Adoptive transfer of infectious bronchitis virus primed alpha beta T cells bearing CD8 antigen protects chicks from acute infection

Infectious bronchitis virus (IBV) infection and associated illness may be dramatically modified by passive transfer of immune T lymphocytes. Lymphocytes collected 10 days postinfection were transferred to naive chicks before challenge with virus. As determined by respiratory illness and viral load, transfer of syngeneic immune T lymphocytes protected chicks from challenge infection, whereas no protection was observed in the chicks receiving the MHC compatible lymphocytes from uninfected chicks. Protection following administration of T lymphocytes could be observed in chicks with three distinct MHC haplotypes: B super(8)/B super(8), B super(12)/B super(12), and B super(19)/B super(19). Nearly complete elimination of viral infection and illness was observed in chicks receiving cells enriched in alpha beta lymphocytes. In contrast, removal of gamma delta T lymphocytes had only a small effect on their potential to protect chicks. The adoptive transfer of enriched CD8 super(+) or CD4 super(+) T lymphocytes indicated that protection was also a function primarily of CD8-bearing cells. These results indicated that alpha beta T lymphocytes bearing CD8 super(+) antigens are critical in protecting chicks from IBV infection.