Development of a cytotoxic T-cell assay in rabbits to evaluate early immune response to human T-lymphotropic virus type 1 infection.

Abstract

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.

• Authors: Rashade A H Haynes 2nd, Andrew J Phipps, Brenda Yamamoto, Patrick Green, Michael D Lairmore
• Journal: Viral immunology (Viral Immunol) Vol. 22 Issue 6 Pg. 397-405 (Dec 2009) ISSN: 1557-8976 [Electronic] United States
• PMID: 19951176 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• Gene Products, env
• Gene Products, tax
• Recombinant Fusion Proteins
• Retroviridae Proteins, Oncogenic
• gp46 protein, Human T-cell leukemia virus type I
• tax protein, Human T-lymphotrophic virus 1

Topics

• Animals
• Cell Line, Transformed
• Cytotoxicity Tests, Immunologic (methods)
• Female
• Fibroblasts (virology)
• Gene Products, env (genetics, immunology)
• Gene Products, tax (immunology)
• Genes, pX
• HTLV-I Infections (immunology)
• Human T-lymphotropic virus 1 (immunology, physiology)
• Humans
• Jurkat Cells (immunology)
• Major Histocompatibility Complex (immunology)
• Proviruses (isolation & purification)
• Rabbits
• Recombinant Fusion Proteins (immunology)
• Retroviridae Proteins, Oncogenic (genetics, immunology)
• T-Lymphocytes, Cytotoxic (immunology)
• Time Factors
• Virus Replication