Novel mouse mutants with primary cellular immunodeficiencies generated by genome-wide mutagenesis.
BACKGROUND
Primary cellular immunodeficiencies are a group of genetic disorders in which 1 or more components of the cellular immune system are lacking or dysfunctional.


OBJECTIVE
We sought to identify novel mouse mutants that display primary cellular immunodeficiencies.


METHODS
Genome-wide N-ethyl-N-nitrosourea mutagenesis was performed in mice, followed by a phenotype screen of immunologic blood parameters.


RESULTS
We identified novel mouse mutants with isolated B-cell deficiency, combined block in early B- and T-cell development, combined T-cell and natural killer cell reduction, and 3 different forms of T-cell deficiencies. One of the mutants, designated DeltaT3, displayed a combined phenotype of increased IgE, absence of peripheral T cells, and block in late thymocyte differentiation. In addition, DeltaT3 mice were unable to mount specific humoral immune responses. Chromosomal mapping and sequencing of candidate genes revealed a novel point mutation in the kinase domain of the T-cell receptor zeta chain-associated protein kinase (Zap70). In contrast to Zap70-deficient mice, DeltaT3 mutants displayed normal Zap70 mRNA and residual Zap70 protein levels. Complementation studies with Zap70-deficient mice confirmed that the point mutation found in Zap70 was causative for the DeltaT3 phenotype, including increased IgE plasma levels, a phenotype that has not been associated with altered Zap70 function in the past.


CONCLUSIONS
Random genome-wide mutagenesis combined with a phenotype screen can be used to generate novel mouse mutants with primary cellular immunodeficiencies.
Jakob
Thilo
T
Allergy Research Group, Department of Dermatology, University Medical Center Freiburg, Freiburg, Germany. thilo.jakob@uniklinik-freiburg.de
Köllisch
Gabriele V
GV
Howaldt
Maike
M
Bewersdorff
Mayte
M
Rathkolb
Birgit
B
Müller
Marcel L
ML
Sandholzer
Nadja
N
Nitschke
Lars
L
Schiemann
Matthias
M
Mempel
Martin
M
Ollert
Markus
M
Neubauer
Antonie
A
Soewarto
Dian A
DA
Kremmer
Elisabeth
E
Ring
Johannes
J
Behrendt
Heidrun
H
Flaswinkel
Heinrich
H
D000477:Alkylating Agents; D000818:Animals; D005038:Ethylnitrosourea; D016678:Genome / Q000235:genetics*; D007073:Immunoglobulin E / Q000097:blood; D007153:Immunologic Deficiency Syndromes / Q000235:genetics* / Q000473:pathology; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D016296:Mutagenesis; D010641:Phenotype; D051746:ZAP-70 Protein-Tyrosine Kinase / Q000235:genetics
D000477:Alkylating Agents; D007073:Immunoglobulin E; D051746:ZAP-70 Protein-Tyrosine Kinase; C497262:Zap70 protein, mouse; D005038:Ethylnitrosourea