The effect of early thymectomy on histogenesis of the lymphoid organs in Xenopus laevis

Development ◽  
1971 ◽  
Vol 26 (2) ◽  
pp. 219-229
Author(s):  
Margaret J. Manning
Keyword(s):  
Xenopus Laevis ◽  
Lymphoid Organs ◽  
White Pulp ◽  
Normal Complement ◽  
Splenic White Pulp ◽  
The Difference ◽  
Immature Cells ◽  
Splenic Red Pulp ◽  
Red Pulp

The role of the thymus in the ontogenetic development of the lymphoid system of the clawed toad, Xenopus laevis, was investigated by removing the organ at stage 49 of Nieuwkoop & Faber (1967), a stage when small lymphocytes are present in the thymus but have not yet appeared in the peripheral lymphoid organs. Complete thymectomy, confirmed histologically, was achieved in nine larvae killed at stage 56 and in 23 larvae killed at stage 59. The spleen was smaller in thymectomized larvae than in sham-thymectomized controls in the series killed at stage 56, but the difference was no longer significant at stage 59. In both series, thymectomized larvae showed a fall in the number of extra-follicular lymphocytes and an increase in the reticulo-myeloid elements of the splenic red pulp. The pharyngeal ventral cavity bodies were moderately or severely depleted of lymphocytes. In other areas, histogenesis proceeded normally in the absence of the thymus. In the splenic white pulp, the follicles, which comprised immature cells of the lymphoblast type at the time of thymectomy, developed their normal complement of lymphocytes. All larvae grew and developed at the normal rate.

scholarly journals Studies on Regeneration of Heterotopic Splenic Autotransplants

Blood ◽  
1973 ◽  
Vol 41 (5) ◽  
pp. 701-709 ◽  
Author(s):  
Mehdi Tavassoli ◽  
R. Judith Ratzan ◽  
William H. Crosby
Keyword(s):  
Blood Cells ◽  
Subcutaneous Tissue ◽  
Regenerative Process ◽  
Splenic Tissue ◽  
White Pulp ◽  
Microscopic Structure ◽  
Small Arteries ◽  
Splenic White Pulp ◽  
Splenic Red Pulp ◽  
Red Pulp

Abstract Fragments of spleen autotransplanted to subcutaneous tissue of the abdomen in the rat undergo almost complete necrosis and then regenerate into splenic tissue with a microscopic structure indistinguishable from the structure of the original organ. The regenerative process reminiscent of the spleen’s embryogenesis, originates from a shell of surviving splenic tissue at the surface of the implant. The regenerative zone first consists of almost monotonous connective tissue cells interspersed with red blood cells; it develops into splenic red pulp consisting of sinuses and intersinal cords. As capillaries develop, the structure of small arteries and peri-arterial lymphatic sheaths appear, and soon the structure of splenic white pulp becomes evident. Some 5 wk after autotransplantation, the splenic reconstruction is complete. The weight of the recovered tissue is a linear function of the weight of the implanted tissue; yet the linearity is lost when the weight of the implanted tissue exceeds 100 mg.

scholarly journals Reticular fibroblasts in peripheral lymphoid organs identified by a monoclonal antibody.

1986 ◽  
Vol 34 (7) ◽  
pp. 883-890 ◽  
Author(s):  
E Van Vliet ◽  
M Melis ◽  
J M Foidart ◽  
W Van Ewijk
Keyword(s):  
Marginal Zone ◽  
Lymphoid Organs ◽  
White Pulp ◽  
Sulfate Proteoglycan ◽  
Cellular Organization ◽  
Frozen Sections ◽  
Collagen Types ◽  
Medullary Cords ◽  
Red Pulp

We have produced a panel of monoclonal antibodies directed against nonlymphoid cells in central and peripheral lymphoid organs. In this paper we present the reactivity of one of these antibodies, ER-TR7. This antibody detects reticular fibroblasts, which constitute the cellular framework of lymphoid and nonlymphoid organs and their products. In frozen sections of the spleen incubated with this antibody, the red pulp and white pulp are clearly delineated. Furthermore, the major white pulp compartments--the follicles and periarteriolar lymphoid sheath as well as the marginal zone--are recognized by their characteristic labeling patterns. In lymph nodes, the capsule, sinuses, follicles, paracortex, and medullary cords are clearly delineated. In the thymus and bone marrow no such specialized compartments were demonstrated. ER-TR7 reacts with an intracellular component of fibroblasts. Since ER-TR7 does not react with purified laminin, collagen types I-V, fibronectin, heparan sulfate proteoglycan, entactin, or nidogen, it detects a hitherto uncharacterized antigen. The possible role of the ER-TR7 positive reticular fibroblasts in the cellular organization of peripheral lymphoid organs will be discussed.

scholarly journals The Action of Phytohemagglutinin in Rabbits. V. Morphological Changes Following Previous Immunization with and Daily Injections of Phytohemagglutinin

Blood ◽  
1969 ◽  
Vol 33 (5) ◽  
pp. 727-738
Author(s):  
J. B. BLENNERHASSETT ◽  
C. K. NASPITZ ◽  
M. RICHTER
Keyword(s):  
Chemotherapeutic Agent ◽  
Single Injection ◽  
Morphological Changes ◽  
White Pulp ◽  
Myeloid Metaplasia ◽  
Splenic White Pulp ◽  
Circulating Antibodies ◽  
Splenic Red Pulp ◽  
Morphologic Changes ◽  
Red Pulp

Abstract The administration of a series of four or eight daily injections of PHA neither diminished nor enhanced the peripheral and parenchymal changes observed after a single injection of PHA. These changes include the peripheral leukopenia followed by a leukocytosis, the hyperplasia of the splenic white pulp, and the myeloid metaplasia or infiltration in the splenic red pulp. The circulating leukocytes appear to become resistant to the leukopenic action of PHA following a series of injections of PHA. However, this stage of refractoriness lasts only one to two weeks in the absence of any further injection of PHA. Immunization with PHA with formation of antibodies capable of neutralizing the mitogenic factor(s) in PHA did not affect the capacity of a subsequent challenge injection of PHA to induce the characteristic morphologic changes which follow a single injection of PHA. Thus, the presence of circulating antibodies does not invalidate the use of PHA as a chemotherapeutic agent.

scholarly journals Morphometric and Histopathologic Analysis of Lymphoid Depletion in Murine Spleens Following Infection with Brucella abortus strains 2308 or RB51 or an htrA Deletion Mutant

1996 ◽  
Vol 33 (3) ◽  
pp. 282-289 ◽  
Author(s):  
M. V. Palmer ◽  
N. F. Cheville ◽  
F. M. Tatum
Keyword(s):  
Morphometric Analysis ◽  
Brucella Abortus ◽  
Marginal Zone ◽  
White Pulp ◽  
Splenic White Pulp ◽  
Lymphoid Depletion ◽  
Histopathologic Changes ◽  
Histopathologic Analysis ◽  
Marginal Zones

BALB/C mice were inoculated intraperitoneally with suspensions of Brucella abortus strains 2308 or RB51 or an htrA mutant. Spleens were examined on postinoculation day (PID) 2, 4, 7, 10, 15, 21, 30, and 60. Brucellae were cultured in high numbers from the spleens of mice infected with strains 2308 or htrA through PID 60; however, mice infected with strain RB51 cleared the infection between PID 30 and PID 60. Histopathologic changes in spleens from 2308-infected mice were characterized by marked accumulations of macrophages, which expanded marginal zones beginning as early as PID 7 and persisting through PID 60. Morphometric analysis showed a decrease in splenic white pulp in 2308-infected mice at PID 10, which correlated with the peak of bacterial infection. Although this decrease was significant ( P < 0.05) when compared with values at the previous (PID 7) and the following (PID 15) time periods, it was not significantly different from white pulp values noted at PID 2 or PID 4 or the values for control spleens. Spleens from RB51-infected mice showed only mild to moderate accumulations of macrophages in marginal zone areas during the peak of RB51 infection (PID 7-10). Morphometric analysis of RB51-infected spleens showed a decrease in white pulp area, which coincided with peak bacterial numbers. However, this decrease was not significant ( P > 0.05). Spleens from mice infected with the htrA mutant showed moderate to marked accumulations of macrophages in marginal zone areas, which persisted through PID 60. Multifocal necrosis in lymphoid follicles as early as PID 4 was seen in both htrA and 2308 infection. Morphometric analysis of htrA-infected spleens revealed no significant decrease in white pulp and no obvious correlation with bacterial numbers in the spleen. These results suggest that virulent B. abortus does not induce lymphoid depletion significantly below those values seen in noninfected mice; thus, the possible role of lymphoid depletion in the pathogenesis of brucellosis remains questionable.

The role of water-regulating mechanisms in the development of the haploid syndrome in Xenopus laevis

Development ◽  
1972 ◽  
Vol 28 (2) ◽  
pp. 449-462
Author(s):  
Louie Hamilton ◽  
P. H. Tuft
Keyword(s):  
Xenopus Laevis ◽  
Cell Number ◽  
Gastrula Stage ◽  
Tail Bud ◽  
Volume Changes ◽  
Membrane Area ◽  
Flow Through ◽  
The Difference ◽  
Haploid Embryos

The uptake of water by haploid and diploid sibling embryos of Xenopus laevis has been investigated by measuring the density changes which occur during the development of intact embryos from the blastula to the late tail-bud stage, and of explants from which most of the presumptive endoderm has been removed. The results show that up to the mid-gastrula stage there is no difference between the haploid and diploid embryos; but from then on, whereas the diploid volume increases steadily, the haploid gastrulae undergo a series of cyclical volume changes due to loss of fluid through the blastopore. It is concluded that this is the result of an excessive inflow of water through the haploid ectoderm, because it was found that the volume of haploid ectodermal explants increased much more rapidly than the volume of similar diploid explants. Excess flow through the haploid ectoderm also accounts for other characteristics of the haploid syndrome – microcephaly and lordosis. It is suggested that it is the doubling of the cell number in haploid embryos with the consequent 25% increase in aggregate cell membrane area which accounts for the difference between the uptake of water by the two types of embryos. It is also suggested that changes in the rate of water flow through the ectoderm and endoderm which are thought to account for the accumulation of water in the blastocoel and archenteron in the normal diploid embryo arise in a similar way.

scholarly journals Cyclical modulation of sphingosine-1-phosphate receptor 1 surface expression during lymphocyte recirculation and relationship to lymphoid organ transit

2005 ◽  
Vol 201 (2) ◽  
pp. 291-301 ◽  
Author(s):  
Charles G. Lo ◽  
Ying Xu ◽  
Richard L. Proia ◽  
Jason G. Cyster
Keyword(s):  
Lymph Nodes ◽  
Surface Expression ◽  
Lymphoid Organ ◽  
Lymphoid Organs ◽  
White Pulp ◽  
Activated T Cells ◽  
Circulating Lymphocytes ◽  
Sphingosine 1 Phosphate ◽  
Splenic White Pulp ◽  
Lymphocyte Egress

Sphingosine-1-phosphate receptor 1 (S1P1) was recently shown to be required for lymphocyte egress from lymphoid organs. Here we have examined the relationship between S1P1 abundance on the cell and egress efficiency. Using an integrin neutralization approach to separate the processes of entry and exit, we show that pertussis toxin treatment reduces lymphocyte egress from lymph nodes. Retrovirally mediated S1P1 overexpression is sufficient to reduce B cell accumulation in the splenic white pulp and to promote egress of activated T cells from lymph nodes, whereas S1P1+/−cells have reduced lymph node exit efficiency. Furthermore, lymphocyte S1P1 is down-regulated in the blood, up-regulated in lymphoid organs, and down-regulated again in the lymph. We propose that cyclical ligand-induced modulation of S1P1 on circulating lymphocytes contributes to establishing their lymphoid organ transit time.

scholarly journals Crucial Role of Tumor Necrosis Factor Receptor 1 Expression on Nonhematopoietic Cells for B Cell Localization within the Splenic White Pulp

1998 ◽  
Vol 187 (4) ◽  
pp. 469-477 ◽  
Author(s):  
Maria Tkachuk ◽  
Stephan Bolliger ◽  
Bernhard Ryffel ◽  
Gerd Pluschke ◽  
Theresa A. Banks ◽  
...  
Keyword(s):  
B Cells ◽  
Tumor Necrosis ◽  
Plasma Cells ◽  
Tumor Necrosis Factor Receptor ◽  
White Pulp ◽  
Splenic White Pulp ◽  
Initial Activation ◽  
Deficient Mice ◽  
Necrosis Factor

During immune responses the initial activation of B cells takes place in T cell zones of periarteriolar lymphoid sheaths (PALS) of the splenic white pulp. After initial activation, B cells migrate into the primary follicles and, in association with follicular dendritic cells (FDCs), undergo clonal expansion and differentiation giving rise to germinal centers (GCs). Peanut agglutinin binding (PNA+) cells of the GC differentiate further into memory or plasma cells. Here we report that in tumor necrosis factor receptor 1–deficient mice (TNFR1−/−), the location of B cells was altered and that plasma cells were abnormally distributed in the splenic PALS. In contrast to lymphotoxin α–deficient mice (LTα−/−), bone marrow or fetal liver transplantation did not correct the abnormal organization of the spleen, location of B cells, the lack of an FDC network, nor the antibody response in TNFR1−/− mice. These results argue for a crucial role of TNFR1 expression on nonhematopoietic cells for the maintenance of the splenic architecture and proper B cell location. In addition, the lack in development of an FDC network after adoptive transfer suggests that either FDCs are not of bone marrow origin or that they depend on signals from nonhematopoietic cells for maturation.

Clever-1 contributes to lymphocyte entry into the spleen via the red pulp

2019 ◽  
Vol 4 (33) ◽  
pp. eaat0297 ◽  
Author(s):  
Sina Tadayon ◽  
Johannes Dunkel ◽  
Akira Takeda ◽  
Olga Halle ◽  
Marika Karikoski ◽  
...  
Keyword(s):  
B Cell ◽  
Molecular Mechanisms ◽  
Ex Vivo ◽  
Critical Role ◽  
Lymphoid Organs ◽  
White Pulp ◽  
Cell Trafficking ◽  
Genetic Ablation ◽  
Regulated Trafficking ◽  
Red Pulp

Lymphocytes recirculate continuously between the blood and lymphoid organs, a process that is of fundamental importance for proper functioning of the immune system. The molecular mechanisms underlying lymphocyte trafficking to the spleen remain an enigma. Here, we show that lymphocytes enter the spleen preferentially from vessels in the red pulp rather than the marginal sinus or the vasculature in the white pulp. Ex vivo adhesion assays in mice and humans, together with genetic ablation of Clever-1 in mice, indicate that CD8+T cell and B220+B cell homing to the spleen via the red pulp is Clever-1 dependent. Moreover, absence of Clever-1 leads to down-regulation of the B cell attractant chemokine, CXCL13, on spleen endothelium. CXCL13 is known to guide B cell trafficking to lymphoid organs, and its lack may contribute to the observed decrease in B cell trafficking into the spleen as well. In summary, this study identifies Clever-1 as an important molecule controlling lymphocyte entry into the spleen, along with a critical role for the splenic red pulp in this regulated trafficking. Furthermore, the results demonstrate that location-specific homing-associated molecules guide lymphocyte entry into the spleen.

The developmental endocrinology of the spleen in chick embryos

Development ◽  
1970 ◽  
Vol 24 (2) ◽  
pp. 357-365
Author(s):  
T. W. Betz
Keyword(s):  
Chick Embryo ◽  
Growth And Development ◽  
White Pulp ◽  
Chick Embryos ◽  
Pars Distalis ◽  
Liver Growth ◽  
Body Weights ◽  
Pars Nervosa ◽  
Splenic White Pulp ◽  
Red Pulp

Partial decapitation (‘hypophysectomy’) of the chick embryo significantly reduces body growth by 20 days (stage 46 −) of incubation as indicated by body weights, 60% of normal; the lengths of the toe and tibiotarsus, 80% and 78% of normal respectively; and liver growth, 47% of normal, but the gall bladder was not apparently enlarged. It significantly increases spleen growth to 82 % greater than normal, suppresses or retards white pulp differentiation and splenic vasculogenesis but enhances red pulp development. A single pars distalis gland placed as a chorioallantoic graft into operated embryos prevents the development of these defects except for liver growth which, while improved, is still subnormal. If the number of grafts is increased by one or two there is no change in the amount of influence on growth and development of the chick embryo. This apparent regulation occurs by some unknown mechanism even in the absence of the hypothalamus. Thus body and liver growth is normally stimulated by the pars distalis but spleen growth and red pulp differentiation are suppressed even though the gland stimulates splenic white pulp histogenesis. The hypothalamus, epiphysis and pars nervosa (removed by partial decapitation) are not apparently involved in the developmental endocrinology of the spleen in chick embryos.

scholarly journals A A STUDY OF HISTOLOGY & HISTOGENESIS OF FETAL SPLEEN AT DIFFERENT GESTATIONAL AGES

2019 ◽  
Vol 3 (12) ◽  
Author(s):  
Srivani D ◽  
J. Jayachandra Pillai
Keyword(s):  
Lymphoid Tissue ◽  
Histological Analysis ◽  
White Pulp ◽  
Detailed Knowledge ◽  
Morphometric Features ◽  
Fetal Hematopoiesis ◽  
Fetal Wellbeing ◽  
Haematoxylin And Eosin Stain ◽  
Red Pulp

Introduction: The spleen is a largest collection of lymphoid tissue with peculiar anatomical and physiological features. Spleen plays an important role in fetal hematopoiesis and immunomodulation. The aim of the study is to perform detailed histological analysis of human fetal splenic specimens of various gestational ages  and compare the findings with earlier studies. Material and  Methods:  The  present  study  included  40  fetal cadaveric spleen and  morphometric features i.e., weight was measured and the sections of the spleen were stained  with Haematoxylin and Eosin stain and were observed under compound light microscope Results: In the present study the histology of spleens of prenatal group showed the well defined red pulp, venous sinusoids and diffusely spread lymphocytes at 18 weeks of gestation and the organization of lymphoid follicles was noticed at 24-28 weeks. At 32 weeks well defined white pulp was observed and the microscopic architecture of the spleen was similar to the histology of adult spleen. Conclusion: A detailed knowledge of splenic morphometric dimensions, Histology and Histogenesis is crucial in deciphering the role of spleen in fetal development and fetal wellbeing. Key words: spleen, hematopoietic, microscopic,  fetal

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