TABLE 2.

Vaccines targeting the production of MAb 2F5

Target Ab (reference[s])ImmunogenEpitope supported by membraneAnimalImmunization scheduleaELISA antigenbAb titerc50% Nt titerdStrain(s) tested and assay method
2F5 (161)Chimeric influenza virus with ELDKWA epitope inserted into site B of HANo, virus is enveloped, but B loop is not next to membraneOF-1 miceMice were immunized with chimeric influenza virus or WT control; 102 PFU i.n. (1st), 5 × 105 PFU i.n. (2nd), 20 μg inactivated virus in incomplete Freund's adjuvant (3rd); 21-day intervals between immunizationsGlutathione S-transferase-ELDKWA fusion proteinIgG, medium; high IgA, low40-320MN, RF, and IIIB, by syncytium inhibition
2F5 (140)Chimeric potato virus X with ELDKWA at N terminus of coat proteinNoC57BL/10 miceMice received chimeric virus or WT control without adjuvant; 50 μg i.p. 6 times every 14 days or 50 μg i.n. 11 times every 7 daysQTQQEKNAQELLELDKWASLi.p. IgG, medium; i.n. IgG, medium; medium-high i.n. IgA, low to medium (endpoint titers)∼180-200IIIB, by syncytium inhibition
2F5 (264)Chimeric bovine papillomavirus VLPs expressing ELDKWA in N terminus of L1 proteinNoBALB/c miceMice received chimeric virus or WT control without adjuvant; 10 μg i.m. 2 times at 14-day intervals or 10 μg, orally 2 times at 14-day intervalsELDKWALow1/20 dilution of sera decreased p24 by threefoldMN, Bal, and Ada, by detection of p24 by ELISA
2F5 (121)Chimeric hepatitis A virus in which 2F5 epitope is inserted into domain 2A at C terminus of structural protein VP1NoGuinea pigs and marmosetFor guinea pigs, 1.7 μg of 70S procapsids in complete Freund's adjuvant s.c. and i.m. 3 times at 2-wk intervals; for marmosets, 100 μg of 160S particles 1 time i.o. and i.v.; no adjuvantGGGLELDKWASLWGuinea pigs, low; marmoset, low1/40 serum dilution was testedLAVLAI, by detection of reverse transcriptase activity
2F5 (126)DNA expressing LLELDKWASL inserted into HIV-1 gp140 V1, V2, V3, or V4 loopNoBALB/c mice, guinea pigsAnimal groups were inoculated with DNA expressing the 2F5 epitope in gp120 V1, V2, V3, or V4 loops; 100 μg DNA (mice) and 800 μg DNA (guinea pig) i.m. 2 times at 28-day intervalsELLELDKWASLWN and soluble gp120Anti-2F5 titers, low to medium Anti-gp120 titers, medium to high (mice immunized with V2 insert); anti-2F5 titers, medium to medium-high; anti-gp120 titers, medium-high to high (Guinea pigs immunized with V2 insert)Not NtIIIB, by syncytium inhibition
2F5 (46)ELDKWA inserted at various sites of MBP of E. coliNoBALB/c miceMice were immunized with MBP bearing ELDKWA epitope or WT MBP; 10 μg protein adsorped to alum i.p. 3 times at 21-day intervalsLLELDKWASLFor BALB/c mice immunized with MBP with 4 tandem repeats of 2F5 epitope, low to medium-highNot NtMN, RF, and primary isolate, by syncytium inhibition
2F5 (100)ELDKWAS sequence fused into framework regions of anti-HLA-DR MAbNoNew Zealand White rabbitsRabbits were immunized with anti-HLA DR MAb bearing ELDKWAS sequence at different locations or WT or control Abs; 200 μg protein in complete Freund's adjuvant or saline boosted two more times at 4-wk intervals, first with 200 μg protein and then with 100 μg proteingp160Low to mediumNot NtR2, by single-cycle HIV infectivity assay
2F5 (112)Synthetic peptides containing 2F5 epitope constrained to enhance α-helix structure and conjugated to KLHNoGuinea pigs40 μg conjugate administered 3 times at 4-wk intervals with QS21 adjuvantSynthetic peptides containing 2F5 epitope and constrained in α-helixHigh to very highNot NtHXB2, by single-cycle HIV infectivity assay
2F5 (145, 146)Cyclic β-turn peptides containing ELLELDKWASLW conjugated to KLH or outer membrane protein of N. meningitidisNoGuinea pigs40 μg conjugate administered 3 times at 4-wk intervals with QS21 adjuvantELLELDKWASLW, disordered and constrained into β-turnVery highNot NtHXB2, by single-cycle HIV infectivity assay
2F5 (57)DNA expressing gp160 and CCR5 and peptides with variations on the ELDKWAS sequence, gp41 coil peptide (QLQARVL), and CCR5 second-loop peptideDNA, yes; peptide, noC57BL/6 micePrime i.n. with 25 μg gp160/CCR5 DNA and boost with 10-μg mix of ELDKWAS, gp41 coil, and CCR5 second-loop peptides 8 wk after prime (group 1); 2 i.n. immunizations with 10-μg mix of ELDKWAS, gp41 coil, and CCR5 second loop (group 2); 2 i.n. immunizations of PBSELDKWAS, coiled-coil peptide, V3 loop peptide, CCR5 second-loop peptide, gp160Group1 and 2 anti-ELDKWAS IgG, medium; groups 1 and 2 anti-coiled-coil peptide, V3 loop peptide, CCR5 second-loop peptide, and gp160 IgG, low; group 5, no Ab response detected; all IgA responses were lowGroup 1, ∼100-240; groups 2 and 3 did not reach 50% neutralization at serum dilutions of 1/20SF2 and primary isolate, by p24 production
  • a Immunization routes are abbreviated as follows: intranasal, i.n.; intraperitoneal, i.p.; subcutaneous, s.c.; intramuscular, i.m.; intraosseous, i.o.; intravenous, i.v.

  • b Amino acid sequences describe synthetic peptides used to determine Ab titers.

  • c Titers are described as follows: low, <1,000; medium, 1,000 to 15,000; medium-high, 15,000 to 50,000; high, 50,000 to 1,000,000; very high, >1,000,000. The difference between endpoint and midpoint titers was not taken into account.

  • d Strains that were neutralized are in boldface type.