DETECTION AND TYPING OF HERPES-SIMPLEX VIRUSES BY USING RECOMBINANT IMMUNOGLOBULIN FRAGMENTS PRODUCED IN BACTERIAL

Thirty-seven bacterial clones producing human recombinant monoclonal a ntibody Fab fragments (rFabs) reactive to herpes simplex virus (HSV) a ntigens mere selected from a human combinatorial antibody library cons tructed in a phage-display vector by a panning procedure against an HS V lysate. Thirty-four of the HSV-specific rFabs were able to specifica lly recognize HSV-infected cells in indirect immunofluorescence (IF) a ssays; of these, 25 recognized cells infected by either HSV type 1 (HS V-1) or HSV-2, while 9 recognized only HSV-1-infected cells. One HSV t ype-common rFab (rFab H37) and one HSV-1-specific rFab (rFab H85) were further evaluated as reagents for viral detection and typing by IF st aining in 134 HSV-positive (72 HSV-I and 62 HSV-2) viral cultures from clinical specimens. The results obtained with these two rFabs were fu lly consistent with those obtained with a commercial preparation of fl uorescein-labeled anti-HSV type-specific murine monoclonal antibodies. The detection sensitivity with the type-common rFab in indirect IF as says was higher overall than that provided by the type-specific murine monoclonal antibodies. Preparations of rFabs suitable for IF staining can be easily and inexpensively obtained in a clinical microbiology l aboratory from Escherichia coli cultures. Similar HSV-specific rFabs, therefore, could be advantageous for in vitro diagnostic purposes.