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1.
Front Immunol ; 15: 1200461, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39206204

RESUMEN

Dendritic cells (DCs) are known as unique professional antigen (Ag)-presenting cells (APCs) to prime naïve T cells for the initiation of adaptive immunity. While DCs are believed to play a pivotal role in generating anti-tumor T-cell responses, the importance of DCs in the protection from the progression of tumors remains elusive. Here, we show how the constitutive deficiency of CD11chi DCs influences the progression of tumors with the use of binary transgenic mice with constitutive loss of CD11chi DCs. Constitutive loss of CD11chi DCs not only enhances the progression of tumors but also reduces the responses of Ag-specific T cells. Furthermore, the congenital deficiency of CD11chi DCs generates the immunosuppressive tumor microenvironment (TME) that correlates with the marked accumulation of myeloid-derived suppressor cells (MDSCs) and the prominent productions of immunosuppressive mediators. Thus, our findings suggest that CD11chi DCs are crucial for generating anti-tumor T-cell responses and immunogenic TME to suppress the development of tumors.


Asunto(s)
Células Dendríticas , Ratones Transgénicos , Microambiente Tumoral , Animales , Células Dendríticas/inmunología , Microambiente Tumoral/inmunología , Ratones , Linfocitos T/inmunología , Células Supresoras de Origen Mieloide/inmunología , Células Supresoras de Origen Mieloide/metabolismo , Ratones Endogámicos C57BL , Antígeno CD11c/metabolismo , Neoplasias/inmunología , Línea Celular Tumoral
2.
Cancer Immunol Res ; 11(9): 1266-1279, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37432112

RESUMEN

Clec4A4 is a C-type lectin receptor (CLR) exclusively expressed on murine conventional dendritic cells (cDC) to regulate their activation status. However, the functional role of murine Clec4A4 (mClec4A4) in antitumor immunity remains unclear. Here, we show that mClec4A4 serves as a negative immune checkpoint regulator to impair antitumor immune responses. Deficiency of mClec4A4 lead to a reduction in tumor development, accompanied by enhanced antitumor immune responses and amelioration of the immunosuppressive tumor microenvironment (TME) mediated through the enforced activation of cDCs in tumor-bearing mice. Furthermore, antagonistic mAb to human CLEC4A (hCLEC4A), which is the functional orthologue of mClec4A4, exerted protection against established tumors without any apparent signs of immune-related adverse events in hCLEC4A-transgenic mice. Thus, our findings highlight the critical role of mClec4A4 expressed on cDCs as a negative immune checkpoint molecule in the control of tumor progression and provide support for hCLEC4A as a potential target for immune checkpoint blockade in tumor immunotherapy.

3.
Cell Rep ; 42(5): 112431, 2023 05 30.
Artículo en Inglés | MEDLINE | ID: mdl-37099426

RESUMEN

While dysbiosis in the gut is implicated in the impaired induction of oral tolerance generated in mesenteric lymph nodes (MesLNs), how dysbiosis affects this process remains unclear. Here, we describe that antibiotic-driven gut dysbiosis causes the dysfunction of CD11c+CD103+ conventional dendritic cells (cDCs) in MesLNs, preventing the establishment of oral tolerance. Deficiency of CD11c+CD103+ cDCs abrogates the generation of regulatory T cells in MesLNs to establish oral tolerance. Antibiotic treatment triggers the intestinal dysbiosis linked to the impaired generation of colony-stimulating factor 2 (Csf2)-producing group 3 innate lymphoid cells (ILC3s) for regulating the tolerogenesis of CD11c+CD103+ cDCs and the reduced expression of tumor necrosis factor (TNF)-like ligand 1A (TL1A) on CD11c+CD103+ cDCs for generating Csf2-producing ILC3s. Thus, antibiotic-driven intestinal dysbiosis leads to the breakdown of crosstalk between CD11c+CD103+ cDCs and ILC3s for maintaining the tolerogenesis of CD11c+CD103+ cDCs in MesLNs, responsible for the failed establishment of oral tolerance.


Asunto(s)
Disbiosis , Inmunidad Innata , Humanos , Disbiosis/metabolismo , Linfocitos/metabolismo , Cadenas alfa de Integrinas/metabolismo , Células Dendríticas/metabolismo , Antibacterianos/metabolismo , Mucosa Intestinal/metabolismo
4.
Int J Pharm ; 613: 121376, 2022 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-34915143

RESUMEN

We have developed an aggregate of D-octaarginine immobilized at multiple points on a co-polymer of N-vinylacetamide and acrylic acid. Previous studies revealed that immunoglobulin G and A were induced when mice were inoculated with influenza virus antigens under coadministration with the D-octaarginine-immobilized polymers as a mucosal vaccine adjuvant. Infection experiments demonstrated that mice vaccinated with a mixture of inactivated influenza viruses and the polymers were protected from infection with mouse-adapted infectious viruses. In the present study, we investigated the mechanism on antigen delivery under mucosal vaccination using the polymers. Two-hour retention of fluorescein-labeled ovalbumin (F-OVA) on the nasal mucosa was observed when applied with the polymers; nevertheless F-OVA was eliminated less than 10 min under polymer-free conditions. F-OVA mixed with the polymers was vigorously taken up into murine dendritic cells. Electrophoresis and dynamic light scattering analysis indicated that OVA interacted with the polymers. The uptake of F-OVA was hardly ever inhibited by the addition of an excess amount of intact OVA. The results suggested that viral antigens were accumulated on the mucosa and delivered into dendritic cells under basolateral membranes via dendrites extending to the mucosal surface and/or subsequent to their permeation through epithelial cells, when they were coadministered with D-octaarginine-immobilized polymers.


Asunto(s)
Péptidos de Penetración Celular , Adyuvantes de Vacunas , Animales , Ratones , Mucosa Nasal , Polímeros , Vacunación
5.
Front Immunol ; 12: 712676, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34394115

RESUMEN

Atopic dermatitis (AD) is a common pruritic inflammatory skin disease characterized by impaired epidermal barrier function and dysregulation of Thelper-2 (TH2)-biased immune responses. While the lineage of conventional dendritic cells (cDCs) are implicated to play decisive roles in T-cell immune responses, their requirement for the development of AD remains elusive. Here, we describe the impact of the constitutive loss of cDCs on the progression of AD-like inflammation by using binary transgenic (Tg) mice that constitutively lacked CD11chi cDCs. Unexpectedly, the congenital deficiency of cDCs not only exacerbates the pathogenesis of AD-like inflammation but also elicits immune abnormalities with the increased composition and function of granulocytes and group 2 innate lymphoid cells (ILC2) as well as B cells possibly mediated through the breakdown of the Fms-related tyrosine kinase 3 ligand (Flt3L)-mediated homeostatic feedback loop. Furthermore, the constitutive loss of cDCs accelerates skin colonization of Staphylococcus aureus (S. aureus), that associated with disease flare. Thus, cDCs maintains immune homeostasis to prevent the occurrence of immune abnormalities to maintain the functional skin barrier for mitigating AD flare.


Asunto(s)
Células Dendríticas/patología , Dermatitis Atópica/congénito , Inmunidad Adaptativa , Animales , Antígenos CD11/análisis , Calcitriol/análogos & derivados , Calcitriol/uso terapéutico , Recuento de Células , Citocinas/inmunología , Células Dendríticas/química , Células Dendríticas/inmunología , Dermatitis Atópica/inmunología , Dermatitis Atópica/patología , Fármacos Dermatológicos/uso terapéutico , Progresión de la Enfermedad , Susceptibilidad a Enfermedades , Eccema/inmunología , Eccema/patología , Retroalimentación Fisiológica , Homeostasis/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Organismos Libres de Patógenos Específicos , Infecciones Cutáneas Estafilocócicas/etiología , Staphylococcus aureus/patogenicidad , Células Th2/inmunología
6.
J Vet Med Sci ; 83(1): 134-141, 2021 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-33177289

RESUMEN

Interleukin 2 (IL-2) is a pleotropic cytokine and well-known as a T cell growth factor in immunology. It is now known to exert both immunostimulatory and immunosuppressive effects, optimizing immunological microenvironments for effector and regulatory T cell responses. The immunomodulatory role of IL-2 is critical for deciding whether or not T cell responses against specific antigens result in protection. We have established a mammalian cell line (HEK-293) stably expressing bovine IL-2 (boIL-2) (designated as HEK-293/boIL-2), using the piggyBac transposon system. The concentration of recombinant bovine IL-2 (rboIL-2) in the culture supernatant of HEK-293/boIL-2 reached 100 ng/ml on day 7 and showed similar proliferative activity to recombinant human IL-2 (rhuIL-2) for bovine peripheral mononuclear blood cells. Although rhuIL-2 has been often used to activate bovine T cells, our results indicate that characteristics of the T cell activation through rboIL-2 and huIL-2 appear slightly but significantly different. Interestingly, the rboIL-2/anti-boIL-2 monoclonal antibody (C5) (rboIL-2/C5) complex strongly induced proliferation of bovine NKp46+cells, natural killer (NK) cells, in vitro. This indicates that the rboIL-2/C5 complex could function as an IL-2 agonist specifically to increase the NK cell population, which in turn could enhance the activity of NK cells leading to protective immunity.


Asunto(s)
Interleucina-2 , Activación de Linfocitos , Animales , Bovinos , Citocinas , Células HEK293 , Humanos , Interleucina-2/genética , Proteínas Recombinantes/genética , Linfocitos T
7.
Commun Biol ; 3(1): 742, 2020 12 07.
Artículo en Inglés | MEDLINE | ID: mdl-33288832

RESUMEN

While sublingual immunotherapy (SLIT) is known as an allergen-specific treatment for type-1 allergies, how it controls allergic pathogenesis remains unclear. Here, we show the prerequisite role of conventional dendritic cells in submandibular lymph nodes (ManLNs) in the effectiveness of SLIT for the treatment of allergic disorders in mice. Deficiency of conventional dendritic cells or CD4+Foxp3+ regulatory T (Treg) cells abrogates the protective effect of SLIT against allergic disorders. Furthermore, sublingual antigenic application primarily induces antigen-specific CD4+Foxp3+ Treg cells in draining ManLNs, in which it is severely impaired in the absence of cDCs. In ManLNs, migratory CD11b+ cDCs are superior to other conventional dendritic cell subsets for the generation of antigen-specific CD4+Foxp3+ Treg cells, which is reflected by their dominancy in the tolerogenic features to favor this program. Thus, ManLNs are privileged sites in triggering mucosal tolerance mediating protect effect of SLIT on allergic disorders that requires a tolerogenesis of migratory CD11b+ conventional dendritic cells.


Asunto(s)
Células Dendríticas/fisiología , Hipersensibilidad/terapia , Inmunoterapia/métodos , Ganglios Linfáticos/citología , Ovalbúmina/inmunología , Animales , Especificidad de Anticuerpos , Antígenos CD4/metabolismo , Factores de Transcripción Forkhead/metabolismo , Inmunidad Celular , Inmunización , Inmunoglobulinas/metabolismo , Ratones , Ovalbúmina/toxicidad , Linfocitos T Reguladores/fisiología
8.
Sci Rep ; 10(1): 16375, 2020 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-32989237

RESUMEN

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

9.
Sci Rep ; 10(1): 8371, 2020 05 20.
Artículo en Inglés | MEDLINE | ID: mdl-32433498

RESUMEN

The integrin αE known as CD103 binds integrin ß7 to form the complete heterodimeric integrin molecule αEß7. CD103 is mainly expressed by lymphocytes within epithelial tissues of intestine, lung, and skin as well as subsets of mucosal and dermal conventional dendritic cells (cDCs). CD103 has been originally implicated in the attachment of lymphocytes to epithelium in the gut and skin through the interaction with E-cadherin expressed on intestinal epithelial cells, keratinocytes, and Langerhans cells (LCs). However, an impact of CD103 on the cutaneous immune responses and the development of inflammatory skin diseases remains elusive. Here, we report that CD103 regulates the development of psoriasiform dermatitis through the control of the function of cDCs. Deficiency in CD103 exacerbates psoriasiform dermatitis, accompanied by excessive epidermal hyperplasia and infiltration of inflammatory leukocytes. Furthermore, deficiency in CD103 not only accelerates the production of proinflammatory cytokines in psoriatic lesions but also promotes the generation of lymphocytes producing interleukin (IL)-17 in the skin-draining peripheral lymph nodes (PLNs). Under the deficiency in CD103, cDCs localized in PLNs enhance cytokine production following activation. Thus, our findings reveal a pivotal role for CD103 in the control of the function of cDCs to regulate cutaneous inflammation in psoriasiform dermatitis.


Asunto(s)
Antígenos CD/metabolismo , Dermatitis/metabolismo , Cadenas alfa de Integrinas/metabolismo , Psoriasis/metabolismo , Animales , Antígenos CD/genética , Autoinmunidad/genética , Autoinmunidad/fisiología , Diferenciación Celular/genética , Diferenciación Celular/fisiología , Dermatitis/genética , Femenino , Citometría de Flujo , Inmunohistoquímica , Cadenas alfa de Integrinas/genética , Queratinocitos/metabolismo , Células de Langerhans/metabolismo , Masculino , Ratones Endogámicos C57BL , Psoriasis/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
10.
Int Immunol ; 32(10): 673-682, 2020 09 30.
Artículo en Inglés | MEDLINE | ID: mdl-32415968

RESUMEN

C-type lectin receptors (CLRs), pattern recognition receptors (PRRs) with a characteristic carbohydrate recognition domain (CRD) in the extracellular portion, mediate crucial cellular functions upon recognition of glycosylated pathogens and self-glycoproteins. CLEC4A is the only classical CLR that possesses an intracellular immunoreceptor tyrosine-based inhibitory motif (ITIM), which possibly transduces negative signals. However, how CLEC4A exerts cellular inhibition remains unclear. Here, we report that the self-interaction of CLEC4A through the CRD is required for the ITIM-mediated suppressive function in conventional dendritic cells (cDCs). Human type 2 cDCs (cDC2) and monocytes display a higher expression of CLEC4A than cDC1 and plasmacytoid DCs (pDCs) as well as B cells. The extracellular portion of CLEC4A specifically binds to a murine cDC cell line expressing CLEC4A, while its extracellular portion lacking the N-glycosylation site or the EPS motif within the CRD reduces their association. Furthermore, the deletion of the EPS motif within the CRD or ITIM in CLEC4A almost completely impairs its suppressive effect on the activation of the murine cDC cell line, whereas the absence of the N-glycosylation site within the CRD exhibits partial inhibition on their activation. On the other hand, antagonistic monoclonal antibody (mAb) to CLEC4A, which inhibits the self-interaction of CLEC4A and its downstream signaling in murine transfectants, enhances the activation of monocytes and monocyte-derived immature DCs upon stimulation with a Toll-like receptor (TLR) ligand. Thus, our findings suggest a pivotal role of the CRD in self-interaction of CLEC4A to elicit the ITIM-mediated inhibitory signal for the control of the function of cDCs.


Asunto(s)
Carbohidratos/inmunología , Lectinas Tipo C/inmunología , Glicoproteínas de Membrana/inmunología , Receptores Inmunológicos/inmunología , Animales , Células Dendríticas/inmunología , Humanos , Motivo de Activación del Inmunorreceptor Basado en Tirosina/inmunología , Ratones , Ratones Endogámicos C57BL , Receptores de Reconocimiento de Patrones/inmunología
11.
Bioconjug Chem ; 30(12): 3028-3037, 2019 12 18.
Artículo en Inglés | MEDLINE | ID: mdl-31738536

RESUMEN

Mucosal vaccination, which secretion of immunoglobulin A (IgA) on the mucosa is accompanied by induction of immunoglobulin G (IgG) in the blood, is one of the most effective ways to circumvent influenza epidemics caused by incorrect prediction of epidemic viral strains or viral mutation. Secreted IgA is expected to prevent hosts from being infected with heterologous viruses because this antibody cross-reacts to strains other than those used for immunization. Our previous mouse experiments revealed that intranasal IgA with cross-reactivity was induced through nasal inoculation with inactivated whole viral particles of the H1N1 A/New Caledonia/20/99 IVR116 (NCL) strain in the presence of hyaluronic acid modified with tetraglycine-l-octaarginine. In the present study, heterologous influenza virus challenge was performed to validate a potential of the hyaluronic acid derivative as a mucosal adjuvant with cross-protective abilities. Serious weight loss was observed when mice were nasally inoculated with inactivated NCL viruses alone and subsequently exposed to mouse-adapted infectious viruses of the H1N1 A/Puerto Rico/8/34 (PR8) strain. The symptom associated with virus infection was hardly ever observed for mice inoculated with a mixture of the viral antigens and tetraglycine-l-octaarginine-linked hyaluronic acid, presumably due to high induction of IgG and IgA capable of cross-reacting to PR8 viruses. Less proliferation of PR8 viruses in those mice was also supported by an insignificant elevation of antibody levels through virus exposure. Our polysaccharide derivative enabled hosts to acquire adaptive immunity with cross-protective abilities against heterologous virus infection.


Asunto(s)
Adyuvantes Inmunológicos/química , Alphainfluenzavirus/inmunología , Reacciones Cruzadas/inmunología , Ácido Hialurónico/farmacología , Vacunas contra la Influenza/química , Gripe Humana/prevención & control , Adyuvantes Inmunológicos/farmacología , Administración Intranasal , Animales , Humanos , Ácido Hialurónico/química , Inmunoglobulina A/metabolismo , Inmunoglobulina G/metabolismo , Subtipo H1N1 del Virus de la Influenza A/inmunología , Ratones , Oligopéptidos/química
12.
Mol Pharm ; 16(3): 1105-1118, 2019 03 04.
Artículo en Inglés | MEDLINE | ID: mdl-30715891

RESUMEN

We have been investigating the potential use of polymers modified with cell-penetrating peptides as an adjuvant for mucosal vaccination and have already developed nondegradable poly( N-vinylacetamide- co-acrylic acid) (PNVA- co-AA) with which d-octaarginine, a typical cell-penetrating peptide, was grafted. Our previous murine infection experiments demonstrated that immunoglobulin G (IgG) and immunoglobulin A (IgA) were induced in systemic circulation and secreted on nasal mucosa, respectively, through 4-time nasal inoculations with a mixture of influenza viral antigens and d-octaarginine-linked PNVA- co-AA at 7-day intervals, and that immunized mice were perfectly protected from homologous virus infection. In the present study, we designed novel biodegradable polymers bearing cell-penetrating peptides from a perspective of clinical application. Hyaluronic acid whose glucuronic acid was modified with tetraglycine-l-octaarginine at a monosaccharide unit ratio of 30% was successfully developed. The hyaluronic acid derivative exhibited adjuvant activities identical to PNVA- co-AA bearing either d-octaarginine or tetraglycine-d-octaarginine under the above-mentioned inoculation schedule. We further found that there was no difference in humoral immunity between the 4-time inoculations at 7-day intervals and the 2-time inoculations at 28-day intervals. Intranasal IgA induced through the latter schedule with a smaller number of inoculations, which is clinically practical, exhibited cross-reactivity beyond the subtype of viral strains. In vitro toxicity studies demonstrated that the hyaluronic acid derivative was much less toxic than the corresponding PNVA- co-AA derivatives, and that both the polymers and their metabolites did not exhibit genotoxicity. Our results suggested that tetraglycine-l-octaarginine-linked hyaluronic acid would be a clinically valuable and safe adjuvant for mucosal vaccination.


Asunto(s)
Adyuvantes Inmunológicos/efectos adversos , Adyuvantes Farmacéuticos/efectos adversos , Ácido Hialurónico/análogos & derivados , Ácido Hialurónico/efectos adversos , Oligopéptidos/química , Vacunación/métodos , Administración Intranasal , Animales , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Péptidos de Penetración Celular/metabolismo , Reacciones Cruzadas/inmunología , Femenino , Humanos , Ácido Hialurónico/farmacología , Inmunidad Humoral , Inmunidad Mucosa , Inmunoglobulina A/inmunología , Inmunoglobulina A/metabolismo , Inmunoglobulina G/inmunología , Inmunoglobulina G/metabolismo , Ratones , Ratones Endogámicos BALB C , Mucosa Nasal/metabolismo
13.
Front Immunol ; 9: 1418, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29977242

RESUMEN

Disruption of skin homeostasis can lead to inflammatory cutaneous diseases resulting from the dysregulated interplay between epithelial keratinocytes and immune cells. Interleukin (IL)-22 signaling through membrane-bound IL-22 receptor 1 (IL-22R1) is crucial to maintain cutaneous epithelial integrity, and its malfunction mediates deleterious skin inflammation. While IL-22 binding protein (IL-22BP) binds IL-22 to suppress IL-22 signaling, how IL-22BP controls epithelial functionality to prevent skin inflammation remains unclear. Here, we describe the pivotal role of IL-22BP in mediating epithelial autoregulation of IL-22 signaling for the control of cutaneous pathogenesis. Unlike prominent expression of IL-22BP in dendritic cells in lymphoid tissues, epidermal keratinocytes predominantly expressed IL-22BP in the skin in the steady state, whereas its expression decreased during the development of psoriatic inflammation. Deficiency in IL-22BP aggravates psoriasiform dermatitis, accompanied by abnormal hyperproliferation of keratinocytes and excessive cutaneous inflammation as well as enhanced dermal infiltration of granulocytes and γδT cells. Furthermore, IL-22BP abrogates the functional alternations of keratinocytes upon stimulation with IL-22. On the other hand, treatment with IL-22BP alleviates the severity of cutaneous pathology and inflammation in psoriatic mice. Thus, the fine-tuning of IL-22 signaling through autocrine IL-22BP production in keratinocytes is instrumental in the maintenance of skin homeostasis.

14.
Chem Pharm Bull (Tokyo) ; 66(4): 375-381, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29607903

RESUMEN

We have been investigating the potential of oligoarginine-linked polymers as an adjuvant for mucosal vaccination that induces immunoglobulin G (IgG) in systemic circulation and immunoglobulin A (IgA) secreted on the mucosa. Our latest infection experiments demonstrated that mice immunized nasally with a mixture of inactivated influenza viruses and poly(N-vinylacetamide-co-acrylic acid) (PNVA-co-AA) modified with D-octaarginine were perfectly protected from homologous virus infection. On the contrary, virus infection was observed in mice immunized with the antigen alone. This difference was presumably due to insignificant induction of secreted IgA on the nasal mucosa in the latter mice. Since it was unclear whether the current induction level was sufficient for heterologous virus infection, we evaluated the effects of the chemical structures of oligoarginines conjugated to PNVA-co-AA on induction of intranasal IgA. The number and optical activity of the arginine residues and the degree of modification with oligoarginines in the polymer backbone were listed as a factor that would influence IgA induction. Mouse experiments revealed that maximization of the modification resulted in an increase in adjuvant activities of oligoarginine-linked polymers most effectively. Glycine segments inserted between oligoarginines and the polymer backbone were a prerequisite for the maximization. The highest IgA level was observed when antigens were coadministered with diglycine-D-octaarginine-linked PNVA-co-AA.


Asunto(s)
Adyuvantes Inmunológicos/química , Anticuerpos/inmunología , Arginina/química , Materiales Biocompatibles/química , Membrana Mucosa/inmunología , Cavidad Nasal/inmunología , Polímeros/química , Animales , Anticuerpos/química , Arginina/análogos & derivados , Femenino , Ratones , Ratones Endogámicos BALB C , Estructura Molecular , Membrana Mucosa/química
15.
J Allergy Clin Immunol ; 141(6): 2156-2167.e9, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29477579

RESUMEN

BACKGROUND: Exposure to dietary constituents through the mucosal surface of the gastrointestinal tract generates oral tolerance that prevents deleterious T cell-mediated immunity. Although oral tolerance is an active process that involves emergence of CD4+ forkhead box p3 (Foxp3)+ regulatory T (Treg) cells in gut-associated lymphoid tissues (GALTs) for suppression of effector T (Teff) cells, how antigen-presenting cells initiate this process remains unclear. OBJECTIVE: We sought to determine the role of plasmacytoid dendritic cells (pDCs), which are known as unconventional antigen-presenting cells, in establishment of oral tolerance. METHODS: GALT-associated pDCs in wild-type mice were examined for their ability to induce differentiation of CD4+ Teff cells and CD4+Foxp3+ Treg cells in vitro. Wild-type and pDC-ablated mice were fed oral antigen to compare their intestinal generation of CD4+Foxp3+ Treg cells and induction of oral tolerance to protect against Teff cell-mediated allergic inflammation. RESULTS: GALT-associated pDCs preferentially generate CD4+Foxp3+ Treg cells rather than CD4+ Teff cells, and such generation requires an autocrine loop of TGF-ß for its robust production. A deficiency of pDCs abrogates antigen-specific de novo generation of CD4+Foxp3+ Treg cells occurring in GALT after antigenic feeding. Furthermore, the absence of pDCs impairs development of oral tolerance, which ameliorates the progression of delayed-type hypersensitivity and systemic anaphylaxis, as well as allergic asthma, accompanied by an enhanced antigen-specific CD4+ Teff cell response and antibody production. CONCLUSION: pDCs are required for establishing oral tolerance to prevent undesirable allergic responses, and they might serve a key role in maintaining gastrointestinal immune homeostasis.


Asunto(s)
Células Dendríticas/inmunología , Tolerancia Inmunológica/inmunología , Inmunidad Mucosa/inmunología , Mucosa Intestinal/inmunología , Animales , Linfocitos T CD4-Positivos/inmunología , Diferenciación Celular/inmunología , Tejido Linfoide/inmunología , Ratones
16.
Curr Top Microbiol Immunol ; 410: 47-71, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28900681

RESUMEN

Dendritic cells (DCs) comprise heterogeneous subsets, functionally classified into conventional DCs (cDCs) and plasmacytoid DCs (pDCs). DCs are considered to be essential antigen (Ag)-presenting cells (APCs) that play crucial roles in activation and fine-tuning of innate and adaptive immunity under inflammatory conditions, as well as induction of immune tolerance to maintain immune homeostasis under steady-state conditions. Furthermore, DC functions can be modified and influenced by stimulation with various extrinsic factors, such as ligands for pattern-recognition receptors (PRRs) and cytokines. On the other hand, treatment of DCs with certain immunosuppressive drugs and molecules leads to the generation of tolerogenic DCs that show downregulation of both the major histocompatibility complex (MHC) and costimulatory molecules, and not only show defective T-cell activation, but also possess tolerogenic properties including the induction of anergic T-cells and regulatory T (Treg) cells. To develop an effective strategy for Ag-specific intervention of T-cell-mediated immune disorders, we have previously established the modified DCs with moderately high levels of MHC molecules that are defective in the expression of costimulatory molecules that had a greater immunoregulatory property than classical tolerogenic DCs, which we therefore designated as regulatory DCs (DCreg). Herein, we integrate the current understanding of the role of DCs in the control of immune responses, and further provide new information of the characteristics of tolerogenic DCs and DCreg, as well as their regulation of immune responses and disorders.


Asunto(s)
Células Dendríticas , Tolerancia Inmunológica , Animales , Humanos , Linfocitos T Reguladores
17.
Biochem Biophys Rep ; 9: 29-35, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28955985

RESUMEN

Basophils, which are the rarest granulocytes, play crucial roles in protective immunity against parasites and development of allergic disorders. Although immunoglobulin (Ig)E-dependent responses via receptor for IgE (FcεRI) in basophils have been extensively studied, little is known about cell surface molecules that are selectively expressed on this cell subset to utilize the elimination in vivo through treatment with monoclonal antibody (mAb). Since CD200 receptor 3 (CD200R3) was exclusively expressed on basophils and mast cells (MCs) using a microarray screening, we have generated anti-CD200R3 mAb recognizing CD200R3A. In this study we examined the expression pattern of CD200R3A on leukocytes, and the influence of the elimination of basophils by anti-CD200R3A mAb on allergic responses. Flow cytometric analysis showed that CD200R3A was primarily expressed on basophils and MCs, but not on other leukocytes. Administration with anti-CD200R3A mAb led to the prominent specific depletion of tissue-resident and circulating basophils, but not MCs. Furthermore, in vivo depletion of basophils ameliorated IgE-mediated systemic and local anaphylaxis. Taken together, these findings suggest that CD200R3A is reliable cell surface marker for basophils in vivo, and targeting this unique molecule with mAb for the elimination of basophils may serve as a novel therapeutic strategy in ameliorating the allergic diseases.

18.
Bioconjug Chem ; 27(8): 1865-71, 2016 08 17.
Artículo en Inglés | MEDLINE | ID: mdl-27463562

RESUMEN

Mucosal vaccination is one of the most effective ways to reduce the risk of pandemics as a result of incorrect prediction of epidemic strains of influenza viruses or virus mutation. However, adjuvants and antigen carriers with potent immunostimulatory activities are a prerequisite for significant induction of mucosal immunity because most antigens are poorly immunogenic when solely applied to the mucosa. Our previous studies demonstrated that poly(N-vinylacetamide-co-acrylic acid) bearing d-octaarginine induced the secretion of antigen-specific immunoglobulin A (IgA) on the mucosa when nasally administered with virus antigens and that intranasal IgA reacts to viral strains other than the one used for immunization. Therefore, the present study evaluated capabilities of secreted IgA for protection against virus infection. When mice were inoculated with a mixture of inactivated H1N1 A/Puerto Rico/8/34 influenza viruses and d-octaarginine-linked polymers, antigen-specific secreted IgA was induced on the nasal mucosa. Immunized mice were completely protected from virus infection of the inoculated strain. To the contrary, mice nasally inoculated with inactivated viruses alone were infected with the homologous viruses presumably because of insignificant induction of secreted IgA. Results demonstrated that our polymer would be a promising adjuvant for mucosal vaccination.


Asunto(s)
Resinas Acrílicas/química , Subtipo H1N1 del Virus de la Influenza A/inmunología , Membrana Mucosa/inmunología , Oligopéptidos/química , Polímeros/química , Vacunación , Adyuvantes Inmunológicos/química , Adyuvantes Inmunológicos/farmacología , Animales , Femenino , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Ratones , Ratones Endogámicos BALB C , Oligopéptidos/inmunología
19.
Methods Mol Biol ; 1423: 291-308, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27142025

RESUMEN

Dendritic cells (DCs) are essential antigen-presenting cells (APCs) that consist of heterogeneous subsets, mainly classified as conventional DCs (cDCs) and plasmacytoid DCs (pDCs). CD205, an endocytic type I C-type lectin-like molecule that belongs to the mannose receptor family, is mainly expressed on CD8α(+) cDCs. However, it is unclear how CD205(+) cDCs control immune responses in vivo. To evaluate the contribution of CD205(+) cDCs to the immune system, we engineered knock-in (KI) mice that express the diphtheria toxin receptor (DTR) under the control of the Cd205 gene, which allows the selective conditional ablation of CD205(+) cDCs in vivo. Conditional ablation of CD205(+) cDCs impaired the antigen-specific priming of CD8(+) T cells to generate cytotoxic T lymphocytes (CTLs) mediated through cross presentation of soluble antigen. Upon microbial infection, CD205(+) cDCs contributed to the cross priming of CD8(+) T cells for generating antibacterial CTLs to efficiently eliminate pathogens. Here, we provide a protocol for the generation of bone marrow WT/CD205-DT chimeric mice, depletion of CD205(+) DCs and assessment of depletion efficiency, and protocols for in vivo cross presentation assay, CTL generation assay, and antibacterial immunity assay.


Asunto(s)
Antígenos CD/genética , Células de la Médula Ósea/citología , Células Dendríticas/citología , Factor de Crecimiento Similar a EGF de Unión a Heparina/metabolismo , Lectinas Tipo C/genética , Antígenos de Histocompatibilidad Menor/genética , Receptores de Superficie Celular/genética , Animales , Antígenos CD/metabolismo , Células de la Médula Ósea/inmunología , Linfocitos T CD8-positivos/inmunología , Reactividad Cruzada , Células Dendríticas/inmunología , Técnicas de Sustitución del Gen , Factor de Crecimiento Similar a EGF de Unión a Heparina/genética , Lectinas Tipo C/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Antígenos de Histocompatibilidad Menor/metabolismo , Regiones Promotoras Genéticas , Receptores de Superficie Celular/metabolismo , Linfocitos T Citotóxicos/inmunología
20.
Nat Commun ; 7: 11273, 2016 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-27068492

RESUMEN

Dendritic cells (DCs) comprise several subsets that are critically involved in the initiation and regulation of immunity. Clec4A4/DC immunoreceptor 2 (DCIR2) is a C-type lectin receptor (CLR) exclusively expressed on CD8α(-) conventional DCs (cDCs). However, how Clec4A4 controls immune responses through regulation of the function of CD8α(-) cDCs remains unclear. Here we show that Clec4A4 is a regulatory receptor for the activation of CD8α(-) cDCs that impairs inflammation and T-cell immunity. Clec4a4(-/-)CD8α(-) cDCs show enhanced cytokine production and T-cell priming following Toll-like receptor (TLR)-mediated activation. Furthermore, Clec4a4(-/-) mice exhibit TLR-mediated hyperinflammation. On antigenic immunization, Clec4a4(-/-) mice show not only augmented T-cell responses but also progressive autoimmune pathogenesis. Conversely, Clec4a4(-/-) mice exhibit resistance to microbial infection, accompanied by enhanced T-cell responses against microbes. Thus, our findings highlight roles of Clec4A4 in regulation of the function of CD8α(-) cDCs for control of the magnitude and quality of immune response.


Asunto(s)
Células Dendríticas/inmunología , Inmunidad Celular , Inflamación/patología , Receptores de Superficie Celular/metabolismo , Receptores Inmunológicos/metabolismo , Linfocitos T/inmunología , Animales , Infecciones Bacterianas/inmunología , Infecciones Bacterianas/prevención & control , Linfocitos T CD4-Positivos/inmunología , Antígenos CD8/metabolismo , Linfocitos T CD8-positivos/inmunología , Citocinas/biosíntesis , Encefalomielitis Autoinmune Experimental/inmunología , Encefalomielitis Autoinmune Experimental/patología , Epítopos/inmunología , Interacciones Huésped-Patógeno/inmunología , Ligandos , Ratones Endogámicos C57BL , Polisacáridos/metabolismo , Unión Proteica , Estructura Terciaria de Proteína , Receptores de Superficie Celular/química , Receptores Inmunológicos/química , Retroviridae/metabolismo , Receptores Toll-Like/metabolismo , Transducción Genética
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