Development of a cytotoxic T-cell assay in rabbits to evaluate early immune response to human T-lymphotropic virus type 1 infection.
Human T-lymphotropic virus type 1 (HTLV-1) infection causes adult T-cell lymphoma/leukemia (ATL) following a prolonged clinical incubation period, despite a robust adaptive immune response against the virus. Early immune responses that allow establishment of the infection are difficult to study without effective animal models. We have developed a cytotoxic T-lymphocyte (CTL) assay to monitor the early events of HTLV-1 infection in rabbits. Rabbit skin fibroblast cell lines were established by transformation with a plasmid expressing simian virus 40 (SV40) large T antigen and used as autochthonous targets (derived from same individual animal) to measure CTL activity against HTLV-1 infection in rabbits. Recombinant vaccinia virus (rVV) constructs expressing either HTLV-1 envelope surface unit (SU) glycoprotein 46 or Tax proteins were used to infect fibroblast targets in a (51)Cr-release CTL assay. Rabbits inoculated with Jurkat T cells or ACH.2 cells (expressing ACH HTLV-1 molecule clone) were monitored at 0, 2, 4, 6, 8, 13, 21, and 34 wk post-infection. ACH.2-inoculated rabbits were monitored serologically and for viral infected cells following ex vivo culture. Proviral load analysis indicated that rabbits with higher proviral loads had significant CTL activity against HTLV-1 SU as early as 2 wk post-infection, while both low- and high-proviral-load groups had minimal Tax-specific CTL activity throughout the study. This first development of a stringent assay to measure HTLV-1 SU and Tax-specific CTL assay in the rabbit model will enhance immunopathogenesis studies of HTLV-1 infection. Our data suggest that during the early weeks following infection, HTLV-1-specific CTL responses are primarily targeted against Env-SU.
Haynes
Rashade A H
RA
Center for Retrovirus Research and Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210-1093, USA.
Phipps
Andrew J
AJ
Yamamoto
Brenda
B
Green
Patrick
P
Lairmore
Michael D
MD
D000818:Animals; D002461:Cell Line, Transformed; D003601:Cytotoxicity Tests, Immunologic / Q000379:methods*; D005260:Female; D005347:Fibroblasts / Q000821:virology; D015686:Gene Products, env / Q000235:genetics / Q000276:immunology; D016356:Gene Products, tax / Q000276:immunology; D016355:Genes, pX; D015490:HTLV-I Infections / Q000276:immunology*; D015368:Human T-lymphotropic virus 1 / Q000276:immunology* / Q000502:physiology; D006801:Humans; D019169:Jurkat Cells / Q000276:immunology; D008285:Major Histocompatibility Complex / Q000276:immunology; D011533:Proviruses / Q000302:isolation & purification; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000276:immunology; D015682:Retroviridae Proteins, Oncogenic / Q000235:genetics / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D013997:Time Factors; D014779:Virus Replication
D015686:Gene Products, env; D016356:Gene Products, tax; D011993:Recombinant Fusion Proteins; D015682:Retroviridae Proteins, Oncogenic; C055266:gp46 protein, Human T-cell leukemia virus type I; C514970:tax protein, Human T-lymphotrophic virus 1