RESUMO
Antigen capturing at the periphery is one of the earliest, crucial functions of antigen-presenting cells (APCs) to initiate immune responses. Langerhans cells (LCs), the epidermal APCs migrate to draining lymph nodes (DLNs) upon acquiring antigens. An arsenal of endocytic molecules is available to this end, including lectins and pathogen recognition receptors (PRRs). However, cutaneous LCs are poorly defined in the early neonatal period. We assessed endocytic molecules expression in situ: Mannose (CD206)-, Scavenger (SRA/CD204)-, Complement (CD2l, CDllb)-, and Fc-Receptors (CD16/32, CD23) as well as CD1d, CD14, CD205, Langerin (CD207), MHCII, and TLR4 in unperturbed epidermal LCs from both adult and early neonatal mice. As most of these markers were negative at birth (day 0), LC presence was revealed with the conspicuous, epidermal LC-restricted ADPase (and confirmed with CD45) staining detecting that they were as numerous as adult ones. Unexpectedly, most LCs at day 0 expressed CD14 and CD204 while very few were MHCII+ and TLR4+. In contrast, adult LCs lacked all these markers except Langerin, CD205, CD11b, MHCII and TLR4. Intriguingly, the CD204+ and CD14+ LCs predominant at day 0, apparently disappeared by day 4. Upon cutaneous FITC application, LCs were reduced in the skin and a CD204+MHCII+FITC+ population with high levels of CD86 subsequently appeared in DLNs, with a concomitant increased percentage of CD3+CD69+ T cells, strongly suggesting that neonatal LCs were able both to ferry the cutaneous antigen into DLNs and to activate neonatal T cells in vivo. Cell cycle analysis indicated that neonatal T cells in DLNs responded with proliferation. Our study reveals that epidermal LCs are present at birth, but their repertoire of endocytic molecules and PRRs differs to that of adult ones. We believe this to be the first description of CDl4, CD204 and TLR4 in neonatal epidermal LCs in situ. Newborns' LCs express molecules to detect antigens during early postnatal periods, are able to take up local antigens and to ferry them into DLNs conveying the information to responsive neonatal T cells.
Assuntos
Células de Langerhans/imunologia , Células de Langerhans/fisiologia , Receptores de Superfície Celular/metabolismo , Linfócitos T/metabolismo , Animais , Animais Recém-Nascidos , Movimento Celular , Proliferação de Células , Células Epidérmicas/metabolismo , Feminino , Linfonodos , Camundongos , Camundongos Endogâmicos BALB C , Gravidez , Pele/imunologia , Membro 7 da Superfamília de Receptores de Fatores de Necrose TumoralRESUMO
Trypanosoma cruzi is a protozoan parasite that infects at least 7 million persons in the world (OMS, 2019). In endemic areas, infection normally occurs by vectorial transmission; however, outside, it normally happens by blood and includes congenital transmission. The persistence of T. cruzi during infection suggests the presence of immune evasion mechanisms and the modulation of the anti-parasite response to a profile incapable of eradicating the parasite. Dendritic cells (DCs) are a heterogeneous population of antigen-presenting cells (APCs) that patrol tissues with a key role in mediating the interface between the innate and adaptive immune response. Previous results from our lab and other groups have demonstrated that T. cruzi modulates the functional properties of DCs, in vitro and in vivo. During vectorial transmission, metacyclic (m) trypomastigotes (Tps) eliminated along with the insect feces reach the mucous membranes or injured skin. When transmission occurs by the hematic route, the parasite stage involved in the infection is the circulating or blood (b) Tp. Here, we studied in vitro the effect of both infective mTp and bTp in two different populations of DCs, bone marrow-derived DCs (BMDCs) and XS106, a cell line derived from epidermal DCs. Results demonstrated that the interaction of both Tps imparts a different effect in the functionality of these two populations of DCs, suggesting that the stage of T. cruzi and DC maturation status could define the immune response from the beginning of the ingress of the parasite, conditioning the course of the infection.
Assuntos
Células Dendríticas/imunologia , Células de Langerhans/imunologia , Trypanosoma cruzi/fisiologia , Animais , Apresentação de Antígeno , Linhagem Celular , Proliferação de Células , Células Dendríticas/metabolismo , Células Dendríticas/parasitologia , Interleucina-10/metabolismo , Células de Langerhans/metabolismo , Células de Langerhans/parasitologia , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Linfócitos T/fisiologia , Trypanosoma cruzi/crescimento & desenvolvimento , Trypanosoma cruzi/patogenicidade , Fator de Necrose Tumoral alfa/metabolismoRESUMO
BACKGROUND: Anogenital warts are the leading sexually transmitted infection in patients seeking care at specialized clinics. They may display a vast array of forms, according to the interaction of the virus with the host's immunity. Cellular immunity is the epithelium's main form of defense against the virus, involving an active participation of the Langerhans cells and pro-inflammatory cytokines such as TNF-α. OBJECTIVE: To assess the epithelial immune response of anogenital warts in males, according to the number of lesions presented. METHODS: This is a prospective, cross-sectional study carried out at the dermatology outpatient clinic in a tertiary hospital. We included male patients over 18 years of age without comorbidities who had anogenital condylomata and no previous treatments.In order to evaluate the local epithelial immunity, the lesions were quantified, then removed and employed in CD1a immunohistochemistry assays for assessing the morphometry and morphology of Langerhans cells; TNF-α; reaction was used for determining cytokine positivity in the epithelium. RESULTS: 48 patients were included in the study. There was no statistically significant difference as to the number of Langerhans cells, in their morphology, or the presence of TNF-α. However, patients presenting with more Langerhans cells in the lesions had cells with a star-like and dendritic morphology, whereas in those with a lower cell count had cells with a rounded morphology and no dendrites (p<0.001). STUDY LIMITATIONS: Small number of patients analyzed. CONCLUSION: There was no difference in epithelial immunity between patients having few or many anogenital condyloma lesions as measured by the morphology and morphometry of Langerhans cells and TNF-α; positivity. Such an assessment employing immunity markers differing from the usual ones is expected to yield useful results.
Assuntos
Doenças do Ânus/imunologia , Condiloma Acuminado/imunologia , Doenças dos Genitais Masculinos/imunologia , Células de Langerhans/patologia , Fator de Necrose Tumoral alfa/análise , Doenças do Ânus/patologia , Condiloma Acuminado/patologia , Estudos Transversais , Células Dendríticas/imunologia , Células Dendríticas/patologia , Doenças dos Genitais Masculinos/patologia , Humanos , Imuno-Histoquímica , Células de Langerhans/imunologia , Masculino , Estudos Prospectivos , Valores de Referência , Fator de Necrose Tumoral alfa/imunologiaRESUMO
Abstract Background: Anogenital warts are the leading sexually transmitted infection in patients seeking care at specialized clinics. They may display a vast array of forms, according to the interaction of the virus with the host's immunity. Cellular immunity is the epithelium's main form of defense against the virus, involving an active participation of the Langerhans cells and pro-inflammatory cytokines such as TNF-α. Objective: To assess the epithelial immune response of anogenital warts in males, according to the number of lesions presented. Methods: This is a prospective, cross-sectional study carried out at the dermatology outpatient clinic in a tertiary hospital. We included male patients over 18 years of age without comorbidities who had anogenital condylomata and no previous treatments.In order to evaluate the local epithelial immunity, the lesions were quantified, then removed and employed in CD1a immunohistochemistry assays for assessing the morphometry and morphology of Langerhans cells; TNF-α; reaction was used for determining cytokine positivity in the epithelium. Results: 48 patients were included in the study. There was no statistically significant difference as to the number of Langerhans cells, in their morphology, or the presence of TNF-α. However, patients presenting with more Langerhans cells in the lesions had cells with a star-like and dendritic morphology, whereas in those with a lower cell count had cells with a rounded morphology and no dendrites (p < 0.001). Study limitations: Small number of patients analyzed. Conclusion: There was no difference in epithelial immunity between patients having few or many anogenital condyloma lesions as measured by the morphology and morphometry of Langerhans cells and TNF-α; positivity. Such an assessment employing immunity markers differing from the usual ones is expected to yield useful results.
Assuntos
Humanos , Masculino , Doenças do Ânus/imunologia , Condiloma Acuminado/imunologia , Células de Langerhans/patologia , Fator de Necrose Tumoral alfa/análise , Doenças dos Genitais Masculinos/imunologia , Doenças do Ânus/patologia , Valores de Referência , Células Dendríticas/imunologia , Células Dendríticas/patologia , Imuno-Histoquímica , Condiloma Acuminado/patologia , Células de Langerhans/imunologia , Estudos Transversais , Estudos Prospectivos , Fator de Necrose Tumoral alfa/imunologia , Doenças dos Genitais Masculinos/patologiaRESUMO
Dermatophytosis is a cutaneous mycosis caused by a plethora of keratinophilic fungi, but Trichophyton rubrum is the most common etiological agent. Despite its high prevalence worldwide, little is known about the host defense mechanisms in this infection, particularly the in situ immune response. Using an immunohistochemistry approach, we investigated the density of CD1a+, factor XIIIa+ and CD68+ cells in the skin of dermatophytosis patients. Langerhans cells (CD1a+ cells) were significantly decreased in the epidermis of patients, both in affected and unaffected areas. In the dermis, however, no differences in the density of macrophages (CD68+ cells) and dermal dendrocytes (factor XIIIa+ cells) were observed. These results suggest that the decreased number of Langerhans cells may be a risk factor for development of dermatophytosis.
Assuntos
Dermatomicoses/imunologia , Dermatomicoses/patologia , Imunidade Inata/imunologia , Células de Langerhans/imunologia , Células de Langerhans/patologia , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Tinha/imunologia , Tinha/patologia , Adulto JovemRESUMO
Rosacea is a chronic inflammatory condition with predominant facial involvement. Because of that, many patients sense that rosacea affects quality of life. The etiology of rosacea remains unknown. Recent studies have suggested that aberrant innate immunity is central to this disease. The aim of this study was to examine the presence of Langerhans cells, plasmacytoid dentritic cells (PDC), the expression of Toll-like receptors (TLR) and inducible oxide nitric synthase (iNOS) in skin of patients with rosacea, to highlight the participation of innate immunity in its pathogenesis. 28 biopsy specimens were taken from patients with clinical and histopathological findings of rosacea. Immunohistochemical demonstration of Langerhans cells (anti-CD1a antibody), PDC (anti-CD 123 antibody), TLR2, TLR4 and iNOS was performed in skin samples and compared with normal skin controls. The expression of Langerhans cells was lower in rosacea group than in control group. PDC were found in skin samples of rosacea as isolated cells and forming small clusters. Expression of TLR2, TLR4 and iNOS was higher in rosacea samples than in normal skin controls. This research demonstrates early and late stage components of innate immunity in specimens of rosacea ratifying the existence of an altered innate immunity in its pathogenesis.
Assuntos
Imunidade Inata , Óxido Nítrico Sintase Tipo II/metabolismo , Rosácea/imunologia , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Adulto , Idoso , Biópsia , Estudos de Casos e Controles , Células Dendríticas/imunologia , Feminino , Humanos , Células de Langerhans/imunologia , Masculino , Pessoa de Meia-Idade , Óxido Nítrico Sintase Tipo II/imunologia , Qualidade de Vida , Rosácea/patologia , Pele/citologia , Pele/imunologia , Pele/patologia , Receptor 2 Toll-Like/imunologia , Receptor 4 Toll-Like/imunologiaRESUMO
DNA vaccination is an attractive approach to elicit tumor-specific cytotoxic CD8+ T lymphocytes (CTL), which can mediate protective immunity against tumors. To initiate CTL responses, antigen-encoding plasmids employed for DNA vaccination need to activate dendritic cells (DC) through the stimulation of DNA-sensing innate immune receptors that converge in the activation of the master transcription factor NF-κB. To this end, NF-κB repressor IκBα needs to be degraded, allowing NF-κB to translocate to the nucleus and transcribe proinflammatory target genes, as well as its repressor IκBα. Therefore, NF-κB activation is self-limited by de novo synthesis of IκBa, which sequesters NF-κB in the cytosol. Hence, we tested whether co-delivering a shRNA-based adjuvant able to silence IκBα expression would further promote DNA-induced NFκB activation, DC activation and tumor-protective CTL responses induced by DNA vaccination in a preclinical model. First, an IκBα-targeting shRNA plasmid (shIκBα) was shown to reduce IκBα expression and promote NFκB-driven transcription in vitro, as well as up-regulate inflammatory target genes in vivo. Then, we showed that intradermal DNA electroporation induced the migration of skin migratory dendritic cells to draining lymph nodes and maturation of dermal dendritic cells (dDC). Interestingly, shIκBα further promoted the migration of mature skin migratory dendritic cells, in particular dDC, which are specialized in antigen cross-presentation and activation of CD8+ T cells. Consistently, mice vaccinated with a plasmid encoding the melanoma-associated antigen tyrosinase-related protein 2 (TRP2) in combination with shIκBα enhanced TRP2-specific CTL responses and reduced the number of lung melanoma foci in mice challenged with intravenous injection of B16F10 cells. Moreover, therapeutic vaccination with pTRP2 and shIκBα delayed the growth of B16F10 melanoma subcutaneous tumors. Our data suggest that adjuvants promoting NF-κB activation represent an attractive strategy to boost DC activation and promote the generation of tumor-protective CTL responses elicited by DNA vaccines.
Assuntos
Vacinas Anticâncer/imunologia , Células de Langerhans/imunologia , Linfonodos/imunologia , Inibidor de NF-kappaB alfa/antagonistas & inibidores , RNA Interferente Pequeno/metabolismo , Linfócitos T Citotóxicos/imunologia , Vacinas de DNA/imunologia , Adjuvantes Imunológicos/metabolismo , Animais , Vacinas Anticâncer/administração & dosagem , Movimento Celular , Modelos Animais de Doenças , Células de Langerhans/fisiologia , Pulmão/patologia , Melanoma/patologia , Melanoma/terapia , Camundongos Endogâmicos C57BL , Resultado do Tratamento , Vacinação , Vacinas de DNA/administração & dosagemRESUMO
American cutaneous leishmaniasis (ACL) is a chronic infectious disease caused by different protozoan species of Leishmania, and it is endemic in both tropical and subtropical countries. Using immunohistochemistry, we investigate the density of CD68+, lysozyme+, CD1a+, factor XIIIa+, CD4+, CD8+, CD56+, interferon (IFN)-γ+, and inducible NO synthase (iNOS+) cells. These cells were analyzed from 22 biopsy samples obtained from the lesions of ACL patients, whose infection was caused by Leishmania (Viannia) spp. Histopathological analysis showed dense mononuclear inflammatory infiltration in the dermis, which was composed of lymphocytes, macrophages, plasma cells, and discrete tissue parasitism. Granulomatous reactions were also present in the majority of cases. The density of the activated macrophages was higher than that of inactivated macrophages in the lesions. The density of Langerhans cells (CD1a+) was lower than that of dermal dendrocytes (factor XIIIa+). The density of CD8+ T lymphocytes was higher than that of CD4+ T lymphocytes. The cellular density of these immunological markers in relation to the species of Leishmania demonstrated that L. (Viannia) sp. lesions had higher IFN-γ expression than that Leishmania (Viania) braziliensis lesions. The evaluation of these markers, according to disease progression, did not reveal any significant differences. L. (Viannia) sp. infection leads to a favorable immune response in the host, as predominantly represented by lysozyme+, factor XIIIa+, CD8+ T cells, and the expression of (IFN)-γ+ at the lesion site.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Células de Langerhans/imunologia , Leishmania braziliensis/imunologia , Leishmania/imunologia , Leishmaniose Cutânea/imunologia , Macrófagos/imunologia , Adolescente , Adulto , Antígenos CD1 , Brasil , Contagem de Linfócito CD4 , Linfócitos T CD8-Positivos/citologia , Derme/parasitologia , Derme/patologia , Progressão da Doença , Fator XIIIa/metabolismo , Feminino , Humanos , Interferon gama/metabolismo , Células de Langerhans/citologia , Leishmaniose Cutânea/parasitologia , Ativação de Macrófagos/imunologia , Masculino , Pessoa de Meia-Idade , Muramidase/metabolismo , Adulto JovemRESUMO
The clinical course of infection with Mycobacterium leprae varies widely and depends on the pattern of the host immune response. Dendritic cells play an important role in the activation of the innate and adaptive immune system and seem to be essential for the development of the disease. To analyze the presence of epidermal dendritic cells (CD1a and CD207), plasmacytoid dendritic cells (CD123) and dermal dendrocytes (factor XIIIa) in lesion fragments of leprosy patients, skin samples from 30 patients were studied. These samples were submitted to immunohistochemistry against CD1a, CD207, FXIIIa, and CD123. The results showed a larger number of Langerhans cells, detected with the CD1a or CD207 marker, dermal dendrocytes and plasmacytoid dendritic cells in patients with the tuberculoid form. A positive correlation was observed between the Langerhans cell markers CD1a and CD207 in both the tuberculoid and lepromatous forms, and between Langerhans cells and dermal dendrocytes in samples with the tuberculoid form. The present results indicate the existence of a larger number of dendritic cells in patients at the resistant pole of the disease (tuberculoid) and suggest that the different dendritic cells studied play a role, favoring an efficient immune response against infection with M. leprae.
Assuntos
Antígenos CD1/imunologia , Antígenos CD/imunologia , Células Dendríticas/imunologia , Fator XIIIa/imunologia , Subunidade alfa de Receptor de Interleucina-3/imunologia , Células de Langerhans/imunologia , Lectinas Tipo C/imunologia , Hanseníase/imunologia , Lectinas de Ligação a Manose/imunologia , Pele/imunologia , Derme/citologia , Derme/imunologia , Humanos , Hanseníase/microbiologia , Hanseníase/patologia , Mycobacterium leprae/fisiologia , Pele/patologiaRESUMO
BACKGROUND: Actinic cheilitis (AC) is a potentially malignant lesion diagnosed in the lip of patients chronically exposed to the sun that may give rise to a fully invasive lower lip squamous cell carcinoma (LLSCC). It is known that ultraviolet radiation causes dendritic cells (DCs) depletion in the epidermis, but the role of this cellular population in lip cancer progression remains uncertain. Therefore, this study investigated the distribution of DCs in normal, dysplastic and neoplastic tissues of the lower lip. METHODS: Thirteen cases of lower lip mucocele, 42 of ACs and 21 of LLSCC were retrieved and original diagnoses confirmed by two oral pathologists, who further classified ACs as low- and high-risk lesions. Immunoreactions against CD1a and CD83 identified immature and mature DCs, respectively. RESULTS: Immature CD1a+ Langerhans cells (LCs) were significantly decreased in LLSCC when compared to morphologically normal (P < 0.009) and dysplastic epitheliums (P < 0.003), whereas mature CD83+ LCs were significantly decreased in LLSCC when compared to normal epithelium (P = 0.038). There was no significant difference between low- and high-risk ACs regarding CD1a+ and CD83+ LCs (P > 0.05), but ACs demonstrated a lower concentration of CD1a+ LCs than normal epithelium (P < 0.009). There was no significant difference in the distribution of CD1a+ and CD83+ interstitial dendritic cells (IDCs) in the connective tissue among the studied groups (P > 0.05). CONCLUSION: These results suggest that depletion of epithelial LCs, but not IDCs in the connective tissue, would represent an important step for lip cancer development.