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Extracellular vesicles (EVs) are nanosized vesicles with a lipid bilayer that are released from cells of the cardiovascular system, and are considered important mediators of intercellular and extracellular communications. Two types of EVs of particular interest are exosomes and microvesicles, which have been identified in all tissue and body fluids and carry a variety of molecules including RNAs, proteins, and lipids. EVs have potential for use in the diagnosis and prognosis of cardiovascular diseases and as new therapeutic agents, particularly in the setting of myocardial infarction and heart failure. Despite their promise, technical challenges related to their small size make it challenging to accurately identify and characterize them, and to study EV-mediated processes. Here, we aim to provide the reader with an overview of the techniques and technologies available for the separation and characterization of EVs from different sources. Methods for determining the protein, RNA, and lipid content of EVs are discussed. The aim of this document is to provide guidance on critical methodological issues and highlight key points for consideration for the investigation of EVs in cardiovascular studies. [ABSTRACT FROM AUTHOR]

Cell manufacturing facilities need to define the potency of mesenchymal stromal cells (MSCs) as cellular therapeutics in advanced clinical trials or marketing approval. Since MSCs' mechanism of action in humans is not well defined, more than a single functional property of MSCs needs to be captured as a surrogate measure of potency utilizing assay matrix technologies. However, the current limitation is the sole investigation of MSC-mediated T-cell suppression as a surrogate measure of potency. We investigated the effect of MSCs on B-cell matrix responses to be incorporated into the assay matrix potency analytical system. Our results demonstrate that MSCs inhibit B-cell differentiation and block pan-antibody secretion upon activation of B cells in the PBMCs. In contrast, MSCs are inferior in blocking B-cell matrix responses when purified B cells are used. Mechanistic analysis has demonstrated that MSC-mediated inhibition of B-cell matrix responses is non-contact dependent and Tryptophan metabolic pathway plays a major role, akin to the mechanism of MSC-mediated T-cell suppression. MSCs also inhibit both T-cell and B-cell responses when both of these lymphoid populations are concurrently activated in the PBMCs. Secretome analysis of MSC and T/B cell-activated PBMC cocultures identified direct and inverse correlative matrix signatures between humoral antibody isotypes and secretory molecules. The current analysis of the combined and concomitant investigation of T-cell and B-cell matrix responses fulfills the potency assay matrix strategy by incorporating MSCs' interaction with more than a single inflammatory immune responder. Graphical Abstract [ABSTRACT FROM AUTHOR]

Great expectations have been set around the clinical potential of regenerative and reparative medicine in the treatment of cardiovascular diseases [i.e. in particular, heart failure (HF)]. Initial excitement, spurred by encouraging preclinical data, resulted in a rapid translation into clinical research. The sobering outcome of the resulting clinical trials suggests that preclinical testing may have been insufficient to predict clinical outcome. A number of barriers for clinical translation include the inherent variability of the biological products and difficulties to develop potency and quality assays, insufficient rigour of the preclinical research and reproducibility of the results, manufacturing challenges, and scientific irregularities reported in the last years. The failure to achieve clinical success led to an increased scrutiny and scepticism as to the clinical readiness of stem cells and gene therapy products among clinicians, industry stakeholders, and funding bodies. The present impasse has attracted the attention of some of the most active research groups in the field, which were then summoned to analyse the position of the field and tasked to develop a strategy, to re-visit the undoubtedly promising future of cardiovascular regenerative and reparative medicine, based on lessons learned over the past two decades. During the scientific retreat of the ESC Working Group on Cardiovascular Regenerative and Reparative Medicine (CARE) in November 2018, the most relevant and timely research aspects in regenerative and/or reparative medicine were presented and critically discussed, with the aim to lay out a strategy for the future development of the field. We report herein the main ideas and conclusions of that meeting. [ABSTRACT FROM AUTHOR]

Background: Influenza viruses must utilize host factors to complete their lifecycle. Species-specific differences in host factors between birds and mammals mean that avian influenza viruses (AIVs) replicate well in avian hosts but not in human hosts. Acidic nuclear phosphoprotein 32 family member A (ANP32A) has been identified as the host restriction factor for the viral polymerase (vPol) activity of AIVs. The ANP32A belongs to the conserved ANP32 family, the functional roles of which during viral replication remain unclear.Methods: In this study, we targeted chicken ANP32A using clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-mediated genome editing to examine the functional roles of ANP32A and other members of the ANP32 family.Results: We showed that chicken ANP32A only, not ANP32B and ANP32E, plays a pivotal role in supporting vPol activity of AIVs. Furthermore, we found that the human ANP32C, ANP32D, and ANP32E have suppressive effects on vPol activity in contrast to human ANP32A and ANP32B.Conclusions: Chicken and human ANP32 family members had different effects on vPol activity, suggesting that species-specific vPol activity of AIVs could be caused by the differential functions and overall competency of ANP32 family members. [ABSTRACT FROM AUTHOR]

There is an important unmet need for clinically validated non-invasive biomarkers for SSc diagnosis, assessment of disease activity, extent of internal organ involvement, therapeutic response and prognosis. There is also an unmet need for biomarkers to accurately differentiate primary RP from recent onset RP evolving into SSc. The lack of sensitive and specific biomarkers for SSc and SSc-associated RP is a limitation for the optimal clinical management of these patients. The development of highly sensitive and specific proteomic analysis employing aptamers and the expansion in the number of proteins that can be specifically identified by aptamer proteomics have opened new horizons for biomarker discovery. Here, we review the background and rationale for aptamer proteomic analysis for the identification of novel non-invasive biomarkers for SSc and recent onset RP evolving into SSc. Large scale application of aptamer proteomic platforms for this purpose will be of substantial value for the precision and personalized medical care of SSc patients. These studies will be placed in context by comparison with proteomic biomarker studies performed for other rheumatological inflammatory and autoimmune diseases. [ABSTRACT FROM AUTHOR]

Aims: Intracoronary infusion of autologous nucleated bone marrow cells (BMCs) enhanced the recovery of left ventricular ejection fraction (LVEF) after ST-segment elevation myocardial infarction (STEMI) in the randomised-controlled, open-label BOOST trial. We reassessed the therapeutic potential of nucleated BMCs in the randomised placebocontrolled, double-blind BOOST-2 trial conducted in 10 centres in Germany and Norway. Methods and Results: Using a multiple arm design, we investigated the dose-response relationship and explored whether c-irradiation which eliminates the clonogenic potential of stem and progenitor cells has an impact on BMC efficacy. Between 9 March 2006 and 16 July 2013, 153 patients with large STEMI were randomly assigned to receive a single intracoronary infusion of placebo (control group), high-dose (hi)BMCs, low-dose (lo)BMCs, irradiated hiBMCs, or irradiated loBMCs 8.1 ± 2.6 days after percutaneous coronary intervention (PCI) in addition to guideline-recommended medical treatment. Change in LVEF from baseline (before cell infusion) to 6 months as determined by MRI was the primary endpoint. The trial is registered at Current Controlled Trials (ISRCTN17457407). Baseline LVEF was 45.0 ± 8.5% in the overall population. At 6 months, LVEF had increased by 3.3 percentage points in the control group and 4.3 percentage points in the hiBMC group. The estimated treatment effect was 1.0 percentage points (95% confidence interval, -2.6 to 4.7; P = 0.57). The treatment effect of loBMCs was 0.5 percentage points (-3.0 to 4.1; P = 0.76). Likewise, irradiated BMCs did not have significant treatment effects. BMC transfer was safe and not associated with adverse clinical events. Conclusion: The BOOST-2 trial does not support the use of nucleated BMCs in patients with STEMI and moderately reduced LVEF treated according to current standards of early PCI and drug therapy. [ABSTRACT FROM AUTHOR]

Tumour necrosis factor ( TNF)-α, a proinflammatory cytokine central to many autoimmune diseases, has been implicated in the depigmentation process in vitiligo. We review its role in vitiligo by exploring its pro- and anti-inflammatory properties and examine the effects of blocking its actions with TNF-α antagonist therapeutics in reports available in the literature. We found that TNF-α inhibition halts disease progression in patients with progressive vitiligo but that, paradoxically, treatment can be associated with de novo vitiligo development in some patients when used for other autoimmune conditions, particularly when using adalimumab and infliximab. These studies reinforce the importance of stating appropriate outcomes measures, as most pilot trials propose to measure repigmentation, whereas halting depigmentation is commonly overlooked as a measure of success. We conclude that TNF-α inhibition has proven useful for patients with progressive vitiligo, where TNF-α inhibition is able to quash cytotoxic T-cell-mediated melanocyte destruction. However, a lingering concern for initiating de novo disease will likely prevent more widespread application of TNF inhibitors to treat vitiligo. [ABSTRACT FROM AUTHOR]

Aims The objective of the present analysis was to systematically examine the effect of intracoronary bone marrow cell (BMC) therapy on left ventricular (LV) function after ST-segment elevation myocardial infarction in various subgroups of patients by performing a collaborative meta-analysis of randomized controlled trials. Methods and results We identified all randomized controlled trials comparing intracoronary BMC infusion as treatment for ST-segment elevation myocardial infarction. We contacted the principal investigator for each participating trial to provide summary data with regard to different pre-specified subgroups [age, diabetes mellitus, time from symptoms to percutaneous coronary intervention, infarct-related artery, LV end-diastolic volume index (EDVI), LV ejection fraction (EF), infarct size, presence of microvascular obstruction, timing of cell infusion, and injected cell number] and three different endpoints [change in LVEF, LVEDVI, and LV end-systolic volume index (ESVI)]. Conclusion Intracoronary BMC infusion is associated with improvement of LV function and remodelling in patients after ST-segment elevation myocardial infarction. Younger patients and patients with a more severely depressed LVEF at baseline derived most benefit from this adjunctive therapy. [ABSTRACT FROM PUBLISHER]

Background Palmoplantar keratodermas (PPKs) are a group of highly heterogeneous diseases causing hyperkeratosis of the palms and soles. They can be inherited in an autosomal recessive, dominant, mitochondrial or possibly X-linked recessive fashion. The present study describes clinical and molecular genetic analysis of a consanguineous Pakistani family showing a severe form of PPK inherited in an autosomal recessive manner. Objectives To map the gene responsible for an autosomal recessive form of PPK. Methods Human genome scan using polymorphic microsatellite markers was performed to localize the disease gene. Eleven candidate genes, located in the linkage interval, were screened to identify the potential sequence variants. Results All five affected members of the family showed severe bilateral involvement of palms and soles with minor nail involvement, severe fissuring with bleeding, painful walking, and problems in grasping. Linkage analysis in the family mapped a novel locus for the disease on chromosome 3q27.2-q29. The candidate region flanked by markers D3S1530 and D3S1272 spans 28·22 cM, which corresponds to a physical distance of 11·63 Mb. The maximum two-point LOD score of 3·13 at θ = 0·00 was obtained with marker D3S2748 along the disease locus. DNA sequence analysis of 11 candidate genes, located in the linkage interval, failed to detect functional sequence variants. Conclusions A novel locus for an autosomal recessive form of PPK was mapped on chromosome 3q27.2-q29 in a consanguineous Pakistani family. Failure to detect pathogenic sequence variants in the 11 candidate genes suggests either that the variants are located in the regulatory regions of the genes or that another unknown gene, responsible for the disease, is present in the region. [ABSTRACT FROM AUTHOR]

Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) belong to the family of perfluorinated compounds. They are used in industrial and consumer applications, e.g., clothing fabrics, carpets, and food packaging. PFOS and PFOA are present in the environment and are found in dust and human milk, which implies that newborns and toddlers can be directly exposed to these agents during brain development. Recently, we reported that PFOS and PFOA can cause neurobehavioral defects and changes in the cholinergic system, in the adult animal, when given directly to neonatal mice, and thereby showing similarities with other investigated persistent organic pollutants, such as dichloro-diphenyl-trichloroethan, polychlorinated biphenyls, and polybrominated diphenyl ethers (PBDEs). In recent studies, we have also seen that highly brominated PBDEs can affect the levels of proteins that are important for neuronal growth and synaptogenesis in the neonatal mouse brain. The present study shows that a single oral dose of either 21 μmol PFOS or PFOA/kg body weight (11.3 or 8.70 mg), given directly to the neonatal mice on postnatal day 10, significantly increased the levels of CaMKII, GAP-43, and synaptophysin in the hippocampus of the neonatal mouse. Both compounds significantly increased the levels of synaptophysin and tau in cerebral cortex, and PFOA also increased the levels of tau in hippocampus. These proteins are important for normal brain development, and altered levels of these proteins during a critical period of the brain growth spurts could be one of the mechanisms behind earlier reported behavioral defects. [ABSTRACT FROM AUTHOR]

Adoptive immunotherapy with in vitro expanded antigen-specific cytotoxic T lymphocytes (CTLs) may be an effective approach to prevent, or even treat, Aspergillus (Asp) infections. Such lines can be generated using monocyte-derived dendritic cells (DC) as antigen-presenting cells (APC) but requires a relatively high volume of starting blood. Here we describe a method that generates Asp-specific CTL responses more efficiently using a protocol of antigen presented on DC followed by Epstein–Barr virus (EBV)-transformed B lymphoblastoid cell lines (BLCL) as APC. Peripheral blood mononuclear cells were stimulated weekly (2–5×) with a complete pool of pentadecapeptides (PPC) spanning the coding region of Asp f16 pulsed onto autologous mature DC. Cultures were split and stimulated subsequently with either PPC-DC or autologous PPC-pulsed BLCL (PPC-BLCL). Lines from the DC/BLCL arm demonstrated Asp f16-specific cytotoxicity earlier and to a higher degree than lines generated with PPC-DC alone. The DC/BLCL-primed lines showed a higher frequency of Asp f16-specific interferon (IFN)-γ producing cells but an identical effector cell phenotype and peptide specificity compared to PPC-DC-only-primed lines. Tumour necrosis factor (TNF)-α, but not IL-10, appeared to play a role in the effectiveness of BLCL as APC. These results demonstrate that BLCL serve as highly effective APC for the stimulation of Asp f16-specific T cell responses and that a culture approach using initial priming with PPC-DC followed by PPC-BLCL may be a more effective method to generate Asp f16-specific T cell lines and requires less starting blood than priming with PPC-DC alone. [ABSTRACT FROM AUTHOR]

Background Low expression of transporters associated with antigen processing (TAP) and human leucocyte antigen (HLA) class I, due to defects in the antigen presentation pathway, is frequently found in human tumours, including malignant melanoma (MM). This immune evasion renders many tumours unrecognizable by the host immune surveillance system and appears to play a role in the clinical course of the tumour, probably because it provides tumour cells with a mechanism to escape cytotoxic T-lymphocyte recognition and destruction. However, the histopathological significance of TAP and HLA class I antigen defects in MM remains unclear. Objective To study the expression of TAP and HLA class I antigen in MM and the relationship between them. To investigate the correlation between histopathological characteristics and expression of these molecules in MM. Methods Tissue sections from 77 patients with MM and 20 with naevi were examined using immunohistochemistry and morphological quantitative analysis for protein expression of TAP1, TAP2 and HLA class I antigen. Results Positive TAP1, TAP2 and HLA class I antigen immunostaining was observed in 23%, 12% and 64% of MM lesions, respectively, and the expression of HLA class I was positively correlated with that of TAP1 and TAP2. However, expression of these molecules was positive in all of the pigmented naevi lesions. Reduced TAP1 and TAP2 protein expression in melanoma lesions was significantly associated with invasive growth, Clark’s level and tumour-infiltrating lymphocytes. Reduced HLA class I antigen protein expression was only associated with tumour-infiltrating lymphocytes. Conclusions Our data suggest that reduced TAP1, TAP2 and HLA class I antigen protein expression in MM may contribute to the immune escape phenotype of human melanoma cells, and the main cause of reduced HLA class I expression may be the decreased TAP1 and TAP2 levels. [ABSTRACT FROM AUTHOR]

Many human tumor-associated antigens (TAAs) have recently been identified and molecularly characterized. When bound to major histocompatibility complex molecules, TAA peptides are recognized by T cells. Clinical studies have therefore been initiated to assess the therapeutic potential of active immunization or vaccination with TAA peptides in patients with metastatic cancer. So far, only a limited number of TAA peptides, mostly those recognized by CD8(+) T cells in melanoma patients, have been clinically tested. In some clinical trials, partial or complete tumor regression was observed in approximately 10%-30% of patients. No serious side effects have been reported. The clinical responses, however, were often not associated with a detectable T-cell-specific antitumor immune response when patients' T cells were evaluated in ex vivo assays. In this review, we analyze the available human TAA peptides, the potential immunogenicity (i.e., the ability to trigger a tumor-specific T-cell response) of TAA peptides in vitro and ex vivo, and the potential to construct slightly modified forms of TAA peptides that have increased T-cell stimulatory activity. We discuss the available data from clinical trials of TAA peptide-based vaccination (including those that used dendritic cells to present TAA peptides), identify possible reasons for the limited clinical efficacy of these vaccines, and suggest ways to improve the clinical outcome of TAA peptide-based vaccination for cancer patients. [ABSTRACT FROM AUTHOR]

Cytolytic T lymphocytes exert two main specific molecular killing mechanisms against target cells, namely (i) they can synthesize and release soluble cytolytic factors, and (ii) they can express effector molecules that act as ligands of receptors expressed by target cells on the cell surface; by these two pathways cytolytic T lymphocytes kill several targets, e.g. cells infected with intracellular pathogens, cells transformed by malignancy and cells producing autoantibodies. This review investigates the contribution from alterations in these molecular killing mechanisms to the pathogenesis of cutaneous diseases. In fact, molecular components involved in such killing mechanisms are often altered or distorted in skin pathology, e.g. cutaneous viral infections, skin cancer, contact hypersensitivity and autoimmune diseases with cutaneous involvement. Treatments capable of repairing the molecular components operating in such killing mechanisms could presumably favour the resolution of these skin diseases. [ABSTRACT FROM AUTHOR]

Examines the impaired regulation of apoptosis associated with the development of various cancers. Mechanism of Fas receptor binding on primary and metastatic melanoma cell; Correlation between measures of apoptosis and different disease stages; Use of functional assay and reverse transcriptase-polymerase chain reaction in the study.

Human immunodeficiency virus (HIV) disease is associated with loss of type 1 responses, including interleukin (IL)-12 production. The dramatic drop in p70 production seen at early stages of disease was found not to be associated with a similarly decreased p40 mRNA expression. p35 mRNA expression was more extensively reduced than p40mRNA expression at these early stages. Monocytes infected in vitro with HIV displayed decreased p35 expression and p70 production, suggesting that such decreased IL-12 expression may contribute to reduced IL-12 production in HIV-positive patients' cells. In addition, treatment of cells with IL-10 increased IL-10 mRNA expression and decreased p40 expression in both HIV-positive and -negative cells, while neutralization of IL-10 increased p40 mRNA levels. These observations, together with the observed hyperproduction of IL-10 in HIV-positive patients, may explain the dysregulation of IL-12 production seen in HIV disease. [ABSTRACT FROM PUBLISHER]

Engagement of monocytic cell membrane proteins was shown to enhance human immunodeficiency virus type 1 (HIV-1) replication in monocytic cells. Cross-linking of CD18, CD11a, or CD45 by immobilized antibodies produced up to an 11-fold enhancement of HIV-1 release in the OM10.1 monocytic cell line in a tumor necrosis factor-α (TNF-α)-dependent manner. In addition, adhesion of OM10.1 cells to immobilized intercellular adhesion molecule-1 (ligand for CD18/CD11a) induced similar TNF-α-dependent enhancement of HIV-l replication. After phenotypic differentiation of OM10.1 cells, engagement of cell membrane proteins CD18, CD1la, CD44, CD45, or CD58 by soluble antibodies enhanced HIV-1 replication in a TNF-α-dependent manner. These data suggest that cross-linkage of monocytic cell membrane proteins during cell-cell interaction and specifically during antigen presentation to CD4 T cells may enhance HIV-1 replication, facilitating infection of adjacent cells. [ABSTRACT FROM PUBLISHER]

Examines the hypersensitivity reactions to chemotherapy agents of patients receiving chemoimmunotherapy with high-dose Interleukin 2 (IL-2). Background of the study; Effect on weight and on white blood cell and eosinophil counts; Immunologic effects of IL-2; Mechanism by which IL-2 may induce hypersensitivity reactions.

Pretreatment of human peripheral blood lymphocytes (PBL) with cisplatin (CDDP) before in vitro culture with interleukin-2 (IL-2) inhibited the generation of lymphokine-activated killer (LAK) cells and strongly inhibited proliferation. This inhibition was dose dependent, was significant only at concentrations greater than 6 μ, and it required exposure to the drug for more than 1 hour. This period of IL-2 unresponsiveness was maximum at, 6 hours, but was spontaneously recovered within 24–48 hours and was more rapidly restored by increasing dosages of IL-2. Because inhibition of the generation of LAK cells by CDDP was observed only at relatively high levels ofexposure to the drug (<6μ for <1 hr), it was important that we explore the in vivo significance of these findings. The peripheral blood lymphocytes from patients bearing ovarian adenocarcinoma collected 1 hour after an iv infusion of 50 mg of CDDP/m were not inhibited, compared with those collected immediately before therapy. Relatively high levels of exposure to CDDP are required for inhibition of the generation of new cytotoxic effectors, most likely because of its antiproliferative effect. These results may bear relevance to approaches involving the combined use of CDDP and IL-2-LAK. [J Natl Cancer Inst 82: 139–142, 1990] [ABSTRACT FROM PUBLISHER]

The expression of membrane-bound Fas ligand (FasL) and Fas in lymphocytes and monocytes and levels of soluble forms of FasL (sFasL) and Fas (sFas) in plasma from human immunodeficiency virus (HIV)—positive and -negative subjects was evaluated. Surface FasL was detectable on monocytes, but poorly so on lymphocytes, even in the presence of KB8301, a metalloproteinase inhibitor. Unexpectedly, monocytes of HIV-positive subjects expressed less FasL than those of HIV-negative volunteers. sFasL levels in plasma of HIV-positive persons were elevated and correlated with levels in plasma and with HIV RNA burden. sFas levels in plasma of HIV-positive subjects were also elevated and correlated with Fas expression in apoptotic lymphocytes. Finally, culture-induced lymphocyte apoptosis of HIV-positive subjects was enhanced by anti-Fas agonistic antibody but was not inhibited by anti-FasL blocking antibodies. These results suggest that significant dysregulation of both Fas and FasL occurs in HIV infection and contributes to increased sensitivity of lymphocytes to apoptosis. [ABSTRACT FROM PUBLISHER]

In this study we determined TCR α and β chain nucleotide sequences of HLA-Cw*1601-restricted cytotoxic T lymphocyte (CTL) clones obtained from the peripheral blood lymphocytes (PBL) of a melanoma patient. These clones were previously shown to be involved In the recognition of melanoma-associated antlgenic epitopes SAYGEPRKL and AARAVFLAL encoded by gene MAGE-1 and BAGE respectively. All (3/3) antl-MAGE-1 CTL clones displayed TCRBV5 usage and one clonotype was found twice, >1 year apart, in patient's PBL. Two out of three anti-BAGE CTL clones showed the same TCRAV/AJ and TCRBV/BJ combinations and differed in the α chain CDR3 for two residues and in the β chain CDR3 for a single nucleotide which, however, did not change translation. These results suggest a pattern of TCR conservation in CTL selected for recognition of MAGE-1 or BAGE peptides on the autologous melanoma. [ABSTRACT FROM AUTHOR]

The chemoattractant cytokine IL-16 has been reported to suppress lymphocyte activation and to inhibit HIV-1 replication in acutely infected T cells. We have cloned and expressed human IL-16 in Escherichia coli and investigated whether the recombinant protein could regulate the level of lymphocyte apoptosis from HIV-1-infected subjects. After purification and refolding, only 2–10% of the recombinant cytokine was present in a biologically active homotetrameric form. This could explain the need for high concentrations of the bacterially derived IL-16 to induce significant inhibition of HIV-1 replication. Addition of IL-16 to unstimulated peripheral blood mononuclear cell (PBMC) cultures from HIV-1-infected subjects did not modify the observed level of spontaneous lymphocyte apoptosis. In contrast, IL-16 added to PBMC cultures stimulated with anti-CD3, anti-CD95 or dexamethasone reduced significantly the percentage of lymphocytes undergoing AICD. This effect was found to correlate with the ability of the cytokine to decrease CD95 expression on activated CD4+ T cells. Comparative studies on PBMC from healthy individuals indicated that the regulation of apoptosis levels by IL-16 is a complex phenomenon and could depend on the nature of the activator used and/or the immune status of lymphocytes tested. The outcome of CD4 cross-linking on T cells by various ligands is discussed in the context of the observed beneficial activities of IL-16 and its potential role in the treatment of HIV disease. [ABSTRACT FROM AUTHOR]

Studies the low frequency of ErbB-2 proto-oncogene overexpression in human leukocyte antigen-a2-positive breast cancer patients. Major histocompatibility complex class I molecules as antigens; Encoding of a transmembrane glycoprotein by ErbB-2; Assessment of the estrogen receptor and progesterone receptor.

In order to determine the mechanism of tumour destruction by tumour-infiltrating lymphocytes (TIL), we examined the ability of both CD4[sup +] and CD8[sup +] effector TIL, and TIL clones, to manifest granzyme-mediated and Fas-mediated destruction of tumour targets. In many in vitro studies TIL have been shown to manifest anti-tumour reactivity, yet many tumours escape immunological destruction. To investigate the role of Fas expression and the concomitant sensitivity to the inducibility of apoptotic death, we derived TIL from four melanomas and one glioma. The glioma, and all but one of the melanomas, expressed Fas, but Fas-mediated apoptosis could only be detected if the targets were treated with cyclohexamide. The melanomas and the glioma all expressed detectable cytoplasmic Bcl-2 protein, known to exert anti-apoptotic activity. Lysis of tumours by CD8-enriched cultures and CD8[sup +] clones was Ca[sup 2+]-dependent and could not be modified by an anti-Fas MoAb. In CD4-enriched cultures or CD4[sup +] clones with cytotoxic potential against tumour cells, cytotoxicity was also Ca[sup 2+]-dependent. As Ca[sup 2+]-dependent cytotoxicity is usually the result of secretion of perforin/granzyme-B, we investigated the presence of perforin in cytotoxic CD4[sup +] clones and demonstrated the presence of granular deposits of this enzyme in some of the CD4[sup + ]clones. Although an anti-Fas MoAb did not block the lysis of melanoma targets by CD4[sup +] clones, the examination of Fas-dependent targets demonstrated that these clones also had the potential to kill by the Fas/Fas ligand system. These data suggest that the predominant mechanism in tumour killing by TIL appears to be perforin–granzyme-dependent, and that the solid tumour cell lines we studied are less susceptible to Fas-mediated apoptosis. As non-apoptotic pathways may enhance tumour immunogenicity, exploitation of the perforin–granzyme-dependent cytotoxic T lymphocyte (CTL) pathways may be... [ABSTRACT FROM AUTHOR]