RESUMO
ACE2 and TMPRSS2 are crucial for SARS-CoV-2 entry into the cell. Although ACE2 facilitates viral entry, its loss leads to promoting the devastating clinical symptoms of COVID-19 disease. Thus, enhanced ACE2/TMPRSS2 expression is likely to increase predisposition of target cells to SARS-CoV-2 infection. However, little evidence existed about the biological kinetics of these two enzymes and whether dexamethasone treatment modulates their expression. Here, we show that the expression of ACE2 at the protein and mRNA levels was significantly higher in the lung and heart tissues of neonatal compared to adult mice. However, the expression of TMPRSS2 was developmentally regulated. Our results may introduce a novel concept for the reduced susceptibility of the young to SARS-CoV-2 infection. Moreover, ACE2 expression but not TMPRSS2 was upregulated in adult female lungs compared to their male counterparts. Interestingly, the ACE2 and TMPRSS2 expressions were upregulated by dexamethasone treatment in the lung and heart tissues in both neonatal and adult mice. Furthermore, our findings provide a novel mechanism for the observed differential therapeutic effects of dexamethasone in COVID-19 patients. As such, dexamethasone exhibits different therapeutic effects depending on the disease stage. This was supported by increased ACE2/TMPRSS2 expression and subsequently enhanced infection of normal human bronchial epithelial cells (NHBE) and Vero E6 cells with SARS-CoV-2 once pre-treated with dexamethasone. Therefore, our results suggest that individuals who take dexamethasone for other clinical conditions may become more prone to SARS-CoV-2 infection.
Assuntos
Enzima de Conversão de Angiotensina 2 , Tratamento Farmacológico da COVID-19 , Humanos , Masculino , Feminino , Camundongos , Animais , Enzima de Conversão de Angiotensina 2/genética , Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/metabolismo , SARS-CoV-2 , Dexametasona/farmacologia , Dexametasona/uso terapêutico , Serina Endopeptidases/genéticaRESUMO
HIV latency is a challenge to the success of antiretroviral therapy (ART). Hence patients may benefit from interventions that efficiently reactivate the latent virus to be eliminated by ARTs. Here we show that plasma extracellular vesicles (pEVs) can enhance HIV infection of activated CD4+ T cells and reactivate the virus in latently infected J-Lat 10.6 cells. Evaluation of the extravesicular miRNA cargo by a PCR array revealed that pEVs from HIV patients express miR-139-5p. Furthermore, we found that increased levels of miR-139-5p in J-Lat 10.6 cells incubated with pEVs corresponded with reduced expression of the transcription factor, FOXO1. pEV treatment also corresponded with increased miR-139-5p expression in stimulated PD1+ Jurkat cells, but with concomitant upregulation of FOXO1, Fos, Jun, PD-1 and PD-L1. However, J-Lat 10.6 cells incubated with miR-139-5p inhibitor-transfected pEVs from HIV ART-naïve and on-ART patients expressed reduced levels of miR-139-5p than cells treated with pEVs from healthy controls (HC). Collectively, our results indicate that pEV miR-139-5p belongs to a network of miRNAs that can promote cell activation, including latent HIV-infected cells by regulating the expression of FOXO1 and the PD1/PD-L1 promoters, Fos and Jun.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/virologia , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/patogenicidade , MicroRNAs/genética , MicroRNAs/imunologia , Antígeno B7-H1/imunologia , Estudos de Casos e Controles , Linhagem Celular , Vesículas Extracelulares/genética , Vesículas Extracelulares/imunologia , Vesículas Extracelulares/virologia , Feminino , Proteína Forkhead Box O1/genética , Proteína Forkhead Box O1/imunologia , Regulação da Expressão Gênica , Infecções por HIV/genética , HIV-1/imunologia , Humanos , Células Jurkat , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Masculino , Receptor de Morte Celular Programada 1/imunologia , Ativação Viral/genética , Ativação Viral/imunologia , Latência Viral/genética , Latência Viral/imunologiaRESUMO
BACKGROUND: T cell exhaustion compromises antitumor immunity, and a sustained elevation of co-inhibitory receptors is a hallmark of T cell exhaustion in solid tumors. Similarly, upregulation of co-inhibitory receptors has been reported in T cells in hematological cancers such as chronic lymphocytic leukemia (CLL). However, the role of CD160, a glycosylphosphatidylinositol-anchored protein, as one of these co-inhibitory receptors has been contradictory in T cell function. Therefore, we decided to elucidate how CD160 expression and/or co-expression with other co-inhibitory receptors influence T cell effector functions in patients with CLL. METHODS: We studied 56 patients with CLL and 25 age-matched and sex-matched healthy controls in this study. The expression of different co-inhibitory receptors was analyzed in T cells obtained from the peripheral blood or the bone marrow. Also, we quantified the properties of extracellular vesicles (EVs) in the plasma of patients with CLL versus healthy controls. Finally, we measured 29 different cytokines, chemokines or other biomarkers in the plasma specimens of patients with CLL and healthy controls. RESULTS: We found that CD160 was the most upregulated co-inhibitory receptor in patients with CLL. Its expression was associated with an exhausted T cell phenotype. CD160+CD8+ T cells were highly antigen-experienced/effector T cells, while CD160+CD4+ T cells were more heterogeneous. In particular, we identified EVs as a source of CD160 in the plasma of patients with CLL that can be taken up by T cells. Moreover, we observed a dominantly proinflammatory cytokine profile in the plasma of patients with CLL. In particular, interleukin-16 (IL-16) was highly elevated and correlated with the advanced clinical stage (Rai). Furthermore, we observed that the incubation of T cells with IL-16 results in the upregulation of CD160. CONCLUSIONS: Our study provides a novel insight into the influence of CD160 expression/co-expression with other co-inhibitory receptors in T cell effector functions in patients with CLL. Besides, IL-16-mediated upregulation of CD160 expression in T cells highlights the importance of IL-16/CD160 as potential immunotherapy targets in patients with CLL. Therefore, our findings propose a significant role for CD160 in T cell exhaustion in patients with CLL.
Assuntos
Antígenos CD/metabolismo , Leucemia Linfocítica Crônica de Células B/metabolismo , Linfócitos do Interstício Tumoral/metabolismo , Receptores Imunológicos/metabolismo , Linfócitos T/metabolismo , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Proliferação de Células , Células Cultivadas , Citocinas/sangue , Vesículas Extracelulares/imunologia , Vesículas Extracelulares/metabolismo , Feminino , Proteínas Ligadas por GPI/metabolismo , Humanos , Leucemia Linfocítica Crônica de Células B/imunologia , Ativação Linfocitária , Linfócitos do Interstício Tumoral/imunologia , Masculino , Pessoa de Meia-Idade , Fenótipo , Receptores de Antígenos de Linfócitos T/metabolismo , Transdução de Sinais , Linfócitos T/imunologiaRESUMO
SARS-CoV-2 infection is associated with lower blood oxygen levels, even in patients without hypoxia requiring hospitalization. This discordance illustrates the need for a more unifying explanation as to whether SARS-CoV-2 directly or indirectly affects erythropoiesis. Here, we show significantly enriched CD71+ erythroid precursors/progenitors in the blood circulation of COVID-19 patients. We found that these cells have distinctive immunosuppressive properties. In agreement, we observed a strong negative correlation between the frequency of these cells with T and B cell proportions in COVID-19 patients. The expansion of these CD71+ erythroid precursors/progenitors was negatively correlated with the hemoglobin levels. A subpopulation of abundant erythroid cells, CD45+ CD71+ cells, co-express ACE2, TMPRSS2, CD147, and CD26, and these can be infected with SARS-CoV-2. In turn, pre-treatment of erythroid cells with dexamethasone significantly diminished ACE2/TMPRSS2 expression and subsequently reduced their infectivity with SARS-CoV-2. This provides a novel insight into the impact of SARS-CoV-2 on erythropoiesis and hypoxia seen in COVID-19 patients.
Assuntos
Imunidade Adaptativa/imunologia , COVID-19/patologia , Células Precursoras Eritroides/virologia , Eritropoese/fisiologia , Hemoglobinas/análise , Oxigênio/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Enzima de Conversão de Angiotensina 2/metabolismo , Animais , Linfócitos B/citologia , Linfócitos B/imunologia , COVID-19/imunologia , Dexametasona/farmacologia , Células Precursoras Eritroides/imunologia , Feminino , Humanos , Contagem de Linfócitos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , SARS-CoV-2/imunologia , Serina Endopeptidases/metabolismo , Linfócitos T/citologia , Linfócitos T/imunologia , Adulto JovemRESUMO
Newborns are highly susceptible to infectious diseases. The underlying mechanism of neonatal infection susceptibility has generally been related to their under-developed immune system. Nevertheless, this notion has recently been challenged by the discovery of the physiological abundance of immunosuppressive erythroid precursors CD71+erythroid cells (CECs) in newborn mice and human cord blood. Here, as proof of concept, we show that these cells are also abundant in the peripheral blood of human newborns. Although their frequency appears to be more variable compared to their counterparts in mice, they rapidly decline by 4 weeks of age. However, their proportion remains significantly higher in infants up to six months of age compared to older infants. We found CD45 expressing CECs, as erythroid progenitors, were the prominent source of reactive oxygen species (ROS) production in both humans and mice. Interestingly, a higher proportion of CD45+CECs was observed in the spleen versus bone marrow of neonatal mice, which was associated with a higher ROS production by splenic CECs compared to their siblings in the bone marrow. CECs from human newborns suppressed cytokine production by CD14 monocytes and T cells, which was partially abrogated by apocynin in vitro. Moreover, the depletion of CECs in neonatal mice increased the number of activated effector immune cells in their spleen and liver, which rendered them more resistant to Listeria monocytogenes infection. This was evident by a significant reduction in the bacteria load in the spleen, liver and brain of treated-mice compared to the control group, which enhanced their survival rate. Our finding highlights the immunoregulatory processes mediated by CECs in newborns. Thus, such tightly regulated immune system in newborns/infants may explain one potential mechanism for the asymptomatic or mild COVID-19 infection in this population.
Assuntos
Antígenos CD/imunologia , Células Precursoras Eritroides , Terapia de Imunossupressão , Listeria monocytogenes/imunologia , Listeriose , Receptores da Transferrina/imunologia , Animais , Animais Recém-Nascidos , COVID-19/imunologia , COVID-19/patologia , Células Precursoras Eritroides/imunologia , Células Precursoras Eritroides/patologia , Células Precursoras Eritroides/transplante , Feminino , Xenoenxertos , Humanos , Recém-Nascido , Listeriose/imunologia , Listeriose/patologia , Listeriose/terapia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , SARS-CoV-2/imunologiaRESUMO
BACKGROUND: In addition to cognitive decline, Alzheimer's Disease (AD) is also characterized by agitation and disruptions in activity and sleep. These symptoms typically occur in the evening or night and have been referred to as 'sundowning'. They are especially difficult for carers and there are no specific drug treatments. There is increasing evidence that these symptoms reflect pathology of circadian rhythm generation and transmission. OBJECTIVE: We investigated whether a transgenic mouse model relevant to AD (APPswe/PS1dE9) exhibits circadian alterations in locomotor activity in their home cage and whether expression of clock genes involved in the regulation of the circadian cycle is abnormal in the hippocampus and medulla-pons brain regions isolated from these mice. RESULTS: In 2month old female mice the APPswe/PS1dE9 transgene alters levels and patterns in circadian rhythm of locomotor activity. Expression of the clock genes Per1, Per2, Cry1 and Cry2 was found to increase at night compared to day in wild-type control mice in the medulla/pons. This effect was blunted for Cry1 and Cry2 gene expression in APPswe/PS1dE9. CONCLUSION: This study suggests altered circadian regulation of locomotor activity is abnormal in female APPswe/ PS1dE9 mice and that this alteration has biomolecular analogies in a widely available model of AD. The early age at which these effects are manifest suggests that these circadian effects may precede plaque development. The APPswe/PS1dE9 mouse genetic model may have potential to serve as a tool in understanding the neuropathology of circadian abnormalities in AD and as a model system to test novel therapeutic agents for these symptoms.