RESUMO
Humans are exposed every day to innumerable external stimuli, both environmental and microbial. Immunological memory recalls each specific stimulus and mounts a secondary response that is faster and of a larger magnitude than the primary response; this process constitutes the basis for vaccine development. The COVID-19 pandemic offers a unique opportunity to study the development of immune memory against an emergent microorganism. Memory T cells have an important role in the resolution of COVID-19, and they are key pillars of immunological memory. In this review, we summarize the main findings regarding anti-SARS-CoV-2 memory T cells after infection, after vaccination, and after the combination of these two events ("hybrid immunity"), and analyze how these cells can contribute to long-term protection against the infection with SARS-CoV-2 variants.
Los humanos se exponen cada día a innumerables estímulos externos, tanto ambientales como microbianos. La memoria inmunológica registra de manera específica un estímulo y articula una respuesta secundaria más rápida y de mayor magnitud que la respuesta primaria; este proceso constituye la base del desarrollo de vacunas. La pandemia de COVID-19 ofreció la oportunidad de estudiar el desarrollo de la memoria inmunológica contra un microorganismo emergente. Las células T de memoria tienen un papel importante en la resolución de COVID-19 y son pilares importantes de la memoria inmunológica. En esta revisión se resumen los principales hallazgos de la respuesta de las células T de memoria contra la infección por SARS-CoV-2, a la vacunación o a la combinación de ambos procesos ("inmunidad híbrida"), y se discute cómo estas células pueden contribuir a la protección a largo plazo contra distintas variantes del virus.
Assuntos
Vacinas contra COVID-19 , COVID-19 , Memória Imunológica , Células T de Memória , SARS-CoV-2 , Humanos , COVID-19/imunologia , COVID-19/prevenção & controle , Memória Imunológica/imunologia , Células T de Memória/imunologia , Vacinas contra COVID-19/imunologia , SARS-CoV-2/imunologiaRESUMO
HIV-1 infection greatly alters the NK cell phenotypic and functional repertoire. This is highlighted by the expansion of a rare population of FcRγ- NK cells exhibiting characteristics of traditional immunologic memory in people with HIV (PWH). Although current antiretroviral therapy (ART) effectively controls HIV-1 viremia and disease progression, its impact on HIV-1-associated NK cell abnormalities remains unclear. To address this, we performed a longitudinal analysis detailing conventional and memory-like NK cell characteristics in n = 60 PWH during the first 4 y of ART. Throughout this regimen, a skewed repertoire of cytokine unresponsive FcRγ- memory-like NK cells persisted and accompanied an overall increase in NK surface expression of CD57 and KLRG1, suggestive of progression toward immune senescence. These traits were linked to elevated serum inflammatory biomarkers and increasing Ab titers to human CMV, with human CMV viremia detected in approximately one-third of PWH at years 1-4 of ART. Interestingly, 40% of PWH displayed atypical NK cell subsets, representing intermediate stages of NK-poiesis based on single-cell multiomic trajectory analysis. Our findings indicate that NK cell irregularities persist in PWH despite long-term ART, underscoring the need to better understand the causative mechanisms that prevent full restoration of immune health in PWH.
Assuntos
Antígenos CD57 , Infecções por HIV , HIV-1 , Células Matadoras Naturais , Humanos , Células Matadoras Naturais/imunologia , Infecções por HIV/imunologia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , HIV-1/imunologia , Masculino , Feminino , Antígenos CD57/imunologia , Adulto , Pessoa de Meia-Idade , Memória Imunológica/imunologia , Lectinas Tipo C/imunologia , Receptores Imunológicos , Viremia/imunologia , Viremia/tratamento farmacológico , Infecções por Citomegalovirus/imunologia , Infecções por Citomegalovirus/tratamento farmacológico , Receptores de IgG/imunologia , Estudos Longitudinais , Antirretrovirais/uso terapêuticoRESUMO
The induction of trained immunity represents an emerging concept defined as the ability of innate immune cells to acquire a memory phenotype, which is a typical hallmark of the adaptive response. Key points modulated during the establishment of trained immunity include epigenetic, metabolic and functional changes in different innate-immune and non-immune cells. Regarding to epigenetic changes, it has been described that long non-coding RNAs (LncRNAs) act as molecular scaffolds to allow the assembly of chromatin-remodeling complexes that catalyze epigenetic changes on chromatin. On the other hand, relevant metabolic changes that occur during this process include increased glycolytic rate and the accumulation of metabolites from the tricarboxylic acid (TCA) cycle, which subsequently regulate the activity of histone-modifying enzymes that ultimately drive epigenetic changes. Functional consequences of established trained immunity include enhanced cytokine production, increased antigen presentation and augmented antimicrobial responses. In this article, we will discuss the current knowledge regarding the ability of different cell subsets to acquire a trained immune phenotype and the molecular mechanisms involved in triggering such a response. This knowledge will be helpful for the development of broad-spectrum therapies against infectious diseases based on the modulation of epigenetic and metabolic cues regulating the development of trained immunity.
Assuntos
Interações Hospedeiro-Patógeno/imunologia , Imunidade Celular , Imunidade Inata/imunologia , Memória Imunológica/imunologia , Imunidade Adaptativa/genética , Imunidade Adaptativa/imunologia , Imunidade Adaptativa/fisiologia , Animais , Vacina BCG/imunologia , Brônquios/citologia , Brônquios/imunologia , Citocinas/fisiologia , Metabolismo Energético , Epigênese Genética , Células Epiteliais/imunologia , Trato Gastrointestinal/citologia , Trato Gastrointestinal/imunologia , Células-Tronco Hematopoéticas/imunologia , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/fisiologia , Humanos , Imunidade Celular/genética , Imunidade Celular/fisiologia , Imunidade Inata/genética , Imunidade Inata/fisiologia , Memória Imunológica/genética , Memória Imunológica/fisiologia , Linfócitos/imunologia , Camundongos , Células Mieloides/imunologia , NAD/fisiologia , Pele/citologia , Pele/imunologiaRESUMO
The cellular immune response plays an important role in COVID-19, caused by SARS-CoV-2. This feature makes use of in vitro models' useful tools to evaluate vaccines and biopharmaceutical effects. Here, we developed a two-step model to evaluate the cellular immune response after SARS-CoV-2 infection-induced or spike protein stimulation in peripheral blood mononuclear cells (PBMC) from both unexposed and COVID-19 (primo-infected) individuals (Step1). Moreover, the supernatants of these cultures were used to evaluate its effects on lung cell lines (A549) (Step2). When PBMC from the unexposed were infected by SARS-CoV-2, cytotoxic natural killer and nonclassical monocytes expressing inflammatory cytokines genes were raised. The supernatant of these cells can induce apoptosis of A549 cells (mock vs. Step2 [mean]: 6.4% × 17.7%). Meanwhile, PBMCs from primo-infected presented their memory CD4+ T cells activated with a high production of IFNG and antiviral genes. Supernatant from past COVID-19 subjects contributed to reduce apoptosis (mock vs. Step2 [ratio]: 7.2 × 1.4) and to elevate the antiviral activity (iNOS) of A549 cells (mock vs. Step2 [mean]: 31.5% × 55.7%). Our findings showed features of immune primary cells and lung cell lines response after SARS-CoV-2 or spike protein stimulation that can be used as an in vitro model to study the immunity effects after SARS-CoV-2 antigen exposure.
Assuntos
COVID-19/imunologia , COVID-19/virologia , Imunidade Celular , Modelos Biológicos , SARS-CoV-2/fisiologia , Adulto , Células Epiteliais Alveolares/virologia , COVID-19/sangue , COVID-19/genética , Citocinas/genética , Citocinas/metabolismo , Feminino , Regulação da Expressão Gênica , Humanos , Memória Imunológica/imunologia , Células Matadoras Naturais/imunologia , Leucócitos Mononucleares/virologia , Masculino , Pessoa de Meia-Idade , Fenótipo , Linfócitos T/imunologia , Replicação Viral/fisiologia , Adulto JovemRESUMO
Repetitive exposure of Rag1-/- mice to the Alternaria allergen extract generated a form of memory that elicited an asthma-like response upon a subthreshold recall challenge 3-15 wk later. This memory was associated with lung ICOS+ST2+ ILC2s. Genetic, pharmacologic, and antibody-mediated inhibition and adoptive transfer established an essential role for ILC2s in memory-driven asthma. ATAC-seq demonstrated a distinct epigenetic landscape of memory ILC2s and identified Bach2 and AP1 (JunD and Fosl2) motifs as major drivers of altered gene accessibility. scRNA-seq, gene knockout, and signaling studies suggest that repetitive allergenic stress induces a gene repression program involving Nr4a2, Zeb1, Bach2, and JunD and a preparedness program involving Fhl2, FosB, Stat6, Srebf2, and MPP7 in memory ILC2s. A mutually regulated balance between these two programs establishes and maintains memory. The preparedness program (e.g., Fhl2) can be activated with a subthreshold cognate stimulation, which down-regulates repressors and activates effector pathways to elicit the memory-driven phenotype.
Assuntos
Asma/imunologia , Epigênese Genética/imunologia , Imunidade Inata/imunologia , Memória Imunológica/imunologia , Linfócitos/imunologia , Transferência Adotiva/métodos , Alérgenos/imunologia , Alternaria/imunologia , Animais , Regulação para Baixo/imunologia , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos KnockoutRESUMO
Patients with rheumatoid arthritis (RA) may be classified as seropositive or seronegative according to the presence of autoantibodies. An abnormal B cell phenotype and function could be one of the main components of the immunopathology of seropositive patients; however, there is little information regarding B cell defects in these patients. This study shows a broad characterization of the B cell phenotype and function in patients with seropositive RA. We focused mainly on the evaluation of subsets, the expression of modulatory molecules of cell activation (CD22, FcÉ£RIIb and FcµR), calcium mobilization, global tyrosine phosphorylation, expression of activation markers, cytokine and immunoglobulin (Ig) production, proliferation and the in-vitro generation of plasma cells. Increased frequency of CD27- IgM- IgD- and CD21- B cells was observed in patients with seropositive RA compared with healthy donors (HD). Decreased expression of CD22 was primarily found in memory B cells of patients with RA regardless of seropositivity. B cells from seropositive patients exhibited normal proliferation, calcium mobilization kinetics and global tyrosine phosphorylation, but showed an increased frequency of CD86+ B cells compared with HD. B cells of seropositive patients secrete less interleukin-10 after in-vitro activation and showed a decreased frequency of plasma cell differentiation and IgM production compared with HD. Our data indicate that patients with seropositive RA have an increased frequency of atypical B cell populations previously associated with chronic activation and antigen exposure. This may result in the observed low responsiveness of these cells in vitro.
Assuntos
Artrite Reumatoide/imunologia , Linfócitos B/imunologia , Adulto , Idoso , Autoanticorpos/imunologia , Diferenciação Celular/imunologia , Citocinas/imunologia , Feminino , Humanos , Isotipos de Imunoglobulinas/imunologia , Memória Imunológica/imunologia , Ativação Linfocitária/imunologia , Masculino , Pessoa de Meia-Idade , FenótipoRESUMO
Immunotherapy has improved the clinical response in melanoma patients, although a relevant percentage of patients still cannot be salvaged. The search for the immune populations that provide the best tumor control and that can be coaxed by immunotherapy strategies is a hot topic in cancer research nowadays. Tumor-infiltrating TCF-1+ progenitor exhausted CD8+ T cells seem to grant the best melanoma prognosis and also efficiently respond to anti-PD-1 immunotherapy, giving rise to a TIM-3+ terminally exhausted population with heightened effector activity. We tested Porins from Salmonella Typhi as a pathogen associated molecular pattern adjuvant of natural or model antigen in prophylactic and therapeutic immunization approaches against murine melanoma. Porins induced protection against melanomas, even upon re-challenging of tumor-free mice. Porins efficiently expanded IFN-γ-producing CD8+ T cells and induced central and effector memory in lymph nodes and tissue-resident (Trm) T cells in the skin and tumors. Porins induced TCF-1+ PD-1+ CD8+ Trm T cells in the tumor stroma and the presence of this population correlated with melanoma growth protection in mice. Porins immunization also cooperated with anti-PD-1 immunotherapy to hamper melanoma growth. Importantly, the potentially protective Trm populations induced by Porins in the murine model were also observed in melanoma patients in which their presence also correlated with disease control. Our data support the use of cancer vaccination to sculpt the tumor stroma with efficient and lasting Trm T cells with effector activities, highlighting the use of Porins as an adjuvant. Furthermore, our data place CD8+ Trm T cells with a progenitor exhausted phenotype as an important population for melanoma control, either independently or in cooperation with anti-PD-1 immunotherapy.
Assuntos
Adjuvantes Imunológicos/farmacologia , Linfócitos T CD8-Positivos/imunologia , Vacinas Anticâncer/imunologia , Melanoma/imunologia , Porinas/imunologia , Animais , Proteínas de Bactérias/imunologia , Proteínas de Bactérias/farmacologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Vacinas Anticâncer/farmacologia , Humanos , Inibidores de Checkpoint Imunológico/farmacologia , Imunização , Memória Imunológica/efeitos dos fármacos , Memória Imunológica/imunologia , Imunoterapia/métodos , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Linfócitos do Interstício Tumoral/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Porinas/farmacologia , Salmonella typhiRESUMO
Zika virus appeared in South America in 2015, generating alarm worldwide as it causes microcephaly and autoimmunity. This study aims to determine the serological footprint of the incoming epidemic in a student community and to characterize the memory functional cell response during post convalescence. In a cross-sectional study, Zika-specific IgG using LIA immunoassay was found in 328 university students (CI=95%), while in the second phase, the functional cellular memory response for IFN-γ and IL-2 was quantified using post-stimulus ELISpot with inactivated virus, starting with individuals seropositive for Zika and control individuals (seropositive only for Dengue and seronegative for Zika-Dengue). Depending on the antigen used, memory humoral response (IgG) against Zika Virus was observed in >60% of the population; seropositivity for NS1 was 21.1% higher than E antigen with high intensity. The analysis of cell functionality in 22 individuals seropositive for Zika virus revealed either IFN-γ+ or IL-2+ cells in 86.3% of cases (Th1 profile), presenting multifunctionality in 50% (11 individuals), 64% of which presented> 6 SFC/104 PBMCs (>600 SFC/106 PBMC), reflecting memory circulating cells. A good agreement (Kappa= 0.754) was observed between the coexistence of both cellular and humoral responses but not in their intensity.
Assuntos
Anticorpos Antivirais/sangue , Memória Imunológica/imunologia , Infecção por Zika virus/virologia , Zika virus/imunologia , Adolescente , Adulto , Anticorpos Antivirais/imunologia , Colômbia , Estudos Transversais , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudantes , Universidades , Adulto Jovem , Infecção por Zika virus/imunologiaRESUMO
Melanoma is an aggressive form of skin-cancer. Melanoma cells are characterized by their plasticity, resulting in therapy resistance. Using RET transgenic mouse melanoma model, we characterized dormant tumor cells accumulated in the bone marrow (BM) and investigated their interaction with effector memory CD8+ T cells. We found that cells expressing melanoma-associated antigen tyrosinase related protein (TRP)-2 and stemness marker CD133 represented less than 1.5% of all melanoma cells in primary skin lesions and metastatic lymph nodes. The majority of these cells were negative for the proliferation marker Ki67. In the BM, CD133+TRP-2+ melanoma cells displayed an aberrant expression of p16, p27, Ki67 and PCNA proteins, suggesting their dormant phenotype. Moreover, these cells were characterized by an elevated expression of various molecules characterized stemness, metastatic, angiogenic and immunosuppressive properties such as CD271, CD34, HIF-1α, CXCR3, CXCR4, VEGR2, PD-L1, CTLA-4, CD39 and CCR4 as compared to their CD133- counterparts. Disseminated BM dormant TRP-2+ tumor cells were found to be co-localized with memory CD8+ T cells. Our data suggest that these dormant melanoma cells in the BM could play an important role in the maintenance of memory T cells in the BM.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Modelos Animais de Doenças , Memória Imunológica/imunologia , Linfonodos/imunologia , Melanoma/imunologia , Proteínas Proto-Oncogênicas c-ret/genética , Linfócitos T Reguladores/imunologia , Animais , Linfócitos T CD8-Positivos/patologia , Humanos , Melanoma/genética , Melanoma/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas Proto-Oncogênicas c-ret/metabolismoRESUMO
For many years, the immune response of invertebrates was considered to lack any mechanism of memory. However, the study of their response has shown a kind of acquired immunity, which is not so well understood given the lack of knowledge of the invertebrate defense system. This event can be called "innate immune memory." Recent studies using Biomphalaria glabrata snails have reported this phenomenon, relating it to an increase in humoral products, but no focus was given to hemocyte response or to other species of snails. In this study, we focus on hemocyte dynamics and some humoral factors in the species B. glabrata and B. straminea, the most widespread species in Brazil, sensitized and non-sensitized to the Schistosoma mansoni worm. We report a change in the prevalent hemocyte type after sensitization, through an increase in the proportion of granulocytes, as well as a change in the total number of hemocytes caused by a second exposure to the parasite. We also showed that melanization is not a key factor in Biomphalaria snail defense and varies little after the second exposure event. The data reported in this article confirm the effect of immune priming on these snails and suggest that the increase of humoral products shown in the literature is accompanied by variation in hemocytes after sensitization.