PNAS: New cancer immunotherapy is available! The scavenger's subject MARCO, which targets tumor-related macrophages, activates tumor cell lethality in NK cells

Nov 25, 2020 /---/ -- Cancer immunotherapy has come a long way, and many patients now have access to effective treatments that were not available 10 years ago.
, however, certain types of cancer do not respond to existing immunotherapy.
, researchers from Sweden's Karolinska Institute have reported a new immunotherapy in a new study, giving hope to more cancer treatment options in the future.
results were published online November 23, 2020 in the journal PNAS under the title "Targeting a scavenger receptor on tumor-associated macrophages active cell cell by natural killer cells".
tumor-related macrophages play a major role in tumor occurrence.
photo from Journal of Biomedical Science, 2019, doi:10.1186/s12929-019-0568-z.
cancer cells reprogram immune cells to facilitate tumor growth.
years of research, people have been able to use the immune system to fight cancer, that is, different antibodies can trigger T cells in the immune system to attack cancer cells.
macrophages are different types of immune cells that play a vital role in the immune system, recruiting T cells to areas affected by alien organisms and regulating their function.
unfortunately, some tumors develop ways to shut down the immune system, including allowing macrophages in tumors--- tumor-related macrophages (TUMOR-associated macrophages, TAM) to block T-cells---
the scavenger's subject MARCO is expressed in a specific TAM cell subsyshell.
In order to prevent TAM-mediated immunosuppression, the researchers injected scavenger-specific antibodies to the scavenger's subject MARCO, which reduces tumor vascularization and activates TAM, which expresses MARCO, which is then activated by the ligand TRAIL.
activated NK cells reverse the effect of TAM cells blocking NK cell activation in melanoma and work with immunotherapy that activates T cells, such as PD-1 or PD-L1 antibodies, to enhance tumor damage.
, the study revealed that targeting immunosuppressive tumor micro-environments with monoclonal antibodies can enhance NK cell activity and NK cell-mediated lethality.
can complement existing immunotherapy that activates T-cells, providing a promising way to combine cancer immunotherapy. "In our study, we developed a new type of immunotherapy: specific antibodies activate macrophages, allowing them to support the immune system and kill cancer cells," said Mikael Karlsson, co-author of the
paper and professor in the Department of Microbiology, Oncology and Cell Biology at the Karolinska Institute. The
study also showed that NK cells, another important cell of the immune system, are primarily activated by this new immunotherapy and work with T cells to kill tumors, where as in existing immunotherapy, only T cells are activated.
NK cells are also proven to be very effective in fighting cancer when activated by macrophages, " said Karlsson, a professor at the University of Nk.
" study, conducted in collaboration with Rockefeller University, was originally a modeling study.
, the researchers applied their findings to human skin tumors to test the convertability of their results.
, Karlsson explained , " we can also observe that these specific antibodies trigger human macrophages , which in turn activate NK cells to kill cancer cells . "
, these findings suggest that this new type of immunotherapy activates different parts of the immune system compared to previous immunotherapy and is expected to be used in conjunction with existing therapies.
Karlsson concluded, "The teamwork between NK cells and T cells has improved their efficacy, which will help to make more types of cancers treated in the future."
" (Bioon.com) Reference: 1.Silke Eisinger el al. Targeting scavenger receptor MARCO on tumor-associated macrophages activates TRAIL-dependent tumor cell killing by natural killer cells. PNAS, 2020, doi:10.1073/pnas.2015343117.2.New type of immunotherapy may pave the way for better cancer treatments。