An immune response based on directed amplification of specific receptors for antigen produced through a somatic diversification process that includes somatic recombination of variable lymphocyte receptors (VLR) incorporating leucine-rich repeat (LRR) domains, and allowing for enhanced responses upon subsequent exposures to the same antigen (immunological memory). Examples of this process are found in jawless fish, including the lampreys (Petromyzontidae) and hagfishes (Myxinidae).