President Cantarovich, Members, and Guests Firstly, I must thank the Medawar Prize Selection Committee and The Transplantation Society for this incredible honor. I am delighted to be sharing this recognition with Professor Jeremy Chapman, a much-admired colleague, and a dear friend. I must thank Professor Jean Paul Soulillou for my nomination and the distinguished scientists who supported my candidacy. Last but not least, I must also thank Professor John Gill for his laudatory introduction. I have been extraordinarily fortunate in many ways: I was very blessed to have had parents whose highly principled lives have served as my guiding lights. I am very fortunate to be married to Dr Phyllis August, an exceptional physician-scientist in her own right, who continues to be an inspiration in every aspect of my life. THE BRIGHAM YEARS A remarkable set of fortunate circumstances and enthusiastic endorsement by Dr. Franklin D McDonald, the erudite Chief of Nephrology at Wayne State University, gained my admission to the Nephrology Fellowship at the Peter Bent Brigham Hospital in Boston. When I joined the Brigham in the mid-70s, Dr John Merrill was the inspirational chief of the Cardio-Renal division. Dr Charles Bernard (Bernie) Carpenter, the ultimate gentleman scholar, was the Director of the Immunology Laboratory. I was assigned to work with Dr Marvin Garovoy who had just returned to the Brigham to head the Tissue Typing Laboratory housed at the Brigham. Terry Strom, then a young faculty member, had a magnetic presence in the Carpenter laboratory, and we had an enduring professional and personal relationship including some highly competitive tennis matches at Terry’s club! My cofellows were exceptional, exemplified by Jean Paul Soulillou, an earlier recipient of the Medawar prize. I learned much from an eclectic group of highly gifted fellows: Graeme Catto, Tony D’Apice, Peter Gailiunas, Harold Helderman, Antoine Kaldany, Gill St. Louis, Peter Lundin, Edgar Milford, and Douglas Norman. My assignment to the Brigham Tissue Typing Laboratory under Marvin’s tutelage turned out to be a propitious one for my introduction to, and education in the fast-evolving field of human immunogenetics. It provided a foundation enabling me to develop the Immunogenetics laboratory in NY with an authentic pioneer in the Tissue Typing world, Dr Marlina Fotino, MD, PhD. We initiated the laboratory in 1985, and over the years, the clinical laboratory has evolved to serve >20 academic transplant programs in the Greater New York area and importantly facilitated the performance, in the past decade alone, of >10 000 solid organ transplants. In the innovative and inspirational environment of the Carpenter laboratory, I miniaturized the sheep red blood cell rosetting technique so that human T cells could be robustly identified by adopting microtiter plates used in the Tissue Typing laboratory to perform HLA typing and complement dependent cytotoxicity crossmatches. Utilizing the microtiter plate, I found that antibodies to human Ia antigens (now major histocompatibility complex class II) inhibit Fragment, crystallizable receptor binding and that these antibodies are associated with acute rejection and inferior survival of human kidney allografts. Benefitting from the outstanding technical expertise in the Carpenter Laboratory, I was also able to elute anti-Ia antibodies not only from the rejecting rat kidney allografts but also from rejected human kidney allografts. These were the original sparks for my life-long research efforts in the immune monitoring of allograft recipients. THE MOVE TO BIG APPLE From the Brigham, I was recruited to the Rogosin Kidney Center, Cornell University Medical College, and The New York Hospital in 1977 to initiate and develop transplantation research and clinical laboratories to support the mature clinical transplantation program already in place. The micro-rosette technique I had developed played a pivotal role in my recruitment since anti-thymocyte globulin was being considered as induction therapy and the deletional effect of anti-thymocyte globulin on T cells was then being monitored by sheep red blood cells resetting using large volumes of blood. I have remained at Cornell ever since and through my institution’s reincarnation as The NewYork-Presbyterian-Weill Cornell Medicine. My uninterrupted tenure has served me and my team well in accomplishing our body of basic and translational research (Table 1). TABLE 1. - A summary of scientific discoveries and (publications) from the Suthanthiran laboratory at Weill Cornell Medicine • Formulation of a human T-cell activation model wherein T-cell costimulatory signal is generated by the physical interaction between the CD2 protein on the T-cell surface and its counter receptor on antigen-presenting cells (J Leukocyte Biology 1985, J Exp Med 1990). • Identification of hydroxy radicals as mediators of natural killer cell cytolytic activity (Nature 1984). • Induction of alloantigen-specific secondary cytolytic activity by transmembrane signaling via T-cell CD3 epsilon chain on human memory T cells (JCI 1984). • Discovery of a cell surface version of tumor necrosis factor alpha on activated human T cells (J Exp Med 1990). • Identification of TGFB1 induction by cyclosporine (J Exp Med 1991). • Discovery of cell autonomous mechanism for cancer progression via cyclosporine-induced TGFB1 (Nature 1999). • Invention of urinary cell gene expression profiling methodology and development of noninvasive biomarkers of allograft rejection, tolerance, and a means for assessing in vivo immune status of organ graft recipients (N Engl J Med 2001; N Engl J Med 2005; N Engl J Med 2013). • Genome-wide transcriptomics and deciphering unique and shared gene sets and pathways of T-cell–mediated rejection and antibody-mediated rejection and demonstration that urine is an excellent surrogate for the invasive allograft biopsy to interrogate human kidney allograft status (JCI Insight 2020). TGFB1, transforming growth factor beta 1. UNRAVELING THE SECRETS OF MOTHER NATURE T-cell activation and antigen-specific clonal expansion are fundamental to both rejection and tolerance. One of our earliest and clinically significant research findings was our formulation of a new human T-cell activation model. When we initiated our studies, the prevailing dogma was that the costimulatory signal for T cells was provided by the monokine interleukin-1. Our studies shifted the paradigm from interleukin-1 as the T-cell costimulator to a T-cell activation model wherein the physical interactions between T-cell CD2 antigen and its counterreceptor on the antigen presenting cell, latter identified as lymphocyte function associated antigen 3, form the supramolecular clusters essential for transmembrane signaling of T cells. This novel concept for T-cell costimulation was first reported by my laboratory in 1985 in the Journal of Leukocyte Biology, almost 4 y before CD28 was advanced as a T-cell costimulatory molecule, and was minimally acknowledged in the literature until a more elaborate model was described by us in the Journal of Experimental Medicine.1 We went on to demonstrate that targeting the CD2 protein induces transplantation tolerance in a preclinical model. I was particularly thrilled to note that the Massachusetts General Hospital/Harvard team brilliantly accomplished tolerance to one haplotype-matched kidney allografts using a preconditioning regimen that included antibodies directed at the T-cell CD2 protein. Natural killer (NK) cell cytolytic activity is an essential constituent of host defense systems and is increasingly implicated in determining the fate of allografts. We investigated the cytolytic programming of this enigmatic cell population, and we focused on reactive oxygen intermediates in view of their role in host defenses mediated by professional phagocytic cells. We discovered that hydroxyl radicals are nonredundant mediators of NK cell cytotoxicity since hydroxy radical scavengers—dimethyl sulfoxide, thiourea, dimethyl urea, tetramethyl urea, benzoic acid, ethanol, methanol, and ethylene glycol-inhibited NK cell cytolytic activity.2 A potential source of hydroxyl radical is the univalent reduction of molecular oxygen. We therefore examined whether catalase, a scavenger of hydrogen peroxide, and superoxide dismutase, a scavenger of superoxide radicals, either alone or in combination, inhibit NK cell cytotoxicity. Whereas neither did, arachidonic acid metabolism via the lipoxygenase pathway was a source of hydroxyl radicals. Our deciphering of NK cell effector activity offers an underappreciated pathway to regulate NK cells central to host defense including tumor immunity and transplantation immunity via the missing-self pathway and likely involving the Fc receptors displayed on NK cells. In additional studies of cytolytic activity programming, we found that transmembrane signaling via the T-cell CD3E chain results in the induction of antigen-specific secondary cytolytic activity and NK cytolytic activity, whereas neither signaling via CD4 or CD8 proteins induce such cytolytic activity.3 This augmentation of secondary cytolytic activity and NK cell activity was target cell-specific and was not associated with cytotoxicity to syngeneic or third-party allogeneic peripheral blood mononuclear cells. NK cell activity mediated by peripheral blood mononuclear cells from immunodeficient individuals was also significantly augmented by CD3E signaling. The clinical significance of our discovery includes: Blocking the CD3 signaling pathway may prevent graft destructive alloimmune responses, and stimulation via CD3 could enhance the T-cell memory response and restrain tumor progression in a more antigen-specific fashion than the checkpoint inhibitors and potentially augment responses to repeat vaccination (eg, COVID booster vaccine). An intriguing mechanism for the expression of antigen-specific cytolytic activity involving circulating cytokines was also discovered in our studies of cytolytic activity of T cells. Tumor necrosis factor alpha (TNFA) is widely recognized as a circulating cytokine, and its specificity was understood to be based on receptors for TNFA. Our studies identified a cell surface version of TNFA on the surface of activated T cells.4 This novel finding uncovered a new mechanism for delivering TNFA in an antigen-specific fashion. Preventing antigen-specific delivery of TNFA should benefit organ graft recipients and patients with autoimmune diseases including type 1 diabetes, psoriasis, and rheumatoid arthritis. Cyclosporine and tacrolimus have had a transformative impact on organ transplantation. The ability of calcineurin inhibitors (CNIs) to block a panoply of proinflammatory cytokines is a well-recognized mechanism of action of both cyclosporine and tacrolimus. We discovered a unique mechanism of action of CNIs. With the use of novel DNA constructs in the competitive quantitative polymerase chain reaction (PCR) assay, and accessory cell-independent T-cell activation models, both developed in our laboratory, we discovered that cyclosporine stimulated, rather than inhibited, the expression of transforming growth factor beta 1 (TGFB1) in multiple cell types including renal tubular cells, T cells, and tumor cells.5 TGFB1 is a potent anti-inflammatory and profibrotic cytokine. The clinical implications of our discovery include: TGB1 inhibition may help reduce CNI-associated fibrosis representing a mechanistically sound strategy for blocking tumor metastasis dependent on tumor cells secreting TGFB1 in response to CNIs.6 This novel cell autonomous mechanism for heightened malignancy associated with TGFB1 was suggested by our findings and showed that cyclosporine conditioning of A-549 adenocarcinoma cells results in striking morphological alterations, including membrane ruffling and numerous pseudopodia, increased cell motility, and anchorage-independent (invasive) growth. These changes were prevented by treatment with monoclonal antibodies directed at TGFB1. In vivo, cyclosporine enhanced tumor growth in immunodeficient severe combined immunodeficiency-beige mice and anti-TGFB1 monoclonal antibodies but not control antibodies prevented the cyclosporine-induced increase in metastases. Altogether, our findings suggest that immunosuppressants like cyclosporine can promote cancer progression by a direct cellular effect that is independent of its effect on the host’s immune cells and that CNI-induced TGFB1 production is involved in metastatic tumor progression. Allografts are ever at threat for rejection. Development of noninvasive and mechanistically informative probes offer the unique opportunity to interrogate allograft status repeatedly, capturing the kinetics of the immune response and personalize immunosuppressive therapy. Toward these objectives, we invented urinary cell messenger RNA (mRNA) profiling and tested the hypothesis that urinary cell mRNA profiles offer a noninvasive means of diagnosing acute rejection in kidney allografts. We designed, developed, and validated gene-specific DNA constructs for absolute quantification of mRNA copy numbers and demonstrated for the first time that measurement of urinary cell mRNA encoding cytotoxic proteins perforin and granzyme B offers a noninvasive means of diagnosing acute rejection.7 RNA isolation from a urine specimen is technically challenging. An innovation that overcame the limited RNA yield from the urine was our incorporation of the preamplification step in the PCR assay. We also overcame the inherent limitations of widely used relative quantification of transcripts in the PCR assay by the development of a universal, custom designed Bak amplicon for absolute quantification of mRNA copy numbers in the preamplification enhanced quantitative real time quantitative PCR assay developed in my laboratory. These refinements led to the discovery that urinary cell abundance of forkhead box protein 3 mRNA discriminates reversible from nonreversible T-cell–mediated rejection (TCMR), prognostic of kidney allograft survival following an episode of TCMR.8 Viewed through the lens that even the biopsy features may not predict TCMR reversal, forkhead box protein 3 mRNA profile could serve as a prognostic biomarker while providing an opportunity to personalize TCMR therapy. Our findings also provided a mechanistic basis for the infusion of regulatory T cells to quench the anti-allograft response and anticipated regulatory T-cell therapy in allograft recipients by at least a decade. Our single center urinary cell mRNA profiling studies paved the way for the multicenter Clinical Trials of Transplantation study-04. In this largest-to-date study of urinary cell mRNA profiling, 4300 urine specimens from 485 kidney allograft recipients were profiled in my Gene Expression Monitoring Core at Weill Cornell. Patients were prospectively enrolled in 5 academic transplant centers, urine specimens were profiled by investigators masked to the clinical and biopsy findings, and data analysis was performed by an independent National Institutes of Health statistical core. The study, in addition to validating the diagnostic utility of urinary cell level of mRNA for granzyme B, perforin, interferon gamma inducible protein 10, and forkhead box protein 3, developed and validated a urinary cell 3-gene signature of CD3E mRNA, interferon gamma inducible protein 10 mRNA, and 18S ribosomal RNA diagnostic of TCMR9. The parsimonious 3-gene signature was predictive of future episodes of TCMR and provided a direct measure of risk (the predicted probability that a biopsy would reveal TCMR) and a means of assessing in vivo immune status with repeated assessments. RNA sequencing is a powerful molecular tool for the unbiased characterization of genome-wide transcriptional changes, deciphering pathogenetic pathways, and helping to prioritize molecular diagnostic and therapeutic biomolecular targets. From our earlier hypothesis-based interrogation of kidney allograft status, we performed, in a first-in-its-kind investigation, genome-wide transcriptomics by RNA sequencing of urinary cells and kidney allograft biopsies and deciphered unique and shared gene sets and pathways of TCMR and antibody-mediated rejection in human kidney allografts10. Of significant value for noninvasive biomarker development was our finding that the mRNA signatures detected in rejecting kidney allografts are enriched in urinary cell gene expression patterns and that the immune landscape is stronger and more diverse in urinary cells than in kidney allograft biopsies. Altogether, RNA sequencing of kidney allograft biopsies and urinary cells, in addition to providing key mechanistic insights, provided direct proof that urine is an excellent surrogate for the invasive allograft biopsy to interrogate human kidney allograft status. The American poet laureate Robert Frost penned the iconic line—We have ideas that we have not tried yet. Here, I have tried to provide an overview of the ideas we have experimentally investigated in my laboratory. A perceptive reader, like the readers of this Journal, would have readily discerned our research focus on human T cells, from developing sheep red blood cells micro-rosette methodology to identifying human T-cell costimulation via CD2 protein and its counter receptor on antigen presenting cells, induction of alloantigen-specific cytolytic activity by transmembrane signaling of memory T cells via the CD3E chain, the versatile T cells displaying TNFA on the cell surface upon stimulation, the widely used CNIs uniquely stimulating TGB1 production, and the diagnostic and prognostic T-cell molecular signatures in urine from patients with rejecting kidney allografts (Table 1). Table 2 is an incomplete list of the gifted colleagues who helped uncover few of the secrets of T and NK cells! TABLE 2. - A list of contributors to the scientific discoveries listed in Table 1. Essa Abuhelaiqa, MD Sandip Kapur, MD Fumi Nakajima, MD Cheguevara Afaneh, MD Milan Kinkhabwala, MD Rubina Naqvi, MBBS, MD Mohamad Alkadi, MD Juhi Kumar, MD Thalia Salinas, MD Dany Anglicheau, MD, PhD Mila Lagman, MA Joseph Schwartz, PhD Tomohiko Asano, MD Perola Lamba, MD Prabodh K. Sehajpal, PhD Phyllis August, MD, MPH John R. Lee, MD Surya Seshan, MD Daniel Boffa, MD Jun B. Lee, MD Divya Shankaranarayanan, MD Roxana Bologa, MD Baogui Li, PhD Vijay K. Sharma, PhD Christina Chang, BS Carol Li, BS Catherine Snopkowski, BS Elaine Cheng, MD Fu. L. Luan, MD Scott Solomon, MD Darshana M. Dadhania, MD, MS Michelle Lieberman Lubetzky, MD Karsten Suhre, PhD Graciela De Boccardo, MD Xunrong Luo, MD, PhD Ravi R. Tatapudi, MD, DM Iwijn De Vlaminck, PhD Khaled Machaca, PhD Gaurav Thareja, PhD Ruchuang Ding, MD Mary Maluccio, MD Dolca Thomas, MD Olivier Elemento, PhD Marie Matignon, MD Akanksha Verma, PhD Choli Hartono, MD Mara Medeiros, MD Allison Webber, MD Christine Hoang, BS Franco Mueller, MD Guo-Ping Xu, MD Minoru Hojo, MD, PhD Vidya Murthy, MS Hua Yang, MD Dinesh Kannabhiran, MD Thangamani Muthukumar, MD “STANDING ON THE SHOULDERS OF GIANTS” Progress in research is based on contributions from many gifted scientists, and I must apologize for the (provincial) citing of papers from my own laboratory and failing to list the seminal contributions of scientists that contributed substantially to our own success; for example, the invention of the transformational monoclonal antibody technology by Cesar Milstein and Georges Kohler and the breakthrough invention of PCR by Karry Mullis. The abbreviated list citations are following the format of this article, which as a past Editor of the Journal, I would not want to violate or, even worse, “risking” rejection of an invited article! In closing, I would like express again my deep appreciation for the high honor bestowed by the Transplantation Society. It is truly humbling to be included in the constellation of legends previously recognized with the Medawar Prize. Again, it is very special to me to be the corecipient of the Medawar Prize along with the multitalented Jeremy Chapman. The preeminent Carnatic musician, Tyagaraja, from my own country, composed in Telugu the beautiful lyric “Endaro Mahanubhavulu Andariki Vandanamulu” (Wherever there are great souls in this world, my salutations to all of them). The poet’s tribute captures well my respect for the members of the transplantation community striving day in and day out to make our patients’ lives better. Thank you very much, President Cantarovich, Members of Medawar Prize Selection Committee, and Members and Guests of The Transplantation Society.