Expression Of Immune Mediators Research Articles

The immune plasticity of mesenchymal stromal cells from mice and men concordances and discrepancies

During the last decade, mesenchymal stromal cells (MSCs) have generated numbers of clinical trials to address inflammatory diseases such as GVHD, Crohn’s disease and lupus. Animal models and therapeutic protocols in patients have demonstrated their anti-inflammatory and immunosuppressive properties towards adaptive immune cells. However, the basis of their immune suppression remains hotly debated. In the present review, we discuss the comparative isolation of human and rodent MSCs, their respective immune properties, whether constitutive or licensed by inflammatory or immune reactions, as well as differential efficacy as observed in GVHD clinical trials and related mouse models. Rodent MSCs display a number of immune differences with human MSCs regarding to ease of isolation, licensing pathways resulting in immunosuppression, and expression of immune mediators. These observations urge for caution when translating results generated in murine models into clinical settings.

P1-01-14: Gene Expression of Immune Mediators within Nipple Aspirate Fluid and Ductal Lavage from Normal and Cancerous Breasts.

Abstract The majority of breast cancers are thought to initiate in the lining of the 6 to 8 ducts that exit the nipple. Evidence suggests that the presence of nipple aspirate fluid (NAF), and in particular NAF containing atypical epithelial cells, in the ducts is predictive of future breast cancer risk. Although NAF fluid and cells may be representative of a preneoplastic state, use of NAF has not proven to represent a robust indicator for future malignancy. Chronic infiltration of tissues by immune cells predisposes them to future malignancy. Since macrophages can represent up to half of the total cells recovered from NAF, and their presence within malignant breast tumors has predictive value in terms of survival, we hypothesized that changes in the inflammatory microenvironment of breast ducts may foster future malignancy and/or provide an early indicator of future neoplasia. To test this hypothesis, we conducted an exploratory study to investigate gene expression in NAF and ductal lavage fluid. We first used real-time PCR to quantitatively measure mRNA expression of select genes within the cellular milieu of NAF to determine if that microenvironment correlated with a tumor-promoting state. Expression of multiple genes was observed in 15 samples collected from healthy volunteers, with robust expression of myeloid-associated genes including CD14, CD68, CCL3, CSF1 and IL1B observed in the majority of samples. To determine whether similar inflammatory microenvironments were found within each duct, and whether they were comparable to those in NAF-containing ducts, ductal lavage (DL) samples were obtained from 4 different ducts at the same time as NAF collection. Out of 7 volunteers, 4 provided samples allowing comparison between NAF and DL, and between multiple ducts. Analysis of gene expression from these healthy volunteers indicated that gene expression differed between NAF samples and each DL sample. More importantly, unique gene expression was found for each duct sampled, indicating that the immune microenvironment within each duct is distinct from other ducts within the same breast. In order to identify a potential inflammatory gene signature, we then obtained NAF samples from patients with breast cancer that had not received neoadjuvant chemotherapy prior to surgery, from both the cancerous and contralateral breasts. With 4 patients analyzed, no consistent expression difference has thus far been observed, indicating either that the relevant genes have not been identified, or that analysis of inflammatory genes within NAF may not be a predictive method with which to evaluate risk of future malignancy in women that produce NAF. A larger study is warranted to further investigate the significance of inflammatory gene expression in breast ductal fluid. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-01-14.

The WxxxE effector EspT triggers expression of immune mediators in an Erk/JNK and NF-κB-dependent manner

Enteropathogenic Escherichia coli (EPEC), enterohaemorrhagic E. coli (EHEC) and Citrobacter rodentium colonize their respective hosts while forming attaching and effacing lesions. Their infection strategy relies on translocation of a battery of type III secretion system effectors, including Map, EspM and EspT, which belong to the WxxxE/SopE family of guanine nucleotide exchange factors. Using the C. rodentium mouse model we found that EspT triggers expression of KC and TNFα in vivo. Indeed, a growing body of evidence suggests that, in addition to subversion of actin dynamics, the SopE and the WxxxE effectors activate signalling pathways involved in immune responses. In this study we found that EspT induces expression of the pro-inflammatory mediators cyclooxygenase-2 (COX-2) an enzyme involved in production of prostaglandin E(2) (PGE2), interleukin (Il)-8 and Il-1β in U937 human macrophages by activating the nuclear factor kappa-B (NF-κB), the extracellular signal-regulated kinases 1 and 2 (Erk1/2) and c-Jun N-terminal kinase (JNK) pathways. Since EspT modulates the activation of Cdc42 and Rac1, which mediates bacterial invasion into epithelial cells, we investigated the involvement of these Rho GTPases and bacterial invasion on pro-inflammatory responses and found that (i) Rac1, but not Cdc42, is involved in EspT-induced Il-8 and Il-1β secretion and (ii) cytochalasin D inhibits EspT-induced EPEC invasion into U937 but not Il-8 or Il-1β secretion. These results suggest that while EPEC translocates a number of effectors (i.e. NleC, NleD, NleE, NleH) that inhibit inflammation, a subset of strains, which encode EspT, employ an infection strategy that also involves upregulation of immune mediators.

Pseudomonas aeruginosa autoinducer modulates host cell responses through calcium signalling

The opportunistic pathogen Pseudomonas aeruginosa utilizes a cell density-dependent signalling phenomenon known as quorum sensing (QS) to regulate several virulence factors needed for infection. Acylated homoserine lactones, or autoinducers, are the primary signal molecules that mediate QS in P. aeruginosa. The autoinducer N-3O-dodecanoyl-homoserine lactone (3O-C12) exerts effects on mammalian cells, including upregulation of pro-inflammatory mediators and induction of apoptosis. However, the mechanism(s) by which 3O-C12 affects mammalian cell responses is unknown. Here we report that 3O-C12 induces apoptosis and modulates the expression of immune mediators in murine fibroblasts and human vascular endothelial cells (HUVEC). The effects of 3O-C12 were accompanied by increases in cytosolic calcium levels that were mobilized from intracellular stores in the endoplasmic reticulum (ER). Calcium release was blocked by an inhibitor of phospholipase C, suggesting that release occurred through inositol triphosphate (IP3) receptors in the ER. Apoptosis, but not immunodulatory gene activation, was blocked when 3O-C12-exposed cells were co-incubated with inhibitors of calcium signalling. This study indicates that 3O-C12 can activate at least two independent signal transduction pathways in mammalian cells, one that involves increases in intracellular calcium levels and leads to apoptosis, and a second pathway that results in modulation of the inflammatory response.

Intragraft gene and protein expression in rat liver allografts treated with costimulatory blockade alone or in combination with CyA

Background. Costimulatory blockade has been shown to prevent acute rejection (AR) and promote long-term graft survival in a number of animal models including nonhuman primates. The effect of concomitant administration of conventional immunosuppressives on long-term liver allograft survival and intragraft expression of immune mediators has not previously been examined. Materials and methods. A high-responding Dark Agouti to Lewis orthotopic liver transplant (LEW OLT) model was used to compare anti-CD154 alone, or in combination with cyclosporin (CyA) on allograft survival. Donor-specific reactivity was assessed by mixed lymphocyte reaction (MLR) and allogeneic skin grafts. Surviving rats were euthanized on day 150 and intragraft gene (CD80, 86, 152, 154, IFN-γ, IL-2, IL-6, IL-10, IL-13, TNF-α, TGF-β, IL-7, Fas-ligand, Granzyme B, bax, and bcl 2) and protein (CD4, CD8, ED1, CD154, CD80, CD86) expression was measured. Results. Untreated control recipients had a median survival time of 5 days. Recipients treated with anti-CD154 survived to beyond 150 days with no evidence of AR. Concomitant administration of CyA did not alter the long-term survival. There was no difference in the serum aspartate aminotransferase between treatment groups or a change over time. All treated recipients showed a reduction in donor-specific MLR at day 40 and 60 but had persistence of donor reactivity to skin grafts at day 100. Histologically, liver architecture was well preserved despite the presence of a nondestructive mononuclear cell infiltrate. Analysis of intragraft gene expression revealed an inverse relationship between the duration of anti-CD154 therapy and the gene expression of costimulatory molecules and Th1 cytokine transcripts. The pro-apoptotic gene, bax, was increased in recipients treated with anti-CD154, but not CyA, compared with normal liver. Conclusions. These data demonstrate that anti-CD154 therapy either alone or in combination with CyA allows for the long-term survival of liver allografts in the rat despite there being a difference in the intragraft gene and protein profile.

Adoptive CD8+ T-cell immunotherapy of AIDS patients with Kaposi's sarcoma.

This article reviews published and original findings from two clinical trials of adoptive CD8+ T-cell immunotherapy of patients with acquired immunodeficiency syndrome (AIDS) and Kaposi's sarcoma (KS). In the first trial, AIDS patients with either KS or oral hairy leukoplakia (OHL) received five rounds of reinfusions of 10(8)-10(10) ex vivo expanded and activated autologous CD8+ T cells. Recombinant interleukin-2 (rIL-2) was coadministered only with the fifth and final infusion. Improvement, and in some cases, resolution of OHL, KS, and candidiasis was observed with no side effects. The observation that clinical improvement of KS was more pronounced when reinfusion of CD8+ T cells was followed by rIL-2 infusion led to a second clinical trial designed to examine the effect of repeated infusions of autologous CD8+ T cells with concomitant rIL-2 administration in the treatment of AIDS-related KS. Improvement of KS status was observed in four out of the eight patients studied (three partial and one complete response). The CD8+ T-cell immunotherapy protocol also provided the opportunity to comparatively study CD8+ T-cell-associated genetic programs. Baseline expression patterns of soluble and surface immune markers by CD8+ T cells from AIDS patients and uninfected controls were predominantly of the type 1 type and differed mainly at a quantitative or kinetic level. Deficiencies in immune mediator expression by CD8+ T cells from AIDS patients tended to dissipate with progression through the protocol. Findings are discussed in the context of current knowledge and therapeutic implications of CD8+ T-cell function in AIDS and neoplasia.

Dysregulated Expression of Soluble Immune Mediator Receptors in a Subset of Patients with Chronic Fatigue Syndrome:

Individuals with chronic fatigue syndrome (CFS) have significantly increased proportions of activated CD8+T cells, decreased natural killer (NK) cell cytotoxic and lymphoproliferative activities, elevated serum levels of tumor necrosis factor (TNF)-α and detectable TNF-β, interleukin (IL)-lβ, and IL-6 mRNA in peripheral blood mononuclear cells (PBMC). We report here that CFS patients as a group also have significantly higher levels, as compared to controls, of soluble TNF receptor type I (sTNF-RI or sCDl20a), sIL-6R (sCD126) and β2-microglobulin (β2-m), but not of IL-1 receptor antagonist (IL-1Ra). Correlative and population distribution studies that included lymphoid phenotypic distributions and function as well as soluble immune mediator expression levels revealed the existence of at least two mainly nonoverlapping immunological categories among CFS patients with either: (1) dysregulaled TNF-α/β expression in association with changes in the serum levels of IL-lα, IL-4, sIL-2R and IL-lRa, PBMC-associated...

Dysregulated Expression of Tumor Necrosis Factor in Chronic Fatigue Syndrome: Interrelations with Cellular Sources and Patterns of Soluble Immune Mediator Expression

Among a group of 70 individuals who met the criteria established by the Centers for Disease Control and Prevention (Atlanta) for chronic fatigue syndrome (CFS), 12%-28% had serum levels exceeding 95% of control values for tumor necrosis factor (TNF) alpha, TNF-beta, interleukin (IL) 1 alpha, IL-2, soluble IL-2 receptor (sIL-2R), or neopterin; overall, 60% of patients had elevated levels of one or more of the nine soluble immune mediators tested. Nevertheless, only the distributions for circulating levels of TNF-alpha and TNF-beta differed significantly in the two populations. In patients with CFS--but not in controls--serum levels of TNF-alpha, IL-1 alpha, IL-4, and sIL-2R correlated significantly with one another and (in the 10 cases analyzed) with relative amounts (as compared to beta-globin or beta-actin) of the only mRNAs detectable by reverse transcriptase-coupled polymerase chain reaction in peripheral-blood mononuclear cells: TNF-beta, unspliced and spliced; IL-1 beta, lymphocyte fraction; and IL-6 (in order of appearance). These findings point to polycellular activation and may be relevant to the etiology and nosology of CFS.