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. 1998 Jan;72(1):286-93.
doi: 10.1128/JVI.72.1.286-293.1998.

Antibody-dependent cellular cytotoxicity directed against cells expressing human immunodeficiency virus type 1 envelope of primary or laboratory-adapted strains by human and chimpanzee monoclonal antibodies of different epitope specificities

O Alsmadi  1 , S A Tilley
Affiliations

Antibody-dependent cellular cytotoxicity directed against cells expressing human immunodeficiency virus type 1 envelope of primary or laboratory-adapted strains by human and chimpanzee monoclonal antibodies of different epitope specificities

O Alsmadi et al. J Virol. 1998 Jan.

Abstract

The characteristics of antibody-dependent cellular cytotoxicity (ADCC) directed by a panel of human and chimpanzee antienvelope (anti-Env) monoclonal antibodies (MAbs) of different epitope specificities were studied; this was accomplished by using target cells expressing human immunodeficiency virus type 1 (HIV-1) Envs of either primary or laboratory-adapted strains. Human MAbs of similar apparent affinities (1 x 10(9) to 2 x 10(9) liters/mol) against either a "cluster II"-overlapping epitope of gp41 or against the CD4 binding site, V3 loop, or C5 domain of gp120 directed substantial and comparable levels of specific lysis against targets infected with laboratory-adapted strains of HIV-1. As expected, those MAbs specific for relatively conserved regions of Env generally exhibited ADCC activity against a broader range of HIV-1 strains than those directed against variable epitopes. Significant ADCC activities of selected MAbs against primary isolate Env-expressing cells were demonstrated. In addition, a new ADCC epitope in the V2 domain of gp120 was defined. CD56+ cells were demonstrated to be the effector cells in these studies by fluorescence-activated cell sorting followed by ADCC assays. Notably, all anti-Env MAbs tested in this study, including MAbs directed against each of the known neutralization epitope clusters in gp120, directed significant levels of ADCC against targets expressing Env of one or more HIV-1 strains. These results imply that many, if not most, HIV-1-neutralizing human Abs of high affinity (> or = 3 x 10(8) liters/mol in these studies) and of the immunoglobulin G1 (IgG1) subclass (i.e., the predominate IgG subclass) are capable of directing ADCC. Since neutralizing Abs have been associated with long-term survival following HIV-1 infection, this suggests that ADCC activity may be beneficial in vivo.

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Figures

FIG. 1
FIG. 1
Results of flow cytometry analyses of uninfected or HIV-1-infected CEM.NKR cells. MAbs 1125H, C108G, and C311E were used at 20 μg/ml. In this experiment, gate 2 was set to exclude ≥99% of the background fluorescence observed with no first Ab added (only fluorescein isothiocyanate conjugate was added) for each type of infected or uninfected cells. The percentage of cells staining within gate 2 (above background) is shown in each panel.
FIG. 2
FIG. 2
Representative ADCC assay results obtained with a panel of human anti-Env MAbs. CEM.NKR cells were chronically infected with the HIV-1 strains indicated. The left side of each panel shows results with the following controls: pooled seropositive serum at 10−3 dilution, irrelevant human (Hu) IgG1 (myeloma protein; ICN Immunobiological, Costa Mesa, Calif.) at 20 μg/ml, and rabbit antiserum against β2 microglobulin (Accurate Chemical, Westbury, N.Y.), a positive control against both uninfected and infected cells, at 33 μg/ml. Results with the latter control against uninfected cells were comparable to those seen against the four infected cell lines shown, while no specific lysis above background was seen against uninfected cells for any of the other Abs and MAbs in this experiment (data not shown). The right side of each panel shows results with various concentrations of each human MAb. The error bars represent standard deviations of duplicate points.
FIG. 3
FIG. 3
ADCC assay results obtained by using Na251CrO4-labeled SF2-infected targets in the presence of various numbers of cold-target cells. Various numbers of unlabeled cells were preincubated with 26 μg of 4117C MAb per ml, while the standard number of labeled targets (104 cells) was separately preincubated with the same amount of 4117C MAb. Following this preincubation, the labeled target-MAb mixture was added to the unlabeled target-MAb (cold-target) mixture, attaining the cold-target cell-per-milliliter concentrations shown in the figure. The remainder of the ADCC assay was carried out as previously described (1). The error bars represent standard deviations of duplicate points.
FIG. 4
FIG. 4
ADCC assay results obtained by using two chimpanzee anti-Env MAbs. CEM.NKR cells were chronically infected with the HIV-1 strains indicated. The left side of each panel shows results with the following controls: pooled seropositive serum at 10−3 dilution and human MAbs 5145A and 41148D, each at 20 μg/ml. The right side of each panel shows results with various concentrations of each chimpanzee MAb. No specific lysis above background was seen against uninfected cells with any of the Abs or MAbs in this experiment (data not shown). The error bars represent standard deviations of triplicate points.
FIG. 5
FIG. 5
Results of ADCC assays using as targets A2.01 cells that were uninfected (A), infected with wild-type vaccinia virus (WR) (B), infected with vPE16, a vaccinia virus recombinant expressing Env of laboratory-adapted strain BH8 (C), or infected with vCB53, a vaccinia virus recombinant expressing a clade E primary isolate Env (D). The left side of each panel shows results with the following controls: irrelevant human (Hu) IgG1 (myeloma protein; ICN Immunobiological) at 40 μg/ml; rabbit antiserum against β2 microglobulin (Accurate Chemical), a positive control against both uninfected and infected cells, at 30 μg/ml; serum from a healthy individual recently immunized against vaccinia virus (anti-vaccinia serum) at 1/200; and HIVIG at 40 μg/ml. The right side of each panel shows results for two or more concentrations of each human or chimpanzee MAb tested. The error bars represent standard deviations of triplicate points.
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References

    1. Alsmadi O, Herz R, Murphy E, Pinter A, Tilley S A. A novel antibody-dependent cellular cytotoxicity epitope in gp120 is identified by two monoclonal antibodies isolated from a long-term survivor of human immunodeficiency virus type 1 infection. J Virol. 1997;71:925–933. - PMC - PubMed
    1. Alsmadi, O., and S. A. Tilley. Unpublished data.
    1. Burton D R, Pyati J, Koduri R, Sharp S J, Thornton G B, Parren P W H I, Sawyer L S W, Hendry R M, Dunlop N, Nara P L, Lamacchia M, Garratty E, Stiehm E R, Bryson Y J, Cao Y, Moore J P, Ho D D, Barbas C F., III Efficient neutralization of primary isolates of HIV-1 by a recombinant human monoclonal antibody. Science. 1994;266:1024–1027. - PubMed
    1. Cao Y, Qin L, Zhang L, Safrit J, Ho D D. Virologic and immunologic characterization of long-term survivors of human immunodeficiency virus type 1 infection. New Engl J Med. 1995;332:201–208. - PubMed
    1. Earl P A, Broder C C, Long D, Lee S A, Peterson J, Chakrabarti S, Doms R W, Moss B. Native oligomeric human immunodeficiency virus type 1 envelope glycoprotein elicits diverse monoclonal antibody reactivities. J Virol. 1994;68:3015–3026. - PMC - PubMed

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