RESUMEN
Posttranslational modifications can enhance immunogenicity of self-proteins. In several conditions, including hypertension, systemic lupus erythematosus, and heart failure, isolevuglandins (IsoLGs) are formed by lipid peroxidation and covalently bond with protein lysine residues. Here, we show that the murine class I major histocompatibility complex (MHC-I) variant H-2Db uniquely presents isoLG-modified peptides and developed a computational pipeline that identifies structural features for MHC-I accommodation of such peptides. We identified isoLG-adducted peptides from renal proteins, including sodium glucose transporter 2, cadherin 16, Kelch domain-containing protein 7A, and solute carrier family 23, that are recognized by CD8+ T cells in tissues of hypertensive mice, induce T cell proliferation in vitro, and prime hypertension after adoptive transfer. Finally, we find patterns of isoLG-adducted antigen restriction in class I human leukocyte antigens that are similar to those in murine analogs. Thus, we have used a combined computational and experimental approach to define likely antigenic peptides in hypertension.
Asunto(s)
Modelos Animales de Enfermedad , Hipertensión , Procesamiento Proteico-Postraduccional , Animales , Hipertensión/inmunología , Hipertensión/metabolismo , Hipertensión/patología , Ratones , Humanos , Linfocitos T CD8-positivos/inmunología , Autoantígenos/inmunología , Autoantígenos/metabolismo , Antígenos H-2/inmunología , Antígenos H-2/genética , Antígenos H-2/metabolismo , Péptidos/inmunología , Péptidos/metabolismoRESUMEN
The UV-mediated peptide exchange has enabled the generation of multiple different MHC multimer specificities in parallel, surpassing tedious individual refolding of MHC molecules with peptide ligands. Murine models are acknowledged as an effective tool for preclinical research to advance our understanding of immunological mechanisms, with the potential translatability of key learnings from mouse models to the clinic. The common inbred mouse strain BALB/c is frequently used in immunological research. However, for the BALB/c histocompatibility (H)-2 alleles availability of conditional ligand has been limited. To overcome this challenge, we design and experimentally validate conditional ligands restricted to murine MHC class I alleles H2Dd and H2Kd. In addition, we demonstrate the ability of the three H2d molecules and two additional C57BL/6 H2b molecules folded in-house with conditional ligands to generate fluorescently labeled peptide-H2 tetramers that allow staining of antigen-specific CD8+ T cells in splenocyte samples. Finally, we generate large peptide-H-2 multimer libraries with a DNA-barcode labeling system for high-throughput interrogation of CD8+ T cell specificity in murine splenocyte samples. Consequently, the described techniques will contribute to our understanding of the antigen-specific CD8+ T cell repertoire in murine preclinical models of various diseases.
Asunto(s)
Linfocitos T CD8-positivos , Péptidos , Animales , Ligandos , Ratones , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Péptidos/inmunología , Péptidos/química , Ratones Endogámicos C57BL , Antígenos H-2/inmunología , Antígenos H-2/metabolismo , Antígenos H-2/genética , Ratones Endogámicos BALB CRESUMEN
BACKGROUND: The formation of anti-major histocompatibility complex (MHC) antibodies is a significant barrier for many patients awaiting organ transplantation. Patients with preformed anti-MHC antibodies have limited options for suitable donors, and the formation of donor-specific anti-MHC antibodies after transplantation is a harbinger of graft rejection. Despite the recognized importance of anti-MHC antibodies, the mechanisms responsible for the differentiation of B cells after exposure to allogeneic antigens are poorly understood. METHODS: To evaluate the differentiation of B cells in response to allogeneic antigen, we used a model of H-2 b C57Bl/6 sensitization with H-2 d antigen. We used a class I MHC tetramer-based approach to identify allogeneic B cells and flow cytometric crossmatch to identify allogeneic IgM and IgG. RESULTS: We found that although the formation of anti-H-2 d IgG was robust, few class-switched B cells and germinal center B cells were formed. Antigen-specific B cells did not express classical memory B-cell markers after sensitization but had an IgM + CD21 + marginal zone B-cell phenotype. The frequency of marginal zone B cells increased after sensitization. Depletion of marginal zone B cells before sensitization or skin grafting resulted in a significant diminution of anti-H-2 d IgG and fewer germinal center B cells. Adoptive transfer experiments revealed that marginal zone B cells more efficiently differentiated into germinal center B cells and anti-donor IgG-producing cells than follicular B cells. CONCLUSIONS: These results demonstrate an important role for marginal zone B cells as a reservoir of alloreactive B cells that are activated by allogeneic antigens.
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Linfocitos B , Inmunoglobulina G , Isoanticuerpos , Ratones Endogámicos C57BL , Trasplante de Piel , Animales , Inmunoglobulina G/inmunología , Linfocitos B/inmunología , Isoanticuerpos/inmunología , Isoanticuerpos/sangre , Diferenciación Celular/inmunología , Ratones , Antígenos H-2/inmunología , Rechazo de Injerto/inmunología , Rechazo de Injerto/prevención & control , Trasplante Homólogo , Inmunoglobulina M/inmunología , Fenotipo , Centro Germinal/inmunologíaRESUMEN
Allogeneic stem cell transplantation (alloSCT) is a curative therapy for hematopoietic malignancies. The therapeutic effect relies on donor T cells and NK cells to recognize and eliminate malignant cells, known as the graft-versus-leukemia (GVL) effect. However, off target immune pathology, known as graft-versus-host disease (GVHD) remains a major complication of alloSCT that limits the broad application of this therapy. The presentation of recipient-origin alloantigen to donor T cells is the primary process initiating GVHD and GVL. Therefore, the understanding of spatial and temporal characteristics of alloantigen presentation is pivotal to attempts to separate beneficial GVL effects from detrimental GVHD. In this review, we discuss mouse models and the tools therein, that permit the quantification of alloantigen presentation after alloSCT.
Asunto(s)
Presentación de Antígeno/inmunología , Trasplante de Células Madre Hematopoyéticas , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/inmunología , Inmunología del Trasplante , Animales , Enfermedad Injerto contra Huésped/etiología , Efecto Injerto vs Leucemia/inmunología , Antígenos H-2/inmunología , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Trasplante de Células Madre Hematopoyéticas/métodos , Isoantígenos/inmunología , Ratones , Antígenos de Histocompatibilidad Menor/inmunología , Imitación Molecular/inmunología , Linfocitos T/inmunología , Linfocitos T/metabolismo , Trasplante HomólogoRESUMEN
CD8 T cell infiltration of the central nervous system (CNS) is necessary for host protection but contributes to neuropathology. Antigen presenting cells (APCs) situated at CNS borders are thought to mediate T cell entry into the parenchyma during neuroinflammation. The identity of the CNS-resident APC that presents antigen via major histocompatibility complex (MHC) class I to CD8 T cells is unknown. Herein, we characterize MHC class I expression in the naïve and virally infected brain and identify microglia and macrophages (CNS-myeloid cells) as APCs that upregulate H-2Kb and H-2Db upon infection. Conditional ablation of H-2Kb and H-2Db from CNS-myeloid cells allowed us to determine that antigen presentation via H-2Db, but not H-2Kb, was required for CNS immune infiltration during Theiler's murine encephalomyelitis virus (TMEV) infection and drives brain atrophy as a consequence of infection. These results demonstrate that CNS-myeloid cells are key APCs mediating CD8 T cell brain infiltration.
Asunto(s)
Células Presentadoras de Antígenos/patología , Encefalopatías/virología , Encéfalo/patología , Antígenos H-2/inmunología , Theilovirus/inmunología , Animales , Presentación de Antígeno , Células Presentadoras de Antígenos/virología , Atrofia , Encéfalo/inmunología , Encéfalo/virología , Encefalopatías/inmunología , Linfocitos T CD8-positivos/inmunología , Femenino , Macrófagos/patología , Macrófagos/virología , Imagen por Resonancia Magnética , Masculino , Ratones , Ratones Endogámicos C57BL , Microglía/patología , Microglía/virologíaRESUMEN
The CD8αß heterodimer plays a crucial role in the stabilization between major histocompatibility complex class I molecules (MHC-I) and the T cell receptor (TCR). The interaction between CD8 and MHC-I can be regulated by posttranslational modifications, which are proposed to play an important role in the development of CD8 T cells. One modification that has been proposed to control CD8 coreceptor function is ribosylation. Utilizing NAD+, the ecto-enzyme adenosine diphosphate (ADP) ribosyl transferase 2.2 (ART2.2) catalyzes the addition of ADP-ribosyl groups onto arginine residues of CD8α or ß chains and alters the interaction between the MHC and TCR complexes. To date, only interactions between modified CD8 and classical MHC-I (MHC-Ia), have been investigated and the interaction with non-classical MHC (MHC-Ib) has not been explored. Here, we show that ADP-ribosylation of CD8 facilitates the binding of the liver-restricted nonclassical MHC, H2-Q10, independent of the associated TCR or presented peptide, and propose that this highly regulated binding imposes an additional inhibitory leash on the activation of CD8-expressing cells in the presence of NAD+. These findings highlight additional important roles for nonclassical MHC-I in the regulation of immune responses.
Asunto(s)
ADP-Ribosilación/inmunología , Antígenos CD8/inmunología , Linfocitos T CD8-positivos/inmunología , Antígenos H-2/inmunología , Multimerización de Proteína/inmunología , ADP Ribosa Transferasas/genética , ADP Ribosa Transferasas/inmunología , ADP-Ribosilación/genética , Animales , Antígenos CD8/genética , Antígenos H-2/genética , Hígado/inmunología , Ratones , Ratones Noqueados , Multimerización de Proteína/genética , Receptores de Antígenos de Linfocitos T/genética , Receptores de Antígenos de Linfocitos T/inmunologíaRESUMEN
Simultaneous triggering of NK1.1 and MHC class I on NK cells gives a higher Ca2+ flux response compared to triggering the NK1.1 receptor alone. The data suggest a novel costimulatory role for MHC class I molecules on NK cell responses.
Asunto(s)
Antígenos Ly/inmunología , Calcio/metabolismo , Antígenos de Histocompatibilidad Clase I/inmunología , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/metabolismo , Subfamilia B de Receptores Similares a Lectina de Células NK/inmunología , Transducción de Señal , Animales , Antígenos H-2/genética , Antígenos H-2/inmunología , RatonesRESUMEN
The study was aimed at developing an accessible laboratory animal model to elucidate protective and pathological roles of immune mediators during Peste des petits ruminants virus (PPRV) infection. It is because of the critical roles of type I IFNs in anti-viral defense, we assessed the susceptibility of IFN receptor knock out (IFNR KO) mice to PPRV infection. IFNR KO mice were exceedingly susceptible to the infection but WT animals efficiently controlled PPRV. Accordingly, the PPRV infected IFNR KO mice gradually reduced their body weights and succumbed to the infection within 10 days irrespective of the dose and route of infection. The lower infecting doses predominantly induced immunopathological lesions. The viral antigens as well as the replicating PPRV were abundantly present in most of the critical organs such as brain, lungs, heart and kidneys of IFNR KO mice infected with high dose of the virus. Neutrophils and macrophages transported the replicating virus to central nervous system (CNS) and contributed to pathology while the elevated NK and T cell responses directly correlated with the resolution of PPRV infection in WT animals. Using an array of fluorescently labeled H-2Kb tetramers, we discovered four immunogenic epitopes of PPRV. The PPRV-peptides interacted well with H-2Kb in acellular and cellular assay as well as expanded the virus-specific CD8+ T cells in immunized or infected mice. Adoptively transferred CD8+ T cells helped control PPRV in infected mice. Our study therefore established and employed a mouse model for investigating the pathogenesis of PPRV. The model could be useful for elucidating the contribution of immune cells in disease progression as well as to test anti-viral agents.
Asunto(s)
Peste de los Pequeños Rumiantes/inmunología , Animales , Encéfalo/virología , Linfocitos T CD8-positivos/inmunología , Modelos Animales de Enfermedad , Antígenos H-2/inmunología , Inmunidad Innata , Inmunización , Pulmón/virología , Ratones , Ratones Endogámicos C57BL , Peste de los Pequeños Rumiantes/mortalidad , Peste de los Pequeños Rumiantes/patología , Virus de la Peste de los Pequeños Rumiantes/inmunología , Receptores de Interferón/fisiología , Vacunas Virales/inmunologíaRESUMEN
Intracranial (i.c.) infection of susceptible C57BL/6 mice with the neurotropic JHM strain of mouse hepatitis virus (JHMV) (a member of the Coronaviridae family) results in acute encephalomyelitis and viral persistence associated with an immune-mediated demyelinating disease. The present study was undertaken to better understand the molecular pathways evoked during innate and adaptive immune responses as well as the chronic demyelinating stage of disease in response to JHMV infection of the central nervous system (CNS). Using single-cell RNA sequencing analysis (scRNAseq) on flow-sorted CD45-positive (CD45+) cells enriched from brains and spinal cords of experimental mice, we demonstrate the heterogeneity of the immune response as determined by the presence of unique molecular signatures and pathways involved in effective antiviral host defense. Furthermore, we identify potential genes involved in contributing to demyelination as well as remyelination being expressed by both microglia and macrophages. Collectively, these findings emphasize the diversity of the immune responses and molecular networks at defined stages following viral infection of the CNS.IMPORTANCE Understanding the immunological mechanisms contributing to both host defense and disease following viral infection of the CNS is of critical importance given the increasing number of viruses that are capable of infecting and replicating within the nervous system. With this in mind, the present study was undertaken to evaluate the molecular signatures of immune cells within the CNS at defined times following infection with a neuroadapted murine coronavirus using scRNAseq. This approach has revealed that the immunological landscape is diverse, with numerous immune cell subsets expressing distinct mRNA expression profiles that are, in part, dictated by the stage of infection. In addition, these findings reveal new insight into cellular pathways contributing to control of viral replication as well as to neurologic disease.
Asunto(s)
Infecciones del Sistema Nervioso Central/inmunología , Infecciones del Sistema Nervioso Central/virología , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/virología , Interacciones Huésped-Patógeno/inmunología , Virus de la Hepatitis Murina/fisiología , Animales , Infecciones del Sistema Nervioso Central/genética , Infecciones del Sistema Nervioso Central/patología , Biología Computacional/métodos , Infecciones por Coronavirus/genética , Infecciones por Coronavirus/patología , Encefalomielitis/genética , Encefalomielitis/inmunología , Encefalomielitis/patología , Encefalomielitis/virología , Perfilación de la Expresión Génica , Antígenos H-2/genética , Antígenos H-2/inmunología , Interacciones Huésped-Patógeno/genética , Inmunidad Innata , Ratones , Análisis de Secuencia de ARN , Análisis de la Célula IndividualRESUMEN
BACKGROUND: Nonspecific immunosuppressive therapy for graft rejection and graft-versus-host disease (GVHD) is often accompanied by severe side effects such as opportunistic infections and cancers. Several approaches have been developed to suppress transplantation reactions using tolerogenic cells, including induction of FoxP3+ Tregs with antigen-loaded dendritic cells (DCs) and induction of CD4+IL-10+ cells with interleukin IL-10-producing DCs. Here, we assessed the effectiveness of both approaches in the suppression of graft rejection and GVHD. METHODS: IL-10-producing DCs were generated by the transfection of DCs with DNA constructs encoding mouse IL-10. Antigen-loaded DCs from C57BL/6 mice were generated by transfection with DNA constructs encoding antigenic determinants from the H2 locus of CBA mice which differ from the homologous antigenic determinants of C57BL/6 mice. RESULTS: We found that both IL-10-producing DCs and antigen-loaded immature DCs could suppress graft rejection and GVHD but through distinct nonspecific and antigen-specific mechanisms, respectively. Discussion. We provide data that the novel approach for DCs antigen loading using DNA constructs encoding distinct homologous determinants derived from major histocompatibility complex genes is effective in antigen-specific suppression of transplantation reactions. Such an approach eliminates the necessity of donor material use and may be useful in immunosuppressive therapy side effects prevention.
Asunto(s)
Células Dendríticas/inmunología , Epítopos/inmunología , Antígenos H-2/inmunología , Tolerancia Inmunológica , Animales , Células Dendríticas/metabolismo , Modelos Animales de Enfermedad , Epítopos/genética , Femenino , Orden Génico , Rechazo de Injerto/inmunología , Enfermedad Injerto contra Huésped/diagnóstico , Enfermedad Injerto contra Huésped/etiología , Enfermedad Injerto contra Huésped/terapia , Antígenos H-2/genética , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Plásmidos/genética , Subgrupos de Linfocitos T , Transfección , Trasplante HomólogoRESUMEN
T follicular helper (TFH) cells are critical in adaptive immune responses to pathogens and vaccines; however, what drives the initiation of their developmental program remains unclear. Studies suggest that a T cell antigen receptor (TCR)-dependent mechanism may be responsible for the earliest TFH cell-fate decision, but a critical aspect of the TCR has been overlooked: tonic TCR signaling. We hypothesized that tonic signaling influences early TFH cell development. Here, two murine TCR-transgenic CD4+ T cells, LLO56 and LLO118, which recognize the same antigenic peptide presented on major histocompatibility complex molecules but experience disparate strengths of tonic signaling, revealed low tonic signaling promotes TFH cell differentiation. Polyclonal T cells paralleled these findings, with naive Nur77 expression distinguishing TFH cell potential. Two mouse lines were also generated to both increase and decrease tonic signaling strength, directly establishing an inverse relationship between tonic signaling strength and TFH cell development. Our findings elucidate a central role for tonic TCR signaling in early TFH cell-lineage decisions.
Asunto(s)
Receptores de Antígenos de Linfocitos T/metabolismo , Transducción de Señal , Células T Auxiliares Foliculares/inmunología , Células T Auxiliares Foliculares/metabolismo , Animales , Antígenos/inmunología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Diferenciación Celular/inmunología , Antígenos H-2/inmunología , Inmunización , Inmunofenotipificación , Activación de Linfocitos/inmunología , Ratones , Ratones Noqueados , Ratones Transgénicos , Péptidos/inmunologíaRESUMEN
Intestinal microbiota have been proposed to induce commensal-specific memory T cells that cross-react with tumor-associated antigens. We identified major histocompatibility complex (MHC) class I-binding epitopes in the tail length tape measure protein (TMP) of a prophage found in the genome of the bacteriophage Enterococcus hirae Mice bearing E. hirae harboring this prophage mounted a TMP-specific H-2Kb-restricted CD8+ T lymphocyte response upon immunotherapy with cyclophosphamide or anti-PD-1 antibodies. Administration of bacterial strains engineered to express the TMP epitope improved immunotherapy in mice. In renal and lung cancer patients, the presence of the enterococcal prophage in stools and expression of a TMP-cross-reactive antigen by tumors correlated with long-term benefit of PD-1 blockade therapy. In melanoma patients, T cell clones recognizing naturally processed cancer antigens that are cross-reactive with microbial peptides were detected.
Asunto(s)
Antígenos de Neoplasias/inmunología , Bacteriófagos/inmunología , Enterococcus hirae/virología , Microbioma Gastrointestinal/inmunología , Antígenos de Histocompatibilidad Clase I/inmunología , Inmunoterapia/métodos , Neoplasias/terapia , Proteínas de la Cola de los Virus/inmunología , Animales , Anticuerpos Monoclonales/uso terapéutico , Antineoplásicos Alquilantes/uso terapéutico , Linfocitos T CD8-positivos/inmunología , Reacciones Cruzadas , Ciclofosfamida/uso terapéutico , Epítopos/inmunología , Heces/virología , Antígenos H-2/inmunología , Humanos , Ratones , Neoplasias/dietoterapia , Neoplasias/inmunología , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Receptor de Muerte Celular Programada 1/inmunología , Proteínas de la Cola de los Virus/uso terapéuticoRESUMEN
Theiler's murine encephalomyelitis virus (TMEV) infection of the CNS is cleared in C57BL/6 mice by a CD8 T cell response restricted by the MHC class I molecule H-2Db The identity and function of the APC(s) involved in the priming of this T cell response is (are) poorly defined. To address this gap in knowledge, we developed an H-2Db LoxP-transgenic mouse system using otherwise MHC class I-deficient C57BL/6 mice, thereby conditionally ablating MHC class I-restricted Ag presentation in targeted APC subpopulations. We observed that CD11c+ APCs are critical for early priming of CD8 T cells against the immunodominant TMEV peptide VP2121-130 Loss of H-2Db on CD11c+ APCs mitigates the CD8 T cell response, preventing early viral clearance and immunopathology associated with CD8 T cell activity in the CNS. In contrast, animals with H-2Db-deficient LysM+ APCs retained early priming of Db:VP2121-130 epitope-specific CD8 T cells, although a modest reduction in immune cell entry into the CNS was observed. This work establishes a model enabling the critical dissection of H-2Db-restricted Ag presentation to CD8 T cells, revealing cell-specific and temporal features involved in the generation of CD8 T cell responses. Employing this novel system, we establish CD11c+ cells as pivotal to the establishment of acute antiviral CD8 T cell responses against the TMEV immunodominant epitope VP2121-130, with functional implications both for T cell-mediated viral control and immunopathology.
Asunto(s)
Antígenos Virales/inmunología , Linfocitos T CD8-positivos/inmunología , Infecciones por Cardiovirus/inmunología , Genes MHC Clase I/inmunología , Antígenos H-2/inmunología , Theilovirus/inmunología , Animales , Presentación de Antígeno , Proteínas de la Cápside/inmunología , Epítopos de Linfocito T/inmunología , Epítopos Inmunodominantes/inmunología , Cinética , Ratones , Ratones Endogámicos C57BL , Ratones TransgénicosRESUMEN
Tolerogenic dendritic cells (tDCs) play a central role in the development of paternal antigen-specific regulatory T cells (Tregs) during pregnancy. We examined whether uterine CD11c+ antigen presenting cells (APC) induced paternal antigen-specific tolerance in allogeneic pregnant mice. Female BALB/c mice were mated with male DBA/2 mice, and their surface markers of APCs were studied using flow cytometry. After allogeneic mating, the uterine APCs exhibited significantly decreased expression of major histocompatibility complex (MHC) class II on day 3.5 post-coitus (pc) and day 5.5 pc. To analyze how seminal fluid affects surface markers of APCs, female BALB/c mice were mated with male mice that had undergone seminal vesicle excision (SVX). No reductions of MHC class II expression on APCs were seen in these mice. To analyze APC functions, a mixed lymphoid reaction (MLR) assay to paternal splenocytes was performed. Uterine APCs from allogeneic pregnant mice significantly suppressed the MLR reaction, but APCs from SVX mated mice did not suppress the MLR reaction Uterine APCs induced paternal antigen (Mls1a)-specific Treg development in vitro, but not in mice that mated with allogeneic SVX mice. These findings suggest that seminal fluid priming expands the paternal antigen-specific Treg population by inducing APCs development.
Asunto(s)
Células Dendríticas/inmunología , Tolerancia Inmunológica , Semen/inmunología , Linfocitos T Reguladores/inmunología , Útero/inmunología , Animales , Presentación de Antígeno , Antígenos CD11/metabolismo , Comunicación Celular/inmunología , Células Cultivadas , Células Dendríticas/metabolismo , Femenino , Antígenos H-2/inmunología , Antígenos H-2/metabolismo , Isoantígenos/inmunología , Isoantígenos/metabolismo , Masculino , Ratones , Modelos Animales , Embarazo , Semen/metabolismo , Linfocitos T Reguladores/metabolismo , Útero/citologíaRESUMEN
Recurrent Staphylococcus aureus infections are common, despite robust immune responses. S. aureus infection elicited protective antibody and T cell responses in mice that expressed the Major Histocompatibility Complex (MHC) of the H-2d haplotype, but not H-2b, demonstrating that host genetics drives individual variability. Vaccination with a-toxin or leukotoxin E (LukE) elicited similar antibody and T cell responses in mice expressing H-2d or H-2b, but vaccine-elicited responses were inhibited by concomitant infection in H-2d-expressing mice. These findings suggested that competitive binding of microbial peptides to host MHC proteins determines the specificity of the immunodominant response, which was confirmed using LukE-derived peptide-MHC tetramers. A vaccine that elicited T cell and antibody responses protected mice that expressed H-2d or H-2b, demonstrating that vaccination can overcome MHC-restricted immunodominance. Together, these results define how host genetics determine whether immunity elicted by S. aureus is protective and provide a mechanistic roadmap for future vaccine design.
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Interacciones Huésped-Patógeno/inmunología , Tolerancia Inmunológica , Epítopos Inmunodominantes/inmunología , Complejo Mayor de Histocompatibilidad/inmunología , Infecciones Estafilocócicas/inmunología , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/inmunología , Animales , Modelos Animales de Enfermedad , Exotoxinas/inmunología , Antígenos H-2/inmunología , Ratones , Unión Proteica , Infecciones Estafilocócicas/prevención & control , Linfocitos T/inmunología , Linfocitos T/metabolismo , VacunaciónAsunto(s)
Susceptibilidad a Enfermedades , Enfermedad Injerto contra Huésped/tratamiento farmacológico , Enfermedad Injerto contra Huésped/etiología , Integrina alfa4beta1/antagonistas & inhibidores , Terapia Molecular Dirigida , Animales , Biomarcadores , Modelos Animales de Enfermedad , Antígenos H-2/genética , Antígenos H-2/inmunología , Trasplante de Células Madre Hematopoyéticas , Integrina alfa4beta1/genética , Integrina alfa4beta1/metabolismo , Ratones , Linfocitos T/inmunología , Linfocitos T/metabolismo , Trasplante HomólogoRESUMEN
Rhoptry proteins (ROPs) are involved in the cell invasion and parasitophorous vacuole (PV) formation and also vital for survival of Toxoplasma gondii (T. gondii) within host cells. ROP8 have a main role during the early phase of infection and can express in tachyzoite and bradyzoite forms. In the present study, we designed a novel multi-epitope DNA vaccine encoding the potential B and T-cell epitopes from ROP8 protein to evaluate the immunity and protective efficacy against acute T. gondii infection in BALB/c mice. For this purpose, several bioinformatics online servers were used. At first, the potential epitopes were selected for T and B cells using immune epitope database (IEDB) and BCPREDS online services. Then, the selected epitopes were fused together by SAPGTP linker. Finally, the physico-chemical features, secondary and tertiary structures, antigenicity, and allergenicity of the peptide were evaluated through different bioinformatics tools. Lastly, the multi-epitope peptide was successfully cloned into pcDNA3.1 expression vector. The DNA vaccine was subcutaneously injected into BALB/c mice and the immune responses of the vaccinated mice and controls were determined. The obtained results revealed that the multi-epitope ROP8 peptide has 183 amino acid residues with average molecular weight (MW) of 18.974 kDa. More than 98 % residues of the peptide were incorporated in favored and allowed regions of the Ramachandran plot. The antigenicity of multi-epitope peptide were estimated 0.8751 and 0.7649 by ANTIGENpro and VaxiJen servers, respectively. BALB/c mice immunized with DNA vaccine showed significantly increased the level of specific anti-T. gondii antibodies (P < 0.05), and a mixed IgG1/IgG2a response with predominance of IgG2a production. The immunized mice also displayed a TH1-type cellular immune response with production of IFN-γ and prolonged survival time, compared with the control groups (P < 0.05). The findings revealed that the multi-epitope ROP8 DNA vaccine induced strong humoral and cellular responses and prolonged the survival time in BALB/c mice, suggesting selection of potential epitopes may be a promising strategy for the design of multi-epitope-based vaccines.
Asunto(s)
Linfocitos B/inmunología , Epítopos/inmunología , Vacunas Antiprotozoos/inmunología , Linfocitos T/inmunología , Toxoplasma/inmunología , Toxoplasmosis/prevención & control , Vacunas de ADN/inmunología , Secuencia de Aminoácidos , Animales , Anticuerpos Antiprotozoarios/inmunología , Antígenos de Protozoos/inmunología , Linfocitos B/metabolismo , Modelos Animales de Enfermedad , Mapeo Epitopo , Femenino , Antígenos H-2/inmunología , Inmunización , Ratones , Oligopéptidos/química , Oligopéptidos/inmunología , Oligopéptidos/metabolismo , Vacunas Antiprotozoos/administración & dosificación , Linfocitos T/metabolismo , Toxoplasmosis/parasitología , Vacunación , Vacunas de ADN/administración & dosificaciónRESUMEN
Following antigen stimulation, naïve T cells differentiate into memory cells that mediate antigen clearance more efficiently upon repeat encounter. Donor-specific tolerance can be achieved in a subset of transplant recipients, but some of these grafts are rejected after years of stability, often following infections. Whether T cell memory can develop from a tolerant state and whether these formerly tolerant patients develop antidonor memory is not known. Using a mouse model of cardiac transplantation in which donor-specific tolerance is induced with costimulation blockade (CoB) plus donor-specific transfusion (DST), we have previously shown that systemic infection with Listeria monocytogenes (Lm) months after transplantation can erode or transiently abrogate established tolerance. In this study, we tracked donor-reactive T cells to investigate whether memory can be induced when alloreactive T cells are activated in the setting of tolerance. We show alloreactive T cells persist after induction of cardiac transplantation tolerance, but fail to acquire a memory phenotype despite becoming antigen experienced. Instead, donor-reactive T cells develop T cell-intrinsic dysfunction evidenced when removed from the tolerant environment. Notably, Lm infection after tolerance did not rescue alloreactive T cell memory differentiation or functionality. CoB and antigen persistence were sufficient together but not separately to achieve alloreactive T cell dysfunction, and conventional immunosuppression could substitute for CoB. Antigen persistence was required, as early but not late surgical allograft removal precluded the acquisition of T cell dysfunction. Our results demonstrate transplant tolerance-associated T cell-intrinsic dysfunction that is resistant to memory development even after Lm-mediated disruption of tolerance.
Asunto(s)
Supervivencia de Injerto/inmunología , Tolerancia Inmunológica/inmunología , Subgrupos de Linfocitos T/inmunología , Inmunología del Trasplante , Aloinjertos , Animales , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/trasplante , Factores de Transcripción Forkhead/análisis , Genes Reporteros , Rechazo de Injerto/inmunología , Antígenos H-2/inmunología , Trasplante de Corazón , Antígenos de Histocompatibilidad Clase II/inmunología , Memoria Inmunológica , Isoantígenos/inmunología , Listeria monocytogenes , Listeriosis/inmunología , Transfusión de Linfocitos , Ratones , Ratones Congénicos , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Complicaciones Posoperatorias/inmunología , Linfocitos T Reguladores/inmunología , Donantes de TejidosRESUMEN
BACKGROUND/AIM: Leukocyte activation is thought to be a major step in sepsis-induced pulmonary edema. We attempted to confirm whether pulmonary edema can be reproduced under intravital microscopy in a model of transfusion-related acute lung injury (TRALI) using MHC class I-specific antibody. MATERIALS AND METHODS: The surface pulmonary microcirculation was observed using an epi-fluorescence microscope through a thoracic window in 50 male mice. Monoclonal MHC class I-specific antibody (Ab) was administered to the animals, while the control group received saline. The leukocytes and macro-molecular leakage in the pulmonary circulation were analyzed. RESULTS: Leukocytes accumulated in the capillaries (52.5±12.7 leukocytes per designated area in Ab group vs. 20.8±3.1 in control). The air-containing alveolus area significantly shrank from 2,224.9±934.9 µm2 to 509.7±380.8 µm2 in the Ab group. CONCLUSION: Pulmonary edema develops rapidly following leukocyte accumulation in the lung. We confirmed that leukocyte accumulation without an underlining condition is sufficient to induce pulmonary edema.
Asunto(s)
Anticuerpos Monoclonales/efectos adversos , Antígenos H-2/inmunología , Edema Pulmonar/etiología , Edema Pulmonar/patología , Lesión Pulmonar Aguda/etiología , Lesión Pulmonar Aguda/patología , Animales , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/farmacología , Biomarcadores , Biopsia , Recuento de Células Sanguíneas , Análisis de los Gases de la Sangre , Modelos Animales de Enfermedad , Inyecciones Intravenosas , Masculino , Ratones , Imagen Óptica , Edema Pulmonar/diagnóstico por imagenRESUMEN
Experimental autoimmune encephalomyelitis is a model for multiple sclerosis. Here we show that induction generates successive waves of clonally expanded CD4+, CD8+ and γδ+ T cells in the blood and central nervous system, similar to gluten-challenge studies of patients with coeliac disease. We also find major expansions of CD8+ T cells in patients with multiple sclerosis. In autoimmune encephalomyelitis, we find that most expanded CD4+ T cells are specific for the inducing myelin peptide MOG35-55. By contrast, surrogate peptides derived from a yeast peptide major histocompatibility complex library of some of the clonally expanded CD8+ T cells inhibit disease by suppressing the proliferation of MOG-specific CD4+ T cells. These results suggest that the induction of autoreactive CD4+ T cells triggers an opposing mobilization of regulatory CD8+ T cells.