CCR4+ CD8+ T cells clonally expand to differentiated effectors in murine psoriasis and in human psoriatic arthritis.

Psoriasis is a chronic inflammatory skin disease with an autoimmune component and associated with joint inflammation in up to 30% of cases. To investigate autoreactive T cells, we developed an imiquimod-induced psoriasis-like inflammation model in K5-mOVA.tg C57BL/6 mice expressing ovalbumin (OVA) on the keratinocyte membrane, adoptively transferred with OT-I OVA-specific CD8+ T cells. We evaluated the expansion of OT-I CD8+ T cells and their localization in skin, blood, and spleen. scRNA-seq and TCR sequencing data from patients with psoriatic arthritis were also analyzed. In the imiquimod-treated K5-mOVA.tg mouse model, OT-I T cells were markedly expanded in the skin and blood at early time points. OT-I T cells in the skin showed mainly CXCR3+ effector memory phenotype, whereas in peripheral blood there was an expansion of CCR4+ CXCR3+ OT-I cells. At a later time point, expanded OVA-specific T-cell population was found in the spleen. In patients with psoriatic arthritis, scRNA-seq and TCR sequencing data showed clonal expansion of CCR4+ TCM cells in the circulation and further expansion in the synovial fluid. Importantly, there was a clonotype overlap between CCR4+ TCM in the peripheral blood and CD8+ T-cell effectors in the synovial fluid. This mechanism could play a role in the generation and spreading of autoreactive T cells to the synovioentheseal tissues in psoriasis patients at risk of developing psoriatic arthritis.

From the Skin to Distant Sites: T Cells in Psoriatic Disease.

Human skin has long been known as a protective organ, acting as a mechanical barrier towards the external environment. More recent is the acquisition that in addition to this fundamental role, the complex architecture of the skin hosts a variety of immune and non-immune cells playing preeminent roles in immunological processes aimed at blocking infections, tumor progression and migration, and elimination of xenobiotics. On the other hand, dysregulated or excessive immunological response into the skin leads to autoimmune reactions culminating in a variety of skin pathological manifestations. Among them is psoriasis, a multifactorial, immune-mediated disease with a strong genetic basis. Psoriasis affects 2-3% of the population; it is associated with cardiovascular comorbidities, and in up to 30% of the cases, with psoriatic arthritis. The pathogenesis of psoriasis is due to the complex interplay between the genetic background of the patient, environmental factors, and both innate and adaptive responses. Moreover, an autoimmune component and the comprehension of the mechanisms linking chronic skin inflammation with systemic and joint manifestations in psoriatic patients is still a major challenge. The understanding of these mechanisms may offer a valuable chance to find targetable molecules to treat the disease and prevent its progression to severe systemic conditions.

Purinergic Signaling and Inflammasome Activation in Psoriasis Pathogenesis.

Psoriasis is a chronic inflammatory disease of the skin associated with systemic and joint manifestations and accompanied by comorbidities, such as metabolic syndrome and increased risk of cardiovascular disease. Psoriasis has a strong genetic basis, but exacerbation requires additional signals that are still largely unknown. The clinical manifestations involve the interplay between dendritic and T cells in the dermis to generate a self-sustaining inflammatory loop around the TNFα/IL-23/IL-17 axis that forms the psoriatic plaque. In addition, in recent years, a critical role of keratinocytes in establishing the interplay that leads to psoriatic plaques' formation has re-emerged. In this review, we analyze the most recent evidence of the role of keratinocytes and danger associates molecular patterns, such as extracellular ATP in the generation of psoriatic skin lesions. Particular attention will be given to purinergic signaling in inflammasome activation and in the initiation of psoriasis. In this phase, keratinocytes' inflammasome may trigger early inflammatory pathways involving IL-1ß production, to elicit the subsequent cascade of events that leads to dendritic and T cell activation. Since psoriasis is likely triggered by skin-damaging events and trauma, we can envisage that intracellular ATP, released by damaged cells, may play a role in triggering the inflammatory response underlying the pathogenesis of the disease by activating the inflammasome. Therefore, purinergic signaling in the skin could represent a new and early step of psoriasis; thus, opening the possibility to target single molecular actors of the purinome to develop new psoriasis treatments.

The network of non-coding RNAs and their molecular targets in breast cancer.

BACKGROUND: Non-coding RNAs are now recognized as fundamental components of the cellular processes. Non-coding RNAs are composed of different classes, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). Their detailed roles in breast cancer are still under scrutiny. MAIN BODY: We systematically reviewed from recent literature the many functional and physical interactions of non-coding RNAs in breast cancer. We used a data driven approach to establish the network of direct, and indirect, interactions. Human curation was essential to de-convolute and critically assess the experimental approaches in the reviewed articles. To enrol the scientific papers in our article cohort, due to the short time span (shorter than 5 years) we considered the journal impact factor rather than the citation number. The outcome of our work is the formal establishment of different sub-networks composed by non-coding RNAs and coding genes with validated relations in human breast cancer. This review describes in a concise and unbiased fashion the core of our current knowledge on the role of lncRNAs, miRNAs and other non-coding RNAs in breast cancer. CONCLUSIONS: A number of coding/non-coding gene interactions have been investigated in breast cancer during recent years and their full extent is still being established. Here, we have unveiled some of the most important networks embracing those interactions, and described their involvement in cancer development and in its malignant progression.

T Cell Subpopulations in the Physiopathology of Fibromyalgia: Evidence and Perspectives.

Fibromyalgia is one of the most important "rheumatic" disorders, after osteoarthritis. The etiology of the disease is still not clear. At the moment, the most defined pathological mechanism is the alteration of central pain pathways, and emotional conditions can trigger or worsen symptoms. Increasing evidence supports the role of mast cells in maintaining pain conditions such as musculoskeletal pain and central sensitization. Importantly, mast cells can mediate microglia activation through the production of proinflammatory cytokines such as IL-1ß, IL-6, and TNFα. In addition, levels of chemokines and proinflammatory cytokines are enhanced in serum and could contribute to inflammation at systemic level. Despite the well-characterized relationship between the nervous system and inflammation, the mechanism that links the different pathological features of fibromyalgia, including stress-related manifestations, central sensitization, and dysregulation of the innate and adaptive immune responses is largely unknown. This review aims to provide an overview of the current understanding of the role of adaptive immune cells, in particular T cells, in the physiopathology of fibromyalgia. It also aims at linking the latest advances emerging from basic science to envisage new perspectives to explain the role of T cells in interconnecting the psychological, neurological, and inflammatory symptoms of fibromyalgia.

A Peptide Nucleic Acid (PNA) Masking the miR-145-5p Binding Site of the 3'UTR of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) mRNA Enhances CFTR Expression in Calu-3 Cells.

Peptide nucleic acids (PNAs) have been demonstrated to be very useful tools for gene regulation at different levels and with different mechanisms of action. In the last few years the use of PNAs for targeting microRNAs (anti-miRNA PNAs) has provided impressive advancements. In particular, targeting of microRNAs involved in the repression of the expression of the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which is defective in cystic fibrosis (CF), is a key step in the development of new types of treatment protocols. In addition to the anti-miRNA therapeutic strategy, inhibition of miRNA functions can be reached by masking the miRNA binding sites present within the 3'UTR region of the target mRNAs. The objective of this study was to design a PNA masking the binding site of the microRNA miR-145-5p present within the 3'UTR of the CFTR mRNA and to determine its activity in inhibiting miR-145-5p function, with particular focus on the expression of both CFTR mRNA and CFTR protein in Calu-3 cells. The results obtained support the concept that the PNA masking the miR-145-5p binding site of the CFTR mRNA is able to interfere with miR-145-5p biological functions, leading to both an increase of CFTR mRNA and CFTR protein content.

Blood to skin recirculation of CD4+ memory T cells associates with cutaneous and systemic manifestations of psoriatic disease.

Blood to skin recirculation could play a role in the pathogenesis of psoriasis. To investigate this possibility we dissected the phenotype of circulating T cells in psoriasis patients, calculated the correlation the clinical parameters of the disease and performed a parallel bioinformatics analysis of gene expression data in psoriatic skin. We found that circulating CCR6+ CD4+ TEM and TEFF cells significantly correlated with systemic inflammation. Conversely, the percentage of CXCR3+ CD4+ TEM cells negatively correlated with the severity of the cutaneous disease. Importantly CLA+ CD4+ TCM cells expressing CCR6+ or CCR4+CXCR3+ negatively correlated with psoriasis severity suggesting recruitment to the skin compartment. This assumption was reinforced by gene expression data showing marked increase of CCR7 and CLA-encoding gene SELPLG expression in psoriatic skin and strong association of their expression. The data enlightens a role for CD4+ T cells trafficking between blood and skin in cutaneous and systemic manifestations of psoriasis.

A role for CCR5(+)CD4 T cells in cutaneous psoriasis and for CD103(+) CCR4(+) CD8 Teff cells in the associated systemic inflammation.

Recent results have identified critical components of the T cell response involved in the initiation and amplification phases of psoriasis. However the link between T cell responses arising in the skin and the systemic inflammation associated with severe psoriasis is largely unknown. We hypothesized that specific subsets of memory T cells recirculating from the skin could play a role. We therefore dissected the circulating memory T cell compartment in patients by analyzing the TCM, TEM and Teff phenotype, the pattern of CCR4 and CCR5 chemokine receptor expression and the expression of the tissue homing molecule CD103. For each subset we calculated the correlation with the Psoriasis Area and Severity Index (PASI) and with the extent of systemic inflammation measured as serum level of the prototypic short pentraxin, C reactive protein (CRP). Validation was performed by comparison with gene expression data in psoriatic plaques. We found that circulating CD103(+)CCR4(+)CCR5(+) and CCR4(+)CCR6(-) CD8(+) Teff cells, were highly correlated with CRP levels as well as with the validated index PASI, reflecting a link between skin involvement and systemic inflammation in patients with severe psoriasis. In addition we observed a contraction of circulating CCR5(+) T cells in psoriasis patients, with a highly significant inverse correlation between CCR5(+)CD4 T cells and the PASI score. Increased expression of CCR5 and CCL5 genes in psoriatic skin lesions was consistent with an accumulation of CCR5(+) cells in psoriatic plaques indicating a role for CCR5/CCL5 axis in disease pathogenesis.

Inhibition of CCR7/CCL19 axis in lesional skin is a critical event for clinical remission induced by TNF blockade in patients with psoriasis.

Despite the evidence that tumor necrosis factor (TNF) inhibitors block TNF and the downstream inflammatory cascade, their primary mechanism of action in inhibiting the self-sustaining pathogenic cycle in psoriasis is not completely understood. This study has the aim to identify early critical events for the resolution of inflammation in skin lesions using anti-TNF therapy. We used a translational approach that correlates gene expression fold change in lesional skin with the Psoriasis Area and Severity Index score decrease induced by TNF blockade after 4 weeks of treatment. Data were validated by immunofluorescence microscopy on skin biopsy specimens. We found that the anti-TNF-modulated genes that mostly associated with the clinical amelioration were Ccr7, its ligand, Ccl19, and dendritic cell maturation genes. Decreased expression of T-cell activation genes and Vegf also associated with the clinical response. More important, the down-regulation of Ccr7 observed at 4 weeks significantly correlated with the clinical remission occurring at later time points. Immunofluorescence microscopy on skin biopsy specimens showed that reduction of CCR7(+) cells and chemokine ligand (CCL) 19 was paralleled by disaggregation of the dermal lymphoid-like tissue. These data show that an early critical event for the clinical remission of psoriasis in response to TNF inhibitors is the inhibition of the CCR7/CCL19 axis and support its role in psoriasis pathogenesis.

The Use of Microbial Modifying Therapies to Prevent Psoriasis Exacerbation and Associated Cardiovascular Comorbidity.

Psoriasis has emerged as a systemic disease characterized by skin and joint manifestations as well as systemic inflammation and cardiovascular comorbidities. Many progresses have been made in the comprehension of the immunological mechanisms involved in the exacerbation of psoriatic plaques, and initial studies have investigated the mechanisms that lead to extracutaneous disease manifestations, including endothelial disfunction and cardiovascular disease. In the past decade, the involvement of gut dysbiosis in the development of pathologies with inflammatory and autoimmune basis has clearly emerged. More recently, a major role for the skin microbiota in establishing the immunological tolerance in early life and as a source of antigens leading to cross-reactive responses towards self-antigens in adult life has also been evidenced. Gut microbiota can indeed be involved in shaping the immune and inflammatory response at systemic level and in fueling inflammation in the cutaneous and vascular compartments. Here, we summarized the microbiota-mediated mechanisms that, in the skin and gut, may promote and modulate local or systemic inflammation involved in psoriatic disease and endothelial dysfunction. We also analyze the emerging strategies for correcting dysbiosis or modulating skin and gut microbiota composition to integrate systemically existing pharmacological therapies for psoriatic disease. The possibility of merging systemic treatment and tailored microbial modifying therapies could increase the efficacy of the current treatments and potentially lower the effect on patient's life quality.

Boosting NAD: An opportunity for metabolic reprogramming of Th17 cells in psoriatic disease.

Metabolic reprogramming of CD4 T cells has become an opportunity for adjunctive therapies. Here, Han et al. show that boosting NAD+ blunts systemic Th17 responses and increases antioxidant pathways through arginine and fumarate-mediated activation of NRF2 transcription factor.

Defective erythroid maturation in gelsolin mutant mice.

BACKGROUND: During late differentiation, erythroid cells undergo profound changes involving actin filament remodeling. One of the proteins controlling actin dynamics is gelsolin, a calcium-activated actin filament severing and capping protein. Gelsolin-null (Gsn(-/-)) mice generated in a C57BL/6 background are viable and fertile.1 DESIGN AND METHODS: We analyzed the functional roles of gelsolin in erythropoiesis by: (i) evaluating gelsolin expression in murine fetal liver cells at different stages of erythroid differentiation (using reverse transcription polymerase chain reaction analysis and immunohistochemistry), and (ii) characterizing embryonic and adult erythropoiesis in Gsn(-/-) BALB/c mice (morphology and erythroid cultures). RESULTS: In the context of a BALB/c background, the Gsn(-/-) mutation causes embryonic death. Gsn(-/-) embryos show defective erythroid maturation with persistence of circulating nucleated cells. The few Gsn(-/-) mice reaching adulthood fail to recover from phenylhydrazine-induced acute anemia, revealing an impaired response to stress erythropoiesis. In in vitro differentiation assays, E13.5 fetal liver Gsn(-/-) cells failed to undergo terminal maturation, a defect partially rescued by Cytochalasin D, and mimicked by administration of Jasplakinolide to the wild-type control samples. CONCLUSIONS: In BALB/c mice, gelsolin deficiency alters the equilibrium between erythrocyte actin polymerization and depolymerization, causing impaired terminal maturation. We suggest a non-redundant role for gelsolin in terminal erythroid differentiation, possibly contributing to the Gsn(-/-) mice lethality observed in mid-gestation.

Dual role of anti-TNF therapy: enhancement of TCR-mediated T cell activation in peripheral blood and inhibition of inflammation in target tissues.

The impact of anti-TNF therapy on systemic immune responses in patients has not been clearly defined. Here, we examined Th1/Th2/Th17 cytokine expression, activation and proliferation of peripheral T cells from patients with psoriasis and inflammatory bowel disease before and during anti-TNF therapy. In parallel, we calculated the correlation with the clinical response and we monitored cytokine expression in biopsies from inflamed tissues. We evidenced a dual role of TNF-blockade. In peripheral blood, it increased the expression of cytokines such as IL-17, IL-10, and IFN-γ, and enhanced the expression of activation markers and the proliferative response of CD4 T cells to TCR stimulation. By contrast, in biopsies from target tissues, TNF-blockade diminished the expression of Th17/Th1 cytokine and early inflammatory genes. Importantly, the enhanced T cell responses to TCR-stimulation did not impair the clinical response to the therapy and, in responder patients, occurred with the concomitant down-regulation of inflammatory genes in the target tissues.

UC.183, UC.110, and UC.84 Ultra-Conserved RNAs Are Mutually Exclusive with miR-221 and Are Engaged in the Cell Cycle Circuitry in Breast Cancer Cell Lines.

In the human genome, there are about 600 ultra-conserved regions (UCRs), long DNA sequences extremely conserved in vertebrates. We performed a large-scale study to quantify transcribed UCR (T-UCR) and miRNA levels in over 6000 cancer and normal tissue samples to find possible correlation between these kinds of regulatory molecules. Our analysis evidenced several non-coding RNAs showing negative co-regulation with miRNAs; among them, we focused on miR-221 to investigate any relationship with its pivotal role in the cell cycle. We have chosen breast cancer as model, using two cell lines with different phenotypes to carry out in vitro treatments with siRNAs against T-UCRs. Our results demonstrate that the expression of uc.183, uc.110, and uc.84 T-UCRs is mutually exclusive with miR-221 and is engaged in the regulation of CDKN1B expression. In addition, tests with a set of anticancer drugs, including BYL719, AZD5363, AZD8055, AZD7762, and XL765, revealed the modulation of specific T-UCRs without alteration of miR-221 levels.

Integrated metabolomic analysis and cytokine profiling define clusters of immuno-metabolic correlation in new-onset psoriasis.

The association between the metabolic profile and inflammatory cytokines in psoriasis is poorly understood. We analyzed the metabolic and cytokine/chemokine profiles in serum and skin from patients with new-onset psoriasis and healthy subjects (n = 7/group) by HR-MAS NMR and Bio-Plex immunoassay. Immuno-metabolic correlation matrix was analyzed in skin and serum to identify a potential immune-metabolic signature. Metabolomics analysis showed a significant increase in ascorbate and a decrease in scyllo-inositol, and a trend towards an increase in eight other metabolites in psoriatic skin. In serum, there was a significant increase of dimethylglycine and isoleucine. In parallel, psoriatic skin exhibited an increase of early inflammatory cytokines (IL-6, IL-8, TNF-α, IL-1ß) and correlation analysis highlighted some major clusters of immune-metabolic correlations. A cluster comprising scyllo-inositol and lysine showed correlations with T-cell cytokines; a cluster comprising serine and taurine showed a negative correlation with early inflammatory cytokines (IL-6, G-CSF, CCL3). A strong positive correlation was enlightened between glutathione and inflammatory cytokines/angiogenesis promoters of psoriasis. The integration of metabolic and immune data indicated a molecular signature constituted by IL-6, IL1-ra, DMG, CCL4, Ile, Gly and IL-8, which could discriminate patients and healthy subjects and could represent a candidate tool in the diagnosis of new-onset psoriasis.

CCR4+ Skin-Tropic Phenotype as a Feature of Central Memory CD8+ T Cells in Healthy Subjects and Psoriasis Patients.

The chemokine receptor CCR4 has emerged as a skin-homing molecule important for the migration of T cells from the blood to the dermis. From our previous data on psoriasis patients, CCR4+ memory T cells emerged as a putative recirculating population between skin and blood. Here we focused our attention on the expression of CCR4 and skin-tropic molecules in the different stages of memory T cell differentiation. We analyzed the chemokine receptor profile in CD8+ and CD4+ CD45RA-CCR7+ (TCM) and CD45RA-CCR7- (TEM) cells. Subpopulations were further divided on the basis of CD62L expression, and the distribution among the subsets of the skin-homing molecule CLA (Cutaneous Lymphocyte Antigen) was evaluated. The characterization was performed on peripheral blood mononuclear cells isolated from 21 healthy subjects and 24 psoriasis patients. The results indicate that (i) the skin-homing CCR4 marker is mainly expressed in TCM cells, (ii) CCR4+ TCM cells also express high level of CLA and that (iii) the more differentiated phenotype TEM expresses CXCR3 and CCR5 but lower level of CCR4 and CLA. This indicates that progressive stages of memory T cell differentiation have profoundly different chemokine receptor patterns, with CD8+ TCM displaying a marked skin-tropic phenotype CLA+CCR4+. Differential skin-tropic phenotype between TCM and TEM cells was observed in both healthy subjects and psoriasis patients. However, patients showed an expanded circulating population of CD8+ TCM cells with phenotype CCR4+CXCR3+ that could play a role in the pathophysiology of psoriasis and possibly in disease recurrence.

Increased frequency of activated CD8+ T cell effectors in patients with psoriatic arthritis.

The aim of this study is to identify subsets of T cells differentially represented in the circulation of patients with psoriatic arthritis and to evaluate the possibility that they can recirculate between peripheral blood and the inflamed joints. We analyzed the phenotype and cytokine expression in circulating CD8+ and CD4+ T cells in 69 subjects: 28 with cutaneous psoriasis, 15 patients with psoriatic arthritis, and 26 healthy subjects. In the circulation, the percentage of each subset was compared among the groups and correlation was calculated with the serum concentration of C-reactive protein. To investigate the migration of T cells towards the inflamed joints, we performed a transwell migration assay towards patient serum and synovial fluid. In selected patients we analyzed in parallel T cells from peripheral blood and from synovial fluid. In the circulation, we found increased percentage of CD8+ CCR6+ T cell effectors expressing CD69 and of IL-17-producing T cells in patients with psoriatic arthritis. CD8+ effector/effector memory T cells showed increased migration towards synovial fluid. Finally, in synovial fluid we found accumulation of CXCR3+ CD8+ T cells and CD69+ cells. CD4+ T cells in the two compartments shared many similarities with CD8+ T cells. The results indicate a role for memory T cell effectors in systemic and joint manifestations of psoriatic arthritis.

Targeted delivery of murine IFN-gamma using a recombinant fowlpox virus: NK cell recruitment to regional lymph nodes and priming of tumor-specific host immunity.

Interferon-gamma (IFN-gamma) is a proinflammatory cytokine that also acts as a potent immunomodulatory agent. In this study, a replication-deficient recombinant avian (fowlpox) virus was engineered to express the murine IFN-gamma gene (rF-MuIFN-gamma) with the rationale of delivering concentrated levels of the cytokine to a local tissue microenvironment. Subcutaneous (s.c.) rF-MuIFN-gamma administration resulted in IFN-gamma production that (1) was restricted to the tissue microenvironment of the injection site and (2) was biologically active, as evidenced by a significant increase of class I MHC expression levels in s.c. growing tumors following rF-MuIFN-gamma administration. Infection of a highly tumorigenic murine cell line, MC38, with rF-MuIFN-gamma functioned as an effective tumor cell-based vaccine by protecting mice from the formation of primary tumors and from subsequent tumor challenge. The cell-based vaccine was completely ineffective if mice were vaccinated with MC38 cells either pretreated with rIFN-gamma or infected with the wild-type fowlpox virus (FP-WT). Analysis of the regional lymph nodes draining the site of injection of the rF-MuIFN-gamma-based tumor cell vaccine revealed the presence of tumor-specific cell lysis (CTL) as well as a significant amount of lysis directed at natural killer (NK)-sensitive YAC-1 cells. Flow cytometric analyses coupled with functional assays confirmed the sustained presence of NK1.1(+) cells within those draining lymph nodes for up to 5 days after rF-MuIFN-gamma injection. Mice treated with NK cell-depleting antibodies prior to the injection of the rF-MuIFN-gamma-infected MC38 tumor cells were not protected from primary tumor growth; analysis of the lymph nodes draining the injection site in NK-depleted mice revealed an accompanying loss of the tumor-specific CTL activity. The findings provide evidence that NK cells, known for their contributions to host innate immunity, also provide immunoregulatory signals required for the development of an adaptive immune response, which, in turn, protected vaccinated mice against tumor growth.

T Cell Hierarchy in the Pathogenesis of Psoriasis and Associated Cardiovascular Comorbidities.

The key role of T cells in the pathogenesis of cutaneous psoriasis has been well described in the last decade and the knowledge of the relative role of the different subsets of T cells in psoriasis pathogenesis has considerably evolved. Now, it is clear that IL-17A-producing T cells, including Th17/Tc17, have a central role in the pathogenesis of cutaneous psoriasis and therapies blocking the IL-17A pathway show high clinical efficacy. By contrast, the contribution of IFNγ-producing T cells has progressively become less clear because of the lack of efficacy of anti-IFNγ antibodies in clinical studies. In parallel, the role of CD8+ T cells specific for self-antigens has been revived and increasing evidence now indicates that in psoriatic skin the majority CD8+ T cells are present in the form of epidermal tissue-resident memory T cells. In the last years it also emerged the possibility of a contribution of T cell recirculation in the pathogenesis of psoriasis and its systemic manifestations. The aim of this review is to define a hierarchy for the different subsets of T cells in the T cell-mediated inflammatory cascade in psoriatic skin. This analysis will possibly help to distinguish the subsets that initiate the disease, those involved in the establishment of the self-sustaining amplification loop that leads to the cutaneous clinical manifestations and finally the subsets that act as downstream players in established lesions. Specific T cell subpopulations finally will be considered for their possible role in propagating inflammation at distant sites and for representing a link with systemic inflammation and cardiovascular comorbidities.

Identification of an interferon-gamma-inducible carcinoembryonic antigen (CEA) CD8(+) T-cell epitope, which mediates tumor killing in CEA transgenic mice.

This study describes a CD8(+) T-cell line specific for a MHC class I-restricted carcinoembryonic antigen (CEA) epitope, residues 526-533, isolated from CEA transgenic (CEA.Tg) mice immunized with a recombinant vaccinia-CEA vaccine. Incubation of splenocytes from the immune CEA.Tg mice with the CEA(526-533) peptide resulted in the outgrowth of low-avidity CD8(+) T cells, which produced IFN-gamma and mediated perforin-dependent tumor cell lysis. However, the CEA peptide-specific T cells killed CEA-expressing murine colorectal tumor cells only after pretreatment of the targets with murine IFN-gamma (muIFN-gamma), and lysis was H-2D(b)-restricted and involved the Fas-FasL-mediated cytotoxic pathway. When the CEA peptide-specific T cells were used as in vivo effectors in adoptive T-cell transfer studies, muIFN-gamma treatment of the CEA.Tg mice was again required for T-cell-dependent growth suppression of CEA-expressing metastatic tumors. The results indicate that (a) vaccination of mice carrying the human CEA gene with recombinant vaccinia-CEA generates a CEA epitope-specific, CD8-dependent CTL response, (b) CEA, a normal, tissue-specific antigen, can also serve as a target for antitumor immunity after the adoptive transfer of CEA peptide-specific T cells, and (c) muIFN-gamma might be an effective cancer vaccine adjuvant by virtue of its ability to augment the susceptibility of tumor targets to cell-mediated lysis.