Decreased PD-1 Expression on CD8 Lymphocyte Subsets and Increase in CD8 Tscm Cells in Children with HIV Receiving Raltegravir

CAR-T Cells with Phytohemagglutinin (PHA) Provide Anti-Cancer Capacity with Better Proliferation, Rejuvenated Effector Memory, and Reduced Exhausted T Cell Frequencies

The development of genetic modification techniques has led to a new era in cancer treatments that have been limited to conventional treatments such as chemotherapy. intensive efforts are being performed to develop cancer-targeted therapies to avoid the elimination of non-cancerous cells. One of the most promising approaches is genetically modified CAR-T cell therapy. The high central memory T cell (Tcm) and stem cell-like memory T cell (Tscm) ratios in the CAR-T cell population increase the effectiveness of immunotherapy. Therefore, it is important to increase the populations of CAR-expressing Tcm and Tscm cells to ensure that CAR-T cells remain long-term and have cytotoxic (anti-tumor) efficacy. In this study, we aimed to improve CAR-T cell therapy's time-dependent efficacy and stability, increasing the survival time and reducing the probability of cancer cell growth. To increase the sub-population of Tcm and Tscm in CAR-T cells, we investigated the production of a long-term stable and efficient cytotoxic CAR-T cell by modifications in the cell activation-dependent production using Phytohemagglutinin (PHA). PHA, a lectin that binds to the membranes of T cells and increases metabolic activity and cell division, is studied to increase the Tcm and Tscm population. Although it is known that PHA significantly increases Tcm cells, B-lymphocyte antigen CD19-specific CAR-T cell expansion, its anti-cancer and memory capacity has not yet been tested compared with aCD3/aCD28-amplified CAR-T cells. Two different types of CARs (aCD19 scFv CD8-(CD28 or 4-1BB)-CD3z-EGFRt)-expressing T cells were generated and their immunogenic phenotype, exhausted phenotype, Tcm-Tscm populations, and cytotoxic activities were determined in this study. The proportion of T cell memory phenotype in the CAR-T cell populations generated by PHA was observed to be higher than that of aCD3/aCD28-amplified CAR-T cells with similar and higher proliferation capacity. Here, we show that PHA provides long-term and efficient CAR-T cell production, suggesting a potential alternative to aCD3/aCD28-amplified CAR-T cells.

Immunotherapeutic Potential of T Memory Stem Cells

Memory T cells include T memory stem cells (T_SCM) and central memory T cells (T_CM). Compared with effector memory T cells (T_EM) and effector T cells (T_EFF), they have better durability and anti-tumor immunity. Recent studies have shown that although T_SCM has excellent self-renewal ability and versatility, if it is often exposed to antigens and inflammatory signals, T_SCM will behave as a variety of inhibitory receptors such as PD-1, TIM-3 and LAG-3 expression, and metabolic changes from oxidative phosphorylation to glycolysis. These changes can lead to the exhaustion of T cells. Cumulative evidence in animal experiments shows that it is the least differentiated cell in the memory T lymphocyte system and is a central participant in many physiological and pathological processes in humans. It has a good clinical application prospect, so it is more and more important to study the factors affecting the formation of T_SCM. This article summarizes and prospects the phenotypic and functional characteristics of T_SCM, the regulation mechanism of formation, and its application in treatment of clinical diseases.

Disease Progression in Children with Perinatal HIV Correlates with Increased PD-1+ CD8 T Cells that Coexpress Multiple Immune Checkpoints

BACKGROUND

PD-1 marks exhausted T cells, with weak effector functions. Adults living with HIV have increased levels of PD-1+ CD8 T cells that correlate with HIV disease progression, yet little is known about the role of PD-1+ CD8 T cells in children with perinatal HIV.

METHODS

We enrolled 76 Kenyan children with perinatal HIV and 43 children who were HIV unexposed and quantified PD-1 levels on CD8 T cells, their coexpression with immune checkpoints (IC) 2B4, CD160 and TIM3, correlates with immune activation and HIV disease progression and HIV-specific and non-specific proliferative responses.

RESULTS

PD-1+ CD8 T cell frequencies are elevated in children with perinatal HIV and associated with disease progression. The majority of PD-1+ CD8 T cells coexpress additional ICs. ART initiation lowers total PD-1 levels and coexpression of multiple ICs. The frequency of PD-1 + 2B4+CD160+TIM3- in PD-1+ CD8 T cells, predicts weaker HIV-specific proliferative responses, suggesting this subset is functionally exhausted.

CONCLUSION

Children with perinatal HIV have high PD-1+ CD8 T cells that are a heterogeneous population differentially coexpressing multiple ICs. Understanding the complex interplay of ICs is essential to guide the development of PD-1 directed immunotherapies for pediatric HIV remission and cure.

High soluble CD163 levels correlate with disease progression and inflammation in Kenyan children with perinatal HIV-infection

OBJECTIVES

CD163 is a hemoglobin scavenger receptor on monocytes and macrophages, cleaved to soluble CD163 (sCD163) in the plasma following activation. In HIV+ adults, sCD163 is linked to non-AIDS morbidity and predicts mortality, but there is limited data in children. We investigated sCD163 levels in HIV+ children and their correlations with disease progression, immune activation and gut mucosal damage.

DESIGN AND METHODS

We quantified sCD163 levels in Kenyan children aged 0-20 years with perinatal HIV infection, including 74 antiretroviral treatment (ART)-naïve (ART-) and 64 virally suppressed on ART (ART+), and 79 HIV unexposed-uninfected controls (HIV-). The cohort was divided into age groups 0-5 (younger) and 5-20 (older) years. Correlations between sCD163 and HIV viral load, %CD8, CD4 : CD8 ratio, markers of T-cell activation and proliferation, and gut mucosal damage were also assessed.

RESULTS

ART- children have higher sCD163 levels compared with HIV- and ART+ children (P ≤ 0.01); ART+ have equivalent sCD163 levels to HIV- children. In a prospective analysis, sCD163 levels decreased in older ART- children after 12 months of treatment (P < 0.0001). Regardless of age, sCD163 levels correlate with clinical disease progression measured by %CD4 T cells, CD4 : CD8 T-cell ratios and HIV viral load. sCD163 levels directly correlate with T-cell activation markers CD38, human leukocyte antigen-DR isotype, and Ki67 (P ≤ 0.01).

CONCLUSION

High plasma sCD163 levels in HIV+ children correlate with advancing disease and T-cell activation. ART initiation normalizes sCD163 levels and may alleviate HIV-related morbidities and improve long-term pediatric outcomes.

Model-Based Methods to Translate Adolescent Medicine Trials Network for HIV/AIDS Interventions Findings Into Policy Recommendations: Rationale and Protocol for a Modeling Core (ATN 161)

Background

The United States Centers for Disease Control and Prevention estimates that approximately 60,000 US youth are living with HIV. US youth living with HIV (YLWH) have poorer outcomes compared with adults, including lower rates of diagnosis, engagement, retention, and virologic suppression. With Adolescent Medicine Trials Network for HIV/AIDS Interventions (ATN) support, new trials of youth-centered interventions to improve retention in care and medication adherence among YLWH are underway.

Objective

This study aimed to use a computer simulation model, the Cost-Effectiveness of Preventing AIDS Complications (CEPAC)-Adolescent Model, to evaluate selected ongoing and forthcoming ATN interventions to improve viral load suppression among YLWH and to define the benchmarks for uptake, effectiveness, durability of effect, and cost that will make these interventions clinically beneficial and cost-effective.

Methods

This protocol, ATN 161, establishes the ATN Modeling Core. The Modeling Core leverages extensive data—already collected by successfully completed National Institutes of Health–supported studies—to develop novel approaches for modeling critical components of HIV disease and care in YLWH. As new data emerge from ongoing ATN trials during the award period about the effectiveness of novel interventions, the CEPAC-Adolescent simulation model will serve as a flexible tool to project their long-term clinical impact and cost-effectiveness. The Modeling Core will derive model input parameters and create a model structure that reflects key aspects of HIV acquisition, progression, and treatment in YLWH. The ATN Modeling Core Steering Committee, with guidance from ATN leadership and scientific experts, will select and prioritize specific model-based analyses as well as provide feedback on derivation of model input parameters and model assumptions. Project-specific teams will help frame research questions for model-based analyses as well as provide feedback regarding project-specific inputs, results, sensitivity analyses, and policy conclusions.

Results

This project was funded as of September 2017.

Conclusions

The ATN Modeling Core will provide critical information to guide the scale-up of ATN interventions and the translation of ATN data into policy recommendations for YLWH in the United States.