Augmenting TCR signal strength and ICOS costimulation results in metabolically fit and therapeutically potent human CAR Th17 cells.

IL-17-producing antigen-specific human T cells elicit potent antitumor activity in mice. Yet, refinement of this approach is needed to position it for clinical use. While activation signal strength regulates IL-17 production by CD4+ T cells, the degree to which T cell antigen receptor (TCR) and costimulation signal strength influences Th17 immunity remains unknown. We discovered that decreasing TCR/costimulation signal strength by incremental reduction of αCD3/costimulation beads progressively altered Th17 phenotype. Moreover, Th17 cells stimulated with αCD3/inducible costimulator (ICOS) beads produced more IL-17A, IFNγ, IL-2, and IL-22 than those stimulated with αCD3/CD28 beads. Compared with Th17 cells stimulated with the standard, strong signal strength (three beads per T cell), Th17 cells propagated with 30-fold fewer αCD3/ICOS beads were less reliant on glucose and favored the central carbon pathway for bioenergetics, marked by abundant intracellular phosphoenolpyruvate (PEP). Importantly, Th17 cells stimulated with weak αCD3/ICOS beads and redirected with a chimeric antigen receptor that recognizes mesothelin were more effective at clearing human mesothelioma. Less effective CAR Th17 cells generated with high αCD3/ICOS beads were rescued by overexpressing phosphoenolpyruvate carboxykinase 1 (PCK1), a PEP regulator. Thus, Th17 therapy can be improved by using fewer activation beads during manufacturing, a finding that is cost effective and directly translatable to patients.

Arthroscopic Medial Meniscal Root Reconstruction With Gracilis Autograft Is Safe and Improves 2-Year Postoperative Patient-Reported Outcomes.

Purpose: To describe patient-reported clinical outcomes and complications of anatomic medial meniscal root reconstruction with gracilis autograft. Methods: Data on patients who underwent arthroscopic medial meniscal root reconstruction with gracilis autograft were prospectively collected between 2017 and 2021 and retrospectively reviewed. The inclusion criteria were symptomatic posterior medial meniscal LaPrade type 2 root tears with no more than Outerbridge grade 2 chondrosis of any knee compartment with a minimum follow-up period of 1 year. Patients with ligamentous instability and those with Workers' Compensation status were excluded. Patient-reported outcomes (12-item Short Form Survey [SF-12], visual analog scale [VAS], Western Ontario and McMaster Universities Arthritis Index [WOMAC], and Lysholm scores) were collected prospectively and analyzed retrospectively and were scored and recorded both preoperatively and at postoperative intervals. Data were analyzed using cubic spline regression models. The study was approved by the University of South Carolina Institutional Review Board. Results: A consecutive series of 27 patients treated by a single surgeon were evaluated. Twenty-one patients were included for data analysis (4 were excluded per criteria and 2 were lost to follow-up) with an average age of 48.1 years (range, 16-63 years). There were 18 female and 3 male patients. The average follow-up time was 25.2 months (range, 12-42 months). At the postoperative time points captured by the data examined, improvements in Lysholm, WOMAC, VAS, and SF-12 physical component summary scores were found to be statistically significant (P < .001, 95% confidence interval). Improvements in SF-12 mental component summary scores, however, did not reach the level of statistical significance (P = .262). Body mass index greater than 35 and age greater than 50 years were not found to be negative predictors of outcomes. Average patient-reported outcomes at 2 years' follow-up improved from preoperatively as follows: Lysholm score, from 50 to 82.9; WOMAC score, from 53.9 to 87.4; and VAS score, from 5.1 to 1.2. No serious complications were observed. Conclusions: Patients undergoing posterior medial meniscal root reconstruction showed statistically significant improvements in Lysholm, WOMAC, SF-12 physical component summary, and VAS scores but not SF-12 mental component summary scores at short-term follow-up. No serious complications or clinical failures occurred, and no patients required revision surgery. Level of Evidence: Level IV, case series.

Identification of human CD4+ T cell populations with distinct antitumor activity.

How naturally arising human CD4+ T helper subsets affect cancer immunotherapy is unclear. We reported that human CD4+CD26high T cells elicit potent immunity against solid tumors. As CD26high T cells are often categorized as TH17 cells for their IL-17 production and high CD26 expression, we posited these populations would have similar molecular properties. Here, we reveal that CD26high T cells are epigenetically and transcriptionally distinct from TH17 cells. Of clinical importance, CD26high and TH17 cells engineered with a chimeric antigen receptor (CAR) regressed large human tumors to a greater extent than enriched TH1 or TH2 cells. Only human CD26high T cells mediated curative responses, even when redirected with a suboptimal CAR and without aid by CD8+ CAR T cells. CD26high T cells cosecreted effector cytokines, produced cytotoxic molecules, and persisted long term. Collectively, our work underscores the promise of CD4+ T cell populations to improve durability of solid tumor therapies.

Anatomic Reinforced Medial Meniscal Root Reconstruction With Gracilis Autograft.

Meniscal root tears, left untreated, result in accelerated progression of arthritis. Numerous techniques to repair medial meniscus posterior root tears have been presented in the literature. Direct repair of the meniscus to bone without reconstructive tissue may result in a nonanatomic and biologically weak construct with a significant number of structural repair failures. Re-creation of the ligament-like structures that fix the meniscal root to bone is critical to restoring normal knee biomechanics. We present an arthroscopic reconstructive technique using gracilis autograft with suture reinforcement for medial meniscus posterior root tears.

Harnessing the Microbiome to Enhance Cancer Immunotherapy.

The microbiota plays a key role in regulating the innate and adaptive immune system. Herein, we review the immunological aspects of the microbiota in tumor immunity in mice and man, with a focus on toll-like receptor (TLR) agonists, vaccines, checkpoint modulators, chemotherapy, and adoptive T cell transfer (ACT) therapies. We propose innovative treatments that may safely harness the microbiota to enhance T cell-based therapies in cancer patients. Finally, we highlight recent developments in tumor immunotherapy, particularly novel ways to modulate the microbiome and memory T cell responses to human malignancies.

Dendritic Cells in Irradiated Mice Trigger the Functional Plasticity and Antitumor Activity of Adoptively Transferred Tc17 Cells via IL12 Signaling.

PURPOSE: The adoptive cell transfer (ACT) of CD8(+) T cells is a promising treatment for advanced malignancies. Lymphodepletion before ACT enhances IFNγ(+)CD8(+) T cell (Tc0)-mediated tumor regression. Yet, how lymphodepletion regulates the function and antitumor activity of IL17A(+)CD8(+) T cells (Tc17) is unknown. EXPERIMENTAL DESIGN: To address this question, pmel-1 CD8(+) T cells were polarized to secrete either IL17A or IFNγ. These subsets were then infused into mice with B16F10 melanoma that were lymphoreplete [no total body irradiation (TBI)], or lymphodepleted with nonmyeloablative (5 Gy) or myeloablative (9 Gy with hematopoietic stem cell transplantation) TBI. The activation of innate immune cells and function of donor T-cell subsets were monitored in recipient mice. RESULTS: Tc17 cells regress melanoma in myeloablated mice to a greater extent than in lymphoreplete or nonmyeloablated mice. TBI induced functional plasticity in Tc17 cells, causing conversion from IL17A to IFNγ producers. Additional investigation revealed that Tc17 plasticity and antitumor activity were mediated by IL12 secreted by irradiated host dendritic cells (DC). Neutralization of endogenous IL12 reduced the antitumor activity of Tc17 cells in myeloablated mice, whereas ex vivo priming with IL12 enhanced their capacity to regress melanoma in nonmyeloablated animals. This, coupled with exogenous administration of low-dose IL12, obviated the need for host preconditioning, creating curative responses in nonirradiated mice. CONCLUSIONS: Our findings indicate that TBI-induced IL12 augments Tc17 cell-mediated tumor immunity and underline the substantial implications of in vitro preparation of antitumor Tc17 cells with IL12 in the design of T-cell immunotherapies.

The inducible costimulator augments Tc17 cell responses to self and tumor tissue.

The inducible costimulator (ICOS) plays a key role in the development of Th17 cells, but its role in the development and antitumor activity of IL-17-producing CD8(+) T cells (Tc17) remains unknown. We found that ICOS costimulation was important for the functional maintenance, but not differentiation, of Tc17 cells in vitro. Blocking the ICOS pathway using an antagonist mAb or by using recipient mice genetically deficient in the ICOS ligand reduced the antitumor activity of adoptively transferred Tc17 cells. Conversely, activating Tc17 cells with an ICOS agonist in vitro enhanced their capacity to eradicate melanoma and induce autoimmune vitiligo when infused into mice. However, ICOS stimulation did not augment the antitumor activity of IL-2 expanded T cells. Additional investigation revealed that ICOS stimulation not only increased IL-2Rα, CXCR3, and IL-23R expression on Tc17 cells, but also dampened their expression of suppressive molecule CD39. Although Tc17 cells activated with an ICOS agonist cosecreted heightened IL-17A, IL-9, and IFN-γ, their therapeutic effectiveness was critically dependent on IFN-γ production. Depletion of IL-17A and IL-9 had little impact on antitumor Tc17 cells activated with an ICOS agonist. Collectively, our work reveals that the ICOS pathway potentiates the antitumor activity of adoptively transferred Tc17 cells. This work has major implications for the design of vaccine, Ab and cell-based therapies for autoimmunity, infectious disease, and cancer.