Lymphocytes versus lymphocytes
According to a study by Mount Sinai Medical Center in New York, a new approach to cancer immunotherapy, in which one type of immune cell attacks another, rather than directly killing cancer cells, causes a sustained antitumor immune response that leads to regression of ovarian, lung and pancreatic tumors.
CAR-T cells are the patient's own lymphocytes modified for direct recognition of cancer cells. Currently, they are used for the treatment of oncological diseases of the blood, but they are not very effective for solid tumors.
The fact is that most "solid" tumors are abundantly infiltrated by another type of immune cells – macrophages. They block the penetration of T cells into the tumor tissue, thus reducing the effectiveness of CAR T therapy. To cope with the negative influence of macrophages, the researchers targeted them with CAR-T cells.
Treatment of mice with ovarian, lung and pancreatic cancers with macrophage-targeted CAR-T cells reduced the size of tumors and increased the survival rate of animals. The destruction of tumor macrophages allowed their own T-lymphocytes to gain access to cancer cells and kill them.
Although the original goal of the study was simply to use CAR-T cells to destroy immunosuppressive macrophages, but the authors found that the treatment also increases antitumor immunity by releasing the cytokine interferon-gamma from CAR-T cells.
Molecular studies of human tumor samples have shown that subsets of tumor macrophages are similar in different types of cancer and are very different from macrophages in healthy tissues. Currently, the group is working on a CAR specific for tumor macrophages and creating humanized versions of genetic instructions so that they can be injected into cancer patients' own T-cells.
Article by A.Sánchez-Paulete et al. Targeting Macrophages with CAR T Cells Delays Solid Tumor Progression and Enhances Antitumor Immunity is published in the journal Cancer Immunology Research.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru .