Me or not me?

The biological definition of ‘me’-ness or individuality finds the immune system as a key determinant. As both in physiological and philosophical contexts the immune system provides a principle of exclusion whereby one can define what is ‘self’ and what is ‘nonself’. Description of the ‘physiological me’ saw an incremental evolution of the conception starting from the original ‘Self-Nonself Theory’ of Peter Medaware and Frank Burnet (1959), through interim modifications offered by Melvin Cohn (1969), Kevin Lafferty & Alistair Cunningham (1975), to the ‘Infectious Nonself Theory’ of Charles Janeway (1989) and then the ‘Danger Model’ as conceived by Poly Matzinger (1994) followed by the ‘Antigenic Continuity’ model proposed by Thomas Pradeu (2013). In the philosophical context the dominant idea has been that the immune system is instrumental in the advent of multicelullar life. As with the advent of multicellularity there is conflict of Darwinian individuality among the individual cells, an intra-organismal surveillance system has to exist to get rid of individual cells that refuse to relinquish their claim to Darwinian fitness. The immune system has been shown to be capable of providing such a surveillance system as evident from experimental data from Dictyostelium (Adam Kuspa, 2007) and cancer immunosurveillance in mammals (Robert Schreiber, 1999). Extension of this idea to every level of biological individuality also gains approval as immune mechanisms are described in a single cell (CrispR system) as well as supra-organismal social insects (James Traniello, 2002). Thus the existing experimental data and conceptual thoughts point to a key role of the immune mechanisms as the determinant of biological individuality.