The targeted Itgal (LFA-1) gene encodes the integrin alpha L chain and is involved in leukocyte intercellular adhesion and lymphocyte costimulator signaling. It is essential for cell-mediated cytotoxicity by cytotoxic T- lymphocytes (CTL) and natural killer (NK) cells .
Mice homozygous for the knockout allele are viable and fertile, exhibiting no overt phenotype. Leukocytes from LFA-1 deficient mice fail to aggregate in response to PMA, indicating a failure of homotypic leukocyte adhesion. In addition, T cells exhibit a reduced proliferative capacity in mixed lymphocyte reaction (MLR) assays, NK cytotoxicity is reduced and delayed-type hypersensitivity (DTH) is absent. 
Although mice can mount a normal CTL response to LCMV and VSV infections, they fail to prime or reject injected tumor cells. These mice may be useful for studies of lymphocyte activation and proliferation.

Itgal (LFA-1) knock-out mice exhibit defective leukocyte adhesion, reduced NK cytoxicity, absent DTH, and a selective defect in the induction of peripheral immune responses. These mice may be useful for studies of lymphocyte activation and proliferation.

This strain is hosted by NIH's MMRRC, which partners with JAX for the distribution of this and other strains. For additional information and to purchase, please visit the MMRRC site.