The third line of defense in immunity involves the activation of NK cells, LAK cells, and TILs. NK cells directly kill tumor cells through cytotoxicity, while LAK cells are generated from peripheral blood lymphocytes and have enhanced antitumor activity. TILs reside within tumors and specifically target and destroy cancer cells. These cells release cytokines and activate innate immune responses, contributing to tumor cell death and immune activation against malignancies.
Meet the Unsung Heroes of Your Immune System: Key Entities in Antitumor Immunity
Immune cells are like an army protecting your body from invaders, and when it comes to fighting cancer, they’re the secret weapon you need. Let’s meet some of these incredible soldiers:
Natural Killer (NK) Cells: The Body’s Bullet-Train Surveillance System
NK cells are the quick-reaction force of your immune system. They’re constantly scanning your body, searching for suspicious cells that look like early cancer candidates. When they spot one, they’re like: “Bam! You’re out of here!” They shoot out a deadly cocktail of perforin and granzymes that’ll make any tumor cell think twice about getting in your way.
Lymphokine-Activated Killer (LAK) Cells: The Supercharged Version of NK Cells
LAK cells are the super soldiers of the immune army. They’re made by taking your peripheral blood lymphocytes (PBLs) and giving them a little extra training. Once they’re pumped up, LAK cells become even more powerful than NK cells, hitting cancer cells even harder.
Tumor-Infiltrating Lymphocytes (TILs): Sneak Attackers Behind Enemy Lines
TILs are the spies of the immune system. They infiltrate tumors and get up close and personal with cancer cells. They’re like the special ops forces, able to recognize and destroy cancer cells with precision.
These are just a few of the amazing entities that make up your antitumor immune system. Next, we’ll dive into how they team up to keep cancer at bay, with their incredible mechanisms of antitumor activity.
Mechanisms of Antitumor Activity
Direct Cytotoxicity: Unleashing the Killer Instinct
Natural Killer (NK) and Lymphokine-Activated Killer (LAK) cells are the Terminator and Sarah Connor of the immune system, infiltrating tumors and eliminating cancer cells with ruthless efficiency. These bad boys release cytotoxic grenades called perforin and granzymes that drill holes in target cells and blow them to smithereens.
Antibody-Dependent Cell-Mediated Cytotoxicity: A Targeted Take-Down
Imagine a special forces unit that targets tumor cells with laser-like precision. That’s Antibody-Dependent Cell-Mediated Cytotoxicity for you. Antibodies bind to tumor cells, lighting them up for destruction. Fas ligand (FasL), a protein released by immune cells, swoops in and delivers the fatal blow, triggering apoptosis (cell death).
Innate Immune Activation: A Chain Reaction of Destruction
Immune cells are like a well-oiled machine that triggers a ripple effect against tumors. They activate the complement system, a series of proteins that coat and weaken cancer cells, making them easy prey for immune attack. Interferons (IFNs), potent signaling molecules, are also released, sounding the alarm and mobilizing the entire immune army.
Cytokine Release: The Chemical Warfare of Antitumor Immunity
NK and LAK cells have a secret weapon: cytokines, which are like little messengers that can turn up the heat on tumor cells. Tumor necrosis factor (TNF) is one such cytokine that kicks off cell death. It’s like a hot sauce that melts away the tumor’s defenses.