Details

Autor(en) / Beteiligte

• Villegas, Eric N
• Elloso, M. Merle
• Reichmann, Gaby
• Peach, Robert
• Hunter, Christopher A

Titel

Role of CD28 in the Generation of Effector and Memory Responses Required for Resistance to Toxoplasma gondii

Ist Teil von

• The Journal of immunology (1950), 1999-09, Vol.163 (6), p.3344-3353

Ort / Verlag

United States: Am Assoc Immnol

Erscheinungsjahr

1999

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• 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.