INTRODUCTION AND THE EARLY DAYS

Professor Thomas Lehner is one of the most distin-guished oral and dental researchers to have come out of the UK. Over the past 40 years, he has made an astonishing number of discoveries which have had an impact on our understanding of the patho-genesis of a variety of mucosal diseases. He has consistently practiced both basic and clinical research and built an integrated group of clinical and non-clinical researchers, which allowed him easy transition from the laboratory to the clinic. Tom Lehner was among the early scientists study-ing mucosal immunology, initially exploring oral diseases, with special emphasis on the immunobi-ology of Streptococcus mutans, leading to active and passive vaccination against dental caries. He was the first to demonstrate cellular immunity as the immunopathological basis of periodontal dis-eases, recurrent aphthous stomatitis, and candidia-sis. Over the past 20 years, his expertise in mucosal immunobiology has been applied to the immunol-ogy of HIV/SIV infections. His seminal contribu-tions include regional innate mucosal immunity, prevention of SIV infection in macaques by secre-tory IgA antibodies, up-regulation of CC chemo-kines, and the first demonstration of protective CCR5 antibodies. Arguably, his leadership, his students, and the establishment of immunology applied to oral mucosal diseases will be his great-est legacy. His contributions continue unabated