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Prepublished online as a Blood First Edition Paper on September 19, 2002; DOI 10.1182/blood-2002-07-1969.
GENE THERAPY
From the Sidney Kimmel Cancer Center, San Diego, CA.
Transgenic mice have been generated that carry a CD45 minigene
under control of the human leukocyte function-associated antigen (LFA-1, CD11a) promoter. CD45-null mice carrying the transgene exhibit
the lymphocyte lineage-specific isoform expression patterns of
wild-type mice. Furthermore, these mice have normal thymocyte development and peripheral T-cell numbers. The proliferative ability of
T cells in response to mitogens and antigen also is regained, as
is B-cell responsiveness to anti-IgM. The antibody response to
antigen is also restored and is similar to that of normal mice. Therefore, introduction of a functional CD45 minigene is sufficient to
overcome the principal severe combined immunodeficiency
(SCID)-associated defects and represents a potential route to a gene
therapy for human CD45-deficent SCID.
(Blood. 2003;101:849-855) CD45 is a structurally heterogeneous, transmembrane
protein-tyrosine phosphatase found exclusively on nucleated cells of
hematopoietic origin. The heterogeneity results from differential RNA
splicing of 6 exons in the extracellular domain.1-3 The
isoforms are expressed in a cell type-specific pattern. B cells
predominantly express the isoform containing all exons.4,5
Thymocytes express the lowest molecular weight isoforms resulting from
the removal of 3 and 4 exons.2-4 T cells have a varied
isoform expression pattern that is dependent upon the differentiation
state, function, and prior antigenic exposure.3
In addition to the structural heterogeneity of CD45 proteins, CD45
allelic differences also have been noted. At least 3 CD45 alleles in
inbred mice strains have been identified based on antigenic differences
and polymorphic sequence variations.2,6,7 The Ly5a (CD45.1) and Ly5c
alleles are found only in a few strains, while the
Ly5b (CD45.2) allele is expressed by most of the
established lines. The sequence differences between the 3 alleles produce proteins that differ in their reactivity to specific
monoclonal antibodies.7
CD45 has been shown to be essential for T-cell
development8-10 and for the function of both T and B
lymphocytes.8-15 In CD45-null mice, thymocyte development
is blocked, resulting in few peripheral T cells. The function of these
T cells in the periphery also is defective, and they do not proliferate
in the presence of activators or mitogens. B-cell maturation in the
CD45-negative mice is not effected by the CD45 deficiency, although
their proliferative response to anti-IgM is abrogated.9,10
With regard to lymphocyte function, CD45 is essential for signaling
through the T- as well as B-cell antigen
receptors11-14,16,17 and is required for positive and
negative regulation of the Src family kinases associated with these
receptors.18-21
Human severe combined immunodeficiencies (SCIDs) are a group of genetic
diseases in which T-cell development is blocked and other lymphoid
lineages are variably affected.22,23 The genetic defects
of many forms of the disease now have been identified, including
mutations in the common We have generated a CD45 minigene encoding the CD45.1 allele in which 2 cDNA regions spanning exons 1b-3 and 9-33 flank genomic DNA containing
the alternatively spliced exons 4-8. Transcriptional regulation of the
minigene from the native CD45 promoter region was ineffective, but the
human leukocyte function-associated antigen (LFA-1) promoter, which
has tissue-specific expression characteristics similar to CD45,
produced high levels of CD45 expression in lymphoid cell
lines.27 The demonstration that correctly spliced, cell lineage-specific CD45 mRNAs were produced in both T- and B-cell lines
indicates that the minigene construct has many of the expression properties of the endogenous CD45 gene. These expression
characteristics in vitro were encouraging; however, the question
remains whether the minigene can supply functional CD45 isoforms to the
various leukocyte lineages. To determine whether the minigene LFAiT200 could restore the functional and developmental properties of the immune
system, we generated transgenic CD45-null mice carrying the
minigene. The introduction of the CD45 minigene is sufficient to
overcome the SCID-associated defects and, with an appropriate delivery
system, represents a potential gene therapy for human CD45-deficient SCID.
Mice
Quantitation of transgene copy number
Proliferation assays T-cell proliferation assays were conducted in 96-well microtiter plates using 1 × 106 cells per well for spleen cells isolated from CD45-null mice and 2 × 105 spleen cells per well for all other strains. T-cell activators were concanavalin A (ConA) (Sigma, St Louis, MO) at 1 µg/mL or a combination of anti-CD3 and anti-CD28 (PharMingen, La Jolla, CA) at 2 µg/mL each. For the mixed lymphocyte reaction (MLR) assay, 4 × 105 responder cells were added to 2 × 105, 4 × 105, and 8 × 105 irradiated (2000 rad) spleen stimulator cells from major histocompatibility complex (MHC)-allogeneic SJL mice or irradiated responder cells. In the anti-IgM proliferation assay, 20 µg/mL of the F(ab')2 fragment of goat anti-mouse IgM (Jackson ImmunoResearch Laboratories, West Grove, PA) was incubated with 2 × 105 spleen cells per well. For bacterial lipopolysaccharide (LPS) stimulation assays 15 µg/mL of LPS (Difco Laboratories, Detroit, MI) were added to 1 × 105 spleen cells. All cells were cultured in RPMI 1640 supplemented with 2 mM L-glutamine, 10% fetal bovine serum, 0.05 mM 2-mercaptoethanol, 100 units/mL penicillin, and 100 µg/mL streptomycin. Media components were from Irvine Scientific (Irvine, CA). All cultures were prepared in triplicate and incubated at 37°C in 5% CO2. Cultures were given 1 µCi (0.037 MBq)/well thymidine [methyl-3H] on day 2 except for MLR cultures, which received the labeled nucleotide on day 5. After overnight incubation, cells were harvested on a Tomtec Cell Harvestor 96 Mach III, and [3H]thymidine incorporation was measured on a Wallac 1450 Microbeta TriLux liquid scintillation and luminescence counter. Results are expressed as cpm, experimental minus control counts. In the MLR assay, the control counts were from cultures incubated with
irradiated responder cells.
Flow cytometry Cells were labeled with fluorescence-tagged monoclonal antibodies and analyzed as described27 using the following antibodies: R-phycoerythrin (PE)-conjugated anti-CD4 (Caltag, Burlingame, CA), Tri Color-conjugated anti-CD8 (Caltag), PE-conjugated anti-CD11a (PharMingen), allophycocyanin (APC)-conjugated anti-CD11b (Caltag), PE-conjugated anti-CD19 (Caltag), fluorescein isothiocyanate (FITC)-conjugated anti-CD44 (Caltag), FITC-conjugated anti-CD45.1 (PharMingen), FITC-conjugated anti-CD45.2 (PharMingen), biotin-conjugated anti-CD45.2 (PharMingen), R-PE-conjugated anti-CD45RB (PharMingen), biotin-conjugated anti-CD62L (Caltag), Tri Color-conjugated anti-F4/80 (Ly-71) (Caltag), SaV-APC (PharMingen), SaV-Tri Color (Caltag), and conjugated Ig2a and Ig2b isotype controls (PharMingen). Cells from spleen and thymus were used for analysis of lymphoid and myeloid cells. For the study of naive and memory CD4+ cells, mice were immunized subcutaneously at the base of the tail with 1 mg dinitrophenyl-keyhole limpet hemocyanin conjugate (DNP-KLH) in complete Freund adjuvant (CFA). Draining inguinal and para-aortic lymph nodes were obtained 5 days after immunization.Reverse transcription and polymerase chain reaction Total RNA was isolated from spleen and thymus using TRIZOL (Life Technologies, Gaithersburg, MD) following manufacturer's directions. Spleen cells were untreated and exposed for 3 days to ConA or LPS. Reverse transcription-polymerase chain reaction (RT-PCR) was performed using the GeneAmp RNA PCR kit (Applied Biosystems, Foster City, CA) according to manufacturer's directions. The antisense oligonucleotide used for both cDNA synthesis and PCR amplification, 5'-GGAGCACATGAGTCATTAGACACACTGATG-3', consists of bases 155-184 of CD45 exon 9. The sense primer includes bases 21-51 of exon 2 and has the sequence 5'-GCACAGCTGATCTCCAGATATGACCATGGGT-3'. cDNA was synthesized for 15 minutes at 42°C followed by inactivation of reverse transcriptase for 5 minutes at 95°C. The first PCR cycle was 3 minutes at 94°C, 1 minute at 70°C, and 2 minutes at 72°C. Cycles 2-24 were 1 minute at 94°C, 1 minute at 70°C, and 2 minutes at 72°C. The amplified products were separated on an alkaline agarose gel and identified as described previously.28Immunization and ELISA From each mouse type transgenic F, C57BL/6, and
CD45-null 5 mice were immunized by intraperitoneal injection of 0.1 mg DNP-KLH (Calbiochem, San Diego, CA) in 0.1 mL CFA (Sigma). Mice were
bled 7, 14, and 21 days after immunization and serum prepared.
The enzyme-linked immunosorbent assay (ELISA) was performed as described.29 Briefly, wells were coated overnight with 0.05 mg dinitrophenyl-bovine serum albumin (DNP-BSA) in 0.1 M carbonate buffer, pH 9.6, washed with phosphate-buffered saline (PBS), blocked with 1% BSA/PBS, washed with PBS, and incubated with serial dilutions of mouse serum for 4 hours at room temperature. Rabbit anti-mouse IgM or IgG at a dilution of 1:1000 was added for 2 hours at room temperature, washed with PBS, and incubated overnight at 4°C with goat anti-rabbit IgG conjugated to alkaline phosphatase (Kirkegaard and Perry Laboratories, Gaithersburg, MD) at a dilution of 1:2000. Following 3 washes with PBS, 10 µg 4-methylumbelliferyl-phosphate (Sigma) in carbonate buffer was added for 30 minutes and fluorescence measured with excitation at 360 nm and emission at 440 nm in a fluorescence plate reader (Fluoroskan, Titertek). Mouse anti-trinitrophenyl-IgM antibody (Pharmingen) and anti-trinitrophenyl-IgG antibody (gift of Dr Phyllis Linton, Sidney Kimmel Cancer Center, San Diego, CA) were used for the standard curves. The serum anti-DNP IgM and anti-DNP IgG levels were calculated from duplicate wells of each dilution from 5 different mice.
Generation of transgenic mice The 20-kb CD45 expression fragment of pLFAiT200 (Figure 1) was injected into fertilized mouse oocytes for the production of transgenic mice. Three founder mice were initially identified by PCR amplification of minigene-specific sequence from genomic DNA isolated from tail and subsequently confirmed by Southern analysis. The 3 founders have similar properties, and here we report our findings with transgenic mice from founder F. The number of integrated copies of the transgene in transgenic F was determined to be approximately 15, with all copies transmitted to offspring as a single inheritable unit, indicating integration of all copies at one site. The transgene locus was placed on a CD45-negative background through matings with the exon 9-disrupted CD45-null mouse (CD45.2 /).9 Unless specifically stated
otherwise, reference to the transgenic mouse indicates the transgene is
on the CD45.2/ background.
CD45.1 expression The expression of the transgene was investigated by flow cytometry of spleen cells labeled with monoclonal antibodies specific for CD45.1 and CD45.2 (Figure 2). As expected for the controls, high levels of CD45.2 protein are detected on C57BL/6 spleen cells, but no CD45.1 protein is found. Spleen cells from SJL/J mice express high amounts of CD45.1 but not CD45.2. No CD45.2 or CD45.1 protein is observed on cells isolated from CD45-null mice. Lymphocytes from transgenic mice show CD45.1 protein levels that approach those of CD45.1 expression in SJL/J mice. Both T (CD4+ and CD8+) and B lymphocytes (CD19+) and myeloid lineages (F4/80+ and CD11b+) express significant levels of CD45.1 protein that are comparable to those observed in C57BL/6 mice (Figure 3).
Since the human LFA-1 promoter drives CD45.1 transcription in the
transgene, the expression characteristics of CD45.1 were compared with
those of endogenous LFA-1 and CD45.2. Spleen cells were labeled with
anti-CD45.1, anti-CD45.2, or anti-CD11a (LFA-1). In C57BL/6 mice, the
CD45.2-positive cells are also LFA-1 positive with variable levels of
LFA-1 expression (Figure 4A). The
brightest third of the LFA+CD45.2+ cells
consists primarily of CD4+ and CD8+ T cells
(data not shown). CD19+ B cells are in the less brightly
labeled population. In the transgenic mouse the 2 populations of
LFA+ CD45.1+ cells are more clearly defined.
The labeling properties of the LFA+ population containing B
cells closely resemble those of wild-type cells by exhibiting lower LFA
and higher CD45 expression than the T-cell components (Figure 4A).
However, the more brightly labeled LFA+ cells of the T-cell
lineages are more heterogeneous with respect to CD45 expression and
generally express less CD45 than their wild-type counterparts (Figures
3-4A). Importantly, in transgenic mice hemizygous for CD45.2, all cells
positive for CD45.1 are also positive for CD45.2 and vice versa (Figure
4B).
The CD45 isoform expression pattern from the transgene was evaluated in spleen cells from C57BL/6 and transgenic mice using monoclonal antibodies specific for exon 4 (CD45RA), exon 5 (CD45RB), or exon 6 (CD45RC) and flow cytometry. The percentage of positive cells with each of these antibodies is very similar for the transgenic mice and mice expressing the endogenous CD45 gene (CD45RA, 56% ± 6%; CD45RB, 80% ± 5%; CD45RC, 60% ± 4%). The similarity of isoform expression characteristics of transgenic and
normal mice was confirmed through RT-PCR analysis. Lymphocytes from the
spleen and thymus of C57BL/6, CD45-null, and transgenic mice were
isolated. Total RNA was purified from untreated spleen and thymus cells
and from spleen cells treated with ConA or LPS for 3 days. The CD45
isoforms were identified by RT-PCR, using primers that flank the region
of alternatively spliced exons, allowing all isoforms to be detected
(Figure 5). No CD45 mRNA was detected in
cells from the CD45 knockout mouse with the conditions used. Multiple
isoforms were observed in C57BL/6 spleen cells, as expected of a
mixture of leukocyte populations. The same expression pattern is found
in the spleen cells of the transgenic mouse. ConA-induced T-cell blasts
show a reduction of the high molecular weight isoforms and an increase
in the low molecular weight forms in both the C57BL/6 and transgenic
mice. Enrichment of the B-cell population by activation of B-cell
proliferation with LPS results in an increase in the proportion of high
molecular weight isoforms. Primarily, the 789 and 89 isoforms are
expressed in the thymus of C57BL/6 and transgenic mice.
CD45 is commonly used to distinguish naive (CD45RBhi) and
memory (CD45RBlo) T cells.31 To determine
whether naive and memory T cells retain the same characteristic shift
in isoform expression in the transgenic mice, we immunized transgenic
and wild-type mice with DNP-KLH and analyzed the CD4+
T-cell population. Draining lymph nodes were isolated 5 days after immunization, and the cells were stained with antibodies specific
for CD44, CD62L, CD4, and CD45RB. In both wild-type and transgenic mice
the CD4+, CD44lo, CD62Lhi cells are
CD45RBhi as expected for naive T cells,31 and
the percentage of CD45RBhi cells is essentially identical,
89% in wild-type and 88% in transgenic mice (Figure
6). The CD4+ cells expressing
the CD44hi, CD62Llo memory phenotype were
primarily CD45RBlo for both wild-type and transgenic mice;
73% in C57BL/6 and 64% in transgenic mice (Figure 6).
Thymocyte development and T-cell function The CD45-null mutation causes a block in T-cell development at the CD4+CD8+ stage, resulting in reduced numbers of mature, single positive thymocytes.8-10 The presence of the CD45.1 transgene restores CD4+ and CD8+ single positive thymic T cells in the transgenic mice (Figure 7; Table 1). The restoration of thymocyte development results in increased numbers of mature T cells in the spleens of these mice (Figure 7; Table 1).
The functional capabilities of the peripheral T cells were determined
by proliferation assays of spleen cells activated with ConA, a mixture
of anti-CD3 and anti-CD28, or MHC-allogeneic stimulator cells. As
expected, proliferative responses to both ConA and anti-CD3/CD28 are
completely abrogated in the CD45-null mice (Figure
8A). Expression of the CD45.1 transgene
restores these proliferative responses to normal levels. Furthermore,
in contrast to CD45-null cells, transgenic spleen cells are capable of
normal levels of proliferation in reaction to allogeneic stimulator
cells (Figure 8A).
B-cell function B-cell development is not impaired in CD45-deficient mice.9 Although the B cells of these mice respond to mitogenic stimulation by LPS, they do not proliferate in the presence of anti-IgM and do not produce an antibody response to antigen.9 Spleen cells isolated from transgenic, CD45-null, and C57BL/6 mice were activated with anti-IgM or LPS. The expression of the CD45.1 transgene in the knockout mice restores a substantial proliferative response to anti-IgM (Figure 8B). Responses to LPS are normal (Figure 8B).The ability of the CD45.1 transgenic mice to mount a primary immune
response was examined. C57BL/6, transgenic, and CD45-null mice
were immunized with DNP-KLH. Mice were bled 7, 14, and 21 days after
immunization, and sera from each mouse were analyzed separately by
ELISA for the presence of anti-DNP IgM and IgG antibodies. The
CD45-null mice showed little to no antibody production, as expected
(Figure 9). The titers of anti-DNP IgM
and IgG in the sera from the transgenic mice were comparable to those
in the C57BL/6 mice (Figure 9), with the peak response occurring 14 days after immunization for both.
The data presented demonstrate that the LFA-driven CD45.1 minigene in a CD45-null background restores normal splicing characteristics in the hematopoietic cells that express CD45. Importantly, the developmental characteristics of T cells and the functional properties of both T and B cells also are restored. Multiple lines of evidence demonstrate that the LFA-1 controlled CD45.1 transgene is expressed in a pattern characteristic of the endogenous CD45 gene. Flow cytometry data indicate that in transgenic mice hemizygous for CD45.2, all cells positive for CD45.1 were positive also for CD45.2, strongly suggesting that the transgene is expressed in the same cells that express the endogenous gene. Furthermore the major hematopoietic lineages, lymphoid and myeloid, express the CD45.1 transgene. Both RT-PCR and flow cytometry results confirm that alternative splicing of transcripts from the CD45.1 transgene are accurately produced in vivo, since the correct cell type-specific isoform expression patterns are generated. Also, naive and memory CD4+ T cells exhibit the expected CD45RB isoform expression characteristics. Comparison of endogenous LFA-1 and CD45.2 expression with that of the LFA-1-controlled CD45.1 transgene showed that the transgenic B-cell population has characteristics closely resembling the wild-type cells, whereas the transgenic T-cell lineages express less CD45 compared to wild type. The reason is not known but may be due to the particular properties of the transgene itself, such as the expression characteristics of the LFA-1 promoter. Another possibility is that the integration site has an effect on transgene expression in T cells. The most important issue, however, is whether the presence of the CD45.1 transgene can overcome the developmental and functional defects resulting from the CD45-null mutation. The presence of the CD45.1 transgene fully restores the number of CD4+ and CD8+ single positive T cells in the thymus and, as a result, wild-type numbers of mature T cells are present in the spleen. Proliferation assays in response to antigen demonstrated that these T cells regained normal signal transduction characteristics through the antigen receptor complex. Therefore, these data confirm that the presence of the CD45.1 minigene restores both T-cell development and function. With respect to B-cell function in the transgenic mice, the proliferative response to activation by anti-IgM is restored and suggests that these mice are capable of a humoral immune response to antigen. To test this parameter, the serum anti-DNP IgM and IgG levels of DNP-KLH immunized mice were assayed by ELISA and were found to be similar in both the transgenic and C57BL/6 mice. Thus, the presence of the CD45.1 transgene restores the ability to produce a significant antibody response in vivo. Since the SCID phenotype exhibited by the CD45-null mice is overcome as a result of the expression of the CD45.1 minigene, a new opportunity can be considered now for treating the CD45-null form of human SCID. A similar human CD45 minigene, together with a gene transfer vehicle that can efficiently transfer the 20-kb construct into human hematopoietic cells, offers the potential for gene therapy for this otherwise life-threatening genetic disease.
The authors wish to acknowledge Drs Phyllis Linton, Joy Phillips, and Marilyn Thoman for the donation of their time for in-depth discussions.
Submitted July 3, 2002; accepted September 9, 2002.
Prepublished online as Blood First Edition Paper, September 19, 2002; DOI 10.1182/blood-2002-07-1969.
Supported by a grant from the National Institutes of Health (AI40259).
The publication costs of this article were defrayed in part by page charge payment. Therefore, and solely to indicate this fact, this article is hereby marked "advertisement" in accordance with 18 U.S.C. section 1734.
Reprints: William C. Raschke, 10835 Altman Row, San Diego, CA 92121; e-mail: braschke{at}skcc.org.
1. Chang HL, Lefrancois L, Zaroukian MH, Esselman WJ. Developmental expression of CD45 alternate exons in murine T cells: evidence of additional alternate exon use. J Immunol. 1991;147:1687-1693[Abstract]. 2. Zebedee SL, Barritt D, Epstein R, Raschke WC. Analysis of Ly5 chromosome 1 position using allelic differences and recombinant inbred mice. Eur J Immunogenet. 1991;18:155-163[Medline] [Order article via Infotrieve]. 3. Virts E, Barritt D, Raschke WC. Expression of CD45 isoforms lacking exons 7, 8 and 10. Mol Immunol. 1998;35:167-176[CrossRef][Medline] [Order article via Infotrieve].
4.
Shen FW, Saga Y, Litman G, et al.
Cloning of Ly-5 cDNA.
Proc Natl Acad Sci U S A.
1985;82:7360-7363
5.
Thomas ML, Reynolds PJ, Chain A, Ben-Neriah Y, Trowbridge IS.
B-cell variant of mouse T200 (Ly-5): evidence for alternative mRNA splicing.
Proc Natl Acad Sci U S A.
1987;84:5360-5363 6. Seldin MF, D'Hoostelaere LA, Steinberg AD, Saga Y, Morse HC III. Allelic variants of Ly-5 in inbred and natural populations of mice. Immunogenetics. 1987;26:74-78[CrossRef][Medline] [Order article via Infotrieve]. 7. Raschke WC, Hendricks M, Chen CM. Genetic basis of antigenic differences between three alleles of Ly5 (CD45) in mice. Immunogenetics. 1995;41:144-147[Medline] [Order article via Infotrieve]. 8. Kishihara K, Penninger J, Wallace VA, et al. Normal B lymphocyte development but impaired T cell maturation in CD45-exon6 protein tyrosine phosphatase-deficient mice. Cell. 1993;74:143-156[CrossRef][Medline] [Order article via Infotrieve].
9.
Byth KF, Conroy LA, Howlett S, et al.
CD45-null transgenic mice reveal a positive regulatory role for CD45 in early thymocyte development, in the selection of CD4+CD8+ thymocytes, and B cell maturation.
J Exp Med.
1996;183:1707-1718 10. Mee PJ, Turner M, Basson MA, Costello PS, Zamoyska R, Tybulewicz VL. Greatly reduced efficiency of both positive and negative selection of thymocytes in CD45 tyrosine phosphatase-deficient mice. Eur J Immunol. 1999;29:2923-2933[CrossRef][Medline] [Order article via Infotrieve]. 11. Koretzky GA, Picus J, Thomas ML, Weiss A. Tyrosine phosphatase CD45 is essential for coupling T-cell antigen receptor to the phosphatidyl inositol pathway. Nature. 1990;346:66-68[CrossRef][Medline] [Order article via Infotrieve].
12.
Justement LB, Campbell KS, Chien NC, Cambier JC.
Regulation of B cell antigen receptor signal transduction and phosphorylation by CD45.
Science.
1991;252:1839-1842
13.
Koretzky GA, Picus J, Schultz T, Weiss A.
Tyrosine phosphatase CD45 is required for T-cell antigen receptor and CD2-mediated activation of a protein tyrosine kinase and interleukin 2 production.
Proc Natl Acad Sci U S A.
1991;88:2037-2041 14. Lane PJ, Ledbetter JA, McConnell FM, et al. The role of tyrosine phosphorylation in signal transduction through surface Ig in human B cells: inhibition of tyrosine phosphorylation prevents intracellular calcium release. J Immunol. 1991;146:715-722[Abstract].
15.
Berger SA, Mak TW, Paige CJ.
Leukocyte common antigen (CD45) is required for immunoglobulin E-mediated degranulation of mast cells.
J Exp Med.
1994;180:471-476 16. Pingel JT, Thomas ML. Evidence that the leukocyte-common antigen is required for antigen-induced T lymphocyte proliferation. Cell. 1989;58:1055-1065[CrossRef][Medline] [Order article via Infotrieve].
17.
Weaver CT, Pingel JT, Nelson JO, Thomas ML.
CD8+ T-cell clones deficient in the expression of the CD45 protein tyrosine phosphatase have impaired responses to T-cell receptor stimuli.
Mol Cell Biol.
1991;11:4415-4422 18. Thomas ML, Brown EJ. Positive and negative regulation of Src-family membrane kinases by CD45. Immunol Today. 1999;20:406-411[CrossRef][Medline] [Order article via Infotrieve].
19.
D'Oro U, Ashwell JD.
Cutting edge: the CD45 tyrosine phosphatase is an inhibitor of Lck activity in thymocytes.
J Immunol.
1999;162:1879-1883 20. Ashwell JD, D'Oro U. CD45 and Src-family kinases: and now for something completely different. Immunol Today. 1999;20:412-416[CrossRef][Medline] [Order article via Infotrieve].
21.
Katagiri T, Ogimoto M, Hasegawa K, et al.
CD45 negatively regulates lyn activity by dephosphorylating both positive and negative regulatory tyrosine residues in immature B cells.
J Immunol.
1999;163:1321-1326 22. Fischer A. Severe combined immunodeficiencies (SCID). Clin Exp Immunol. 2000;122:143-149[CrossRef][Medline] [Order article via Infotrieve]. 23. Fischer A, Hacein-Bey S, Le Deist F, de Saint Basile G, Cavazzana-Calvo M. Gene therapy for human severe combined immunodeficiencies. Immunity. 2001;15:1-4[CrossRef][Medline] [Order article via Infotrieve].
24.
Tchilian EZ, Wallace DL, Wells RS, Flower DR, Morgan G, Beverley PC.
A deletion in the gene encoding the CD45 antigen in a patient with SCID.
J Immunol.
2001;166:1308-1313
25.
Cale CM, Klein NJ, Novelli V, Veys P, Jones AM, Morgan G.
Severe combined immunodeficiency with abnormalities in expression of the common leucocyte antigen, CD45.
Arch Dis Child.
1997;76:163-164 26. Kung C, Pingel JT, Heikinheimo M, et al. Mutations in the tyrosine phosphatase CD45 gene in a child with severe combined immunodeficiency disease. Nat Med. 2000;6:343-345[CrossRef][Medline] [Order article via Infotrieve].
27.
Virts EL, Raschke WC.
The role of intron sequences in high level expression from CD45 cDNA constructs.
J Biol Chem.
2001;276:19913-19920 28. Virts E, Barritt D, Siden E, Raschke WC. Murine mast cells and monocytes express distinctive sets of CD45 isoforms. Mol Immunol. 1997;34:1191-1197[CrossRef][Medline] [Order article via Infotrieve]. 29. Linton PL, Decker DJ, Klinman NR. Primary antibody-forming cells and secondary B cells are generated from separate precursor cell subpopulations. Cell. 1989;59:1049-1059[CrossRef][Medline] [Order article via Infotrieve].
30.
Saga Y, Tung JS, Shen FW, Pancoast TC, Boyse EA.
Organization of the Ly-5 gene.
Mol Cell Biol.
1988;8:4889-4895 31. Dutton RW, Bradley LM, Swain SL. T cell memory. Annu Rev Immunol. 1998;16:201-223[CrossRef][Medline] [Order article via Infotrieve].
© 2003 by The American Society of Hematology.
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  R. G. Panchal, R. L. Ulrich, S. B. Bradfute, D. Lane, G. Ruthel, T. A. Kenny, P. L. Iversen, A. O. Anderson, R. Gussio, W. C. Raschke, et al. Reduced Expression of CD45 Protein-tyrosine Phosphatase Provides Protection against Anthrax Pathogenesis J. Biol. Chem., May 8, 2009; 284(19): 12874 - 12885. [Abstract] [Full Text] [PDF]
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 B. E. Collins, O. Blixt, A. R. DeSieno, N. Bovin, J. D. Marth, and J. C. Paulson Masking of CD22 by cis ligands does not prevent redistribution of CD22 to sites of cell contact PNAS, April 20, 2004; 101(16): 6104 - 6109. [Abstract] [Full Text] [PDF]
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 S. Ogilvy, C. Louis-Dit-Sully, J. Cooper, R. L. Cassady, D. R. Alexander, and N. Holmes Either of the CD45RB and CD45RO Isoforms Are Effective in Restoring T Cell, But Not B Cell, Development and Function in CD45-Null Mice J. Immunol., August 15, 2003; 171(4): 1792 - 1800. [Abstract] [Full Text] [PDF]
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Top
Abstract
Introduction
-chain of cytokine receptors found in
X-linked SCID and alterations in several other genes, such as JAK-3
kinase, Rag-1, and Rag-2, which cause autosomal recessive
SCID.
