Mice homozygous for the Cd28tm1Mak targeted mutation exhibit normal development of T and B cells, but have an impaired response to lectins. Other characteristics of homozygous mutant mice include decreased IL2 receptor expression, reduced basal Ig levels, low titers of IgG1 and IgG2b but increased IgG2a, reduced activity of T helper cells and diminished Ig class switching after infection with vesicular stomatitis virus. Infection of mice with lymphocytic choriomeningities virus creates induced and delayed-type hypersensitivity response in cytotoxic T cells.
This strain was developed in the laboratory of Dr. Tak Mak at the Amgen Institute, Ontario Cancer Institute. In these CD28 KO mice, a genomic fragment containing part of exon 2 was replaced by a neomycin resistance cassette.
A 48 SNP (single nucleotide polymorphism) panel analysis, with 43 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the rederived living colony at The Jackson Laboratory Repository. One of the 43 markers, on Chromosome 1, was segregating, perhaps with the gene of interest.
|Allele Name||targeted mutation 1, Tak Mak|
|Allele Type||Targeted (Null/Knockout)|
|Allele Synonym(s)||CD28-; CD28KO|
|Gene Symbol and Name||Cd28, CD28 antigen|
|Strain of Origin||129S2/SvPas|
|Molecular Note||A genomic fragment containing part of exon 2 was replaced by a neomycin resistance cassette. Flow-cytometry analysis on peripheral blood lymphocytes demonstrated that the protein was not expressed in these cells in homozygous mice.|
|Mutations Made By|| |
Dr. Tak Mak, University Health Network/Un of Toronto
When using the CD28- mouse strain in a publication, please cite the originating article(s) and include JAX stock #002666 in your Materials and Methods section.