential for germ cell migration and maturation. Furthermore, it has been suggested that decrease or loss of E-cadherin correlates with tumour progression and invasive behaviour. beta-catenin is involved in a number of different processes, including cell--cell interaction when bound to cadherins, and determination of cell fate in pluripotent cells when activated via the Wnt signal-transduction pathway. To shed more light on the role of these factors in normal fetal germ cell development and the pathogenesis of germ cell tumours (GCTs), the present study investigated the presence and localization of E-cadherin and beta-catenin by immunohistochemistry. E-cadherin was only weakly expressed in or absent from fetal germ cells of the second and third trimesters, and was not expressed in carcinoma in situ/intratubular germ cell neoplasia unclassified (CIS/ITGCNU) and gonadoblastoma, the precursor of an invasive GCT in dysgenetic gonads. In GCTs, it was generally not expressed in seminoma and dysgerminoma, but was found in the vast majority of non-seminoma cells. beta-catenin was found in the cytoplasm of fetal germ cells at all gestational ages and in spermatogenesis in post-pubertal testes. It was also present in CIS/ITGCNU and gonadoblastoma. Whereas seminomas and dysgerminoma were negative, non-seminoma cells were frequently found to express beta-catenin. Expression of both factors therefore reflects the degree of differentiation of these tumours. No differences for either E-cadherin or beta-catenin were observed between samples of tumours resistant or sensitive to chemotherapy, and E-cadherin expression did not correlate with vascular invasion. E-cadherin and beta-catenin therefore play a role in both normal and malignant germ cell development and differentiation that warrants further investigation, but they seem to be of limited value as predictive or prognostic factors in GCTs.     

T cell receptor induced intracellular redistribution of type I protein kinase A

The productive activation of CD4(+) T lymphocytes, leading to proliferation and cytokine secretion, requires precise temporal regulation of intracellular cyclic AMP concentrations. The major effector molecule activated by cyclic AMP in mammalian cells is the cyclic AMP-dependent protein kinase A (PKA). The type I PKA isozyme mediates the inhibitory effects of cyclic AMP on T-cell activation. Using laser scanning confocal microscopy, we demonstrated that the regulation of PKA type I activity involves spatial redistribution of PKA type I molecules following T-cell receptor (TCR) stimulation. In resting T cells, PKA type I was located in membrane proximal regions and distributed equally across the cell. Shortly after antigen engagement, T cells and antigen-presenting cells formed an area of intense contact, known as the immunological synapse. TCR concentrated at the synapse, whereas PKA type I molecules redistributed to the opposite cell pole within 10 min after T-cell stimulation. Type I PKA redistribution was solely dependent on TCR signalling, because we observed the same temporal and spatial distribution after antibody-mediated cross-linking of the TCR-associated CD3 complex. Segregation of TCR and PKA type I molecules was maintained for at least 20 min. Thirty minutes after stimulation, PKA type I partially colocalized with the TCR. After 60 min, PKA type I distribution again approached the resting state. Considering that initial TCR signals lead to increases in intracellular cyclic AMP, PKA type I molecules may be targeted towards localized cyclic AMP accumulations or transported away from these areas, depending on the requirements of the cellular response.