       Document 0589
 DOCN  M9630589
 TI    Studies of complement-activating antibodies in the SIV/macaque model of
       acute primary infection and vaccine protection.
 DT    9603
 AU    Montefiori DC; Reimann KA; Letvin NL; Zhou J; Hu SL; Department of
       Surgery, Duke University Medical Center, Durham,; North Carolina 27710,
       USA.
 SO    AIDS Res Hum Retroviruses. 1995 Aug;11(8):963-70. Unique Identifier :
       AIDSLINE MED/96020097
 AB    Questions regarding the potential impact of complement-activating
       antibodies on lentivirus pathogenesis and vaccine development were
       addressed in the SIV/macaque model by evaluating sera for activity
       related to complement-mediated, antibody-dependent enhancement (C'-ADE)
       of SIV infection in vitro. C'-ADE activity in sera obtained during acute
       primary infection in macaques inoculated with SIVmac251 appeared before
       neutralizing antibodies and coincided with the initial peak and decline
       of plasma antigenemia. The power of C'-ADE activity (i.e., virus
       production measured by p24 immunoassay) decreased as titers of
       neutralizing antibodies increased in these animals, suggesting a balance
       in the net effect between C'-ADE and neutralizing activities in vitro.
       Antibodies with C'-ADE activity were also induced in macaques immunized
       with live-attenuated SIVmac239/nef-deletion or primed with recombinant
       SIVmne gp120 vaccinia virus and boosted with SIVmne rgp160. The titer
       (i.e., last serum dilution to show enhancement), peak (i.e., serum
       dilution producing the greatest enhancement as measured by p24
       production), and power (i.e., magnitude of p24 production at the peak
       titer) of C'-ADE activity in sera obtained from vaccinated macaques on
       the day of challenge were comparable to those of sera from infected
       macaques and showed no correlation with vaccine outcome, where some
       protected animals had C'-ADE profiles that resembled those of
       unprotected animals. The results of these studies suggest that
       antibodies having C'-ADE activity in vitro could contribute to virus
       replication or, alternatively, to virus clearance during the acute stage
       of SIV infection in macaques.(ABSTRACT TRUNCATED AT 250 WORDS)
 DE    Animal  Antibodies, Viral/*IMMUNOLOGY  Complement Activation/*IMMUNOLOGY
       Macaca  Recombinant Proteins/GENETICS/IMMUNOLOGY  Simian Acquired
       Immunodeficiency Syndrome/*IMMUNOLOGY/PREVENTION  & CONTROL  Support,
       U.S. Gov't, P.H.S.  SIV/*IMMUNOLOGY  Vaccination  Viral Envelope
       Proteins/GENETICS/IMMUNOLOGY  Viral Vaccines/ADMINISTRATION &
       DOSAGE/IMMUNOLOGY  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

