Serological differences between XXXX ) and HTLV-III/LAV.

@entity1 @entity1619 @entity447 @entity791 @entity2662
Sera from each of five preselected groups of @entity1 with @entity791 ( @entity791 ), @entity791 ( @entity791 ), @entity447 , @entity1619 ( @entity1619 ), and healthy controls were examined for antibodies to @entity1 @entity1619 (T-lymphotropic) virus type-I ( @entity2662 ) and HTLV-III by indirect immunofluorescence (IF) and radioimmunoprecipitation (RIP) methods. All sera from five @entity1 with @entity791 , @entity791 , and @entity447 reacted at titers from 1 : 512 to 1 : 5,120 with fixed H9/HTLV-III cells by IF but not with fixed @entity1 cells carrying @entity2662 . Similarly, sera from @entity1 with @entity791 , @entity791 , and @entity447 precipitated HTLV-III-specific polypeptides of 120K, 46K, and 24K. In contrast, sera from five @entity1 with @entity1619 did not react with fixed H9/HTLV-III cells, but reacted with fixed @entity1 cells. Moreover, @entity2662 -specific polypeptides of 68K, 28K, and 24K were precipitated with sera from @entity1619 - @entity1 but not with anti-HTLV-III-positive sera. Recently, we infected @entity2662 -carrying MT-4 cells with HTLV-III and provoked strong cytopathic effects. This system enabled testing for neutralizing antibodies to HTLV-III. Neutralizing titers to HTLV-III of five anti-HTLV-III-positive sera ranged from 1 : 720 to 1 : 9,000. In contrast, all five seronegative controls showed no or only low reactivity to HTLV-III envelope (1 : 80 and 100). However, three out of five anti-HTLV-I-positive sera exhibited weak cross-reactivities with HTLV-III. The reactivities were expressed as less than 1 : 160, except for one case (1 : 720). They were considered to be nonspecific since they were negative for HTLV-III antibodies in the radioimmunoprecipitation studies.
