Brave new immunology

View Large Image | Download PowerPoint SlideThe first self-declared ecoimmunology textbook has succeeded in a difficult task: thoughtful integration of multiple disciplines of biology, some of which tend to work at cross-purposes. The edited volume comprises 19 chapters aimed at researchers who study immune defence in an evolutionary context, and particularly in the context of life-history theory, as articulated by Ben Sheldon and Simon Verhulst in a now-classic paper in TREE over 15 years ago [1xEcological immunology: costly parasite defences and trade-offs in evolutionary ecology. Sheldon, B.C. and Verhulst, S. Trends Ecol. Evol. 1996; 11: 317–321Abstract | Full Text PDF | PubMed | Scopus (1274)See all References][1]. The core issue of ecoimmunology is to explain the adaptive significance of heterogeneity in immune defence, in light of life-history and resource trade-offs surrounding somatic maintenance (to which immunity is expected to contribute) versus growth and reproduction (from which immunity is expected to detract) [1xEcological immunology: costly parasite defences and trade-offs in evolutionary ecology. Sheldon, B.C. and Verhulst, S. Trends Ecol. Evol. 1996; 11: 317–321Abstract | Full Text PDF | PubMed | Scopus (1274)See all References, 2xOptimal immune responses: immunocompetence revisited. Viney, M.E. et al. Trends Ecol. Evol. 2005; 20: 665–669Abstract | Full Text | Full Text PDF | PubMed | Scopus (166)See all References]. An ecoimmunology textbook poses a difficult task because of the struggle to delve adequately into both the ‘hows’ and the ‘whys’ of that core issue; that is, how immune systems work, and why, evolutionarily, they work as they do. It is by striking a balance between hows and whys, above all, that Ecoimmunology succeeds.As I read, I was struck by many positives. For example, there is sound, realistic representation of infectious disease throughout: nearly all chapters address infection explicitly, which may be a sign that ecoimmunology is indeed becoming as connected to disease ecology as it should be [3xDisease ecology meets ecological immunology: understanding the links between organismal immunity and infection dynamics in natural populations. Hawley, D.M. and Altizer, S.M. Funct. Ecol. 2011; 25: 48–60CrossRef | Scopus (100)See all References][3]. Physiology and behavior are both well represented, and the authors have interestingly varied definitions of ecoimmunology. Furthermore, descriptions of mechanistic molecular and cellular details are nicely couched within ecological and evolutionary hypothesis tests, providing motivation for a TREE audience to embrace such details, or, at least, to persist despite the siege of acronyms that immunology inevitably entails. Reprinted original data figures provide welcome illustrations, and the schematic diagrams of immunological pathways provide insight without swamping readers in complexity. I think it is also safe to say that this is the first immunology textbook in the world to boast an adorable cover image.I did also find modest negatives. For example, invertebrates are under-represented and, in several places, authors present putative costs of immunity without any consideration of countervailing costs of parasitism. Throughout the book, conceptual figures (e.g., Venn and flow diagrams) are unimaginative and often text laden, so they convey the underlying ideas poorly. These are so pervasive that it seems they may have been forced upon the authors. This lapse is unfortunate and may mean that the potential audience will be more restricted than need be (especially problematic for newcomers to ecological and evolutionary immunology).However, my overriding impression was of well-grounded conceptual synthesis. The melding of immunological and evolutionary ideas serves to inspire, whereas the liberal acknowledgement of complexity and confusion in the literature, and the limits of assays and/or generalizations across taxa, serve to ground the book empirically. In particular, there is consensus among chapters that one-size-fits-all immune assays are not feasible. This is because different assays capture such different aspects of immunity that an assay drawn at random from the millions of possibilities is unlikely to be relevant to any given evolutionary hypothesis. Therefore, the book makes a strong case that the ‘hows’ and the ‘whys’ of immunity both matter. It should spark a great deal of research effort, including selection of empirical measurements that are more consistently relevant to the organisms or life-history traits under study.Thus, Ecoimmunology (like [4xBrave New World. Huxley, A. See all References][4]) does not present a dystopia with uncritical examination of where things stand. This truly is a brave new immunology. Indeed, whether wild [5xWild immunology. Pedersen, A.B. and Babayan, S.A. Mol. Ecol. 2011; 20: 872–880CrossRef | PubMed | Scopus (74)See all References][5], uncaged [6xBiomedical research. Immunology uncaged. Leslie, M. Science. 2010; 327: 1573CrossRef | PubMed | Scopus (9)See all References][6], or ecological [1xEcological immunology: costly parasite defences and trade-offs in evolutionary ecology. Sheldon, B.C. and Verhulst, S. Trends Ecol. Evol. 1996; 11: 317–321Abstract | Full Text PDF | PubMed | Scopus (1274)See all References, 7xAn introduction to ecological immunology. Martin, L.B. et al. Funct. Ecol. 2011; 25: 1–4CrossRef | Scopus (44)See all References, 8xIntroduction. Ecological immunology. Schulenburg, H. et al. Philos. Trans. R. Soc. Lond. B: Biol. Sci. 2009; 364: 3–14CrossRef | PubMed | Scopus (132)See all References], immunology is on the move, with recognition of the importance as well as the increasing feasibility of studying: (i) proper immunological mechanisms operating in nature; and/or (ii) genetic and ecologically induced variation in the laboratory. I am heartened by this book. I keenly await the future discoveries that are made possible by its synthetic and empirically grounded approach to the evolutionary ecology of immune defence.