| First Author | Villegas EN | Year | 1999 |
| Journal | J Immunol | Volume | 163 |
| Issue | 6 | Pages | 3344-53 |
| PubMed ID | 10477604 | Mgi Jnum | J:119602 |
| Mgi Id | MGI:3702831 | Doi | 10.4049/jimmunol.163.6.3344 |
| Citation | Villegas EN, et al. (1999) Role of CD28 in the generation of effector and memory responses required for resistance to Toxoplasma gondii. J Immunol 163(6):3344-53 |
| abstractText | CD28 deficient (CD28-/-) mice were used to study the role of costimulation in the T cell-mediated, IFN-gamma-dependent mechanism of resistance to Toxoplasma gondii. These mice were resistant to infection with the ME49 strain of T. gondii. Analysis of the immune response of acutely infected CD28-/- mice revealed that IL-12 was required for T cell production of IFN-gamma and this was independent of the CD40/CD40 ligand interaction. A similar mechanism of IL-12-dependent, CD28/B7 independent production of IFN-gamma by T cells was also observed in wild-type mice. Interestingly, although chronically infected wild-type mice were resistant to rechallenge with the virulent RH strain of T. gondii, chronically infected CD28-/- mice were susceptible to rechallenge with the RH strain. This deficiency in the protective memory response by CD28-/- mice correlated with a lack of IL-2 and IFN-gamma in recall responses and reduced numbers of CD4+ T cells expressing a memory phenotype. Together, our findings demonstrate that CD28 is not required for the development of a protective T cell response to T. gondii, but CD28 is required for an optimal secondary immune response. |
