Regeneration of autotransplanted splenic tissue at different implantation sites

Abstract

Inbred animals (Lewis rats) were used to investigate the regeneration of autologously implanted splenic tissue at intra-omental and subcutaneous sites. Quantitative immunohistology with monoclonal antibodies against lymphocytes and macrophages was performed to analyse the cell density of red pulp (RP), periarteriolar lymphoid sheath (PALS), marginal zone (MZ) and follicle, 7-180 days after transplantation. Antigenic, allogeneic and mitogenic stimulation and Northern blotting were also performed. Transplant groups differed from spleen only in the reduced size of PALS; however, quantitative analysis demonstrated subtle differences between spleen and transplants. The cell density of B-cells and ED-1+ macrophages was reduced in the RP, Tsupp/cyt-cells were decreased and B-cells increased in PALS, and B-cells and Thelper-cells reduced in the MZ. No differences could be detected between the transplant groups. Flow-cytometric analysis of cell suspensions from spleen and transplants revealed a reduction of T-cells (OX-19+), MHC-I and transferrin-receptor-bearing cells in both transplant groups, and a decrease in the number of Thelper-cells and ED-3+ macrophages in subcutaneous transplants. Both transplant groups were defective regarding the allogeneic and pokeweed mitogen response. Aberration of the lipopolysaccharide response was restricted to subcutaneous transplants, which additionally showed abnormal expression of interferon-gamma, interleukin-5 and interleukin-6 mRNA. Thus, subtle alterations of the newly developed microenvironment and/or lymphocyte-homing may influence the regeneration of splenic tissue; the implantation site may represent an important parameter in functional reorganisation.

Antibody Response of Autogenous Splenic Tissue Implanted in the Abdominal Cavity of Mice

“…Our data are in accord with studies in which normal numbers of IgM PFCs were detected 3 to 4 months after splenic implantation in both omental and subcutaneous transplants in rats 19 . Consistent with this assumption, a restored serum antibody response to intravenous challenge with SRBCs was described after intraperitoneal and subcutaneous splenic autotransplantation, with no rise in the asplenic animals 27 .…”

“…We cannot formally exclude the possibility that the suture thread used for the intraomental implants contributed to the complications in this scenario. Furthermore, in the case of the omentum autotransplant site, torsion of the omentum has been described as a cause of acute abdomen 11,19 and aseptic necrosis of the graft 29 . We suspect that the same type of adhesions observed in our model could occur in humans.…”

“…12,17 However, there have been complications associated with intraomental splenic autotransplantation, such as torsion of the implant, anemia, and subphrenic abscesses due to necrosis of the implanted tissue. 2,19 Although many studies have attempted to elucidate the immunologic function of autotransplanted splenic tissue, a general consensus has not been achieved.…”

Plasma Lipid Levels of Rats Fed a Diet Containing Pork Fat as a Source of Lipids after Splenic Surgery

“…A variety of studies have confirmed morphological regeneration of autotransplanted splenic tissue [32][33][34][35]. However, splenic regeneration does not necessarily mean recovery of organ function.…”

Splenic autotransplantation reverses interferon‐gamma and nitric oxide production and resistance to Listeria monocytogenes in splenectomized mice

“…Various implantation sites have been described, including subcutaneous tissue, the retroperitoneum, muscles of the abdomen, and the greater omentum. The greater omentum implantation site is the most widely used and also the most recognized in the literature (9). No significant differences have been found between the splenic implants located in the greater omentum and other intraperitoneal sites regarding their morphology and capacity to produce antibodies (5).…”