Document 0313
 DOCN  M9590313
 TI    The CD4 of lymphoblastoid MT-2 cells appears in both monomeric and
       complex configurations.
 DT    9509
 AU    Lynch GW; Sloane A; Dearden M; Humphrey-Smith I; Cunningham A; Dept. of
       Virology, University of Sydney, Westmead Hospital, NSW,; Australia.
 SO    Annu Conf Australas Soc HIV Med. 1994 Nov 3-6;6:190 (unnumbered
       abstract). Unique Identifier : AIDSLINE ASHM6/95291786
 AB    CD4 receptor is an essential molecule in the cellular recognition of
       foreign antigen presentation to T lymphocytes. CD4 also is the principal
       cellular receptor for the binding and infection of HIV to monocytes,
       macrophages and CD4+ lymphocytes. Transmembranous CD4 has up till the
       present been generally viewed as monomorphic with a MW of 55 KDa.
       However, we have observed a variable fraction (approximately 10%-50%) of
       the CD4 protein of lymphoid (MT2) cells as a covalent crosslinked
       complex. The complex was detected by immunoblotting both whole cell
       lysates and anti-CD4 monoclonal antibody immunoprecipitates (i.e., OKT4,
       OKT4A, T4 or leu3a). Interestingly, a varied amount of the higher MW
       species was obtained depending on whether the precipitations were
       performed using OKT4 or leu 3a Mabs (OKT4 > leu 3a). Immunoprecipitation
       with OKT4 yielded up to approximately 50% of the antibody reactive CD4
       appearing in a complex. To complement these observations, earlier
       studies (Layne, et al Nature 346: 277(1990), Earl, et al PNAS:
       87:648(1990)) have described the oligomerization of HIV gp120. Clearly
       the configuration of CD4 within the membrane of cells is pivotal to the
       immune response and the pathogenesis of HIV. Multimeric association of
       Ags with cell surface CD4 complex is likely to facilitate high affinity
       antigen presenting cell interactions. In the pathological state,
       multimers of gp120 binding to CD4 complex may be recruited for
       successful virus-cell membrane fusion leading to HIV internalisation.
 DE    Antigens, CD4/*IMMUNOLOGY  Cell Line  Human  HIV/*IMMUNOLOGY  HIV
       Envelope Protein gp120/IMMUNOLOGY  Receptors, HIV/*IMMUNOLOGY
       T-Lymphocytes/*IMMUNOLOGY  Viral Fusion Proteins/*IMMUNOLOGY  Virus
       Integration/IMMUNOLOGY  MEETING ABSTRACT

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