Influence of tumor cell culture supernatants on macrophage functional polarization: in vitro models of macrophage-tumor environment interaction.

AIMS AND BACKGROUND: Macrophages are heterogeneous cells with extensive functional plasticity; they can change their functional profiles repeatedly in response to environmental changes anywhere between their extreme phenotypical programs (labeled as M1 and M2 polarization, respectively). In terms of antitumoral immune response, M1 macrophages are considered to be beneficial, while M2 macrophages supposedly promote tumor progression. Tumor-associated macrophages (TAMs) represent a major leukocyte population present in many tumors. Although many studies indicate that TAMs elicit several M2-associated protumoral functions, including promotion of angiogenesis, matrix remodeling and suppression of adaptive immunity, their role regarding tumor progression is still controversial. The aim of the present study was to develop an appropriate in vitro model to study the effect of tumor-secreted soluble factors on the functional phenotype of macrophages. METHODS AND STUDY DESIGN: THP-1 human monocytic line cells and peripheral blood mononuclear cells from healthy volunteers were used for macrophage differentiation; primary tumor cell culture supernatants or tumor cell line supernatants were employed along with various cytokines, growth factors and other stimuli to design different model variants and to better mimic the in vivo tumor microenvironment. RESULTS: The cytokine secretion patterns of these macrophages suggest that primary tumor cell culture supernatants are able to switch the macrophage phenotype or to induce functional polarization of macrophages toward a mixed M1/M2 phenotype. Conclusions. These data support the hypothesis that TAM behavior is modulated by the tumor microenvironment itself.

Bacterial extract cantastim activates macrophages via TLR-2.

CANTASTIM is a second generation bacterial immunomodulator. The aim of this study was to examine the mechanism by which bacterial immunomodulator CANTASTIM induces production of inflammatory cytokines in monocytes/macrophages. Proinflammatory cytokines were induced in PMA-differentiated THP-1 cells by stimulation with TLR agonists and CANTASTIM in the presence or absence of anti-TLR blocking antibodies or isotype matched control antibodies. Also, RNA interference was used to knockdown TLR2 or TLR4 expression in PMA-differentiated THP-1 cells before stimulation. As expected, induction of TNF-alpha and IL-6 by TLR4 agonist LPS was inhibited in a significant manner by anti-TLR4 but not by anti-TLR2 antibody. Unexpectedly, treatment with anti-LR2 blocking antibody inhibited only IL-6 production induced by Pam3CSK4 while the level of TNF-alpha was unchanged. When cells were stimulated by TLR2 agonist heat-killed Listeria monocytogenes the release of TNF-alpha was significantly attenuated by anti-TLR2 antibodies. Silencing of TLR2 led to a statistically significant inhibition of TNF-alpha secretion induced by TLR2 agonist while siRNA silencing of TLR4 did not affect the response to TLR2 agonist. Cells exposed to CANTASTIM produced significant levels of pro-inflammatory cytokines but the levels were lower than LPS-stimulated cells. Production of both cytokines was inhibited by treatment with anti-TLR2 blocking antibody and not by anti-TLR4 antibody. Silencing of TLR2 led to a statistically significant inhibition of TNF-a secretion induced by CANTASTIM while silencing of TLR4 had no effect on the response to CANTASTIM. These results support the hypothesis that CANTASTIM may exert its immunomodulatory and adjuvant activities through interaction of its bacterial components with TLR2.

Serum perioperative profile of cytokines in patients with squamous cell carcinoma of the larynx.

OBJECTIVE: Altered immune, inflammatory, and angiogenesis responses have been noticed in head and neck cancer, and many of these responses have been associated with a poor clinical outcome. The objective of this study was to evaluate several immune mediators in the sera of patients with squamous cell carcinoma (SCC) of the larynx undergoing curative surgery in connection with clinicopathologic factors. METHODS: Multiplex analysis of cytokines (interleukin [IL]-6, IL-8, IL-10, tumour necrosis factor α [TNF-α], interferon-γ [IFN-γ]), chemokines (monocyte chemoattractant protein 1 [MCP-1], macrophage inflammatory protein 1α [MIP-1α], and epithelial neutrophil-activating protein 78 [ENA-78]), and growth factors (vascular endothelial growth factor and basic fibroblast growth factor) in the serum of patients with laryngeal cancer and healthy controls was performed using xMap technology. RESULTS: Patients with SCC presented an altered cytokine profile compared to healthy controls, both preoperatively (higher levels of IL-8 and IL-10) and postoperatively (higher values for IL-6, IL-8, IL-10, and TNF-α). Heavy smoking was associated with significantly lower levels of ENA-78 and higher levels of IL-8. CONCLUSION: Differences noticed in patients' immune mediator profiles seem to be attributable to both disease and treatment. Further longitudinal studies are necessary to elucidate the involvement of immune mediators in disease progression and clinical evolution.

Serum levels of adipokines resistin and leptin in patients with colon cancer.

Adipose tissue displays characteristics of an endocrine organ releasing a number of adipocyte-specific factors known as adipocytokines. It has been recently suggested that adipocytokines may play a role in pathogenesis and progression of certain cancers, in particular in colorectal cancer. The aim of this study was to investigate the association between several blood adipocytokine levels and clinicopathological characteristics of colon cancer patients undergoing surgery. The study group comprised of 29 patients who underwent surgical resection for colon cancer at Emergency University Hospital Bucharest and 27 healthy volunteers. The serum levels of adipocytokines were measured using multianalyte xMap profiling technology (Luminex). Resistin levels were significantly higher in colon cancer patients while leptin serum levels were significantly lower as compared to controls. Leptin levels decreased gradually with tumor stage and aggressiveness. Taken together, these results of this study suggest that adipokines, in particular resistin and leptin may be involved in development and progression of colon cancer.

[Involvement of soluble mediators of inflammation in the pathogenic agent interaction--immune system in acute bacterial meningitis]. / Implicarea mediatorilor solubili ai inflamatiei în interactia agent patogen--sistem imun din cadrul meningitelor infectioase.

Acute Bacterial Meningitis is a medical emergency, which warrants early diagnosis and aggressive therapy, which in most cases must be initiated as an "empirical" treatment. Such an approach needs permanent epidemiological surveillance due to the major variability of the etiological agents depending upon time, geographical areas and demographic characteristics of the population. A program for the surveillance of meningitis is in progress in Romania, but the available clinical inbformation is incomplete and not well documented by paraclinical data, poorly reflecting the real incidence of the disease. The specific anatomic localization of the disease has major influences on the antiinfectious immune response. Inflammation is involved in the disease pathogenesis, especially in promotion and evolution of neurological sequelae (neuronal demyelinisation and degeneration) even in case of pathogen clearance following antimicrobial therapy. Activation of the immune response in a immunologically "privileged "region can lead to the break of tolerance and induction of autoimmunity (neuronal degenerescence). On the other hand, an efficient immune response is necessary for the clearance of pathogenic agents. A detailed investigation of the interaction between pathogenic agents and the immune system in relation to the particular meningeal localization and also a study on the involvement of soluble mediators of inflammation (cytokines, chemokines) in the pathogenesis of meningitis might prove useful for differential diagnosis (viral or "aseptic" meningitis) and also for elucidating the mechanisms which that underlie the disease pathogenesis/neurological complications.