RESUMO
Lung transplant remains the primary therapeutic option for patients with end-stage lung disease, but long-term survival rates remain suboptimal compared with other solid organ transplants. Acute cellular rejection (ACR) is a significant challenge in lung transplant recipients, with T cell-mediated mechanisms playing a major role. IL-10 is known for its immunoregulatory function, although its specific role in lung allograft rejection remains unclear. Using the mouse orthotopic lung transplant model, we investigated the role of IL-10 in regulating alloeffector T cell responses. Unexpectedly, we found that IL-10 was not required for early costimulation blockade-induced allograft acceptance. However, IL-10 deficiency or blockade resulted in increased CD4+ T cell numbers, proliferation, graft infiltration, and alloeffector responses. In the absence of IL-10, CD4+ T cell responses predominated over CD8 responses during ACR in contrast to wild-type mice. Type 1 immunity (IFN-γ) responses along with elevated CD4+NKG7+ and CD4+CD107a+ responses predominated during ACR, highlighting a critical regulatory role for IL-10 in modulating CD4+ T cell alloimmune responses. We further demonstrated increased colocalization of NKG7 and CD107a in CD4+ T cells from IL-10-deficient allografts, suggesting coordination in cytotoxic activity. Together, our findings highlight a critical role for IL-10 in regulation of cytotoxic CD4+NKG7+ T cells, an effector population that needs further investigation to elucidate their role in lung allograft rejection.
Assuntos
Aloenxertos , Rejeição de Enxerto , Interleucina-10 , Transplante de Pulmão , Animais , Camundongos , Aloenxertos/imunologia , Linfócitos T CD4-Positivos/imunologia , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Interferon gama/imunologia , Interferon gama/metabolismo , Interleucina-10/imunologia , Interleucina-10/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Linfócitos T Citotóxicos/imunologiaRESUMO
ABSTRACT: Cytotoxic T lymphocytes (CTLs) destroy virally infected cells and are critical for the elimination of viral infections such as those caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Delayed and dysfunctional adaptive immune responses to SARS-CoV-2 are associated with poor outcomes. Treatment with allogeneic SARS-CoV-2-specific CTLs may enhance cellular immunity in high-risk patients providing a safe, direct mechanism of treatment. Thirty high-risk ambulatory patients with COVID-19 were enrolled in a phase 1 trial assessing the safety of third party, SARS-CoV-2-specific CTLs. Twelve interventional patients, 6 of whom were immunocompromised, matched the HLA-A∗02:01 restriction of the CTLs and received a single infusion of 1 of 4 escalating doses of a product containing 68.5% SARS-CoV-2-specific CD8+ CTLs/total cells. Symptom improvement and resolution in these patients was compared with an observational group of 18 patients lacking HLA-A∗02:01 who could receive standard of care. No dose-limiting toxicities were observed at any dosing level. Nasal swab polymerase chain reaction testing showed ≥88% and >99% viral elimination from baseline in all patients at 4 and 14 days after infusion, respectively. The CTLs did not interfere with the development of endogenous anti-SARS-CoV-2 humoral or cellular responses. T-cell receptor ß analysis showed persistence of donor-derived SARS-CoV-2-specific CTLs through the end of the 6-month follow-up period. Interventional patients consistently reported symptomatic improvement 2 to 3 days after infusion, whereas improvement was more variable in observational patients. SARS-CoV-2-specific CTLs are a potentially feasible cellular therapy for COVID-19 illness. This trial was registered at www.clinicaltrials.gov as #NCT04765449.
Assuntos
COVID-19 , SARS-CoV-2 , Linfócitos T Citotóxicos , Humanos , COVID-19/imunologia , COVID-19/terapia , Linfócitos T Citotóxicos/imunologia , Pessoa de Meia-Idade , Masculino , SARS-CoV-2/imunologia , Feminino , Idoso , Adulto , Estudos de Viabilidade , Imunoterapia Adotiva/efeitos adversos , Imunoterapia Adotiva/métodos , Resultado do Tratamento , Antígeno HLA-A2/imunologiaRESUMO
Yellow fever outbreaks are prevalent, particularly in endemic regions. Given the lack of an established treatment for this disease, significant attention has been directed toward managing this arbovirus. In response, we developed a multiepitope vaccine designed to elicit an immune response, utilizing advanced immunoinformatic and molecular modeling techniques. To achieve this, we predicted B- and T-cell epitopes using the sequences from all structural (E, prM, and C) and nonstructural proteins of 196 YFV strains. Through comprehensive analysis, we identified 10 cytotoxic T-lymphocyte (CTL) and 5T-helper (Th) epitopes that exhibited overlap with B-lymphocyte epitopes. These epitopes were further evaluated for their affinity to a wide range of human leukocyte antigen system alleles and were rigorously tested for antigenicity, immunogenicity, allergenicity, toxicity, and conservation. These epitopes were linked to an adjuvant ( ß -defensin) and to each other using ligands, resulting in a vaccine sequence with appropriate physicochemical properties. The 3D structure of this sequence was created, improved, and quality checked; then it was anchored to the Toll-like receptor. Molecular Dynamics and Quantum Mechanics/Molecular Mechanics simulations were employed to enhance the accuracy of docking calculations, with the QM portion of the simulations carried out utilizing the density functional theory formalism. Moreover, the inoculation model was able to provide an optimal codon sequence that was inserted into the pET-28a( +) vector for in silico cloning and could even stimulate highly relevant humoral and cellular immunological responses. Overall, these results suggest that the designed multi-epitope vaccine can serve as prophylaxis against the yellow fever virus.
Assuntos
Epitopos de Linfócito T , Vacina contra Febre Amarela , Febre Amarela , Vírus da Febre Amarela , Vacina contra Febre Amarela/imunologia , Vírus da Febre Amarela/imunologia , Vírus da Febre Amarela/genética , Humanos , Febre Amarela/prevenção & controle , Febre Amarela/imunologia , Epitopos de Linfócito T/imunologia , Epitopos de Linfócito B/imunologia , Vacinologia/métodos , Modelos Moleculares , Desenvolvimento de Vacinas , Simulação de Dinâmica Molecular , Linfócitos T Citotóxicos/imunologiaRESUMO
BACKGROUND/AIM: Liver metastases are among the principal mortality causes in cancer patients. Dendritic cell immunotherapies have shown promising results in some tumors by mediating immunological mechanisms that could be involved in liver metastases during primary tumor growth. The present study aimed to evaluate the impact of prophylactic dendritic cell vaccination on the liver of mice with 4T1 mouse breast carcinoma. MATERIALS AND METHODS: Adult female Balb/c mice were submitted or not to vaccination with dendritic cells before the induction of 4T1 tumor lineage. Liver tissues from mice were analyzed by flow cytometry (markers CD3, CD4, CD8, CD25, IL-10, IL-12, IL-17, TNF-α, IFN-γ, T-bet, GATA3, RORγt, and FoxP3) and hematoxylin-eosin. The dendritic cell vaccine was differentiated and matured ex vivo from the bone marrow. RESULTS: Prophylactic vaccination reduced areas of liver metastases (p=0.0049), induced an increase in the percentage of total T and cytotoxic T lymphocytes (p<0.0001), as well as FoxP3+ (p<0.0001). It also increased the levels of cytokines IL-10 and IL-17 in helper T lymphocytes (p<0.0001). CONCLUSION: The prophylactic dendritic cell vaccine changed the cell phenotype in the immune response of liver, and it was able to reduce metastases. Cytotoxic T cells and regulatory T lymphocytes were more present, likewise, the production of IL-10 and IL-7 simultaneously, demonstrating that the vaccine can induce a state of control of pro-inflammatory responses, which can provide a less favorable environment for metastatic tumor growth.
Assuntos
Neoplasias da Mama/imunologia , Vacinas Anticâncer/imunologia , Células Dendríticas/imunologia , Neoplasias Hepáticas/imunologia , Fígado/imunologia , Animais , Biomarcadores Tumorais/imunologia , Medula Óssea/imunologia , Neoplasias da Mama/patologia , Modelos Animais de Doenças , Feminino , Imunidade/imunologia , Imunoterapia/métodos , Fígado/patologia , Neoplasias Hepáticas/patologia , Camundongos , Camundongos Endogâmicos BALB C , Linfócitos T Citotóxicos/imunologia , Linfócitos T Reguladores/imunologia , Vacinação/métodosRESUMO
The immune response is critical in NAFLD pathogenesis, but the liver infiltrate's composition and the role of each T cell population is still up for debate. To characterize liver pathogenesis in pediatric and adult cases, frequency and localization of immune cell populations [Cytotoxic T Lymphocytes (CD8+), T helper Lymphocytes (CD4+), Regulatory T lymphocytes (Foxp3+) and Th17 (IL-17A+)] were evaluated. In portal/periportal (P/P) tracts, both age groups displayed a similar proportion of CD8+ and CD4+ lymphocytes. However, comparable Foxp3+ and IL-17A+ cell frequencies were observed in pediatric cases, meanwhile, in adults Foxp3+ was higher than IL-17A+ cells. Interestingly, IL-17A+ lymphocytes seemed to be nearly exclusive of P/P area in both age groups. In intralobular areas, both pediatric and adult cases showed CD8+ lymphocytes predominance with lower frequencies of CD4+ lymphocytes followed by Foxp3+ . Severe inflammation was associated with higher intralobular Foxp3+ lymphocytes (p = 0.026) in children, and lower P/P Foxp3+ and higher IL-17A+ lymphocytes in adults. All cases with fibrosis ≥ 2 displayed P/P low Foxp3+ and high IL-17A+ lymphocyte counts. Pediatric cases with worse steatosis showed high P/P CD4+ (p = 0.023) and intralobular CD8+ (p = 0.027) and CD4+ cells (p = 0.012). In NAFLD cases, the lymphocyte liver infiltrate composition differs between histological areas. Treg and Th17 balance seems to condition damage progression, denoting their important role in pathogenesis.
Assuntos
Linhagem da Célula/imunologia , Fígado/imunologia , Hepatopatia Gordurosa não Alcoólica/genética , Linfócitos T/imunologia , Adolescente , Adulto , Idoso , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Linhagem da Célula/genética , Criança , Pré-Escolar , Feminino , Fatores de Transcrição Forkhead/genética , Humanos , Interleucina-17/genética , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/imunologia , Hepatopatia Gordurosa não Alcoólica/patologia , Pediatria , Linfócitos T/patologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/patologia , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/patologia , Células Th1/imunologia , Células Th1/patologiaRESUMO
Gap junctions (GJs) are clusters of intercellular connexin-formed channels found at the plasma membrane that allow direct communication between the cytoplasm of adjacent cells. Numerous reports have described GJs as modulators of key immunological processes, including in anti-tumor immune responses. Here, we described a simple flow cytometry method to test in vitro antigen-dependent GJ-mediated cell-to-cell coupling between cytotoxic T cells and target melanoma cells.
Assuntos
Comunicação Celular/imunologia , Junções Comunicantes/imunologia , Melanoma/imunologia , Linfócitos T Citotóxicos/imunologia , Junções Comunicantes/patologia , Humanos , Melanoma/patologia , Linfócitos T Citotóxicos/patologiaRESUMO
During the acute phase of HIV-1 infection, a strong readaptation occurs in the viral population. Our objective was to analyze the post-transmission mutations associated with escape to the cytotoxic immune response and its relationship with the progression of the infection. In this study, a total of 17 patients were enrolled during acute/early primary HIV infection and 8 subjects that were the HIV positive partner resulting in 8 transmission pairs. Genotyping of the genetic polymorphisms of HLA class I A and B was performed using PCR-SSOP. Viral RNA extraction was from plasma. 570 single Gag-gene amplifications were obtained by limiting-dilution RT-PCR. Epitope prediction was performed with NetMHC CBS prediction server for the 19 HLA-A and B alleles. Cytotoxic response prediction was performed by using the IEDB Analysis Resource. From our results, we deduce that the transmitted CTL / gag escape frequency in the founder virus was at least double compared to the post-transmission events. Additionally, by means of an algorithm that combines these frequencies, we observed that the founder viruses better adapted to the HLA A / B alleles of the recipient could contribute to a greater progression of the infection. Our results suggest that there is a large adaptation of HIV-1 to the HLA A / B alleles prevalent in our population. However, despite this adaptive advantage, the virus needs to make "readjustments" through new escape and compensatory mutations. Interestingly, according to our results, this readaptation could have a role in the progression of the infection.
Assuntos
Infecções por HIV/virologia , HIV-1/genética , Adulto , Alelos , Argentina , Biologia Computacional , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Feminino , Genótipo , Infecções por HIV/imunologia , HIV-1/imunologia , Humanos , Masculino , Mutação/genética , Mutação/imunologia , RNA Viral/genética , RNA Viral/imunologia , Linfócitos T Citotóxicos/imunologia , Produtos do Gene gag do Vírus da Imunodeficiência Humana/genética , Produtos do Gene gag do Vírus da Imunodeficiência Humana/imunologiaRESUMO
Cytotoxic activity mediated by CD8+ T cells is the main signature of the immunopathogenesis of cutaneous leishmaniasis (CL). Here, we performed a broad evaluation of natural killer (NK) cell phenotypic and functional features during cutaneous leishmaniasis. We demonstrate for the first time that CL patients present the accumulation of circulating NK cells with multiple features of replicative senescence including low proliferative capacity and shorter telomeres, elevated expression of CD57, KLRG1 but diminished CD27 stimulatory receptor expression. Moreover, they exhibited higher cytotoxic and inflammatory potential than age-matched controls. The accumulation of circulating senescent NK cells (CD56dim CD57bright ) correlated positively with skin lesion size in the same patients, suggesting that they, like circulating senescent CD8+ T cells, may contribute to the immunopathology of CL. However, this senescent population had lower cutaneous lymphocyte antigen expression and so had diminished skin-homing potential compared with total or senescent CD8+ T cells. This was confirmed in CL skin lesions where we found a predominance of CD8+ T cells (both senescent and non-senescent) that correlated with the severity of the disease. Although there was also a correlation between the proportions of senescent NK cells (CD56+ CD57+ ) in the skin and lesion size, this was less evident. Collectively our results demonstrate first-hand that senescent cytotoxic cells may mediate skin pathology during human cutaneous leishmaniasis. However, as senescent cytotoxic CD8+ T cells predominate in the skin lesions, they may have a greater role than NK cells in mediating the non-specific skin damage in CL.
Assuntos
Citotoxicidade Imunológica , Células Matadoras Naturais/patologia , Leishmania braziliensis/patogenicidade , Leishmaniose Cutânea/patologia , Pele/patologia , Linfócitos T Citotóxicos/patologia , Antígeno CD56/genética , Antígeno CD56/imunologia , Antígenos CD57/genética , Antígenos CD57/imunologia , Estudos de Casos e Controles , Senescência Celular/imunologia , Feminino , Regulação da Expressão Gênica , Interações Hospedeiro-Parasita/genética , Interações Hospedeiro-Parasita/imunologia , Humanos , Interferon gama/genética , Interferon gama/imunologia , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/parasitologia , Lectinas Tipo C/genética , Lectinas Tipo C/imunologia , Leishmania braziliensis/imunologia , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/parasitologia , Masculino , Oligossacarídeos/genética , Oligossacarídeos/imunologia , Receptores Imunológicos/genética , Receptores Imunológicos/imunologia , Índice de Gravidade de Doença , Antígeno Sialil Lewis X/análogos & derivados , Antígeno Sialil Lewis X/genética , Antígeno Sialil Lewis X/imunologia , Transdução de Sinais , Pele/imunologia , Pele/parasitologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/parasitologiaRESUMO
Upon tumor antigen recognition, cytotoxic T lymphocytes (CTLs) and target cells form specialized supramolecular structures, called cytotoxic immunological synapses, which are required for polarized delivery of cytotoxic granules. In previous reports, we described the accumulation of connexin 43 (Cx43)-formed gap junctions (GJs) at natural killer (NK) cell-tumor cell cytotoxic immunological synapse. In this report, we demonstrate the functional role of Cx43-GJs at the cytotoxic immunological synapse established between CTLs and melanoma cells during cytotoxicity. Using confocal microscopy, we evaluated Cx43 polarization to the contact site between CTLs isolated from pMEL-1 mice and B16F10 melanoma cells. We knocked down Cx43 expression in B16F10 cells and evaluated its role in the formation of functional GJs and the cytotoxic activity of CTLs, by calcein transfer and granzyme B activity assays, respectively. We found that Cx43 localizes at CTL/B16F10 intercellular contact sites via an antigen-dependent process. We also found that pMEL-1 CTLs but not wild-type naïve CD8+ T cells established functional GJs with B16F10 cells. Interestingly, we observed that Cx43-GJs were required for an efficient granzyme B activity in target B16F10 cells. Using an HLA-A2-restricted/MART-1-specific CD8+ T-cell clone, we confirmed these observations in human cells. Our results suggest that Cx43-channels are relevant components of cytotoxic immunological synapses and potentiate CTL-mediated tumor cell killing.
Assuntos
Conexina 43/imunologia , Junções Comunicantes/imunologia , Sinapses Imunológicas/imunologia , Melanoma/imunologia , Linfócitos T Citotóxicos/imunologia , Animais , Linhagem Celular Tumoral , Citotoxicidade Imunológica , Junções Comunicantes/patologia , Humanos , Sinapses Imunológicas/patologia , Melanoma/patologia , Camundongos Endogâmicos C57BL , Linfócitos T Citotóxicos/patologiaRESUMO
Introduction: The immunological role of plasmacytoid dendritic cells (pDC) in bacterial infections such as Salmonella has been poorly documented. Therefore, we analyzed the effector function of these cells by presenting cytotoxic T lymphocytes (CTL) with Salmonella Typhimurium antigens. Objective: To analyze the Salmonella-specific CTL response evoked by pDCs. Materials and methods: We used plasmacytoid dendritic cells stained with carboxyfluorescein succinimidyl ester (CFSE) and pulsed with OmpC73, Salmonella Kb restricted epitopes or S. Typhimurium as targets for cytotoxicity assays. Results: Specific lysis was shown to be statistically significant in pDC + OmpC73 for all effector:target ratios (p≤0.05). For pDC + S. Typhimurium, statistical significance was only observed at a 1:100 ratio (p≤0.05) using OmpC73. Conclusion: Plasmacytoid dendritic cells evoke CTL response during S. Typhimurium infection.
Introducción. La función inmunológica de las células dendríticas plasmacitoides durante las infecciones bacterianas, como la de Salmonella spp., es poco conocida. En ese contexto, se analizó su función efectora para presentar antígenos de Salmonella Typhimurium ante linfocitos T citotóxicos. Objetivo. Analizar la respuesta de los linfocitos T citotóxicos específicos para Salmonella evocada por las células dendríticas plasmacitoides. Materiales y métodos. Se usaron células dendríticas plasmacitoides marcadas con éster de succinimidil-carboxifluoresceína, pulsadas con el epítopo de Salmonella OmpC73 Kb restringido o infectadas con S. Typhimurium como blanco en ensayos de citotoxicidad. Resultados. La lisis específica tuvo significación estadística usando células dendríticas plasmacitoides positivas pulsadas con OmpC73 en todas las relaciones de células efectoras y blanco (E:B) (p≤0,05); en cuanto a las células dendríticas plasmacitoides positivas para S. Typhimurium, solo se observó significación estadística en la relación de 1:100 (p≤0,05) usando las células efectoras OmpC73. Conclusión. Las células dendríticas plasmacitoides pueden evocar la respuesta de los linfocitos T citotóxicos durante la infección con S. Typhimurium.