Page 97 - Control Theory in Biomedical Engineering

84 Control theory in biomedical engineering

T lymphocytes and memory B cells will be created and be available to
remember a particular species of pathogen or other antigenic substance,
so that the response will be effective and rapid on subsequent exposure
(Byrne et al., 2006).
Although there are great research efforts dedicated to revealing the rela-
tion between tumor cells and the IS, cancer is still considered as one of the
most challenging diseases to treat. The desired outcome from cancer treat-
ment should be destruction of all cancer cells in the body while maintaining
the minimum level of healthy cells. Chemotherapy is one of the most highly
adopted cancer treatment modalities; however, it was proved not to be the
most convenient solution for tumor regression (de Pillis and Radunskaya,
2003; Swan, 1985). Progress is being made in attempting to eliminate tumor
cells in the host by using an experimental form of immunotherapy
(American Association for Cancer Research, 2016; Liu et al., 2002).
Immunotherapy (which is sometimes referred to as biological therapy) is
quickly becoming one of the most important components of cancer treat-
ments, especially in multipronged approaches (Neves and Fai Kwok, 2015).
The goal of immunotherapy is to reinforce the body’s own natural ability to
combat cancer by enhancing the effectiveness of the IS to act against cancer
a
cells, which involves the use of cytokines with adoptive cellular immuno-
therapy (ACI), derived from the body or laboratory-produced versions of
such substances, to improve or restore IS function ( Joshi et al., 2009; Kirsch-
ner and Panetta, 1998). Although it is not entirely clear how immunother-
apy treats cancer, it may work by stopping or slowing the growth of cancer
cells, stopping cancer from spreading to other parts of the body, or helping
the IS increase its effectiveness at eliminating cancer cells (Kuznetsov et al.,
1994). There are three known categories of immunotherapy: immune
b
response modifiers (cytokines), monoclonal antibodies and vaccines. c
The most commons cytokines are IL-2 and interferon-alpha (INF-α)
(Lackie, 2010). IL-2 does not kill tumor cells directly like classical chemo-
therapy. Instead, IL-2 activates and stimulates the growth of immune cells,

a
Cytokines: Protein hormones that mediate both natural and specific immunity, called inter-
ferons and interleukins. They increase the production of immune cells, can be made in the
laboratory and given to patients as part of treatment for cancer.
b
Monoclonal antibodies: a type of immunotherapy, are made in the laboratory. Monoclonal
antibodies may be used alone, or they may have an attached drug or radioactive material.
c
Cancer vaccines, another type of immunotherapy, stimulate the body’s IS to destroy cancer
cells.