Phenotypes associated with this allele

• Allele Symbol: Irf4^tm1.1Rdf
• Allele Name: targeted mutation 1.1, Riccardo Dalla-Favera
• Allele ID: MGI:3712352
• Summary: 4 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Irf4^tm1.1Rdf/Irf4^tm1.1Rdf	involves: 129S1/Sv * 129S4/SvJae * C57BL/6	MGI:3712438
ht2	Irf4^tm1Rdf/Irf4^tm1.1Rdf	involves: 129S1/Sv * 129S4/SvJae * C57BL/6	MGI:3712441
cn3	Irf4^tm1Rdf/Irf4^tm1.1Rdf	involves: 129S1/Sv * 129S4/SvJae * C57BL/6	MGI:3712442
cn4	Ighg1^tm1(cre)Cgn/Ighg1^+ Irf4^tm1Rdf/Irf4^tm1.1Rdf	involves: 129P2/OlaHsd * 129S1/Sv * 129S4/SvJaeSor * C57BL/6	MGI:3712440

Genotype
MGI:3712438

hm1

• Allelic Composition: Irf4^tm1.1Rdf/Irf4^tm1.1Rdf
• Genetic Background: involves: 129S1/Sv * 129S4/SvJae * C57BL/6

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

immune system

abnormal B cell differentiation ( J:112643 )

• mice have decreased percentages of IgD+, CD23+, and PNA+ B cells compared to controls

absent spleen germinal center ( J:112643 )

• complete absence of germinal centers in spleen

abnormal B cell physiology ( J:112643 )

• in culture, B cells treated with LPS to induce plasmablastic differentiation do not differentiate, whereas wild-type B cells do

decreased B cell proliferation ( J:112643 )

• rate is slower than wild-type cells

decreased IgG1 level ( J:112643 )

• percentage of cells expressing IgG1 after stimulation with CD40 plus Il-4 is much lower than in wild-type cultures after same number of cell divisions

hematopoietic system

abnormal B cell differentiation ( J:112643 )

• mice have decreased percentages of IgD+, CD23+, and PNA+ B cells compared to controls

absent spleen germinal center ( J:112643 )

• complete absence of germinal centers in spleen

abnormal B cell physiology ( J:112643 )

• in culture, B cells treated with LPS to induce plasmablastic differentiation do not differentiate, whereas wild-type B cells do

decreased B cell proliferation ( J:112643 )

• rate is slower than wild-type cells

decreased IgG1 level ( J:112643 )

• percentage of cells expressing IgG1 after stimulation with CD40 plus Il-4 is much lower than in wild-type cultures after same number of cell divisions

cellular

decreased B cell proliferation ( J:112643 )

• rate is slower than wild-type cells

Genotype
MGI:3712441

ht2

• Allelic Composition: Irf4^tm1Rdf/Irf4^tm1.1Rdf
• Genetic Background: involves: 129S1/Sv * 129S4/SvJae * C57BL/6

immune system

immune system phenotype ( J:112643 )

N • following immunization with a T-dependent antigen, mice show normal percentages of splenic IgD+. CD23+, and PNA+ B cells, germinal centers, and IgG1 and IgM plasma cells, similar to heterozygous Irf4^tm1.1Pth mice or doubly heterozygous Irf4^tm1Pth / Irf4^tm1.1Pth mice

N • splenic and peripheral blood B cells show normal T-dependent B cell responses NP hapten, and V(H) rearrangements show similar frequencies of somatic hypermutation

Genotype
MGI:3712442

cn3

• Allelic Composition: Irf4^tm1Rdf/Irf4^tm1.1Rdf
• Genetic Background: involves: 129S1/Sv * 129S4/SvJae * C57BL/6

immune system

abnormal B cell physiology ( J:112643 )

• mature B cells treated with TAT-cre to achieve in vitro deletion of Irf4 are unable to differentiate into plasma cells after LPS treatment, suggesting that it is not a consequence of the developmental stage of the B cells in mutants vs wild-type

hematopoietic system

abnormal B cell physiology ( J:112643 )

• mature B cells treated with TAT-cre to achieve in vitro deletion of Irf4 are unable to differentiate into plasma cells after LPS treatment, suggesting that it is not a consequence of the developmental stage of the B cells in mutants vs wild-type

Genotype
MGI:3712440

cn4

• Allelic Composition: Ighg1^tm1(cre)Cgn/Ighg1⁺; Irf4^tm1Rdf/Irf4^tm1.1Rdf
• Genetic Background: involves: 129P2/OlaHsd * 129S1/Sv * 129S4/SvJaeSor * C57BL/6

immune system

immune system phenotype ( J:112643 )

N • mice form germinal centers and have similar numbers of PNA^hi, B220+ B cells in spleen

abnormal class switch recombination ( J:112643 )

• following CD40 and Il-4 stimulation, mice have smaller fraction of class-switched cells than control mice (7.4% vs 26.3%); defect appears to be downstream of Cgamma1 germline transcription

absent plasma cells ( J:112643 )

• 14 days after immunization with sheep red blood cells, mutants are observed to lack plasma cells, as recognized by CD138 expression, in spleen, peripheral blood and bone marrow

abnormal memory B cell morphology ( J:112643 )

• memory B cell generation occurs in mutants after immunization with NP-KLH, but the population is maintained only partly over time; numbers of NP-binding cells are much lower 42 days after immunization compared to controls

• mice receiving a secondary immunization with antigen lack plasmablasts in the spleen that bind NP, are CD138 +ve and have low B220 expression, indicating that memory B cells cannot differentiate into plasma B cells upon antigen restimulation; B cells also lack IgG1 secretion after restimulation

decreased IgG1 level ( J:112643 )

• mice have much lower titer of IgG1 specific for the hapten NP (nitrophenylacetyl) than controls after immunization with NP coupled to keyhole limpet hemocyanin, but titers of other immunoglobulin classes are similar to levels in controls

hematopoietic system

abnormal class switch recombination ( J:112643 )

• following CD40 and Il-4 stimulation, mice have smaller fraction of class-switched cells than control mice (7.4% vs 26.3%); defect appears to be downstream of Cgamma1 germline transcription

absent plasma cells ( J:112643 )

• 14 days after immunization with sheep red blood cells, mutants are observed to lack plasma cells, as recognized by CD138 expression, in spleen, peripheral blood and bone marrow

abnormal memory B cell morphology ( J:112643 )

• memory B cell generation occurs in mutants after immunization with NP-KLH, but the population is maintained only partly over time; numbers of NP-binding cells are much lower 42 days after immunization compared to controls

• mice receiving a secondary immunization with antigen lack plasmablasts in the spleen that bind NP, are CD138 +ve and have low B220 expression, indicating that memory B cells cannot differentiate into plasma B cells upon antigen restimulation; B cells also lack IgG1 secretion after restimulation

decreased IgG1 level ( J:112643 )

• mice have much lower titer of IgG1 specific for the hapten NP (nitrophenylacetyl) than controls after immunization with NP coupled to keyhole limpet hemocyanin, but titers of other immunoglobulin classes are similar to levels in controls