As a member of the immunology community, I like to think of our publications as a coherent, albeit forever incomplete, structure of extraordinary beauty. Most of us have contributed to the bricks and mortar that constitute the readily visible essence of the structure (that is, the majority of the papers between the covers of our journals). Within most issues, we also find windows of new insight that illuminate the interior. Then there are those critical but rare constituents, the supporting pillars upon which the construction of the structure depends.

With this issue of The Journal of Immunology, we introduce a new feature that will focus on the pillars. This will be a monthly reprinting of papers that the editors believe have had uncommon influence on the underlying structure of our edifice. We will call these “Pillars of Immunology.” The identification of such papers is both a daunting challenge and an immensely enjoyable experience. In re-reading many of the papers, those of us who are properly regarded as senior citizens in the discipline will have an opportunity to relive moments of excitement from our scientific youth.

The more important goal of this effort is directed to those of you who come more recently to immunology. Although the essence of these papers will by now have found its way into reviews and textbooks, these are papers that we believe worthy of reading in original form—sometimes to appreciate not only the accomplishments of the authors, but also to understand how our interpretation of observations may change with new discoveries.

In general, we are taught the fundamentals of a discipline by asking, “What do we think we know and on what evidence do we base this knowledge?” It is less frequent that we deal with a retrospective question such as, “What did they think they knew and why?” And extending further, “How did what they learned affect what we know now?” It is in approaching the latter issues that we gain understanding of the infrastructure of our discipline. Additionally, I believe it is useful to appreciate the extent to which progress in immunology has involved approaches and technologies that are today commonplace, but that often had arduous origins. In retracing that journey from arduous to commonplace, we find a recurring theme. That which was hard may become commonplace, when it is truly important; it stimulates us to innovate and to work together, often across disciplines, making what was difficult easier—thus adding the bricks and mortar.

Initially, papers have been chosen for inclusion in this series based on a nomination by one or more of The JI editors. To provide sufficient distance in time for perspective, while assuring that the papers are still relevant to present issues, editors were asked to nominate papers that had been published between 15 and 40 years ago. Some of the papers have been published in The JI; the rest were published in other journals that have granted us permission to reproduce their copyrighted material. In all cases, the papers will be accompanied by an introduction that places the paper in context at the time of publication, and provides a rationale for its reprinting more than a decade later.

I have chosen to inaugurate the series with a paper published in The Journal of Immunology near the beginning of our (arbitrary) 40-year window. A publication by Henry Claman and colleagues in 1966, which demonstrated a role for thymus-derived lymphocytes in the production of Abs, is accorded this distinction. The collaboration of T and B cells in generation of most Ab responses is now a common feature of introductory lectures and chapters in immunology, but it was experiments such as those described by Claman et al. that shed early light on this phenomenon. Several additional papers from The JI have also been chosen for this honor. Nevertheless, it is our intent to include in this series publications from wherever we find them (subject, of course, to permission from the copyright holder).

Are there common distinguishing characteristics of a “Pillar?” Although virtually all of the papers chosen for inclusion will have had an exceptional citation frequency, we have chosen not to use this feature as an arbitrary defining characteristic. Generally, they should be papers that in some way changed the way we thought about a problem or its solution. It may be a new technical approach, a novel insight in experimental design, the execution of a particularly challenging experiment, or an interpretation that proved especially prescient. Most will have had a broad impact on the field of immunology; some will have had a narrower but profound effect on a particular area. For many, the impact has been both broad and deep. In most cases, such landmark papers are distinguished by clarity of expression in reporting, both of the data and in its interpretation.

Will all of the papers chosen for reprinting today be similarly regarded as classics 15 years from now? Probably not—that is part of the price paid for an effort to judge relevance over a relatively brief distance in time. We consistently see our own history through the distorting prism of present experience.

Will we omit papers that deserve to have been chosen? Of course—that is part of what makes the venture daunting. It is also inherent in the decision, at least initially, to limit publication to one paper per month. However, our first solicitation of journal editors provided dozens of candidate suggestions.

Will all of you concur with our choices? I rather doubt it. However, I am confident that you will find worthwhile the experience of reading (or re-reading) the selected papers. I look forward to hearing from you as this new venture unfolds. Finally, although our early course has been set, I will welcome suggestions from all the readers of The JI for future choices in this distinguished series. Enjoy.