Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2007 May 29;104(22):9422-7.
doi: 10.1073/pnas.0703498104. Epub 2007 May 15.

Monoclonal antibody-mediated enhancement of dengue virus infection in vitro and in vivo and strategies for prevention

Ana P Goncalvez  1 , Ronald E Engle, Marisa St Claire, Robert H Purcell, Ching-Juh Lai
Affiliations

Monoclonal antibody-mediated enhancement of dengue virus infection in vitro and in vivo and strategies for prevention

Ana P Goncalvez et al. Proc Natl Acad Sci U S A. .

Abstract

Infection with dengue virus (DENV) or any other flavivirus induces cross-reactive, but weakly neutralizing or nonneutralizing, antibodies that recognize epitopes involving the fusion peptide in the envelope glycoprotein. Humanized mAb IgG 1A5, derived from a chimpanzee, shares properties of cross-reactive antibodies. mAb IgG 1A5 up-regulated DENV infection by a mechanism of antibody-dependent enhancement (ADE) in a variety of Fc receptor-bearing cells in vitro. A 10- to 1,000-fold increase of viral yield in K562 cells, dependent on the DENV serotype, was observed over a range of subneutralizing concentrations of IgG 1A5. A significant increase of DENV-4 viremia titers (up to 100-fold) was also demonstrated in juvenile rhesus monkeys immunized with passively transferred dilutions of IgG 1A5. These results, together with earlier findings of ADE of DENV-2 infection by a polyclonal serum, establish the primate model for analysis of ADE. Considering the abundance of these cross-reactive antibodies, our observations confirm that significant viral amplification could occur during DENV infections in humans with prior infection or with maternally transferred immunity, possibly leading to severe dengue. Strategies to eliminate ADE were explored by altering the antibody Fc structures responsible for binding to Fc receptors. IgG 1A5 variants, containing amino acid substitutions from the Fc region of IgG2 or IgG4 antibodies, reduced but did not eliminate DENV-4-enhancing activity in K562 cells. Importantly, a 9-aa deletion at the N terminus of the CH(2) domain in the Fc region abrogated the enhancing activity.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Fig. 1.
Fig. 1.
ADE of DENV replication in K562 cells mediated by various concentrations of IgG 1A5. (A) Increase of the viral yields (FFU/ml) of each DENV serotype. The baseline viral yield (dashed line) was ≈1,000 FFU/ml with a DENV sero-negative human IgG1 as control. (B) The percent of cells infected with DENV detected by flow cytometry. (C) The percent of cells infected with 1 MOI of DENV-4 or antigenic variant detected by flow cytometry. Variant DENV-4 v1 contains substitution Leu107Phe and variant DENV-4 v2 contains substitution Gly106Val in E.
Fig. 2.
Fig. 2.
ADE of DENV-4 infection in other Fc receptor-bearing cells mediated by IgG 1A5. (A) ADE in U937 and Raji-1 cells infected with 1 MOI, detected by flow cytometry. (B) ADE in dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN)-expressing Raji-1 cells, detected by flow cytometry. (C) ADE in monkey primary monocytes, detected by flow cytometry. (D) Same as in C but detected by the viral yield.
Fig. 3.
Fig. 3.
ADE of DENV-4 infection in juvenile rhesus monkeys passively administered with IgG 1A5. (A) Viremia titer in monkeys, detected by quantitative PCR. The results are expressed in genome equivalent (GE) and equivalent (Eq) FFU per milliliter. The viremia titers on days 3–6 (indicated by asterisks) for the monkey groups receiving 6, 2.0, 0.67, and 0.22 mg/kg IgG 1A5 were significantly different from that of the control group that received PBS. (B) Same as in A, except that the viremia titer was determined by a direct FFU assay. The variation bars indicate the titer differences (standard error) among monkeys in each group.
Fig. 4.
Fig. 4.
Sequence alterations and generation of a 9-aa deletion in the Fc region. (A) IgG 1A5 variants containing sequence alterations in the Fc that affect Fc receptor binding. The regions at positions 233–236 and at positions 327–331 are known to contribute to Fc receptor binding. The N terminus of CH2 is located at position 231 according to the numbering system used. The substitution sequences in ΔA, ΔB, and ΔC and the deletion sequence (represented by dots in ΔD) of the IgG 1A5 constructs are shown. (B) Altered splicing of mRNA to generate a 9-aa deletion in the Fc of IgG 5H2 ΔD. The illustration depicts a probable mechanism by which substitution of A1058G in IgG 5H2 ΔD renders the normal acceptor splice site at 1059 defective. Alternate splicing occurs at nucleotide position 1086 to generate the 9-aa deletion. C is the confidence value based on the sequence (underlined) for splicing to take place according to the NetGene 2 program (18).
Fig. 5.
Fig. 5.
ADE of DENV-4 infection at 1 MOI in K562 cells mediated by IgG 1A5 Fc variants. (A) IgG 1A5 variants containing sequence substitutions of subclass IgG2 or IgG4 in the Fc. (B) ADE activity of IgG 1A5 abrogated by the 9-aa deletion (ΔD) in the Fc region originally identified in IgG 5H2 ΔD. Dengue-negative human serum was used as control.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Monath TP. Proc Natl Acad Sci USA. 1994;91:2395–2400. - PMC - PubMed
    1. Sabin AB. Am J Trop Med Hyg. 1952;1:30–50. - PubMed
    1. Halstead SB. Yale J Biol Med. 1970;42:350–362. - PMC - PubMed
    1. Kliks SC, Nimmanitya S, Nisalak A, Burke DS. Am J Trop Med Hyg. 1988;38:411–419. - PubMed
    1. Littaua R, Kurane I, Ennis FA. J Immunol. 1990;144:3183–3186. - PubMed

Publication types

MeSH terms