Enhanced Regeneration of Transplanted Splenic Tissue by Increased Work Load to the Splenic Compartments

Pabst, Reinhard; Hafke, Robert; Hillebrand, J.

doi:10.1097/00005373-198504000-00008

Cited by 16 publications

(7 citation statements)

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“…200 g of about 3 months of age were used for all experiments. Sham operation (n 10), splenectomy (n 10) and splenic autotransplantation (n 10) were performed as described by Pabst et al [14]. In short, all operations were performed via an upper midline incision, under ether anaesthesia and clean but not sterile conditions.…”

Section: Introductionmentioning

confidence: 99%

Spleen autotransplantation provides restoration of functional splenic lymphoid compartments and improves the humoral immune response to pneumococcal polysaccharide vaccine

Leemans

Harms

Rijkers

et al. 1999

Clinical and Experimental Immunology

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After splenectomy, patients have an increased risk of overwhelming post-splenectomy infection (OPSI) or sepsis involving encapsulated bacteria such as pneumococcus. The value of spleen autotransplantation after splenectomy because of trauma has long been questioned. Much attention has been given to the restoration of mononuclear phagocyte system (MPS) function, which appeared to be similar to that of splenectomized individuals. The presence of specific anti-pneumococcal antibodies may enhance phagocytosis of opsonized bacteria by other parts of the MPS, as present in the liver. Therefore, in the present study we have evaluated the restoration of the humoral immune response after spleen autotransplantation, especially to pneumococcal capsular polysaccharides (PPS). Wistar rats were divided into three groups which were operated as follows: splenectomy, splenectomy followed by autotransplantation, and sham operation. After 12 weeks the rats were vaccinated with 23-valent pneumococcal vaccine. Blood samples were taken after 3 days, 3 and 6 weeks for anti-PPS IgM and IgG ELISA against types 3, 4, 6, 9, 14 and 23. In addition, immunohistological studies were performed on the autotransplants. Significant antibody titre rises were found in a main proportion of the autotransplanted rats, comparable to sham-operated rats. Splenectomized rats showed as well a significantly lower increase in immunoglobulin levels, as significant differences in the proportion of rats showing a minimum two-fold increase of antibody level, considered to represent an adequate response. The titres were highest 3 days after vaccination. Immunohistochemical studies demonstrated structurally functional autotransplants, including an intact marginal zone. Considering this significant anti- pneumococcal antibody response, spleen autotransplants can be expected to enable an improved humoral response to PPS, and to contribute to protection against OPSI after splenectomy.

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Section: Introductionmentioning

confidence: 99%

Spleen autotransplantation provides restoration of functional splenic lymphoid compartments and improves the humoral immune response to pneumococcal polysaccharide vaccine

Leemans

Harms

Rijkers

et al. 1999

Clinical and Experimental Immunology

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“…sterile, conditions (27). At time zero and 28 days later, both the splenectomized rats and control rats were immunized with one of the vaccines described below.…”

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confidence: 99%

Pneumococcal Conjugate Vaccines Overcome Splenic Dependency of Antibody Response to Pneumococcal Polysaccharides

Breukels

Zandvoort²,

Dobbelsteen

et al. 2001

Infect Immun

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Protection against infections with Streptococcus pneumoniae depends on the presence of antibodies against capsular polysaccharides that facilitate phagocytosis. Asplenic patients are at increased risk for pneumococcal infections, since both phagocytosis and the initiation of the antibody response to polysaccharides take place in the spleen. Therefore, vaccination with pneumococcal polysaccharide vaccines is recommended prior to splenectomy, which, as in the case of trauma, is not always feasible. We show that in rats, vaccination with a pneumococcal conjugate vaccine can induce good antibody responses even after splenectomy, particularly after a second dose. The spleen remains necessary for a fast, primary response to (blood-borne) polysaccharides, even when they are presented in a conjugated form. Coadministration of a conjugate vaccine with additional nonconjugated polysaccharides of other serotypes did not improve the response to the nonconjugated polysaccharides. We conclude that pneumococcal conjugate vaccines can be of value in protecting asplenic or hyposplenic patients against pneumococcal infections.Protection against infections with encapsulated bacteria such as Streptococcus pneumoniae depends on the presence of antibodies against capsular polysaccharides. These serotypespecific antibodies facilitate phagocytosis, the main mode of host defense against S. pneumoniae. The spleen is an important organ in the immune response to S. pneumoniae, since it contains both antibody-producing B cells and phagocytes (4, 26). Asplenic patients are therefore at increased risk for invasive infections with S. pneumoniae (13). Although most infections occur within the first few years after splenectomy, the risk of overwhelming postsplenectomy infections is lifelong (9, 36). Therefore, vaccination against S. pneumoniae is indicated for this group. At present, the vaccine available for this aim is the 23-valent pneumococcal polysaccharide (PPS) vaccine (1). The immunogenicity of PPS vaccine in splenectomized patients has been assessed in a number of trials. Some studies have shown the effectiveness of vaccination in inducing protective concentrations of specific antibodies (5, 10, 24, 33), while others have shown limited serological responses (15). As the initiation of the antibody response to polysaccharides seems to depend on the presence of splenic tissue, and in particular on a functional marginal-zone B-cell compartment (3,14,18,34), it may be expected that polysaccharide vaccines are of limited use in asplenic patients.The physical coupling of a polysaccharide to a carrier protein greatly improves the immunogenicity of the polysaccharide, a principle first described in 1929 (11). Conjugated polysaccharides overcome the antipolysaccharide unresponsiveness in early life (2, 8), which is thought to be due to a still immature splenic marginal-zone B-cell compartment (2). The induction of antipolysaccharide antibodies by conjugate vaccines at a young age suggests that conjugates might initiate the antipolysaccharide anti...

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“…and 2) why are there differences in the development of red and white pulp among autografts? Pabst et al (1985) succeeded in increasing the autograft size by stimulating the white pulp by injecting xeno-erythrocytes and the red pulp by injecting phenylhydrazine, suggesting that a continuous work load on the graft may stimulate it to gradually grow.…”

Section: Discussionmentioning

confidence: 99%

Experimental splenosis in the liver and lung spread through the vasculature

et al. 2014

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To demonstrate that intra-organ splenosis can engraft and develop after being distributed through the vasculature, tiny fragments of splenic tissues were injected into the inferior vena cava or the portal vein to induce intrapulmonary and intrahepatic splenosis in rats. After 1 month, splenic autograft structures in the lung and liver were assessed for structure by histology, for immunologic compartments by immunohistochemistry, for phagocytic function by carbon uptake and for vascular formation by Microfil (a silicon rubber compound) injection. Intrapulmonary and intrahepatic splenoses were indeed able to spread through the vasculature. The intrapulmonary splenic autografts were trapped and spread out in the interstitium, without forming a capsule. White pulp was markedly developed, showing lymphocyte aggregations that consisted in B cells surrounding the dilated vessel. Splenic sinuses were not definitively observed. Although macrophages were detected by immunohistochemistry, they showed no indication of having phagocytized carbon particles from the vessels, implying a closed circulation. In contrast, intrahepatic splenic autografts formed well-developed capsules, trabeculae and red pulp with splenic sinuses. Macrophages detected by immunohistochemistry were observed capturing carbon particles, which clearly revealed an open system circulation, as seen in normal rat spleen. The development of white pulp was poor and lymphocytes consisting in B cells aggregated in the peripheral margins. These results demonstrate that intra-organ splenosis can spread through the vasculature and that the morphologic and immunologic structures formed in these regenerated autografts are influenced by the organ vasculature and extracellular matrix wherein the tissue fragments settled.

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Enhanced Regeneration of Transplanted Splenic Tissue by Increased Work Load to the Splenic Compartments

Cited by 16 publications

References 0 publications

Spleen autotransplantation provides restoration of functional splenic lymphoid compartments and improves the humoral immune response to pneumococcal polysaccharide vaccine

Spleen autotransplantation provides restoration of functional splenic lymphoid compartments and improves the humoral immune response to pneumococcal polysaccharide vaccine

Pneumococcal Conjugate Vaccines Overcome Splenic Dependency of Antibody Response to Pneumococcal Polysaccharides

Experimental splenosis in the liver and lung spread through the vasculature

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