Specific antibody responses to vaccination with bivalent CM235/SF2 gp120: detection of homologous and heterologous neutralizing antibody to subtype E (CRF01.AE) HIV type 1.
HIV-1 CRF.AE-01 (formerly subtype E) infection is highly prevalent in Southeast Asia. Despite success with public health measures, the development of an effective CRF01.AE vaccine is critical to the control of this epidemic. Sera from the open-label arms of the first clinical trial of a bivalent HIV gp120 SF2/CM235 (subtypes B and CRF.AE-01, respectively) vaccine were evaluated for the presence of gp120-specific binding (BAb) and neutralizing antibody (NAb). Twelve pre- and postvaccination sera pairs were tested for CM235 BAb; anti-gp120 CM235 BAb was found in all postvaccination samples. The 12 pre- and postvaccination (1 month after third vaccination) serum pairs were evaluated in several neutralization formats: heterologous T cell line adapted (TCLA) NP03/H9, homologous CM235/PBMC, CM235/dendritic cell, and CM235M4-C4.6/A3R5. A3R5 is a CCR5+ T cell line, and CM235M4-C4.6 is the homologous CM235 virus adapted to growth in A3R5 cells. All volunteers developed BAb, but meaningful NAb was not demonstrable against primary isolate CM235. Using the TCLA CRF01.AE virus NP03 in H9 cells, 9 of 12 persons had NAb with a geometric mean titer (GMT) of 46. The CM235M4-C4.6 virus in A3R5 cells also detected NAb in 9 of 12 persons, with a GMT of 41. CM235M4-C4.6/A3R5 detected NAb in two persons with negligible NAb to NP03/H9 and vice versa. Whether the NAb detected by the CM235M4-C4.6/A3R5 system is qualitatively different from those in more traditional NP03/H9 assays will require further study.
Kim
Jerome H
JH
U.S. Military HIV Research Program, Rockville, Maryland 20850, USA. jkim@hivresearch.org
Pitisuttithum
Punnee
P
Kamboonruang
Chirasak
C
Chuenchitra
Thippawan
T
Mascola
John
J
Frankel
Sarah S
SS
DeSouza
Mark S
MS
Polonis
Victoria
V
McLinden
Robert
R
Sambor
Anna
A
Brown
Arthur E
AE
Phonrat
Benjaluck
B
Rungruengthanakit
Kittipong
K
Duliege
Anne-Marie
AM
Robb
Merlin L
ML
McNeil
John
J
Birx
Deborah L
DL
D016915:AIDS Vaccines / Q000276:immunology*; D000595:Amino Acid Sequence; D004311:Double-Blind Method; D015483:HIV Antibodies / Q000097:blood*; D015699:HIV Envelope Protein gp120 / Q000276:immunology*; D015497:HIV-1 / Q000145:classification / Q000276:immunology*; D006801:Humans; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D019713:Receptors, CCR5 / Q000032:analysis; D014611:Vaccination
D016915:AIDS Vaccines; D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; D019713:Receptors, CCR5