Vaccine-elicited CD4 T cells induce immunopathology after chronic LCMV infection
Penaloza-MacMaster P., Barber DL., Wherry EJ., Provine NM., Teigler JE., Parenteau L., Blackmore S., Borducchi EN., Larocca RA., Yates KB., Shen H., Haining WN., Sommerstein R., Pinschewer DD., Ahmed R., Barouch DH.
For vaccines, CD4 + T cells can spell trouble The ideal vaccine elicits immune memory—either antibodies or memory T cells—to protect the host from subsequent infections. T cell–mediated immunity requires both helper CD4 + T cells and cytotoxic CD8 + T cells to kill virus-infected cells. But what happens when a vaccine only elicits CD4 + memory T cells? Penaloza-MacMaster et al. probed this question by giving mice a vaccine that generated only memory CD4 + T cells against lymphocytic choriomeningitis virus (LCMV). Instead of protecting mice against chronic LCMV, vaccinated mice developed massive inflammation and died. Virus-specific CD8 + T cells or antibodies protected mice from the pathology. These results may have implications for vaccines against chronic viruses such as HIV. Science , this issue p. 278