Depressed immune functions in the early phase of varicella-zoster virus reactivation

Severe combined immune deficient (SCID) mice inoculated intravenously with vaccinia virus (VV) became sick within 6–8 days and died 10–12 days after infection. Tail lesions developed and the number depended on the virus inoculum. Age-matched immunocompetent NMRI mice similarly infected also developed tail lesions but did not become sick. When the infected SCID mice were treated with the acyclic nucleoside phosphonate HPMPC [(S)-1-(3-hydroxy-2-phosphonylmethoxypropyl) cytosine], either for 5 consecutive days starting on the day of infection or for 5 consecutive days starting on day 2, 4, or 6 post infection, or as a single dose at 7 days or 1 day before infection, VV-associated death was significantly delayed. VV-infected SCID mice that received two doses of 20 mg/kg of HPMPC every week survived the infection for about 130 days. The period during which the mice remained disease-free following HPMPC treatment correlated with the absence of detectable virus in their organs. The VV/SCID mouse model employed here may be useful for determining whether (attenuated) recombinant VV (carrying HIV genes) may have detrimental effects in the immunodeficient host. HPMPC may be considered as a drug candidate for the treatment and prophylaxis of such complications.     

Possible contribution of circulating transforming growth factor‐β1 to immunity and prognosis in unresectable hepatocellular carcinoma

Transforming growth factor‐β1 (TGF‐β1) has been implicated in tumor progression. The relationship of this cytokine as measured in plasma to anti‐tumor immunity and prognosis was investigated. This study consisted of 70 consecutive patients with unresectable hepatocellular carcinoma (HCC) (median age, 65 years). Forty‐four healthy age‐matched subjects and 32 patients with cirrhosis but no carcinoma served as controls. Patients with HCC were divided into those with plasma TGF‐β1 concentrations above (group A, n=21) or below (group B, n=49) 10 ng/ml (the mean concentration+2SD in the concentrations of the controls with cirrhosis was 8.7 ng/ml). Age, gender, Child‐Pugh grade, and tumor stage distributions were similar in groups A and B. Considering all tumor stages together and individually, group A had a significantly shorter survival (median for all stages, 2 months) than group B (median for all stages, 10 months; P<0.01, generalized Wilcoxon's test). Groups A and B had significantly shorter survival than controls with cirrhosis (P<0.001 for each). Lymphokine‐activated killer (LAK) activity in group A was significantly lower than that in group B (P<0.001). Natural killer (NK) activity in group A was also significantly lower than that in group B (P<0.05). Plasma TGF‐β1 concentration was a significant predictor of survival by Cox's proportional‐hazards regression analysis (multivariate analysis, P<0.01). LAK and NK activities were also weak but significant predictors (P<0.05 and <0.05, respectively). These data suggest that plasma TGF‐β1 concentration is a predictor of outcome of patients with unresectable HCC. Circulating TGF‐β1 supposedly contributes to the suppression of anti‐tumor immunity in the advanced disease.     

Antilymphocyte immunoglobulins stimulate peripheral blood lymphocytes to proliferate and release lymphokines

Five different preparations of antilymphocyte immunoglobulins (ATG) and antithymocyte immunoglobulins (ALG) with good or little clinical response were compared for their hematopoietic and immunological activities. All ATG/ALG lots demonstrated complement-mediated cytotoxicity on peripheral blood mononuclear cells. They had different titers of antibody specificities against lymphocyte cell membrane antigens. Neither clinically effective nor ineffective lots demonstrated any apparent colony stimulating activity on bone marrow mononuclear cells. Purified Natural Killer cells failed to be stimulated by ATG/ALG in liquid culture. ATG/ALG demonstrated potent T-cell stimulating activity comparable to phytohemagglutinin. This stimulation was blocked by anti-IL-2 receptor monoclonal antibodies, and was inhibited dose-dependently by cyclosporin-A. Some clinically ineffective ATG/ALG lots also stimulated T cells to release lymphokines. The differences in these characteristics among ATG/ALG lots provide some clues to guide further efforts to elucidate a key mechanism of therapeutic effectiveness.     

人脑海马内部微血管三维构筑的研究

本文收集广州地区６个月胎儿至６岁儿童新鲜大脑标本６３例（１２６侧），其中５例作脑血管有机玻璃单体铸型，３５例用碱性磷酸酶染色（包括７例墨汁灌注后复染），其余用于墨汁灌注法，在光镜暗视野全景放大观察和日立Ｓ－４５０扫描电镜观察，较完整地显示人脑海马内部血管动脉－微动脉－毛细血管前括约肌－毛细血管－微静脉－小静脉连续性立体构筑。此外还观察到微血管形态特征及微血管间存在多种吻合。     

两种免疫调节剂辅助LAK细胞杀伤喉癌细胞的体外研究

为探讨如何提高白细胞介素－２（ＩＬ－２）／ＬＡＫ细胞过继免疫治疗的抗肿瘤作用，应用免疫调节剂分枝杆菌多糖（Ｍｙｃｏｂａｃｔｅｒｉａｌｐｏｌｙｓａｃｃｈａｒｉｄｅｓ，ＭＰＳ）或ＣＤ３单克隆抗体协同ＩＬ－２诱导的健康人外周血淋巴细胞来源的ＬＡＫ细胞在体外扩增，测定其对喉癌ＨＥＰ－２细胞杀伤活性。实验结果：①不同免疫调节剂对ＬＡＫ细胞扩增的影响：实验组三组细胞于体外扩增均明显高于对照组（Ｐ＜０．０１）；ＭＰＳ组或ＣＤ３组细胞的扩增倍数比单纯应用ＩＬ－２组为高（Ｐ＜０．０１）；其中扩增倍数最高者为ＭＰＳ组，与ＣＤ３组相比，Ｐ＜０．０５。②不同免疫调节剂诱导的ＬＡＫ细胞对喉癌ＨＥＰ－２细胞的杀伤活性比较：在培养一周时，实验组三组对ＨＥＰ－２细胞的杀伤活性均高于对照组，以ＣＤ３组及ＭＰＳ组杀伤活性最高，其杀伤活性均为５５．５％；于培养第二周，ＣＤ３组杀伤ＨＥＰ－２细胞活性仍较高，其他实验组细胞杀伤活性均明显下降。结论：免疫调节剂ＭＰＳ和ＣＤ３单克隆抗体均可通过增强ＬＡＫ细胞体外增殖和杀瘤活性而提高肿瘤过继免疫治疗效果。     

Altered Th1/Th2 commitment in human CD4+ T cells with ageing

The human immune system undergoes continuous remodelling with the advancement of age. Since age-associated functional alterations in the immune system could be caused by a possible change in helper T cell regulation in elderly subjects, we comparatively studied the function of CD4+ T cells in peripheral blood obtained from both young and old healthy volunteers. Upon cell activation by phorbol myristate acetate and ionomycin, the proportion of CD4+ T cells containing interferon-gamma (IFN-gamma) was found to be greater in the old subjects. Utilizing a co-culture system, which activated CD4+ T cells via the TCR/CD3 complex and CD28, we found that CD4+ T cells from the old subjects secreted more IFN-gamma and IL-2, but less IL-4, than those from the young subjects. Upon cell activation by co-culture, CD4+ T cells from the old subjects expressed more CD26, CD40L, and LFA-1, but less CD30, than those from the young. These results together suggest that the microenvironment in which CD4+ T cells develop in older people may cause production of more cells committed to Th1 than that in younger subjects.     

Antigen presenting cell-derived co-stimulatory signals can selectively regulate IL-2 and IL-4 production from a Th0 cell hybridoma

T_h0 cells are a subpopulatlon of T_h cells that produce bothIL-2 and IL-4. In order to study the selective regulation oflymphokines in T_h0 cells, a T_h0 cell hybridoma, GA15, was generatedby fusing a T_h2 clone with the thymoma BW5147. The pattern oflymphokines secreted by GA15 was found to depend on the antigenpresenting cells (APC) used for stimulation. When GA15 was stimulatedwith antigen and splenocytes, both IL-2 and IL-4 were produced.However, when the B cell hybridoma LB was used as APC, onlyIL-2 was detected. Although LB cells could not stimulate IL-4production, they were more potent than were spleen cells atinducing IL-2 production, demonstrating that the differencebetween the two APC populations was qualitative rather thanquantitative. Similar results were seen upon stimulation withconcanavalin A or anti-CD3 mAb. Regulation of interferon- productionparalleled regulation of IL-4 production. The failure of LBcells to stimulate IL-4 production was not due to inhibitionor consumption of IL-4 and the activity could not be restoredby adding IL-1, spleen cell supernatants or spleen cells lackingthe appropriate MHC molecule. Finally, the parent T_h2 cloneused in the fusion showed a similar inability to produce IL-4in response to LB cells. These data indicate that APC-derivedco-stimulatory signals can selectively affect IL-2 and IL-4production in a T_h0 cell hybridoma. Therefore, the choice ofAPC may lead to selective stimulation of particular lymphokinesby acting on T_h0 cells.     

Microassay for photometric quantitation of macrophage mediated tumor cytotoxicity using an automated densitometer

A simple and reproducible microassay for the quantitation of macrophage mediated cytotoxicity is described. The method is based on the measurement of absorbance at 630 nm of residual Giemsa stained target cells and effector macrophages using an automated densitometer. Applying this novel method, it was possible to demonstrate time dependent growth characteristics of C3H/MCA and BHK/Py target cell lines. Using C3HeB/FeJ or C3H/HeJ murine effector macrophages and syngeneic transformed fibroblast target cells (C3H/MCA or 3T12), the method was further applied to demonstrate: (1) dose related activation of macrophages by lipopolysaccharide (LPS) and by macrophage activating factor (MAF); (2) synergistic augmentation of MAF-mediated macrophage cytotoxicity by LPS; (3) unresponsiveness of C3H/HeJ macrophages to LPS; and (4) increased cytotoxicity with increasing effector: target cell ratios. Guinea pig peritoneal macrophages were also shown to produce enhanced LPS or MAF-mediated cytotoxicity for C3H/MCA or BHK/Py target cells. The novel method was shown to compare favorably with results obtained by cytotoxic release of [3H]thymidine from prelabeled target cells. The advantages of the method are: (1) the elimination of the need for radioactive materials; (2) the ability to perform quantitation directly in microtiter plates; (3) the relative ease and rapidity in which experiments may be performed and quantitated; (4) its sensitivity and reproducibility; and (5) the ability to simultaneously quantitate and observe the biological events either microscopically or macroscopically.     

A reappraisal of the macrophage electrophoretic mobility (MEM) test for the measurement of lymphokine activity

Using a cell electrophoretic apparatus, which was sensitive in detecting small changes in electrophoretic mobility (EPM), the macrophage electrophoretic mobility (MEM) test was investigated as a routine method for detecting lymphokine activity. Electrophoretic analysis of guinea-pig macrophages revealed 2 main subpopulations, one with an EPM of 0.90 micron cm s-1 V-1 (fast) and the other, an EPM of 0.83 micron cm s-1 V-1 (slow). From 23 experiments the fast and slow populations were found to consist of 90% and 10% cells, respectively. When macrophages were incubated with standard guinea-pig lymphokine preparations there was a significant decrease in the fast population with a corresponding increase in the slow population. This lymphokine induced 'slowing' of the macrophages was shown to be very reproducible. Since only 50% of macrophages of high EPM were observed to respond to lymphokine activity, it is not surprising that the MEM test has failed in the past when investigators have accepted as significant a 10-15% reduction in EPM, estimated from measurements made on only 10 macrophages. Parallel bioassays indicated that there were appreciable potency differences for macrophage slowing factor (MSF) and macrophage migration inhibition factor (MIF) activities in the lymphokine preparations used which suggest that these activities may be due to different molecular entities.     

Schistosoma mansoni: cell-mediated immunity evaluated by antigen-induced leukocyte adherence inhibition assay

Peripheral blood leukocytes (PBL) from schistosomiasis patients fail to adhere to glass in the presence of soluble egg antigens (SEA) or soluble worm adult antigenic preparation (SWAP). These leukocytes are non-reactive with S. mansoni unrelated antigens (C. albicans and bovine albumin). Supernatants obtained from cultures of mononuclear cells of patients with antigens were able to inhibit granulocyte adherence to glass. The inhibition of antigen-induced adherence (LAI assay) was not observed when PBL or supernatants were obtained from normal subjects or from schistosomiasis patients after chemotherapy. These results show that under the conditions tested, leukocytes appear to react directly with SEA or SWAP thus losing their property of adherence to glass.