Phenotypical and functional evaluation of CD8+/S6F1+ T lymphocytes in haemophiliac individuals with HIV-1 infection.

In this study we investigated the distribution of the S6F1 antigen, an epitope of the lymphocyte function-associated antigen, on CD8+ T lymphocytes in a series of 15 HIV-1+ and 20 HIV-1- haemophiliac patients. MoAbs recognizing the S6F1 antigen have been claimed to distinguish between killer effectors (brightly S6F1+ stained) and suppressor cells (dimly S6F1+ stained) within the CD8+ lymphoid population. In addition, we tried to find a correlation between the spontaneous in vitro immunoglobulin synthesis from patients' peripheral blood lymphocytes and the pattern of S6F1 expression. Although the total number of double-positive CD8+/S6F1+ cells was similar in both HIV-1+ and HIV-1- haemophiliac patients, a significant increase in the CD8+/S6F1+ population bright versus dim was documented in HIV-1-infected with respect to HIV-1- haemophiliacs (bright/dim ratio 3.97 +/- 0.61 versus 0.75 +/- 0.1, respectively, P < 0.005). This finding was correlated to a significant increase in spontaneous in vitro immunoglobulin production in HIV-1+ subjects compared with control haemophiliacs (P < 0.005). Purified CD8+ lymphocytes from HIV-1+ subjects showed a reduced suppressor activity on mitogen-induced immunoglobulin production. Taken together, these data suggest that HIV-1 infection favours the generation of CD8+/S6F1+ bright cells with putative cytotoxic-associated function, leading to a progressive reduction in the number of CD8+/S6F1+ dim suppressor lymphocytes. This phenomenon may contribute to the polyclonal hypergammaglobulinaemia present in HIV-1+ haemophiliac patients.     

Biological consequences of the heterogeneous irradiation of lymphocytes during technetium-99m hexamethylpropylene amine oxime white blood cell labelling

Technetium-99m hexamethylpropylene amine oxime (^99mTc-HMPAO) labelling of white blood cells, routinely used for the detection of infection, results in the incorporation of radioactivity by polymorphonuclear leucocytes and also lymphocytes and can induce cell lesions in the latter case. The aim of this study was therefore to acquire data on the morphological and functional status of labelled lymphocytes present in the ^99mTc-HMPAO leucocyte mixture and to determine the cellular consequences of labelling. The mean radioactivity associated with lymphocytes was 325±10.8 kBq/10⁶ lymphocytes under standard labelling conditions. Microautoradiographic studies showed that labelling was heterogeneous (4% intensely labelled cells), which prevented calculation of the mean absorbed dose. The frequency of chromosomal aberrations (dicentrics and rings) in the labelled lymphocytes for 380 kBq/10⁶ cells was 1.08±0.09 but no abnormality was observed in the unlabelled control lymphocytes. The plating efficiency of labelled lymphocytes was reduced, as compared with that for control cells, but some lymphocytes were still able to form clones and were still ”alive” by radiobiological definition. It is therefore suggested that lymphocytes should be removed from ^99mTc-HMPAO cell preparations before administration to patients. Received 9 March and in revised form 1 June 1998     

Functional relevance during lymphocyte migration and cellular localization of activated β1 integrins

The state of integrin activation can be assessed by monoclonal antibodies (mAb) that selectively recognize integrins in their active form. We demonstrate herein that the expression of the epitope recognized by mAb HUTS-21 is induced on T lymphoblasts upon binding of soluble vascular cell adhesion molecule (VCAM)-1 and an 80-kDa tryptic fragment of fibronectin (FN80) to the β1 integrins very late activation antigen (VLA)-4 and VLA-5, and that this effect is dependent on ligand concentration and is specific for β1 integrins. On T lymphoblasts adhering to immobilized fibronectin, the HUTS-21 epitope localized exclusively to sites of integrin binding to fibronectin. These results indicate that mAb HUTS-21 recognizes a ligand-induced binding site (LIBS) on the common β1 subunit of VLA proteins. Engagement of β1 integrins through this LIBS epitope inhibited T lym-phoblast movement on fibronectin, as determined by quantitative time-lapse video microscopy studies. Furthermore, the HUTS-21 mAb also prevented T lymphoblast-directed migration through gradients of substratum-immobilized β1 integrin ligands such as fibronectin or VCAM-1, whereas it did not affect migration on intercellular adhesion molecule (ICAM)-1. This anti-LIBS mAb stimulated cell adhesion through postreceptor events, without affecting receptor affinity for ligand, and appears to interfere with cell migration by a mechanism distinct from that of other anti-β1 activating antibodies.     

葫芦素B对小鼠的免疫增强作用

葫芦素B（CuB）是中药甜瓜蒂的主要成分，为四环三萜类物质。葫芦素B0.1mg/kg即能提高小鼠外周血液T淋巴细胞数；0.2mg/kg能提高PHA诱导的T淋巴细胞转化率和脾脏空斑形成细胞数；0.4mg/kg时血清溶血素水平也明显增加。较大剂量（0.8mg/kg）时碳粒廓清率及腹腔巨噬细胞吞噬率显著提高。结果表明：葫芦素B能增强整个免疫系统功能，对细胞免疫的作用最强，对体液免疫也有较强作用。     

Amplification of extrachromosomal small circular DNAs in a murine model of accelerated senescence. A brief note

Extrachromosomal circular DNA complexes from peripheral blood lymphocytes from inbred mice of accelerated senescence, were detected by mica-press-adsorption method. In senescence-resistant series (SAM-R), polydisperse circular DNAs were observed at 7 weeks of age and a restricted size class of small circular forms of 0.4-0.8 microns in contour length was amplified several-fold at 26 months of age. In senescence-prone series (SAM-P), a similar amplification of small circular DNAs was observed at young age of 10 weeks and more progressive at 17 months of age.     

The use of lymphocyte phosphoglucomutase as a genetic marker in bone marrow transplant recipients

Summary Lymphocyte phosphoglucomutase can be used as a genetic marker to document successful engraftment in bone marrow transplant recipients. Two patients who underwent marrow transplantation as a treatment for acute leukemia showed a change into donor-type isozyme pattern.     

Lymphocyte transformation in the presence of myelin basic protein in multiple sclerosis and control subjects

The transformation of lymphocytes in vitro in the presence of human myelin basic protein has been investigated in normal people, patients with multiple sclerosis (MS) and controls with other neurological diseases. There was little or no response at low concentrations (1--10 microgram/ml) but significant transformation at higher concentrations (100--1000 microgram/ml) in all three groups. There was no significant difference among the groups as a whole, but those MS patients who had had disease for more than 10 years did show greater responses than normal subjects (P less than 0.05). Increased responses could not be correlated with any other aspect of disease activity: in particular they were not increased in patients with acute relapses. The use of autologous serum instead of homologous AB Rhesus positive serum did not significantly alter lymphocyte responsiveness. The absence of any response in the presence of purified calf thymus histone suggests that the response to myelin basic protein indicates a low level of lymphocyte sensitization to this antigen even in normal subjects. The present evidence does not support a primary pathogenetic role for such a reaction in MS. The increased response in patients with a long duration of disease might merely be an effect of white matter damage or might represent an amplification of the normal immune response contributing to myelin breakdown and leading to the emergence of the progressive stage of the disease. The study of lymphocyte responsiveness over a wide range of concentrations of myelin basic protein is considered to resolve some of the controversy surrounding this subject in the literature.     

Analysis of CD27 surface expression on T cell subsets in MS patients and control individuals

Within the peripheral blood, CD4⁺CD27⁻ T cells only reside within the CD45RAT ⁻(memory or primed) T cell subset. Cells with this phenotype have characteristics of specialized effector T cells according to their cytokine secretion profiles and the expression of tissue-specific adhesion molecules. This subset was previously found to be increased in certain diseases that are associated with immune activation. Therefore we analyzed CD27 expression of peripheral blood and CSF T cells in MS patients. Within the CD4⁺ T cell subset no differences were seen between MS patients and controls in proportions of CD45RA⁻CD27⁻ cells. However, when the CD3⁺ T cell compartment was analyzed, CD27⁻ cells were also found within the CD45RA⁺ subset. These cells, most likely CD8⁺, are significantly reduced in PBL and CSF of MS patients as compared with OND patients. In MS and OND groups the level of CD27⁻ cells in peripheral blood correlated significantly with that in CSF, indicating a balanced migration of CD27⁻ cells between the two compartments. In OIND patients, however, this equilibrium was lost. The correlation of the level of CD27⁺ cells with the amount of intrathecally produced IgG in MS patients may suggest that CD27⁺ cells are responsible for B cell help in this disease.     

Lymphocyte subsets alteration in patients with argentine hemorrhagic fever

Peripheral blood lymphocyte subpopulations were studied in 15 patients with Argentine Hemorrhagic Fever (AHF), during the acute period of the disease and in early convalescence. Anti-human Ig antibodies were used to identify B cells and monoclonal antibodies to assess T4 and T8 subsets. During the acute period of the disease, significant alterations were found in B, T4, and T8 lymphocytes (P less than .001), as well as in T4/T8 ratios (P less than .001). These abnormalities disappeared in early convalescence, around 30 days after the clinical onset. Diminished numbers of T4 lymphocytes are interpreted as relevant to the immunodepression that characterizes the acute phase of AHF.     

梅毒血浆反应素快速试验持续阳性患者外周血淋巴细胞亚群的检测及其临床意义

目的观察经驱梅治疗后梅毒血浆反应素快速试验(RPR)持续阳性且仍具传染性的隐性梅毒患者外周血淋巴细胞亚群的变化。方法应用流式细胞仪检测43例隐性梅毒患者外周血T淋巴细胞亚群及NK淋巴细胞,并与30例健康人对照。结果(1)本组隐性梅毒患者外周血CD3、CD4及NK淋巴细胞的测定结果与对照组无显著差异(P>0.05),而CD8显著升高(P<0.05)。(2)经过驱梅治疗但RPR持续阳性两年内的患者CD3、CD4及CD8淋巴细胞数显著高于对照组(P<0.05),NK淋巴细胞显著低于对照组(P<0.05);两年以上的患者CD3、CD4及CD8淋巴细胞数与对照组无显著差异(P>0.05),但NK淋巴细胞显著高于对照组(P<0.05)。(3)两年内者CD3、CD4淋巴细胞数高于、而NK淋巴细胞低于两年以上者(P<0.05);两组CD8淋巴细胞相比差异无显著性(P>0.05)。结论经过驱梅治疗但RPR持续阳性且仍具传染性的隐性梅毒患者存在细胞免疫不平衡和免疫抑制,这种免疫不平衡和抑制可能降低机体抵抗和清除梅毒螺旋体感染的能力,并且与梅毒患者治疗困难,RPR持续阳性有关。