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Zacarías-Fluck, et al identify and validate the Wnt receptor Fzd9 as a key effector of Myc-Wnt signaling cross-talk in a mouse model of Myc-driven pancreatic insulinomas., The huge cadre of genes regulated by Myc has obstructed the identification of critical effectors that are essential for Myc-driven tumorigenesis. Here, we describe how only the lack of the receptor Fzd9, previously identified as a Myc transcriptional target, impairs sustained tumor expansion and β-cell dedifferentiation in a mouse model of Myc-driven insulinoma, allows pancreatic islets to maintain their physiological structure and affects Myc-related global gene expression. Importantly, Wnt signaling inhibition in Fzd9-competent mice largely recapitulates the suppression of proliferation caused by Fzd9 deficiency upon Myc activation. Together, our results indicate that the Wnt signaling receptor Fzd9 is essential for Myc-induced tumorigenesis in pancreatic islets.

A field study was established to evaluate symptoms, growth, yield, and nut quality of walnut trees subjected to multiple exposures of simulated bispyribac-sodium drift. Nut yield the year following simulated drift treatment was also evaluated because tissue differentiation for future fruiting position occurs in the prior season. Bispyribac-sodium was applied four times, at weekly intervals, at 0.5% and 3% of the use rate in rice (45 g ai ha-1). Injury from the 0.5% rate exceeded 5% after three applications. In general, the severity of the symptoms peaked 14 d after last application (23% and 40% injury for 0.5% and 3% rate, respectively) and subsequently remained nearly constant over the duration of the study. Growth of shoots treated with the 0.5% rate was initially delayed during the treatment regime but recovered after treatments ended; however, walnut shoots exposed to the higher rate had fewer internodes than nontreated trees at the end of the season. No measurable reduction in walnut yield or average nut weight either in the year of exposure or in the subsequent year was observed. However, both rates negatively affected walnut kernel color in the year of exposure.Nomenclature: Bispyribac-sodium; rice, Oryza sativa L.; walnut, Juglans regia L.

A field study was established to study symptoms, growth and yield of 2-year-old walnut trees exposure to simulated drift of several herbicides commonly used in rice production. Bispyribac-sodium, bensulfuron-methyl, and propanil were applied at four rates representing 0.5%, 1%, 3% and 10% of the normal use rate in rice (45, 70, and 6725 g ai ha-1, for the three herbicides respectively). Symptoms started to appear approximately 7 days after application (DAT) and peaked 28 DAT. At that time, bispyribac-sodium caused greater injury at low drift rates (6% and 15% visual injury for 0.5% and 1% rate, respectively) compared to bensulfuronmethyl and propanil. Bispyribac-sodium also appeared to slow walnut shoot elongation compared to nontreated trees; however, no yield reductions were observed either in the year after drift exposure. The effect of bispyribac-sodium simulated drift on the yield and nut quality in the year of drift exposure was evaluated in a separate study on 3-year-old walnut trees. While no yield or nut quality reductions were observed, a linear correlation between rate of bispyribac-sodium and color, an important quality factor, was found: higher herbicide rates tended to be associated with darker kernel color. Bispyribac-sodium may damage nearby walnut orchards if drifted at significant amounts. However, it is unlikely that in a field situation bispyribac-sodium would drift at high enough levels to cause the symptoms observed from the 10% use rates in this study.Nomenclature: bispyribac-sodium; bensulfuron-methyl; propanil; rice, Oryza sativa L.; walnut, Juglans regia L.

Although lymphomas account for almost half of blood-derived cancers that are diagnosed each year, the causes of new cases are poorly understood, as reflected by the relatively few risk factors established. Galectin-1, an immunoregulatory ß-galactoside-binding protein, has been widely associated with tumor-immune escape. The aim of the present work was to study the relationship between tumor growth rate, aggressiveness, and response to cyclophosphamide (Cy) therapy with regard to Gal-1 expression in murine T-cell lymphoma models. By means of a disruptive selection process for tumor growth rate, we generated two lymphoma variants from a parental T-cell lymphoma, which have unique characteristics in terms of tumor growth rate, spontaneous regression, metastatic capacity, Gal-1 expression and sensitivity to Cy therapy. Here, we show that Gal-1 expression strongly correlates with tumor growth rate, metastatic capacity and response to single-dose Cy therapy in T-cell lymphoma models; this association might have important consequences for evaluating prognosis and treatments of this type of tumors.

Myc encodes for a transcription factor deregulated in the vast majority of human cancers, mainly by amplification or constant upstream oncogenic signaling. Previous work from our laboratory showed that targeting Myc by transgenic expression of the Myc inhibitor Omomyc is an effective strategy to inhibit tumor progression and cause tumor regression in a wide array of mouse cancer models, without any evidence of toxicity in normal tissues. Our goal now is to assess whether Myc inhibition can be an effective approach to treat melanoma, the most dangerous form of skin cancer. For this purpose, we transfected human melanoma cell lines with a doxycycline-dependent vector expressing Omomyc-RFP and characterized the effect of Myc inhibition on proliferation and colony formation, as well as the expression of different cell cycle related proteins. We observed that Omomyc significantly reduced proliferation of a wide variety of cell lines, regardless of their driving mutations. In p53 wild type cells, Omomyc expression was accompanied by p53 stabilization and concomitant p21 upregulation, and in BRaf or NF1 mutated melanoma cells, by downregulation of cyclin D1. In order to elucidate the mechanism of action underlying this anti-tumorigenic effect, we performed a microarray analysis of A375 melanoma cells in the presence or absence of Omomyc-RFP expression. This analysis showed that Omomyc affected genome-wide gene expression. More in detail, Gene Set Enrichment Analysis showed that Omomyc significantly blunts the expression of both Myc and E2F targets, as well as RNA biogenesis, DNA replication and different cell cycle checkpoints, among many others relevant gene sets. Importantly, Omomyc significantly reduced the expression of genes related to melanoma metastases. Finally, in order to validate Omomyc therapeutic impact in vivo, A375 and SkMel147 cells were s.c. implanted into nude mice and the effect of Omomyc expression on tumor progression was evaluated. Our results show that Omomyc expression significantly impairs the growth of both cell lines, increasing the survival of tumor-bearing mice. These results combined clearly show that Omomyc-mediated Myc inhibition is an effective means to impair melanoma progression, by directly targeting Myc, inhibiting cell cycle and decreasing melanoma aggressiveness. Citation Format: Mariano F. Zacarias-Fluck, Génesis Martín, Daniel Massó-Vallés, Laia Foradada, Jonathan R. Whitfield, Marie-Eve Beaulieu, Laura Soucek. Myc inhibition by Omomyc impairs melanoma growth and progression through genome-wide gene expression reprogramming [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3351.

Accumulating evidence indicates that a dynamic cross-talk between tumors and the immune system can regulate tumor growth and metastasis. Increased understanding of the biochemical nature of tumor antigens and the molecular mechanisms responsible for innate and adaptive immune cell activation has revolutionized the fields of tumor immunology and immunotherapy. Both the protective effects of the immune system against tumor cells (immunosurveillance) and the evasion of tumor cells from immune attack (tumor-immune escape) have led to the concept of cancer immunoediting, a proposal which infers that a bidirectional interaction between tumor and inflammatory/regulatory cells is ultimately responsible for orchestrating the immunosuppressive network at the tumor site. In this context, a major challenge is the potentiation or redirection of tumor antigen-specific immune responses. The success in reaching this goal is highly dependent on an improved understanding of the interactions and mechanisms operating during the different phases of the cancer immunoediting process. In this review, we discuss the multiple defense and counterattack strategies that tumors have devised in order to evade immune attack and to thwart the effectiveness of several immunotherapeutic approaches.

In recent years, one of the most important insights into tumor immunity was provided by the identification of negative regulatory pathways and immune escape strategies that greatly influence the magnitude of antitumor responses. Galectin-1 (Gal-1), a member of a family of highly conserved beta-galactoside-binding proteins, has been recently shown to contribute to tumor cell evasion of immune responses by modulating survival and differentiation of effector T cells. However, there is still scarce information about the regulation of Gal-1 expression and function in vivo. Here we show that administration of a single low-dose cyclophosphamide (Cy), which is capable of restraining metastasis in the rat lymphoma model L-TACB, can also influence Gal-1 expression in primary tumor, metastasis, and spleen cells and modulate the effects of this protein on T cell survival. A time-course study revealed a positive correlation between Gal-1 expression and tumor volume in primary tumor cells. Conversely, Gal-1 expression was significantly reduced in spleen cells and lymph node metastasis throughout the period studied. Interestingly, cyclophosphamide treatment was capable of restoring the basal levels of Gal-1 expression in primary tumors and spleens. In addition, this antimetastatic agent rendered spleen T cells from tumor-bearing animals resistant to Gal-1-induced cell death. Our results suggest that, in addition to other well-known functions of cyclophosphamide, this immunomodulatory agent may also modulate Gal-1 expression and function during tumor growth and metastasis with critical implications for tumor-immune escape and immunotherapy.

Deregulation of the MYC oncoprotein promotes tumorigenesis in most, if not all, cancers and is often associated with poor prognosis. However, targeting MYC has long been considered impossible based on the assumption that it would cause catastrophic side effects in normal tissues. Despite this general preconceived notion, we showed that MYC inhibition exerts extraordinary therapeutic impact in various genetic mouse models of cancer, and causes only mild, well-tolerated and reversible side effects. For these studies we employed the systemic and conditional expression of a dominant negative of MYC, called Omomyc, which we designed and validated, and that can inhibit MYC transactivation function both in vitro and in vivo. To date, Omomyc has only been considered a proof of principle, with any potential clinical application limited to gene therapy. Here we actually show that the 11 kDa Omomyc polypeptide spontaneously transduces into cancer cells, demonstrating unexpected cell-penetrating ability. Once inside the nuclei, the polypeptide effectively blocks MYC binding to its target DNA sites, interfering with MYC transcriptional regulation and halting cell proliferation. Moreover, intranasal (i.n.) administration of the Omomyc polypeptide in mice results in its rapid and persistent distribution to lungs, as well as to other organs (i.e. intestine, liver, kidneys and brain). Importantly, i.n. treatment of mice bearing either Non-Small-Cell-Lung-Cancer (NSCLC) or glioblastoma (GBM) with the Omomyc cell-penetrating peptide (OmomycCPP) significantly reduces tumor burden compared to their control counterparts. Notably, tumor regression is accompanied by significant reprogramming of the tumor microenvironment and tumor immune response. In summary, our data indicate that this novel generation of polypeptides represents a new opportunity to potentially inhibit MYC pharmacologically in a variety of malignant diseases. Citation Format: Marie-eve Beaulieu, Toni Jauset, Daniel Massó-Vallés, Peter Rahl, Sandra Martinez-Martin, Loika Maltais, Mariano F. Zacarias-Fluck, Silvia Casacuberta, Erika Serrano del Pozo, Christopher Fiore, Laia Foradada, Matthew Guenther, Eduardo Romero Sanz, Marta Oteo Vives, Cynthia Tremblay, Martin Montagne, Miguel Ángel Morcillo Alonso, Jonathan R. Whitfield, Pierre Lavigne, Laura Soucek. Preclinical validation of an Omomyc cell-penetrating peptide as a viable anti-Myc therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2167. doi:10.1158/1538-7445.AM2017-2167

La inmunoedición del cáncer es un proceso dinámico compuesto de tres fases: eliminación (EL), equilibrio (EQ) y escape (ES) que abarca las posibles funciones protectoras del huésped y de esculpir el tumor del sistema inmunitario durante el desarrollo del tumor. Los modelos animales son herramientas útiles para estudiar enfermedades como el cáncer. El presente estudio fue diseñado para caracterizar la interacción entre el adenocarcinoma mamario M-406 y CBi, CBi - y CBi / L líneas de ratones endogámic Cancer immunoediting is a dynamic process composed of three phases: elimination (EL), equilibrium (EQ) and escape (ES) that encompasses the potential host-protective and tumor-sculpting functions of the immune system throughout tumor development. Animal models are useful tools for studying diseases such as cancer. The present study was designed to characterize the interaction between mammary adenocarcinoma M-406 and CBi, CBi− and CBi/L inbred mice lines. Fil: Pagura, Lucas. Facultad de Ciencias Bioquímicas y Farmacéuticas. Universidad Nacional de Rosario; Rosario; Argentina Fil: Cáceres, Juan Manuel. Facultad de Ciencias Médicas. Universidad Nacional de Rosario; Rosario; Argentina Fil: Cardinali, Albertina. Facultad de Ciencias Médicas. Universidad Nacional de Rosario; Rosario; Argentina Fil: Scharovsky, Graciela Olga. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; Argentina Fil: Di Masso, Ricardo José. Facultad de Ciencias Médicas. Universidad Nacional de Rosario; Rosario; Argentina Fil: Zacarias-Fluck, Mariano. Preclinical Research. Vall d’Hebron Institute of Oncology (VHIO); Barcelona; Spain Fil: Rico, María José. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; Argentina Fil: Rozados, Viviana R. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; Argentina

Senescence, a terminal cell proliferation arrest, can be triggered by oncogenes. Oncogene-induced senescence is classically considered a tumor defense barrier. However, several findings show that, under certain circumstances, senescent cells may favor tumor progression because of their secretory phenotype. Here, we show that the expression in different breast epithelial cell lines of p95HER2, a constitutively active fragment of the tyrosine kinase receptor HER2, results in either increased proliferation or senescence. In senescent cells, p95HER2 elicits a secretome enriched in proteases, cytokines, and growth factors. This secretory phenotype is not a mere consequence of the senescence status and requires continuous HER2 signaling to be maintained. Underscoring the functional relevance of the p95HER2-induced senescence secretome, we show that p95HER2-induced senescent cells promote metastasis in vivo in a non–cell-autonomous manner. Cancer Res; 73(1); 450–8. ©2012 AACR.

BACKGROUND Oncogene-induced senescence (OIS) is a tumor suppressor mechanism. However, senescent cells remain viable and display a distinct secretome (also known as senescence-associated secretory phenotype [SASP] or senescence messaging secretome, [SMS]) that, paradoxically, includes protumorigenic factors. OIS can be triggered by ectopic overexpression of HER2, a receptor tyrosine kinase and the driving oncogene in a subtype of human breast cancer. However, cellular senescence has not been characterized in HER2-positive tumors. METHODS Using an approach based on their inability to proliferate, we isolated naturally occurring senescent cells from a variety of tumor models including HER2-positive cells, transgenic mice (n = 3), and patient-derived xenografts (PDXs) (n = 6 mice per group from one PDX derived from one patient). Using different biochemical and cell biological techniques, we characterized the secretome of these senescent cells. All statistical tests were two-sided. RESULTS We found that senescent cells arise constantly in different models of advanced breast cancers overexpressing HER2 and constitute approximately 5% of tumor cells. In these models, IL-6 and other cytokines were expressed mainly, if not exclusively, by the naturally occurring senescent cells (95.1% and 45.0% of HCC1954 cells and cells from a HER2-positive PDX expressing a senescent marker expressed IL-6, respectively). Furthermore, inhibition of IL-6 impaired the growth of the HER2-positive PDX (mean tumor volume at day 101, control vs anti-huIL-6 treated, 332.2mm(3) [95% confidence interval {CI} = 216.6 to 449.8] vs 114.4mm(3) [95% CI = 12.79 to 216.0], P = .005). CONCLUSIONS Senescent cells can contribute to the growth of tumors by providing cytokines not expressed by proliferating cells, but required by these to thrive.

Breast cancer is a complex, multifactor disease that affects about 10% of women in industrialized countries. Inbred mice models provide an interesting tool for identifying genes that control susceptibility to breast cancer. CBi- mice was artificially selected for body conformation from CBi. The mammary adenocarcinoma M-406 developed spontaneously in CBi female mouse and is maintained in vivo in mice of the same line. When CBi- mice are s.c. challenged with M-406 they show 100% take and 100% regression (resistance). In contrast, the tumor grows exponentially (susceptibility) in CBi mice. The aim of this study was to characterize the tumor behavior in both F1 reciprocal hybrids [(CBi × CBi-) and (CBi- × CBi) n=48], and in the four F2 combinations between them: F2A [(CBi- × CBi) × (CBi- × CBi)]; F2B [(CBi- × CBi) × (CBi × CBi-)]; F2C [(CBi × CBi-) X (CBi- × CBi)] and F2D [(CBi × CBi-) X (CBi × CBi-)] n=185. Adult female and male mice where challenged s.c. with M-406 by trocar, three tumor fragments (∼8 × 105cells). Tumors were measured three times/week and tumor volumes were calculated as follows: V = 0.4 (ab2), where V = volume (mm3), a = largest diameter (mm) and b = smallest diameter (mm). Tumor volume vs time data were fit to an exponential growth model Vt: S*e[k*t]. M-406 grew exponentially in 45/48 F1 mice. Non statistical differences were found in tumor growth rates between sexes on the reciprocal F1s. Significant differences in tumor volume doubling time (TvDT = 0.69/k) were observed between sexes in two of the four F2 combinations: F2A [females: 5.34 ± 0.44; males: 4.27 ± 0.26; t=2.154, P=0.038] and F2D [females: 4.04 ± 0.14; males: 4.85 ± 0.38; t=1.804, P=0.041]. When comparing females TvDT, F2D had a faster growth rate than F2A (P=0.0097), while non statistical differences were evident in males (P = 0.102). It is concluded that susceptibility to M-406 in CBi mice is inherited as a dominant trait. Genes involved in susceptibility inheritance would be autosomic, as the tumor behaviour in both F1 reciprocal hybrids is similar. The analysis of F2 alternative combinations allowed the identification of maternal effect as well as sexual dimorphism influencing tumor growth. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2390. doi:10.1158/1538-7445.AM2011-2390

Mouse aggregated IgG, when continuously present in cultures of mouse spleen cells immunized with sheep erythrocytes, causes a dose dependent inhibition of the generation of plaque forming cells with a maximum of about 90% at 400 μg IgG/culture. Unaggregated IgG induces a similar inhibition, whereas treatment with mouse albumin or F (ab 1 ) 2 , under the same conditions, does not affect the generation of plaque forming cells. It has been reported that unaggregated IgG binds poorly to Fc receptors of B lymphocytes and thus should not be expected to inhibit PFC generation if the effect is at the level of B lymphocyte Fc receptors. Competitive binding experiments were carried out and showed that aggregated and unaggregated IgG compete similarly with 125 I-labeled aggregated IgG for binding to Fc receptors of mouse spleen cells. The same inhibition of PFC can be induced by aggregated IgG in cultures of B lymphocytes immunized with the T-independent antigen DNP-Ficoll. When IgG is absorbed extensively with sheep erythrocytes and added to cultures immunized with sheep erythrocytes, PFC generation is inhibited to a level comparable to that of nonabsorbed IgG. These results suggest that IgG binding to Fc receptors leads to a severe inhibition of the induction of PFC by both T-dependent and T-independent antigens. This and other work from our laboratory indicate that this effect may be at the level of B lymphocyte Fc receptors. Taken together with reports from several laboratories, the data presented here suggest that Fc receptors may have a regulatory role on the activation of B lymphocytes by antigens or mitogens.

The peripheral blood lymphocytes of a patient with clinically diagnosed chronic lymphocytic leukemia were studied morphologically and functionally. They appeared to be classical small lymphocytes with no features of Sezary cells. Only 1% of the cells stained positively with fluorescent anti Ig sera or with aggregated Ig, and 5% formed rosettes with sheep erythrocytes coated with antibody and human complement (EAC). On the other hand, 95% of the lymphocytes formed spontaneous rosettes with sheep erythrocytes, and 95% or greater were killed by antiserum raised to T lymphocytes. The proliferative responses also indicated that these cells reacted as T cells. It is interesting that while the cells from this patient stimulated very well in a mixed lymphocyte reaction, they were not stimulated by the lymphocytes of three individuals. Our results indicate that this is a T cell leukemia, and the results of the MLR seem to point that the cell proliferates as a clone.

The analogue of phenylalanine, β-3-thienylalanine, depresses severely the primary and secondary immune response to sheep erythrocytes in mice when administered for a few days immediately before and after each injection of antigen. For this immunosuppression to occur, animals must be maintained on a phenylalanine-free diet during the times of drug injection since dietary phenylalanine will restore anamnestic response. With these experimental conditions, the number of direct and indirect plaque-forming cells is greatly reduced during immune responses. The finding that marked immunosuppression can be obtained with a very short drug and diet treatment points to a potential usefullness of the analogue as a powerful immunosuppressant.

Avian peripheral blood and embryonic spleen cells were prepared for cell flow cytometry. The Ortho Spectrum III was the flow cytometer used in these experiments. The major objectives were to identify the location of lymphocytes and granulocytes in the cytogram displayed by flow cytometry, to develop a technique which would allow the collection of granulocytes relatively free of other cell types and to characterize the cell cycle within these cell populations. The cytogram of fresh avian cells developed in the Ortho Spectrum III revealed three characteristic cell clusters. Peripheral blood or embryonic spleen cells were separated on a Ficoll-Hypaque double density gradients into two distinct layers and a pellet. Light microscopic examination revealed the top layer of cells to be primarily lymphocytes while the middle layer of cells was granulocytes. Presentation of the cells from these layers to the Ortho Spectrum III revealed that granulocytes made up Cluster 3 while lymphocytes were included in the other clusters. The Ortho Spectrum III was employed to determine the presence of G1 (pre-DNA synthesis), S (DNA synthesis), and G2/M (post-DNA synthesis and mitosis) phases of cells in Clusters 1 and 2 and Cluster 3. While all the cells from peripheral blood were in G1, the embryonic spleen revealed cells in G1, S and G2/M in both Clusters 1 and 2 and Cluster 3.

Publisher Summary This chapter provides an overview of the role of some membrane-related events in B lymphocyte activation by antigens. The interaction of antigenic determinants with B lymphocyte surface receptors is necessary to initiate the differentiation of progeny cells to plasma cells. Antigen stimulated lymphocytes exhibit several early changes, such as the movement and redistribution of antigen–receptor complexes and changes in membrane ion flux, in intracellular cyclic nucleotides, and in the microfilament–microtubule system. An interaction of antigen with SMIg followed by the redistribution of the complex and a second interaction with Fc receptors are events necessary for the activation of B lymphocytes to produce an immune response. This antigen binds to 1% of spleen cells with its antigenic determinant and has been shown to bind SMIg. It is capable of eliciting a better immune response in the absence of macrophages and T cells than when these are present. These events may be important in providing the signal transduction for lymphocyte activation. Macrophages and T and B lymphocytes have Fc receptors that made it possible that the suppression of DPFC could be at the level of one or several of the interactions occurring in a complex system. This chapter describes studies conducted to better characterize the DPFC response to DNP-Ficoll and to examine the suppressive effect of aggregated IgG on this response.

The synthesis of immunoglobulin consists of a complex series of cellular and molecular reactions beginning soon after the injection of a specific antigen. It is established with some certainty that antigen, following administration, is taken up by macrophages and processed by these cells. A stimulus is then transmitted in a still undetermined manner to immunocompetent, undifferentiated reticular cells. These begin dividing very rapidly and give rise to differentiated lymphoid cells which are the main antibody producers. The serum antibody titer begins to rise around the third day after primary immunization, reaches a peak by the end of the first week, and then declines slowly. A second injection of antigen is followed by a more rapid rise and a slower decline of antibody titer [1–4].

A 52 yr old Caucasian female (F. E.) had hemolytic anemia, a leukemoid reaction, and fatal sepsis due to Escherichia coli. Her leukocytes ingested bacteria normally but did not kill catalase positive Staphylococcus aureus, Escherichia coli, and Serratia marcescens. An H(2)O(2)-producing bacterium, Streptococcus faecalis, was killed normally. Granule myeloperoxidase, acid and alkaline phosphatase, and beta glucuronidase activities were normal, and these enzymes shifted normally to the phagocyte vacuole (light and electron microscopy). Intravacuolar reduction of nitroblue tetrazolium did not occur. Moreover, only minimal quantities of H(2)O(2) were generated, and the hexose monophosphate shunt (HMPS) was not stimulated during phagocytosis. These observations suggested the diagnosis of chronic granulomatous disease. However, in contrast to control and chronic granulomatous disease leukocytes, glucose-6-phosphate dehydrogenase activity was completely absent in F. E. leukocytes whereas NADH oxidase and NADPH oxidase activities were both normal. Unlike chronic granulomatous disease, methylene blue did not stimulate the hexose monophosphate shunt in F. E. cells. Thus, F. E. and chronic granulomatous disease leukocytes appear to share certain metabolic and bactericidal defects, but the metabolic basis of the abnormality differs. Chronic granulomatous disease cells lack oxidase activity which produces H(2)O(2); F. E. cells had normal levels of oxidase activity but failed to produce NADPH due to complete glucose-6-phosphate dehydrogenase deficiency. These data indicate that a complete absence of leukocyte glucose-6-phosphate dehydrogenase with defective hexose monophosphate shunt activity is associated with low H(2)O(2) production and inadequate bactericidal activity, and further suggest an important role for NADPH in the production of H(2)O(2) in human granulocytes.

SummaryAntibody formation, which is inhibited by 500 r of total body x-irradiation into the rat, can be restored partially by spleen homogenates injected soon after irradiation. No striking difference in the degree of recovery is observed when spleen cells from rats stimulated earlier with a different antigen are used in place of “normal” spleen cells.

The analogue of phenylalanine, β-3-thienylalanine (β-3-TA), inhibits the primary and secondary immune responses to sheep red blood cells in CBA mice fed with phenylalanine-free diet. The optimal dose of β-3-TA needed to obtain maximum immunosuppression with minimal toxicity is 250 mg per kg per day. The drug is maximally effective when administered for 7 days, beginning 2 days prior to primary immunization. With these experimental conditions, the antibody titers and the numbers of direct and indirect plaque-forming cells are greatly reduced during the primary and the secondary immune response.

The pleiotropic cytokine IL-6 accelerates the progression of breast cancer in a variety of preclinical models through the activation of the STAT3 (signal transducer and activator of transcription 3) signaling pathway. However, the proportion of breast cancers sensitive to anti-IL-6 therapies is not known. This study evaluates the efficacy of anti-IL-6 therapies using breast cancer patient derived xenografts (PDXs). During the generation of our collection of PDXs, we showed that the successful engraftment of tumor tissue in immunodeficient mice correlates with bad prognosis. Four PDXs out of six were resistant to anti-IL-6 therapies and the expression of IL-6, its receptor or the levels of phospho-STAT3 (the active form of the signal transducer) did not correlate with sensitivity. Using cell cultures established from the PDXs as well as samples from in vivo treatments, we showed that only tumors in which the activation of STAT3 depends on IL-6 respond to the blocking antibodies. Our results indicate that only a fraction of breast tumors are responsive to anti-IL-6 therapies. In order to identify responsive tumors, a functional assay to determine the dependence of STAT3 activation on IL-6 should be performed.

The production of agglutinins to Salmonella typhi was studied in the opossum embryo in the period immediately before and after the development of thymic and lymph node lymphoid tissue. Antibody was found only in embryos older than 8 days which corresponds to an 8- to 10-week human embryo in terms of organogenesis and is the earliest stage at which antibody production has been recorded.

We compared T lymphocyte subsets of 14 normal term newborns (cord blood) to those of 8 children with gram negative sepsis. Six patients were

Background Severe burn is a systemic illness often complicated by sepsis. Kidney is one of the organs invariably affected, and proteinuria is a constant clinical finding. We studied the relationships between proteinuria and patient outcome, severity of renal dysfunction and systemic inflammatory state in burns patients who developed sepsis-associated acute renal failure (ARF). We then tested the hypothesis that plasma in these patients induces apoptosis and functional alterations that could account for proteinuria and severity of renal dysfunction in tubular cells and podocytes. Methods We studied the correlation between proteinuria and indexes of systemic inflammation or renal function prospectively in 19 severe burns patients with septic shock and ARF, and we evaluated the effect of plasma on apoptosis, polarity and functional alterations in cultured human tubular cells and podocytes. As controls, we collected plasma from 10 burns patients with septic shock but without ARF, 10 burns patients with septic shock and ARF, 10 non-burns patients with septic shock without ARF, 10 chronic uremic patients and 10 healthy volunteers. Results Septic burns patients with ARF presented a severe proteinuria that correlated to outcome, glomerular (creatinine/urea clearance) and tubular (fractional excretion of sodium and potassium) functional impairment and systemic inflammation (white blood cell (WBC) and platelet counts). Plasma from these patients induced a pro-apoptotic effect in tubular cells and podocytes that correlated with the extent of proteinuria. Plasma-induced apoptosis was significantly higher in septic severe burns patients with ARF with respect to those without ARF or with septic shock without burns. Moreover, plasma from septic burns patients induced an alteration of polarity in tubular cells, as well as reduced expression of the tight junction protein ZO-1 and of the endocytic receptor megalin. In podocytes, plasma from septic burns patients increased permeability to albumin and decreased the expression of the slit diaphragm protein nephrin. Conclusion Plasma from burns patients with sepsis-associated ARF contains factors that affect the function and survival of tubular cells and podocytes. These factors are likely to be involved in the pathogenesis of acute tubular injury and proteinuria, which is a negative prognostic factor and an index of renal involvement in the systemic inflammatory reaction.