Human immunodeficiency virus type 1 infection, mucosal immunity, and pathogenesis: comments and conference summary.

Infection with human immunodeficiency virus type 1 (HIV1) has now been reported in virtually every country of the world. Responding to the challenge of this devastating pandemic, basic and clinical investigators in many regions of the world have rapidly advanced our understanding of the biology, immunology, and virology of systemic HIV-1 infection. Although the vast majority of HIV-1 infections are acquired through mucosal transmission, information regarding the immunobiology of mucosal HIV-1 infection has been more difficult to obtain due to the difficulties of studying mucosal tissues in vivo and primary mucosal cells in vitro. Many of these difficulties have now been overcome, leading to new insights into the pathogenesis of mucosal HIV-1 infection. To address this emerging and important area of study, this symposium brought together basic and clinical investigators whose work focuses directly or indirectly on mucosal HIV-1 disease. The work discussed by these investigators covered the following seven areas: mucosal transmission, primate models of transmission and disease, mucosal cells and tropism, viral tropism, mucosal defense and HIV-1, pathogenesis of opportunistic mucosal pathogens, and mucosal immunity and vaccination. The salient points of many of these observations are presented individually in the following articles, and highlights of presentations by Sten Vermund, Deborah Anderson, Norman Letvin, Andrew Lackner, Mario Stevenson, Eric Hunter, Jan Orenstein, Rosemary Soave, Kent Sepkowitz, Barney Graham, and Jay Berzofsky are summarized below. Sten Vermund (University of Alabama at Birmingham) emphasized the magnitude of the AIDS epidemic and summarized recent epidemiologic trends. In 1989, the cumulative number of AIDS cases in the United States was 100,000, but by 1997, the number had increased dramatically to 600,000. By 1993, AIDS had become the leading cause of death among persons between 25 and 44 years of age living in the United States. The