| First Author | Wong SC | Year | 2003 |
| Journal | Blood | Volume | 102 |
| Issue | 4 | Pages | 1381-8 |
| PubMed ID | 12714510 | Mgi Jnum | J:84893 |
| Mgi Id | MGI:2670548 | Doi | 10.1182/blood-2002-08-2416 |
| Citation | Wong SC, et al. (2003) Impaired germinal center formation and recall T-cell-dependent immune responses in mice lacking the costimulatory ligand B7-H2. Blood 102(4):1381-8 |
| abstractText | B7-H2, which is expressed constitutively on B cells and binds the inducible costimulator (ICOS) on antigen-activated T cells, is a member of the B7 family of costimulatory ligands. We have inactivated B7-H2 in the mouse. B7-H2-/- mice generate normal populations of B and T cells in their various lymphoid organs but have lower basal levels of heavy chain class-switched antibodies in their sera. These mice are able to mount normal immune responses to both type I and type II T-cell-independent antigens. However, their pattern of responses to a T-cell-dependent antigen is altered, with greatly reduced production of antigen-specific heavy chain class-switched antibodies, the levels of which could not be elevated even with repeated immunizations. This suggests a critical role for B7-H2 in the recall phases of the immune response. Germinal center formation is also impaired in the mutant mice. While B cells from the mutant mice could response normally to anti-IgM, anti-CD40, and lipopolysaccharide stimulation, the production of T-helper-type II cytokines such as interleukin-4 (IL-4) and IL-10 by primed CD4+ T cells from mutant mice were reduced. This indicated that the defects in humoral responses and germinal center formation in B7-H2-deficient mice are due to the lack of T-cell-mediated help to the B cells. Hence, B7-H2 on B cells is important for recruiting T-cell help via its interaction with ICOS and plays a critical role in costimulating humoral immune responses. |
