Lectins as Promising Therapeutics for the Prevention and Treatment of HIV and Other Potential Coinfections

Mazalovska, Milena; Kouokam, J. Calvin

Tuberculosis (TB) caused by the bacterium Mycobacterium tuberculosis is one of the top 10 causes of mortality worldwide according to the WHO [108] . In addition to killing over one million people yearly, TB is also the leading cause of death among HIV positive individuals [108] . Although TB is treatable, the prevalence of a multiresistant form of TB (MDR-TB) that does not respond to first-line anti-TB drugs calls for the development of new ways to cope with this infection. In M. tuberculosis, envelope mannosylated lipoarabinomannans (ManLAMs) and Mtb surface glycoproteins (glycosylated 45-kDa [Apa: alanine-and proline-rich antigenic] and 19-kDa proteins) are considered important antigenic molecules with essential roles in host protection against this pathogen; these antigens may be recognized by dendritic cell-specific intercellular adhesion molecule-3 grabbing nonintegrin (DC-SIGN) and other mannosespecific C-type lectins (C-TLs) [109] . Since M. tuberculosis organisms have large amounts of mannosylated cell-surface molecules, an attempt was made to assess whether lectins with potent anti-HIV activity can also inhibit these bacteria. It was reported that CV-N competes with C-type lectins DC-SIGN and mannose receptor for binding to ManLAMs and inhibits the binding of bacteria to dendritic cells. However, in vivo findings showed that this binding did not inhibit or delay infection. The authors speculated that such observation could be due to the fact that murine C-type lectins differ from human versions, which requires further investigation [110] .