ENV-specific cytotoxic T lymphocyte responses in HIV seronegative health care workers occupationally exposed to HIV-contaminated body fluids.
Identification of the components of protective immunity are crucial for the development of effective prophylactic and therapeutic vaccine strategies. Analysis of HIV-specific responses in exposed but uninfected individuals might thus provide a unique resource to elucidate the components and correlates of protective immunity to HIV. In the present study we analyzed HIV-specific cytotoxic and helper T lymphocyte responses in health care workers (HCW) exposed to body fluids from HIV-positive individuals. HCW exposed to blood from HIV-negative individuals as well as healthy donors served as controls. Cytotoxic T lymphocyte (CTL) responses to HIV envelope (env) peptides were detected in 7/20 (35%) HCW exposed to HIV-positive blood and in none of the 20 health care workers exposed to uninfected blood or the seven healthy blood donors studied. HIV-specific CTL responses were detected only after in vitro stimulation, and were MHC class I restricted. No MHC class I restriction elements were uniformly identified among the different responders. 21/28 (75%) HCW exposed to contaminated blood responded to env as measured by IL-2 production to the peptides, in contrast to only 9/38 (24%) HCW exposed to HIV seronegative blood and 3/35 (9%) healthy blood donors. All the HIV exposed individuals were seronegative on repeated ELISA tests, and no evidence of infection was obtained by PCR analysis. These findings indicate that a single exposure to HIV can induce CTL immunity to HIV antigens, in the absence of other evidence of infection.
Pinto
L A
LA
Experimental Immunology Branche, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
Sullivan
J
J
Berzofsky
J A
JA
Clerici
M
M
Kessler
H A
HA
Landay
A L
AL
Shearer
G M
GM
D000062:Accidents, Occupational; D000328:Adult; D000595:Amino Acid Sequence; D001782:Blood Donors; D001826:Body Fluids / Q000821:virology; D005260:Female; D005500:Follow-Up Studies; D015686:Gene Products, env / Q000276:immunology*; D015658:HIV Infections / Q000517:prevention & control / Q000635:transmission; D018023:HIV Seronegativity / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology* / Q000302:isolation & purification; D006282:Health Personnel; D006801:Humans; D008297:Male; D008506:Medical Waste; D008969:Molecular Sequence Data; D016602:Needlestick Injuries / Q000188:drug therapy / Q000276:immunology; D016273:Occupational Exposure; D011446:Prospective Studies; D011533:Proviruses / Q000302:isolation & purification; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D015215:Zidovudine / Q000627:therapeutic use
D015686:Gene Products, env; D008506:Medical Waste; D015215:Zidovudine