Molecular cloning, biochemical characterization, and partial protective immunity of the heme-binding glutathione S-transferases from the human hookworm Necator americanus.
Hookworm glutathione S-transferases (GSTs) are critical for parasite blood feeding and survival and represent potential targets for vaccination. Three cDNAs, each encoding a full-length GST protein from the human hookworm Necator americanus (and designated Na-GST-1, Na-GST-2, and Na-GST-3, respectively) were isolated from cDNA based on their sequence similarity to Ac-GST-1, a GST from the dog hookworm Ancylostoma caninum. The open reading frames of the three N. americanus GSTs each contain 206 amino acids with 51% to 69% sequence identity between each other and Ac-GST-1. Sequence alignment with GSTs from other organisms shows that the three Na-GSTs belong to a nematode-specific nu-class GST family. All three Na-GSTs, when expressed in Pichia pastoris, exhibited low lipid peroxidase and glutathione-conjugating enzymatic activities but high heme-binding capacities, and they may be involved in the detoxification and/or transport of heme. In two separate vaccine trials, recombinant Na-GST-1 formulated with Alhydrogel elicited 32 and 39% reductions in adult hookworm burdens (P < 0.05) following N. americanus larval challenge relative to the results for a group immunized with Alhydrogel alone. In contrast, no protection was observed in vaccine trials with Na-GST-2 or Na-GST-3. On the basis of these and other preclinical data, Na-GST-1 is under possible consideration for further vaccine development.
Department of Microbiology and Tropical Medicine, The George Washington University and Sabin Vaccine Institute, Ross Hall 736, 2300 Eye St NW, Washington, DC 20037, USA. mtmbxz@gwumc.edu
Bin
B
Zhan
Samirah
S
Perally
Peter M
PM
Brophy
Jian
J
Xue
Gaddam
G
Goud
Sen
S
Liu
Vehid
V
Deumic
Luciana M
LM
de Oliveira
Jeffrey
J
Bethony
Maria Elena
ME
Bottazzi
Desheng
D
Jiang
Portia
P
Gillespie
Shu-Hua
SH
Xiao
Richi
R
Gupta
Alex
A
Loukas
Najju
N
Ranjit
Sara
S
Lustigman
Yelena
Y
Oksov
Peter
P
Hotez
D000276:Adjuvants, Immunologic / Q000008:administration & dosage; D000536:Aluminum Hydroxide / Q000008:administration & dosage; D000595:Amino Acid Sequence; D000818:Animals; D000947:Antigens, Helminth / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D003001:Cloning, Molecular; D006224:Cricetinae; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D018509:DNA, Helminth / Q000235:genetics / Q000302:isolation & purification; D015870:Gene Expression; D005978:Glutathione / Q000378:metabolism; D005982:Glutathione Transferase / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D006418:Heme / Q000378:metabolism*; D006801:Humans; D015227:Lipid Peroxidation; D008969:Molecular Sequence Data; D017221:Necator americanus / Q000201:enzymology* / Q000235:genetics / Q000276:immunology*; D009332:Necatoriasis / Q000276:immunology / Q000517:prevention & control*; D016366:Open Reading Frames; D010843:Pichia / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D022223:Vaccines, Subunit / Q000276:immunology
D000276:Adjuvants, Immunologic; D000947:Antigens, Helminth; D018076:DNA, Complementary; D018509:DNA, Helminth; D011994:Recombinant Proteins; D022223:Vaccines, Subunit; D006418:Heme; D000536:Aluminum Hydroxide; D005982:Glutathione Transferase; D005978:Glutathione