Now from a famous editorial for the journal, Evidence Based Complementary and Alternative Medicine (eCAM
) we have the musings of what is appropriate for creating this linkage between the immune system and CAM. ‘As a developmental immunobiologist, interested in origins and foundations, I am of course steeped in the beginnings of modern immunology. Let us deal in a bit of musing juxtaposing immunology, science and CAM. We can ask the question: ‘Can eCAM
Be Scientific? Lessons from Immunology’. According to Burnet (See 4):
The first objective in a serious approach to immunology should be to obtain a broad understanding, with a minimum of detail, of how immunology fits into the pattern of biology—of the way in which the immune system evolved, its function and coordination with other body systems, and its development from the embryo onwards. At the same time, such an outline should provide an adequate background for easy application of immunological ideas to the detail of practical immunological work in public health, clinical, and veterinary practice.
Would it be possible to paraphrase this statement in the context of eCAM so that it reads: ‘the first objective in a serious approach to CAM should be to obtain a broad understanding, with a minimum of detail, of how CAM fits into the pattern of biology—of the way in which the neuroendocrineimmune system evolved, its function and coordination with other body systems, and its development from the embryo onwards. At the same time, such an outline should provide an adequate background for easy application of CAM ideas to the detail of practical CAM work in public health, clinical and medical practice, and yet not stray far away from the very biology that under girds it. CAM is organismic, inclusive and not exclusive (4).
Now it is appropriate to turn to the next question. Does any of this fit? So how do we define CAM? Readers may be wondering just what is complementary medicine and what is alternative medicine? Several definitions may be offered based on different points of view and those in turn influenced by professional training, practice and, perhaps, the dictates of funding agencies. The discipline is a heterogeneous subject, to say the least, and it is unlikely that all the adherent disciplines that are sheltered by the umbrella of CAM will carry equal weight or influence or can be subjected to the same rigors of scientific inquiry. Some of these generalizations apply to all disciplines, including those subdisciplines that fall under the aegis of the immunology umbrella. However, perhaps CAM is ripe for an infusion of empiricism. Modern immunology, like CAM, has its earliest roots in concerns for health and disease, but immunology never seemed to have been branded with the aura that often shrouds CAM. There were always a group of experimentalists and, perforce, the necessity to use animal models with which experimentation could be performed to test hypotheses (5).
was launched there was a beginning flurry of works devoted to immunity and CAM. The interesting twist concerned an area that seemed to have been the bridge between what was truly primitive of Metchnikoff's heyday and what is truly immune. Enter therefore and only naturally, the NK cell. According to Takeda and Okumura (5
) it has been well known since ancient times that CAM, including exercise, provides a lot of benefit to health. Many CAM modalities are believed to prevent or even cure diseases, especially morbid ones such as cancer and aging (7,8,9,10). However, until recently conventional medicine has largely rejected the use of CAM agents because little biological evidence has been provided for the functional mechanisms of many of them. For the past few decades, many modern scientific researchers have rediscovered the value of CAM. Modulation of immune functions by CAM agents is the mechanism most widely analyzed and has been suggested to provide some scientific evidence for the biological effects of various CAM agents. Specifically, evidence for up-regulation of natural killer (NK) cell numbers and/or NK cell cytotoxicity by these agents has been accumulating. NK cells have been well established as innate cytotoxic effector cells for self-defense in both vertebrates and invertebrates, in both of which they may use similar mechanisms in the lysis of target cells.
Takeda and Okumura (1
) further point out that ever since Macfarlane Burnet proposed the immune surveillance hypothesis against tumor development, the concept has been a hot focus of debate for more than 40 years. The original immune surveillance hypothesis was challenged because nude mice lacking T cells did not show a higher incidence of cancer than did syngenic immunocompetent mice. However, this contradictory conclusion is now taken as fine evidence that innate immunity is in the critical arms of immune surveillance against tumor development. Moreover, in the innate immune system NK cells, which do not express TCR that recognize specific peptides presented on the major histocompatibility complex (MHC), rather than T cells, seem well suited for this role. NK cells thus mediating natural cytotoxicity are composed predominantly of large granular lymphocytes (LGL) and some of small agranular lymphocytes, both of which express CD16 and CD56, but no T-cell receptor on the cell surface. NK cells can induce cytolysis in the absence of MHC class I antigen expression on their target cells. This phenomenon is commonly understood according to the ‘missing self’ hypothesis. Culture of NK cells with some cytokines augments their cytotoxic activity so that they become able to induce cytolysis for a wide spectrum of cells, including tumor cells expressing autologous MHC class I. They are now called lymphokine-activated killer (LAK) cells, although LAK cells are also induced by T lymphocytes.