Anti-PD-1/PD-L1 Based Combination Immunotherapy to Boost Antigen-Specific CD8+ T Cell Response in Hepatocellular Carcinoma.

Peña-Asensio, J.; Calvo, H.; Torralba, M.; Miquel, J.; Sanz-de-Villalobos, E.; Larrubia, J.-R. Anti-PD-1/PD-L1 Based Combination Immunotherapy to Boost Antigen-Specific CD8+ T Cell Response in Hepatocellular Carcinoma. Cancers 2021, 13, 1922.Thirty to fifty percent of hepatocellular carcinomas (HCC) display an immune class genetic signature. In this type of tumor, HCC-specific CD8 T cells carry out a key role in HCC control. Those potential reactive HCC-specific CD8 T cells recognize either HCC immunogenic neoantigens or aberrantly expressed host’s antigens, but they become progressively exhausted or deleted. These cells express the negative immunoregulatory checkpoint programmed cell death protein 1 (PD-1) which impairs T cell receptor signaling by blocking the CD28 positive co-stimulatory signal. The pool of CD8 cells sensitive to anti-PD-1/PD-L1 treatment is the PD-1dim memory-like precursor pool that gives rise to the effector subset involved in HCC control. Due to the epigenetic imprints that are transmitted to the next generation, the effect of PD-1 blockade is transient, and repeated treatments lead to tumor resistance. During long-lasting disease, besides the TCR signaling impairment, T cells develop other failures that should be also set-up to increase T cell reactivity. Therefore, several PD-1 blockade-based combinatory therapies are currently under investigation such as adding antiangiogenics, anti-TGFβ1, blockade of other negative immune checkpoints, or increasing HCC antigen presentation. The effect of these combinations on CD8+ T cells is discussed in this review.Instituto de Salud Carlos IIIEuropean Regional Development Fund (ERDF)European UnionGilead Fellowship Programm

According to Hepatitis C Virus (HCV) Infection Stage, Interleukin-7 Plus 4-1BB Triggering Alone or Combined with PD-1 Blockade Increases TRAF1lowHCV-Specific CD8+Cell Reactivity.

Hepatitis C virus (HCV)-specific CD8+T cells suffer a progressive exhaustion during persistent infection (PI) with HCV. This process could involve the positive immune checkpoint 4-1BB/4-1BBL through the loss of its signal transducer, TRAF1. To address this issue, peripheral HCV-specific CD8+T cells (pentamer-positive [pentamer+]/CD8+T cells) from patients with PI and resolved infection (RI) after treatment were studied. The duration of HCV infection and the liver fibrosis progression rate inversely correlated with the likelihood of detection of peripheral pentamer+/CD8+cells. In PI, pentamer+/CD8+cells had impaired antigen-specific reactivity that worsened when these cells were not detectableex vivoShort/midduration PI was characterized by detectable peripheral PD-1+CD127lowTRAF1lowcells. After triggering of T cell receptors (TCR), the TRAF1 level positively correlated with the levels of CD127, Mcl-1, and CD107a expression and proliferation intensity but negatively with PD-1 expression, linking TRAF1lowto exhaustion.In vitrotreatment with interleukin-7 (IL-7) upregulated TRAF1 expression, while treatment with transforming growth factor-β1 (TGF-β1) did the opposite, suggesting that the IL-7/TGF-β1 balance, besides TCR stimulation, could be involved in TRAF1 regulation. In fact, the serum TGF-β1 concentration was higher in patients with PI than in patients with RI, and it negatively correlated with TRAF1 expression. In line with IL-7 increasing the level of TRAF1 expression, IL-7 plus 4-1BBL treatmentin vitroenhanced T cell reactivity in patients with short/midduration infection. However, in patients with long-lasting PI, anti-PD-L1, in addition to the combination of IL-7 and 4-1BBL, was necessary to reestablish T cell proliferation in individuals with slowly progressing liver fibrosis (slow fibrosers) but had no effect in rapid fibrosers. In conclusion, a peripheral hyporeactive TRAF1lowHCV-specific CD8+T cell response, restorable by IL-7 plus 4-1BBL treatment, characterizes short/midduration PI. In long-lasting disease, HCV-specific CD8+T cells are rarely detectableex vivo, but treatment with IL-7, 4-1BBL, and anti-PD-L1 recovers their reactivityin vitroin slow fibrosers.IMPORTANCEHepatitis C virus (HCV) infects 71 million people worldwide. Two-thirds develop a chronic disease that can lead to cirrhosis and hepatocellular carcinoma. Direct-acting antivirals clear the infection, but there are still patients who relapse. In these cases, additional immunotherapy could play a vital role. A successful anti-HCV immune response depends on virus-specific CD8+T cells. During chronic infection, these cells are functionally impaired, which could be due to the failure of costimulation. This study describes exhausted specific T cells, characterized by low levels of expression of the signal transducer TRAF1 of the positive costimulatory pathway 4-1BB/4-1BBL. IL-7 upregulated TRAF1 expression and improved T cell reactivity in patients with short/midduration disease, while in patients with long-lasting infection, it was also necessary to block the negative PD-1/PD-L1 checkpoint. When the results are taken together, this work supports novel ways of restoring the specific CD8+T cell response, shedding light on the importance of TRAF1 signaling. This could be a promising target for future immunotherapy

The role of CCR5/CXCR3 expressing CD8+ cells in liver damage and viral control during persistent hepatitis C virus infection

20 p.Background/Aims:CXCR3 and CCR5 play a major role in recruiting cytotoxic T cells (Tc) and secreting secondary type 1 cytokines (Tc1) in the liver. HCV could impair their expression as a survival mechanism. The role of these chemokine receptors on CD8+ cells in chronic hepatitis C is analysed. Methods:Serum, chemokines, peripheral blood and intrahepatic lymphocytes from chronic hepatitis C patients were studied. CXCR3 / CCR5 expressing CD8+ cells were quantified by flow-cytometry. Serum chemokines concentration (CXCL10/CCL3) was measured by ELISA. Basal data were correlated with liver inflammation. Longitudinal data were obtained during treatment and correlated with virologic response. Results:CCR5/CXCR3 expressing CD8+ cells were enriched in the liver and correlated with inflammation. Chronic HCV patients presented the same frequency of CCR5high/CXCR3high expressing CD8+ cells in peripheral blood as in healthy controls but higher serum concentration of CXCL10/CCL3. Treatment with PEG-interferon a-2b plus ribavirin increased CCR5high/CXCR3high expressing CD8+ cells frequency in peripheral blood and decreased CXCL10/CCL3 serum concentration. Increase in CXCR3high expressing CD8+ cells after 24 weeks of treatment was correlated with SVR. Conclusions:In chronic hepatitis C, anti-viral treatment induces an increase in CD8+ cells expressing chemokine receptors associated with Tc1 response and a reduction in their ligands. Achievement of viral control is associated with an increase in CXCR3high expressing CD8+ cells during treatmentSchering-Plough-SpainJunta de Comunidades de Castilla-La Manch

Análisis de la respuesta celular CD8 específica contra el virus B, en función del control viral y grado de inflamación hepática, en la infección presistente por virus B

Tesis de la Universidad Complutense de Madrid, Facultad de Medicina, Departamento de Medicina, leída el 21-12-2000El virus de la hepatitis B(VHB) es un virus no citopático que permanece de forma persistente en el huésped, provocando distintas situaciones clínicas. Múltiples datos indican que los linfocitos T citotóxicos VHB específicos desarrollan un papel central en el control de esta infección. Análisis matemáticos que modelan la interacción entre virus no citopáticos y la respuesta celular citotóxica, sugieren que existe una disminución en la capacidad de respuesta de los linfocitos T citotóxicos virus específicos en aquellos sujetos con infección persistente que no controlan la viremia. Por otro lado, se ha observado en modelos animales y en ciertas infecciones en humanos que el desarrollo de una respuesta celular citotóxica adecuada es capaz de controlar la infección sin generar daño tisular. Hipótesis. Basándonos en estos antecedentes, se planteó si aquellos sujetos con infección persistente por VHB sin datos de inflamación hepáticay con baja replicación viral disponían de una respuesta celular T CD8 VHB específica superior a la de los pacientes con elevada carga viral e inflamantación hepática. Métodos. La respuesta celular citotóxica desarrollada por pacientes HLA-A2+AgHBs+contra el péptido 18-27 del core de VHB se utilizó como modelo de respuesta CD8+ antígeno específica en la infección persistente por VHB. Para contrastar la hipótesis planteada se cuantificó, directamente exvivo, la frecuencia basal de linfocitos CD8 core 18-27 específicos de sangre periférica en dos grupos de sujetos con distinto grado de control viral y daño hepático. Además se evaluó la capacidad de expansión de estas células in-vitro, tras estimulación con el péptido core 18-27. En ambos análisis se utilizaron complejos tetraméricos HLA-I/péptido para el recuento de las células CD8 antígeno específicas mediante citometría de flujo. Resultados. Se observó que el control de la replicación del VHB se asociaba con la presencia de un reservorio circulante de células CD8+VHB especóficas que eran capaces de expandirse tras el reconocimiento específico del virus. Esta situación no se detectó en la mayoría de sujetos con alta viremia e inflamación hepática. Conclusiones. La existencia de una capacidad de respuesta celular citotóxica VHB específica disminuida en la infección persistente por VHB podría influir en el control de la viremia y en el desarrollo de daño hepático. El control de la replicación del VHB por las células CD8+VHB específicas podría realizarse de forma independientemen a la generación del daño tisular.Fac. de MedicinaTRUEpu

HCV&HBV immunopathogenesis

42 p

Citoquinas: papel patogénico y terapéutico de las hepatitis crónicas víricas

9 p.Cytokines make up a network of molecules involved in the regulation of immune response and organ functional homeostasis. Cytokines coordinate both physiological and pathological processes occurring in the liver during viral infection, including infection control, inflammation, regeneration, and fibrosis. Hepatitis B and hepatitis C viruses interfere with the complex cytokine network brought about by the immune system and liver cells in order to prevent an effective immune response, capable of viral control. This situation leads to intrahepatic sequestration of nonspecific inflammatory infiltrates that release proinflammatory cytokines, which in turn favor chronic inflammation and fibrosis. The therapeutical administration of cytokines such as interferon alpha may result in viral clearance during persistent infection, and revert this process.Junta de Comunidades de Castilla-La ManchaFundación de Investigación Médica Mutua Madrileñ

Gamma-Chain Receptor Cytokines & PD-1 Manipulation to Restore HCV-Specific CD8 + T Cell Response during Chronic Hepatitis C

Hepatitis C virus (HCV)-specific CD8+ T cell response is essential in natural HCV infection control, but it becomes exhausted during persistent infection. Nowadays, chronic HCV infection can be resolved by direct acting anti-viral treatment, but there are still some non-responders that could benefit from CD8+ T cell response restoration. To become fully reactive, T cell needs the complete release of T cell receptor (TCR) signalling but, during exhaustion this is blocked by the PD-1 effect on CD28 triggering. The T cell pool sensitive to PD-1 modulation is the progenitor subset but not the terminally differentiated effector population. Nevertheless, the blockade of PD-1/PD-L1 checkpoint cannot be always enough to restore this pool. This is due to the HCV ability to impair other co-stimulatory mechanisms and metabolic pathways and to induce a pro-apoptotic state besides the TCR signalling impairment. In this sense, gamma-chain receptor cytokines involved in memory generation and maintenance, such as low-level IL-2, IL-7, IL-15, and IL-21, might carry out a positive effect on metabolic reprogramming, apoptosis blockade and restoration of co-stimulatory signalling. This review sheds light on the role of combinatory immunotherapeutic strategies to restore a reactive anti-HCV T cell response based on the mixture of PD-1 blocking plus IL-2/IL-7/IL-15/IL-21 treatment.MINECOInstituto de Salud Carlos IIIEuropean CommissionGilead Fellowship ProgrammeEuropean Regional Development Fund (ERDF