Revisiting T cells: Innate actions and emerging links to innate memory response

The traditional view of the immune system distinguishes between the innate immune system, which serves as the host's first line of defense against pathogens, and the adaptive immune system, which evolved to manage more complex or recurrent infections. However, the discovery of evolutionarily conserved mechanisms in innate memory cells (trained immunity) has revealed adaptive-like characteristics in innate immune cells, challenging the conventional dogma between innate and adaptive immunity. Simu