Advertisement

How do the innate and adaptive immune systems work together?

Anthony L. Komaroff, MD
Internal Medicine
The innate immune system tells the adaptive immune system when it's time to help mount a defense. It does this by posting two types of changes on the phagocyte surface that activate the adaptive immune system. These changes are necessary for full immune system activation.

The phagocyte is also known as an antigen-presenting cell because after engulfing the invading microbe, it displays pieces of protein from the microbe, called antigens, on its surface, on what is known as the major histocompatibility complex (MHC) molecule. This alerts the adaptive immune system and allows cells known as T cells to recognize an infected cell.

Yet that is not enough to trigger the full adaptive immune response. There also needs to be a danger signal or flag displayed on the surface of the cell to call the adaptive immune system into action. This is the job of proteins called pattern-recognition receptors (PRRs). Found on or inside phagocytes, PRRs recognize general groups of microbes that have common traits. They set in motion a sequence of cellular events that results in posting the flags required to trigger an adaptive immune response. They also release a family of chemical messengers called cytokines to call the adaptive immune system into action.

Continue Learning about Immune System

Kick Immunity into High Gear with a Kicky Song
Kick Immunity into High Gear with a Kicky Song
Ever catch yourself humming that old Broadway tune "Everything's Coming Up Roses"? Maybe you should give it a try sometime. Your immune system may tha...
Read More
What is the difference between innate and adaptive immune systems?
HealthyWomenHealthyWomen
The difference between the innate and adaptive immune systems has to do with how they work. The inna...
More Answers
What are antibodies?
Brad J. Spellberg, MDBrad J. Spellberg, MD
Antibodies are proteins produced by specialized immune cells called B lymphocytes. Each B cell produ...
More Answers
Can I Improve My Immune Cells to Fight Cancer?
Can I Improve My Immune Cells to Fight Cancer?

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.