X-linked retinoschisis is a retinovitreal disorder primarily affecting males, starting in childhood. Over time, patients experience deterioration of vision due to the lack of retinoschisin-1 function. In clinical trials performing intravitreal gene delivery in those affected by this disorder, ocular inflammation was observed, which may have masked efficacy. A subsequent study focusing on analyzing the populations of peripheral blood mononuclear cells and cytokines in adults with this disease reported aberrant dendritic cell numbers and cytokine levels in peripheral blood, indicating that adults with this disease may have an altered baseline immunity. Whether the aberrant peripheral immunity in affected adults was a consequence of advanced eye pathology remained unclear. This study focuses on analyzing the populations of blood lymphocyte subsets in children aged 0 to 7 years with X-linked retinoschisis and age-matched controls using flow cytometry.
The fractions of lymphocyte subsets that were CD16a+/CD56+, namely natural killer cells, were significantly lower in blood samples from children with X-linked retinoschisis. In children with X-linked retinoschisis, the fractions of CD3+/CD4 + T cells were higher, and the fractions of CD3 + CD8 + T cells were lower, despite having the same amounts of total CD3 + T cells within their lymphocyte populations. This resulted in a significantly greater CD4/CD8 ratio in children with X-linked retinoschisis compared to age-matched controls.
Alterations were found in blood lymphocyte compositions of children with X-linked retinoschisis within both innate and adaptive immune axes. Some alterations including an elevation of CD4/CD8 ratio in X-linked retinoschisis mirror those previously found in adult patients with this disease. The fact that these abnormalities were present early in this disease indicates that retinoschisin-1 may play a role in regulating immunity in addition to retinal structure. The findings may have implications for future treatments such as ocular gene delivery.
© 2025. The Author(s).

Abstract Background. X-linked retinoschisis is a retinovitreal disorder primarily affecting males, starting in childhood. Over time, patients experience deterioration of vision due to the lack of retinoschisin-1 function. In clinical trials performing ocular gene delivery in those affected by this disorder, ocular inflammation was observed, which may have masked efficacy. A subsequent study focusing on analyzing the populations of peripheral blood mononuclear cells and cytokines in adults with this disease reported aberrant dendritic cell numbers and cytokine levels in peripheral blood. Adults with this disease may have an altered baseline immunity. However, children with X-linked retinoschisis were not included in that study, and whether the aberrant peripheral immunity in affected adults was a consequence of advanced eye pathology remained unclear. This study focuses on analyzing the populations of blood lymphocyte subsets in children aged 0 to 7 with X-linked retinoschisis and age-matched controls using flow cytometry. Results. The fractions of lymphocyte subsets that were CD16a + were significantly lower in children with X-linked retinoschisis. The fractions of lymphocyte subsets that were CD16a+/CD56+, namely natural killer cells, were also significantly lower. In children with X-linked retinoschisis, the fractions of CD3+/CD4 + T cells were higher, and the fractions of CD3 + CD8 + T cells were lower, despite having the same amounts of total CD3 + T cells within their lymphocyte populations. This resulted in a significantly greater CD4/CD8 ratio in children with X-linked retinoschisis compared to age-matched controls. Conclusions. Alterations were found in blood lymphocyte compositions of children with X-linked retinoschisis within both innate and adaptive immune axes. Some alterations including an elevation of CD4/CD8 ratio in X-linked retinoschisis mirror those previously found in adult patients with this disease. The fact that these abnormalities were present early in this disease indicates that retinoschisin-1 may play a role in regulating immunity in addition to retinal adhesion. The findings may have implications for future treatments such as ocular gene delivery.

Phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling is involved in the growth of normal and cancer cells and is crucial for T cell activation. Previously, we have shown that AKT Inhibitor VIII, a selective AKT-1/2 inhibitor, during chimeric antigen receptor (CAR) T cell manufacturing, improves CAR T cell function in preclinical models. Although AKT Inhibitor VIII could enhance CAR T cell function, AKT Inhibitor VIII is not a clinical-grade compound. However, pan-AKT inhibitors have been applied against cancers with PIK3CA/AKT/PTEN alterations in clinical trials. We evaluated ex vivo and in vivo strategies of enhancing CAR T cell therapeutic effect using the pan-AKT inhibitor capivasertib. We found that ex vivo 0.25 μM capivasertib treatment during the period of T cell stimulation during manufacture enhanced the antitumor activity of CAR T cells in B cell lymphoma mouse models. Mechanistically, capivasertib changed gene and protein expression patterns related to the functions of memory and effector CAR T cells. Furthermore, in vivo combination therapy of capivasertib and CD19-specific CAR T cells led to improved early response to and persistence of functional CAR T cells in mice bearing PTEN-deficient lymphoma cells compared to CAR T cells alone. Capivasertib exerts a similar function to AKT Inhibitor VIII in modulating CAR T cells, and combining CAR T cell therapy with capivasertib both ex vivo and in vivo offers the potential to improve patient outcomes. Since PTEN deficiency is common in cancer and is the main mechanism for capivasertib function, combination therapy may provide an alternative solution for the challenges of CAR T cell therapy.
© 2025 The Author(s).

The efficacy of chimeric antigen receptor T cells (CART) in solid tumors is limited by immune inhibition. In our study, we observed that effector cytokines mediated the upregulation of the PD-L1 immune checkpoint in primary glioblastoma. To offset the PD-L1 inhibitory signal, we engineered PD-1 checkpoint reversal receptors (CPR) with a CD28 or 41BB costimulatory endodomain and coexpressed them with a first-generation or a CD28-containing second-generation HER2-specific CAR (CPR/CART) using bicistronic vectors. We found that bipartite T-cell activation, by CAR-generated signal 1 and CPR costimulation (signal 2), fine-tuned proinflammatory cytokine release and sustained antitumor activity. Whereas both CPR28 and CPR41BB effectively counteracted the PD-1 signal in vitro, CPR41BB, when coexpressed with a first-generation CAR (CARζ/CPR41BB), promoted central memory differentiation following repeat antigenic stimulation. CARζ/CPR41BB T cells formed a robust immune synapse with tumor targets, similar to a 41BB-containing second-generation CART, maintained the favorable metabolic parameters associated with 41BB costimulation, and demonstrated superior antitumor function after adoptive transfer in xenograft models of gioblastoma and metastatic osteosarcoma. Thus, a CPR molecule with 41BB costimulation that curtails PD-1 inhibition and complements CAR signaling to optimize T-cell activation could enhance CART efficacy against solid tumors.
Enhancing CART function and persistence while balancing immune effector-mediated inflammation is crucial. Using our clinically relevant HER2-CAR platform, we demonstrate that tumor-intrinsic signals like the PD-1/PD-L1 immune checkpoint can be leveraged in CART design to modulate immune synapse and metabolic parameters, improving antitumor function without increasing cytokine production.
©2025 The Authors; Published by the American Association for Cancer Research.

Melanoma is a highly aggressive form of skin cancer. The existence of cancer stem cells (CSCs) and tumor immune evasion are two major causes of melanoma progression, but no effective treatment has been found at present. Astragalus polysaccharide (APS) is a principal active component derived from Astragalus membranaceus, showing anti-tumor effects in various tumors including melanoma. However, the underlying mechanism is still unclear.
The regulation of APS on self-renewal ability and CSC markers expression in melanoma stem cells (MSCs) was measured by tumor sphere formation and tumorigenicity assays, RT-qPCR, and western blot. Flow cytometry was conducted to evaluate the activation of immune system by APS in melanoma mice. Further, the mechanism was explored based on PD-L1 overexpression and knock-down B16 cells.
APS attenuated the tumor sphere formation of MSCs in vitro as well as the tumorigenicity in vivo. It also decreased the expression of CD133, BMI1 and CD47. Based on the PD-L1 overexpression and knock-down B16 cells, it was confirmed that APS inhibited the induction of MSCs by down-regulating PD-L1 expression. Meanwhile, APS increased the infiltration of CD4+ and CD8+T cells in tumor tissues because of its inhibitory effect on PD-L1.
APS inhibited MSC induction and overcame tumor immune evasion through reducing PD-L1 expression. This study provided compelling evidence that APS could be a prospective therapeutic agent for treating melanoma.
© 2024. The Author(s).