Cytotoxic human lymphocytes: from in vitro testing (1970s) to immunotherapy (1990s)

Area of Science:

• Immunology
• Cancer Research
• Cellular Therapy

Background:

• The National Cancer Institute (NCI) aimed to develop a tumor-specific human lymphocyte-mediated cytotoxicity assay in the early 1970s.
• Technological limitations, including the absence of lymphocyte growth factors and monoclonal antibodies, hindered the establishment of specific assays.
• Early research recognized tumor-specific lymphocytes but noted their frequent overshadowing by indiscriminately cytotoxic populations.

Observation:

• Indiscriminately cytotoxic lymphocytes were found in both cancer patients and healthy individuals, challenging the prevailing scientific doctrine.
• The senior author's own lymphocytes demonstrated indiscriminate cytotoxicity in 1971, initially interpreted as immune surveillance.
• Despite the NCI contract's premature termination, crucial observations regarding cytotoxic lymphocytes were made.

Findings:

• The study identified and characterized both tumor-specific and non-specific cytotoxic lymphocyte populations.
• Early observations foreshadowed the well-established functions of cytotoxic lymphocytes.
• The groundwork was laid for adoptive immunotherapy using autologous lymphocyte populations.

Implications:

• These foundational studies highlighted the potential of lymphocyte-based therapies for cancer treatment.
• The research provided insights into the complex interactions of the immune system in cancer.
• The work contributed to the development of laboratory techniques for preparing lymphocytes for therapeutic use.