Tumor-infiltrating lymphocytes

Tumor-infiltrating lymphocytes (TIL) are white blood cells that have left the bloodstream and migrated towards a tumor.

Detection of gene expression specific for different kind of immune cell populations can then be used to determine the degree of lymphocyte infiltration as has been shown in breast cancer.

[17] Rosenberg and colleagues have conducted clinical trials for more than two decades using TIL adoptive cell therapy for melanoma.

[19][20] Several centers currently have established TIL therapy protocols for the treatment of melanoma, including the MD Anderson Cancer Center in Houston, Texas,[17] Ella Institute in Sheba Hospital, Israel,[19] and Copenhagen University Hospital in Herlev, Denmark.

Selected TIL lines that presented best tumor reactivity are then further expanded in a "rapid expansion protocol" (REP), which uses anti-CD3 activation for a typical period of two weeks.

The process can also involve a preliminary chemotherapy regimen to deplete endogenous lymphocytes in order to provide the adoptively transferred TILs with enough access to surround the tumor sites.

[23] The combination of TILs with a high dose of IL-2 presents multiple clinical trials demonstrating rates near 50% or more patients effectively responding.

[17] In a randomized, phase III trial conducted between 2014 and 2022 in Denmark and The Netherlands, researchers found that treatment with TILs was superior to ipilimumab in metastatic melanoma.

[18] Current studies involve investigating the roles of chemotherapy drugs in combination with TIL therapy to assess improved response rates and synergistic efficacy.

During the elimination phase immune effector cells such as CTL ’s and NK cells with the help of dendritic and CD4+ T-cells are able to recognize and eliminate tumor cells.
Very high magnification micrograph of tumor infiltrating lymphocytes , abbreviated TILs , in a case of colorectal carcinoma . TILs may also be spelled tumour infiltrating lymphocytes . H&E stain .
Cancer specific T-cells can be obtained by fragmentation and isolation of tumor infiltrating lymphocytes, or by genetically engineering cells from peripheral blood. The cells are activated and grown prior to transfusion into the recipient (tumor bearer).