Phenotypes associated with this allele

• Allele Symbol: Mir155^tm1.1Brd
• Allele Name: targeted mutation 1.1, Allan Bradley
• Allele ID: MGI:3709881
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Mir155^tm1.1Brd/Mir155^tm1.1Brd	B6.129S7-Mir155^tm1.1Brd	MGI:3837361
hm2	Mir155^tm1.1Brd/Mir155^tm1.1Brd	B6.Cg-Mir155^tm1.1Brd Tyr^c-Brd	MGI:3711838

Genotype
MGI:3837361

hm1

• Allelic Composition: Mir155^tm1.1Brd/Mir155^tm1.1Brd
• Genetic Background: B6.129S7-Mir155^tm1.1Brd

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

immune system

decreased regulatory T cell number ( J:146268 )

• mice have a 2- to 3- fold reduction of CD4⁺ Foxp3⁺ T regulatory cells in the thymus and spleen of adult mice

• in 1 year old mice, the phenotype is milder with only a slight reduction in regulatory T cells present

• mixed bone marrow chimera experiments demonstrate T regulatory deficit occurs during development and is intrinsic to T cell precursors

hematopoietic system

decreased regulatory T cell number ( J:146268 )

• mice have a 2- to 3- fold reduction of CD4⁺ Foxp3⁺ T regulatory cells in the thymus and spleen of adult mice

• in 1 year old mice, the phenotype is milder with only a slight reduction in regulatory T cells present

• mixed bone marrow chimera experiments demonstrate T regulatory deficit occurs during development and is intrinsic to T cell precursors

Genotype
MGI:3711838

hm2

• Allelic Composition: Mir155^tm1.1Brd/Mir155^tm1.1Brd
• Genetic Background: B6.Cg-Mir155^tm1.1Brd Tyr^c-Brd

immune system

immune system phenotype ( J:121095 )

N • no gross defects in myeloid or lymphoid development are observed in mutants

abnormal CD4-positive, alpha beta T cell morphology ( J:121095 )

• number of Il-4 single producing cells is doubled in culture with nonpolarizing conditions (ThN)

increased T-helper 2 cell number ( J:121095 )

• commitment to Th2 pathway is increased; number of Il-4 producing cells in is increased

abnormal T-helper 1 cell morphology ( J:121095 )

• mutant Th1 cells produce elevated levels of CCL-5

decreased IgG1 level ( J:121095 )

• production of IgG1 by LPS and Il-4 stimulation of B cells is significantly reduced relative to controls

abnormal CD4-positive, alpha-beta T cell physiology ( J:121095 )

• uncommitted CD4+ T cells show reduced Ifng production after stimulation with CD3 and CD28 antibodies

• Ifng-producing cells are reduced 5-fold under sulture conditions nonpolarizing for T helper responses; under Th2 polarizing conditions Il-4, -5 and -10 production is elevated

abnormal dendritic cell physiology ( J:121095 )

• bone marrow-derived dendritic cells from mutants fail to efficiently activate T cells, but show normal levels of MHC-II and CD86 when stimulated with LPS in culture

increased susceptibility to bacterial infection ( J:121095 )

hematopoietic system

abnormal CD4-positive, alpha beta T cell morphology ( J:121095 )

• number of Il-4 single producing cells is doubled in culture with nonpolarizing conditions (ThN)

increased T-helper 2 cell number ( J:121095 )

• commitment to Th2 pathway is increased; number of Il-4 producing cells in is increased

abnormal T-helper 1 cell morphology ( J:121095 )

• mutant Th1 cells produce elevated levels of CCL-5

decreased IgG1 level ( J:121095 )

• production of IgG1 by LPS and Il-4 stimulation of B cells is significantly reduced relative to controls

abnormal CD4-positive, alpha-beta T cell physiology ( J:121095 )

• uncommitted CD4+ T cells show reduced Ifng production after stimulation with CD3 and CD28 antibodies

• Ifng-producing cells are reduced 5-fold under sulture conditions nonpolarizing for T helper responses; under Th2 polarizing conditions Il-4, -5 and -10 production is elevated