IL-7 and CCR2b Co-Expression-Mediated Enhanced CAR-T Survival and Infiltration in Solid Tumors

Abstract

Chimeric antigen receptor T (CAR-T) cells are not effective in solid tumor treatment due to reduced invasion and expansion, and short survival time. This study aimed to explore whether interleukin (IL)-7 and CCR2b expression could improve GD2-CAR-T cell survival and infiltration in neuroblastoma and melanoma treatment. IL-7 and CCR2b were inserted into the classical second-generation CAR structure to construct 7×2b CAR. The 7×2b CAR-T cell phenotypes were evaluated by flow cytometry and the chemokine levels by ELISA. The 7×2b CAR-T cell migration and anti-tumor abilities were detected by Transwell assay and animal experiments in vivo. We report that compared with that of CAR-T cells, 7×2b CAR-T cell IL-7 secretion and CCR2b expression did not affect the T cell surface expression of CAR or CAR-T specificity and efficacy against tumor cells. The 7×2b CAR-T cells could induce IFN-γ secretion in GD2-positive tumor cells, killing them as well as conventional CAR-T cells. Moreover, IL-7 and CCR2b co-expression enhanced the 7×2b CAR-T cell survival and migration. Similar to conventional CAR-T, 7×2b CAR-T cells could also inhibit tumor growth and increase IFN-γ, Gzms-B, and IL-2 expression. Finally, unlike in mice injected with CAR-T cells, CD3 expression was the most abundant in the spleen and tumor tissues in mice injected with 7×2b CAR-T cells. Our study demonstrates that IL-7 and CCR2b co-expression in GD2-CAR-T cells exhibit stronger anti-tumor activity than classical second-generation CAR-T cells, shedding light on the potential novel GD2-positive neuroblastoma and melanoma treatment approach.

Case Report: Chimeric Antigen Receptor T Cells Induced Late Severe Cytokine Release Syndrome

“…In case two, on day 163 the laboratory examination showed elevated CRP ( Table 2 ), suggesting that inflammatory cascade may be the reason for CART re-expansion. Elevation of cytokines, such as IL-15, IL-21, IL-6, and IL-7, has been reported to promote the expansion of CART ( 35 – 37 ). We speculated that due to different factors cytokines partially increased, resulting in the expansion of CART.…”

Immunosuppression in tumor immune microenvironment and its optimization from CAR-T cell therapy

“…The Msln-CCR2b-CAR and/or Msln-CCR4-CAR T cells possessed fortified migration and infiltration, specifically exerted cytotoxicity, and expressed high levels of pro-inflammatory cytokines. Compared with traditional CAR-T cells, IL-7 and CCR2b co-expressing CAR-T cells boosted self-survival and migration, enhanced IFN-γ, Gzms-B, and IL-2 expression, and obstructed tumor growth 152 . These strategies all pave the way for the clinical application of CAR-T cells.…”

Gene-modified T cell therapy for cancer: Current challenges and potential solutions

“…CAR-T cells targeting mesothelin expressing CCR2b can enhance migration to tumor sites and their anti-tumor capacity [79] . Moreover, GD2-specific CAR-T cells expressing IL-7 and CCR2b have a stronger capacity for tumor infiltration and antitumor effects in the neuroblastoma model [80] . Studies have shown that the ligand of CXCR2 is highly expressed in hepatocellular carcinoma tissues and cell lines, while infiltrating T cells express lower levels of CXCR2, and CAR-T cells overexpressing CXCR2 produce enhanced anti-tumor activity by improving the infiltration of CAR-T cells [81] .…”