RESUMO
The use of lipid-formulated RNA vaccines for cancer or COVID-19 is associated with dose-limiting systemic inflammatory responses in humans that were not predicted from preclinical studies. Here, we show that the 'interleukin 1 (IL-1)-interleukin 1 receptor antagonist (IL-1ra)' axis regulates vaccine-mediated systemic inflammation in a host-specific manner. In human immune cells, RNA vaccines induce production of IL-1 cytokines, predominantly IL-1ß, which is dependent on both the RNA and lipid formulation. IL-1 in turn triggers the induction of the broad spectrum of pro-inflammatory cytokines (including IL-6). Unlike humans, murine leukocytes respond to RNA vaccines by upregulating anti-inflammatory IL-1ra relative to IL-1 (predominantly IL-1α), protecting mice from cytokine-mediated toxicities at >1,000-fold higher vaccine doses. Thus, the IL-1 pathway plays a key role in triggering RNA vaccine-associated innate signaling, an effect that was unexpectedly amplified by certain lipids used in vaccine formulations incorporating N1-methyl-pseudouridine-modified RNA to reduce activation of Toll-like receptor signaling.
Assuntos
Inflamação , Proteína Antagonista do Receptor de Interleucina 1 , Interleucina-1 , Animais , COVID-19 , Inflamação/imunologia , Inflamação/metabolismo , Proteína Antagonista do Receptor de Interleucina 1/genética , Proteína Antagonista do Receptor de Interleucina 1/imunologia , Interleucina-1/genética , Interleucina-1/imunologia , Lipídeos , Camundongos , RNA , Vacinas Sintéticas , Vacinas de mRNA/efeitos adversos , Vacinas de mRNA/metabolismoRESUMO
Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disease representing a serious unmet medical need. The disease is associated with the loss of self-tolerance and exaggerated B cell activation, resulting in autoantibody production and the formation of immune complexes that accumulate in the kidney, causing glomerulonephritis. TLR7, an important mediator of the innate immune response, drives the expression of type-1 interferon (IFN), which leads to expression of type-1 IFN induced genes and aggravates lupus pathology. Because the lysosomal peptide symporter slc15a4 is critically required for type-1 interferon production by pDC, and for certain B cell functions in response to TLR7 and TLR9 signals, we considered it as a potential target for pharmacological intervention in SLE. We deleted the slc15a4 gene in C57BL/6, NZB, and NZW mice and found that pristane-challenged slc15a4-/- mice in the C57BL/6 background and lupus prone slc15a4-/- NZB/W F1 mice were both completely protected from lupus like disease. In the NZB/W F1 model, protection persisted even when disease development was accelerated with an adenovirus encoding IFNα, emphasizing a broad role of slc15a4 in disease initiation. Our results establish a non-redundant function of slc15a4 in regulating both innate and adaptive components of the immune response in SLE pathobiology and suggest that it may be an attractive drug target.
Assuntos
Lúpus Eritematoso Sistêmico/patologia , Proteínas de Membrana Transportadoras/metabolismo , Animais , Quimiocinas/metabolismo , Citocinas/metabolismo , Células Dendríticas/citologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Imidazóis/farmacologia , Interferon-alfa/genética , Interferon-alfa/metabolismo , Interferon-alfa/farmacologia , Lúpus Eritematoso Sistêmico/metabolismo , Lúpus Eritematoso Sistêmico/mortalidade , Proteínas de Membrana Transportadoras/deficiência , Proteínas de Membrana Transportadoras/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NZB , Camundongos Knockout , Taxa de Sobrevida , Terpenos/farmacologia , Receptor 7 Toll-Like/agonistas , Receptor 7 Toll-Like/metabolismo , Receptor Toll-Like 9/metabolismoRESUMO
Tumor progression locus 2 (TPL2; also known as MAP3K8) is a mitogen-activated protein kinase (MAPK) kinase kinase (MAP3K) that phosphorylates the MAPK kinases MEK1 and MEK2 (MEK1/2), which, in turn, activate the MAPKs extracellular signal-regulated kinase 1 (ERK1) and ERK2 (ERK1/2) in macrophages stimulated through the interleukin-1 receptor (IL-1R), Toll-like receptors (TLRs), or the tumor necrosis factor receptor (TNFR). We describe a conserved and critical role for TPL2 in mediating the effector functions of neutrophils through the activation of the p38 MAPK signaling pathway. Gene expression profiling and functional studies of neutrophils and monocytes revealed a MEK1/2-independent branch point downstream of TPL2 in neutrophils. Biochemical analyses identified the MAPK kinases MEK3 and MEK6 and the MAPKs p38α and p38δ as downstream effectors of TPL2 in these cells. Genetic ablation of the catalytic activity of TPL2 or therapeutic intervention with a TPL2-specific inhibitor reduced the production of inflammatory mediators by neutrophils in response to stimulation with the TLR4 agonist lipopolysaccharide (LPS) in vitro, as well as in rodent models of inflammatory disease. Together, these data suggest that TPL2 is a drug target that activates not only MEK1/2-dependent but also MEK3/6-dependent signaling to promote inflammatory responses.
Assuntos
MAP Quinase Quinase Quinases/metabolismo , Sistema de Sinalização das MAP Quinases , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Ativação de Neutrófilo , Neutrófilos/enzimologia , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Ativação Enzimática , Inflamação/enzimologia , Inflamação/genética , MAP Quinase Quinase 3/genética , MAP Quinase Quinase 3/metabolismo , MAP Quinase Quinase 6/genética , MAP Quinase Quinase 6/metabolismo , MAP Quinase Quinase Quinases/genética , Camundongos , Proteína Quinase 3 Ativada por Mitógeno/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Quinases p38 Ativadas por Mitógeno/genéticaRESUMO
Toll-like receptors (TLRs) enable metazoans to mount effective innate immune responses to microbial and viral pathogens, as well as to endogenous host-derived ligands. It is understood that genetic background of the host can influence TLR responsiveness, altering susceptibility to pathogen infection, autoimmunity and cancer. Macrophage stimulatory protein (MSP), which activates the receptor tyrosine kinase recepteur d'origine nantais (RON), promotes key macrophage functions such as motility and phagocytic activity. MSP also acts via RON to modulate signaling by TLR4, which recognizes a range of pathogen or endogenous host-derived molecules. Here, we show that RON exerts divergent control over TLR4 activity in macrophages from different mouse genetic backgrounds. RON potently modulated the TLR4 response in macrophages from M2-prone FVB mice, as compared with M1-skewed C57Bl6 mice. Moreover, global expression analysis revealed that RON suppresses the TLR4-dependent type-I interferon gene signature only in FVB macrophages. This leads to attenuated production of the potent inflammatory mediator, tumor necrosis factor-α. Eliminating RON kinase activity markedly decreased carcinogen-mediated tumorigenesis in M2/Th2-biased FVB mice. We propose that host genetic background influences RON function, thereby contributing to the variability in TLR4 responsiveness in rodents and, potentially, in humans. These findings provide novel insight into the complex interplay between genetic context and immune function.
Assuntos
Fibrossarcoma/imunologia , Macrófagos Peritoneais/imunologia , Papiloma/imunologia , Receptores Proteína Tirosina Quinases/metabolismo , Neoplasias Cutâneas/imunologia , Receptor 4 Toll-Like/imunologia , 9,10-Dimetil-1,2-benzantraceno/administração & dosagem , Animais , Carcinogênese , Movimento Celular/efeitos dos fármacos , Fibrossarcoma/induzido quimicamente , Fibrossarcoma/genética , Genótipo , Fator de Crescimento de Hepatócito/metabolismo , Interferon Tipo I/genética , Interferon Tipo I/metabolismo , Metilcolantreno/administração & dosagem , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Papiloma/induzido quimicamente , Papiloma/genética , Proteínas Proto-Oncogênicas/metabolismo , Receptores Proteína Tirosina Quinases/genética , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/genética , Equilíbrio Th1-Th2 , Ativação Transcricional/genética , TranscriptomaRESUMO
SecA2 is an ATPase present in some pathogenic Gram-positive bacteria, is required for translocation of a limited set of proteins across the cytosolic membrane, and plays an important role in virulence in several bacteria, including mycobacteria that cause diseases such as tuberculosis and leprosy. However, the mechanisms by which SecA2 affects virulence are incompletely understood. To investigate whether SecA2 modulates host immune responses in vivo, we studied Mycobacterium marinum infection in two different hosts: an established zebrafish model and a recently described mouse model. Here we show that M. marinum ΔsecA2 was attenuated for virulence in both host species and SecA2 was needed for normal granuloma numbers and for optimal tumor necrosis factor alpha response in both zebrafish and mice. M. marinum ΔsecA2 was more sensitive to SDS and had unique protrusions from its cell envelope when examined by cryo-electron tomography, suggesting that SecA2 is important for bacterial cell wall integrity. These results provide evidence that SecA2 induces granulomas and is required for bacterial modulation of the host response because it affects the mycobacterial cell envelope.
Assuntos
Adenosina Trifosfatases/metabolismo , Proteínas de Bactérias/metabolismo , Granuloma/microbiologia , Proteínas de Membrana Transportadoras/metabolismo , Infecções por Mycobacterium não Tuberculosas/microbiologia , Mycobacterium marinum/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Adenosina Trifosfatases/genética , Animais , Proteínas de Bactérias/genética , Células Cultivadas , Feminino , Humanos , Inflamação/metabolismo , Macrófagos , Proteínas de Membrana Transportadoras/genética , Camundongos , Camundongos Endogâmicos C57BL , Infecções por Mycobacterium não Tuberculosas/imunologia , Infecções por Mycobacterium não Tuberculosas/metabolismo , Mycobacterium marinum/genética , Mycobacterium marinum/patogenicidade , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Necrose Tumoral alfa/genética , Virulência , Peixe-ZebraRESUMO
Uncontrolled T helper type 1 (T(H)1) and T(H)17 cells are associated with autoimmune responses. We identify surface lymphotoxin-alpha (LT-alpha) as common to T(H)0, T(H)1 and T(H)17 cells and employ a unique strategy to target these subsets using a depleting monoclonal antibody (mAb) directed to surface LT-alpha. Depleting LT-alpha-specific mAb inhibited T cell-mediated models of delayed-type hypersensitivity and experimental autoimmune encephalomyelitis. In collagen-induced arthritis (CIA), preventive and therapeutic administration of LT-alpha-specific mAb inhibited disease, and immunoablated T cells expressing interleukin-17 (IL-17), interferon-gamma and tumor necrosis factor-alpha (TNF-alpha), whereas decoy lymphotoxin-beta receptor (LT-betaR) fusion protein had no effect. A mutation in the Fc tail, rendering the antibody incapable of Fcgamma receptor binding and antibody-dependent cellular cytotoxicity activity, abolished all in vivo effects. Efficacy in CIA was preceded by a loss of rheumatoid-associated cytokines IL-6, IL-1beta and TNF-alpha within joints. These data indicate that depleting LT-alpha-expressing lymphocytes with LT-alpha-specific mAb may be beneficial in the treatment of autoimmune disease.
Assuntos
Doenças Autoimunes/terapia , Interleucina-17/fisiologia , Depleção Linfocítica , Linfotoxina-alfa/antagonistas & inibidores , Células Th1/imunologia , Animais , Anticorpos Monoclonais/uso terapêutico , Artrite Experimental/terapia , Doenças Autoimunes/etiologia , Doenças Autoimunes/imunologia , Inflamação/etiologia , Camundongos , Camundongos Endogâmicos DBARESUMO
Approximately two billion people, mainly women and children, are iron deficient. Two studies examined the effects of iron deficiency and supplementation on rats. In study 1, mitochondrial functional parameters and mitochondrial DNA (mtDNA) damage were assayed in iron-deficient (< or =5 microg/day) and iron-normal (800 microg/day) rats and in both groups after daily high-iron supplementation (8,000 microg/day) for 34 days. This dose is equivalent to the daily dose commonly given to iron-deficient humans. Iron-deficient rats had lower liver mitochondrial respiratory control ratios and increased levels of oxidants in polymorphonuclear-leukocytes, as assayed by dichlorofluorescein (P < 0.05). Rhodamine 123 fluorescence of polymorphonuclear-leukocytes also increased (P < 0.05). Lowered respiratory control ratios were found in daily high-iron-supplemented rats regardless of the previous iron status (P < 0.05). mtDNA damage was observed in both iron-deficient rats and rats receiving daily high-iron supplementation, compared with iron-normal rats (P < 0.05). Study 2 compared iron-deficient rats given high doses of iron (8,000 microg) either daily or every third day and found that rats given iron supplements every third day had less mtDNA damage on the second and third day after the last dose compared to daily high iron doses. Both inadequate and excessive iron (10 x nutritional need) cause significant mitochondrial malfunction. Although excess iron has been known to cause oxidative damage, the observation of oxidant-induced damage to mitochondria from iron deficiency has been unrecognized previously. Untreated iron deficiency, as well as excessive-iron supplementation, are deleterious and emphasize the importance of maintaining optimal iron intake.