IDEC-131 (Anti-CD154), Sirolimus and Donor-Specific Transfusion Facilitate Operational Tolerance in Non-Human Primates

CD154-specific antibody therapy prevents allograft rejection in many experimental transplant models. However, initial clinical transplant trials with anti-CD154 have been disappointing suggesting the need for as of yet undetermined adjuvant therapy. In rodents, donor antigen (e.g., a donor blood transfusion), or mTOR inhibition (e.g., sirolimus), enhances anti-CD154's efficacy. We performed renal transplants in major histocompatibility complex-(MHC) mismatched rhesus monkeys and treated recipients with combinations of the CD154-specific antibody IDEC-131, and/or sirolimus, and/or a pre-transplant donor-specific transfusion (DST). Therapy was withdrawn after 3 months. Triple therapy prevented rejection during therapy in all animals and led to operational tolerance in three of five animals including donor-specific skin graft acceptance in the two animals tested. IDEC-131, sirolimus and DST are highly effective in preventing renal allograft rejection in primates. This apparently clinically applicable regimen is promising for human renal transplant trials.     

BcL-2、Bax、CD44V6在乳腺癌表达及预后的研究

目的探讨影响乳腺癌患者预后的因素,协助临床制定手术方式及术后治疗方案。方法选择80例各型乳腺癌患者的标本,应用免疫组化SP方法,检测乳腺癌组织中癌基因BcL-2、Bax及黏附因子CD44V6的表达情况。结果乳腺癌中BcL-2、Bax及CD44V6的表达情况与肿瘤组织学分级、瘤体直径。有无转移及患者术后存活时间均有显著性相关(P<0.05或0.01)。结论BcL-2高表达、Bax低表达、CD44V6低表达的患者组织学分级好,肿瘤体积小,淋巴结转移少,术后存活时间长,这部分患者可做肿物扩大切除而保留乳房或即使已做乳房切除,术后也可减少放疗及化疗剂量。     

Surface activation markers of T lymphocytes: role in the detection of infection in neonates

Diagnosis of perinatal infection in the newborn is difficult; there may be few clinical signs and current tests are slow or non-specific. Detection of organisms, antigen or specific antibody to common pathogens often requires repeat samples and does not give immediate results. Haematological parameters, although relied upon frequently to diagnose infection in the neonate prior to a positive bacterial isolation, are unreliable and insensitive. Indicators such as an increase in neutrophil band cell counts are highly variable between morphologists. Infection induces the expression of a number of T lymphocyte surface markers, including CD45RA/CD45RO and CD45RO. The use of changed expression of surface markers as a laboratory test for detection of infection in neonates was evaluated. We used multiparameter flow cytometry to detect expression of early (CD45RA/CD45RO) and late (CD45RO) activation markers. In the respective groups of 50 full term (including 25 normal vaginal deliveries and 25 caesarean deliveries) and 30 premature, i.e. < 36 weeks gestation (born by either normal vaginal delivery or caesarean delivery) the CD45RA isoform was brightly expressed on newborn ‘naive’ CD4⁺ T cells, whereas the CD45RO isoform (including both ‘bright’ and ‘dim’ populations) was present on < 19% of CD4⁺ T cells from these newborn infants. In a group of 37 infants, tested to evaluate possible effects of non-infective parameters such as respiratory distress and iso-immunization, no significant changes in surface marker expression were found and specificity of the test was confirmed. In 14 neonates with documented sepsis, up-regulation of dual staining CD45RA/CD45RO isoforms on CD4⁺ T cells was detected early in the infection. In addition, we found that CD45RO expression persisted for several weeks after bacterial infection, and up to several months in viral infection. In conclusion, detection of T cell activation by flow cytometry for the early diagnosis of neonatal infection is an easy test to carry out on small volumes of blood, is inexpensive, and may be a specific indicator of infection.     

Chemical shift differences between free and Fab-bound peptide correlate with a two-stage selection of peptide sequences from a random phage display library to delineate critical and non-critical residues for antibody recognition

Epitope libraries provide a method to identify peptide ligands for antibodies, receptors or other binding proteins. As such, they provide a powerful tool to rapidly identify lead ligands in the drug discovery process. In an attempt to correlate structural information with the results from peptide screening, we have used NMR spectroscopy of peptide/antibody complexes to demonstrate that core residues identified through a two-stage selection process undergo a larger structural change upon binding antibody than do positions in the peptide amenable to a variety of side chains. The model system used was the M2 monoclonal antibody/Flag? octapeptide epitope system. We have analyzed two peptides: Ac-Asp-Tyr-Lys-Leu-Gly-Asp-Asp-Leu-NH₂ (peptide l), which contains several non-core positions randomized, and Ac-Asp-Tyr-Lys-Asp-Asp-Asp-Asp-Leu-NH₂ (peptide 2), which closely corresponds to the original Flag? sequence. Enrichment of the peptides with ¹⁵N facilitated the investigation by permitting spectral editing of the peptide resonances in the presence of antibody. For peptide 1 the absolute shifts for the free vs. Fab-bound peptide were found to be largest for the amide groups of Asp-1 and Asp-6, in agreement with classification of these residues as critical by the phage display library selection process. For peptide 2 the largest absolute shifts were observed for Asp-1 and Asp-4, with the other aspartic acid residues also showing significant but smaller changes. © Munksgaard 1995.     

Immunoreactivity of sinusoids in hepatoblastoma: an immunohistochemical study using lectin UEA-1 and antibodies against endothelium-associated antigens, including CD34

Sinusoids are found not only in the normal liver but also in certain liver tumours, including hepatoblastoma, the most common malignant liver tumour in childhood. In this study, sinusoids in 12 hepatoblastomas, of various subtypes, and in normal liver were investigated with UEA-1 and antibodies against von Willebrand's factor, CD31 and CD34 to detect differences of possible diagnostic significance. In the normal liver, staining of sinusoids was seen with all these markers, but it was focal and confined to a few sinusoids near the portal tracts. In hepatoblastoma, the endothelial markers reacted with the sinusoids to varying extents. UEA-1 and anti-CD34 usually stained the majority of these vessels, anti-CD34 staining greater numbers of sinusoids and with greater intensity. Immunostaining revealed that both number and spatial organization of sinusoids in hepatoblastoma are dependent on the subtype. In addition to staining of endothelium, one of the two small cell hepatoblastomas exhibited strong immunoreactivity of the tumour cells for CD34. These findings show that the marked difference in sinusoidal immunoreactivity for CD34 between normal liver and hepatoblastoma could be useful for discriminating between non-neoplastic liver tissue and highly differentiated fetal hepatoblastoma. Our findings also show that small cell hepatoblastoma, in addition to acute leukaemia, should be considered when immunoreactivity for CD34 is found in small round and blue cell tumours in childhood.     

Reizhusten, Belastungsdyspnoe und zystische Lungenveränderungen bei einem 28jährigen Patienten

Zusammenfassung Eine neu aufgetretene Dyspnoesymptomatik und eine symmetrische, apikal betonte retikulonodul?re Zeichnungsvermehrung im R?ntgen-Thorax bei jungen rauchenden Erwachsenen müssen an das seltene Krankheitsbild der pulmonalen Histiocytosis X denken lassen. Klinischer Befund, laborchemische- und Lungenfunktionsuntersuchungen zeigen unspezifische Befunde. Neue radiologische Verfahren wie die hochaufl?sende Computertomographie (HRCT) leisten bei gezielter Indikationsstellung eine entscheidende differentialdiagnostische Hilfestellung. Dieser Fall verdeutlicht die M?glichkeit einer Diagnosesicherung durch transbronchiale Biopsien unter Verzicht auf offene Lungenbiopsien. Eine ambulante Diagnostik war m?glich, das h?here Risiko eines operativen Eingriffes konnte vermieden werden. Die Indikation zur Therapie ist nicht gesichert und wird daher durch den Grad der subjektiven bzw. funktionellen Einschr?nkung sowie den Verlauf bestimmt.     

High levels of the soluble form of CD30 molecule in rheumatoid arthritis (RA) are expression of CD30+ T cell involvement in the inflamed joints.

The CD30 is a surface molecule expressed by Th2-type lymphokine-producing T cells upon activation. CD30-expressing activated T cells release a soluble form of the molecule, which can be detectable both in vitro and in vivo. In the present study, high levels of soluble CD30 were found in peripheral blood and synovial fluid from patients with RA. However, CD30+ CD3+ cells, either CD4+ or CD8+, were significantly present in synovial fluid, but not in peripheral blood, of RA patients. Serum values of soluble CD30 were higher in active than inactive RA patients and directly correlated with rheumatoid factor serum titres. These data strongly support an involvement of CD30+ T cells in the immune processes of rheumatoid synovitis, and may suggest a relationship between Th2-type cytokine-secreting T cells and the pathological response in RA.     

In vivo induction of CD4+ T cell responses by antigens covalently linked to synthetic microspheres does not require adjuvant

Macrophages, dendritic cells or B lymphocytes have been shownto play a major role in the presentation of soluble antigensto CD4⁺ T cells. In contrast, the capacity of these cells topresent particulate antigens such as bacterial or parasiticantigens to T cells remains controversial. To investigate thisquestion, well defined particulate antigens were prepared bycovalent linkage of proteins or peptides to 1 µm in diametersynthetic microspheres. The T cell immunogenicity of such particulateantigens was analyzed in vitro and in vivo. In vitro, a solubleprotein such as hen egg lysozyme (HEL) coupled to beads stimulateda strong proliferative T cell response of lymph node cells fromHEL-primed mice or of specific T cell hybridomas. HEL coupledto beads was presented to the specific T cell hybridomas bysplenocytes or by peritoneal macrophages, but not by lymphomaB cells. Immunization of mice with several different proteinantigens or with a synthetic peptide covalently linked to beadsinduced strong CD4⁺ T cell responses in the absence of adjuvant.The strong in vivo immunogenicity of proteins coupled to beadsdid not result from a non-specific adjuvant effect of beadssince covalent linkage of the antigen to beads was strictlyrequired to induce T cell responses in the absence of adjuvant.In vivo treatment by carrageenan showed that macrophages arerequired for the in vivo stimulation of T cell responses bythese particulate antigens. Thus, these results demonstratedthe role of phagocytic cells, especially macrophages, for invivo presentation of particulate antigens. These particulateantigens represent an interesting approach for the developmentof new vaccines, and for the in vivo analysis of the role ofvarious antigen presenting cells in T cell activation and differentiation.     

Elevation of plasma thioredoxin levels in HIV-infected individuals

Thioredoxin (Trx), a ubiquitous protein intimately involvedin redox and protein disulfide reductions, has been shown tobe released from cells and to have cytokine-like activities.In addition, Trx has been implicated in the redox regulationof immunological responses and shown to be deficient in tissuesfrom AIDS patients. In studies presented here, plasma Trx levelswere measured by ELISA in plasma samples from HIV-infected individuals(n = 136) and HIV-negative controls (n = 47). To account forthe release of Trx into plasma due to hemolysis, the Trx measurementswere corrected according to the level of hemoglobin in the plasmasample. Data presented show that, in contrast to tissue Trxlevels, corrected plasma Trx levels are significantly higherin HIV-infected individuals than in controls (P < 0.0001).Furthermore, {small tilde}25% of the HIV-infected individualsstudied have plasma Trx levels greater than the highest levelfound in controls (37 ng/ml). Detailed multiparameter FACS analysisof peripheral blood mononuclear cells (PBMC) from the infectedindividuals demonstrates that those with higher plasma Trx levels(37 ng/ml or greater) tend to have lower overall CD4 counts.In addition, increases in plasma Trx levels correlate with decreasesin monochlorobimane staining (indicative of lower intracellularglutathione levels in PBMC) and with changes in surface antigenexpression (CD62L, CD38 and CD20) that occur in the later stagesof HIV infection. These correlations suggest that elevationof plasma Trx levels may be an important component of advancedHIV disease, perhaps related to the oxidative stress that oftenoccurs at this stage.