Teachable moment in classrooms:

  1. cellular basis of life chapter – DNA specifies protein structure
  2. blood chapter – role of red bone marrow in hemopoesis
  3. immune system chapter – development of T and B cells and their role in the immune response
  4. immune system chapter – structure of antibodies and their binding to specific target molecules

The news item:  Recently the following news item appeared online:

Talvey Giving Patients With Heavily Pretreated Multiple Myeloma ‘a New Lease on Life’

The recent FDA approval of Talvey for heavily pretreated multiple myeloma results in an improved response to therapy and a manageable side effect profile.

The report describes that the Talvey treatment is given to multiple myeloma patients whose cancer returned despite several previous treatment with conventional drugs. The report also describes the several side effects of Talvey treatment.

So, Why Do I Care??  Every year multiple myeloma kills over 12,000 people in the USA alone. This type of cancer frequently reappears after conventional cancer treatments, and any new treatment that extends patient life after previous treatments are exhausted, is important to research.

Plain English, Please!!! First, let’s talk about what multiple myeloma is. This disorder represents a cancerous, uncontrolled cell division of plasma cells in the red bone marrow. A plasma cell is a type of white blood cell that produces antibodies during immune response. When the cancerous plasma cells quickly multiply and overtake the red bone marrow, fewer red blood cells and platelets are made, leading to fatigue, tiredness and easy bleeding.

Second, let’s talk about how Talvey works. If we want the immune system to kill cancer cells it would make sense to bring the immune system’s cells right to the cancer cells. Metaphorically speaking, picture someone trying to kill mosquitoes with a bug zapper. With one hand you hold the bug zapper, and with the other hand you grab the mosquitoes to physically bring them close to the zapper. Talvey acts in a similar fashion when it brings together the cytotoxic T cells of our immune system and the cancer cells.  Talvey is an antibody made through genetic engineering. The antibody looks like the letter Y, where the arms of the Y are sticky for binding to a target. Talvey is engineered, so one arm of the Y is sticking to myeloma cancer cells, and the other arm of the Y is sticking to the cytotoxic T cell. In that metaphor of bringing a mosquito to the bug zapper, your body is the stem of the antibody, and your hands are the sticky parts of the antibody. When the cytotoxic T cell and a cancer cell are that close to each other, the killing action of the cytotoxic T cell is very effective. Therefore, by bringing those cells together Talvey ensures the destruction of the myeloma cells.

Third, let’s talk about why cytotoxic T cells must be close to the cancer cells. Once the cytotoxic T cell binds to Talvey, the cell is activated to unleash its destructive forces. The activated T cell releases a cloud of digestive enzymes that degrade lipids in the membrane of the cancer cell. Holes in the cell membrane make the cancer cell leak their cytoplasm, and cellular metabolism, the essential chemical reactions, come to an end, and that kills the cell. That killing mechanism works best when the two cells are so close that they are almost touching each other.  If the enzymes of the T cell are released far (let’s say at a 100 cell-distance away) from the cancer cell, the enzymes will be diluted, and may react with other cells. That would cancel the killing capacity of the cytotoxic T cell.