Somatic Recombination

The cells of the adaptive immune system attack foreign pathogens by producing proteins, such as antibodies, that use a lock-and-key mechanism to recognize pathogenic antigens, or molecules that can elicit an immune response (Figure 1).  In order to defend our bodies against the millions of different pathogens that could harm us, the adaptive immune system … Continue reading Somatic Recombination

Positive and Negative Selection of T Cells

Adaptive immune cells, like T cells, play a critical role in protecting our bodies against invading pathogens, a task that relies upon their ability to recognize pathogens as foreign, or ‘non-self’. This begs the question, though, of how adaptive immune cells distinguish between self and non-self. How is it that T cells know to attack … Continue reading Positive and Negative Selection of T Cells

MHC class I: a novel mediator of the “don’t eat me” signal

In 1909, a German scientist named Paul Ehrlich made a simple yet shocking proposal: that cancer arises in our bodies quite frequently, but that it is usually eliminated by cells of the immune system before tumors form. Although radical at the time, Ehrlich’s theory gained experimental support in the mid-to-late 20th century, and it is … Continue reading MHC class I: a novel mediator of the “don’t eat me” signal