A Journey with Elie Metchnikoff: From Innate Cell Mechanisms in Infectious Diseases to Quantum Biology

Abstract

Many reviews of Elie Metchnikoff's work have been published, all unanimously acknowledging the significant contributions of his cellular theory to the fields of immunology and infectious diseases. In 1883, he published a key paper describing phagocytic cells in frogs. His descriptions were not just about phagocytes involved in host defense, he also described how these specialized cells eliminated degenerating or dying cells of the host. This perspective focuses on key concepts developed by Metchnikoff by presenting relevant excerpts of his 1883 paper and matching these concepts with challenges of modern immunology. A new approach to macrophage polarization is included to introduce some creative thinking about the exciting emerging area of quantum biology.

Keywords: Metchnikoff; infection; inflammation; innate immunity; macrophage; polarization; quantum biology.

Figure 1

Graphical representation of the boundary between innate and adaptive immune systems over time from Metchnikoff’s era to modern immunology. The plain line in (A) highlights a clear dichotomy with no connections between the two systems. Then, the line becomes broken (B) and sinuous (C) evidencing opposite forces from both sides based on scientific breakthroughs. Once researchers have come to a mutually agreed standby point, equilibrium is reached. As more scientific data are available, connections between innate and adaptive systems (D) become obvious with areas of similarities or convergence represented by black circles (e.g., complement). This convoluted boundary is not definitive yet as it becomes more permeable (E) allowing, in some specific places (yellow spheres), communication (gray arrows) between innate and adaptive immune systems (e.g., memory NK cells, cytokines) introducing more flexibility and complexity.