Studies on the relationships between biotin and the behaviour of B and T lymphocytes in the guinea-pig

Summary In biotin-deficient guinea-pigs the number of circulating neutrophils is increased; lymphocytes carrying B and T markers are decreased. Incubation with biotin increases significantly the number of lymphocytes carrying B and T markers, from biotin-deficient guinea-pigs; no increase was observed when the lymphocytes from normal guinea-pigs were incubated.     

The value of good Biozzi antibody-producing strains of mice for the production of monoclonal antibodies]

We report here that using Biozzi's high and low responder strains of Mice in the preparation of monoclonal antibodies against human T lymphocytes, we observed with the high responder strain 1) a higher number of hybrids; 2) a huge increase in the proportion of hybrids secreting on antibody directed against human lymphocytes.     

Immunoglobulin synthesis by cord blood lymphocytes.

The IgG, IgA and IgM synthesis by adult peripheral blood and cord blood lymphocytes incubated alone and with pokeweed mitogen was quantitated. The cord blood lymphocytes produced no immunoglobulin even with mitogen stimulation while the adult peripheral blood lymphocytes responded to the mitogen with a significant (p less than 0.04) increase in immunoglobulin production.     

Immunoglobulin synthesis by cord blood lymphocytes

Summary The IgG, IgA and IgM synthesis by adult peripheral blood and cord blood lymphocytes incubated alone and with pokeweed mitogen was quantitated. The cord blood lymphocytes produced no immunoglobulin even with mitogen stimulation while the adult peripheral blood lymphocytes responded to the mitogen with a significant (p<0.04) increase in immunoglobulin production.     

Number of glucocorticoid receptors in lymphocytes and their sensitivity to hormone action

The study demonstrated a decreased level of glucocorticoid receptors (GR) in peripheral blood lymphocytes from hypercholesterolemic subjects, and an elevated level in patients with acute myocardial infarction. In the lymphocytes with a high GR number, dexamethasone inhibited [3H]-thymidine and [3H]-acetate incorporation into DNA and cholesterol, respectively, in the same manner as in the control cells. On the other hand, a decreased GR number resulted in a less efficient dexamethasone inhibition of the incorporation of labeled compounds. These data showed that the sensitivity of lymphocytes to glucocorticoids changed only with a decrease of GR level.     

A population of human lymphocytes staining for esterases.

A population of lymphocytes is found to stain positively for esterases. The positively staining lymphocytes are more predominant among T than B lymphocytes and are significantly increased on stimulation with PHA. Treatment with cholinestrase inhibitors reduces their number significantly.     

Kinetics of the appearance of HLA-DR antigens on human alloactivated T lymphocytes and the demonstration of new antigenic determinants

By studying serologically the appearance of HLA-DR determinants on T lymphocytes activated by a mixed lymphocyte culture, we have been able to demonstrate the existence of a new class of antigenic determinants distinct from classical HLA-DR antigens. Indeed, some monospecific anti-DR sera were cytotoxic from some alloactivated T cells, though not directed against their HLA-DR specificity. The absorption of these anti-sera on B lymphocytes bearing the HLA-DR antigen against which they were directed, did not remove their reactivity on alloactivated T lymphocytes. The absorption of the same anti-sera on activated T lymphocytes did not affect their anti-DR reactivity. This study shows the existence of new antigenic determinants expressed by T lymphocytes during their activation: alloactivated T lymphocyte antigens (AATL).     

A population of human lymphocytes staining for esterases

Summary A population of lymphocytes is found to stain positively for esterases. The positively staining lymphocytes are more predominant among T than B lymphocytes and are significantly increased on stimulation with PHA. Treatment with cholinestrase inhibitors reduces their number significantly.This work was supported by a grant from the Medical Research Council of Canada.     

Sur le rôle joué par l'atrophie du thymus dans l'inhibition de la lymphopoïèse provoquée par la carence alimentaire en protéines chez le rat mâle

Summary In protein-depleted rats, atrophy of the thymus is partially responsible for the quantitative reduction of medium and large blood lymphocytes which precedes the decrease in the number of small lymphocytes.On the other hand, during recovery from protein starvation the restoration of medium and large lymphocytes is much more pronounced in intact than in thymectomized rats.     

The binding of tritiated dexamethasone to lymphocytes of normal and leukemic subjects]

Specific binding sites for 3H-dexamethasone, possessing the characteristics of glucocorticoid receptors, were demonstrated in normal human circulating lymphocytes. The number of glucocorticoid receptors was found different from normal in half of the acute or chronic lymphoid leukaemias studied. A correlation between the number of glucocorticoid receptors and the therapeutical benefit of the glucocorticoid administration will be performed, including these preliminary observations.     

Röntgenbestrahlung und Hypothermie. Der Einfluss auf Körpergewicht,Hirngewicht, Kleinhirnentwicklung und Blutbild bei neugeborenen Hausmäusen

Summary New-born mice were X-rayed under extreme hypothermia in order to estimate the radioprotective effect of hypothermia on body weight, brain weight, development of cerebellum and the hematopoietic system. A protective effect was found in the rate of survival, in body and brain weight, in the cerebellum and in the number of erythrocytes. After hypothermia, the repair of damage in the cerebellum and the erythropoietic system starts earlier. The protected mature cerebellum shows an approximately normal status. Hypothermia does not prevent the initial decrease of lymphocytes caused by X-rays, and it produces a severe disturbance of hemoglobin content.     

Leukocyte mobilization from the guinea pig spleen by muscarinic cholinergic stimulation

Important interactions between the immune system and the nervous and endocrine systems have become increasingly accepted. The present results demonstrate that the cholinergic agonist carbacholine greatly increased the number of granulocytes and lymphocytes in the splenic venous blood, but not arterial blood, shortly after administration to guinea pigs. The effect was largely blocked by pretreatment with atropine. In contrast, animals treated with indomethacin had a decreased number of leukocytes in both splenic venous and arterial blood. A decrease in relative splenic weight due to carbacholine treatment was also blocked by atropine. However, cholinergic leukocyte mobilization, or that previously observed after adrenergic stimulation, may not be caused by capsule contraction since it is not accompanied by mobilization of erythrocytes. Furthermore, indomethacin, which potentiates the response of splenic smooth muscle to adrenergic stimuli, blocked the effect of noradrenaline (NA) on leukocyte mobilization.     

PD-L1在人子宫颈癌细胞异常表达并促T细胞凋亡

目的 探讨人子宫颈癌中负性协同刺激分子PD-L1的表达和它与肿瘤浸润淋巴细胞的关系以及PD-L1融合蛋白促宫颈癌患者外周血活化T细胞凋亡的作用.方法 采用免疫组化S-P法检测67例宫颈癌组织及20例正常宫颈组织中PD-L1的表达,分析PD-L1同临床病理特征的相关性,免疫荧光观察肿瘤浸润淋巴细胞数量,TUNEL法检测T细胞凋亡,体外实验将PD-L1融合蛋白细胞加入PHA刺激活化的宫颈癌患者外周血T细胞中共同培养,流式细胞术分析T细胞凋亡率和CD8+/CD4+T细胞比例.结论 正常子宫颈组织不表达PD-L1;宫颈癌组织中PD-L1的表达率为70％.宫颈癌PD-L1的表达与宫颈癌浸润深度相关(P＜0.05).PD-L1阳性病例肿瘤局部浸润淋巴细胞存在凋亡且CD8+T细胞数量明显减少;PD-L1融合蛋白组T细胞凋亡率明显高于抗PD-1组和空白对照组T细胞,分别为32.7％、18.3％和17.9％;CD8+T/CD4+T细胞的比值低于加入抗PD-1组和空白对照组,分别为0.864、0.894和0 907.结论 PD-L1在子宫颈癌中高表达且与肿瘤浸润程度及肿瘤浸润淋巴细胞数量减少有关,PD-L1能促进活化的T细胞尤其是CD8+T细胞的凋亡.     

Leukocyte mobilization from the guinea pig spleen by muscarinic cholinergic stimulation

Important interactions between the immune system and the nervous and endocrine systems have become increasingly accepted. The present results demonstrate that the cholinergic agonist carbacholine greatly increased the number of granulocytes and lymphocytes in the splenic venous blood, but not arterial blood, shortly after administration to guinea pigs. The effect was largely blocked by pretreatment with atropine. In contrast, animals treated with indomethacin had a decreased number of leukocytes in both splenic venous and arterial blood. A decrease in relative splenic weight due to carbacholine treatment was also blocked by atropine. However, cholinergic leukocyte mobilization, or that previously observed after adrenergic stimulation, may not be caused by capsule contraction since it is not accompanied by mobilization of erythrocytes. Furthermore, indomethacin, which potentiates the response of splenic smooth muscle to adrenergic stimuli, blocked the effect of noradrenaline (NA) on leukocyte mobilization.     

The environment in which lymphocytes differentiate influences their ability to cooperate in vivo.

Whether or not parental B lymphocytes cooperate with F1 T lymphocytes depends upon the environment in which parental bone marrow cells differentiate. Only those parental B lymphocytes that have differentiated in the F1 environment are able to cooperate with F1 T lymphocytes.     

Conséquences de la thymectomie sur la formule leucocytaire chez le cobaye

Summary In infantile guinea pigs, thymectomy determined a decrease of the leucocyte count in the circulating blood, resulting essentially from the decreased number of lymphocytes.Eosinophiles increased noticeably in the same animals.Thus the consequences of thymectomy were proved to be exactly opposite to those of administration of thymus extract as described in a previous publication.     

Protein kinase C-dependent NF-κB activation is altered in T cells by chronic stress

Chronic stress has been associated with impaired immune function. In this work we studied the effect of chronic mild stress (CMS) exposure on the early intracellular pathways involved in T cells after stimulation with mitogen. We found that mitogen stimulation of T lymphocytes from CMS-exposed mice resulted in a reduction of the intracellular [Ca²⁺] rise, an impairment of growth-promoting protein kinase C (PKC) activation, a lower NF-κB activation and an increase in the inhibitory cAMP-protein kinase A (PKA) pathway activity with respect to those found in control lymphocytes. However, T cell activation with the direct PKC activator phorbol 12-myristate 13-acetate plus calcium ionophore led to a similar proliferative response in both CMS and control lymphocytes, indicating that signals downstream of PKC would not be affected by stress. In summary, our results show that chronic stress induced an alteration in T cell early transduction signals that result in an impairment of the proliferative response.Received 11 February 2005; received after revision 20 May 2005; accepted 6 June 2005     

Somatic cell hybrids producing inhibitors of melanotic melanoma tyrosine hydroxylase

Summary Splenic lymphocytes from BALB/c mice pre-immunized with purified tyrosine hydroxylase (TH) were fused with murine myeloma N/1 cells. Supernatants of only 2 from large number of cloned cell hybrids contained an inhibitor of TH.     

Cyclin D3 and p53 mediate sulforaphane-induced cell cycle delay and apoptosis in non-transformed human T lymphocytes

Despite experimental evidence that sulforaphane can exert chemopreventive effects, whether these effects are specific for neoplastic cells is not known. Following our previous demonstration that sulforaphane induces cell cycle arrest and apoptosis in human T lymphoblastoid Jurkat leukemia cells and increases p53 and bax protein expression, we tested sulforaphane on non-transformed phytohemagglutinin-stimulated human lymphocytes. Here, we demonstrate that sulforaphane arrested cell cycle progression in G, phase, through a decrease in the protein expression of cyclin D3. Moreover, sulforaphane induced apoptosis (and also necrosis), mediated by an increase in the expression of p53. These findings suggest that sulforaphane is a growth modulator for T cells. Our in vitro evidence that sulforaphane is active and even cytotoxic in normal as well as transformed lymphocytes raises important questions regarding its suitability for cancer chemoprevention.     

K-Lymphocyte cytotoxicity: role of human blood group ABO, rhesus and P alloantibodies]

Using human erythrocytes of known antigenic density, sensitized by ABO and Rhesus (D) alloantibodies, it is shown that K cell cytotoxicity mediated by peripheral blood lymphocytes is directly correlated with the number of IgG molecules specifically bound to the target cell surface. The lytic sensitivity of P1k but not P2 or p erythrocytes coated with anti-Tja (anti-P + P1 + Pk) antibodies, demonstrates that effector K cells are mainly triggered through the IgG ANTI-Pk component of such sera.