Wild-type (WT) mice are irradiated, destroying all of their bone marrow cells including CD34+ hematopoietic stem cells (HSC). CD34+ HSC is isolated from (1) an untreated wild-type syngeneic control mouse, and (2) various immune gene mutant (-/- null) donor mice. The CD34+ HSC from the different mouse genotypes is injected into the wild-type irradiated recipient mice. Predict the reconstitution of the hematopoietic system in each of the recipient mice (+ or -). Solution Answer - Hematopoietic cells reconstituted in recipient CD34+HSC Doner GenotypeErythrocytes macrophages T cells B cells Wild Type mouse + + + + CD19(-/-)mouse + + + - Rag1/2(-/-)mouse + + - - erythropoietin EPO(-/-) - + + + AIRE(-/-)mouse + + + + explaination -Wild type mouse has normal CD34+HSC which is responsible to diffentiate into all type of immune cells in bone marrow. Whwn this CD34+HSC from wild type mouse injected into recipient mouse its bone marrow produce all type of immune cells. CD19 is a B cell lymphocyte antigen It is a protein which is coded by CD19 gene. it is found on the surface of B cells and helps in its proliferation and differenciation.CD34+HSC from doner who lack CD19 gene when injected into recipient mouse,It will be unable to produce B cell. Rag 1/2 also known as recombination activating gene codes a protein which paly an important role in recombination of the gene of immunoglobuline and T cell receptor marker.two gene products of recombination activating gene are Rag 1 and Rag 2 protein.These two rag protein are essential to the generation of mature Bcells and Tcells. .CD34+Hsc from doner who lack the gene codes gor Rag1/2 protein when injected to the recipient mouse, recipient mousewill be unable to produce mature B and T cells. Erythropoietin EPO is a protein harmone secreated by kidney in responce to less oxygen/Heamoglobine in blood.erythropoietin stimulates bone marrow to produce more Red blood cells (erythrocytes) which contain Heamoglobine ( an Oxygen carrier) and supply required amount of oxygen to the body by mean of blood flow through the body. when CD34+HSC from doner lack the gene codes for Erythropoietin injected into recipient mouse,it bone marrow will be unable to produce erythrocytes. AIRE is an auto immune regulator protein encoded by AIRE gene.It controles a mechanism that prevent T cells (an important cell for immune response) from attacking the self body antigen.T cells recognizes antigen which are expresed on the surface of antigen presenting cell by T cell receptors present on T cells and produce Immune responce against that antigen. In autoimmune diseases T cell Recognize self antigen and produce immune response against self antigen which leads to sever problem in self body.AIRE protein play an important role to controle these kind of autoimmune disorders by the removel of T cell through apoptosis while T cells are still in thymus. When CD34+HSC from doner WHICh lake the gene for AIRE protein injected into recipient mouse.Reci.

1. Wild-type (WT) mice are irradiated, destroying all of their bone marrow cells including CD34+
hematopoietic stem cells (HSC). CD34+ HSC is isolated from (1) an untreated wild-type
syngeneic control mouse, and (2) various immune gene mutant (-/- null) donor mice. The CD34+
HSC from the different mouse genotypes is injected into the wild-type irradiated recipient mice.
Predict the reconstitution of the hematopoietic system in each of the recipient mice (+ or -).
Solution
Answer -
Hematopoietic cells reconstituted in recipient
CD34+HSC
Doner GenotypeErythrocytes macrophages T cells B cells
Wild Type mouse + + + +
CD19(-/-)mouse + + + -
Rag1/2(-/-)mouse + + - -
erythropoietin EPO(-/-) - + + +
AIRE(-/-)mouse + + + +
explaination -Wild type mouse has normal CD34+HSC which is responsible to diffentiate into
all type of immune cells in bone marrow. Whwn this CD34+HSC from wild type mouse injected
into recipient mouse its bone marrow produce all type of immune cells.
CD19 is a B cell lymphocyte antigen It is a protein which is coded by CD19 gene. it is found on
the surface of B cells and helps in its proliferation and differenciation.CD34+HSC from doner
who lack CD19 gene when injected into recipient mouse,It will be unable to produce B cell.
Rag 1/2 also known as recombination activating gene codes a protein which paly an important
role in recombination of the gene of immunoglobuline and T cell receptor marker.two gene
products of recombination activating gene are Rag 1 and Rag 2 protein.These two rag protein are
essential to the generation of mature Bcells and Tcells. .CD34+Hsc from doner who lack the
gene codes gor Rag1/2 protein when injected to the recipient mouse, recipient mousewill be
unable to produce mature B and T cells.
Erythropoietin EPO is a protein harmone secreated by kidney in responce to less
oxygen/Heamoglobine in blood.erythropoietin stimulates bone marrow to produce more Red
blood cells (erythrocytes) which contain Heamoglobine ( an Oxygen carrier) and supply required
amount of oxygen to the body by mean of blood flow through the body. when CD34+HSC from
doner lack the gene codes for Erythropoietin injected into recipient mouse,it bone marrow will
be unable to produce erythrocytes.
AIRE is an auto immune regulator protein encoded by AIRE gene.It controles a mechanism that

2. prevent T cells (an important cell for immune response) from attacking the self body antigen.T
cells recognizes antigen which are expresed on the surface of antigen presenting cell by T cell
receptors present on T cells and produce Immune responce against that antigen. In autoimmune
diseases T cell Recognize self antigen and produce immune response against self antigen which
leads to sever problem in self body.AIRE protein play an important role to controle these kind of
autoimmune disorders by the removel of T cell through apoptosis while T cells are still in
thymus.
When CD34+HSC from doner WHICh lake the gene for AIRE protein injected into recipient
mouse.Recipient mouse will be unable to produce AIRE protein and thus T cells will not be
eleminated by immune system.