Immune Organs and Cells, Antigen, and Antibody, B-Cell, and T-Cell Development

2019 ◽  
pp. 29-96
Author(s):  
Shyamasree Ghosh
1996 ◽  
Vol 183 (4) ◽  
pp. 1707-1718 ◽  
Author(s):  
K F Byth ◽  
L A Conroy ◽  
S Howlett ◽  
A J Smith ◽  
J May ◽  
...  

The CD45 transmembrane glycoprotein has been shown to be a protein phosphotyrosine phosphatase and to be important in signal transduction in T and B lymphocytes. We have employed gene targeting to create a strain of transgenic mice that completely lacks expression of all isoforms of CD45. The spleens from CD45-null mice contain approximately twice the number of B cells and one fifth the number of T cells found in normal controls. The increase in B cell numbers is due to the specific expansion of two B cell subpopulations that express high levels of immunoglobulin (IgM) staining. T cell development is significantly inhibited in CD45-null animals at two distinct stages. The efficiency of the development of CD4-CD8- thymocytes into CD4+ CD8+ thymocytes is reduced by twofold, subsequently the frequency of successful maturation of the double positive population into mature, single positive thymocytes is reduced by a further four- to fivefold. In addition, we demonstrate that CD45-null thymocytes are severely impaired in their apoptotic response to cross-linking signals via T cell receptor (TCR) in fetal thymic organ culture. In contrast, apoptosis can be induced normally in CD45-null thymocytes by non-TCR-mediated signals. Since both positive and negative selection require signals through the TCR complex, these findings suggest that CD45 is an important regulator of signal transduction via the TCR complex at multiple stages of T cell development. CD45 is absolutely required for the transmission of mitogenic signals via IgM and IgD. By contrast, CD45-null B cells proliferate as well as wild-type cells to CD40-mediated signals. The proliferation of B cells in response to CD38 cross-linking is significantly reduced but not abolished by the CD45-null mutation. We conclude that CD45 is not required at any stage during the generation of mature peripheral B cells, however its loss reveals a previously unrecognized role for CD45 in the regulation of certain subpopulations of B cells.


2009 ◽  
Vol 23 (20) ◽  
pp. 2376-2381 ◽  
Author(s):  
M. A. Inlay ◽  
D. Bhattacharya ◽  
D. Sahoo ◽  
T. Serwold ◽  
J. Seita ◽  
...  

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3318-3318
Author(s):  
Nahed El Kassar ◽  
Baishakhi Choudhury ◽  
Francis Flomerfelt ◽  
Philip J. Lucas ◽  
Veena Kapoor ◽  
...  

Abstract IL-7 is a non-redundant cytokine in T cell development. We studied the role of IL-7 in early T-cell development using a model of transgenic (Tg) mice with the murine IL-7 gene under control of the lck proximal promoter. At high IL-7 over-expression (x39 fold increase at day 1 in total thymic tissue), we observed a disruption of TCRαβ development along with increased B cell development in the thymus (7- to 13-fold increase) (El Kassar, Blood, 2004). In order to further explore abnormal T and B cell thymic development in these mice, we first confirmed that they both arise in parallel and were non-cell autonomous, by in vivo injection of neutralizing anti-IL-7 MAb and mixed bone marrow chimera experiments. Using a six color flow cytometry analysis, we found a dramatic decrease of the early thymocyte progenitors (ETPs, lin−CD44+CD25−c-kithiIL-7R−/lo) in the adult Tg mice (x4.7 fold decrease). Lin−CD44+CD25−c-kit+ thymocytes were sorted and cultured on OP9 and OP9 delta-like1 (OP9-DL1) stromal cells (kindly provided by Pr Zuniga Pflucker). At day 14, we observed an important decrease of T cell development (54% vs. 1% of DP cells) and an increase of NK cells (x5 fold increase) in the Tg-derived DN1 cell culture. DN2 (Lin−CD44+CD25−c-kit+) Tg thymocytes showed the same, but less dramatic abnormalities. While DN1 progenitors developed effectively into B220+CD19+ cells on OP9 stromal cells, no B cell development was observed on OP-DL stromal cells from DN1-Tg derived progenitors or by addition of increasingly high doses of IL-7 (x10, x40, x160) to normal B6-derived DN1 progenitors. Instead, a block of T-cell development was observed with increased IL-7. We hypothesized a down regulation of Notch signaling by IL-7 over-expression and analyzed by FACS Notch expression in the DN thymocytes. By staining the intra-cellular part of Notch cleaved after Notch 1/Notch ligand activation, Tg-derived DN2 cells showed decreased Notch signaling. More importantly, HES expression was decreased in the DN2, DN3 and DN4 fractions by semi-quantitative PCR. Sorted Pro/Pre B cells from Tg thymi showed TCR Dβ1-Jβ1 rearrangement indicating their T specific origin, in opposition to Pro/Pre B cells sorted from the bone marrow of the same mice. We suggest that more than one immature progenitor seeds the thymus from the bone marrow. While ETPs had T and NK proliferative capacity, another thymic progenitor with B potential may be responsible for thymic B cell development in normal and IL-7 Tg mice. Finally, IL-7 over-expression may induce a decreased Notch signaling in thymic progenitors, inducing a switch of T vs. B lineage development.


Blood ◽  
2000 ◽  
Vol 96 (8) ◽  
pp. 2803-2807 ◽  
Author(s):  
Chaim M. Roifman ◽  
Junyan Zhang ◽  
David Chitayat ◽  
Nigel Sharfe

Abstract Both in vitro and in vivo studies established that interleukin 7 (IL-7) is essential for differentiation of immature T cells and B cells but not natural killer (NK) cells in the mouse. In humans, although both T-cell and B-cell progenitors express the functional IL-7 receptor that consists of IL-7Rα and the γcommon (γc) chain, this lymphocyte receptor system is critical for T lineage but not for B lineage development. Indeed, complete γc deficiency like IL-7Rα deficiency results in the arrest of T-cell but not B-cell development (T−B+ SCID). However, partial deficiency of γc caused by missense mutations results in a T+B+ phenotype and a delay of clinical presentation. It was therefore plausible to assume that partial deficiency of IL-7Rα, like partial γc deficiency may lead to a milder clinical and immunologic phenotype. A P132S mutation in the IL-7Rα was identified in 3 patients with severe combined immunodeficiency (SCID) within an extensively consanguineous family. Substitution of proline with serine in the extracellular portion of IL-7Rα did not affect IL-7Rα messenger RNA (mRNA) and protein expression, but severely compromised affinity to IL-7, resulting in defective signal transduction. In response to IL-7 stimulation, Jak-3 phosphorylation was markedly reduced in both patient cells as well as in COS cells reconstituted with mutant IL-7Rα. Surprisingly, this partial deficiency of IL-7Rα resulted in a severe phenotype, including markedly reduced circulating T cells while sparing B-cell numbers similar to γc chain deficiency. However, unlike the previously reported cases, serum immunoglobulins were virtually absent. Further, unlike γc deficiency, NK cell numbers and function was preserved. Despite the partial deficiency, clinical presentation was indistinguishable from a complete γc deficiency, including severe and persistent viral and protozoal infections and failure to thrive. Unlike partial γc deficiency, a partial deficiency of IL-7Rα results in an arrest of T-cell development, leading to typical severe combined immunodeficiency. This underscores the critical role of IL-7Rα chain in the differentiation of T cells.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 112-112 ◽  
Author(s):  
Natalija Buza-Vidas ◽  
Henrik Ahlenius ◽  
Corrado M. Cilio ◽  
Marcus Svensson ◽  
William Agace ◽  
...  

Abstract We recently demonstrated that signaling through the cytokine tyrosine kinase receptor flt3 and interleukin-7 receptor a (IL-7Ra) is indispensable for fetal and adult B cell commitment and development (Sitnicka et al., J. Exp. Med. 198: 1495, 2003). These receptors are also implicated to be important in regulation of T cell development, but their potential interdependence remains unexplored. We recently showed that flt3 ligand (FL)-deficient mice have reduced levels of early thymic progenitors as well as the common lymphoid progenitor (CLP) (Sitnicka et al., Immunity, 17:463, 2002). In the present study we investigated T cell development in mice deficient in FL and IL-7Ra expression. Strikingly, when compared to FL−/− and IL-7Ra−/− mice, FL−/−xIL-7Ra−/− (double deficient) mice (8-10 week old) lack visible lymph nodes and Peyer’s Patches. Thymic cellularity was dramatically reduced to only 0.3% of FL−/− and wild type (WT) controls and to only 4% of IL-7Ra−/− mice. In agreement with previous studies, IL-7Ra−/− thymocytes revealed a partial block at the progression from the DN2 (CD4−CD8−CD44+CD25+) to DN3 (CD4−CD8−CD44−CD25+) stage, while in FL−/−xIL-7Ra−/− mice DN1 (CD4−CD8−CD44+CD25−), DN2 and DN3 thymic progenitors were undetectable. Thus, severe reductions in early thymocyte development in FL−/−xIL-7Ra−/− mice support a similar role for cross talk between these two signaling pathways in T cell development as recently demonstrated for B cell genesis.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 124-124
Author(s):  
Ivan Maillard ◽  
Laleh Talebian ◽  
Zhe Li ◽  
Yalin Guo ◽  
Daisuke Sugiyama ◽  
...  

Abstract The family of core binding factors includes the DNA-binding subunits Runx1-3 and the common non-DNA binding partner CBFβ. Runx1 and CBFβ are essential for the emergence of hematopoietic stem cells during fetal development, but not for stem cell maintenance during later ontogeny. Runx1 is also required for megakaryocyte differentiation, B cell development, and for the DN2 to DN3 transition in thymocyte development. Runx2/CBFβ are critical for normal osteogenesis, and Runx3 for CD4 silencing in CD8+ T cells, but their contribution to other steps of hematopoietic development is unknown. To examine the collective role of core binding factors in hematopoiesis, we generated a hypomorphic Cbfb allele (Cbfbrss). CBFβ protein levels were reduced by approximately 2–3 fold in fetuses homozygous for the Cbfbrss allele (Cbfbrss/rss), and 3–4 fold in fetuses carrying one hypomorphic and one knockout allele (Cbfbrss/−). Cbfbrss/rss and Cbfbrss/− fetuses had normal erythroid and B cell development, and relatively mild abnormalities in megakaryocyte and granulocyte differentiation. In contrast, T cell development was very sensitive to an incremental reduction of CBFβ levels: mature thymocytes were decreased in Cbfbrss/rss fetuses, and virtually absent in Cbfbrss/−fetuses. We next assessed the development of Cbfbrss/rss and Cbfbrss/− fetal liver progenitors after transplantation to irradiated adult recipients, in competition with wild-type (wt) bone marrow cells. Wt, Cbfbrss/rss and Cbfbrss/− fetal progenitors replenished the erythroid, myeloid and B cell compartments equally well. The overall development of Cbfbrss/rss T cells was preserved, although CD4 expression was derepressed in double negative thymocytes. In Cbfbrss/− chimeras, mature thymocytes were entirely derived from competitor cells. Furthermore, the developmental block in Cbfbrss/− progenitors was present at the earliest stages of T cell development within the DN1 (ETP) and DN2 subsets. Our data define a critical CBFβ threshold for normal T cell development, and they situate an essential role of core binding factors during the earliest stages of T cell development. In addition, early thymopoiesis appeared more severely affected by reduced CBFβ dosage than by the lack of Runx1 (Ichikawa et al., Nat Med 2004; Growney et al., Blood 2005), suggesting that Runx2/3 may contribute to core binding factor activity in the T cell lineage.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3151-3151
Author(s):  
Jalal Taneera ◽  
Emma Smith ◽  
Mikael Sigvardsson ◽  
Emil Hansson ◽  
Urban Lindahl ◽  
...  

Abstract Notch activation has been suggested to promote T cell development at the expense of B cell commitment at the level of a common lymphoid progenitor prior to B cell commitment. Here, we explored the possibility that Notch activation might be able to switch the fate of already committed B cell progenitors towards T cell development upon Notch activation. To address this we overexpressed constitutively activated Notch-3 (N3IC) in B cell progenitors purified from transgenic mice in which human CD25 is expressed under control of the λ5 promoter. Strikingly, whereas untransduced and control transduced B220+λ5+CD3− B cell progenitors gave rise exclusively to B cells, CD4+ and CD8+ T cells but no B cells were derived from N3IC-transduced cells when transplanted into sublethally irradiated NOD-SCID mice. Gene expression profiling demonstrated that untransduced B220+ λ5+CD3− B cell progenitors expressed λ5 and CD19 but not the T cell specific genes GATA-3, lck and pTα, whereas CD3+ T cells derived from N3IC-transduced B220+λ5+CD3−cells failed to express λ5 and CD19, but were positive for GATA-3, lck and pTα expression as well as a and b T cell rearrangement. Furthermore, DJ rearrangements were detected at very low levels in CD3+ cells isolated from normal non-transduced BM, but were more abundant in the N3IC-transduced CD3+ BM cells. Noteworthy, N3IC-transduced B220+λ5+CD3−CD19+ proB cell progenitors failed to generate B as well as T cells, whereas N3IC-transduced B220+λ5+CD3−CD19− pre-proB cells produced exclusively T cells, even when evaluated at low cell numbers. In conclusion Notch activation can switch committed B cell progenitors from a B cell to a T cell fate, but this plasticity is lost at the Pro-B cell stage, upon upregulation of CD19 expression.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2244-2244
Author(s):  
Gerald J. Spangrude ◽  
Birgitta Johnson ◽  
Scott Cho ◽  
Xiaosong Huang ◽  
L. Jeanne Pierce

Abstract The ability to study lymphocyte differentiation in culture has been greatly advanced by the availability of the OP9 bone marrow stromal cell line, which was derived from an op/op mouse and thus lacks M-CSF. As a result, the normal default myeloid differentiation from bone marrow-derived stem and progenitor cells does not occur, and lymphocyte differentiation is favored. Introduction of the Notch ligand Delta-like 1 into OP9 cells results in promotion of T cell development and parallel suppression of B cell development. While the OP9-DL1 model of T cell development works quite well when fetal liver-derived progenitors are cultured, the success of T cell development from adult bone marrow-derived progenitors has been more difficult to reproduce. We have undertaken a systematic analysis of variables that can prevent efficient T cell development in OP9-DL1 cultures, and have found that one limiting factor that impacts the efficiency of differentiation of both T and B cell lineages is the accumulation of ammonium ions as a result of the spontaneous decomposition of l-glutamine. L-glutamine, which is present at 2 to 4 mM in standard tissue culture media, is unstable and will spontaneously degrade to form ammonium ions and pyroglutamic acid at a rate of 1%/day at 4°C and at a 10-fold higher rate at 37°C. To evaluate the effects of the two major products of l-glutamine decomposition on lymphoid differentiation, we added each product to differentiation cultures at 3 mM in the presence of a stable source of l-glutamine (l-alanyl-l-glutamine). Cultures were established in 1 ml containing 4×104 stromal cells (OP9 for B cell differentiation, OP9-DL1 for T cell differentiation), 1×103 bone marrow-derived lymphoid progenitors enriched by phenotype (c-kit+LinnegSca-1+Thy-1.1neg), and 5 ng/ml Flt3L plus 5 ng/ml IL-7. Every 3 to 4 days, cultures were harvested and passaged onto fresh stromal cell monolayers; lymphoid cells were counted and evaluated for surface antigen expression at each passage. While addition of pyroglutamic acid had no inhibitory effect on lymphocyte growth or differentiation, addition of ammonium chloride slowed growth and prevented differentiation of both T and B lymphocytes. Growth of the stromal cell monolayers was not affected by ammonium chloride at the concentrations utilized in these studies. We conclude that freshly-prepared culture medium, preferably containing a stabilized form of l-glutamine, is a critical aspect contributing to the success of lymphocyte differentiation cultures established from adult bone marrow cells. We also found that decreasing IL-7 concentrations to 1 ng/ml resulted in more rapid differentiation of T cells and a more balanced representation of CD4 and CD8 single positive cells. Our studies help define optimal conditions for differentiation of bone marrow-derived lymphoid progenitor cells into T and B lineages in vitro, and provide evidence that hematopoietic differentiation displays variable degrees of sensitivity to ammonium ions derived from decomposition of l-glutamine. These results will help define optimal conditions for expansion and differentiation of hematopoietic stem and progenitor cells in vitro.


1997 ◽  
Vol 155 (1) ◽  
pp. 165-170 ◽  
Author(s):  
R Kooijman ◽  
SC van Buul-Offers ◽  
LE Scholtens ◽  
RG Reijnen-Gresnigt ◽  
BJ Zegers

Treatment of mice with IGF-I stimulates T and B cell development. We showed that overexpression of IGF-II in transgenic FVB/N mice only stimulated T cell development. In the present study, we further addressed the in vivo effects of IGF-II in the absence of IGF-I to get more insight into the potential abilities of IGF-II to influence T and B cell development. To this end, we studied lymphocyte development in IGF-II transgenic Snell dwarf mice that are prolactin, GH and thyroid-stimulating hormone deficient and as a consequence show low serum IGF-I levels. We showed that T cell development was stimulated to the same extent as in IGF-II transgenic FVB/N mice. Furthermore, IGF-II increased the number of nucleated bone marrow cells and the number of immature B cells without having an effect on the number of mature B cells in spleen and bone marrow. Our data show that IGF-II has preferential effects on T cell development compared with B development, and that these preferential effects also occur in the absence of measurable IGF-I levels.


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