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1.
Front Cell Infect Microbiol ; 14: 1408245, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39006742

RESUMO

While simian immunodeficiency virus (SIV) infection is non-pathogenic in naturally infected African nonhuman primate hosts, experimental or accidental infection in rhesus macaques often leads to AIDS. Baboons, widely distributed throughout Africa, do not naturally harbor SIV, and experimental infection of baboons with SIVmac results in transient low-level viral replication. Elucidation of mechanisms of natural immunity in baboons could uncover new targets of antiviral intervention. We tested the hypothesis that an SIVmac adapted to replicate in baboon primary cells will gain the capacity to establish chronic infections in vivo. Here, we generated SIVmac variants in baboon cells through serial passage in PBMC from different donors (SIVbn-PBMC s1), in PBMC from the same donors (SIVbn-PBMC s2), or in isolated CD4 cells from the same donors used for series 2 (SIVbn-CD4). While SIVbn-PBMC s1 and SIVbn-CD4 demonstrated increased replication capacity, SIVbn-PBMC s2 did not. Pharmacological blockade of CCR5 revealed SIVbn-PBMC s1 could more efficiently use available CCR5 than SIVmac, a trait we hypothesize arose to circumvent receptor occupation by chemokines. Sequencing analysis showed that all three viruses accumulated different types of mutations, and that more non-synonymous mutations became fixed in SIVbn-PBMC s1 than SIVbn-PBMC s2 and SIVbn-CD4, supporting the notion of stronger fitness pressure in PBMC from different genetic backgrounds. Testing the individual contribution of several newly fixed SIV mutations suggested that is the additive effect of these mutations in SIVbn-PBMC s1 that contributed to its enhanced fitness, as recombinant single mutant viruses showed no difference in replication capacity over the parental SIVmac239 strain. The replicative capacity of SIVbn-PBMC passage 4 (P4) s1 was tested in vivo by infecting baboons intravenously with SIVbn-PBMC P4 s1 or SIVmac251. While animals infected with SIVmac251 showed the known pattern of transient low-level viremia, animals infected with SIVbn-PBMC P4 s1 had undetectable viremia or viral DNA in lymphoid tissue. These studies suggest that adaptation of SIV to grow in baboon primary cells results in mutations that confer increased replicative capacity in the artificial environment of cell culture but make the virus unable to avoid the restrictive factors generated by a complex multicellular organism.


Assuntos
Papio , Síndrome de Imunodeficiência Adquirida dos Símios , Vírus da Imunodeficiência Símia , Replicação Viral , Animais , Vírus da Imunodeficiência Símia/genética , Vírus da Imunodeficiência Símia/fisiologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Leucócitos Mononucleares/virologia , Leucócitos Mononucleares/imunologia , Receptores CCR5/metabolismo , Receptores CCR5/genética , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD4-Positivos/imunologia , Células Cultivadas , Inoculações Seriadas
3.
APMIS ; 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38961316

RESUMO

SARS-CoV-2 variants of concern (VOC), such as Delta and Omicron have harbored mutations, which increased viral infectivity or ability to evade neutralizing antibodies. Immunocompromised patients might be a source of some of these emerging variants. In this study, we sequenced 17 consecutive samples from an immunocompromised patient with a long-term SARS-CoV-2 infection with the pre-VOC era lineage B.1.177.35. We here describe the emergence of 73 nonsynonymous minority variants in this patient and show that 10 of these mutations became dominant in the viral population during the treatment period. Four of these were seen throughout the infection period and had a very low global prevalence, although three of them were also observed later in the Alpha, Delta, and Omicron lineages. We also found that two adjacent nsp12 variants (M785I and S786P) belonged to different quasi-species and competed during the early stages of infection and remdesivir administration. This emphasizes the importance of ongoing genome surveillance of SARS-CoV-2 among immunocpromised patients.

4.
bioRxiv ; 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-39005312

RESUMO

Toxoplasma gondii causes widespread chronic infections that are not cured by current treatments due to inability to affect semi-dormant bradyzoite stages within tissue cysts. To identify compounds to eliminate chronic infection, we developed a HTS using a recently characterized strain of T. gondii that undergoes efficient conversion to bradyzoites in intro. Stage-specific expression of luciferase was used to selectively monitor growth inhibition of bradyzoites by the Library of Pharmacological Active Compounds, consisting of 1280 drug-like compounds. We identified 44 compounds with >50% inhibitory effects against bradyzoites, including several new highly potent compounds several of which have precedent for antimicrobial activity. Subsequent characterization of the compound Sanguinarine sulfate revealed potent and rapid killing against in vitro produced bradyzoites and bradyzoites harvested from chronically infected mice. These findings provide a platform for expanded screening and identify promising compounds for further preclinical development against T. gondii bradyzoites responsible for chronic infection.

5.
Ecotoxicol Environ Saf ; 282: 116709, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39024943

RESUMO

Biofilms, intricate microbial communities that attach to surfaces, especially medical devices, form an exopolysaccharide matrix, which enables bacteria to resist environmental pressures and conventional antimicrobial agents, leading to the emergence of multi-drug resistance. Biofilm-related infections associated with medical devices are a significant public health threat, compromising device performance. Therefore, developing effective methods for supervising and managing biofilm growth is imperative. This in-depth review presents a systematic overview of strategies for monitoring and controlling bacterial biofilms. We first outline the biofilm creation process and its regulatory mechanisms. The discussion then progresses to advancements in biosensors for biofilm detection and diverse treatment strategies. Lastly, this review examines the obstacles and new perspectives associated with this domain to facilitate the advancement of innovative monitoring and control solutions. These advancements are vital in combating the spread of multi drug-resistant bacteria and mitigating public health risks associated with infections from biofilm formation on medical instruments.

6.
Parasit Vectors ; 17(1): 252, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38858789

RESUMO

BACKGROUND: Toxoplasma gondii is an intracellular protozoan parasite that is widely distributed in humans and warm-blooded animals. T. gondii chronic infections can cause toxoplasmic encephalopathy, adverse pregnancy, and male reproductive disorders. In male reproduction, the main function of the testis is to provide a stable place for spermatogenesis and immunological protection. The disorders affecting testis tissue encompass abnormalities in the germ cell cycle, spermatogenic retardation, or complete cessation of sperm development. However, the mechanisms of interaction between T. gondii and the reproductive system is unclear. The aims were to study the expression levels of genes related to spermatogenesis, following T. gondii infection, in mouse testicular tissue. METHODS: RNA-seq sequencing was carried out on mouse testicular tissues from mice infected or uninfected with the T. gondii type II Prugniaud (PRU) strain and validated in combination with real-time quantitative PCR and immunofluorescence assays. RESULTS: The results showed that there were 250 significant differentially expressed genes (DEGs) (P < 0.05, |log2fold change| â‰§ 1). Bioinformatics analysis showed that 101 DEGs were annotated to the 1696 gene ontology (GO) term. While there was a higher number of DEGs in the biological process classification as a whole, the GO enrichment revealed a significant presence of DEGs in the cellular component classification. The Arhgap18 and Syne1 genes undergo regulatory changes following T. gondii infection, and both were involved in shaping the cytoskeleton of the blood-testis barrier (BTB). The number of DEGs enriched in the MAPK signaling pathway, the ERK1/2 signaling pathway, and the JNK signaling pathway were significant. The PTGDS gene is located in the Arachidonic acid metabolism pathway, which plays an important role in the formation and maintenance of BTB in the testis. The expression of PTGDS is downregulated subsequent to T. gondii infection, potentially exerting deleterious effects on the integrity of the BTB and the spermatogenic microenvironment within the testes. CONCLUSIONS: Overall, our research provides in-depth insights into how chronic T. gondii infection might affect testicular tissue and potentially impact male fertility. These findings offer a new perspective on the impact of T. gondii infection on the male reproductive system.


Assuntos
Testículo , Toxoplasma , Toxoplasmose Animal , Transcriptoma , Animais , Masculino , Camundongos , Testículo/parasitologia , Testículo/metabolismo , Toxoplasma/genética , Toxoplasmose Animal/parasitologia , Espermatogênese/genética , Perfilação da Expressão Gênica , Doença Crônica , Biologia Computacional
7.
Hepatol Res ; 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38874115

RESUMO

Acute hepatitis E was considered rare until reports emerged affirming the existence of hepatitis E virus (HEV) genotypes 3 and 4 infections in Japan in the early 2000s. Extensive studies by Japanese researchers have highlighted the pivotal role of pigs and wild animals, such as wild boars and deer, as reservoirs for HEV, linking them to zoonotic infections in Japan. Currently, when hepatitis occurs subsequent to the consumption of undercooked or grilled pork, wild boar meat, or offal (including pig liver and intestines), HEV infection should be considered. Following the approval of anti-HEV immunoglobulin A antibody as a diagnostic tool for hepatitis E by Japan's Health Insurance System in 2011, the annual number of diagnosed cases of HEV infection has surged. Notably, the occurrence of post-transfusion hepatitis E promoted nationwide screening of blood products for HEV using nucleic acid amplification tests since 2020. Furthermore, chronic hepatitis E has been observed in immunosuppressed individuals. Considering the significance of hepatitis E, heightened preventive measures are essential. The Japan Agency for Medical Research and Development Hepatitis A and E viruses (HAV and HEV) Study Group, which includes special virologists and hepatologists, held a virtual meeting on February 17, 2024. Discussions encompassed pathogenesis, transmission routes, diagnosis, complications, severity factors, and ongoing and prospective vaccination or treatments for hepatitis E. Rigorous assessment of referenced studies culminated in the formulation of recommendations, which are detailed within this review. This comprehensive review presents recent advancements in HEV research and Japanese clinical practice guidelines for HEV infection.

8.
J Med Virol ; 96(6): e29735, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38864313

RESUMO

Recently, hepatitis E virus (HEV, Paslahepevirus balayani) particles were detected for the first time in the ejaculate of two chronically infected patients. Since then, we have been able to detect HEV in ejaculate in five further patients, and thus in a total of seven out of nine (78%) chronically infected men (age 36-67 years, median 56 years). In five patients, the HEV RNA concentration was more than 100-fold higher compared to the serum, while in two patients, the viral load was more than 10-fold lower. However, it has remained unclear whether viral particles shed in the ejaculate were infectious, as a previous cell culture model had failed to demonstrate the infectivity. In the current study, we employed an optimized HEV cell culture system based on overconfluent PLC/PRF/5 cells to investigate the infectivity of HEV particles from ejaculate and other body fluids. With this approach, we were able to show for the first time that HEV particles in the ejaculate from several patients were infectious. HEV replicated to high viral loads of 1e9 HEV RNA copies per ml. This indicates that HEV-positive ejaculate could bear a risk of infection for sexual partners.


Assuntos
Vírus da Hepatite E , Hepatite E , RNA Viral , Carga Viral , Humanos , Vírus da Hepatite E/isolamento & purificação , Pessoa de Meia-Idade , Hepatite E/virologia , Masculino , Adulto , Idoso , RNA Viral/análise , Sêmen/virologia , Vírion , Linhagem Celular , Eliminação de Partículas Virais
9.
Medicina (Kaunas) ; 60(6)2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38929615

RESUMO

Hepatitis E virus (HEV) infection is typically a self-limiting, acute illness that spreads through the gastrointestinal tract but replicates in the liver. However, chronic infections are possible in immunocompromised individuals. The HEV virion has two shapes: exosome-like membrane-associated quasi-enveloped virions (eHEV) found in circulating blood or in the supernatant of infected cell cultures and non-enveloped virions ("naked") found in infected hosts' feces and bile to mediate inter-host transmission. Although HEV is mainly spread via enteric routes, it is unclear how it penetrates the gut wall to reach the portal bloodstream. Both virion types are infectious, but they infect cells in different ways. To develop personalized treatment/prevention strategies and reduce HEV impact on public health, it is necessary to decipher the entry mechanism for both virion types using robust cell culture and animal models. The contemporary knowledge of the cell entry mechanism for these two HEV virions as possible therapeutic target candidates is summarized in this narrative review.


Assuntos
Vírus da Hepatite E , Hepatite E , Humanos , Vírus da Hepatite E/fisiologia , Vírus da Hepatite E/patogenicidade , Hepatite E/transmissão , Hepatite E/virologia , Vírion/fisiologia , Animais
10.
Proc Natl Acad Sci U S A ; 121(24): e2403054121, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38838017

RESUMO

Chronic Toxoplasma gondii infection induces brain-resident CD8+ T cells (bTr), but the protective functions and differentiation cues of these cells remain undefined. Here, we used a mouse model of latent infection by T. gondii leading to effective CD8+ T cell-mediated parasite control. Thanks to antibody depletion approaches, we found that peripheral circulating CD8+ T cells are dispensable for brain parasite control during chronic stage, indicating that CD8+ bTr are able to prevent brain parasite reactivation. We observed that the retention markers CD69, CD49a, and CD103 are sequentially acquired by brain parasite-specific CD8+ T cells throughout infection and that a majority of CD69/CD49a/CD103 triple-positive (TP) CD8+ T cells also express Hobit, a transcription factor associated with tissue residency. This TP subset develops in a CD4+ T cell-dependent manner and is associated with effective parasite control during chronic stage. Conditional invalidation of Transporter associated with Antigen Processing (TAP)-mediated major histocompatibility complex (MHC) class I presentation showed that presentation of parasite antigens by glutamatergic neurons and microglia regulates the differentiation of CD8+ bTr into TP cells. Single-cell transcriptomic analyses revealed that resistance to encephalitis is associated with the expansion of stem-like subsets of CD8+ bTr. In summary, parasite-specific brain-resident CD8+ T cells are a functionally heterogeneous compartment which autonomously ensure parasite control during T. gondii latent infection and which differentiation is shaped by neuronal and microglial MHC I presentation. A more detailed understanding of local T cell-mediated immune surveillance of this common parasite is needed for harnessing brain-resident CD8+ T cells in order to enhance control of chronic brain infections.


Assuntos
Encéfalo , Linfócitos T CD8-Positivos , Diferenciação Celular , Toxoplasma , Toxoplasmose , Animais , Linfócitos T CD8-Positivos/imunologia , Toxoplasma/imunologia , Camundongos , Encéfalo/imunologia , Encéfalo/parasitologia , Diferenciação Celular/imunologia , Toxoplasmose/imunologia , Toxoplasmose/parasitologia , Infecção Latente/imunologia , Infecção Latente/parasitologia , Antígenos CD/metabolismo , Antígenos CD/imunologia , Antígenos CD/genética , Camundongos Endogâmicos C57BL , Feminino
11.
J Virol ; 98(7): e0084624, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-38899900

RESUMO

Chronic hepatitis E mostly occurs in organ transplant recipients and can lead to rapid liver fibrosis and cirrhosis. Previous studies found that the development of chronic hepatitis E virus (HEV) infection is linked to the type of immunosuppressant used. Animal models are crucial for the study of pathogenesis of chronic hepatitis E. We previously established a stable chronic HEV infection rabbit model using cyclosporine A (CsA), a calcineurin inhibitor (CNI)-based immunosuppressant. However, the immunosuppression strategy and timing may be optimized, and how different types of immunosuppressants affect the establishment of chronic HEV infection in this model is still unknown. Here, we showed that chronic HEV infection can be established in 100% of rabbits when CsA treatment was started at HEV challenge or even 4 weeks after. Tacrolimus or prednisolone treatment alone also contributed to chronic HEV infection, resulting in 100% and 77.8% chronicity rates, respectively, while mycophenolate mofetil (MMF) only led to a 28.6% chronicity rate. Chronic HEV infection was accompanied with a persistent activation of innate immune response evidenced by transcriptome analysis. The suppressed adaptive immune response evidenced by low expression of genes related to cytotoxicity (like perforin and FasL) and low anti-HEV seroconversion rates may play important roles in causing chronic HEV infection. By analyzing HEV antigen concentrations with different infection outcomes, we also found that HEV antigen levels could indicate chronic HEV infection development. This study optimized the immunosuppression strategies for establishing chronic HEV infection in rabbits and highlighted the potential association between the development of chronic HEV infection and immunosuppressants.IMPORTANCEOrgan transplant recipients are at high risk of chronic hepatitis E and generally receive a CNI-based immunosuppression regimen containing CNI (tacrolimus or CsA), MMF, and/or corticosteroids. Previously, we established stable chronic HEV infection in a rabbit model by using CsA before HEV challenge. In this study, we further optimized the immunosuppression strategies for establishing chronic HEV infection in rabbits. Chronic HEV infection can also be established when CsA treatment was started at the same time or even 4 weeks after HEV challenge, clearly indicating the risk of progression to chronic infection under these circumstances and the necessity of HEV screening for both the recipient and the donor preoperatively. CsA, tacrolimus, or prednisolone instead of MMF significantly contributed to chronic HEV infection. HEV antigen in acute infection phase indicates the development of chronic infection. Our results have important implications for understanding the potential association between chronic HEV infection and immunosuppressants.


Assuntos
Ciclosporina , Modelos Animais de Doenças , Vírus da Hepatite E , Hepatite E , Terapia de Imunossupressão , Imunossupressores , Tacrolimo , Animais , Coelhos , Hepatite E/imunologia , Hepatite E/virologia , Hepatite E/tratamento farmacológico , Vírus da Hepatite E/imunologia , Imunossupressores/farmacologia , Imunossupressores/uso terapêutico , Ciclosporina/farmacologia , Ciclosporina/uso terapêutico , Tacrolimo/farmacologia , Tacrolimo/uso terapêutico , Prednisolona/uso terapêutico , Prednisolona/farmacologia , Masculino , Imunidade Inata/efeitos dos fármacos , Ácido Micofenólico/farmacologia , Hepatite Crônica/tratamento farmacológico , Hepatite Crônica/imunologia , Hepatite Crônica/virologia , Doença Crônica , Inibidores de Calcineurina/farmacologia , Inibidores de Calcineurina/uso terapêutico
12.
Adv Virus Res ; 119: 63-110, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38897709

RESUMO

The surfaces of cells and enveloped viruses alike are coated in carbohydrates that play multifarious roles in infection and immunity. Organisms across all kingdoms of life make use of a diverse set of monosaccharide subunits, glycosidic linkages, and branching patterns to encode information within glycans. Accordingly, sugar-patterning enzymes and glycan binding proteins play integral roles in cell and organismal biology, ranging from glycoprotein quality control within the endoplasmic reticulum to lymphocyte migration, coagulation, inflammation, and tissue homeostasis. Unsurprisingly, genes involved in generating and recognizing oligosaccharide patterns are playgrounds for evolutionary conflicts that abound in cross-species interactions, exemplified by the myriad plant lectins that function as toxins. In vertebrates, glycans bearing acidic nine-carbon sugars called sialic acids are key regulators of immune responses. Various bacterial and fungal pathogens adorn their cells in sialic acids that either mimic their hosts' or are stolen from them. Yet, how viruses commandeer host sugar-patterning enzymes to thwart immune responses remains poorly studied. Here, we review examples of viruses that interact with sialic acid-binding immunoglobulin-like lectins (Siglecs), a family of immune cell receptors that regulate toll-like receptor signaling and govern glycoimmune checkpoints, while highlighting knowledge gaps that merit investigation. Efforts to illuminate how viruses leverage glycan-dependent checkpoints may translate into new clinical treatments that uncloak viral antigens and infected cell surfaces by removing or masking immunosuppressive sialoglycans, or by inhibiting viral gene products that induce their biosynthesis. Such approaches may hold the potential to unleash the immune system to clear long intractable chronic viral infections.


Assuntos
Glicocálix , Vírus , Glicocálix/metabolismo , Humanos , Animais , Vírus/imunologia , Vírus/metabolismo , Polissacarídeos/metabolismo , Lectinas Semelhantes a Imunoglobulina de Ligação ao Ácido Siálico/metabolismo , Viroses/imunologia , Viroses/metabolismo , Viroses/virologia , Interações Hospedeiro-Patógeno/imunologia
13.
Vet Res Commun ; 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38916691

RESUMO

Toxoplasma gondii (T. gondii) is an obligate intracellular parasite of warm-blooded vertebrates. At present, High-throughput RNA sequencing analysis have made it possible to determine the role of effective genes in host immune response. The aim of the present study is to global transcriptome analysis of the brain of mice infected with T. gondii Tehran strain for the first time and also to evaluate the expression of effective genes in the chronic form of infection. RNA was extracted from the samples and the library was prepared and sequenced using the IlluminaNovaSeq 6000 system. After analyzing gene expression changes, the results were confirmed by real-time method. We found 125 genes that were significantly differentially expressed between infected and non-infected samples (p < 0.0005). Gene ontology analysis revealed that the expression of many genes is critical for pathways such as T cell receptor signaling pathway, Natural Killer cell mediated cytotoxicity, Lysosome and Apoptosis of the host. As infection with Tehran strain leads to chronic infection in mice, therefore, we investigated the genes effective in creating the chronic form of Toxoplasma infection. The comparative analysis of genes showed increases in the expression of genes ctla4, ccl4, cd3e, c3, lcn2, gbp5, usp18, cyba, tap1 and samhd1 in the in the infected sample, which highlights their role in causing chronic infection. RNA-seq provides a valuable tool for analyzing host transcriptomes, better understanding the parasite-host interaction, and developing future drug and vaccine targets.

14.
Vet Microbiol ; 294: 110119, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38772075

RESUMO

Mycoplasma synoviae causes infectious synovitis and respiratory tract infections in chickens and is responsible for significant economic losses in the poultry industry. Effective attachment and colonisation of the trachea is critical for the persistence of the organism and progression of the disease it causes. The respiratory tract infection is usually sub-clinical, but concurrent infection with infectious bronchitis virus (IBV) is known to enhance the pathogenicity of M. synoviae. This study aimed to explore differentially expressed genes in the tracheal mucosa, and their functional categories, during chronic infection with M. synoviae, using a M. synoviae-IBV infection model. The transcriptional profiles of the trachea were assessed 2 weeks after infection using RNA sequencing. In chickens infected with M. synoviae or IBV, only 1 or 8 genes were differentially expressed compared to uninfected chickens, respectively. In contrast, the M. synoviae-IBV infected chickens had 621 upregulated and 206 downregulated genes compared to uninfected chickens. Upregulated genes and their functional categories were suggestive of uncontrolled lymphoid cell proliferation and an ongoing pro-inflammatory response. Genes associated with anti-inflammatory effects, pathogen removal, apoptosis, regulation of the immune response, airway homoeostasis, cell adhesion and tissue regeneration were downregulated. Overall, transcriptional changes in the trachea, 2 weeks after infection with M. synoviae and IBV, indicate immune dysregulation, robust inflammation and a lack of cytotoxic damage during chronic infection. This model provides insights into the pathogenesis of chronic infection with M. synoviae.


Assuntos
Galinhas , Infecções por Mycoplasma , Mycoplasma synoviae , Doenças das Aves Domésticas , Traqueia , Animais , Infecções por Mycoplasma/veterinária , Infecções por Mycoplasma/microbiologia , Infecções por Mycoplasma/imunologia , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/virologia , Doenças das Aves Domésticas/imunologia , Mycoplasma synoviae/genética , Traqueia/microbiologia , Traqueia/virologia , Vírus da Bronquite Infecciosa/genética , Vírus da Bronquite Infecciosa/imunologia , Vírus da Bronquite Infecciosa/fisiologia , Doença Crônica , Infecções por Coronavirus/veterinária , Infecções por Coronavirus/virologia , Infecções por Coronavirus/imunologia , Transcriptoma , Perfilação da Expressão Gênica , Coinfecção/veterinária , Coinfecção/microbiologia , Coinfecção/virologia
15.
J Virol ; 98(6): e0027324, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38775481

RESUMO

TIGIT is a negative immune checkpoint receptor associated with T cell exhaustion in cancer and HIV. TIGIT upregulation in virus-specific CD8+ T cells and NK cells during HIV/SIV infection results in dysfunctional effector capabilities. In vitro studies targeting TIGIT on CD8+ T cells suggest TIGIT blockade as a viable strategy to restore SIV-specific T cell responses. Here, we extend these studies in vivo using TIGIT blockage in nonhuman primates in an effort to reverse T cell and NK cell exhaustion in the setting of SIV infection. We demonstrate that in vivo administration of a humanized anti-TIGIT monoclonal antibody (mAb) is well tolerated in both cynomolgus macaques and rhesus macaques. Despite sustained plasma concentrations of anti-TIGIT mAb, we observed no consistent improvement in NK or T cell cytolytic capacity. TIGIT blockade minimally enhanced T cell proliferation and virus-specific T cell responses in both magnitude and breadth though plasma viral loads in treated animals remained stable indicating that anti-TIGIT mAb treatment alone was insufficient to increase anti-SIV CD8+ T cell function. The enhancement of virus-specific T cell proliferative responses observed in vitro with single or dual blockade of TIGIT and/or PD-1 highlights TIGIT as a potential target to reverse T cell dysfunction. Our studies, however, reveal that targeting the TIGIT pathway alone may be insufficient in the setting of viremia and that combining immune checkpoint blockade with other immunotherapeutics may be a future path forward for improved viral control or elimination of HIV.IMPORTANCEUpregulation of the immune checkpoint receptor TIGIT is associated with HIV-mediated T cell dysfunction and correlates with HIV disease progression. Compelling evidence exists for targeting immune checkpoint receptor pathways that would potentially enhance immunity and refocus effector cell efforts toward viral clearance. In this report, we investigate TIGIT blockade as an immunotherapeutic approach to reverse immune exhaustion during chronic SIV/SHIV infection in a nonhuman primate model of HIV infection. We show that interfering with the TIGIT signaling axis alone is insufficient to improve viral control despite modest improvement in T cell immunity. Our data substantiate the use of targeting multiple immune checkpoint receptors to promote synergy and ultimately eliminate HIV-infected cells.


Assuntos
Linfócitos T CD8-Positivos , Células Matadoras Naturais , Macaca fascicularis , Macaca mulatta , Receptores Imunológicos , Síndrome de Imunodeficiência Adquirida dos Símios , Vírus da Imunodeficiência Símia , Carga Viral , Animais , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/tratamento farmacológico , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/imunologia , Receptores Imunológicos/antagonistas & inibidores , Linfócitos T CD8-Positivos/imunologia , Carga Viral/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais/farmacologia
16.
Sci Rep ; 14(1): 10433, 2024 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-38714696

RESUMO

Toxoplasma gondii (T. gondii) is a protozoan parasite that infects approximately one-third of the global human population, often leading to chronic infection. While acute T. gondii infection can cause neural damage in the central nervous system and result in toxoplasmic encephalitis, the consequences of T. gondii chronic infection (TCI) are generally asymptomatic. However, emerging evidence suggests that TCI may be linked to behavioral changes or mental disorders in hosts. Astrocyte polarization, particularly the A1 subtype associated with neuronal apoptosis, has been identified in various neurodegenerative diseases. Nevertheless, the role of astrocyte polarization in TCI still needs to be better understood. This study aimed to establish a mouse model of chronic TCI and examine the transcription and expression levels of glial fibrillary acidic protein (GFAP), C3, C1q, IL-1α, and TNF-α in the brain tissues of the mice. Quantitative real-time PCR (qRT-PCR), enzyme-linked immunosorbent assay, and Western blotting were employed to assess these levels. Additionally, the expression level of the A1 astrocyte-specific marker C3 was evaluated using indirect fluorescent assay (IFA). In mice with TCI, the transcriptional and expression levels of the inflammatory factors C1q, IL-1α, and TNF-α followed an up-down-up pattern, although they remained elevated compared to the control group. These findings suggest a potential association between astrocyte polarization towards the A1 subtype and synchronized changes in these three inflammatory mediators. Furthermore, immunofluorescence assay (IFA) revealed a significant increase in the A1 astrocytes (GFAP+C3+) proportion in TCI mice. This study provides evidence that TCI can induce astrocyte polarization, a biological process that may be influenced by changes in the levels of three inflammatory factors: C1q, IL-1α, and TNF-α. Additionally, the release of neurotoxic substances by A1 astrocytes may be associated with the development of TCI.


Assuntos
Astrócitos , Encéfalo , Toxoplasma , Animais , Astrócitos/metabolismo , Astrócitos/parasitologia , Astrócitos/patologia , Camundongos , Toxoplasma/patogenicidade , Toxoplasma/fisiologia , Encéfalo/parasitologia , Encéfalo/metabolismo , Encéfalo/patologia , Modelos Animais de Doenças , Feminino , Doença Crônica , Polaridade Celular , Proteína Glial Fibrilar Ácida/metabolismo , Proteína Glial Fibrilar Ácida/genética , Toxoplasmose/metabolismo , Toxoplasmose/parasitologia , Toxoplasmose/patologia , Fator de Necrose Tumoral alfa/metabolismo , Toxoplasmose Cerebral/parasitologia , Toxoplasmose Cerebral/patologia , Toxoplasmose Cerebral/metabolismo
17.
Curr Rheumatol Rep ; 26(7): 248-259, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38568326

RESUMO

PURPOSE OF REVIEW: Amyloid A (AA) amyloidosis is an organ- or life-threatening complication of chronic inflammatory disorders. Here, we review the epidemiology, causes, pathogenesis, clinical features, and diagnostic and therapeutic strategies of AA amyloidosis. RECENT FINDINGS: The incidence of AA amyloidosis has declined due to better treatment of the underlying diseases. Histopathological examination is the gold standard of diagnosis, but magnetic resonance imaging can be used to detect cardiac involvement. There is yet no treatment option for the clearance of amyloid fibril deposits; therefore, the management strategy primarily aims to reduce serum amyloid A protein. Anti-inflammatory biologic agents have drastically expanded our therapeutic armamentarium. Kidney transplantation is preferred in patients with kidney failure, and the recurrence of amyloidosis in the allograft has become rare as transplant recipients have started to benefit from the new agents. The management of AA amyloidosis has been considerably changed over the recent years due to the novel therapeutic options aiming to control inflammatory activity. New agents capable of clearing amyloid deposits from the tissues are still needed.


Assuntos
Amiloidose , Humanos , Amiloidose/diagnóstico , Amiloidose/terapia , Proteína Amiloide A Sérica , Transplante de Rim
18.
Wound Repair Regen ; 32(4): 407-418, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38602090

RESUMO

An argon-based low-temperature plasma jet (LTPJ) was used to treat chronically infected wounds in Staphylococcus aureus-laden mice. Based on physicochemical property analysis and in vitro antibacterial experiments, the effects of plasma parameters on the reactive nitrogen and oxygen species (RNOS) content and antibacterial capacity were determined, and the optimal treatment parameters were determined to be 4 standard litre per minute and 35 W. Additionally, the plasma-treated activation solution had a bactericidal effect. Although RNOS are related to the antimicrobial effect of plasma, excess RNOS may be detrimental to wound remodelling. In vivo studies demonstrated that medium-dose LTPJ promoted MMP-9 expression and inhibited bacterial growth during the early stages of healing. Moreover, LTPJ increased collagen deposition, reduced inflammation, and restored blood vessel density and TGF-ß levels to normal in the later stages of wound healing. Therefore, when treating chronically infected wounds with LTPJ, selecting the medium dose of plasma is more advantageous for wound recovery. Overall, our study demonstrated that low-temperature plasma jets may be a potential tool for the treatment of chronically infected wounds.


Assuntos
Gases em Plasma , Staphylococcus aureus , Cicatrização , Infecção dos Ferimentos , Animais , Cicatrização/efeitos dos fármacos , Camundongos , Gases em Plasma/farmacologia , Infecção dos Ferimentos/microbiologia , Espécies Reativas de Oxigênio/metabolismo , Modelos Animais de Doenças , Infecções Estafilocócicas , Masculino , Espécies Reativas de Nitrogênio/metabolismo
19.
World J Virol ; 13(1): 88487, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38616853

RESUMO

Hepatitis B virus (HBV) reactivation poses a significant clinical challenge, especially in patients undergoing immunosuppressive therapies, including monoclonal antibody treatments. This manuscript briefly explores the complex relationship between monoclonal antibody therapy and HBV reactivation, drawing upon current literature and clinical case studies. It delves into the mechanisms underlying this phenomenon, highlighting the importance of risk assessment, monitoring, and prophylactic measures for patients at risk. The manuscript aims to enhance the understanding of HBV reactivation in the context of monoclonal antibody therapy, ultimately facilitating informed clinical decision-making and improved patient care. This paper will also briefly review the definition of HBV activation, assess the risks of reactivation, especially in patients treated with monoclonal antibodies, and consider management for patients with regard to screening, prophylaxis, and treatment. A better understanding of patients at risk can help clinicians provide optimum management to ensure successful patient outcomes and prevent morbidity.

20.
Cell Mol Immunol ; 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38459243

RESUMO

Mucosal surfaces that line the respiratory, gastrointestinal and genitourinary tracts are the major interfaces between the immune system and the environment. Their unique immunological landscape is characterized by the necessity of balancing tolerance to commensal microorganisms and other innocuous exposures against protection from pathogenic threats such as viruses. Numerous pathogenic viruses, including herpesviruses and retroviruses, exploit this environment to establish chronic infection. Effector and regulatory T-cell populations, including effector and resident memory T cells, play instrumental roles in mediating the transition from acute to chronic infection, where a degree of viral replication is tolerated to minimize immunopathology. Persistent antigen exposure during chronic viral infection leads to the evolution and divergence of these responses. In this review, we discuss advances in the understanding of mucosal T-cell immunity during chronic viral infections and how features of T-cell responses develop in different chronic viral infections of the mucosa. We consider how insights into T-cell immunity at mucosal surfaces could inform vaccine strategies: not only to protect hosts from chronic viral infections but also to exploit viruses that can persist within mucosal surfaces as vaccine vectors.

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