| First Author | Nishimura H | Year | 1998 |
| Journal | Int Immunol | Volume | 10 |
| Issue | 10 | Pages | 1563-72 |
| PubMed ID | 9796923 | Mgi Jnum | J:50688 |
| Mgi Id | MGI:1309586 | Doi | 10.1093/intimm/10.10.1563 |
| Citation | Nishimura H, et al. (1998) Immunological studies on PD-1 deficient mice: implication of PD-1 as a negative regulator for B cell responses. Int Immunol 10(10):1563-72 |
| abstractText | PD-1, an Ig superfamily member, contains an immunoreceptor tyrosine-based inhibitory motif in the cytoplasmic tail. It is expressed in a minor fraction of CD4-CD8- normal thymocytes and induced in peripheral lymphocytes following activation. To assess the possible roles of PD-1 in the immune responses, PD-1-deficient (PD-1-/-) mice were generated by a gene-targeting strategy. PD-1-4- mice developed and grew normally. Although the thymus was apparently normal, PD-1-/- mice showed moderate but consistent splenomegaly, which reflected the increased cellularity of both lymphoid and myeloid cells. The proliferative response of B cells by anti-IgM antibodies, but not of T cells by an anti-CD3 (145-2C11) mAb in vitro, was augmented in PD-1-/- mice as compared with control littermates. PD-1-/- mice showed increased serum levels of IgG2b, IgA and most strikingly IgG3, while those of IgM and IgG1 were comparable with control mice. Furthermore, PD-1-/- mice exhibited significantly augmented IgG3 anti-DNP antibody response to a type 2 T-independent antigen, DNP-Ficoll, with comparable IgM and IgG1 antibody responses with littermate controls. In the peritoneal cavity, the B-1 cell population in PD-1-/- mice exhibited significantly reduced expression of CD5, a negative regulator of B-1 cell activation, despite a marginal increase in the number of B-1 cells. Thus, PD-1 was suggested to be involved in the negative regulation for particular aspects of B cell proliferation and differentiation including class switching. |
