Phenotypic Alterations Involved in CD8+ Treg Impairment in Systemic Sclerosis.

Systemic sclerosis (SSc) is a connective tissue disease characterized by tissue fibrosis, vasculopathy, and autoimmunity. Although the exact pathogenetic mechanisms behind SSc remain to be fully elucidated, a great deal of evidence suggests the existence of an unbalanced ratio between the effector and regulatory arms of the immune system. With regard to the T regulatory (Treg) compartment, we observed that CD8+ Treg subsets display functional defects in SSc-affected patients. Since CD127 down-modulation and CD39 upregulation have been observed on Treg subsets, the phenotypic expression of these molecules was analyzed on the CD8+CD28- Treg precursors and on CD8+ Treg cells generated in vitro through interleukin-10 commitment. Immunophenotypic data from SSc patients were compared to those obtained from healthy subjects. The analyses performed on ex vivo-isolated CD8+CD28- Treg precursors did not show any significant differences in CD39 or CD127 expression as compared to values obtained from healthy donors. On the contrary, in vitro-generated CD8+ Tregs obtained from SSc patients displayed reduced expression of the CD39 molecule as compared to controls. Moreover, the percentage of CD127+ cells was significantly higher in in vitro-generated CD8+ Tregs from SSc patients compared to CD8+ Tregs obtained from healthy donors. Taken together, these findings may indicate an impairment of maturation processes affecting CD8+ Treg cells in SSc patients. This impairment of maturation involves phenotypic alterations that are mainly characterized by a deficient CD39 upregulation and a lack of down-modulation of the CD127 molecule.

AIRE polymorphism, melanoma antigen-specific T cell immunity, and susceptibility to melanoma.

AIRE is involved in susceptibility to melanoma perhaps regulating T cell immunity against melanoma antigens (MA). To address this issue, AIRE and MAGEB2 expressions were measured by real time PCR in medullary thymic epithelial cells (mTECs) from two strains of C57BL/6 mice bearing either T or C allelic variant of the rs1800522 AIRE SNP. Moreover, the extent of apoptosis induced by mTECs in MAGEB2-specific T cells and the susceptibility to in vivo melanoma B16F10 cell challenge were compared in the two mouse strains.The C allelic variant, protective in humans against melanoma, induced lower AIRE and MAGEB2 expression in C57BL/6 mouse mTECs than the T allele. Moreover, mTECs expressing the C allelic variant induced lower extent of apoptosis in MAGEB2-specific syngeneic T cells than mTECs bearing the T allelic variant (p < 0.05). Vaccination against MAGEB2 induced higher frequency of MAGEB2-specific CTL and exerted higher protective effect against melanoma development in mice bearing the CC AIRE genotype than in those bearing the TT one (p < 0.05). These findings show that allelic variants of one AIRE SNP may differentially shape the MA-specific T cell repertoire potentially influencing susceptibility to melanoma.

Increased CD38 expression on T lymphocytes as a marker of HIV dissemination into the central nervous system.

Cross-sectional analysis on 20 HIV-1 patients with neurological symptoms admitted to two infectious disease units. Cut-off of HIV-RNA (VL) was 20 copies/ml for plasma and cerebral spinal fluid (CSF). Flow cytometry was used to analyze the phenotype of circulating and CSF T lymphocytes. CD38 mean fluorescence intensity (MFI) was higher on circulating CD4+T lymphocytes from patients with VL>20 copies/ml in plasma (P=0.001) or CSF (P=0.001). The frequency of circulating CD8+CD38+T cells and CD38 MFI on these cells were higher in patients with VL>20 copies/ml than in those with undetectable plasma VL (P=0.030 and P=0.023). The frequency of CSF CD4+CD38+T, as well as their CD38 and CD95 MFI, were increased in patients with detectable than non-detectable plasma VL (P=0.01, P=0.03, and P=0.05). The % CD38+CD8+T in CSF correlated with time of virological suppression (ρ=-0.462, P=0.040) and the CNS penetration-effectiveness (CPE) score (ρ=-0.467, P=0.038). In conclusion, (a) the expression of CD38+ on both CD4+, CD8+T lymphocytes from peripheral blood and CSF discriminated between viremic and non-viremic patients and (b) T cell activation/apoptosis markers inversely correlated with CPE to remark the importance for therapy to restore immunological functions.

Early and repeated IgG1Fc-pCons chimera vaccinations (GX101) improve the outcome in SLE-prone mice.

A previous study showed that a tolerogenic gene vaccine based on a IgG1Fc-pCons chimera (here named GX101) protects NZB/NZW mice from SLE development. The present study was aimed at identifying the most effective schedule of immunization and the possible involvement of CD4(+) Foxp3(+) Treg in the mechanism of action, in view of its eventual translation to the human studies. NZB/NZW mice were vaccinated with B lymphocytes made transgenic by spontaneous transgenesis with a gene coding for a chimeric IgG1Fc-pCons construct. Different schedules of vaccination were set in relation to the timing and number of administrations. Survival, proteinuria levels, and CD4(+) Foxp3(+) Treg frequency were monitored during the full experiments. GX101-treated mice showed delayed disease onset and delayed mortality than controls. GX101 effects were implemented by early as well as repeated vaccine administrations. GX101 vaccination was associated with increased frequencies of CD4(+) CD25(+) Foxp3(+) Treg with respect to controls. This study demonstrates that early and repeated immunizations with GX101 vaccine provide a better outcome than late or single vaccine administration regarding onset/development in SLE-prone mice, acting as a possible disease-modifying approach. Vaccine effects are likely related to CD4(+) Foxp3(+) Treg cell expansion.

Comparative analysis of cancer vaccine settings for the selection of an effective protocol in mice.

BACKGROUND: Cancer vaccines are considered a promising therapeutic approach. However, their clinical results are not yet satisfactory. This may be due to the the difficulty of selection of an efficient tumor associated antigen (TAA) and immunization protocol. Indeed, the weak antigenicity of many TAA impairs the design of robust procedures, therefore a systematic analysis to identify the most efficient TAA is mandatory. Here, we performed a study to compare different gp100 vaccination strategies to identify the best strategy to provide a 100% protection against experimental melanoma in a reproducible manner. METHODS: C57BL/6J mice were challenged subcutaneously with B16F10 melanoma cells, after vaccination with: a) mouse or human gp10025-33 peptide plus CpG adjuvant; b) mouse or human gp100 gene; c) mouse or human gp10025-33 peptide-pulsed dendritic cells (DC). Alternatively, a neutralizing anti-IL-10 monoclonal antibody (mAb) was subcutaneously administered at the site of tumor challenge to counteract regulatory cells. Finally, combinatorial treatment was performed associating human gp10025-33 peptide-pulsed DC vaccination with administration of the anti-IL-10 mAb. RESULTS: Vaccination with human gp10025-33 peptide-pulsed DC was the most effective immunization protocol, although not achieving a full protection. Administration of the anti-IL-10 mAb showed also a remarkable protective effect, replicated in mice challenged with a different tumor, Anaplastic Large Cell Lymphoma. When immunization with gp10025-33 peptide-pulsed DC was associated with IL-10 counteraction, a 100% protective effect was consistently achieved. The analysis on the T-cell tumor infiltrates showed an increase of CD4+granzyme+ T-cells and a decreased number of CD4+CD25+Foxp3+ Treg elements from mice treated with either gp10025-33 peptide-pulsed DC vaccination or anti-IL-10 mAb administration. These data suggest that processes of intratumoral re-balance between effector and regulatory T cell subpopulations may play a critical protective role in immunotherapy protocols. CONCLUSIONS: Here we demonstrate that, in the setting of a cancer vaccine strategy, a comparative analysis of different personalized approaches may favour the unveiling of the most effective protocol. Moreover, our findings suggest that counteraction of IL-10 activity may be critical to revert the intratumoral environment promoting Treg polarization, thus increasing the effects of a vaccination against selected TAA.

Fingolimod modulates peripheral effector and regulatory T cells in MS patients.

Multiple sclerosis (MS) is a complex neurological disease where, in genetically predisposed individuals, the unbalanced interplay between pathogenic and regulatory T cells will result in the progression of the autoimmune assault to neural antigens. Fingolimod (FTY720), an oral sphingosine 1-phosphate modulator recently approved for the treatment of MS, inhibits the egress of T cells from lymph nodes acting specifically on naïve and memory T cells and sparing effector T cells. Here we characterized IL-17 and IFNγ producing effector CD4 and CD8 positive T cells as well as CD4 positive CD25(high)CD127(low) regulatory T cells in MS patients before and 1 month after treatment was started. We observed that fingolimod did not significantly affect the percentage of CCR6 and CD161 positive T cells in both CD4 and CD8 compartments. In contrast, it significantly reduced the levels of both CD4+ CCR6+ CD161+ and CD8+ CCR6+ CD161+ producing IFNγ alone or in combination with IL-17. The percentage of IL-17 secreting cells in both subsets was affected by the treatment to a lesser extent. Finally, we observed that CD4+ CD25(high)CD127(low) regulatory T cells were decreased in MS patients compared to healthy controls and fingolimod significantly increased their frequencies. All together these findings demonstrate that fingolimod functionally modulates the ability of potentially pathogenic effector cells to produce relevant pro-inflammatory cytokines and increases the number of circulating regulatory T cells possibly contributing in restoring a balance between these populations.

A multi-peptide, dual-adjuvant telomerase vaccine (GX301) is highly immunogenic in patients with prostate and renal cancer.

BACKGROUND: Anti-tumor vaccination is a new frontier in cancer treatment applicable to immunogenic neoplasms such as prostate and renal cancers. GX301 is a vaccine constituted by four telomerase peptides and two adjuvants, Montanide ISA-51 and Imiquimod. OBJECTIVE: The aim of this study was to analyze safety and tolerability of GX301 in an open-label, phase I/II trial. Immunological and clinical responses were also evaluated as secondary endpoints. EXPERIMENTAL DESIGN: GX301 was administered by intradermally injecting 500 µg of each peptide (dissolved in Montanide ISA-51) in the skin of the abdomen. Imiquimod was applied as a cream at the injection sites. The protocol included 8 administrations at days 1, 3, 5, 7, 14, 21, 35, 63. Eligible patients were affected with stage IV prostate or renal cancer resistant to conventional treatments. Patients were clinically and immunologically monitored up to 6 months from the first immunization. RESULTS: No grade 3-4 adverse events were observed. Evidence of vaccine-specific immunological responses was detected in 100 % of patients. Disease stabilization occurred in 4 patients. Prolonged progression-free survival and overall survival were observed in patients showing a full pattern of vaccine-specific immunological responses. CONCLUSION: GX301 demonstrated to be safe and highly immunogenic. Further studies are needed to determine its clinical efficacy.

Immunological profile of Fanconi anemia: a multicentric retrospective analysis of 61 patients.

In this study, the immunological status of 61 patients with Fanconi anemia (FA) with advanced marrow failure before hematopoietic stem cell transplantation was analyzed by assessing the phenotype of peripheral blood lymphocytes, serum immunoglobulin (Ig) levels, and inflammatory cytokines. In patients with FA, total absolute lymphocytes (P < 0.0001), B cells (P < 0.0001), and NK cells (P = 0.003) were reduced when compared with normal controls. T cells (CD3), that is, cytotoxic T cells, naïve T cells, and regulatory T cells, showed a relative increase when compared with controls. Serum levels of IgG (P < 0.0001) and IgM (P = 0.004) were significantly lower, whereas IgA level was higher (P < 0.0001) than in normal controls. TGF-ß (P = 0.007) and interleukin (IL)-6 (P = 0.0007) levels were increased in the serum of patients when compared with controls, whereas sCD40L level decreases (P < 0.0001). No differences were noted in the serum levels of IL-1ß, IL-2, IL-4, IL-10, IL-13, IL-17, and IL-23 between FA subjects and controls. This comprehensive immunological study shows that patients with FA with advanced marrow failure have an altered immune status. This is in accordance with some characteristics of FA such as the proinflammatory and proapoptotic status. In addition, B lymphocyte failure may make tight and early immunological monitoring advisable.

CD39 is highly involved in mediating the suppression activity of tumor-infiltrating CD8+ T regulatory lymphocytes.

CD39 is an ectoenzyme, present on different immune cell subsets, which mediates immunosuppressive functions catalyzing ATP degradation. It is not known whether CD39 is expressed and implicated in the activity of CD8+ regulatory T lymphocytes (Treg). In this study, CD39 expression and function was analyzed in both CD8+ and CD4+CD25(hi) Treg from the peripheral blood of healthy donors as well as from tumor specimens. CD39 was found expressed by both CD8+ (from the majority of healthy donors and tumor patients) and CD4+CD25(hi) Treg, and CD39 expression correlated with suppression activity mediated by CD8+ Treg. Importantly, CD39 counteraction remarkably inhibited the suppression activity of CD8+ Treg (both from peripheral blood and tumor microenvironment) suggesting that CD39-mediated inhibition constitutes a prevalent hallmark of their function. Collectively, these findings, unveiling a new mechanism of action for CD8+ Treg, provide new knowledge on intratumoral molecular pathways related to tumor immune escape, which could be exploited in the future for designing new biological tools for anticancer immune intervention.

Indoleamine 2,3 dioxygenase gene polymorphisms correlate with CD8+ Treg impairment in systemic sclerosis.

Systemic sclerosis (SSc) is characterized by tissue fibrosis, vasculopathy and autoimmunity. Indoleamine 2,3 dioxygenase (IDO) plays a pivotal role in immunological tolerance modulating regulatory T cell (Treg) generation and function. Single nucleotide polymorphisms (SNPs) of IDO gene could impact on Treg function and predispose to autoimmunity. Here, the existence of an association between specific IDO SNPs and SSc was analyzed. Five specific SNPs in IDO gene were searched in 31 SSc patients and 37 healthy controls by gene sequencing or restriction fragment length polymorphism. The function of both CD4+CD25+ and CD8+ Treg from SSc patients was analyzed by proliferation suppression assay. SNP rs7820268 was statistically more frequent in SSc patients than in controls. Notably, SSc patients bearing the T allelic variant of the rs7820268 SNP showed impaired CD8+ Treg function. Our unprecedented data show that a specific IDO gene SNP is associated with an autoimmune disease such as SSc.

Th17 and regulatory T lymphocytes in primary biliary cirrhosis and systemic sclerosis as models of autoimmune fibrotic diseases.

Fibrotic autoimmune diseases are characterized by an inflammatory process in which fibrogenic cytokines, such as TGFß and IL6, have a major role. Interestingly, these cytokines are also involved in the generation and function of both an effector T lymphocyte subpopulation, the Th17 cells, and the regulatory T lymphocytes (Treg). These evidences raised the hypothesis that an unbalanced equilibrium induced by the overproduction of the fibrogenic cytokines may have pathogenic relevance in fibrotic autoimmune diseases. On this basis, this review analyzes the available data concerning Th17 and Treg generation and function in two representative fibrotic autoimmune diseases, primary biliary cirrhosis (PBC) and systemic sclerosis (SSc), as models for organ-specific and systemic diseases, respectively. With regard to the Th17 cells, their expansion was found to be a common feature associated with a relative contraction of Th1 immune responses. Concerning to the regulatory T cell compartment, quantitative and qualitative alterations were observed in both diseases. However, while PBC patients showed defects only in the CD8+ Treg subset, SSc patients demonstrated abnormalities regarding to both the CD4+CD25+ and the CD8+ Treg subpopulations. Hence, the CD8+ Treg subset seems to be the most involved in the pathogenic cascade leading to fibrotic disease onset and maintenance. Collectively, the reviewed data support the concept that altered homeostasis between effector and regulatory T cell circuits is present in fibrotic autoimmune diseases and that the major factors responsible for such disequilibrium are Th17 cells in the effector arm and CD8+ Treg in the regulatory arm.

Abscisic acid ameliorates the systemic sclerosis fibroblast phenotype in vitro.

The phytohormone abscisic acid (ABA) has been recently identified as an endogenous hormone in humans, regulating different cell functions, including inflammatory processes, insulin release and glucose uptake. Systemic sclerosis (SSc) is a chronic inflammatory disease resulting in fibrosis of skin and internal organs. In this study, we investigated the effect of exogenous ABA on fibroblasts obtained from healthy subjects and from SSc patients. Migration of control fibroblasts induced by ABA was comparable to that induced by transforming growth factor-ß (TGF-ß). Conversely, migration toward ABA, but not toward TGF-ß, was impaired in SSc fibroblasts. In addition, ABA increased cell proliferation in fibroblasts from SSc patients, but not from healthy subjects. Most importantly, presence of ABA significantly decreased collagen deposition by SSc fibroblasts, at the same time increasing matrix metalloproteinase-1 activity and decreasing the expression level of tissue inhibitor of metalloproteinase (TIMP-1). Thus, exogenously added ABA appeared to revert some of the functions altered in SSc fibroblasts to a normal phenotype. Interestingly, ABA levels in plasma from SSc patients were found to be significantly lower than in healthy subjects. UV-B irradiation induced an almost 3-fold increase in ABA content in SSc cultures. Altogether, these results suggest that the fibrotic skin lesions in SSc patients could benefit from exposure to high(er) ABA levels.

Cyclophosphamide inhibits the generation and function of CD8(+) regulatory T cells.

CD8(+) regulatory T cells (Treg) and CD4(+)CD25(+) Treg infiltrate human cancers, thus favoring tumor immune escape. Therefore, in the setting of antitumor therapeutic protocols, it is important to associate antitumor treatment with agents that are able to inhibit Treg function. Cyclophosphamide (CY) has been demonstrated to be effective in counteracting CD4(+)CD25(+) Treg activity. Hence, we tested its inhibitory efficacy on human CD8(+) Treg. Because CY is a prodrug, 4-hydroperoxycyclophosphamide (4-HC), a derivative of CY that in aqueous solution is converted to 4-hydroxycyclophosphamide, an active metabolite of CY, was used. 4-HC significantly inhibited CD8(+) Treg generation and function but only at the higher tested concentration (0.5 µg/mL), that is, in the therapeutic range of the drug. The lower 4-HC concentration tested (0.1 µg/mL) was almost ineffective. 4-HC inhibitory effects were related to apoptosis/necrosis induction. When CD8(+)CD28(+) non-Treg were analyzed for comparative purposes, significantly lower cytotoxic rates among these cells were observed than among CD8(+) Treg, which were differentiated because they did not express the CD28 molecule. These data demonstrate that CD8(+) Treg are inhibited through cytotoxic phenomena by CY, thus supporting the use of this drug at adequate concentrations and schedules of administration as a Treg inhibitor in combinatorial chemo- or immunotherapeutic anticancer protocols.

Increase in IL-6 levels among major depressive disorder patients after a 6-week treatment with duloxetine 60 mg/day: a preliminary observation.

BACKGROUND: Immune modifications, including changes in interleukin (IL)-6 levels, have often been observed in major depressive disorder (MDD) during treatment with selective serotonin reuptake inhibitors (SSRIs) or the serotonin norepinephrine reuptake inhibitor (SNRI) venlafaxine. Nevertheless, no equivalent observation for the SNRI duloxetine has been made to date. METHOD: Sixteen patients diagnosed with MDD and an actual major depressive episode according to DSM-IV criteria and 16 healthy controls entered a 6-week trial with duloxetine 60 mg/day. All subjects (n = 32) were assessed using the Hamilton Depression Rating Scale (HAM-D), the Young Mania Rating Scale (YMRS), and were monitored for IL-6 levels both at baseline and at week 6. Blood samples for IL-6 levels were evaluated by ELISA. RESULTS: After 6 weeks of treatment, the mean total scores for HAM-D declined both in the depressed and control groups, while IL-6 modification showed an opposite trend both in depressed (12.38 ± 19.80 to 19.73 ± 18.94 pg/mL) and control subjects (12.25 ± 21.12 to 17.63 ± 20.44 pg/mL), as did YMRS (ns), although none of the subjects switched to (hypo)mania. Of note, IL-6 levels increased significantly only in the responders subgroup (n = 9; P = 0.012). CONCLUSION: The small sample size and weak design of this study limit the validity of our results, which should be regarded as preliminary only. Nonetheless, the trend of increasing IL-6 levels observed in responder patients treated with duloxetine should prompt further controlled, extended studies with larger samples, with the specific aim of better assessing a putative differential role of norepinephrinergic antidepressant stimulation of serotonergic reuptake inhibition in determining modifications in IL-6 levels. Ideally, more accurate replication studies may contribute to further understanding of the complex interaction of mood, antidepressant response, and the immune system.

Alteration of Th17 and Treg cell subpopulations co-exist in patients affected with systemic sclerosis.

Aim of the study has been to understand the relationship between TH17 and Treg cell subsets in patients affected with systemic sclerosis (SSc). Phenotypes and functions of Th17 and Treg cell subsets were analyzed in a series of 36 SSc patients. Th17 cell concentration in the peripheral blood was found to be increased in SSc patients with respect to healthy controls independently from type or stage of disease. After PBMC stimulation with a polyclonal stimulus or Candida albicans antigens the frequency of Th17 T cell clones was significantly higher in SSc patients with respect to controls suggesting the skewing of immune response in SSc patients toward Th17 cell generation/expansion. Concerning the Treg compartment, both CD4+CD25+ and CD8+CD28- Treg subsets showed quantitative and qualitative alteration in the peripheral blood of SSc patients. Collectively, these data highlight the existence of an imbalanced ratio between Th17 and Treg cell subsets in SSc patients.

Phenotypical and functional alterations of CD8 regulatory T cells in primary biliary cirrhosis.

The mechanisms that lead to loss of tolerance in autoimmune disease have remained both elusive and diverse, including both genetic predisposition and generic dysregulation of critical mononuclear cell subsets. In primary biliary cirrhosis (PBC), patients exhibit a multilineage response to the E2 component of pyruvate dehydrogenase involving antibody as well as autoreactive CD4 and CD8 responses. Recent data from murine models of PBC have suggested that a critical mechanism of biliary destruction is mediated by liver-infiltrating CD8 cells. Further, the number of autoreactive liver-infiltrating CD4 and CD8 cells is significantly higher in liver than blood in patients with PBC. Based on this data, we have studied the frequencies and phenotypic characterization of both CD4 and CD8 regulatory T cell components in both patients with PBC and age-sex matched controls. Our data is striking and indicate that CD8 Treg populations from PBC patients, but not controls, have significant phenotypic alterations, including increased expression of CD127 and reduced CD39. Furthermore, in vitro induction of CD8 Tregs by incubation with IL10 is significantly reduced in PBC patients. Importantly, the frequencies of circulating CD4+CD25+ and CD8+ and CD28- T cell subpopulations are not significantly different between patients and controls. In conclusion, these data identify the CD8 Treg subset as a regulatory T cell subpopulation altered in patients with PBC.

Macrophage-inflammatory protein-3alpha/CCL-20 is transcriptionally induced by the iron chelator desferrioxamine in human mononuclear phagocytes through nuclear factor (NF)-kappaB.

Alterations in iron availability can trigger pro-inflammatory signals in various cell types. We demonstrate that desferrioxamine (DFX), an iron chelator used in clinics for the treatment of iron overload, neoplasias, and Alzheimer disease, stimulates the expression and secretion of CCL20, a chemoattractant for immature dendritic cells, activated/memory T lymphocytes, and naive B cells, in primary human monocytes and monocyte-derived macrophages. Iron chelation was part of the mechanism by which DFX induced CCL20, because addition of iron sulfate counteracted its stimulatory effects. Functional studies of the CCL20 promoter, using a series of 5'-deleted and mutated reporter constructs, demonstrated that CCL20 mRNA induction was dependent on gene transcription activation and mediated by the NF-kappaB pathway. The NF-kappaB element located at position -92/-82 of the CCL20 promoter was required for gene transactivation by DFX because: (i) transcription was abrogated by a 3bp mutation of the NF-kappaB-binding motif; (ii) treatment with DFX increased specific NF-kappaB binding to this sequence. Nuclear translocation of both NF-kappaBp65 and NF-kappaBp50 family members was increased in response to DFX and associated with I-kappaBalpha degradation, suggesting a role for these subunits in CCL20 promoter transactivation. In conclusion, this study provides the first evidence that iron chelation can transcriptionally induce CCL20 in mononuclear phagocytes and identify the NF-kappaB binding site as a regulatory sequence of the CCL20 promoter that is activated by iron deprivation. These results add new insights into our understanding of the mechanisms by which iron perturbations affect mononuclear phagocyte immune functions and regulate inflammatory responses.

Peripheral Th-17 cells in allergic rhinitis: New evidence.

BACKGROUND: Th17 is a subset of T helper lymphocytes exerting inflammatory activities. Recently, it has been reported that serum IL-17 levels are high in patients with severe birch allergy. AIM OF THE STUDY: It was to compare the cytokine profile and the frequency of peripheral allergen-specific T helper producing IL-17 in patients with allergic rhinitis. METHODS: Twelve patients with persistent allergic rhinitis due to pollens and 5 healthy non-allergic subjects were evaluated during the pollen season. Th17 were evaluated by intracellular staining in T cell compartment ex-vivo and after short activation by allergens and control antigens. RESULTS: Ex-vivo PBMNC evaluation showed that allergic patients had higher frequencies of IL-17 producing T cells. Functional analysis after antigen-specific CD4+ T cell expansion demonstrated that allergic patients had higher frequencies of IL-17 producing T cells than normal subjects. CONCLUSION: This preliminary study contributes to the knowledge concerning the possible role of Th-17 cells in the response to allergens.

Vdelta1 T lymphocytes producing IFN-gamma and IL-17 are expanded in HIV-1-infected patients and respond to Candida albicans.

In early HIV-1 infection, Vdelta1 T lymphocytes are increased in peripheral blood and this is related to chemokine receptor expression, chemokine response, and recirculation. Herein we show that, at variance with healthy donors, in HIV-1-infected patients ex vivo-isolated Vdelta1 T cells display cytoplasmic interferon-gamma (IFN-gamma). Interestingly, these cells coexpress cytoplasmic interleukin-17 (IL-17), and bear the CD27 surface marker of the memory T-cell subset. Vdelta1 T cells, isolated from either patients or healthy donors, can proliferate and produce IFN-gamma and IL-17 in response to Candida albicans in vitro, whereas Vdelta2 T cells respond with proliferation and IFN-gamma/IL-17 production to mycobacterial or phosphate antigens. These IFN-gamma/IL-17 double-producer gammadelta T cells express the Th17 RORC and the Th1 TXB21 transcription factors and bear the CCR7 homing receptor and the CD161 molecule that are involved in gammadelta T-cell transendothelial migration. Moreover, Vdelta1 T cells responding to C albicans express the chemokine receptors CCR4 and CCR6. This specifically equipped circulating memory gammadelta T-cell population might play an important role in the control of HIV-1 spreading and in the defense against opportunistic infections, possibly contributing to compensate for the impairment of CD4(+) T cells.

Advancements on phenotypic and functional characterization of non-antigen-specific CD8+CD28- regulatory T cells.

Among the different regulatory T lymphocyte (Treg) subpopulations, non-antigen-specific CD8+CD28- Treg (CD8+CD28- Treg) have been characterized for being involved in the pathogenesis of autoimmune diseases and cancer. A better phenotypic and functional characterization of this regulatory T-cell subset could help in identifying modulators of their activity with therapeutic finalities. The results of the present work show that Foxp3, a transcriptional marker of natural CD4+CD25+ Treg, is not expressed by CD8+CD28- Treg, thus indicating different origin and pathways of function for the latter with respect to the former regulatory cell type. Moreover, the results underline that the glucocorticoid induced TNF receptor is involved in generation processes but not in suppressor function of CD8+CD28- Treg. Phenotypic analyses demonstrate that, during their commitment from circulating nonregulatory CD8+CD28- T lymphocytes to Treg (an interleukin-10-dependent process), these cells downmodulate the IL7-receptor, thus differentiating them from long-lived, memory CD8+ T lymphocytes. Interestingly, CD8+CD28- Treg have been found to be resistant to the inhibitory effects of methylprednisolone, one of the most frequently administered corticosteroid drug used in therapy for immunosuppressive purposes.