At the heart of our bodies’ defence system is the ability to recognise any foreign proteins that could ever exist, even ones that evil scientists haven’t thought of yet.
The recognition of foreign proteins is by intelligent design and comes from living cells. This extraordinary capability is largely accomplished through a process known as VDJ recombination.
Variable diverse joining (“VDJ”) recombination is the process by which immunoglobulin (antibody) and T cell receptor genes are assembled into functional units during lymphocyte (a type of white blood cell) development. This process is crucial for the adaptive immune system, producing a diverse set of antigen receptors in developing lymphocytes.
Virtually any substance can elicit an antibody response. Furthermore, the response even to a simple antigen bearing a single antigenic determinant is diverse, comprising many different antibody molecules each with a unique affinity, or binding strength, for the antigen and a subtly different specificity. The total number of antibody specificities available to an individual is known as the antibody repertoire, or immunoglobulin repertoire, and in humans is at least 1011 (that’s 10 followed by 10 zeros or 100 billion), perhaps many more.
Diversity within the immunoglobulin repertoire is achieved by several means. Perhaps the most important factor that enables this extraordinary diversity is that V regions are encoded by separate gene segments, which are brought together by somatic recombination to make a complete V-region gene. Many different V-region gene segments are present in the genome of a person, and thus provide a heritable source of diversity. Additional diversity, termed combinatorial diversity, results from the random recombination of separate V, D, and J gene segments to form a complete V-region exon....<<<Read More>>>...
