Adaptive Immunity

2013 Journal of Investigative Dermatology  
Japan Thymic stromal lymphopoietin (TSLP) is produced by epidermal keratinocytes, and it induces Th2mediated inflammation. TSLP expression is enhanced in lesions with atopic dermatitis, and is a therapeutic target. Antimycotic agents improve the symptoms of atopic dermatitis. We examined whether antimycotics suppress TSLP expression in human keratinocytes. Normal human keratinocytes were incubated with polyinosinic-polycytidylic acid (poly I:C) plus IL-4 in the presence of antimycotics. TSLP
more » ... ression was analyzed by performing ELISA and real time PCR. Luciferase assays were performed to analyze NF-κB activity. IκBα degradation was analyzed by performing western blot analysis. Poly I:C plus IL-4 increased the secretion and mRNA levels of TSLP, which was suppressed by an NF-κB inhibitor, and also enhanced NF-κB transcriptional activities and induced the degradation of IκBα in keratinocytes. The antimycotics itraconazole, ketoconazole, luliconazole, terbinafine, butenafine, and amorolfine suppressed the secretion and mRNA expression of TSLP, NF-κB activity, and IκBα degradation induced by poly I:C plus IL-4. These suppressive effects were similarly manifested by 15-deoxy-A-12,14-PGJ2 (15d-PGJ2), a PGD2 metabolite. Antimycotics increased the release of 15d-PGJ2 from keratinocytes and decreased the release of thromboxane B2, a thromboxane A2 metabolite. Antimycotic-induced suppression of TSLP production and NF-κB activity was counteracted by an inhibitor of lipocalin type-PGD synthase. In conclusion, antimycotics itraconazole, ketoconazole, luliconazole, terbinafine, butenafine, and amorolfine may suppress poly I:C plus IL-4-induced production of TSLP by inhibiting NF-κB via increasing 15d-PGJ2 production in the keratinocytes. These antimycotics may block the overexpression of TSLP in lesions with atopic dermatitis. Defective development and function of CD4+CD25high+Foxp3+ regulatory T cells (Tregs) contribute to the pathogenesis of psoriasis and other autoimmune diseases. Little is known about the influence of adhesions molecules on the differentiation of Foxp3+ Tregs into pro-inflammatory Th17 cells, occurring in lesional skin and blood of psoriasis patients. In the CD18hypo PL/J mouse model of psoriasis reduced expression of CD18/β2 integrin to 2-16% of wildtype levels is associated with progressive loss of Tregs, impaired cell-cell contact between Tregs and dendritic cells (DCs) as well as Treg dysfunction as reported earlier. In the present investigation, Tregs derived from CD18hypo PL/J mice were analyzed for their propensity to differentiate into Rorγt+ IL-17 producing Th17 cells in vivo and in in vitro Treg-DC co-cultures. Adoptively transferred CD18hypo PL/J Tregs were more inclined towards conversion into IL-17 producing Th17 cells in vivo in an inflammatory as well as non-inflammatory environment compared to CD18wt PL/J Tregs. Addition of neutralizing antibody against CD18 to Treg-DC co-cultures in vitro promoted conversion of CD18wt PL/J Tregs to Th17 cells in a dose-dependent manner similar to conversion rates of CD18hypo PL/J Tregs. Reduced thymic output of nTregs and peripheral conversion of Tregs into Th17 cells therefore both contribute to the loss of Tregs and the psoriasiform dermatitis observed in CD18hypo PL/J mice mice. Our data overall indicate that CD18 expression levels impact Treg development as well as Treg plasticity and that differentiation of Tregs into IL-17 producing Th17 cells is distinctly facilitated by a subtotal deficiency of CD18. Background. Atopic dermatitis (AD) is a recurrent pruritic and chronic inflammatory disease. Qingpeng ointment (QP) is a traditional Chinese medicine which has been used in the treatment of AD in China, but the mechanism is unknown. Aim. To analyze the anti-inflammatory effects of QP on induced AD in mice. Methods. AD lesions were induced in 108 eight-week-old BALB/c mice by repeated application of 2, 4-dinitrofluorobenzene on shaved backs and the mice were then equally divided into 6 groups to untreated group (model control), different concentration of QP (100%, 75% and 50%) treated group, vehicle of QP treated group and Mometasone Furoate cream (MF) (positive control) treated group respectively, and treated for two weeks. Eighteen mice receiving no sensitization or treatment served as blank normal control. Macroscopic and microscopic changes of the skin lesions were observed after the treatment. The levels of serum immunoglobulin (Ig) E, tissue interferon (IFN)-γ, interleukin (IL)-4 and IL-17A protein were measured with Enzyme-Linked Immunosorbnent Assay (ELISA) and tissue mRNA expression of IL-4, IFN-γ and IL-17A was measured with quantitative real-time polymerase chain reaction (PCR). Results. Similar to MF, QP could significantly inhibit the induced AD lesions in a dose-related pattern. Levels of serum IgE, tissue IL-4 and the mRNA expression of IL-17A was suppressed by QP treatment while the tissue IFN-γ was increased. Conclusions. QP could inhibit hapten induced AD lesions in mice by at least inhibition of IL-4, IgE and IL-17A production and by increasing the tissue level of IFN-γ. 004 Programmed cell death1 (PD-1) regulates the effector function of autoimmune CD8 T cells and protects against immune-related disease N Okiyama and SI Katz Dermatology Branch, CCR, NCI, NIH, Bethesda, MD PD-1 is an inhibitory molecule expressed by activated T cells. Its ligands (PD-L1 and -L2) are expressed by many leukocytes and non-leukocytes. Recent clinical trials have shown that anti-PD-1 or anti-PD-L1 blocking antibodies enhance cancer immunity. To assess the role of PD-1 in CD8 T cell-mediated diseases, we used PD-1 knockout (KO)-OVA-specific T cell-receptor transgenic (Tg) CD8 T cells (OT-I cells) in a murine model of graft-versus-host disease (GvHD). Mice expressing membranebound ovalbumin in skin and mucosae (mOVA mice) develop a GvHD-like disease, manifested by skin/mucosal lesions and weight loss, after transfer of м5×10 5 OT-I cells. Recovery begins 14 days after adoptive cell transfer. We found that mOVA mice that received as few as 5×10 4 PD-1KO-OT-I cells developed GvHD with intense skin and mucosal lesions and with significant weight loss (-16.6%±2.7) by day 7, and mice required euthanasia by day 9. mOVA mice that received 5×10 4 wild-type OT-I cells did not develop lesions or weight loss (-1.1%±3.3, p<0.05; U test). FACS analysis showed that PD-1KO-OT-I cells accumulated in skin-draining lymph nodes and spleens (6.7% and 31.3%, respectively) of mOVA mice 7 days after cell transfer to a greater extent than wildtype OT-I cells (1.8% and 2.9%). Four days after cell transfer, >90% of OT-I cells, CD4 T cells and DCs expressed PD-L1, and 7 days after transfer 39.5% of CD4 T cells and 14.1% of DCs expressed PD-L2. Consistent with our prior studies, when mOVA×OT-I double Tg (dTg) mice received 1×10 6 OT-I cells they did not develop GvHD, whereas dTg mice that received 1×10 6 PD-1KO-OT-I cells developed disease with skin/mucosal lesions and weight loss (-15.3%±1.6, p<0.01; U test) at day 6. In aggregate, our data strongly suggest that the PD-1/PD-L1, -L2 system can influence the development and/or progression of CD8 T cell-mediated immune disease. Enhancement of PD-1 or PDL1/PDL2 expression by effector cells, accessory cells or target cells may attenuate CD8 T cellmediated diseases, including GvHD. 002 The possibility of having the same pathogenesis of mycosis fungoides, large-and small plaque parapsoriasis A Sidikov, D Zaslavsky, R Nasyrov and Z Zouli Dermatology and Venerology, Saint-Petersburg Pediatric Medical University, Saint-Petersburg, Russian Federation Background: Large plaque parapsoriasis (LPP) and Small plaque parapsoriasis are general diseases, which are related to cutaneous T-cell lymphoproliferative disorders, whose biological distinction from early Mycosis Fungoides (MF) is still not clearly defined. Objectives: Some authors recently have found the preponderance of immature dendritic cells (CD209/DC-SIGN) in MF and syndrome Sezary lesions, while in the normal skin these cells were absent. The authors supposed that it is probably important for the mediation of immunological tolerance against malignant T-cells. Therefore, the purpose of our study is to show the expression of CD209/DC-SIGN markers in order to investigate the role of these markers in LPP and SPP. Methods: Three patients with LPP and seven patients with SPP were included in the study. Skin biopsy were obtained from lesions well-circumscribed round or oval pink patches. Patients with LPP lesions have patches with size more than 8-10 cm and patients with SPP lesions have patches with size less than 5-6 cm in diameter. Immunohistochemistry was performed on the paraffin tissue sections for CD209/DC-SIGN monoclonal antibodies. Results: The study showed a significant infiltration of CD209/DC-SIGN in dermal infiltrate in both conditions. Limitations: The number of patients was small. Conclusions: Our study possibility demonstrates that LPP and SPP have the same pathogenetic mechanisms like MF and syndrome Sezary. The presence of immature dentritic cells (CD209/DC-SIGN) in dermal infiltrate probably play important role in the mediation of immunological tolerance against malignant T -cells. For the representative results of these pathogenetic mechanisms it needs a control group of patients with non-chronic dermatitis. Langerhans' cells (LCs) are the outermost sentinels of the immune system, with dual immunostimulatory and immunoregulatory roles. Following stimulation with self or foreign antigen, LCs disengage from neighbouring keratinocytes and migrate to draining lymph nodes. Integrins are bidirectional signalling molecules associated with various aspects of cellular physiology, migration and survival. They exist as heterodimers, with α and β subunits. LC migration in mice is contingent upon functional α6 and α4 integrins with presumed β1 integrin partner subunits. We have investigated the role of β1 integrin function in human LC mobilisation using an epidermal explant assay. Four 6mm punch biopsies were taken from sun-protected skin of 6 healthy subjects (age 18-30y) and incubated in ethylenediaminetetraacetic acid (EDTA) for 2h before the epidermis was mechanically removed using forceps. For each subject, 1 epidermal sheet was fixed in acetone immediately (for baseline counts) and the remaining 3 sheets cultured at 37C for 24h in RPMI medium alone or in the presence of 10ug/ml functional or non-functional rat anti-β1 integrin IgG2a monoclonal antibody. The sheets were stained with CD1a-fluorescein isothiocyanate (FITC) antibody before LC counts were performed using immunofluorescent microscopy. Mean LC counts were 1131 +/-SD 253 per mm2 at baseline with approximately 18% LCs migrating at 24h in the presence of either culture medium alone (mean LC count 933 +/-SD 270) or added non-functional anti-β1 integrin antibody (mean LC count 922 +/-SD 223). In the presence of functional anti-β1 integrin antibody, LC migration was significantly reduced (p<0.01; mean LC count 1085 +/-SD 229; mean migration 3.5%). These findings implicate functional β1 integrin-containing heterodimers in the migration of LC from the epidermis. Future investigations will utilise the explant model to further explore integrin subunit involvement in LC migration. CCL27, a chemokine constitutively expressed in the epidermis of adults, is a key chemo-attractant for CLA+ memory T cells. Recently, it has been reported that, in contrast to adult skin, prenatal skin harbors only few memory T cells. In this study we investigated whether this scarcity correlates with CCL27 levels during gestation in vivo and analyzed its expression in fetal and adult human primary keratinocyte (KC) as well as organotypic skin cultures in vitro. Immunofluorescence revealed no/low CCL27 expression in embryonic (9-14 weeks estimated gestational age (EGA)) and fetal (18-24 weeks EGA) human skin, respectively, as compared to the strong staining pattern observed in adult skin. In line with this in situ expression pattern, secreted CCL27 was present in supernatants of ex-vivo skin cultures derived from adult skin samples but was absent in supernatants of prenatal skin. Similarly, CCL27 was produced and secreted in vitro by adult primary human KC but not in fetal primary human KC. Stimulation with the TLR3 ligand poly (I:C) -a potent inducer of a variety of chemokines in KC -led to a strong induction of CCL27 secretion merely in adult but not in fetal KC. Given that a major difference between pre-and post-natal epidermis is the differentiation status of KC, we investigated the effect of KC-differentiation on CCL27 production and secretion in monolayer and organotypic skin cultures using adult KC. In both experimental settings, cell-differentiation strongly up-regulated CCL27 expression and secretion in KC. Together our findings suggest that CCL27 plays a major role for the influx of memory T cells during skin development. In addition, we demonstrated that epidermal CCL27 secretion is strongly dependent on KC differentiation. We have recently found that the neuropeptide CGRP enhances production of IL-6, a cytokine important for Th17 cell differentiation, by stimulated ECs and others have shown that NE also has this effect. Thus, we asked whether CGRP alters the outcome of LC antigen presentation via effects on bystander ECs. We used the transformed BALB/c EC line, bEnd.3, to examine this question. bEnd.3 cells (10 4 /well) were plated in round-bottom 96-well plates in medium containing 100 nM CGRP, 10 -5 M NE or medium alone. After 3 h, plates were washed x 4. Then, 10 4 LCs (obtained from BALB/c epidermis by magnetic antibody separation) and 3x10 5 T cells from DO11.10 mice (BALB/c background) were added per well followed by addition of a chicken ovalbumin fragment (cOVA 323-339 ) to 10 μM. DO11.10 mice express transgenes such that their T cells recognize cOVA 323-339 . Other wells were set-up without bEnd.3 cells. After 48 h of culture, cells were harvested and CD4 + T cells analyzed by FACS. In cultures containing CGRP-or NE-treated bEnd.3 cells, T cells expressing intracellular IL-17A were increased along with a decreased number of T cells expressing interferon gamma (IFNγ). In replicate cultures, T cells were isolated and RNA extracted for quantitative RT-PCR. Treatment of bEnd.3 cells with CGRP or NE resulted in enhanced mRNA expression for RORγt, IL-6 and IL-17A with decreased expression of IFNγ and T-bet. Supernatants from these cultures assayed for cytokine production by ELISA revealed that addition of CGRP-or NE-exposed bEnd.3 cells significantly enhanced IL-6 and IL-17A production while significantly inhibiting IFNy production. Preliminary experiments examining IL-6 and IL-17A production with primary murine dermal microvascular ECs substituted for bEnd.3 cells yielded a similar result. As vessels within the dermis and secondary lymphoid organs are associated with sensory and sympathetic nerves, these results suggest a novel mechanism of regulation of cutaneous immunity by the nervous system. Myeloid-derived suppressor cells (MDSC) comprise a heterogeneous population of cells (CD11b+, Gr-1+) that can be found in tumor-bearing hosts. We previously reported that MDSCs suppress the activity of T cells together with Tregs through B7H1-mediated pathways. To further investigate the suppressive function of B7H1 in melanoma, first we subcutaneously injected mice with 2 x 105 B16F10, administered several doses of B7H1Ab and then assessed the suppressive capacities of B7H1Ab in vivo. The administration of B7H1 Ab significantly suppressed the B16F10 melanoma growth in a dose-dependent manner. FACS analysis revealed that the blocking of B7H1 in vivo induced CD69 expression on CD4 and CD8 cells in the tumor-bearing host. To analyze the suppressive function of MDSC, we isolated CD11b+ cells and co-cultivated them with syngeneic CD4+ T cells and allogeneic BMDCs. Actually, splenic, B7H1 highly expressing CD11b+ cells suppress the proliferation of CD4+ T cells. Next, to develop B7H1 targeting immunotherapy, we set up therapeutic models for B16F10 melanoma using imiquimod (IQM) and dacarbazine (Dac). The administration of IQM with Dac significantly suppressed the B16F10 melanoma growth. Moreover, we investigated the mechanisms of the suppressive function of this immuno/chemotherapy, especially focusing on B7H1-expressing MDSC. Interestingly, IQM/Dac therapy induced the differentiation of IL-10 producing, B7H1 expressing MDSC into IFN-γ producing macrophages, which might be related to the suppression of melanoma growth. Our results suggest that splenic CD11b+ cells highly express B7H regulatory molecules, and IQM/ Dac therapy differentiates these MDSC into immunogenic macrophages. To characterize the inflammatory infiltrates of acne vulgaris lesions, and to confirm previous transcriptomic results indicating the involvement of Th17 cells in the pathogenic process of acne, lesional and non-lesional human skin biopsies from twelve patients with inflammatory acne vulgaris were analyzed. qRT-PCR and Luminex assays were performed for mRNA and protein analysis, respectively. In parallel, histology and immunohistochemistry were performed to document the morphology of the lesions and to detect IL17-positive T cells in the inflammatory infiltrates. At the mRNA level, the most representative cytokines secreted by Th17 cells, including IL17A, IL17F and IL26, were found to be up-regulated in acne lesions. Furthermore, the protein levels of cytokines characterizing Th17 cells, such as IL6, IL17A, IL17F, IL22, IL23A, CCL20 and TNF, were up-regulated in lesional skin versus non-lesional skin (p<0.05). Histological examination was consistent with the diagnosis of acne vulgaris, most lesional biopsies showing perifolliculitis/folliculitis up to ruptured follicle walls. Infiltrates were more important in lesional biopsies when compared to non-lesional areas (10/12 and 0/12 patients with a score of slight to marked, respectively). IL17 positive cells were found to be correlated with the presence of infiltrates. IL17 positive cells were mainly CD3 positive cells in lesional as well as non-lesional samples (87+/-14 % and 90% +/-11 %, respectively). Our results identify acne vulgaris as an inflammatory disorder mediated among other factors by a Th17 response. These findings indicate new possibilities to target the inflammatory response in acne vulgaris. Acne vulgaris is a common disease characterized by androgen dependence, follicular hyperkeratosis, increased sebum excretion, colonization with P. acnes and inflammatory events. The formation of microcomedone is preceded by mononuclear, mainly CD4 positive T-cell infiltrates and macrophages. We examined the biopsies obtained from early inflamed lesions and non-lesional skin of acne patients (n=20) and, as control, lesional and non-lesional skin of psoriasis patients (n=9) by RT-PCR and immunohistochemistry. RT-PCR showed significant similarities between cytokine profiles in lesions of acne and psoriasis. We found increased expression of Th17 cytokines: IL-17A increase was 22.7-fold (p< 0.001) in lesions of acne compared to the non-lesional skin and 20.1fold (p<0.001) in psoriasis in lesional compared to non-lesional skin. IL-23p19 increased 3.1-fold in acne and 9.2-fold in psoriasis, p<0.001 in both diseases. Also Th1 markers CXCR3, T-bet and INFgamma were significantly increased in acne and psoriasis compared to non-lesional skin. Foxp3 elevation was 2.5 fold in acne and 4.1 fold in psoriasis (p<0.001 in both) and also TGF-beta and IL-10 increased very significantly. IL-17 is known to be a potent inducer of antimicrobial peptides and chemotaxis of neutrophils. Pro-inflammatory cytokine IL-8, IL-1beta and TNF-alpha were significantly increased as well as the antimicrobial peptides S100A7, S100A9, LCN2, hBD2, hBD3 and hCAP18. Immunohistochemistry revealed IL-17A and Foxp3 positive cells. Naturally the localization of the positive cells was different in acne compared to psoriasis. This is the first study linking Th17 and Treg cells to early inflammatory events in acne lesions and shows similarities in cytokine profiles in acne and psoriasis. Contact dermatitis is an inflammatory skin condition resulting from cutaneous contact with materials. Dendritic cells (DCs)-derived reactive oxygen species (ROS) during antigen presentation were reported to play important roles in the pathogenesis of contact dermatitis. Previously, we have shown that allergen-induced ROS increase immune responses in XS106 DCs and human monocyte-derived DCs (MoDCs). However the roles of irritant-induced ROS in XS106 DCs are not fully characterized. Therefore, herein, we have evaluated the roles of ROS produced in XS106 DCs by irritant, benzalkonium chloride (BKC). ROS were produced by BKC in XS106 DCs and ROS production was increased in correlation to the incubation time. When pretreated with GSH, catalase and vitamin E, ROS productions were blocked. Apoptosis was increased in BKC-treated XS106 DCs in concentration dependent manner. However, antioxidants did not prevent apoptosis which implies that apoptosis by BKC is not related to ROS produced by BKC stimulation. Cell surface molecules, such as CD80, CD86 and MHC II, were expressed on XS106 DCs both before and after BKC treatment without significant differences. Cytokine production from BKC-treated XS106 DCs was checked by ELISA. IL-12 and IL-4 secretions were not increased in XS106 DCs by BKC.TNF-α was produced in XS106 DCs in correlation to the concentration of BKC. TNF-α secretion was blocked by GSH and vitamin E, but not by catalase. In summary, the role of BKC-induced ROS in XS106 DCs is different from TNBS-induced ROS. BKC-induced ROS in XS106 DCs do not have a role related to the immune response but probably only related to inflammation. In mice, epidermis is colonized by invariant γδ dendritic epithelial T cells and CD8 αβ T cells but human intraepidermal T cells remain largely uncharacterized. We find that T cells are as numerous as Langerhans cells in the epidermis of healthy human skin. In contrast to mice, all intraepidermal T cells (IET) were αβ, γδ T cells were not evident, and both CD4 and CD8 T cells were present, in a ratio of 3:1. 44% of IET CD4 cells expressed CD103, as compared to 13% in the dermis and central memory T cells were rare. IET contained both FOXP3 + Treg and effector T cells. IET had distinct cytokine profiles with significantly increased TNFα and IL-22 and decreased IL-4 production as compared to human CD4 dermal T cells (DT). IL-17 and IFNγ were elevated but not significantly higher in IET. In contrast to DT, IET responded poorly to mitogens, showed limited proliferative capacity and underwent apoptotic cell death, prevented by the caspase inhibitor Z-VAD-FMK, after removal from the epidermis. We infused allogeneic human CD103blood T cells into NSG mice grafted with human foreskin, which lacks resident T cells. Human T cells migrated specifically into the grafted human skin and T cells within the epidermis upregulated CD103 expression but those in the dermis did not (17% IET CD103 + vs. 1% DT). Stimulation in direct contact with keratinocytes, but not in transwells and not with fibroblasts, significantly upregulated CD103 expression on human blood T cells in vitro. CD103 + IET persisted in CTCL patients treated with alemtuzumab, which depletes recirculating but not sessile skin T cells, suggesting CD103 + IET do not recirculate. In summary, we find human epidermis contains a distinct population of nonrecirculating CD103 + intraepithelial lymphocytes that are functionally and phenotypically distinct from other skin T cells and may play a critical role in protecting the skin from infection. 070 Deciphering the role of Langerin+ Dermal DC in the immune response inducing by skin scarification (S.S.) with vaccinia virus (VACV) The murine Langerin Diphteria Toxin Receptor (Lang-DTR transgenic mice) allows us to dissect the relative roles of Langerhans cells (LC, late repopulators) and Langerin+ dermal DC (Ln+dDC, early repopulations) after administration of diphtheria toxin. Mice skin scarified (s.s.) with VACVova showed rapid proliferation of OT-1 cells in skin draining nodes, rapid distribution of OT-1 cells to skin by day 3, peaking at day 7, strong cytotoxicity to ova-expressing tumors (EG7) in vitro, and protection against tumor growth in vivo. Mice depleted only of LC were indistinguishable from normal mice in all these parameters. However, mice depleted of both LC and Ln+dDC showed delayed >4 day proliferation in draining nodes, only 20% of control numbers of skin OT-1 cells at day 7, and poor in vitro cytotoxicity. However, their ability to induce E and P selectin ligands on OT-1 cells was unimpaired. A third dermal population of DC exists, that are CD11c+ and Ln-; these were unaffected by our treatments. In tumor growth experiments, mice depleted of LC and Ln+dDC still showed significant delay in tumor growth (300mm3 at day 3 in normal mice, vs day 21 in LC and Ln+dDC deficient mice). We therefore conclude that Ln+dDC's, and LC play a non-dominant role in tumor immunity in this model, and that Ln-DC and lymph node resident DC play a pivotal role. The major role of Ln+dDC may be in protection against acute viral infection, while other Ln-DC's may play a more important role in tumor rejection. Purpose: The persistent expression of Merkel cell polyomavirus (MCPyV) oncoproteins in Merkel cell carcinoma (MCC) provides a unique opportunity to characterize immune evasion mechanisms in human cancer. We isolated MCC-specific T cells and determined their frequency, functional status and response to inhibitory receptor blockade. Experimental Design: Multi-parameter flow cytometry panels and HLA/peptide tetramers were used to identify and characterize T cells from tumors (n=7) and blood (n=18) of MCC patients and control subjects (n=10). PD-1 ligand (PD-L1) and CD8 expression within tumors were determined using mRNA profiling (n=35) and immunohistochemistry (n=13). Results: MCPyV-specific CD8 T cells were detected directly ex vivo from the blood of 7 of 11 (64%) patients with MCPyV-positive tumors. In contrast, 0 of 10 control subjects had detectable levels of these cells in their blood (p<0.01). MCPyV-specific T cells in serial blood specimens increased with MCC disease progression and decreased with effective therapy. MCC-specific CD8 T cells expressed higher levels of both PD-1 and Tim-3 inhibitory receptors compared to T cells specific to other human viruses (p<0.01). PD-L1 was present in 9 of 13 (69%) MCCs and its expression was correlated with CD8 lymphocyte infiltration. Antibodies targeting these inhibitory receptors augmented MCPyV-specific T cell cytokine production in response to the cognate antigen. Conclusion: MCC-specific T cells expand with tumor burden and show evidence of inhibition by PD-1 and Tim-3 exhaustion mechanisms. Reversal of these inhibitory pathways is therefore a promising therapeutic approach for this cancer. Acne vulgaris is the most common skin disorder affecting millions of people worldwide and inflammation resulting from immune responses targeting P. acnes plays a significant role in its pathogenesis. Our recent findings reveals that, P. acnes is a potent inducer of Th17 and Th1, but not Th2 responses in human PBMCs. P. acnes stimulated expression of genes known to directly signal Th17 responses including IL-17A, RORα, RORc, IL-17RA and IL-17RC. The subset of T cells identified to secrete IL-17 was primarily CD4+ and not CD8+ T cells. Supernatants from P. acnes-stimulated PBMCs were sufficient to promote the differentiation of naïve CD4+CD45RA T cells into Th17 cells. Furthermore, we found that the combination of IL-1β, IL-6 and TGF-β neutralizing antibodies completely inhibited IL-17 production. Importantly, we demonstrate that IL-17-expressing cells were present in skin biopsies from acne patients but not from normal donors suggesting that IL-17induced inflammation may have clinical relevance. Finally, we found that both all-trans retinoic acid (ATRA) and the biologically active form of vitamin D3 (1,25D3) inhibited P. acnes-induced Th17 differentiation. Together, our data suggest that IL-17 may play a role in acne pathogenesis and that both ATRA and 1,25D3 could be effective tools to modulate Th17-mediated diseases such as acne.
doi:10.1038/jid.2013.94 fatcat:5wkt7r5vzvadjn4w6zjj7ub3ai