Millions of cancer cases are detected worldwide annually. Cancer being one of the most common diseases or, rather a healthcare challenge in today’s time and age. In recent years, immunotherapy has emerged as a game changer for treating cancer, as it helps the body’s immune system to combat the tumor cells.
The traditional cancer treatments such as chemotherapy and radiation have been in the system from ages but they have severe side effects and are not effective in a few cases as well.
These methods have also not proven effective, especially in the later stages of the diseases; thus, they are still questionable, whereas leveraging your body’s immune system to combat the disease has proven much more effective in comparison. Center to this strategy is T cell activation, a type of white blood cell that plays a vital role in the immune response.
Know About the T Cells
T cells are essential for identifying and destroying the infected or the cancerous cells in the body. The T cells or T lymphocytes are immune cells that originate from the stem cells in the bone marrow and mature in the thymus.
These T cells can be broadly classified into two categories: CD8+ cytotoxic T cells and CD4+ helper T cells. While CD8+ T cells directly kill the infected or the malignant cells, CD4+ T cells assist other cells in the immune system in responding, including the B & T cells.
T cells Activation
The activation of T-cells is a complex process that begins with identifying the T cell’s antigens presented by major histocompatibility complex (MHC) molecules on the surface of antigen-presenting cells (APCs) such as dendritic cells.
This recognition is mediated by the T cell receptor (TCR). Once the TCR binds to the antigens- MHC Complex, a cascade of signaling events is triggered, leading to the proliferation and differentiation of T cells into effector cells, which are capable of targeting and eliminating the tumor cells.
Types of T-cells
- Helper T Cells (CD4+ T cells): These cells do not directly kill the infected cellsbut instead help coordinate the immune response by signaling the other cells, like B cells to produce antibodies and cytotoxic T cells to kill infected cells.
- Regulatory T Cells (Tregs): These cells help modulate the immune response, preventing autoimmune diseases by suppressing excessive immune reactions.
- Cytotoxic T Cells (CD8+ T Cells): These cells directly kill the infected cells, cancer cells, and sometimes even the damaged or dysfunctional cells.
- Memory T Cell: These cells remain in the bosy post treatment and infection has been cleared, it helps in providing faster and more impactful response if the same pathogen is encountered again in the system.
Mechanisms of T-cell Mediated Anti-Tumor Response
- Direct Killing of Tumor Cells – Activated CD8+ T cells can directly kill tumor cells. They recognize specific markers (antigens) on the surface of tumor cells presented by MHC class I molecules. Once they recognize these markers, they release substances called perforin and granzymes. Perforin creates holes in the tumor cells membrane, and granzymes enter the tumor cells through these holes to trigger apoptosis or programmed cell death.
- Enhancement of Antigen Presentation – CD4+ helper T cells assist antigens-presenting cells (APC) in showing the tumor antigens more effectively, which strengthens the overall immune response. They also support the activation and multiplication of CD8+ T cells, leading to a stronger attack on the tumor.
- Memory T-cells – Some activated T-cells turn into memory T cells, which stay in the body for a long time and provide ongoing immunity against the tumor. If the tumor reoccuers the memory T-cells can quickly recognise them and launch a fast and effective immune response.
- Cytokine Production – Activated T-cells produce signaling proteins called cytokines, such as interferon-gamma and tumor necrosis factor-alpha, these cytokines helps in:
- Stopping the tumor growth
- Induce tumor cell death
- Boost the activities of other immune cells like natural killer cells and macrophage
Conclusion
The activation of T cells plays a very vital role in the anti-tumor response; it offers an on-point and direct approach to cancer treatment. The evolution and advancements in immunotherapy that particularly focus on T-cell function and activation have revolutionized the field to provide new care and hope to patients.
As many researchers still continue to prove and evolve the complexities associated with T-cell biology and tumor immunology, the development of the T-cell will become more combust and personalized to promise a great future for cancer cure and treatment.
