RESUMO
The involvement of secreted phospholipase A2s in respiratory diseases, such as asthma and respiratory viral infections, is well-established. However, the specific role of secreted phospholipase A2 group IIE (PLA2G2E) during influenza virus infection remains unexplored. Here, we investigated the role of PLA2G2E during H1N1 influenza virus infection using a targeted mouse model lacking Pla2g2e gene (Pla2g2e-/-). Our findings demonstrated that Pla2g2e-/- mice had significantly lower survival rates and higher viral loads in lungs compared to wild-type mice following influenza virus infection. While Pla2g2e-/- mice displayed comparable innate and humoral immune responses to influenza virus challenge, the animals showed impaired influenza-specific cellular immunity and reduced T cell-mediated cytotoxicity. This indicates that PLA2G2E is involved in regulating specific T cell responses during influenza virus infection. Furthermore, transgenic mice expressing the human PLA2G2E gene exhibited resistance to influenza virus infection along with enhanced influenza-specific cellular immunity and T cell-mediated cytotoxicity. Pla2g2e deficiency resulted in perturbation of lipid mediators in the lung and T cells, potentially contributing to its impact on the anti-influenza immune response. Taken together, these findings suggest that targeting PLA2G2E could hold potential as a therapeutic strategy for managing influenza virus infections.IMPORTANCEThe influenza virus is a highly transmissible respiratory pathogen that continues to pose a significant public health concern. It effectively evades humoral immune protection conferred by vaccines and natural infection due to its continuous viral evolution through the genetic processes of antigenic drift and shift. Recognition of conserved non-mutable viral epitopes by T cells may provide broad immunity against influenza virus. In this study, we have demonstrated that phospholipase A2 group IIE (PLA2G2E) plays a crucial role in protecting against influenza virus infection through the regulation of T cell responses, while not affecting innate and humoral immune responses. Targeting PLA2G2E could therefore represent a potential therapeutic strategy for managing influenza virus infection.
Assuntos
Vírus da Influenza A Subtipo H1N1 , Pulmão , Infecções por Orthomyxoviridae , Animais , Camundongos , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia , Vírus da Influenza A Subtipo H1N1/imunologia , Pulmão/virologia , Pulmão/imunologia , Pulmão/patologia , Humanos , Fosfolipases A2 do Grupo II/genética , Fosfolipases A2 do Grupo II/imunologia , Linfócitos T/imunologia , Camundongos Knockout , Imunidade Celular , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Carga Viral , Modelos Animais de Doenças , Imunidade Humoral , Imunidade Inata , Influenza Humana/imunologia , Influenza Humana/virologia , FemininoRESUMO
Secreted phospholipase A2s are involved in the development of obesity, type 2 diabetes mellitus (T2DM) and cardiovascular disease, which have become serious and growing health concerns worldwide. Integration of genome-wide association study and gene co-expression networks analysis showed that the secreted phospholipase A2 group XIIA (PLA2G12A) may participate in hepatic lipids metabolism. Nevertheless, the role of PLA2G12A in lipid metabolism and its potential mechanism remain elusive. Here, we used AAV9 vector carrying human PLA2G12A gene to exogenously express hPLA2G12A in the liver of mice. We demonstrated that the overexpression of hPLA2G12A resulted in a significant decrease in serum lipid levels in wild-type mice fed with chow diet or high-fat diet (HFD). Moreover, hPLA2G12A treatment protected against diet-induced obesity and insulin resistance in mice fed a HFD. Notably, we found that hPLA2G12A treatment confers protection against obesity and hyperlipidemia independent of its enzymatic activity, but rather by increasing physical activity and energy expenditure. Furthermore, we demonstrated that hPLA2G12A treatment induced upregulation of ApoC2 and Cd36 and downregulation of Angptl8, which contributed to the increase in clearance of circulating triglycerides and hepatic uptake of fatty acids without affecting hepatic de novo lipogenesis, very low-density lipoprotein secretion, or intestinal lipid absorption. Our study highlights the potential of PLA2G12A gene therapy as a promising approach for treating obesity, insulin resistance and T2DM.
Assuntos
Dieta Hiperlipídica , Metabolismo Energético , Resistência à Insulina , Camundongos Endogâmicos C57BL , Obesidade , Triglicerídeos , Animais , Obesidade/metabolismo , Obesidade/etiologia , Camundongos , Triglicerídeos/metabolismo , Triglicerídeos/sangue , Masculino , Dieta Hiperlipídica/efeitos adversos , Humanos , Fígado/metabolismo , Metabolismo dos LipídeosRESUMO
The persistence of cells latently infected with HIV-1, named the latent reservoir, is the major barrier to HIV-1 eradication, and the formation and maintenance of the latent reservoir might be exacerbated by activation of the immunoinhibitory pathway and dysfunction of CD8+ T cells during HIV-1 infection. Our previous findings demonstrated that prophylactic vaccination combined with PD-1 blockade generated distinct immune response profiles and conferred effective control of highly pathogenic SIVmac239 infection in rhesus macaques. However, to our surprise, herein we found that a therapeutic vaccination in combination with PD-1 blockade resulted in activation of the viral reservoir, faster viral rebound after treatment interruption, accelerated AIDS progression, and, ultimately, death in chronically SIV-infected macaques after antiretroviral therapy (ART) interruption. Our study further demonstrated that the SIV provirus was preferentially enriched in PD-1+CD4+ T cells due to their susceptibility to viral entry, potent proliferative ability, and inability to perform viral transcription. In addition, the viral latency was effectively reactivated upon PD-1 blockade. Together, these results suggest that PD-1 blockade may be a double-edged sword for HIV-1 immunotherapy and provide important insight toward the rational design of immunotherapy strategies for an HIV-1 cure. IMPORTANCE As it is one of the most challenging public health problems, there are no clinically effective cure strategies against HIV-1 infection. We demonstrated that prophylactic vaccination combined with PD-1 blockade generated distinct immune response profiles and conferred better control of highly pathogenic SIVmac239 infection in rhesus macaques. In the present study, to our surprise, PD-1 blockade during therapeutic vaccination accelerated the reactivation of latent reservoir and AIDS progression in chronically SIV-infected macaques after ART interruption. Our study further demonstrated that the latent SIV provirus was preferentially enriched in PD-1+CD4+ T cells because of its susceptibility to viral entry, inhibition of SIV transcription, and potent ability of proliferation, and the viral latency was effectively reactivated by PD-1 blockade. Therefore, PD-1 blockade might be a double-edged sword for AIDS therapy. These findings provoke interest in further exploring novel treatments against HIV-1 infection and other emerging infectious diseases.
Assuntos
Receptor de Morte Celular Programada 1/antagonistas & inibidores , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/efeitos dos fármacos , Vírus da Imunodeficiência Símia/imunologia , Animais , Antirretrovirais/farmacologia , Antirretrovirais/uso terapêutico , Terapia Antirretroviral de Alta Atividade , Biópsia , Biologia Computacional , Progressão da Doença , Imuno-Histoquímica , Imunomodulação/efeitos dos fármacos , Macaca mulatta , Vacinas contra a SAIDS/administração & dosagem , Vacinas contra a SAIDS/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/tratamento farmacológico , Subpopulações de Linfócitos T/efeitos dos fármacos , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Transcriptoma , Carga Viral , Ativação Viral/efeitos dos fármacos , Latência Viral/efeitos dos fármacos , Replicação Viral/efeitos dos fármacosRESUMO
A comprehensive study of the B cell response against SARS-CoV-2 could be significant for understanding the immune response and developing therapeutical antibodies and vaccines. To define the dynamics and characteristics of the antibody repertoire following SARS-CoV-2 infection, we analyzed the mRNA transcripts of immunoglobulin heavy chain (IgH) repertoires of 24 peripheral blood samples collected between 3 and 111 days after symptom onset from 10 COVID-19 patients. Massive clonal expansion of naive B cells with limited somatic hypermutation (SHM) was observed in the second week after symptom onset. The proportion of low-SHM IgG clones strongly correlated with spike-specific IgG antibody titers, highlighting the significant activation of naive B cells in response to a novel virus infection. The antibody isotype switching landscape showed a transient IgA surge in the first week after symptom onset, followed by a sustained IgG elevation that lasted for at least 3 months. SARS-CoV-2 infection elicited poly-germ line reactive antibody responses. Interestingly, 17 different IGHV germ line genes recombined with IGHJ6 showed significant clonal expansion. By comparing the IgH repertoires that we sequenced with the 774 reported SARS-CoV-2-reactive monoclonal antibodies (MAbs), 13 shared spike-specific IgH clusters were found. These shared spike-specific IgH clusters are derived from the same lineage of several recently published neutralizing MAbs, including CC12.1, CC12.3, C102, REGN10977, and 4A8. Furthermore, identical spike-specific IgH sequences were found in different COVID-19 patients, suggesting a highly convergent antibody response to SARS-CoV-2. Our analysis based on sequencing antibody repertoires from different individuals revealed key signatures of the systemic B cell response induced by SARS-CoV-2 infection. IMPORTANCE Although the canonical delineation of serum antibody responses following SARS-CoV-2 infection has been well established, the dynamics of antibody repertoire at the mRNA transcriptional level has not been well understood, especially the correlation between serum antibody titers and the antibody mRNA transcripts. In this study, we analyzed the IgH transcripts and characterized the B cell clonal expansion and differentiation, isotype switching, and somatic hypermutation in COVID-19 patients. This study provided insights at the repertoire level for the B cell response after SARS-CoV-2 infection.
Assuntos
Anticorpos Neutralizantes/genética , Anticorpos Antivirais/genética , Linfócitos B/imunologia , COVID-19/genética , Imunoglobulina G/genética , Receptores de Antígenos de Linfócitos B/genética , SARS-CoV-2/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/imunologia , Humanos , Imunoglobulina G/imunologia , Receptores de Antígenos de Linfócitos B/imunologiaRESUMO
Coronavirus disease 2019 (COVID-19) is caused by a novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with some patients developing severe illness or even death. Disease severity has been associated with increased levels of proinflammatory cytokines and lymphopenia. To elucidate the atlas of peripheral immune response and pathways that might lead to immunopathology during COVID-19 disease course, we performed a peripheral blood RNA sequencing analysis of the same patient's samples collected from symptom onset to full recovery. We found that PBMCs at different disease stages exhibited unique transcriptome characteristics. We observed that SARS-CoV-2 infection caused excessive release of inflammatory cytokines and lipid mediators as well as an aberrant increase of low-density neutrophils. Further analysis revealed an increased expression of RNA sensors and robust IFN-stimulated genes expression but a repressed type I IFN production. SARS-CoV-2 infection activated T and B cell responses during the early onset but resulted in transient adaptive immunosuppression during severe disease state. Activation of apoptotic pathways and functional exhaustion may contribute to the reduction of lymphocytes and dysfunction of adaptive immunity, whereas increase in IL2, IL7, and IL15 may facilitate the recovery of the number and function of lymphocytes. Our study provides comprehensive transcriptional signatures of peripheral blood response in patients with moderate COVID-19.
Assuntos
COVID-19/sangue , Citocinas/sangue , Progressão da Doença , Mediadores da Inflamação/sangue , Leucócitos Mononucleares/metabolismo , RNA-Seq , SARS-CoV-2/metabolismo , Adulto , Idoso , Feminino , Regulação da Expressão Gênica , Humanos , Leucócitos Mononucleares/virologia , Estudos Longitudinais , Masculino , Pessoa de Meia-IdadeRESUMO
Recombinant influenza A viral (IAV) vectors are potential to stimulate systemic and mucosal immunity, but the packaging capacity is limited and only one or a few epitopes can be carried. Here, we report the generation of a replication-competent IAV vector that carries a full-length HIV-1 p24 gene linked to the 5'-terminal coding region of the neuraminidase segment via a protease cleavage sequence (IAV-p24). IAV-p24 was successfully rescued and stably propagated, and P24 protein was efficiently expressed in infected mammalian cells. In BALB/c mice, IAV-p24 showed attenuated pathogenicity compared to that of the parental A/PR/8/34 (H1N1) virus. An intranasal inoculation with IAV-p24 elicited moderate HIV-specific cell-mediated immune (CMI) responses in the airway and vaginal tracts and in the spleen, and an intranasal boost with a replication-incompetent adenovirus type 2 vector expressing the HIV-1 gag gene (Ad2-gag) greatly improved these responses. Importantly, compared to an Ad2-gag prime plus IAV-p24 boost regimen, the IAV-p24 prime plus Ad2-gag boost regimen had a greater efficacy in eliciting HIV-specific CMI responses. P24-specific CD8+ T cells and antibodies were robustly provoked both systemically and in mucosal sites and showed long-term durability, revealing that IAV-p24 may be used as a mucosa-targeted priming vaccine. Our results illustrate that IAV-p24 is able to prime systemic and mucosal immunity against HIV-1 and warrants further evaluation in nonhuman primates.IMPORTANCE An effective HIV-1 vaccine remains elusive despite nearly 40 years of research. CD8+ T cells and protective antibodies may both be desirable for preventing HIV-1 infection in susceptible mucosal sites. Recombinant influenza A virus (IAV) vector has the potential to stimulate these immune responses, but the packaging capacity is extremely limited. Here, we describe a replication-competent IAV vector expressing the HIV-1 p24 gene (IAV-p24). Unlike most other IAV vectors that carried one or several antigenic epitopes, IAV-p24 stably expressed the full-length P24 protein, which contains multiple epitopes and is highly conserved among all known HIV-1 sequences. Compared to the parental A/PR/8/34 (H1N1) virus, IAV-p24 showed an attenuated pathogenicity in BALB/c mice. When combined with an adenovirus vector expressing the HIV-1 gag gene, IAV-p24 was able to prime P24-specific systemic and mucosal immune responses. IAV-p24 as an alternative priming vaccine against HIV-1 warrants further evaluation in nonhuman primates.
Assuntos
Vacinas contra a AIDS/imunologia , Linfócitos T CD8-Positivos/imunologia , Anticorpos Anti-HIV/análise , Proteína do Núcleo p24 do HIV/imunologia , HIV-1/imunologia , Imunidade nas Mucosas , Adenoviridae/genética , Animais , Anticorpos Antivirais/sangue , Líquido da Lavagem Broncoalveolar/imunologia , Feminino , Genes gag , Anticorpos Anti-HIV/sangue , Proteína do Núcleo p24 do HIV/genética , Infecções por HIV/prevenção & controle , Imunidade Celular , Imunização Secundária , Imunogenicidade da Vacina , Imunoglobulina A/análise , Imunoglobulina A/sangue , Imunoglobulina G/análise , Imunoglobulina G/sangue , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/patogenicidade , Vírus da Influenza A Subtipo H3N2/imunologia , Tecido Linfoide/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Vacinação , Vacinas Sintéticas/imunologiaRESUMO
Scavenger receptors play a central role in defending against infectious diseases in mammals. However, the function of SRECII remains unknown in teleost fish. In this study, type F scavenger receptor expressed by endothelial cells-II (SRECII) cDNA sequence was first identified from Epinephelus coioides, named EcSRECII, which contained an N-terminal signal peptide, eight EGF/EGF-like cysteine-rich motifs and a C-terminal low-complexity region. The gene location maps revealed that EcSRECII has the conservation of synteny among selected species. Subcellular localization showed that EcSRECII was mainly located in the cytoplasm in HEK293T cells and GS cells. In healthy E. coioides, EcSRECII mRNA was highly expressed in spleen, skin, gill, thymus and head kidney. The relative EcSRECII mRNA expression after Vibrio parahaemolyticus infection was significantly up-regulated at 12 h in spleen, head kidney and thymus, but downregulated at 1 d in skin and reduced at 3 d and 1 w in spleen. Furthermore, overexpression of EcSRECII activated NF-κB and IFN-ß signaling pathway in vitro. Taken together, these results indicated that EcSRECII could be as the potential pathogen recognition receptor for involving in bacterial infection by regulating innate immunity responses in E. coioides.
Assuntos
Bass/microbiologia , Células Endoteliais/metabolismo , Proteínas de Peixes/metabolismo , Receptores Depuradores Classe F/metabolismo , Vibrio parahaemolyticus/fisiologia , Animais , Bass/imunologia , Proteínas de Peixes/genética , Células HEK293 , Humanos , Interferon beta/genética , Interferon beta/metabolismo , NF-kappa B/genética , NF-kappa B/metabolismo , Filogenia , Domínios Proteicos , Receptores Depuradores Classe F/genética , Transdução de Sinais/imunologia , Sintenia , Distribuição Tecidual , Ativação TranscricionalRESUMO
The continuous emergence of highly immune-evasive SARS-CoV-2 variants has challenged vaccine efficacy. A vaccine that can provide broad protection is desirable. We evaluated the immunogenicity of a series of monovalent and bivalent adenovirus-vectored vaccines containing the spikes of Wildtype (WT), Beta, Delta, Omicron subvariants BA.1, BA.2, BA.2.12.1, BA.2.13, BA.3, BA.5, BQ.1.1, and XBB. Vaccination in mice using monovalent vaccines elicited the highest neutralizing titers against each self-matched strain, but against other variants were reduced 2- to 73-fold. A bivalent vaccine consisting of WT and BA.5 broadened the neutralizing breadth against pre-Omicron and Omicron subvariants except XBB. Among bivalent vaccines based on the strains before the emergence of XBB, a bivalent vaccine consisting of BA.2 and BA.5 elicited the most potent neutralizing antibodies against Omicron subvariants, including XBB. In mice primed with injected WT vaccine, intranasal booster with a bivalent vaccine containing XBB and BA.5 could elicit broad serum and respiratory mucosal neutralizing antibodies against all late Omicron subvariants, including XBB. In mice that had been sequentially vaccinated with WT and BA.5, intranasal booster with a monovalent XBB vaccine elicited greater serum and mucosal XBB neutralizing antibodies than bivalent vaccines containing XBB. Both monovalent and bivalent XBB vaccines induced neutralizing antibodies against EG.5. Unlike the antibody response, which is highly variant-specific, mice receiving either monovalent or bivalent vaccines elicited comparable T-cell responses against all variants. Furthermore, intranasal but not intramuscular booster induced antigen-specific lung resident T cells. This study provides insights into the design of the COVID-19 vaccine and vaccination strategies.
Assuntos
Vacinas contra Adenovirus , Anticorpos Neutralizantes , Anticorpos Antivirais , Vacinas contra COVID-19 , COVID-19 , Camundongos Endogâmicos BALB C , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Animais , SARS-CoV-2/imunologia , SARS-CoV-2/genética , Camundongos , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , COVID-19/prevenção & controle , COVID-19/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Vacinas contra Adenovirus/imunologia , Vacinas contra Adenovirus/administração & dosagem , Feminino , Humanos , Imunogenicidade da Vacina , Vacinação , Adenoviridae/genética , Adenoviridae/imunologiaRESUMO
Neutralizing antibodies are a key component in protective humoral immunity against SARS-CoV-2. Currently, available technologies cannot track epitope-specific antibodies in global antibody repertoires. Thus, the comprehensive repertoire of spike-specific neutralizing antibodies elicited by SARS-CoV-2 infection is not fully understood. We therefore combined high-throughput immunoglobulin heavy chain (IgH) repertoire sequencing, and structural and bioinformatics analysis to establish an antibodyomics pipeline, which enables tracking spike-specific antibody lineages that target certain neutralizing epitopes. We mapped the neutralizing epitopes on the spike and determined the epitope-preferential antibody lineages. This analysis also revealed numerous overlaps between immunodominant neutralizing antibody-binding sites and mutation hotspots on spikes as observed so far in SARS-CoV-2 variants. By clustering 2677 spike-specific antibodies with 360 million IgH sequences that we sequenced, a total of 329 shared spike-specific antibody clonotypes were identified from 33 COVID-19 convalescents and 24 SARS-CoV-2-naïve individuals. Epitope mapping showed that the shared antibody responses target not only neutralizing epitopes on RBD and NTD but also non-neutralizing epitopes on S2. The immunodominance of neutralizing antibody response is determined by the occurrence of specific precursors in human naïve B-cell repertoires. We identified that only 28 out of the 329 shared spike-specific antibody clonotypes persisted for at least 12 months. Among them, long-lived IGHV3-53 antibodies are likely to evolve cross-reactivity to Omicron variants through accumulating somatic hypermutations. Altogether, we created a comprehensive atlas of spike-targeting antibody lineages in COVID-19 convalescents and antibody precursors in human naïve B cell repertoires, providing a valuable reference for future vaccine design and evaluation.
Assuntos
Ascomicetos , COVID-19 , Humanos , SARS-CoV-2/genética , Anticorpos Neutralizantes , Epitopos , Anticorpos Antivirais , Glicoproteína da Espícula de Coronavírus/genéticaRESUMO
The upper respiratory tract is the initial site of SARS-CoV-2 infection. Nasal spike-specific secretory immunoglobulin A (sIgA) correlates with protection against Omicron breakthrough infection. We report that intranasal vaccination using human adenovirus serotype 5 (Ad5) vectored Omicron spike in people who previously vaccinated with ancestral vaccine could induce robust neutralizing sIgA in the nasal passage. Nasal sIgA was predominantly present in dimeric and multimeric forms and accounted for nearly 40% of total proteins in nasal mucosal lining fluids (NMLFs). A low-level IgG could also be detected in NMLFs but not IgM, IgD, and IgE. After a complete nasal wash, sIgA in the nasal passage could be replenished rapidly within a few hours. A comparison of purified paired serum IgA, serum IgG, and nasal sIgA from the same individuals showed that sIgA was up to 3-logs more potent than serum antibodies in binding to spikes and in neutralizing Omicron subvariants. Serum IgG and IgA failed to neutralize XBB and BA.2.86, while nasal sIgA retained potent neutralization against these newly emerged variants. Further analysis showed that sIgA was more effective than IgG or IgA in blocking spike-mediated cell-to-cell transmission and protecting hACE2 mice from XBB challenge. Using a sIgA monoclonal antibody as a reference, we estimated that the total nasal sIgA contains about 2.6-3.9% spike-specific sIgA in NMLFs collected approximately one month after intranasal vaccination. Our study provided insights for developing intranasal vaccines that can induce sIgA to build an effective and mutation-resistant first-line immune barrier against constantly emerging variants.
Assuntos
Administração Intranasal , Anticorpos Neutralizantes , Anticorpos Antivirais , Vacinas contra COVID-19 , COVID-19 , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Humanos , SARS-CoV-2/imunologia , SARS-CoV-2/genética , COVID-19/prevenção & controle , COVID-19/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/sangue , Animais , Camundongos , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/sangue , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/genética , Vacinas contra COVID-19/administração & dosagem , Imunoglobulina A/imunologia , Imunoglobulina A/sangue , Imunoglobulina A/genética , Mucosa Nasal/imunologia , Mucosa Nasal/virologia , Feminino , Vetores Genéticos/imunologia , Vetores Genéticos/genética , Enzima de Conversão de Angiotensina 2/genética , Enzima de Conversão de Angiotensina 2/imunologia , Imunoglobulina A Secretora/imunologia , Adenoviridae/genética , Adenoviridae/imunologia , Imunoglobulina G/imunologia , Imunoglobulina G/sangue , MasculinoRESUMO
Background: Influenza virus infection complicated by secondary bacterial pneumonia contributes significantly to death during seasonal or pandemic influenza. Secondary infection of Pseudomonas aeruginosa (P. aeruginosa) in influenza virus-infected patients contributes to morbidity and mortality. Methods: Mice were first infected with PR8 influenza virus, followed by a secondary infection of P. aeruginosa. Body weights and survival rate of mice was monitored daily over 20 days. Bronchoalveolar lavage fluids (BALFs) and lung homogenates were harvested for measuring bacterial titers. Lung tissue section slides were stained with hematoxylin and eosin for microscopic observation. After vaccination with inactivated P. aeruginosa cells or recombinant PcrV protein, the mice were subjected to PR8 influenza virus infection followed by a secondary infection of a P. aeruginosa. The inhibition against P. aeruginosa of serum was evaluated by detecting the growth of P. aeruginosa in broth containing diluted sera. Results: The prior influenza infection greatly enhanced the susceptibility to secondary infection of P. aeruginosa and increased morbidity and mortality in mice. Active immunization with inactivated P. aeruginosa cells could protect mice from secondary P. aeruginosa challenge in influenza virus infected mice. Conclusions: To develop an effective P. aeruginosa vaccine might be a promising strategy to decrease the threat of secondary P. aeruginosa infection in influenza patients.
RESUMO
African swine fever (ASF) is an acute and highly contagious lethal infectious disease in swine that severely threatens the global pig industry. At present, a safe and efficacious vaccine is urgently required to prevent and control the disease. In this study, we evaluated the safety and immunogenicity of replication-incompetent type-2 adenoviruses carrying African swine fever virus (ASFV) antigens, namely CP204L (p30), E183L (p54), EP402R (CD2v), B646L (p72), and B602L (p72 chaperone). A vaccine cocktail delivered by simultaneous intramuscular (IM) and intranasal (IN) administration robustly elicited both systemic and mucosal immune responses against AFSV in mice and swine and provided highly effective protection against the circulating ASFV strain in farmed pigs. This multi-antigen cocktail vaccine was well tolerated in the vaccinated animals. No significant interference among antigens was observed. The combined IM and IN vaccination using this adenovirus-vectored antigen cocktail vaccine warrants further evaluation for providing safe and effective protection against ASFV infection and transmission.
Assuntos
Infecções por Adenoviridae , Vacinas contra Adenovirus , Vírus da Febre Suína Africana , Febre Suína Africana , Vacinas Virais , Suínos , Animais , Camundongos , Vírus da Febre Suína Africana/genética , Febre Suína Africana/prevenção & controle , Adenoviridae/genética , Antígenos Virais/genética , VacinaçãoRESUMO
ABSTRACTProlonged infection and possible evolution of SARS-CoV-2 in patients living with uncontrolled HIV-1 infection highlight the importance of an effective vaccination regimen, yet the immunogenicity of COVID-19 vaccines and predictive immune biomarkers have not been well investigated. Herein, we report that the magnitude and persistence of antibody and cell-mediated immunity (CMI) elicited by an Ad5-vectored COVID-19 vaccine are impaired in SIV-infected macaques with high viral loads (> 105 genome copies per ml plasma, SIVhi) but not in macaques with low viral loads (< 105, SIVlow). After a second vaccination, the immune responses are robustly enhanced in all uninfected and SIVlow macaques. These responses also show a moderate increase in 70% SIVhi macaques but decline sharply soon after. Further analysis reveals that decreased antibody and CMI responses are associated with reduced circulating follicular helper T cell (TFH) counts and aberrant CD4/CD8 ratios, respectively, indicating that dysregulation of CD4+ T cells by SIV infection impairs the COVID-19 vaccine-induced immunity. Ad5-vectored COVID-19 vaccine shows no impact on SIV loads or SIV-specific CMI responses. Our study underscores the necessity of frequent booster vaccinations in HIV-infected patients and provides indicative biomarkers for predicting vaccination effectiveness in these patients.
Assuntos
COVID-19 , Vacinas contra a SAIDS , Síndrome de Imunodeficiência Adquirida dos Símios , Vírus da Imunodeficiência Símia , Animais , Humanos , Vírus da Imunodeficiência Símia/genética , Vacinas contra COVID-19 , Anticorpos Antivirais , Macaca mulatta , Vacinas contra a SAIDS/genética , SARS-CoV-2 , VacinaçãoRESUMO
Although the clinical manifestation of COVID-19 is mainly respiratory symptoms, approximately 20% of patients suffer from cardiac complications. COVID-19 patients with cardiovascular disease have higher severity of myocardial injury and poor outcomes. The underlying mechanism of myocardial injury caused by SARS-CoV-2 infection remains unclear. Using a non-transgenic mouse model infected with Beta variant (B.1.351), we found that the viral RNA could be detected in lungs and hearts of infected mice. Pathological analysis showed thinner ventricular wall, disorganized and ruptured myocardial fiber, mild inflammatory infiltration, and mild epicardia or interstitial fibrosis in hearts of infected mice. We also found that SARS-CoV-2 could infect cardiomyocytes and produce infectious progeny viruses in human pluripotent stem cell-derived cardiomyocyte-like cells (hPSC-CMs). SARS-CoV-2 infection caused apoptosis, reduction of mitochondrial integrity and quantity, and cessation of beating in hPSC-CMs. In order to dissect the mechanism of myocardial injury caused by SARS-CoV-2 infection, we employed transcriptome sequencing of hPSC-CMs at different time points after viral infection. Transcriptome analysis showed robust induction of inflammatory cytokines and chemokines, up-regulation of MHC class I molecules, activation of apoptosis signaling and cell cycle arresting. These may cause aggravate inflammation, immune cell infiltration, and cell death. Furthermore, we found that Captopril (hypotensive drugs targeting ACE) treatment could alleviate SARS-CoV-2 induced inflammatory response and apoptosis in cardiomyocytes via inactivating TNF signaling pathways, suggesting Captopril may be beneficial for reducing COVID-19 associated cardiomyopathy. These findings preliminarily explain the molecular mechanism of pathological cardiac injury caused by SARS-CoV-2 infection, providing new perspectives for the discovery of antiviral therapeutics.
Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Camundongos , Animais , Captopril/farmacologia , Captopril/metabolismo , Miócitos Cardíacos , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Inibidores da Enzima Conversora de Angiotensina/metabolismo , Inflamação/tratamento farmacológico , Inflamação/metabolismo , ApoptoseRESUMO
Latent viral reservoir is recognized as the major obstacle to achieving a functional cure for HIV infection. We previously reported that arsenic trioxide (As2O3) combined with antiretroviral therapy (ART) can reactivate the viral reservoir and delay viral rebound after ART interruption in chronically simian immunodeficiency virus (SIV)-infected macaques. In this study, we further investigated the effect of As2O3 independent of ART in chronically SIV-infected macaques. We found that As2O3-only treatment significantly increased the CD4/CD8 ratio, improved SIV-specific T cell responses, and reactivated viral latency in chronically SIVmac239-infected macaques. RNA-sequencing analysis revealed that As2O3 treatment downregulated the expression levels of genes related to HIV entry and infection, while the expression levels of genes related to transcription initiation, cell apoptosis, and host restriction factors were significantly upregulated. Importantly, we found that As2O3 treatment specifically induced apoptosis of SIV-infected CD4+ T cells. These findings revealed that As2O3 might not only impact viral latency, but also induce the apoptosis of HIV-infected cells and thus block the secondary infection of bystanders. Moreover, we investigated the therapeutic potential of this regimen in acutely SIVmac239-infected macaques and found that As2O3 + ART treatment effectively restored the CD4+ T cell count, delayed disease progression, and improved survival in acutely SIV-infected macaques. In sum, this work provides new insights to develop As2O3 as a component of the "shock-and-kill" strategy toward HIV functional cure. IMPORTANCE Although antiretroviral therapy (ART) can effectively suppress the viral load of AIDS patients, it cannot functionally cure HIV infection due to the existence of HIV reservoir. Strategies toward HIV functional cure are still highly anticipated to ultimately end the pandemic of AIDS. Herein, we investigated the direct role of As2O3 independent of ART in chronically SIV-infected macaques and explored the underlying mechanisms of the potential of As2O3 in the treatment of HIV/SIV infection. Meanwhile, we investigated the therapeutic effects of ART+As2O3 in acutely SIVmac239-infected macaques. This study showed that As2O3 has the potential to be launched into the "shock-and-kill" strategy to suppress HIV/SIV reservoir due to its latency-reversing and apoptosis-inducing properties.
RESUMO
The highly contagious SARS-CoV-2 Omicron subvariants severely attenuated the effectiveness of currently licensed SARS-CoV-2 vaccines based on ancestral strains administered via intramuscular injection. In this study, we generated a recombinant, replication-incompetent human adenovirus type 5, Ad5-S-Omicron, that expresses Omicron BA.1 spike. Intranasal, but not intramuscular vaccination, elicited spike-specific respiratory mucosal IgA and residential T cell immune responses, in addition to systemic neutralizing antibodies and T cell immune responses against most Omicron subvariants. We tested intranasal Ad5-S-Omicron as a heterologous booster in mice that previously received intramuscular injection of inactivated ancestral vaccine. In addition to inducing serum broadly neutralizing antibodies, there was a significant induction of respiratory mucosal IgA and neutralizing activities against Omicron subvariants BA.1, BA.2, BA.5, BA.2.75, BF.7 as well as pre-Omicron strains Wildtype, Beta, and Delta. Serum and mucosal neutralizing activities against recently emerged XBB, BQ.1, and BQ.1.1 could also be detected but were much lower. Nasal lavage fluids from intranasal vaccination contained multimeric IgA that can bind to at least 10 spike proteins, including Omicron subvariants and pre-Omicron strains, and possessed broadly neutralizing activities. Intranasal vaccination using Ad5-S-Omicron or instillation of intranasal vaccinee's nasal lavage fluids in mouse nostrils protected mice against Omicron challenge. Taken together, intranasal Ad5-S-Omicron booster on the basis of ancestral vaccines can establish effective mucosal and systemic immunity against Omicron subvariants and multiple SARS-CoV-2 variants. This candidate vaccine warrants further development as a safe, effective, and user-friendly infection and transmission-blocking vaccine.
Assuntos
COVID-19 , Vacinas , Animais , Humanos , Camundongos , SARS-CoV-2 , Vacinas contra COVID-19/genética , COVID-19/prevenção & controle , Imunoglobulina ARESUMO
Homologous booster, heterologous booster, and Omicron variants breakthrough infection (OBI) could improve the humoral immunity against Omicron variants. Questions concerning about memory B cells (MBCs) and T cells immunity against Omicron variants, features of long-term immunity, after booster and OBI, needs to be explored. Here, comparative analysis demonstrate antibody and T cell immunity against ancestral strain, Delta and Omicron variants in Omicron breakthrough infected patients (OBIPs) are comparable to that in Ad5-nCoV boosted healthy volunteers (HVs), higher than that in inactivated vaccine (InV) boosted HVs. However, memory B cells (MBCs) immunity against Omicron variants was highest in OBIPs, followed by Ad5-nCoV boosted and InV boosted HVs. OBIPs and Ad5-nCoV boosted HVs have higher classical MBCs and activated MBCs, and lower naïve MBCs and atypical MBCs relative to both vaccine boosted HVs. Collectively, these data indicate Omicron breakthrough infection elicit higher MBCs and T cells against SARS-CoV-2 especially Omicron variants relative to homologous InV booster and heterologous Ad5-nCoV booster.
Assuntos
Infecções Irruptivas , COVID-19 , Humanos , SARS-CoV-2 , Anticorpos , Anticorpos Antivirais , Anticorpos NeutralizantesRESUMO
The immunogenicity of SARS-CoV-2 vaccines is poor in kidney transplant recipients (KTRs). The factors related to poor immunogenicity to vaccination in KTRs are not well defined. Here, observational study demonstrated no severe adverse effects were observed in KTRs and healthy participants (HPs) after first or second dose of SARS-CoV-2 inactivated vaccine. Different from HPs with excellent immunity against SARS-CoV-2, IgG antibodies against S1 subunit of spike protein, receptor-binding domain, and nucleocapsid protein were not effectively induced in a majority of KTRs after the second dose of inactivated vaccine. Specific T cell immunity response was detectable in 40% KTRs after the second dose of inactivated vaccine. KTRs who developed specific T cell immunity were more likely to be female, and have lower levels of total bilirubin, unconjugated bilirubin, and blood tacrolimus concentrations. Multivariate logistic regression analysis found that blood unconjugated bilirubin and tacrolimus concentration were significantly negatively associated with SARS-CoV-2 specific T cell immunity response in KTRs. Altogether, these data suggest compared to humoral immunity, SARS-CoV-2 specific T cell immunity response are more likely to be induced in KTRs after administration of inactivated vaccine. Reduction of unconjugated bilirubin and tacrolimus concentration might benefit specific cellular immunity response in KTRs following vaccination.
Assuntos
COVID-19 , Transplante de Rim , Feminino , Humanos , Masculino , Tacrolimo , Vacinas contra COVID-19 , COVID-19/prevenção & controle , SARS-CoV-2 , Imunidade Celular , Bilirrubina , Imunidade Humoral , Transplantados , Vacinação , Anticorpos AntiviraisRESUMO
HIV-1 CRF07_BC-p6Δ7, a strain with a seven amino acid deletion in the p6 region of the Gag protein, is becoming the dominant strain of HIV transmission among men who have sex with men (MSM) in China. Previous studies demonstrated that HIV-1 patients infected by CRF07_BC-p6Δ7 strain had lower viral load and slower disease progression than those patients infected with CRF07_BC wild-type strain. However, the underlying mechanism for this observation is not fully clarified yet. In this study, we constructed the recombinant DNA plasmid and adenovirus type 2 (Ad2) vector-based constructs to express the HIV-1 CRF07_BC Gag antigen with or without p6Δ7 mutation and then investigated their immunogenicity in mice. Our results showed that HIV-1 CRF07_BC Gag antigen with p6Δ7 mutation induced a comparable level of Gag-specific antibodies but stronger CD4+ and CD8+ T-cell immune responses than that of CRF07_BC Gag (07_BC-wt). Furthermore, we identified a series of T-cell epitopes, which induced strong T-cell immune response and cross-immunity with CRF01_AE Gag. These findings implied that the p6Gag protein with a seven amino acid deletion might enhance the Gag immunogenicity in particular cellular immunity, which provides valuable information to clarify the pathogenic mechanism of HIV-1 CRF07_BC-p6Δ7 and to develop precise vaccine strategies against HIV-1 infection.
Assuntos
Epitopos de Linfócito T , HIV-1 , Produtos do Gene gag do Vírus da Imunodeficiência Humana , Aminoácidos , Animais , Antígenos Virais , Infecções por HIV/virologia , HIV-1/genética , Homossexualidade Masculina , Humanos , Masculino , Camundongos , Minorias Sexuais e de Gênero , Produtos do Gene gag do Vírus da Imunodeficiência Humana/genética , Produtos do Gene gag do Vírus da Imunodeficiência Humana/imunologiaRESUMO
Preclinical studies have shown that the induction of secretory IgA (sIgA) in mucosa and neutralizing antibodies (NAbs) in sera is essential for designing vaccines that can effectively block the transmission of HIV-1. We previously showed that a vaccine consisting of bacterium-like particles (BLPs) displaying Protan-gp120AE-MTQ (PAM) could induce mucosal immune responses through intranasal (IN) immunization in mice and NAbs through intramuscular (IM) immunization in guinea pigs. Here, we evaluated the ability of this vaccine BLP-PAM to elicit HIV-1-specific mucosal and systemic immune responses through IN and IM immunization combination strategies in rhesus macaques. First, the morphology, antigenicity and epitope accessibility of the vaccine were analysed by transmission electron microscopy, bio-layer interferometry and ELISA. In BLP-PAM-immunized macaques, HIV-1-specific sIgA were rapidly induced through IN immunization in situ and distant mucosal sites, although the immune responses are relatively weak. Furthermore, the HIV-1-specific IgG and IgA antibody levels in mucosal secretions were enhanced and maintained, while production of serum NAbs against heterologous HIV-1 tier 1 and 2 pseudoviruses was elicited after IM boost. Additionally, situ mucosal responses and systemic T cell immune responses were improved by rAd2-gp120AE boost immunization via the IN and IM routes. These results suggested that BLP-based delivery in combination with the IN and IM immunization approach represents a potential vaccine strategy against HIV-1.