TI   "A Slippery Defence Against HIV"
 AU   Thompson, Clare
 SO   Lancet (12/18/93-12/25/93) Vol. 342, No. 8886/8887, P. 1500
 AB   Mucosal-associated lymphoid tissue accounts for the largest area   of
      immunologically active tissue in the body, the busiest of which is
      mucosa of the gastrointestinal tract, which is perpetually dealing
      with pathogens picked up in food.  Ways of using this area for host
      defense have not been extensively explored, but the possibilities for
      immunotherapy against diseases of the mucosal surface are
      significant.  One of the most exciting new applications is a possible
      vaccine for HIV.  Lehner et al. theorize that stimulation of
      secretory IgA in the body areas most at risk for HIV transmission,
      such as the vaginal, rectal, and genitourinary mucosa, will prevent
      the virus from crossing the epithelium and entering the
      immunologically active area below.  The researchers also hope for a
      general action on mucosal-associated lymphoid tissue.  If their
      theory is correct, IgA antibodies directed at the gut could produce
      secretory IgA antibodies in the respiratory, salivary, and genital
      areas, as well as other mucosal sites.  While they sound promising,
      one must view these theories with caution.  The strategy depends
      heavily on at least one crucial factor: if the vaginal, rectal, or
      genital epithelium is torn in any way, increased secretory IgA will
      be fruitless.  If the primed T and B cells in the epithelium act as a
      second line of defense, however, the future of mucosal vaccination is
      even more promising.

      Copyright (c) 1993 - Information, Inc., Bethesda, MD.  This
      information is provided by the Centers for Disease Control &
      Prevention (CDC), National AIDS Clearinghouse as a public service. 
      Non-profit reproduction is encouraged.

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