Granulocyte macrophage colony-stimulating factor: current practice and novel approaches

Pathogenesis-driven treatment of primary pulmonary alveolar proteinosis

Pulmonary alveolar proteinosis (PAP) is a syndrome that results from the accumulation of lipoproteinaceous material in the alveolar space. According to the underlying pathogenetic mechanisms, three different forms have been identified, namely primary, secondary and congenital. Primary PAP is caused by disruption of granulocyte-macrophage colony-stimulating factor (GM-CSF) signalling due to the presence of neutralising autoantibodies (autoimmune PAP) or GM-CSF receptor genetic defects (hereditary PAP), which results in dysfunctional alveolar macrophages with reduced phagocytic clearance of particles, cholesterol and surfactant. The serum level of GM-CSF autoantibody is the only disease-specific biomarker of autoimmune PAP, although it does not correlate with disease severity. In PAP patients with normal serum GM-CSF autoantibody levels, elevated serum GM-CSF levels is highly suspicious for hereditary PAP. Several biomarkers have been correlated with disease severity, although they are not specific for PAP. These include lactate dehydrogenase, cytokeratin 19 fragment 21.1, carcinoembryonic antigen, neuron-specific enolase, surfactant proteins, Krebs von Lungen 6, chitinase-3-like protein 1 and monocyte chemotactic proteins. Finally, increased awareness of the disease mechanisms has led to the development of pathogenesis-based treatments, such as GM-CSF augmentation and cholesterol-targeting therapies.

Deciphering the antitumoral potential of the bioactive metabolites from medicinal mushroom Inonotus obliquus

ETHNOPHARMACOLOGICAL RELEVANCE

The crude extracts of the medicinal mushroom Inonotus obliquus have been used as an effective traditional medicine to treat malicious tumors, gastritis, gastric ulcers, and other inflammatory conditions in Russia and most Baltic countries.

AIM OF THIS REVIEW

Deciphering the antitumoral potential of the bioactive metabolites from I. obliquus and addressing its possibility to be used as effective agents for tumor treatment, restoration of compromised immunity and protection of gastrointestinal damage caused by chemotherapy.

MATERIALS AND METHODS

We analysed the current achievements and dilemma in tumor chemo- or immunotherapy. In this context, we searched the published literatures on I. obliquus covering from 1990 to 2020, and summarized the activities of antitumor, antioxidation, and immunomodulation by the polysaccharides, triterpenoids, small phenolic compounds, and hispidin polyphenols. By comparing the merits and shortcomings of current and traditional methodology for tumor treatment, we further addressed feasibility for the use of I. obliquus as an effective natural drug for tumor treatment and prevention.

RESULTS

The diverse bioactive metabolites confer I. obliquus great potential to inhibit tumor growth and metastasis. Its antitumor activities are achieved either through suppressing multiple oncogenic signals including but not limited to the activation of NF-κB and FAK, and the expression of RhoA/MMP-9 via ERK1/2 and PI3K/Akt signaling pathway. The antitumor activities can also be achieved by inhibiting tyrosinase activity via PAK1-dependent signaling pathway or altering lysosomal membrane permeabilization through blocking tubulin polymerization and/or disturbing energy metabolism through LKB1/AMPK pathway. In addition, the metabolites from I. obliquus also harbour the potentials to reverse MDR either through selective inhibition on P-gp/ABCB1 or MRP1/ABCC1 proteins or the induction of G2/M checkpoint arrest in tumor cells of chemoresistant phenotypes mediated by Nox/ROS/NF-kB/STAT3 signaling pathway. In addition to the eminent effects in tumor inhibition, the metabolites in I. obliquus also exhibit immunomodulatory potential to restore the compromised immunity and protect against ulcerative damage of GI tract caused by chemotherapy.

CONCLUSIONS

I. obliquus possesses the potential to reduce incidence of tumorigenesis in healthy people. For those whose complete remission has been achieved by chemotherapy, administration of the fungus will inhibit the activation of upstream oncogenic signals and thereby prevent metastasis; for those who are in the process of chemotherapy administration of the fungus will not only chemosensitize the tumor cells and thereby increasing the chemotherapeutic effects, but also help to restore the compromised immunity and protect against ulcerative GI tract damage and other side-effects induced by chemotherapy.

Inflammation Alters the Secretome and Immunomodulatory Properties of Human Skin-Derived Precursor Cells

Human skin-derived precursors (SKP) represent a group of somatic stem/precursor cells that reside in dermal skin throughout life that harbor clinical potential. SKP have a high self-renewal capacity, the ability to differentiate into multiple cell types and low immunogenicity, rendering them key candidates for allogeneic cell-based, off-the-shelf therapy. However, potential clinical application of allogeneic SKP requires that these cells retain their therapeutic properties under all circumstances and, in particular, in the presence of an inflammation state. Therefore, in this study, we investigated the impact of pro-inflammatory stimulation on the secretome and immunosuppressive properties of SKP. We demonstrated that pro-inflammatory stimulation of SKP significantly changes their expression and the secretion profile of chemo/cytokines and growth factors. Most importantly, we observed that pro-inflammatory stimulated SKP were still able to suppress the graft-versus-host response when cotransplanted with human PBMC in severe-combined immune deficient (SCID) mice, albeit to a much lesser extent than unstimulated SKP. Altogether, this study demonstrates that an inflammatory microenvironment has a significant impact on the immunological properties of SKP. These alterations need to be taken into account when developing allogeneic SKP-based therapies.

Acquired resistance to cancer immunotherapy: Role of tumor-mediated immunosuppression

In the tumor microenvironment (TME), tumor cells are constantly evolving to reduce neoantigen generation and the mutational burden to escape the anti-tumor response. This will lower tumor reactivity to the adaptive immune response and give rise to tumor intrinsic factors, such as altered expression of immune regulatory molecules on tumor cells. Tumor-extrinsic factors, such as immunosuppressive cells, soluble suppressive molecules or inhibitory receptors expressed by immune cells will alter the composition and activity of tumor-infiltrating lymphocytes (TILs) (by increasing T regulatory cells:T effector cells ratio and inhibiting T effector cell function) and promote tumor growth and metastasis. Together, these factors limit the response rates and clinical outcomes to a particular cancer therapy. Within the TME, the cross-talks between immune and non-immune cells result in the generation of positive feedback loops, which augment immunosuppression and support tumor growth and survival (termed as tumor-mediated immunosuppression). Cancer immunotherapies, such as immune checkpoint inhibitors (ICIs) and adoptive cell transfer (ACT), have shown therapeutic efficacy in hematologic cancers and different types of solid tumors. However, achieving durable response rates in some cancer patients remains a challenge as a result of acquired resistance and tumor immune evasion. This could be driven by the cellular and molecular suppressive network within the TME or due to the loss of tumor antigens. In this review, we describe the contribution of the immunosuppressive cellular and molecular tumor network to the development of acquired resistance against cancer immunotherapies. We also discuss potential combined therapeutic strategies which could help to overcome such resistance against cancer immunotherapies, and to enhance anti-tumor immune responses and improve clinical outcomes in patients.

Granulocyte-macrophage colony-stimulating factor neuroprotective activities in Alzheimer's disease mice

We investigated the effects of granulocyte-macrophage colony stimulating factor (GM-CSF) on behavioral and pathological outcomes in Alzheimer's disease (AD) and non-transgenic mice. GM-CSF treatment in AD mice reduced brain amyloidosis, increased plasma Aβ, and rescued cognitive impairment with increased hippocampal expression of calbindin and synaptophysin and increased levels of doublecortin-positive cells in the dentate gyrus. These data extend GM-CSF pleiotropic neuroprotection mechanisms in AD and include regulatory T cell-mediated immunomodulation of microglial function, Aβ clearance, maintenance of synaptic integrity, and induction of neurogenesis. Together these data support further development of GM-CSF as a neuroprotective agent for AD.

Microglial phenotypes in Parkinson's disease and animal models of the disease

Over the last decade the important concept has emerged that microglia, similar to other tissue macrophages, assume different phenotypes and serve several effector functions, generating the theory that activated microglia can be organized by their pro-inflammatory or anti-inflammatory and repairing functions. Importantly, microglia exist in a heterogenous population and their phenotypes are not permanently polarized into two categories; they exist along a continuum where they acquire different profiles based on their local environment. In Parkinson's disease (PD), neuroinflammation and microglia activation are considered neuropathological hallmarks, however their precise role in relation to disease progression is not clear, yet represent a critical challenge in the search of disease-modifying strategies. This review will critically address current knowledge on the activation states of microglia as well as microglial phenotypes found in PD and in animal models of PD, focusing on the expression of surface molecules as well as pro-inflammatory and anti-inflammatory cytokine production during the disease process. While human studies have reported an elevation of both pro- or anti-inflammatory markers in the serum and CSF of PD patients, animal models have provided insights on dynamic changes of microglia phenotypes in relation to disease progression especially prior to the development of motor deficits. We also review recent evidence of malfunction at multiple steps of NFκB signaling that may have a causal interrelationship with pathological microglia activation in animal models of PD. Finally, we discuss the immune-modifying strategies that have been explored regarding mechanisms of chronic microglial activation.

The Immune System in Cancer Pathogenesis: Potential Therapeutic Approaches

Interplay among immune activation and cancer pathogenesis provides the framework for a novel subspecialty known as immunooncology. In the rapidly evolving field of immunooncology, understanding the tumor-specific immune response enhances understanding of cancer resistance. This review highlights the fundamentals of incorporating precision medicine to discover new immune biomarkers and predictive signatures. Using a personalized approach may have a significant, positive impact on the use of oncolytics to better guide safer and more effective therapies.

Granulocyte-macrophage colony stimulating factor exerts protective and immunomodulatory effects in cortical trauma

Neurodegeneration after traumatic brain injury is facilitated by innate and adaptive immunity and can be harnessed to affect brain repair. In mice subjected to controlled cortical impact (CCI), we show that treatment with granulocyte macrophage colony stimulating factor (GM-CSF) affects regulatory T cell numbers in the cervical lymph nodes coincident with decreased lesion volumes and increased cortical tissue sparing. This paralleled increases in neurofilament and diminished reactive microglial staining. Transcriptomic analysis showed that GM-CSF induces robust immune neuroprotective responses seven days following CCI. Together, these results support the therapeutic potential of GM-CSF for TBI.

GM-CSF induces neuroprotective and anti-inflammatory responses in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine intoxicated mice

Innate and adaptive immune responses can speed nigrostriatal neurodegeneration in Parkinson's disease (PD). We posit that GM-CSF can attenuate such responses. In 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) intoxicated mice, GM-CSF given prior to MPTP protected nigral dopaminergic neurons coincident with altered microglial morphologies and regulatory T cell (Treg) induction. Adoptive transfer of GM-CSF-induced Treg to MPTP mice protected nigral neurons. Gene expression analyses revealed novel immune-based neuronal protection pathways linked to the upregulation of IL-27. The results provide evidence that GM-CSF modulation of immunity could be of clinical benefit for PD.

The role of GM-CSF in enhancing immunotherapy of cancer

Evaluation of: Kanerva A, Nokisalmi P, Diaconu I et al. Antiviral and anti-tumor T-cell immunity in patients treated with GM-CSF coding oncolytic adenovirus. Clin. Cancer Res. 19(10), 2734–2744 (2013). The field of oncolytic viral therapy has been reinvigorated recently with publication of clinical data from two leading vectors, one based on HSV and one on Vaccinia, both of which express GM-CSF. Part of the reason for the improved clinical results with these vectors appears to be the enhanced immunotherapeutic mechanism of tumor destruction mediated by GM-CSF expression itself. The article by Kanerva et al. extends this work to describe early clinical use of an oncolytic adenovirus expressing GM-CSF, although the data are too preliminary to describe significant therapeutic benefits of GM-CSF expression in this backbone. However, the description of enhanced antitumor immunity in those patients that developed greater antiviral immunity after treatment provides a potent demonstration of the immunotherapeutic potential of epitope spreading after treatment with oncolytic viral therapies.

Tendências da produção do conhecimento de enfermagem no controle de infecção em oncologia

Os clientes com câncer apresentam complicações significativas de morbi-mortalidade relacionadas à infecção. Esta revisão integrativa tem como objetivo analisar a produção científica da enfermagem acerca do controle de infecções nos clientes com câncer. A busca dos 37 artigos incluídos foi por meio eletrônico em bases de dados, no período de 2002 a 2009. Os dados foram analisados na perspectiva da Metodologia de Categorização Epistemológica para a Pesquisa na Enfermagem. Os resultados indicam que a produção é internacional, mais setorizada na área da oncologia clínica, com ênfase nos clientes como sujeitos das investigações, tendência exógena da origem da infecção e prevalência de artigos de revisão de literatura. Conclui-se que a produção do conhecimento no controle de infecção é prioridade no cenário nacional, as ações devem ser baseadas numa visão sistêmica, considerando a complexidade que envolve os profissionais na prestação do cuidado de enfermagem.

Mucositis: The impact, biology and therapeutic opportunities of oral mucositis

The history of mucositis is as old as radiation- and chemotherapy. Despite being regularly reported and documented as one of the worst side effects of cancer therapy, relatively little was appreciated about the complexities of mucositis' pathogenesis until relatively recently. More frustrating for patients and clinicians, no effective treatment existed. Fortunately, the situation is changing; ongoing research is leading to a comprehensive understanding of the biology of mucositis, which has resulted in the development of novel interventions. While the FDA's approval of palifermin in 2004 was limited to only a small percentage of the at-risk population, the fact that the first registered anti-OM agent derived its efficacy from its pleotropic activities was conceptually demonstrative of the therapeutic potential of drugs that selectively interfere with mucositis' pathogenesis. A number of eclectic molecules, all designed to interfere with pathways that lead to injury are in pre-clinical and clinical development.

Molecular cloning, expression in Escherichia coli and production of bioactive homogeneous recombinant human granulocyte and macrophage colony stimulating factor

Human granulocyte and macrophage colony stimulating factor (hGM-CSF) is a glycoprotein that activates and enhances the differentiation and survival of neutrophils, eosinophils and macrophages, which play a key role in the innate immune response. Here we describe the construction of the hGM-CSF encoding gene, cloning, expression in Escherichia coli, purification of recombinant hGM-CSF, N-terminal amino acid sequencing, and biological activity assay using TF-1 cells. The results presented show that the combination of experimental strategies employed to obtain recombinant hGM-CSF can yield biologically active protein, and may be useful to scaling-up production of biosimilar protein.

GM-CSF-induced CD11c+CD8a--dendritic cells facilitate Foxp3+ and IL-10+ regulatory T cell expansion resulting in suppression of autoimmune thyroiditis

GM-CSF plays an essential role in the differentiation of dendritic cells (DCs). Our studies have shown that GM-CSF treatment can induce semi-mature DCs and CD4+CD25+ regulatory T cells (Tregs) and suppress ongoing autoimmunity in mouse models. In this study, we examined the differences in the potential of GM-CSF to exert tolerogenic function on CD8a+ and CD8a- sub-populations of DCs in vivo. We show that GM-CSF modulates CD8a-, but not CD8a+ DCs in vivo, by inhibiting the surface expression of activation markers MHC II and CD80 and production of inflammatory cytokines such as IL-12 and IL-1beta. Self-antigen [mouse thyroglobulin (mTg)] presentation by GM-CSF-exposed CD8a- DCs to T cells from mTg-primed mice induced a profound increase in the frequency of forkhead box P3 (FoxP3)-expressing T cells compared with antigen presentation by GM-CSF-exposed CD8a+ DCs and control CD8a+ and CD8a- DCs. This tolerogenic property of GM-CD8a- DCs was abrogated when IL-12 was added. GM-CSF-exposed CD8a- DCs could also induce secretion of significantly higher amounts of IL-10 by T cells from mTg-primed mice. Importantly, adoptive transfer of CD8a- DCs from GM-CSF-treated SCID mice, but not untreated mice, into wild-type CBA/J mice prevented the development of experimental autoimmune thyroiditis (EAT) in the recipient animals upon immunization with mTg. Collectively, our results show that GM-CSF renders CD8a- DCs tolerogenic, and these DCs induce Foxp3+ and IL-10+ Tregs.

Family Caring Strategies in Neutropenia

Aggressive chemotherapy protocols result in neutropenia in approximately half of all patients receiving chemotherapy. Thus, neutropenia continues to be a significant and potentially life-threatening side effect of treatment, even with use of colony-stimulating factors. Families of patients with neutropenia often provide the primary healing environment because most chemotherapy protocols are managed on an outpatient basis. To learn about the family's experience of managing chemotherapy-induced neutropenia (CIN), a grounded-theory methodology was used to analyze data from seven families. The central theme revealed by these families was "turbulent waiting with intensified connections." This meant that when families had a sense of greater vulnerability in response to the waiting after diagnosis of CIN, they connected intensely with each other and healthcare providers. Families reported that connections with nurses became more significant when neutropenia interrupted chemotherapy. Families also developed family caring strategies to manage this period of waiting for the chemotherapy to resume. These strategies included family inquiry, family vigilance, and family balancing. Nurses need to be aware of approaches to support the family's ability to manage CIN. Interventions and approaches constructed from the perspective of a family-professional partnership will enhance the family cancer experience as well as ongoing family growth and function.

Dendritic cells: emerging roles in tumor immunotherapy

The purpose of this article is to examine the use of myeloid dendritic cells (DCs) as immunotherapy in the treatment of cancer. DCs can be stimulated either from circulating blood or bone marrow progenitor cells using cytokines, particularly granulocyte macrophage-colony-stimulating factor (GM-CSF) (e.g., sargramostim, Leukine). GM-CSF has been shown to promote maturation, mobilization, and antigen presentation of DCs in vivo or ex vivo as a therapeutic cancer vaccine. Once stimulated, DCs can present tumor antigen to naive T cells to initiate an immune response. In addition to myeloid-related DC stimulation, antitumor properties of GM-CSF include direct cytotoxicity, antiangiogenesis properties, and potential upregulation of antibody-dependent cellular cytotoxicity. Oncology nurses need to be knowledgeable regarding new therapies. Using knowledge gained through reading professional journals and self-education, nurses can inform patients of new therapies, which may increase patients' hope.

Heat-inducible amplifier vector for high-level expression of granulocyte-macrophage colony-stimulating factor

PURPOSE

In cytokine immunotherapy of cancer it is critical to deliver sufficiently high local cytokine concentrations in order to reach the therapeutic threshold needed for clinical efficacy. Simultaneously, for optimal clinical safety adverse effects caused by high systemic cytokine levels must be minimized. One of the most promising anti-cancer therapeutic cytokines, granulocyte-macrophage colony-stimulating factor (GM-CSF), has elicited anti-tumour immune responses in animal studies and clinical trials. However, the clinical efficacy has been limited, with local GM-CSF levels being therapeutically insufficient and systemic toxicity being a limiting factor.

METHODS

To address these problems we have developed a novel GM-CSF expression vector, pAD-HotAmp-GM-CSF, which can provide high levels of GM-CSF expression, and induction of cytokine expression to limited tissue areas. This expression system combines inducible and amplifying elements in a single multi-genic construct. The first transcriptional unit contains the inducible element, the heat shock protein 70B (HSP70B) promoter that regulates expression of the transcription-activating factor tat.

RESULTS

Upon the binding of tat to the second promoter, the HIV2 long terminal repeat amplifies downstream gene expression of the therapeutic cytokine GM-CSF. Moderate hyperthermia at 42 degrees C for 30 min induced GM-CSF expression in pAD-HotAmp-GM-CSF that was over 2.5- and 2.8-fold higher than levels reached with HSP70B promoter alone and the prototypical human cytomegalovirus promoter.

CONCLUSIONS

Thus, the inducible amplifier vector, pAD-HotAmp-GM-CSF, represents a novel system for regulated and enhanced GM-CSF expression, which enables both greater efficacy and safety in cytokine immunotherapy of cancer.

Modulation of protein aggregation by polyethylene glycol conjugation: GCSF as a case study

Polyethylene glycol (PEG) conjugation to proteins has emerged as an important technology to produce drug molecules with sustained duration in the body. However, the implications of PEG conjugation to protein aggregation have not been well understood. In this study, conducted under physiological pH and temperature, N-terminal attachment of a 20 kDa PEG moiety to GCSF had the ability to (1) prevent protein precipitation by rendering the aggregates soluble, and (2) slow the rate of aggregation relative to GCSF. Our data suggest that PEG-GCSF solubility was mediated by favorable solvation of water molecules around the PEG group. PEG-GCSF appeared to aggregate on the same pathway as that of GCSF, as evidenced by (a) almost identical secondary structural transitions accompanying aggregation, (b) almost identical covalent character in the aggregates, and (c) the ability of PEG-GCSF to rescue GCSF precipitation. To understand the role of PEG length, the aggregation properties of free GCSF were compared to 5kPEG-GCSF and 20kPEG-GCSF. It was observed that even 5kPEG-GCSF avoided precipitation by forming soluble aggregates, and the stability toward aggregation was vastly improved compared to GCSF, but only marginally less stable than the 20kPEG-GCSF. Biological activity measurements demonstrated that both 5kPEG-GCSF and 20kPEG-GCSF retained greater activity after incubation at physiological conditions than free GCSF, consistent with the stability measurements. The data is most compatible with a model where PEG conjugation preserves the mechanism underlying protein aggregation in GCSF, steric hindrance by PEG influences aggregation rate, while aqueous solubility is mediated by polar PEG groups on the aggregate surface.

The molecular immunology of mucositis: implications for evidence-based research in alternative and complementary palliative treatments

The terms 'mucositis' and 'stomatitis' are often used interchangeably. Mucositis, however, pertains to pharyngeal-esophago-gastrointestinal inflammation that manifests as red, burn-like sores or ulcerations throughout the mouth. Stomatitis is an inflammation of the oral tissues proper, which can present with or without sores, and is made worse by poor dental hygiene. Mucositis is observed in a variety of immunosuppressed patients, but is most often consequential to cancer therapy. It appears as early as the third day of intervention, and is usually established by Day 7 of treatment. Mucositis increases mortality and morbidity and contributes to rising health care costs. The precise immune components involved in the etiology of mucositis are unclear, but evidence-based research (EBR) data has shown that applications of granulocyte-macrophage-colony stimulating factor prevent the onset or the exacerbation of oropharyngeal mucositis. The molecular implications of this observation are discussed from the perspective of future developments of complementary and alternative treatments for this condition. It must be emphasized that this article is meant to be neither a review on mucositis and the various treatments for it, nor a discussion paper on its underlying molecular immunology. It is a statement of the implications of EBR for CAM-based interventions for mucositis. It explores and discusses the specific domain of molecular immunology in the context of mucositis and its direct implications for EBR research in CAM-based treatments for mucositis.

Leishmania donovani amastigote component-induced colony-stimulating factor production by macrophages: modulation by morphine

The neuroimmunomodulatory effects of opiates during microbial infections are now well known; however, not much is known during leishmaniasis. Here, we report the effects of morphine on purified approximately 12-kDa component of Leishmania donovani amastigote antigen (LDAA-12)-induced colony-stimulating factor (CSF) production by mouse peritoneal macrophages (PMs) in vitro. Low concentrations (1 x 10(-9) and 1 x 10(-11) M) of morphine significantly (P < 0.05) augmented the production of CSFs, whereas high concentrations (1 x 10(-3) and 1 x 10(-5) M) inhibited CSF production. Morphine exerted a similar concentration-dependent biphasic effect on the LDAA-12-induced elaboration of granulocyte (G)-macrophage (M)-CSF (GM-CSF) and M-CSF by PMs in their conditioned medium, as quantified by using enzyme-linked immunosorbent assay. Furthermore, selective agonists of mu-(DAGO) and delta-(DPDPE) opioid receptors also, respectively, augmented and inhibited the production of CSFs. Pretreatment of PMs with naloxone (1 x 10(-5) M) significantly (P < 0.05) blocked the augmenting effect of morphine. In contrast, at 1 x 10(-5) M, naloxone lacked any effect on the inhibitory effect of morphine; however, its 100-fold higher concentration partially blocked it. This study, apparently for the first time, demonstrates that morphine, via surface opioid receptors, biphasically modulates the LDAA-12-induced CSF production by PMs, in vitro. These results thus show the implications of opiate abuse on the outcome of therapeutic interventions in areas where both visceral leishmaniasis and drug abuse are rampant.

Antitumor immune responses mediated by adenoviral GDEPT using nitroreductase/CB1954 is enhanced by high-level coexpression of heat shock protein 70

Gene-directed enzyme prodrug therapy (GDEPT) is a promising approach to local management of cancer through targeted chemotherapy. Killing localized tumors by GDEPT in a manner that induces strong antitumor cellular immune responses might improve local management and allow benefit in disseminated cancer. Here we evaluated the combination of nitroreductase (NTR)/CB1954 GDEPT with high-level expression of heat shock protein 70 (HSP70, a stress protein that can shuttle cytosolic peptides into antigen-presenting cells) for induction of antitumor immunity using adenovirus gene delivery in an aggressive and nonimmunogenic BALB/c syngeneic 4T1 breast cancer model. The mechanism of cell death and spectrum of stress proteins induced are likely to be important determinants of the resulting immune responses. We showed that NTR/CB1954 treatment of 4T1 cells gave both apoptotic and nonapoptotic killing. In vivo killing of 4T1 cells expressing NTR gave weak antitumor immunity and very limited induction of stress proteins including HSP70. High-level coexpression of HSP70 during NTR/CB1954-mediated killing of 4T1 cells in vivo gave much greater protection from tumor challenge (67% long-term survivors compared to 17%) and induced 4T1-specific cytotoxic T-cell responses. The enhancement of antitumor responses resulting from HSP70 coexpression was similar to that conferred by coexpression of GM-CSF.

Protective effect of (+)-catechin against 5-fluorouracil-induced myelosuppression in mice

The object of this study was to investigate the efficacy of (+)-catechin, which was isolated from Actinidia arguta Planch (Actinidiaceae), as a bone marrow cell proliferation-promoting compound against the hematotoxicity of 5-fluorouracil (5-FU) in mice. Intraperitoneally injected (+)-catechin (1 and 10 mg/kg per day) accelerated the recovery of the number of white blood cells (WBC) and platelets (PLT) but did not affect the number of circulating red blood cells (RBC). (+)-Catechin also augmented the number of myelocytes and splenocytes. Dual color flow cytometric analysis revealed that (+)-catechin reversed the reduction of the population of leukocytes (CD11b+ monocytes, Gr-1+ granulocytes and CD3+ T and CD45RA+ B lymphocytes) in whole blood, spleen and bone marrow caused by 5-FU. (+)-Catechin (1 and 10 mg/kg per day) showed remarkable recovery of Gr-1+ cells in all three types of tissues and of CD11b+ cells in the bone marrow cells. These findings suggest that (+)-catechin selectively enhances the recovery of the population of granulocytes reduced by 5-FU in mice.

Bioimmunotherapy of rodent malaria: co-treatment with recombinant mouse granulocyte-macrophage colony-stimulating factor and an enkephalin fragment peptide Tyr-Gly-Gly

We have earlier shown that recombinant mouse granulocyte-macrophage colony-stimulating factor (rmGM-CSF) and methionine-enkephalin co-treatment can protect mice from malaria. We now report the bioimmunotherapeutic effect of rmGM-CSF and a synthetic enkephalin fragment peptide Tyr-Gly-Gly (TGG) co-treatment on blood-induced Plasmodium berghei infection in Swiss mice. Mice were completely aparasitimic following co-treatment with rmGM-CSF (10.0 microg/kg) and TGG (2.0 mg/kg x 3 per day, intraperitoneally (i.p.)) starting from day -1 to day +4; however, in monotherapy, neither of these agents showed any detectable bioimmunotherapeutic effect. Curiously, similar co-treatment with rmGM-CSF (10.0 microg/kg) and higher doses of TGG (10.0 mg/kg) did not protect the mice. The combined bioimmunotherapeutic effect of these agents was abrogated by the separate administration each of rabbit neutralizing anti-rmGM-CSF antibody, non-selective opioid receptor antagonist naltrexone (10.0 mg/kg x 6 per day, i.p.), and silica (3.0 mg per mouse, intravenously (i.v.)). The peritoneal and splenic macrophages from the protected mice showed a significant (P<0.05) increase in their pool-size and the phagocytic activity, ex vivo. Furthermore, the protected mice, as compared to the unprotected ones, showed a significant (P<0.05) maximum increase in their serum nitrate and nitrite, interferon-gamma (IFN-gamma), and tumor necrosis factor-alpha (TNF-alpha) levels in their splenic homogenates, on the day before the beginning of the resolution of parasitaemia. Selective inhibitors of both inducible (aminoguanidine) and all forms (L-N(G)-monomethyl arginine) of nitric oxide (NO) synthase, significantly (P<0.05) augmented the mortality of co-treated mice, suggesting the role of NO in protection. These data show that, in P. berghei-infected mice, co-treatment with rmGM-CSF and conditional doses of TGG can impart protection, apparently through partly NO-dependent and macrophage-mediated mechanism(s).

Evidence-based care for the neutropenic patient with leukemia

OBJECTIVES

To provide an overview of risk factors for increased severity of infection, and a summary of neutropenic care guidelines based on the scientific literature.

DATA SOURCES

Research studies, review articles, book chapters.

CONCLUSION

Neutropenia is one of the most common and clinically significant toxicities of therapy for patients with leukemia. The risk of infection is extremely high and is associated with significant morbidity and mortality. Specific risk factors for serious or life-threatening infection must be identified in this patient population and abrogated when possible.

IMPLICATIONS FOR NURSING PRACTICE

Implementation of evidence-based preventive and management strategies for patients with neutropenia can optimize patient outcomes. Internalization of these concepts into the nursing care we provide to patients with leukemia exemplifies best practice.

Cytokines as clinical adjuvants: how far are we?

In spite of the explosive growth in the discovery of cytokines and chemokines and in the understanding of their modes of action, clinical use of such agents as adjuvants has been primarily restricted to patients with cancer or chronic viral infections suffering from various levels of immune impairment and for whom the chemotherapeutic armamentarium, as well as other forms of immunotherapy, have been exhausted. This cautious approach has been justified by the difficulties inherent to the biological function and delivery of such pleiotropic agents, where doses needed to achieve the targeted immune enhancement often result in serious side effects, especially during systemic administration. In addition, optimization of dosages, administration schedules and biological effects in humans often do not correlate well with preclinical data derived from animal models. Nevertheless, novel preventive immunization strategies that target a precise type of immune response in immunocompetent individuals are expected to greatly benefit from the incorporation of cytokines and chemokines. This review provides an overview of current clinical administration of cytokines as well as a description of select Phase I testing of new agents designed to enhance immune defenses in vivo.

Epoetin alfa: current and future indications and nursing implications

Cancer-related anemia commonly is associated with fatigue and decreased quality of life (QOL). Treatment to achieve optimal hemoglobin levels in patients receiving chemotherapy can alleviate common symptoms of anemia and may allow patients to have more meaningful survival time while on chemotherapy. New studies have suggested that epoetin alfa (Procrit, Ortho Biotech Products, LP, Raritan, NJ) can be administered safely and effectively once a week in patients with anemia other than those patients with cancer receiving concomitant chemotherapy. Preclinical studies and pilot clinical studies also have suggested a new application for epoetin alfa in improving cognitive function. Oncology nurses skilled at anticipating, assessing, and managing anemia and its symptoms can be instrumental in improving the QOL of patients with cancer. They should be aware of clinical trials that have suggested advantages of improved dosing schedules and new applications for epoetin alfa.