RESUMO
The tetraspanin CD151 is a marker of aggressive cell proliferation and invasiveness for a variety of cancer types. Given reports of CD151 expression on T cells, we explored whether CD151 would mark T cells in a hyperactivated state. Consistent with the idea that CD151 could mark a phenotypically distinct T cell subset, it was not uniformly expressed on T cells. CD151 expression frequency was a function of the T cell lineage (CD8 > CD4) and a function of the memory differentiation state (naive T cells < central memory T cells < effector memory T cells < T effector memory RA+ cells). CD151 and CD57, a senescence marker, defined the same CD28- T cell populations. However, CD151 also marked a substantial CD28+ T cell population that was not marked by CD57. Kinome array analysis demonstrated that CD28+CD151+ T cells form a subpopulation with a distinct molecular baseline and activation phenotype. Network analysis of these data revealed that cell cycle control and cell death were the most altered process motifs in CD28+CD151+ T cells. We demonstrate that CD151 in T cells is not a passive marker, but actively changed the cell cycle control and cell death process motifs of T cells. Consistent with these data, long-term T cell culture experiments in the presence of only IL-2 demonstrated that independent of their CD28 expression status, CD151+ T cells, but not CD151- T cells, would exhibit an Ag-independent, hyperresponsive proliferation phenotype. Not unlike its reported function as a tumor aggressiveness marker, CD151 in humans thus marks and enables hyperproliferative T cells.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Proliferação de Células , Regulação da Expressão Gênica/imunologia , Tetraspanina 24/imunologia , Antígenos CD28/genética , Antígenos CD28/imunologia , Antígenos CD57/genética , Antígenos CD57/imunologia , Senescência Celular/genética , Senescência Celular/imunologia , Regulação da Expressão Gênica/genética , Humanos , Tetraspanina 24/genéticaRESUMO
In animal models, IL-12 and IL-23 participate in the development of malignant neoplasms of keratinocytes. However, the role of these cytokines in pigmented lesion development and their progression to melanoma has received little attention. IL-12p35, IL-23p19, and IL-12/IL-23p40 knockout mice on a C3H/HeN background, subjected to a melanomagenesis protocol, demonstrated profound differences in susceptibility to nevus initiation, transformation, tumorigenicity, and metastatic potential. IL-23 was found to be essential for melanocyte homeostasis, whereas IL-12 supported nevus development. A direct action of IL-23 on primary melanocytes, shown to be IL-23R+, demonstrated that DNA repair of damaged melanocytes requires IL-23. Furthermore, IL-23 modulated the cutaneous microenvironment by limiting regulatory T cells and IFN-γ and inhibiting IL-10 production. Neutralizing Ab to IFN-γ, but not IL-17, inhibited nevus development (p < 0.01).
Assuntos
Reparo do DNA/imunologia , Interleucina-23/imunologia , Melanoma Experimental/imunologia , Neoplasias Cutâneas/imunologia , Linfócitos T Reguladores/imunologia , Animais , Modelos Animais de Doenças , Citometria de Fluxo , Interleucina-12 , Melanócitos/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Nus , Reação em Cadeia da Polimerase , Subpopulações de Linfócitos T/imunologiaRESUMO
Prevention of tumors induced by environmental carcinogens has not been achieved. Skin tumors produced by polyaromatic hydrocarbons, such as 7,12-dimethylbenz(a)anthracene (DMBA), often harbor an H-ras point mutation, suggesting that it is a poor target for early immunosurveillance. The application of pyrosequencing and allele-specific PCR techniques established that mutations in the genome and expression of the Mut H-ras gene could be detected as early as 1 d after DMBA application. Further, DMBA sensitization raised Mut H-ras epitope-specific CTLs capable of eliminating Mut H-ras(+) preneoplastic skin cells, demonstrating that immunosurveillance is normally induced but may be ineffective owing to insufficient effector pool size and/or immunosuppression. To test whether selective pre-expansion of CD8 T cells with specificity for the single Mut H-ras epitope was sufficient for tumor prevention, MHC class I epitope-focused lentivector-infected dendritic cell- and DNA-based vaccines were designed to bias toward CTL rather than regulatory T cell induction. Mut H-ras, but not wild-type H-ras, epitope-focused vaccination generated specific CTLs and inhibited DMBA-induced tumor initiation, growth, and progression in preventative and therapeutic settings. Transferred Mut H-ras-specific effectors induced rapid tumor regression, overcoming established tumor suppression in tumor-bearing mice. These studies support further evaluation of oncogenic mutations for their potential to act as early tumor-specific, immunogenic epitopes in expanding relevant immunosurveillance effectors to block tumor formation, rather than treating established tumors.
Assuntos
Vacinas Anticâncer/uso terapêutico , Genes ras/genética , Mutação Puntual/genética , Neoplasias Cutâneas/prevenção & controle , 9,10-Dimetil-1,2-benzantraceno/toxicidade , Animais , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Vacinas Anticâncer/administração & dosagem , Carcinógenos/toxicidade , Citocinas/imunologia , Citocinas/metabolismo , Análise Mutacional de DNA , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Epitopos/genética , Epitopos/imunologia , Feminino , Genes ras/imunologia , Células HEK293 , Humanos , Imunoterapia Adotiva/métodos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos , Mutação Puntual/efeitos dos fármacos , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/genética , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/metabolismo , Resultado do Tratamento , Carga Tumoral/imunologiaRESUMO
Heat shock proteins (HSPs) are constitutively expressed in murine skin. HSP27 is present in the epidermis, and HSP70 can be found in both the epidermis and dermis. The purpose of this study was to investigate the role of these proteins in cutaneous chemical carcinogenesis and to determine whether their effects on cell-mediated immune function were a contributing factor. In vivo inhibition of HSP27 and HSP70 produced a reduction in the T cell-mediated immune response to 7,12-dimethylbenz(a)anthracene (DMBA) and benzo(a)pyrene in C3H/HeN mice and resulted in a state of Ag-specific tolerance. When mice were pretreated with anti-HSP27 and anti-HSP70 Abs in vivo prior to subjecting them to a standard two-stage DMBA/12-O-tetradecanoylphorbol-13-acetate cutaneous carcinogenesis protocol, the percentage of mice with tumors was much greater (p < 0.05) in anti-HSP27- and HSP70-pretreated animals compared with mice pretreated with control Ab. Similar results were obtained when the data were evaluated as the cumulative number of tumors per group. Mice pretreated with HSP27 and HSP70 Abs developed more H-ras mutations and fewer DMBA-specific cytotoxic T lymphocytes. These findings indicate that in mice HSP27 and HSP70 play a key role in the induction of cell-mediated immunity to carcinogenic polyaromatic hydrocarbons. Bolstering the immune response to carcinogenic polyaromatic hydrocarbons may be an effective method for prevention of the tumors that they produce.
Assuntos
Carcinogênese/imunologia , Proteínas de Choque Térmico HSP27/imunologia , Proteínas de Choque Térmico HSP70/imunologia , Tolerância Imunológica/imunologia , Neoplasias Cutâneas/imunologia , 9,10-Dimetil-1,2-benzantraceno/imunologia , 9,10-Dimetil-1,2-benzantraceno/toxicidade , Animais , Carcinógenos/toxicidade , Modelos Animais de Doenças , Feminino , Camundongos , Camundongos Endogâmicos C3H , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/metabolismoRESUMO
Acquired melanocytic nevi are commonly found in sun exposed and unexposed human skin, but the potential for their transformation into invasive melanoma is not clear. Therefore, a mouse model of nevus initiation and progression was developed in C3H/HeN mice using a modified chemical carcinogenesis protocol. Nevi develop due to DNA damage initiated by dimethylbenz(a) anthracene (DMBA) followed by chronic promotion with 12-O-tetradecanoyl-phorbol-13-acetate (TPA). Dysplastic pigmented skin lesions appeared in 7-9 wk with 100% penetrance. Nests of melanocytic cells appeared in a subset of skin draining lymph nodes (dLN) by 25 wk, but not in age matched controls. Immunohistochemistry, real-time PCR, and flow cytometric analyses confirmed their melanocytic origin. Transformed cells were present in a subset of nevi and dLNs, which exhibited anchorage-independent growth, tumor development, and metastasis in nude mice. Approximately 50% of the cell lines contained H-Ras mutations and lost tumor suppressor p16(Ink4a) expression. While most studies of melanoma focus on tumor progression in transgenic mouse models where the mutations are present from birth, our model permits investigation of acquired mutations at the earliest stages of nevus initiation and promotion of nevus cell transformation. This robust nevus/melanoma model may prove useful for identifying genetic loci associated with nevus formation, novel oncogenic pathways, tumor targets for immune-prevention, screening therapeutics, and elucidating mechanisms of immune surveillance and immune evasion.
Assuntos
Modelos Animais de Doenças , Melanoma/genética , Nevo Pigmentado/induzido quimicamente , Nevo Pigmentado/genética , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/genética , 9,10-Dimetil-1,2-benzantraceno , Animais , Linhagem Celular Tumoral , Separação Celular , Inibidor p16 de Quinase Dependente de Ciclina , Progressão da Doença , Melanoma/patologia , Camundongos , Camundongos Nus , Mutação , Proteínas de Neoplasias/genética , Nevo Pigmentado/patologia , Neoplasias Cutâneas/patologia , Acetato de Tetradecanoilforbol , Proteínas ras/genéticaRESUMO
The ability of dendritic cells (DCs) to orchestrate innate and adaptive immune responses has been exploited to develop potent anti-cancer immunotherapies. Recent clinical trials exploring the efficacy of ex vivo modified autologous DC-based vaccines have reported some promising results. However, in vitro generation of autologous DCs for clinical administration, their loading with tumor associated antigens (TAAs) and their activation, is laborious and expensive, and, as a result of inter-individual variability in the personalized vaccines, remains poorly standardized. An attractive alternative approach is to load resident DCs in vivo by targeted delivery of TAAs, using viral vectors and activating them simultaneously. To this end, we have constructed genetically-modified adenoviral (Ad) vectors and bispecific adaptor molecules to retarget Ad vectors encoding TAAs to the CD40 receptor on DCs. Pre-clinical human and murine studies conducted so far have clearly demonstrated the suitability of a 'two-component' (i.e. Ad and adaptor molecule) configuration for targeted modification of DCs in vivo for cancer immunotherapy. This review summarizes recent progress in the development of CD40-targeted Ad-based cancer vaccines and highlights pre-clinical issues in the clinical translation of this approach.
Assuntos
Antígenos CD40 , Vacinas Anticâncer/genética , Células Dendríticas/imunologia , Neoplasias/terapia , Adenoviridae/genética , Animais , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/imunologia , Antígenos CD40/genética , Antígenos CD40/imunologia , Vacinas Anticâncer/imunologia , Técnicas de Transferência de Genes , Vetores Genéticos , Humanos , Imunoterapia , Ativação Linfocitária , CamundongosRESUMO
The pathogenic connection of type I IFN and its role in regulating the migration response of Ag delivery by B cells into lymphoid follicles in an autoimmune condition has not been well-identified. Here, we show that there was a significantly larger population of marginal zone precursor (MZ-P) B cells, defined as being IgM(hi)CD1d(hi)CD21(hi)CD23(hi) in the spleens of autoimmune BXD2 mice compared with B6 mice. MZ-P B cells were highly proliferative compared with marginal zone (MZ) and follicular (FO) B cells. The intrafollicular accumulation of MZ-P B cells in proximity to germinal centers (GCs) in BXD2 mice facilitated rapid Ag delivery to the GC area, whereas Ag-carrying MZ B cells, residing predominantly in the periphery, had a lower ability to carry Ag into the GCs. IFN-alpha, generated by plasmacytoid dendritic cells, induced the expression of CD69 and suppressed the sphingosine-1-phosphate-induced chemotactic response, promoting FO-oriented Ag transport by MZ-P B cells. Knockout of type I IFN receptor in BXD2 (BXD2-Ifnalphar(-/-)) mice substantially diffused the intrafollicular MZ-P B cell conglomeration and shifted their location to the FO-MZ border near the marginal sinus, making Ag delivery to the FO interior less efficient. The development of spontaneous GCs was decreased in BXD2-Ifnalphar(-/-) mice. Together, our results suggest that the MZ-P B cells are major Ag-delivery B cells and that the FO entry of these B cells is highly regulated by type I IFN-producing plasmacytoid dendritic cells in the marginal sinus in the spleens of autoimmune BXD2 mice.
Assuntos
Autoimunidade/imunologia , Subpopulações de Linfócitos B/imunologia , Interferon Tipo I/imunologia , Baço/imunologia , Células-Tronco/imunologia , Animais , Apresentação de Antígeno/imunologia , Autoantígenos/imunologia , Subpopulações de Linfócitos B/citologia , Linfócitos B/citologia , Linfócitos B/imunologia , Movimento Celular/imunologia , Células Dendríticas Foliculares/citologia , Células Dendríticas Foliculares/imunologia , Feminino , Citometria de Fluxo , Imunofluorescência , Centro Germinativo/citologia , Centro Germinativo/imunologia , Ativação Linfocitária/imunologia , Camundongos , Camundongos Knockout , Microscopia Confocal , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Baço/citologia , Células-Tronco/citologiaRESUMO
Organ transplant recipients (OTRs) develop multiple aggressive and metastatic non-melanoma skin cancers (NMSCs). Yet, the underlying mechanism remains elusive. Employing a variety of immune-compromised murine models, immunoblotting, immunohistochemical and immunofluorescence techniques, we show that human squamous xenograft tumors in nude mice grow faster and become significantly larger in size following treatment with the immunosuppressive drug, cyclosporine A (CsA). Re-injected tumor cells isolated from CsA-treated xenografts continued to form larger tumors in nude mice than those from vehicle-controls and retained the CsA-signatures of calcineurin signaling inhibition. Similar results were obtained when these tumors were grown in SCID-beige mice or in immuno-competent mice inoculated with syngeinic tumor cells. Consistently, tumors in the CsA group manifested enhanced cellular proliferation and decreased apoptosis. Tumors in CsA-treated animals also showed an augmented epithelial-mesenchymal transition (EMT) characterized by an increased expression of fibronectin, α-SMA, vimentin, N-cadherin, MMP-9/-2, snail and twist with a concomitant decrease in E-cadherin. CsA-treated xenograft tumors manifested increased TGFß1 expression and TGFß-dependent signaling characterized by increased nuclear p-Smad 2/3. Our data demonstrate that CsA alters the phenotype of skin SCCs to an invasive and aggressive tumor-type by enhancing expression of proteins regulating EMT acting through the TGFß1 signaling pathway providing at least one unique mechanism by which multiple aggressive and metastatic NMSCs develop in OTRs.
Assuntos
Carcinoma de Células Escamosas/patologia , Ciclosporina/farmacologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Transdução de Sinais , Neoplasias Cutâneas/patologia , Fator de Crescimento Transformador beta/metabolismo , Animais , Apoptose/efeitos dos fármacos , Western Blotting , Carcinoma de Células Escamosas/metabolismo , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Feminino , Imunofluorescência , Humanos , Marcação In Situ das Extremidades Cortadas , Camundongos , Camundongos Nus , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias Cutâneas/metabolismo , Transplante HeterólogoRESUMO
Melanocytic nevi are benign proliferations of pigment cells that can occasionally develop into melanomas. There is a significant correlation between increased nevus numbers and melanoma development. Our previous reports revealed that 7,12-dimethylbenz(a)anthracene (DMBA) and 12-O-tetradecanoyl-phorbol-13-acetate (TPA) induced dysplastic nevi in C3H/HeN mice, with a potential to transform into melanomas. To understand the immune mechanisms behind this transformation, we applied increasing DMBA doses followed by TPA to the skin of C3H/HeN mice. We observed that increased doses of DMBA correlated well with increased numbers of nevi. The increased DMBA dose induced diminished immune responses and promoted the expansion of regulatory T cells (Treg) that resulted in increased IL10 and reduced IFNγ levels. Mice with increased nevus numbers had loss of p16 expression. These mice had increased migration of melanocytic cells to lymph nodes (LN) and a greater percent of LNs produced immortalized melanocytic cell lines. DMBA-induced immunosuppression was lost in CD4-knockout (KO) mice. Lymphocytes in the CD4KO mice produced less IL10 than CD8KO mice. Furthermore, CD4KO mice had significantly reduced nevus numbers and size compared with wild-type and CD8KO mice. These results suggest that Tregs play a vital role in the incidence of nevi and their progression to melanoma.Prevention Relevance: There has been little progress in developing novel strategies for preventing premalignant dysplastic nevi from becoming melanomas. In this study in mice, regulatory-T cells enhanced progression of benign nevi to malignant melanomas; and by inhibiting their activity, melanomas could be retarded. The findings identify new possibilities for melanoma prevention in high risk individuals.
Assuntos
Melanoma Experimental/imunologia , Nevo Pigmentado/imunologia , Neoplasias Cutâneas/imunologia , Linfócitos T Reguladores/imunologia , 9,10-Dimetil-1,2-benzantraceno/administração & dosagem , 9,10-Dimetil-1,2-benzantraceno/toxicidade , Animais , Antígenos CD4/genética , Antígenos CD8/genética , Feminino , Humanos , Tolerância Imunológica/efeitos dos fármacos , Masculino , Melanoma Experimental/induzido quimicamente , Melanoma Experimental/patologia , Camundongos , Camundongos Knockout , Nevo Pigmentado/induzido quimicamente , Nevo Pigmentado/patologia , Pele/efeitos dos fármacos , Pele/imunologia , Pele/patologia , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/patologia , Acetato de Tetradecanoilforbol/administração & dosagem , Acetato de Tetradecanoilforbol/toxicidadeRESUMO
Apoptosis plays an important role in eliminating UV-damaged keratinocytes, but its role in UV-induced immune suppression is not clear. Langerhans cells (LCs) may function as inducers of immune suppression. We have shown that LCs derived from mice deficient in the proapoptotic Bid (BH3-interacting death domain protein) gene (Bid KO) resist apoptosis and induce amplified immune responses. In this report, we examined responses in Bid KO mice to UVB exposure. Acute UV exposure led Bid KO mice to develop fewer apoptotic cells and retain a greater fraction of LCs in the epidermal layer of skin in comparison to wild-type mice. Bid KO mice were also markedly resistant to local and systemic UV tolerance induction to hapten sensitization and contact hypersensitivity responses. Elicitation responses and inflammation at skin sensitization sites in UV-treated Bid KO mice were equal to or greater than nonsuppressed control responses. In Bid KO mice, LCs accumulated in lymph nodes to greater numbers, demonstrated longer lifespans, and contained fewer DNA-damaged cells. These studies provide evidence that Bid activation is a critical upstream mediator in UV-induced keratinocyte and LC apoptosis and that its absence abrogates UV-induced immune tolerance.
Assuntos
Apoptose/efeitos da radiação , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/fisiologia , Terapia de Imunossupressão , Pele/citologia , Raios Ultravioleta , Animais , Proteínas Reguladoras de Apoptose , Tolerância Imunológica/efeitos da radiação , Queratinócitos/citologia , Células de Langerhans/citologia , Camundongos , Camundongos Knockout , Pele/efeitos da radiaçãoRESUMO
Solar UVR is highly mutagenic but is only partially absorbed by the outer stratum corneum of the epidermis. UVR can penetrate into the deeper layers of the epidermis, depending on melanin content, where it induces DNA damage and apoptosis in epidermal cells, including those in the germinative basal layer. The cellular decision to initiate either cellular repair or undergo apoptosis has evolved to balance the acute need to maintain skin barrier function with the long-term risk of retaining precancerous cells. Langerhans cells (LCs) are positioned suprabasally, where they may sense UV damage directly, or indirectly through recognition of apoptotic vesicles and soluble mediators derived from surrounding keratinocytes. Apoptotic vesicles will contain UV-induced altered proteins that may be presented to the immune system as foreign. The observation that UVR induces immune tolerance to skin-associated antigens suggests that this photodamage response has evolved to preserve the skin barrier by protecting it from autoimmune attack. LC involvement in this process is not clear and controversial. We will highlight some basic concepts of photobiology and review recent advances pertaining to UV-induced DNA damage, apoptosis regulation, novel immunomodulatory mechanisms and the role of LCs in generating antigen-specific regulatory T cells.
Assuntos
Apoptose , Dano ao DNA , Tolerância Imunológica/efeitos da radiação , Ilhotas Pancreáticas/imunologia , Raios Ultravioleta , Animais , Humanos , Ilhotas Pancreáticas/patologiaRESUMO
Trauma-hemorrhage produces immunodepression in males but not in proestrus females and this difference is due to the presence of high estrogen in proestrus females. Although skin is the largest immunological organ of the body and is considered the first line of defense, no study to-date has examined whether trauma-hemorrhage has any effects on keratinocytes which are the major epidermal cell type (>90%) of skin. We therefore examined whether epidermal keratinocytes inflammatory response and the signal transduction pathways involved in the inflammatory response are altered following trauma-hemorrhage. C3H/HeN mice were subjected to trauma-hemorrhage and 2h thereafter; keratinocytes were harvested and stimulated with LPS for 24h (5 microg/ml). Inflammatory mediators, Toll-like receptor (TLR) and myeloid differentiation adaptor protein (MyD88) expression, and the activation of mitogen-activated protein kinase (MAPK) were determined. Trauma-hemorrhage increased the production of IL-6, IL-10, IL-12 and TNF-alpha enhanced the expression of TLR4, MyD88 as well as the activation of MAPK proteins (p38, ERK and JNK) in epidermal keratinocytes. However, administration of a single dose of 17beta-estradiol following trauma-hemorrhage prevented the increase in these inflammatory parameters under those conditions. These findings suggest that 17beta-estradiol normalizes epidermal keratinocytes inflammatory responses following trauma-hemorrhage by preventing the upregulation of TLR4-mediated MAPK activation.
Assuntos
Epiderme/lesões , Epiderme/patologia , Estradiol/fisiologia , Hemorragia/metabolismo , Queratinócitos/metabolismo , Sistema de Sinalização das MAP Quinases/fisiologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Receptor 4 Toll-Like/metabolismo , Animais , Células Cultivadas , Epiderme/enzimologia , Epiderme/metabolismo , Hemorragia/enzimologia , Hemorragia/fisiopatologia , Inflamação/enzimologia , Inflamação/metabolismo , Inflamação/fisiopatologia , Queratinócitos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C3HRESUMO
Sunscreens applied to the skin are retained primarily in the stratum corneum, where they adsorb and act as a barrier preventing UV penetration to deeper layers. Photophysical properties of sunscreens have traditionally been studied either in solvents, which are very different from skin, or in skin or complex artificial skin systems, which are difficult to handle. The purpose of this study was to determine whether polystyrene nanospheres could serve as an improvement over solvents for evaluation of the photophysical properties of sunscreens without the presence of autofluorescence from and interactions with specific skin biomolecules. We used HaCat cells and excised skin for this comparative study with nanospheres. Fluorescence spectral properties of common hydrophobic sunscreens octyl salicylate, padimate O (2-ethylhexyl-4-dimethylaminobenzoate) and octyl methoxycinnamate adsorbed to 220 nm polystyrene spheres are similar to those of sunscreens adsorbed to HaCat cells and excised skin. Specifically, similarity in the emission peaks and their approximate positions, excitation peak positions and a measurable reduction in scattering upon sunscreen addition suggest that polystyrene nanospheres constitute a useful system to evaluate the photophysical properties of topical sunscreens and may serve as a model system for high-throughput evaluation of potential sunscreens. An unexpected result of this comparative study was the observation of an increase in a specific skin component emission caused by addition of padimate O.
Assuntos
Fenômenos Fisiológicos da Pele , Protetores Solares/química , Protetores Solares/farmacocinética , Adsorção , Linhagem Celular , Humanos , Nanotecnologia , Espectrometria de Fluorescência , Espectrofotometria , Espectrofotometria UltravioletaRESUMO
Skin pigmentation is due to the accumulation of two types of melanin granules in the keratinocytes. Besides being the most potent blocker of ultraviolet radiation, the role of melanin in photoprotection is complex. This is because one type of melanin called eumelanin is UV absorbent, whereas the other, pheomelanin, is photounstable and may even promote carcinogenesis. Skin hyperpigmentation may be caused by stress or exposure to sunlight, which stimulates the release of α-melanocyte stimulating hormone (α-MSH) from damaged keratinocytes. Melanocortin 1 receptor (MC1R) is a key signaling molecule on melanocytes that responds to α-MSH by inducing expression of enzymes responsible for eumelanin synthesis. Persons with red hair have mutations in the MC1R causing its inactivation; this leads to a paucity of eumelanin production and makes red-heads more susceptible to skin cancer. Apart from its effects on melanin production, the α-MSH/MC1R signaling is also a potent anti-inflammatory pathway and has been shown to promote antimelanoma immunity. This review will focus on the role of MC1R in terms of its regulation of melanogenesis and influence on the immune system with respect to skin cancer susceptibility.
Assuntos
Melaninas/fisiologia , Receptor Tipo 1 de Melanocortina/fisiologia , Neoplasias Cutâneas/fisiopatologia , Humanos , Neoplasias Induzidas por Radiação/fisiopatologiaRESUMO
The ability to deliver antigens and immunomodulators specifically to Langerhans cells (LCs) in the skin could impact vaccine development. However, cell-specific targeting of therapeutic molecules remains a challenge in biomedicine. Using phage display technologies, we have developed a protocol that identifies peptides that mediate uptake into target cell types. Employing this approach, we have isolated a 20-mer peptide that mediates specific uptake by immunopotent LCs. The peptide is functional outside the context of the phage and is able to deliver a nanoparticle to LCs in vitro. Although selected on cells in vitro, the peptide is able to direct antigens and genes to LCs in vivo. Liposomes bearing the LC targeting peptide are able to deliver a transcriptionally active gene to LCs in a mouse model. Furthermore, we demonstrate that a low-dose injection into mice of phage bearing the LC-targeting peptide yields faster and higher immune responses against phage-associated antigens than control-phage injections.
Assuntos
Células de Langerhans/imunologia , Peptídeos/administração & dosagem , Sequência de Aminoácidos , Animais , Linhagem Celular , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Peptídeos/química , Peptídeos/imunologia , Pele/imunologiaRESUMO
Dendritic cells (DCs) are "professional" antigen-presenting cells (APCs) that are uniquely capable of activating and instructing a naive immune system to mount a specific cellular and humoral response. Recognition of this crucial function makes the development of technologies for DC-based immuno-therapies a priority for the treatment of a wide variety of diseases. The most immediate impact of this emerging technology will be in the treatment of cancer and the development of third generation vaccines to protect against viral and intracellular pathogens. In addition to elicitation of immune responses, DCs also function to maintain tolerance to "self." Once the biological basis for this important function is understood, future applications of DC-based immuotherapies may be developed to ameliorate autoimmune diseases or enhance acceptance of transplanted organs. The feasibility of "engineering" the function of DCs has been realized by recent advances in ex vivo methodologies that allow selective DC propagation, antigen loading, and genetic modification in vitro for subsequent therapeutic transfer into the host. Ultimately, the ability to genetically modify these cells will allow us to design DC-mediated interventions that will direct predictable control of either immune activation or tolerance in vivo.
Assuntos
Adenoviridae/genética , Células Dendríticas/metabolismo , Técnicas de Transferência de Genes , Vetores Genéticos , Animais , Apoptose , Citometria de Fluxo , Humanos , Ativação Linfocitária , CamundongosRESUMO
BACKGROUND: Osteopontin (OPN) is a matricellular glycoprotein that is markedly expressed in cutaneous squamous cell carcinomas (cSCCs) and in actinic keratoses implicating its role in photocarcinogenesis. OBJECTIVE: To determine whether OPN facilitates the development of cSCC and its function. METHODS: cSCCs development was compared between wild-type (WT) and OPN-null mice subjected to UVB irradiation for 43 weeks. UVB-induced OPN expression was determined by Western blot, immunoprecipitation, ELISA, and semi-quantitative RT-PCR. Epidermal layer and TUNEL analyses assessed if OPN mediates UVB-induced epidermal hyperplasia or suppresses UVB-induced apoptosis of basal keratinocytes, respectively. In vitro experiments determined whether OPN enhances cell survival of UVB-induced apoptosis and its potential mechanisms. Immunohistochemical analyses of epidermis assessed the expression of CD44 and focal adhesion kinase (FAK), molecules that mediate OPN survival function. RESULTS: Compared to female WT mice, OPN-null mice did not develop cSCCs. UVB irradiation stimulated OPN protein expression in the dorsal skin by 11h and remains high at 24-48h. OPN did not mediate UVB-induced epidermal hyperplasia; instead, it protected basal keratinocytes from undergoing apoptosis upon UVB exposure. Likewise, the addition of OPN suppressed UVB-induced OPN-null cSCC cell apoptosis, the activation of caspase-9 activity, and increased phosphorylation of FAK at Y397. Furthermore, the expression of CD44 and FAK in WT mice epidermis was greater than that of OPN-null mice prior to and during early acute UVB exposure. CONCLUSION: These data support the hypothesis that chronic UVB-induced OPN expression protects the survival of initiated basal keratinocytes and, consequently, facilitates cSCC develop.
Assuntos
Carcinoma de Células Escamosas/metabolismo , Transformação Celular Neoplásica/metabolismo , Epiderme/efeitos da radiação , Neoplasias Induzidas por Radiação/metabolismo , Osteopontina/metabolismo , Neoplasias Cutâneas/metabolismo , Raios Ultravioleta/efeitos adversos , Animais , Apoptose/efeitos da radiação , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/prevenção & controle , Linhagem Celular , Sobrevivência Celular/efeitos da radiação , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Modelos Animais de Doenças , Epiderme/metabolismo , Epiderme/patologia , Feminino , Quinase 1 de Adesão Focal/metabolismo , Regulação da Expressão Gênica , Receptores de Hialuronatos/metabolismo , Hiperplasia , Queratinócitos/metabolismo , Queratinócitos/patologia , Queratinócitos/efeitos da radiação , Camundongos da Linhagem 129 , Camundongos Knockout , Neoplasias Induzidas por Radiação/genética , Neoplasias Induzidas por Radiação/patologia , Neoplasias Induzidas por Radiação/prevenção & controle , Osteopontina/deficiência , Osteopontina/genética , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/prevenção & controle , Fatores de TempoRESUMO
Although keratinocytes are relatively resistant to ultraviolet radiation (UVR) induced damage, repeated UVR exposure result in accumulated DNA mutations that can lead to epidermal malignancies. Keratinocytes play a central role in elaborating innate responses that lead to inflammation and influence the generation of adaptive immune responses in skin. Apart from the minor cellular constituents of the epidermis, specifically Langerhans cells and melanocytes, keratinocytes are the major source of cytokines. UVR exposure stimulates keratinocytes to secrete abundant pro-inflammatory IL-1-family proteins, IL-1α, IL-1ß, IL-18, and IL-33. Normal skin contains only low levels of inactive precursor forms of IL-1ß and IL-18, which require caspase 1-mediated proteolysis for their maturation and secretion. However, caspase-1 activation is not constitutive, but dependents on the UV-induced formation of an active inflammasome complex. IL-1 family cytokines can induce a secondary cascade of mediators and cytokines from keratinocytes and other cells resulting in wide range of innate processes including infiltration of inflammatory leukocytes, induction of immunosuppression, DNA repair or apoptosis. Thus, the ability of keratinocytes to produce a wide repertoire of proinflammatory cytokines can influence the immune response locally as well as systematically, and alter the host response to photodamaged cells. We will highlight differential roles played by each IL-1 family molecule generated by UV-damaged keratinocytes, and reveal their complementary influences in modulating acute inflammatory and immunological events that follow cutaneous UV exposure.
Assuntos
Epiderme/efeitos da radiação , Inflamassomos/efeitos da radiação , Interleucina-18/imunologia , Interleucina-1alfa/imunologia , Interleucina-1beta/imunologia , Interleucinas/imunologia , Queratinócitos/efeitos da radiação , Apoptose/imunologia , Apoptose/efeitos da radiação , DNA/metabolismo , Reparo do DNA/imunologia , Reparo do DNA/efeitos da radiação , Células Epidérmicas , Epiderme/imunologia , Humanos , Imunidade Inata/efeitos da radiação , Inflamassomos/imunologia , Inflamação/imunologia , Interleucina-18/metabolismo , Interleucina-1alfa/metabolismo , Interleucina-1beta/metabolismo , Interleucina-33 , Interleucinas/metabolismo , Queratinócitos/citologia , Transdução de Sinais/imunologia , Transdução de Sinais/efeitos da radiação , Raios Ultravioleta/efeitos adversosRESUMO
Rhabdomyosarcoma (RMS) is a common soft-tissue sarcoma of childhood in need of more effective therapeutic options. The expression of p53 in RMS is heterogeneous such that some tumors are wild-type whereas others are p53 mutant. The small molecule CP-31398 modulates both the wild-type and the mutant p53 proteins. Here, we show that CP-31398 blocks the growth of RMS cells that have either wild-type or mutant p53 status. In wild-type A204 cells, CP-31398 increased the expression of p53 and its downstream transcriptional targets, p21 and mdm2; enhanced the expression of apoptosis-related proteins; and reduced proliferation biomarkers. Flow profiling of CP-31398-treated cells indicated an enhancement in sub-G(0) and G(1) populations. CP-31398 inhibited proliferation in a manner associated with co-induction of SOX9 and p21. Apoptosis induced by CP-31398 occurred with translocation of p53 to mitochondria, leading to altered mitochondrial membrane potential, cytochrome c release, and reactive oxygen species release. In vivo, CP-31398 decreased the growth of tumor xenografts composed of wild-type or mutant p53 tumor cells, increasing tumor-free host survival. Our findings indicate that the ability of CP-31398 to modulate wild-type and mutant p53 results in the inhibition of RMS growth and invasiveness.
Assuntos
Apoptose/efeitos dos fármacos , Pirimidinas/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Rabdomiossarcoma/tratamento farmacológico , Proteína Supressora de Tumor p53/metabolismo , Animais , Apoptose/fisiologia , Processos de Crescimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Ciclosporina/farmacologia , Citocromos c/metabolismo , Interações Medicamentosas , Feminino , Fase G1/efeitos dos fármacos , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mutação , Pirimidinas/antagonistas & inibidores , Rabdomiossarcoma/genética , Rabdomiossarcoma/metabolismo , Rabdomiossarcoma/patologia , Fatores de Transcrição SOX9/biossíntese , Ativação Transcricional/efeitos dos fármacos , Proteína Supressora de Tumor p53/biossíntese , Proteína Supressora de Tumor p53/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Adenoviral (Ad) vectors have been used for a variety of vaccine applications including cancer and infectious diseases. Traditionally, Ad-based vaccines are designed to express antigens through transgene expression of a given antigen. However, in some cases these conventional Ad-based vaccines have had sub-optimal clinical results. These sub-optimal results are attributed in part to pre-existing Ad serotype 5 (Ad5) immunity. In order to circumvent the need for antigen expression via transgene incorporation, the "antigen capsid-incorporation" strategy has been developed and used for Ad-based vaccine development in the context of a few diseases. This strategy embodies the incorporation of antigenic peptides within the capsid structure of viral vectors. The major capsid protein hexon has been utilized for these capsid incorporation strategies due to hexon's natural role in the generation of anti-Ad immune response and its numerical representation within the Ad virion. Using this strategy, we have developed the means to incorporate heterologous peptide epitopes specifically within the major surface-exposed domains of the Ad capsid protein hexon. Our study herein focuses on generation of multivalent vaccine vectors presenting HIV antigens within the Ad capsid protein hexon, as well as expressing an HIV antigen as a transgene. These novel vectors utilize HVR2 as an incorporation site for a twenty-four amino acid region of the HIV membrane proximal ectodomain region (MPER), derived from HIV glycoprotein gp41 (gp41). Our study herein illustrates that our multivalent anti-HIV vectors elicit a cellular anti-HIV response. Furthermore, vaccinations with these vectors, which present HIV antigens at HVR2, elicit a HIV epitope-specific humoral immune response.