Some Terms from Immunology I

About a week ago I went to lunch with a person who has been encouraging me to do some autism-related research for a while. We finally settled on a task which delighted me--to learn about various biological treatments for autism (dietary, supplements, chemical treatments) that had some track record of success and then write a book for lawyers/judges which explains this complex but valuable world. In order to do so, I have had to begin immersing myself in loads of scientific disciplines, such as biology, biochemistry, immunology, toxicology and several others, in order to learn how the effects of various deficiencies in bodily systems might provide the context for or function as environmental "triggers" for autism.

Whenever I face the daunting task of learning new disciplines, I take two approaches: (1) a historical one, where I learn about the people who developed the field and exactly what they had done and thought they had done; and (2) a lexicographic one, where I begin to learn the vocabulary of the field and understand the "pictures" that are created in mind through the use of new vocabulary. So, as I immerse myself into the field of immunology, I have come across tons of terms, many of them new to me, which define the field. In fact, I think the filed has so many terms that I bet people in the field get confused all the time--but that is a story for another essay.

The reason I do these rather "bite-sized" tasks is that brief descriptions of the entire immune system I have read are so brief that they invite dozens of questions that they don't attempt to resolve, and textbook descriptions of the field often lose themselves in verbiage which is not efficiently or clearly communicated (see this essay). Thus, we take one piece of knowledge at a time, and then gradually begin to piece together the field. That is the way to study.

The Barest Primer on the Immune Systems

Before we look at some interesting words in the field, I should say a thing about immunology itself. The field is divided into two systems--the study of the innate immune system and the adaptive immune system. The former is what is referred to as a "non-specific" responder--it consists of quick and targeted responses to pathogen intrusion, responses that usually consist of eating the invading pathogens (a process known as phagocytosis). But this generic or "non-specific" system not only can't "tailor" its response to specific antigens (let's say that antigen and pathogen are synonymous, for this consideration), but it has no memory of what it has done. Like a modern-day Agave (mother) who, in Euripides' Bacchae just cuts off the head of her son Pentheus while she is under a religious spell, and then parades around town with the head without knowing what she has done, so the non-specific "eaters" (the leading two are called macrophages and neutrophils), just eat and have no memory of what they have done.

Memory is one of the purposes of the adaptive immune system. But before I mention this latter system, I should say that the non-specific immune system also consists of what is called complement. This is a tricky concept, and I don't really believe that immunologists know quite how to explain it completely, but it is a response of a "protein cascade" (I love the latter word, since I have lived about 60 miles from the Cascade Mountains for nearly 20 years) that leads to all kinds of splitting of proteins that eventually defeats the invading antigens.

Well, the other immune system is our adaptive immune system. The difference between this system and the innate system can be illustrated by the difference between buying an "off the rack" and "custom-made" suit. In the former, you just buy it, with alterations taking a few days. In the latter case, however, you may have to wait a few weeks for it to be made to your "specs." So, the adaptive system is "tailor-made" to the specific threat posed by the invading antigen. It develops the precise antibody to meet the invader, sort of like a partner that destroys you (that may be too close to home for some of you...). This takes a while--maybe a week or more for the adaptive system to kick in. But some the cells of the adaptive system also have the capacity to develop memory--so as to aid them in springing into action in a future instance. As you might imagine, much more could be said about this latter system--which consists of the "cell-based" immune system (the "T-cells") and the "humoral based" immune system (the "B-cells"). Stories abound about naming of these cells, the mechanisms that trigger their action, the "pathways" they pursue and their ability to help you out. I am learning so much every day. I look forward not simply to learning almost all the important terminology of the field, but to look at the verbal maps presenting the immune system as linguistic systems that can lead to questioning of and improving the system even without having worked in the field at all. That is, systems must hold together linguistically in order for them to make sense. If they don't, then something is "missing." I hope to help develop those "missing" things, even though I have never looked through an electron microscope.

Some Words To Be Defined--and a Word on Pictures

So, in the next two essays I will try to define some of the following terms: apoptosis, opsonization, mercaptan, alexin, interleukin, amboceptor, phagocyte, phagolysosome, lysosome, mitochondria, endocytosis, epitope, zymogen and anergy. A knowledge of these terms won't get you too far, but it will lead you to other terms and, before you know it, you will be on a journey from which you may never want to turn back.

But before I do this I need to confront one little problem that is already developing as I study immunology--and that is the question of whether all the nice diagrams and pictures I see actually represent what is taking place on a molecular level. The issue has been controversial one for a long time, and the issue was brought to a head in a 1993 essay in Isis, "Ehrlich's 'Beautiful Pictures' and the Controversial Beginnings of Immunological Imagery," (Dec. 1993, pp. 662-699). The thesis of this article, by Alberto Cambrosio, Daniel Jacobi and Peter Keating, is that Ehrlich's immunological theories, first articulated in the early-mid 1890s, "took off" in popularity after his publication, in 1900, of several pictures which claimed to represent his "side-chain" theory of antibody formation. The thesis is that once pictures enter into the equation, the field is shaped not simply by chemistry but also by art. Thus, even the most apparently scientific fields, which are depicted pictorially, will eventually have to contend both with formulaic or "scientific" activity as well as the visual representations of what is being described.

Conclusion

Thus, as I investigate a new field, I do so with a fesh sense of discovery and absolutely no fear. The terms can be explained; lives of scholars can be understood; pictures can be critically examined; logical gaps can be identified; the field can then advance. Let's take the first step in the next essay.

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