Image-based multiplex immune profiling of cancer tissues: translational implications. A report of the International Immuno-oncology Biomarker Working Group on Breast Cancer

Recent advances in the field of immuno-oncology have brought transformative changes in the management of cancer patients. The immune profile of tumours has been found to have key value in predicting disease prognosis and treatment response in various cancers. Multiplex immunohistochemistry and immunofluorescence have emerged as potent tools for the simultaneous detection of multiple protein biomarkers in a single tissue section, thereby expanding opportunities for molecular and immune profiling while preserving tissue samples. By establishing the phenotype of individual tumour cells when distributed within a mixed cell population, the identification of clinically relevant biomarkers with high-throughput multiplex immunophenotyping of tumour samples has great potential to guide appropriate treatment choices. Moreover, the emergence of novel multi-marker imaging approaches can now provide unprecedented insights into the tumour microenvironment, including the potential interplay between various cell types. However, there are significant challenges to widespread integration of these technologies in daily research and clinical practice. This review addresses the challenges and potential solutions within a structured framework of action from a regulatory and clinical trial perspective. New developments within the field of immunophenotyping using multiplexed tissue imaging platforms and associated digital pathology are also described, with a specific focus on translational implications across different subtypes of cancer. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Pitfalls in machine learning-based assessment of tumor-infiltrating lymphocytes in breast cancer: A report of the International Immuno-Oncology Biomarker Working Group on Breast Cancer

The clinical significance of the tumor-immune interaction in breast cancer is now established, and tumor-infiltrating lymphocytes (TILs) have emerged as predictive and prognostic biomarkers for patients with triple-negative (estrogen receptor, progesterone receptor, and HER2-negative) breast cancer and HER2-positive breast cancer. How computational assessments of TILs might complement manual TIL assessment in trial and daily practices is currently debated. Recent efforts to use machine learning (ML) to automatically evaluate TILs have shown promising results. We review state-of-the-art approaches and identify pitfalls and challenges of automated TIL evaluation by studying the root cause of ML discordances in comparison to manual TIL quantification. We categorize our findings into four main topics: (1) technical slide issues, (2) ML and image analysis aspects, (3) data challenges, and (4) validation issues. The main reason for discordant assessments is the inclusion of false-positive areas or cells identified by performance on certain tissue patterns or design choices in the computational implementation. To aid the adoption of ML for TIL assessment, we provide an in-depth discussion of ML and image analysis, including validation issues that need to be considered before reliable computational reporting of TILs can be incorporated into the trial and routine clinical management of patients with triple-negative breast cancer. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Spatial analyses of immune cell infiltration in cancer: current methods and future directions: A report of the International Immuno-Oncology Biomarker Working Group on Breast Cancer

Modern histologic imaging platforms coupled with machine learning methods have provided new opportunities to map the spatial distribution of immune cells in the tumor microenvironment. However, there exists no standardized method for describing or analyzing spatial immune cell data, and most reported spatial analyses are rudimentary. In this review, we provide an overview of two approaches for reporting and analyzing spatial data (raster versus vector-based). We then provide a compendium of spatial immune cell metrics that have been reported in the literature, summarizing prognostic associations in the context of a variety of cancers. We conclude by discussing two well-described clinical biomarkers, the breast cancer stromal tumor infiltrating lymphocytes score and the colon cancer Immunoscore, and describe investigative opportunities to improve clinical utility of these spatial biomarkers. © 2023 The Pathological Society of Great Britain and Ireland.

SARS-CoV-2 testing and its role in understanding the evolving landscape of the pandemic in Bangladesh

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is readily transmitted from person to person. We evaluated the emerging landscape of SARS-CoV-2 variants in Bangladesh from a retrospective study of nasopharyngeal swabs collected from 130 SARS-CoV-2-positive cases randomly selected over 6 months. Mutation analysis of whole-genome sequencing of 130 SARS-CoV-2 variants revealed 528 unique coding mutations, of which 102 were deletions, 6 were premature stop codons, and the remaining were substitutions. The most common mutation in the cohort was ORF1b:P314L, with a frequency of 98.5%. A total of 132 unique coding mutations were observed in the spike protein gene. Fourteen mutations were mapped to the spike protein receptor binding domain (RBD). These mutations increase the affinity between the spike protein and its human receptor, angiotensin converting enzyme 2 (ACE2), thereby increasing SARS-CoV-2 transmissibility. This study will help understand the SARS-CoV-2 virus and ultimately aid in monitoring and combatting the COVID-19 pandemic by furthering research on appropriate therapies. Analysis of age revealed closer association of the Delta variant with older populations and of the Omicron variant with younger populations. This may have important implications on how we monitor infections, distribute vaccines, and treat patients based on their ages.

The tale of TILs in breast cancer: A report from The International Immuno-Oncology Biomarker Working Group

The advent of immune-checkpoint inhibitors (ICI) in modern oncology has significantly improved survival in several cancer settings. A subgroup of women with breast cancer (BC) has immunogenic infiltration of lymphocytes with expression of programmed death-ligand 1 (PD-L1). These patients may potentially benefit from ICI targeting the programmed death 1 (PD-1)/PD-L1 signaling axis. The use of tumor-infiltrating lymphocytes (TILs) as predictive and prognostic biomarkers has been under intense examination. Emerging data suggest that TILs are associated with response to both cytotoxic treatments and immunotherapy, particularly for patients with triple-negative BC. In this review from The International Immuno-Oncology Biomarker Working Group, we discuss (a) the biological understanding of TILs, (b) their analytical and clinical validity and efforts toward the clinical utility in BC, and (c) the current status of PD-L1 and TIL testing across different continents, including experiences from low-to-middle-income countries, incorporating also the view of a patient advocate. This information will help set the stage for future approaches to optimize the understanding and clinical utilization of TIL analysis in patients with BC.

Psychometric properties of the Malay version of motivation scales in drug treatment

INTRODUCTION

In recognition of the role of motivation in drug use treatment, patient motivational screening instruments are needed for strategic planning and treatment. The aims of this study were to evaluate the reliability and validity of the Malay version of the Treatment Motivation Scale, and to compare the motivational levels of patients receiving substance abuse treatment with different modalities (inpatient vs. outpatient). The motivational scale consists of three scales: problem recognition, desire for help and treatment readiness.

METHOD

A convenience sample of 102 patients was recruited from four Cure and Care Service Centres in Malaysia.

RESULTS

Principal component analysis with varimax rotation supported two-factor solutions for each subscale: problem recognition, desire for help and treatment readiness, which accounted for 63.5%, 62.7% and 49.1% of the variances, respectively. The Cronbach's alpha coefficients were acceptable for the overall measures (24 items: ∝ = 0.89), the problem recognition scale (10 items; ∝ = 0.89), desire for help (6 items; ∝ = 0.64) and treatment readiness scale (8 items; ∝ = 0.60). The results also indicated significant motivational differences for different modalities, with inpatients having significantly higher motivational scores in each scale compared to outpatients.

CONCLUSION

The present study pointed towards the favourable psychometric properties of a motivation for treatment scale, which can be a useful instrument for clinical applications of drug use changes and treatment.

Citrate Suppresses Tumor Growth in Multiple Models through Inhibition of Glycolysis, the Tricarboxylic Acid Cycle and the IGF-1R Pathway

In this study we have tested the efficacy of citrate therapy in various cancer models. We found that citrate administration inhibited A549 lung cancer growth and additional benefit accrued in combination with cisplatin. Interestingly, citrate regressed Ras-driven lung tumors. Further studies indicated that citrate induced tumor cell differentiation. Additionally, citrate treated tumor samples showed significantly higher infiltrating T-cells and increased blood levels of numerous cytokines. Moreover, we found that citrate inhibited IGF-1R phosphorylation. In vitro studies suggested that citrate treatment inhibited AKT phosphorylation, activated PTEN and increased expression of p-eIF2a. We also found that p-eIF2a was decreased when PTEN was depleted. These data suggest that citrate acts on the IGF-1R-AKT-PTEN-eIF2a pathway. Additionally, metabolic profiling suggested that both glycolysis and the tricarboxylic acid cycle were suppressed in a similar manner in vitro in tumor cells and in vivo but only in tumor tissue. We reproduced many of these observations in an inducible Her2/Neu-driven breast cancer model and in syngeneic pancreatic tumor (Pan02) xenografts. Our data suggests that citrate can inhibit tumor growth in diverse tumor types and via multiple mechanisms. Dietary supplementation with citrate may be beneficial as a cancer therapy.

Body dysmorphic disorder: beyond skin deep

Body dysmorphic disorder (BDD) is a psychiatric illness that primarily affects adolescents and young adults of both sexes. Patients have a distorted self-image, which manifests as a preoccupation with slight or imagined defects in the face, nose, skin, hair or any part of the body that ultimately interferes with daily functioning. It is a relatively common yet long unrecognized problem. Patients often seek multiple physician assessments for their perceived defects and request cosmetic procedures. Early intervention can prevent a cycle of multiple surgeries, as the outcome is usually poor and may lead to exacerbation of symptoms, anger and litigation. BDD is a disabling, and even life-threatening, condition; it can lead to major depression and suicidal ideation. Selective serotonin reuptake inhibitors and cognitive behavioral therapy are the mainstay of treatment and are beneficial in most patients. A multidisciplinary approach is strongly recommended.

Tumor-derived lactate and myeloid-derived suppressor cells: Linking metabolism to cancer immunology

Many malignant cells produce increased amounts of lactate, which promotes the development of myeloid-derived suppressor cells (MDSCs). MDSCs, lactate, and a low pH in the tumor microenvironment inhibit the function of natural killer (NK) cells and T lymphocytes, hence allowing for disease progression. Ketogenic diets can deplete tumor-bearing animals from MDSCs and regulatory T cells, thereby improving their immunological profile.

Tumor-derived lactate modifies antitumor immune response: effect on myeloid-derived suppressor cells and NK cells

In this study, we explore the hypothesis that enhanced production of lactate by tumor cells, because of high glycolytic activity, results in inhibition of host immune response to tumor cells. Lactate dehydrogenase-A (LDH-A), responsible for conversion of pyruvate to lactate, is highly expressed in tumor cells. Lentiviral vector-mediated LDH-A short hairpin RNA knockdown Pan02 pancreatic cancer cells injected in C57BL/6 mice developed smaller tumors than mice injected with Pan02 cells. A decrease occurred in the frequency of myeloid-derived suppressor cells (MDSCs) in the spleens of mice carrying LDH-A-depleted tumors. NK cells from LDH-A-depleted tumors had improved cytolytic function. Exogenous lactate increased the frequency of MDSCs generated from mouse bone marrow cells with GM-CSF and IL-6 in vitro. Lactate pretreatment of NK cells in vitro inhibited cytolytic function of both human and mouse NK cells. This reduction of NK cytotoxic activity was accompanied by lower expression of perforin and granzyme in NK cells. The expression of NKp46 was decreased in lactate-treated NK cells. These studies strongly suggest that tumor-derived lactate inhibits NK cell function via direct inhibition of cytolytic function as well as indirectly by increasing the numbers of MDSCs that inhibit NK cytotoxicity. Depletion of glucose levels using a ketogenic diet to lower lactate production by glycolytic tumors resulted in smaller tumors, decreased MDSC frequency, and improved antitumor immune response. These studies provide evidence for an immunosuppressive role of tumor-derived lactate in inhibiting innate immune response against developing tumors via regulation of MDSC and NK cell activity.

Conversion of peripheral blood NK cells to a decidual NK-like phenotype by a cocktail of defined factors

NK cells that populate the decidua are important regulators of normal placentation. In contrast to peripheral blood NK cells, decidual NK (dNK) cells lack cytotoxicity, secrete proangiogenic factors, and regulate trophoblast invasion. In this study we show that exposure to a combination of hypoxia, TGF-β1, and a demethylating agent results in NK cells that express killer cell Ig-like receptors, the dNK cell markers CD9 and CD49a, and a dNK pattern of chemokine receptors. These cells secrete vascular endothelial growth factor (a potent proangiogenic molecule), display reduced cytotoxicity, and promote invasion of human trophoblast cell lines. These findings have potential therapeutic applications for placental disorders associated with altered NK cell biology.

Protective KIR-HLA interactions for HCV infection in intravenous drug users

Intravenous drug use has become the principal route of hepatitis C virus (HCV) transmission due to the sharing of infected needles. In this study, we analyzed the distribution of HLA-KIR genotypes among 160 Puerto Rican intravenous drug users (IDUs) with HCV infection and 92 HCV-negative Puerto Rican IDUs. We found a significant association between the presence of different combinations of KIR inhibitory receptor genes (KIR2DL2 and/or KIR2DL3, pC=0.01, OR=0.07; KIR2DL2 and/or KIR2DL3+KIR2DS4, pC=0.01, OR=0.39) and HLA-C1 homozygous genotypes (HLA-C1+KIR2DS4, pC=0.02, OR=0.43; HLA-C1+KIR2DL2+KIR2DS4, pC=0.02, OR=0.40) together with the activating receptor KIR2DS4 (HLA-C1+KIR2DS4+KIR2DL3 and/or KIR2DL2, pC=0.004, OR=0.38) with protection from HCV infection. Our findings in HCV-infected and non-infected IDUs suggest an important role for KIRs (KIR2DL2 and KIR2DL3) with group HLA-C1 molecules, in the presence of activating KIR2DS4, in protection from HCV infection. These results support the hypothesis that activator signaling, mediated by KIR2DS4, plays a determinant role in the regulation of NK cell antiviral-activity.

Interaction of NK inhibitory receptor genes with HLA-C and MHC class II alleles in Hepatitis C virus infection outcome

Natural killer cells are important in innate defense against viral infections. The interplay between stimulatory and inhibitory natural killer cell receptors and their corresponding human leukocyte antigen ligands are known to influence the outcome of acute Hepatitis C virus infection. Frequencies of NK receptor genes (8 inhibitory, 6 activating and 2 pseudogenes) and HLA class II alleles (DRB1, DQB1) were analyzed in 160 Puerto-Rican American drug users with Hepatitis C virus infection; 121 had chronic viremia (CV) and 39 were spontaneous clearance (SC). We further ruled out genetic stratification using short tandem repeats. Interaction between KIR gene receptor 2DL3/2DL3 and its ligand, C1/C1 of HLA-Cw alleles and spontaneous clearance was confirmed (p=0.03, OR=3.05). We also found a new interaction between the KIR receptor gene 2DL3 with HLA-DRB1*1201 (p=0.0001, OR=22) associated with SC, and an association of HLA DQB1*0501 (p=0.05, OR=0.30) with CV. Our findings suggested a role for MHC class II alleles in Hepatitis C virus peptide presentation to T cells together with NK ligand interaction involving pathways that will be useful for the development of immunotherapeutic interventions.

The MHC type 1 diabetes susceptibility gene is centromeric to HLA-DQB1

HLA-DQB1 is widely considered to be the major histocompatibility complex (MHC) susceptibility gene for type 1 diabetes (T1D). However, since inheritance of the gene in T1D is recessive, the presence of the protective HLA-DQB1 0602 allele with normal nucleotide sequence in some patients raises the question of whether HLA-DQB1 is not the susceptibility locus itself but merely a good marker. HLA-DQB1 0602 is part of a conserved extended haplotype (CEH) [HLA-B7, SC31, DR2] (B7, DR2) with fixed DNA over more than 1Mb of genomic DNA that normally carries a protective allele at the true susceptibility locus. We postulated that, in patients with HLA-DQB1 0602, the protective allele at the susceptibility locus has been replaced by a susceptibility allele through an ancient crossover at meiosis centromeric to HLA-DQB1. We analyzed single nucleotide polymorphisms (SNPs) distinguishing the HLA-DQA2 (the first expressed gene centromeric to HLA-DQB1) allele on the normal HLA-B7, DR2 CEH from those on susceptibility CEHs in T1D patients and controls with HLA-DQB1 0602. All but 1 of 20 healthy control HLA-DQB1 0602 haplotypes had identical (consensus) first intron HLA-DQA2 5-SNP haplotypes. Fifteen of 19 patients with HLA-DQB1 0602 were homozygous for 1 or more HLA-DQA2 SNPs differing from consensus HLA-DQA2 SNPs, providing evidence of crossover involving the HLA-DQA2 locus. The remaining 4 patients were heterozygous at all positions and therefore uninformative. The loss of dominant protection usually associated with HLA-DQB1 0602 haplotypes is consistent with a locus centromeric to HLA-DQB1 being a major determinant of MHC-associated susceptibility, and perhaps the true T1D susceptibility locus.

Incomplete penetrance of susceptibility genes for MHC-determined immunoglobulin deficiencies in monozygotic twins discordant for type 1 diabetes

Incomplete intrinsic penetrance is the failure of some genetically susceptible individuals (e.g., monozygotic twins of those who have a trait) to exhibit that trait. For the first time, we examine penetrance of susceptibility genes for multiple MHC gene-determined traits in the same subjects. Serum levels of IgA, IgD, IgG3, but not IgG4, in 50 pairs of monozygotic twins discordant for type 1 diabetes (T1D) correlated more closely in the twins than in random paired controls. The frequencies of subjects deficient in IgA (6%), IgD (33%) and IgG4 (12%), but not in IgG3, were higher in the twins than in controls. We postulate that this was because the MHC haplotypes (and possible non-MHC genes) that predispose to T1D also carry susceptibility genes for certain immunoglobulin deficiencies. Immunoglobulin deficiencies were not associated with T1D. Pairwise concordance for the deficiencies in the twins was 50% for IgA, 57% for IgD and 50% for IgG4. There were no significant associations among the specific immunoglobulin deficiencies except that all IgA-deficient subjects had IgD deficiency. Thus, intrinsic penetrance is a random process independently affecting different MHC susceptibility genes. Because multiple different external triggers would be required to explain the results, differential environmental determinants appear unlikely.

Increased FasL expression correlates with apoptotic changes in granulocytes cultured with oxidized clozapine

Clozapine has been associated with a 1% incidence of agranulocytosis. The formation of an oxidized intermediate clozapine metabolite has been implicated in direct polymorphonuclear (PMN) toxicity. We utilized two separate systems to analyze the role of oxidized clozapine in inducing apoptosis in treated cells. Human PMN cells incubated with clozapine (0-10 microM) in the presence of 0.1 mM H2O2 demonstrated a progressive decrease of surface CD16 expression along with increased apoptosis. RT-PCR analysis showed decreased CD16 but increased FasL gene expression in clozapine-treated PMN cells. No change in constitutive Fas expression was observed in treated cells. In HL-60 cells induced to differentiate with retinoic acid (RA), a similar increase in FasL expression, but no associated changes in CD16 gene expression, was observed following clozapine treatments. Our results demonstrate increased FasL gene expression in oxidized clozapine-induced apoptotic neutrophils suggesting that apoptosis in granulocytes treated with clozapine involves Fas/FasL interaction that initiates a cascade of events leading to clozapine-induced agranulocytosis.

Increased apoptosis of CD20+ IgA + B cells is the basis for IgA deficiency: the molecular mechanism for correction in vitro by IL-10 and CD40L

IgA deficiency is the most common primary immunodeficiency in humans. Comparative analysis of gene expression in PBMC from IgA-deficient (IgAd) and normal donors using functional multiplex panels showed overexpression of the Caspase-1 (CASP-1) gene. Cells from all the IgAd donors (n=7) expressed 4-10-fold caspase-1 mRNA over normal controls (n=5). CD19(+) B cells from all IgAd donors produced IgA in cultures following IL-10 and CD40L with Staphylococcus aureus (Cowan) (SAC) or tetanus toxoid (TT) treatments. In CD19(+) B cells from IgAd donors, reconstitution of IgA secretion was associated with protection of the CD20(+) B cell population that underwent apoptosis in the absence of IL-10, CD40L, and TT (triple treatment). Caspase-1 gene expression was decreased in the reconstituted cells. Furthermore, treatment with a caspase-1 inhibitor also independently protected against B cell apoptosis in vitro. An apoptosis-specific cDNA array showed differential expression of 4 out of 96 genes and a shift towards survival-related gene expression from the apoptotic to the protected B cells after triple treatment. There was an increase in the expression of the IAP-2 (inhibitor of apoptosis) gene in the reconstituted cells. Upregulation of the IAP-2 gene protects B cells from deletion and allows for IgA secretion in this system. The inability to detect secreted IgA in IgAd patients could result from the loss of IgA-committed B cells that express high levels of caspase-1.

Stem Cells in Aging: Influence of Ontogenic, Genetic and Environmental Factors

Aging is a genetically programmed decline in the functional effectiveness of the organism. It is manifested by a collective group of changes in cells or organs that occur over the course of a lifespan, limiting the duration of life. Longevity usually refers to long-lived members of a population within species. Organs develop and can involute according to specific timetables. Such timetables correlate with a preordained proliferative capacity of cells mediated by cell and organ clocks. In this review, we discuss different aspects related to genetic and environmental factors that are involved in determining life span. We discuss the influence of ontogenic, genetic and environmental factors in aging. The genetic factors can be studied in embryonic stem cells (ESC) and in niches (microenvironments) of stem cells (SC) using cellular or experimental animal models. We discuss molecular mechanisms involving genes and proteins associated with death pathways, niches, or hubs, on longevity. Moreover, we also discuss genes and proteins, associated with death pathways, on longevity. Unraveling these mechanisms may further our understanding of human aging leading to development of therapeutic interventions with the potential of prolonging life.

HLA-Cw*0409N is associated with HLA-A*2301 and HLA-B*4403-carrying haplotypes

The associations of HLA-B*4402 and HLA-B*4403 with alleles of HLA-A and HLA-Cw were investigated in panels of HLA-B*4403 and HLA-B*4402 homozygous individuals and in selected individuals carrying HLA-Cw*04 and HLA-B*4403. Some of these individuals were genotyped and also carried (HLA-DRB1*0701, DQB1*02). Among the latter, we studied individuals carrying the conserved extended haplotype (CEH) [HLA-Cw*04, B*4403, FC31, DRB1*0701, DQB1*02]. Four different common (HLA-Cw*, B*44) haplotypes were identified that extended to the HLA-A locus: HLA-A*0201, Cw*0501, B*4402; HLA-A*2902, Cw*1601, B*4403; HLA-A*2301, Cw*0401, B*4403; and HLA-A*2301, Cw*0409N, B*4403. We identified eight unrelated examples of the allele HLA-Cw*0409N. HLA-A*2301 was associated with both HLA-Cw*0401 and HLA-Cw*0409N, suggesting that HLA-Cw*0409N may have arisen from a mutation in a CEH. We estimate that approximately 2 to 5 in 1000 Caucasian individuals carry the allele HLA-Cw*0409N, making it one of the most frequent null HLA alleles known to date. Our findings demonstrate the first example of three different HLA-Cw-determined subtypes of a common or CEH carrying a shared HLA-B allele, in this case HLA-B*4403.

Positive selection vectors for high-fidelity PCR cloning

The power of PCR cloning of a target DNA fragment is limited by polymerase-induced mutations. While high-fidelity PCR products can be achieved by reducing the number of PCR cycles, the cloning of the very small amount of DNA thus amplified should give only a few recombinant clones (carrying an insert), which would be very difficult to screen from thousands of background false-positive clones generated by all the currently available vectors, including the positive selection vectors. False-positive clones are mostly generated by the recircularization of linearized vectors that have lost some bases at their ends due to digestion with contaminating exonuclease activities present in restriction enzymes, ligases, polymerases, and other reagents. To overcome this problem, two positive selection vectors, pRGR1Ap and pREM5Tc, have been developed, based on the principles of reporter gene reconstruction and regulatory element modulation, respectively. A PCR primer carrying a vector-specific sequence at its 5' end is used in PCR. When the resultant PCR products are ligated to the specific vector, an antibiotic resistance gene is expressed, thus donating positive selection capability to the harboring cells in a specific selection medium. These vectors cloned PCR fragments generated from less than a femtomole quantity of Escherichia coli genomic DNA after only three cycles of PCR amplification, thus greatly reducing the number of recombinant clones containing polymerase-induced mutations.

Complex expression of natural killer receptor genes in single natural killer cells

Human natural killer (NK) cells express several inhibitory and non-inhibitory NK receptors per cell. Understanding the expression patterns of these receptor genes in individual cells is important to understanding their function. Using a single-cell reverse transcription-polymerase chain reaction (RT-PCR) method, we analysed the expression of nine NK receptor genes in 38 resting CD56+ NK cells from peripheral blood of normal donors. We observed highly diverse patterns of receptor expression in these cells. No NK receptor is expressed universally in every CD56+ NK cell. The expressed receptor types per cell varied from two to eight. We specifically analysed the distribution of inhibitory (DL) and non-inhibitory (DS) killer immunoglobulin-like receptors (KIR). The frequency of individual receptor expression varied from 26% for 2DS2 to 68% for both 2DL1 and 2DL4. A comparison of the coexpression of DL and DS receptors showed a significant association in the expression of 2DL2 and 2DS2 (chi2=16.6; P<0.001) genes but no association between 2DL1 and 2DS1 or between 3DL1 and 3DS1 genes. Coexpression analysis of the 2DL1 and 2DL2 genes in 2DL4+ and 2DL4- cells showed a strong association in 2DL4+ but not in 2DL4- cells, suggesting a differential effect of the 2DL4 gene on the expression of 2DL1 and 2DL2 genes. Single-cell RT-PCR is a powerful tool to study multiple receptor gene expression ex vivo in individual NK cells and provides information about the expression pattern of KIR receptors that may suggest mechanisms of gene expression responsible for generation of the KIR repertoire.

Felbamate-induced apoptosis of hematopoietic cells is mediated by redox-sensitive and redox-independent pathways

Felbamate (FBM; 2-phenyl-1,3-propanediol dicarbamate) is an approved antiepileptic drug shown to be effective in a variety of seizure disorders refractory to other treatments. However, its use has been restricted because of association with occurrence of rare cases of aplastic anemia and hepatic failure. Since it was shown that FBM metabolism requires glutathione (GSH), we used two experimental protocols to determine if the effects of specific metabolites were sensitive to redox pathways. FBM and its metabolite W873 (2-phenyl-1,3-propanediol monocarbamate), at 0.1 mg/ml, induced increased apoptosis of bone marrow cells from B10.AKM mice as compared with B10.BR mice. Study of the effects of the drug on human promonocytic cell line U937 cells showed that FBM and the metabolite W2986 [2-(4-hydroxyphenyl)-1,3 propanediol dicarbamate], at higher concentrations (0.5 mg/ml), induced apoptosis in this cell line. We also observed that while FBM and its metabolites induced increased apoptosis of B cells with reduced intracellular GSH levels, addition of exogenous GSH decreased apoptosis induced by W873 but did not significantly affect apoptosis induced by FBM or W2986. Our results suggest that, at concentrations used during the present investigations, FBM metabolites induce apoptosis via redox-sensitive and redox-independent pathways.

HLA-Cw7 zygosity affects the size of a subset of CD158b+ natural killer cells

Individuals with certain HLA class I genotypes are highly susceptible to disease after viral infection. Natural killer (NK) cells kill virus-infected cells through a mechanism involving HLA class I receptors. These facts may be connected if an individual's HLA genotype regulates the number and function of NK cells. We have observed that subjects homozygous for the HLA-B/C region of conserved major histocompatibility complex (MHC) extended haplotypes have lower NK cell activity and a significantly lower frequency of CD16+CD56+ NK cells than heterozygotes. The proportion of CD16-CD56+ NK cells was unaffected by zygosity for the HLA-B/C region. We show here that the frequency of CD16+CD158b+, but not CD16-CD158b+ NK cells, was significantly lower (p <0.026) in homozygotes for HLA-Cw7 (NKI ligand) haplotypes than in heterozygotes. The frequencies of CD16+CD158a+ and CD16-CD158a+ and CD16-CD158a+ or CD16+NKB1+ and CD16-NKB1+ NK cells were not different in these donor groups. These findings suggest that the proportion of NK cells coexpressing CD16 and CD158b, but not CD158a nor NKB1, is influenced by zygosity for the HLA-Cw7 (NK1 ligand) haplotype. Since NK cells are involved in protection from virus infection, a reduced size of a ligand-specific NK subset in individuals homozygous for some HLA-B/C haplotypes may help explain their increased susceptibility to virus-induced diseases.

The MHC influences NK and NKT cell functions associated with immune abnormalities and lifespan

The lifespans of H-2 congenic mice differ significantly. The B10.AKM (H-2m) strain has a median survival time (MST) of 15 months, whereas the B10.BR (H-2k) strain has an MST of 24 months. It was previously shown that B10.AKM mice at 13-15 months of age have immunological function comparable to those of B10.BR mice at 22-26 months of age. These functions include: a low proliferative response, reduced levels of intracellular calcium release [Ca2+]i, and an increase in the frequency of memory helper T-cells (CD4+ CD44hiCD45RBlo). In this report similar deficiencies were demonstrated in B10.AKM mice at 2-4 months of age and show that activated spleen NK1.1+CD4+ T (NKT) cells from young B10.AKM mice produce a significantly higher level of IL-4 but a lower level of IFN-gamma as compared to NKT cells from B10.BR mice of the same age. Also, the cytotoxic activity of natural killer (NK) cells from spleens of young (2-4 months) as well as adult (12-16 months) B10.AKM mice is significantly lower (P < 0.01) than that of NK cells from B10.BR mice. These findings suggest that the NKT activity in young B10.AKM mice is a factor for the early onset of immune dysfunction leading to a shorter lifespan.

A YAC-based physical map of the mouse genome

A physical map of the mouse genome is an essential tool for both positional cloning and genomic sequencing in this key model system for biomedical research. Indeed, the construction of a mouse physical map with markers spaced at an average interval of 300 kb is one of the stated goals of the Human Genome Project. Here we report the results of a project at the Whitehead Institute/MIT Center for Genome Research to construct such a physical map of the mouse. We built the map by screening sequenced-tagged sites (STSs) against a large-insert yeast artificial chromosome (YAC) library and then integrating the STS-content information with a dense genetic map. The integrated map shows the location of 9,787 loci, providing landmarks with an average spacing of approximately 300 kb and affording YAC coverage of approximately 92% of the mouse genome. We also report the results of a project at the MRC UK Mouse Genome Centre targeted at chromosome X. The project produced a YAC-based map containing 619 loci (with 121 loci in common with the Whitehead map and 498 additional loci), providing especially dense coverage of this sex chromosome. The YAC-based physical map directly facilitates positional cloning of mouse mutations by providing ready access to most of the genome. More generally, use of this map in addition to a newly constructed radiation hybrid (RH) map provides a comprehensive framework for mouse genomic studies.

Irreversible inhibition of epidermal growth factor receptor tyrosine kinase with in vivo activity by N-[4-[(3-bromophenyl)amino]-6-quinazolinyl]-2-butynamide (CL-387,785)

It has been shown previously that 4-anilino quinazolines compete with the ability of ATP to bind the epidermal growth factor receptor (EGF-R), inhibit EGF-stimulated autophosphorylation of tyrosine residues in EGF-R, and block EGF-mediated growth. Since millimolar concentrations of ATP in cells could reduce the efficacy of 4-anilino quinazolines in cells and the activity of these compounds would not be sustained once they were removed from the body, we reasoned that irreversible inhibitors of EGF-R might improve the activity of this series of compounds in animals. Molecular modeling of the EGF-R kinase domain was used to design irreversible inhibitors. We herein describe one such inhibitor: N-[4-[(3-bromophenyl)amino]-6-quinazolinyl]2-butynamide, known as CL-387,785. This compound covalently bound to EGF-R. It also specifically inhibited kinase activity of the protein (IC50 = 370+/-120 pM), blocked EGF-stimulated autophosphorylation of the receptor in cells (ic50 approximately 5 nM), inhibited cell proliferation (IC50 = 31-125 nM) primarily in a cytostatic manner in cell lines that overexpress EGF-R or c-erbB-2, and profoundly blocked the growth of a tumor that overexpresses EGF-R in nude mice (when given orally at 80 mg/kg/day for 10 days, daily). We conclude that CL-387,785 is useful for studying the interaction of small molecules with EGF-R and may have clinical utility.

A comprehensive genetic map of the mouse genome

The availability of dense genetic linkage maps of mammalian genomes makes feasible a wide range of studies, including positional cloning of monogenic traits, genetic dissection of polygenic traits, construction of genome-wide physical maps, rapid marker-assisted construction of congenic strains, and evolutionary comparisons. We have been engaged for the past five years in a concerted effort to produce a dense genetic map of the laboratory mouse. Here we present the final report of this project. The map contains 7,377 genetic markers, consisting of 6,580 highly informative simple sequence length polymorphisms integrated with 797 restriction fragment length polymorphisms in mouse genes. The average spacing between markers is about 0.2 centimorgans or 400 kilobases.

c-Ha-ras gene mutation and activation precede pathological changes in DMBA-induced in vivo carcinogenesis

We have previously reported a stage-specific and sequential overexpression of the c-Ha-ras and c-erbB genes in 7, 12-dimethylbenzanthracene (DMBA)-induced in vivo carcinogenesis in hamster buccal pouch epithelium (HBPE). In this investigation, the immunoreactive protein product of the c-Ha-ras gene (p21 protein) was identified in HBPE cells, specifically in treated tissues and cultured cells established after 3 weeks of DMBA treatment. Microscopic examination did not show any histopathological changes in these tissues. The p21 protein was detected in a few selective cells, which were dispersed away from the more densely populated basal layer. The overexpression of the c-Ha-ras gene was accompanied by a point mutation of A----T in codon 61 (CAA), inducing an amino acid substitution from the wild-type glutamine to leucine in the peptide. The concurrent molecular modifications preceded any detectable histopathological changes. The cellular morphology and orientation in treated HBPE at this early stage was indistinguishable from the control tissue. Yet the genetic alterations, such as the point mutation and overexpression of the gene, were evident at the predysplastic stage. Amplification and overexpression of the second proto-oncogene, c-erbB, and its product, epidermal growth factor receptor (EGFR), were detected in HBPE cells at the later stages of extensive cell proliferation and invasion. By using double antibodies and two immunoreporter systems, we demonstrated overexpression of both c-Ha-ras and c-erbB genes in the same HBPE cells during this chemically induced in vivo carcinogenesis.

Cardioprotective effect of cromakalim (potassium channel opener) in isoproterenol induced myocardial infarction in rats

Animals pretreated with cromakalim (1 mg/kg,po) along with isoproterenol (85 mg/kg,sc) showed less myocardial degenerative changes on histopathological examinations when compared with those treated with isoproterenol alone. Cromakalim's beneficial effects on myocardium were in dose-dependent manner. Administration of cromakalim (po) lowered significantly the serum LDH and SGOT and depleted intracytoplasmic glycogen as demonstrated by periodic schiff staining procedure. Increase in blood clotting time was highly significant (P less than 0.001). The results suggest cardioprotective effect of cromakalim in isoproterenol induced myocardial infarction.

Role of ultraviolet radiation in the induction of melanocytic tumors in hairless mice following 7,12-dimethylbenz(a)anthracene application and ultraviolet irradiation

We examined the role of UVR (UV radiation) (UVA, 320-400 nm; UVB, 290-320 nm; and the combination of UVA and UVB) as a promoter in the induction of cutaneous melanoma. One hundred and seventy hairless mice (Skh-hr2), 6-8 weeks old, were treated in 8 groups: group I, DMBA [7,12-dimethylbenz(a)anthracene] plus UVA; group II, DMBA plus UVA plus UVB; group III, DMBA plus UVB; group IV, DMBA; group V, UVA; group VI, UVA plus UVB; group VII, UVB; group VIII, control. DMBA (0.5% solution) was applied once to promote the formation of dermal melanocytic nevus-like lesions while UVR treatments were conducted 3 times/week for 30 weeks. The mice were examined periodically for the development of multiple pigmented lesions, papillomas, squamous cell carcinomas, melanomas, and lymphomas. Treatment with DMBA plus UVA, DMBA plus UVB, and DMBA plus UVA plus UVB stimulated the development of multiple pigmented nevus-like lesions (85-100%) in mice of groups I, II, III, and IV. Upon necroscopy, 27-33% of animals in groups I, II, and III receiving UVR treatments developed clinically and histologically characterized melanomas. Treatment with DMBA alone did not produce melanomas. DMBA-treated animals in groups I, II, and III which received UVR treatments also developed lymphomas (21-50%). Animals treated with DMBA alone or those that received UVB or the combination of UVB plus UVA (without DMBA) developed only papillomas and squamous cell carcinomas (25-47%). Skin tumors were analyzed for the presence of point mutations in the ras gene. Polymerase chain reaction amplification of DNA and selective oligonucleotide hybridization revealed mutations in the 61st codon of the N-ras gene in the precursor nevus-like lesions and melanoma samples studied. This study suggests that UVR (both UVA and UVB) plays a role as a promoter in the stimulation of melanoma and lymphoma development in hairless mice.

Comparison of cellular protooncogene activation and transformation-related activity of human melanocytes and metastatic melanoma

Two cell lines (NH and HM1), established from patients with metastatic melanomas, were evaluated for the presence of activated cellular protooncogenes. Northern blot analysis demonstrated increased expression of the c-myc gene (from 9 to 14 times) in NH and HM1 cell lines by densitometric comparison with human melanocyte cell lines. Analysis of the expression of 13 additional cellular protooncogenes revealed either no detectable levels (c-fms, c-abl, v-src, c-erb A1, c-erb B, v-mos, TGF beta, and c-myb) or unaltered expression levels (cH-ras, N-ras, c-fos, and c-sis) in normal human melanocytes and metastatic melanomas. Elevated expression of the c-myc gene was also detected in two long-term cultured melanoma cell lines (RPMI 7951 and SKMEL-30). Analysis of c-myc expression by in situ hybridization in HM1 cells showed that expression was not localized to a sub-population of cycling cells and all cells were overexpressing c-myc mRNA. Differences in relative abundance of c-myc transcripts suggests a relationship with the ability of DNA from these cell lines to efficiently transform NIH 3T3 cells and form colonies on soft agar.

cHa-ras proto-oncogene. Amplification and overexpression in UV-B-induced mouse skin papillomas and carcinomas

The role of cellular proto-oncogene activation in shortwave UV light in the B range (UV-B)--induced skin carcinogenesis was investigated. Epidermal papillomas and carcinomas were induced on the depilated skin surface of Sencar mice with single-dose UV-B irradiation (7 x 10(4) J/m2). The tumors thus initiated were present in 18.8% of treated animals and were primarily benign papillomas, while a few (6 of 17) progressed to form squamous cell carcinomas. A 5- to 10-fold stimulation of cHa-ras gene expression in both papillomas and carcinomas was observed. Other cellular proto-oncogenes such as cKi-ras, c-myc, or c-fos specific messenger RNAs were not detected in these UV-B--induced skin tumors. Subsequent Southern blot analysis revealed a threefold to fivefold amplification of cHa-ras gene in skin papillomas and carcinomas. However, only the carcinoma and not the papilloma DNA induced foci in the classic NIH-3T3 transformation assay, suggesting that activation of cHa-ras gene alone is not sufficient to exhibit this phenotypic expression of transformed cells. The NIH-3T3 transformants exhibited (1) anchorage independent growth on soft agar, (2) tumor induction in athymic mice, and (3) overexpression and amplification of the cHa-ras gene. We propose that overexpression of a ras gene by gene amplification plays a role in the UV-B--induced skin carcinogenesis process.

Sequential expression and cooperative interaction of c-Ha-ras and c-erbB genes in in vivo chemical carcinogenesis

The level of expression of several cellular protooncogenes is examined at different stages of 7,12-dimethylbenzanthracene (DMBA)-induced tumor development in hamster buccal pouch epithelium (HBPE). Results presented demonstrate overexpression of c-Ha-ras gene at a very early stage of tumor development, and this elevated level of expression of the gene persists throughout the tumorigenesis process. The expression of the cellular protooncogene c-erbB, on the other hand, can be detected only after 8-10 weeks of DMBA treatment of the tissue and increases with the progression of the disease. The overexpression of c-erbB gene can be correlated with the stage of extensive proliferation and subsequent invasion of the HBPE cells into the underlying connective tissue. This sequential pattern of stage-specific expression of the two cellular protooncogenes can be observed in (i) treated tissues, (ii) stage-representative cultured cells, and (iii) NIH 3T3 transformants derived with DNA from HBPE cells. The low-level expression of c-myc and c-sis genes detected in control tissues remains unaffected, while c-fos gene activity cannot be detected at any stage of tumor development. The overexpression of c-Ha-ras gene alone in HBPE cells derived from tissues treated for 5 weeks (DM5) is not sufficient to induce tumors in athymic mice, whereas expression of c-Ha-ras and c-erbB genes at later stages of tumor development (DM10 and HCPC cells) induce histopathologically defined epithelial cell carcinoma in athymic mice within 2-3 weeks. The sequential overexpression of c-Ha-ras and c-erbB genes in a stage-specific manner and their cooperative interaction in the DMBA-induced in vivo oral carcinogenesis have been demonstrated.