RESUMEN
The molecular mechanisms that link the sympathetic stress response and inflammation remain obscure. Here we found that the transcription factor Nr4a1 regulated the production of norepinephrine (NE) in macrophages and thereby limited experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis. Lack of Nr4a1 in myeloid cells led to enhanced NE production, accelerated infiltration of leukocytes into the central nervous system (CNS) and disease exacerbation in vivo. In contrast, myeloid-specific deletion of tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine biosynthesis, protected mice against EAE. Furthermore, we found that Nr4a1 repressed autocrine NE production in macrophages by recruiting the corepressor CoREST to the Th promoter. Our data reveal a new role for macrophages in neuroinflammation and identify Nr4a1 as a key regulator of catecholamine production by macrophages.
Asunto(s)
Sistema Nervioso Central/inmunología , Encefalomielitis Autoinmune Experimental/inmunología , Inflamación/inmunología , Macrófagos/inmunología , Miembro 1 del Grupo A de la Subfamilia 4 de Receptores Nucleares/inmunología , Sistema Nervioso Simpático/inmunología , Animales , Línea Celular , Células Cultivadas , Sistema Nervioso Central/metabolismo , Modelos Animales de Enfermedad , Encefalomielitis Autoinmune Experimental/genética , Encefalomielitis Autoinmune Experimental/metabolismo , Expresión Génica/inmunología , Humanos , Inflamación/genética , Inflamación/metabolismo , Macrófagos/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Microscopía Confocal , Esclerosis Múltiple/inmunología , Esclerosis Múltiple/patología , Células Mieloides/inmunología , Células Mieloides/metabolismo , Norepinefrina/inmunología , Norepinefrina/metabolismo , Miembro 1 del Grupo A de la Subfamilia 4 de Receptores Nucleares/genética , Miembro 1 del Grupo A de la Subfamilia 4 de Receptores Nucleares/metabolismo , Conejos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sistema Nervioso Simpático/metabolismo , Tirosina 3-Monooxigenasa/genética , Tirosina 3-Monooxigenasa/inmunología , Tirosina 3-Monooxigenasa/metabolismoRESUMEN
Following a respiratory virus infection, CXCR3hi CX3CR1lo and CXCR3lo CX3CR1hi CD8 T cells localize to different compartments within the lung and play an important role in host resistance, but mechanisms governing their optimal generation are poorly defined. We serendipitously found that B cell-deficient (µMT-/-) mice were highly resistant to lethal infection with a virulent poxvirus strain and that depletion of CD8 T cells rendered these mice susceptible to infection. B cells were not required for the expansion of virus-specific CD8 T cells, but a greater proportion of activated CD8 T cells acquired an effector-like CXCR3lo CX3CR1hi phenotype in the absence of B cells. After recovery from infection, CD8 T cells in µMT-/- mice contracted normally but failed to survive and seed the memory cell pool in both the lungs and spleen. These findings reveal a previously unappreciated role for B cells in regulating the balance between CD8 T cell-mediated resistance against respiratory viral infection and memory cell development.IMPORTANCE B cells play critical role in host resistance against many respiratory viral infections. However, the role of B cells beyond antibody-producing cells is less well defined. In this study, we made a surprising observation that mice lacking B cells were more resistant to respiratory infection with vaccinia virus than wild-type mice. This enhanced resistance was mediated by CD8 T cells because when we depleted CD8 T cells in B cell-deficient mice, these mice were unable to survive the infection. Interestingly, CD8 T cells in B cell-deficient mice were skewed more toward effector phenotype and less toward memory phenotype, which resulted in severely compromised memory CD8 T cell development. Thus, our study shows a novel role of B cells as regulators of CD8 T cell-mediated host resistance and memory CD8 T cell formation during respiratory viral infection.
Asunto(s)
Linfocitos B/inmunología , Linfocitos T CD8-positivos/inmunología , Infecciones del Sistema Respiratorio/inmunología , Infecciones del Sistema Respiratorio/virología , Virosis/inmunología , Animales , Receptor 1 de Quimiocinas CX3C/metabolismo , Femenino , Memoria Inmunológica , Inmunoterapia Adoptiva , Pulmón , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Receptores CXCR3/metabolismo , Bazo , Virus Vaccinia/inmunologíaRESUMEN
The transition of effector T cells or memory precursors into distinct long-lived memory T cell subsets is not well understood. Although many molecules made by APCs can contribute to clonal expansion and effector cell differentiation, it is not clear if clonal contraction and memory development is passive or active. Using respiratory virus infection, we found that CD8 T cells that cannot express the TNF family molecule lymphotoxin-like, exhibits inducible expression, competes with HSV glycoprotein D for herpes virus entry mediator, a receptor expressed by T lymphocytes (LIGHT) are unimpaired in their initial response and clonally expand to form effector cell pools. Thereafter, LIGHT-deficient CD8 T cells undergo strikingly enhanced clonal contraction with resultant compromised accumulation of both circulating and tissue-resident memory cells. LIGHT expression at the peak of the effector response regulates the balance of several pro- and antiapoptotic genes, including Akt, and has a preferential impact on the development of the peripheral memory population. These results underscore the importance of LIGHT activity in programming memory CD8 T cell development, and suggest that CD8 effector T cells can dictate their own fate into becoming memory cells by expressing LIGHT.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Memoria Inmunológica/inmunología , Infecciones del Sistema Respiratorio/inmunología , Miembro 14 de la Superfamilia de Ligandos de Factores de Necrosis Tumoral/inmunología , Virosis/inmunología , Animales , Diferenciación Celular/inmunología , Femenino , Ratones , Ratones Endogámicos C57BL , Infecciones del Sistema Respiratorio/virologíaRESUMEN
Respiratory infection with vaccinia virus (VacV) elicits robust CD8+ T cell responses that play an important role in host resistance. In the lung, VacV encounters multiple tissue-resident antigen-presenting cell (APC) populations, but which cell plays a dominant role in priming of virus-specific CD8+ effector T cell responses remains poorly defined. We used Batf3-/- mice to investigate the impact of CD103+ and CD8α+ dendritic cell (DC) deficiency on anti-VacV CD8+ T cell responses. We found that Batf3-/- mice were more susceptible to VacV infection, exhibiting profound weight loss, which correlated with impaired accumulation of gamma interferon (IFN-γ)-producing CD8+ T cells in the lungs. This was largely due to defective priming since early in the response, antigen-specific CD8+ T cells in the draining lymph nodes of Batf3-/- mice expressed significantly reduced levels of Ki67, CD25, and T-bet. These results underscore a specific role for Batf3-dependent DCs in regulating priming and expansion of effector CD8+ T cells necessary for host resistance against acute respiratory VacV infection.IMPORTANCE During respiratory infection with vaccinia virus (VacV), a member of Poxviridae family, CD8+ T cells play important role in resolving the primary infection. Effector CD8+ T cells clear the virus by accumulating in the infected lungs in large numbers and secreting molecules such as IFN-γ that kill virally infected cells. However, precise cell types that regulate the generation of effector CD8+ T cells in the lungs are not well defined. Dendritic cells (DCs) are a heterogeneous population of immune cells that are recognized as key initiators and regulators of T-cell-mediated immunity. In this study, we reveal that a specific subset of DCs that are dependent on the transcription factor Batf3 for their development regulate the magnitude of CD8+ T cell effector responses in the lungs, thereby providing protection during pulmonary VacV infection.
Asunto(s)
Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/análisis , Linfocitos T CD8-positivos/inmunología , Células Dendríticas/química , Células Dendríticas/inmunología , Infecciones por Poxviridae/inmunología , Proteínas Represoras/análisis , Infecciones del Sistema Respiratorio/inmunología , Virus Vaccinia/inmunología , Animales , Antígenos CD/análisis , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/deficiencia , Antígenos CD8/análisis , Cadenas alfa de Integrinas/análisis , Ratones , Ratones Noqueados , Proteínas Represoras/deficienciaRESUMEN
Cognate interactions between T follicular helper (Tfh) cells and B cells are essential for promoting protective Ab responses. Whereas costimulatory receptors such as ICOS are accepted as being important for the induction of Tfh cell fate decision, other molecules may play key roles in amplifying or maintaining the Tfh phenotype. In this study, with vaccinia virus infection in mice, we show that OX40 was expressed on Tfh cells that accumulated at the T/B borders in the white pulp of the spleen and that OX40-dependent signals directly shaped the magnitude and quality of the their response to viral Ags. OX40 deficiency in Tfh cells profoundly impaired the acquisition of germinal center (GC) B cell phenotype, plasma cell generation, and virus-specific Ab responses. Most significantly, we found that sustained interactions between OX40 and its ligand, OX40L, beyond the time of initial encounter with dendritic cells were required for the persistence of high numbers of Tfh and GC B cells. Interestingly, OX40 was coexpressed with ICOS on Tfh cells in and around the GC, and ICOS-ICOSL interactions were similarly crucial at late times for maintenance of the Tfh and GC B cells. Thus, OX40 and ICOS act in a cooperative, nonredundant manner to maximize and prolong the Tfh response that is generated after acute virus infection.
Asunto(s)
Proteína Coestimuladora de Linfocitos T Inducibles/inmunología , Activación de Linfocitos/inmunología , Receptores OX40/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Animales , Linfocitos B/inmunología , Modelos Animales de Enfermedad , Femenino , Citometría de Flujo , Técnica del Anticuerpo Fluorescente , Centro Germinal/inmunología , Proteína Coestimuladora de Linfocitos T Inducibles/metabolismo , Glicoproteínas de Membrana/inmunología , Glicoproteínas de Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ligando OX40 , Infecciones por Poxviridae/inmunología , Análisis por Matrices de Proteínas , Receptores OX40/metabolismo , Linfocitos T Colaboradores-Inductores/metabolismo , Factores de Necrosis Tumoral/inmunología , Factores de Necrosis Tumoral/metabolismo , Virus VacciniaRESUMEN
Mucosal immunity to reinfection with a highly virulent virus requires the accumulation and persistence of memory CD8 T cells at the site of primary infection. These cells may derive from memory precursor effector cells (MPECs), which are distinct from short-lived effector cells that provide acute protection but are often destined to die. Using respiratory virus infection, we show that herpes virus entry mediator (HVEM; TNFRSF14), a member of the TNF receptor superfamily, provides key signals for MPEC persistence. HVEM-deficient CD8 T cells expanded normally but were skewed away from MPECs with resultant poor development of circulating and lung-resident memory cells. HVEM was selectively expressed on MPECs whereas MPECs deficient in HVEM failed to survive in adoptive transfer recipients. As a consequence, HVEM-deficient recipients failed to afford protection against respiratory reinfection with influenza virus. HVEM therefore represents a critical signal for MPECs and development of protective mucosal CD8 T cell memory.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Virus de la Influenza A/inmunología , Infecciones por Orthomyxoviridae/inmunología , Células Precursoras de Linfocitos T/inmunología , Miembro 14 de Receptores del Factor de Necrosis Tumoral/metabolismo , Traslado Adoptivo , Animales , Linfocitos T CD8-positivos/virología , Autorrenovación de las Células , Células Cultivadas , Modelos Animales de Enfermedad , Femenino , Inmunidad Mucosa , Memoria Inmunológica , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Células Precursoras de Linfocitos T/virología , Miembro 14 de Receptores del Factor de Necrosis Tumoral/genéticaRESUMEN
Phenotypically diverse memory CD8+ T cells are present in the lungs that either re-circulate or reside within the tissue. Understanding the key cellular interactions that regulate the generation and then persistence of these different subsets is of great interest. Recently, DNGR-1+ dendritic cell (DC) mediated priming was reported to control the generation of lung-resident but not circulating memory cells following respiratory viral infection. Here, we report an important role for Ly6C+ inflammatory monocytes (IMs) in contributing to the persistence of memory CD8+ T cells but not their generation. Effector CD8+ T cells expanded and contracted normally in the absence of IMs, but the memory compartment declined significantly over time. Quite unexpectedly, this defect was confined to tissue resident and circulating CXCR3hi CX3CR1lo memory cells but not CXCR3hi CX3CR1int and CXCR3lo CX3CR1hi subsets. Thus, two developmentally distinct innate cells orchestrate the generation and persistence of memory T cell subsets following a respiratory virus infection. See also: News and Commentary by Lafouresse & Groom.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Receptor 1 de Quimiocinas CX3C/metabolismo , Memoria Inmunológica , Inflamación/patología , Pulmón/inmunología , Monocitos/patología , Receptores CXCR3/metabolismo , Infecciones del Sistema Respiratorio/virología , Administración Intranasal , Animales , Proliferación Celular , Femenino , Células HeLa , Humanos , Inmunidad Innata , Pulmón/patología , Pulmón/virología , Ratones Endogámicos C57BL , Receptores CCR2/deficiencia , Receptores CCR2/metabolismo , Infecciones del Sistema Respiratorio/inmunología , Subgrupos de Linfocitos T/inmunología , Virus Vaccinia/fisiologíaRESUMEN
Pbx1 controls chromatin accessibility to a large number of genes and is entirely conserved between mice and humans. The Pbx1-d dominant-negative isoform is more frequent in CD4(+) T cells from lupus patients than from healthy controls. Pbx1-d is associated with the production of autoreactive T cells in mice carrying the Sle1a1 lupus-susceptibility locus. Transgenic (Tg) expression of Pbx1-d in CD4(+) T cells reproduced the phenotypes of Sle1a1 mice, with increased inflammatory functions of CD4(+) T cells and impaired Foxp3(+) regulatory T cell (Treg) homeostasis. Pbx1-d-Tg expression also expanded the number of follicular helper T cells (TFHs) in a cell-intrinsic and Ag-specific manner, which was enhanced in recall responses and resulted in Th1-biased Abs. Moreover, Pbx1-d-Tg CD4(+) T cells upregulated the expression of miR-10a, miR-21, and miR-155, which were implicated in Treg and follicular helper T cell homeostasis. Our results suggest that Pbx1-d impacts lupus development by regulating effector T cell differentiation and promoting TFHs at the expense of Tregs. In addition, our results identify Pbx1 as a novel regulator of CD4(+) T cell effector function.
Asunto(s)
Diferenciación Celular/inmunología , Proteínas de Unión al ADN/inmunología , Lupus Eritematoso Sistémico/inmunología , Proteínas Proto-Oncogénicas/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Linfocitos T Reguladores/inmunología , Animales , Citometría de Flujo , Proteínas de Homeodominio/inmunología , Humanos , Inmunohistoquímica , Ratones , Ratones Transgénicos , Reacción en Cadena de la Polimerasa , Factor de Transcripción 1 de la Leucemia de Células Pre-B , Factores de Transcripción/inmunologíaRESUMEN
PTPN22 (protein tyrosine phosphatase non receptor 22) encodes a tyrosine phosphatase that functions as a key regulator of immune homeostasis. In particular, PTPN22 inhibits T-cell receptor signaling and selectively promotes type I interferon responses in myeloid cells. To date, there is little information on the CD8 T-cell-intrinsic role of PTPN22 in response to a viral pathogen. We unexpectedly found that PTPN22-deficient virus-specific CD8 T cells failed to accumulate in wild-type hosts after lymphocytic choriomeningitis virus infection. Lack of PTPN22 expression altered CD8 T-cell activation and antiviral cytokine production, but did not significantly affect the composition of effector and memory cell precursors. Most significantly, in vivo, PTPN22-deficient CD8 T cells showed a profound defect in upregulating STAT-1 after lymphocytic choriomeningitis virus infection and considerably less phosphorylation of STAT-1 in response to IFN-α treatment in vitro compared with their wild-type counterparts. In stark contrast, following transfer into lymphopenic mice, CD8 T-cell expansion and central-like phenotype, was considerably increased in the absence of PTPN22. Collectively, our results suggest that PTPN22 has dual roles in T-cell clonal expansion and effector function; whereas it promotes antigen-driven responses during acute infection by positively regulating interferon signaling in T cells, PTPN22 inhibits homeostatic-driven proliferation.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Homeostasis , Virus de la Coriomeningitis Linfocítica/fisiología , Proteína Tirosina Fosfatasa no Receptora Tipo 22/metabolismo , Animales , Biomarcadores/metabolismo , Proliferación Celular , Citocinas/metabolismo , Interferón Tipo I/metabolismo , Activación de Linfocitos/inmunología , Coriomeningitis Linfocítica/inmunología , Coriomeningitis Linfocítica/virología , Ratones Endogámicos C57BL , Fosforilación , Proteína Tirosina Fosfatasa no Receptora Tipo 22/deficiencia , Factor de Transcripción STAT1/metabolismo , Transducción de Señal , Regulación hacia ArribaRESUMEN
UNLABELLED: In establishing a respiratory infection, vaccinia virus (VACV) initially replicates in airway epithelial cells before spreading to secondary sites of infection, mainly the draining lymph nodes, spleen, gastrointestinal tract, and reproductive organs. We recently reported that interferon gamma (IFN-γ) produced by CD8 T cells ultimately controls this disseminated infection, but the relative contribution of IFN-γ early in infection is unknown. Investigating the role of innate immune cells, we found that the frequency of natural killer (NK) cells in the lung increased dramatically between days 1 and 4 postinfection with VACV. Lung NK cells displayed an activated cell surface phenotype and were the primary source of IFN-γ prior to the arrival of CD8 T cells. In the presence of an intact CD8 T cell compartment, depletion of NK cells resulted in increased lung viral load at the time of peak disease severity but had no effect on eventual viral clearance, disease symptoms, or survival. In sharp contrast, RAG(-/-) mice devoid of T cells failed to control VACV and succumbed to infection despite a marked increase in NK cells in the lung. Supporting an innate immune role for NK cell-derived IFN-γ, we found that NK cell-depleted or IFN-γ-depleted RAG(-/-) mice displayed increased lung VACV titers and dissemination to ovaries and a significantly shorter mean time to death compared to untreated NK cell-competent RAG(-/-) controls. Together, these findings demonstrate a role for IFN-γ in aspects of both the innate and adaptive immune response to VACV and highlight the importance of NK cells in T cell-independent control of VACV in the respiratory tract. IMPORTANCE: Herein, we provide the first systematic evaluation of natural killer (NK) cell function in the lung after infection with vaccinia virus, a member of the Poxviridae family. The respiratory tract is an important mucosal site for entry of many human pathogens, including poxviruses, but precisely how our immune system defends the lung against these invaders remains unclear. Natural killer cells are a type of cytotoxic lymphocyte and part of our innate immune system. In recent years, NK cells have received increasing levels of attention following the discovery that different tissues contain specific subsets of NK cells with distinctive phenotypes and function. They are abundant in the lung, but their role in defense against respiratory viruses is poorly understood. What this study demonstrates is that NK cells are recruited, activated, and contribute to protection of the lung during a severe respiratory infection with vaccinia virus.
Asunto(s)
Interferón gamma/metabolismo , Células Asesinas Naturales/inmunología , Infecciones del Sistema Respiratorio/inmunología , Virus Vaccinia/inmunología , Vaccinia/inmunología , Animales , Linfocitos T CD8-positivos/inmunología , Femenino , Pulmón/inmunología , Pulmón/virología , Depleción Linfocítica , Ratones Endogámicos C57BL , Ratones Noqueados , Ovario/virología , Análisis de Supervivencia , Carga ViralAsunto(s)
Proteína Adaptadora de Señalización NOD2/inmunología , Linfocitos T/inmunología , Animales , Diferenciación Celular , Ratones , Proteína Adaptadora de Señalización NOD2/deficiencia , Transducción de Señal , Linfocitos T/citología , Toxoplasma/inmunología , Toxoplasmosis/inmunología , Toxoplasmosis/metabolismoRESUMEN
CD8 T cells are a key component of immunity to many viral infections. They achieve this through using an array of effector mechanisms, but precisely which component/s are required for protection against a respiratory orthopox virus infection remains unclear. Using a model of respiratory vaccinia virus infection in mice, we could specifically determine the relative contribution of perforin, TRAIL, and IFN-γ-mediated pathways in protection against virus induced morbidity and mortality. Unexpectedly, we observed that protection against death was mediated by IFN-γ without any involvement of the perforin or TRAIL-dependent pathways. IFN-γ mRNA and protein levels in the lung peaked between days 3 and 6 postinfection. This enhanced response coincided with the emergence of virus-specific CD8 T cells in the lung and the cessation of weight loss. Transfer experiments indicated that CD8 T cell-autonomous expression of IFN-γ restricts virus-induced lung pathology and dissemination to visceral tissues and is necessary for clearance of virus. Most significantly, we show that CD8 T cell-derived IFN-γ is sufficient to protect mice in the absence of CD4 and B-lymphocytes. Thus, our findings reveal a previously unappreciated mechanism by which effector CD8 T cells afford protection against a highly virulent respiratory orthopox virus infection.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Interferón gamma/inmunología , Pulmón/inmunología , Enfermedades Respiratorias/inmunología , Virus Vaccinia/inmunología , Vaccinia/inmunología , Animales , Linfocitos B/inmunología , Linfocitos B/patología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/patología , Linfocitos T CD8-positivos/patología , Interferón gamma/genética , Pulmón/patología , Ratones , Ratones Noqueados , Enfermedades Respiratorias/genética , Enfermedades Respiratorias/patología , Vaccinia/genética , Vaccinia/patologíaRESUMEN
Host innate immune responses to DNA viruses involve members of the nucleotide-binding domain, leucine-rich repeat and pyrin domain containing protein (NLRP) family, which form "inflammasomes" that activate caspase-1, resulting in proteolytic activation of cytokines interleukin (IL)-1ß and IL-18. We hypothesized that DNA viruses would target inflammasomes to overcome host defense. A Vaccinia virus (VACV) B-cell CLL/lymphoma 2 (Bcl-2) homolog, F1L, was demonstrated to bind and inhibit the NLR family member NLRP1 in vitro. Moreover, infection of macrophages in culture with virus lacking F1L (ΔF1L) caused increased caspase-1 activation and IL-1ß secretion compared with wild-type virus. Virulence of ΔF1L virus was attenuated in vivo, causing altered febrile responses, increased proteolytic processing of caspase-1, and more rapid inflammation in lungs of infected mice without affecting cell death or virus replication. Furthermore, we found that a hexapeptide from F1L is necessary and sufficient for inhibiting the NLRP1 inflammasome in vitro, thus identifying a peptidyl motif required for binding and inhibiting NLRP1. The functional importance of this NLRP1-binding motif was further confirmed by studies of recombinant ΔF1L viruses reconstituted either with the wild-type F1L or a F1L mutant that fails to bind NLRP1. Cellular infection with wild-type F1L reconstituted virus-suppressed IL-1ß production, whereas mutant F1L did not. In contrast, both wild-type and mutant versions of F1L equally suppressed apoptosis. In vivo, the NLR nonbinding F1L mutant virus exhibited an attenuated phenotype similar to ΔF1L virus, thus confirming the importance of F1L interactions with NLRP1 for viral pathogenicity in mice. Altogether, these findings reveal a unique viral mechanism for evading host innate immune responses.
Asunto(s)
Regulación Viral de la Expresión Génica , Inmunidad Innata , Inflamasomas/metabolismo , Virus Vaccinia/metabolismo , Proteínas Virales/metabolismo , Secuencias de Aminoácidos , Animales , Caspasas/metabolismo , Chlorocebus aethiops , Citocinas/metabolismo , Células HEK293 , Células HeLa , Humanos , Interleucina-1beta/metabolismo , Ratones , Ratones Endogámicos BALB C , Mutación , Fenotipo , Proteínas Recombinantes/metabolismo , Células Vero , VirulenciaRESUMEN
Studies in mice genetically lacking natural killer T (NKT) cells show that these lymphocytes make important contributions to both innate and adaptive immune responses. However, the usefulness of murine models to study human NKT cells is limited by the many differences between mice and humans, including that their NKT cell frequencies, subsets, and distribution are dissimilar. A more suitable model may be swine that share many metabolic, physiological, and growth characteristics with humans and are also similar for NKT cells. Thus, we analyzed genetically modified pigs made deficient for CD1d that is required for the development of Type I invariant NKT (iNKT) cells that express a semi-invariant T-cell receptor (TCR) and Type II NKT cells that use variable TCRs. Peripheral blood analyzed by flow cytometry and interferon-γ enzyme-linked immuno spot assays demonstrated that CD1d-knockout pigs completely lack iNKT cells, while other leukocyte populations remain intact. CD1d and NKT cells have been shown to be involved in shaping the composition of the commensal microbiota in mice. Therefore, we also compared the fecal microbiota profile between pigs expressing and lacking NKT cells. However, no differences were found between pigs lacking or expressing CD1d. Our results are the first to show that knocking-out CD1d prevents the development of NKT cells in a non-rodent species. CD1d-deficient pigs should offer a useful model to more accurately determine the contribution of NKT cells for human immune responses. They also have potential for understanding how NKT cells impact the health of commercial swine.
Asunto(s)
Antígenos CD1d/genética , Antígenos CD1d/inmunología , Células T Asesinas Naturales/inmunología , Animales , Animales Modificados Genéticamente , Heces/microbiología , Eliminación de Gen , Células T Asesinas Naturales/metabolismo , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Análisis de Secuencia de ARN , Porcinos/genéticaRESUMEN
T cell costimulation is a key component of adaptive immunity to viral infection but has also been associated with pathology because of excessive or altered T cell activity. We recently demonstrated that the TNFR family costimulatory molecule OX40 (CD134) is critically required to sustain antiviral T cell and Ab responses that enable control of viral replication in the context of chronic lymphocytic choriomeningitis virus (LCMV) infection. In this study, we investigated whether reinforcing OX40 stimulation through an agonist Ab had the potential to prevent LCMV persistence. We observed that anti-OX40 injection early after LCMV clone 13 infection increased CD8 T cell-mediated immunopathology. More strikingly, OX40 stimulation of virus-specific CD4 T cells promoted expression of the transcriptional repressor Blimp-1 and diverted the majority of cells away from follicular Th cell differentiation. This occurred in both acute and chronic infections, and resulted in dramatic reductions in germinal center and Ab responses to the viral infection. The effect of the OX40 agonist was dependent on IL-2 signaling and the timing of OX40 stimulation. Collectively, our data demonstrate that excessive OX40 signaling can result in deleterious consequences in the setting of LCMV infection.
Asunto(s)
Linfocitos T CD4-Positivos/metabolismo , Linfocitos T CD8-positivos/inmunología , Coriomeningitis Linfocítica/inmunología , Receptores OX40/inmunología , Factores de Transcripción/biosíntesis , Animales , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Diferenciación Celular/inmunología , Chlorocebus aethiops , Centro Germinal/inmunología , Interleucina-2/metabolismo , Virus de la Coriomeningitis Linfocítica/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Factor 1 de Unión al Dominio 1 de Regulación Positiva , Receptores OX40/metabolismo , Transducción de Señal/inmunología , Células Vero , Replicación ViralRESUMEN
The human respiratory tract is an entry point for over 200 known viruses that collectively contribute to millions of annual deaths worldwide. Consequently, the World Health Organization has designated respiratory viral infections as a priority for vaccine development. Despite enormous advances in understanding the attributes of a protective mucosal antiviral immune response, current vaccines continue to fail in effectively generating long-lived protective CD8(+) T-cell immunity. To date, the majority of licensed human vaccines afford protection against infectious pathogens through the generation of specific immunoglobulin responses. In recent years, the selective manipulation of specific costimulatory pathways, which are critical in regulating T cell-mediated immune responses, has generated increasing interest. Impressive results in animal models have shown that the tumor necrosis factor receptor (TNFR) family member OX40 (CD134) and its binding partner OX40L (CD252) are key costimulatory molecules involved in the generation of protective CD8(+) T-cell responses at mucosal surfaces, such as the lung. In this review, we highlight these new findings with a particular emphasis on their potential as immunological adjuvants to enhance poxvirus-based CD8(+) T-cell vaccines.
Asunto(s)
Inmunidad Celular , Inmunidad Mucosa , Infecciones por Poxviridae , Poxviridae/inmunología , Receptores OX40/inmunología , Sistema Respiratorio/inmunología , Transducción de Señal/inmunología , Vacunas Virales , Animales , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Comunicación Celular , Expresión Génica/inmunología , Humanos , Inmunización , Memoria Inmunológica , Ratones , Ratones Noqueados , Ligando OX40/genética , Ligando OX40/inmunología , Ligando OX40/metabolismo , Poxviridae/efectos de los fármacos , Poxviridae/patogenicidad , Infecciones por Poxviridae/inmunología , Infecciones por Poxviridae/prevención & control , Infecciones por Poxviridae/virología , Receptores de Antígenos de Linfocitos T/genética , Receptores de Antígenos de Linfocitos T/inmunología , Receptores de Antígenos de Linfocitos T/metabolismo , Receptores OX40/genética , Receptores OX40/metabolismo , Receptores del Factor de Necrosis Tumoral/genética , Receptores del Factor de Necrosis Tumoral/inmunología , Receptores del Factor de Necrosis Tumoral/metabolismo , Sistema Respiratorio/citología , Sistema Respiratorio/virología , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Linfocitos T/inmunología , Linfocitos T/metabolismo , Vacunas Virales/administración & dosificaciónRESUMEN
During acute viral infections, clearance of the pathogen is followed by the contraction of the anti-viral T cell compartment. In contrast, T cell responses need to be maintained over a longer period of time during chronic viral infections in order to control viral replication and to avoid viral spreading. Much is known about inhibitory signals such as through PD-1 that limit T cell activity during chronic viral infection, but little is known about the stimulatory signals that allow maintenance of anti-viral T cells. Here, we show that the co-stimulatory molecule OX40 (CD134) is critically required in the context of persistent LCMV clone 13 infection. Anti-viral T cells express high levels of OX40 in the presence of their cognate antigen and T cells lacking the OX40 receptor fail to accumulate sufficiently. Moreover, the emergence of T cell dependent germinal center responses and LCMV-specific antibodies are severely impaired. Consequently, OX40-deficient mice fail to control LCMV clone 13 infection over time, highlighting the importance of this signaling pathway during persistent viral infection.
Asunto(s)
Inmunidad Adaptativa/genética , Receptores OX40/fisiología , Virosis/inmunología , Virosis/prevención & control , Enfermedad Aguda , Animales , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Chlorocebus aethiops , Centro Germinal/metabolismo , Centro Germinal/fisiología , Activación de Linfocitos/genética , Activación de Linfocitos/inmunología , Coriomeningitis Linfocítica/genética , Coriomeningitis Linfocítica/inmunología , Coriomeningitis Linfocítica/prevención & control , Virus de la Coriomeningitis Linfocítica/inmunología , Virus de la Coriomeningitis Linfocítica/fisiología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Receptores OX40/genética , Receptores OX40/metabolismo , Células Vero , Virosis/genética , Latencia del Virus/inmunología , Latencia del Virus/fisiologíaRESUMEN
The precise immune components required for protection against a respiratory Orthopoxvirus infection, such as human smallpox or monkeypox, remain to be fully identified. In this study, we used the virulent Western Reserve strain of vaccinia virus (VACV-WR) to model a primary respiratory Orthopoxvirus infection. Naive mice infected with VACV-WR mounted an early CD8 T cell response directed against dominant and subdominant VACV-WR Ags, followed by a CD4 T cell and Ig response. In contrast to other VACV-WR infection models that highlight the critical requirement for CD4 T cells and Ig, we found that only mice deficient in CD8 T cells presented with severe cachexia, pulmonary inflammation, viral dissemination, and 100% mortality. Depletion of CD8 T cells at specified times throughout infection highlighted that they perform their critical function between days 4 and 6 postinfection and that their protective requirement is critically dictated by initial viral load and virulence. Finally, the ability of adoptively transferred naive CD8 T cells to protect RAGâ»/â» mice against a lethal VACV-WR infection demonstrated that they are both necessary and sufficient in protecting against a primary VACV-WR infection of the respiratory tract.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/patología , Infecciones del Sistema Respiratorio/inmunología , Infecciones del Sistema Respiratorio/virología , Vaccinia/inmunología , Vaccinia/patología , Animales , Linfocitos T CD8-positivos/virología , Modelos Animales de Enfermedad , Femenino , Pulmón/inmunología , Pulmón/patología , Pulmón/virología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Mutantes , Recuperación de la Función/inmunología , Infecciones del Sistema Respiratorio/mortalidad , Índice de Severidad de la Enfermedad , Vaccinia/mortalidad , Virus Vaccinia/inmunologíaRESUMEN
Follicular Th (T(FH)) cells are specialized in provision of help to B cells that is essential for promoting protective Ab responses. CD28/B7 (B7-1 and B7-2) interactions are required for germinal center (GC) formation, but it is not clear if they simply support activation of naive CD4 T cells during initiation of responses by dendritic cells or if they directly control T(FH) cells and/or directly influence follicular B cell differentiation. Using a model of vaccinia virus infection, we show that B7-2 but not B7-1 deficiency profoundly impaired T(FH) cell development but did not affect CD4 T cell priming and Th1 differentiation. Consistent with this, B7-2 but not B7-1 was required for acquisition of GC B cell phenotype, plasma cell generation, and virus-specific neutralizing Ab responses. Mixed adoptive transfer experiments indicated that bidirectional interactions between CD28 expressed on activated T cells and B7-2 expressed on follicular B cells were essential for maintenance of the T(FH) phenotype and GC B cell development. Our data provide new insight into the source and nature of molecules required for T(FH) cells to direct GC B cell responses.