Biomedical Engineering Reference
In-Depth Information
22
Immunomodulating Agents
Ulla G. Sidelmann
CONTENTS
22.1 Introduction ......................................................................................................................... 359
22.2 Brief Introduction to the Immune System .......................................................................... 360
22.2.1 Cells of the Immune System .................................................................................. 360
22.2.1.1 B Cells .................................................................................................... 361
22.2.1.2 T Cells .................................................................................................... 361
22.2.2 Antibodies..............................................................................................................363
22.2.3 Natural Killer Cells................................................................................................ 363
22.3 Diseases of the Immune System ......................................................................................... 364
22.3.1 Autoimmune Diseases ........................................................................................... 364
22.3.2 Inl ammation.......................................................................................................... 365
22.3.3 Cancer Immunology .............................................................................................. 365
22.4 Immunosuppressive Agents ................................................................................................ 366
22.5 Immunomodulating Biologics............................................................................................. 368
22.5.1 Recombinant Protein and Engineered Proteins ..................................................... 368
22.5.2 Monoclonal Antibodies.......................................................................................... 369
22.5.3 Cytokines ...............................................................................................................369
22.5.3.1 Interferons .............................................................................................. 369
22.5.3.2 Tumor Necrosis Factor ........................................................................... 370
22.5.3.3 Interleukins............................................................................................. 370
22.5.4 B Cell Depletion..................................................................................................... 372
22.5.5 Targeting T Cells ................................................................................................... 373
22.6 Prospects of Immune Modulating Agents .......................................................................... 373
Further Readings ............................................................................................................................ 373
22.1 INTRODUCTION
The purpose of the immune system is to combat infectious diseases caused by bacteria and viruses;
however, evidence suggests that the immune system plays a central role in protecting the body
against cancer and in combating cancer that has already developed. When the immune system
is weakened, it can be more easily overwhelmed by cancerous cells. Cancer may occur when the
immune system can no longer defend against invading tumor cells. There is evidence in many can-
cer patients that rebuilding the immune system slows down the growth and spread of tumors.
The immune system can also lead to pathological consequences for the individual. The i rst
example is the normal attack of a healthy immune response on a transplant leading to transplant
rejection. The second example is when tolerance to self break downs and self tissues are attacked by
the immune system leading to autoimmune disease. The third example is when the immune system
responds dramatically to otherwise harmless antigens leading to allergy or hypersensitivity.
I m mu nomo du lat i ng agent s ca n b e sepa rat e d i nto agent s t hat suppress or blo ck t he i m mu ne syst em
when it is reacting against self antigens, hyperreacting or in relation to transplantation (autoimmune
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