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(The FASEB Journal. 1998;12:939-947.)
© 1998 FASEB

RESEARCH COMMUNICATION

Intrahepatic proliferation of `naive' and `memory' T cells during liver allograft rejection: primary immune response within the allograft

Matthias M. Dollingera,1, Sarah E. M. howiea, John N. Plevrisb, Alexandra M. Grahama, Peter C. Hayesb, and David J. Harrisona

a Department of Pathology, Medical School, University of Edinburgh, Edinburgh, EH8 9AG, Scotland, United Kingdom
b Liver Unit, Department of Medicine, The Royal Infirmary, University of Edinburgh, Edinburgh, EH3 9YW, Scotland, United Kingdom


   ABSTRACT
TOP
 ABSTRACT
INTRODUCTION
 EXPERIMENTAL PROCEDURES
 RESULTS
 DISCUSSION
 REFERENCES
 
Liver allograft rejection is mediated by a primary response of T lymphocytes, followed by infiltration of the graft with a mixed inflammatory reaction. Using single and double label immunocytochemistry, we examined the proliferation index and the phenotype of leukocytes on liver biopsies from 10 patients with acute rejection before and after treatment with i.v. steroids, 10 patients with chronic rejection, 10 patients without rejection posttransplant, and 15 nongrafted, nonimmunosuppressed patients. Proliferation of mononuclear leukocytes (assessed by expression of Ki-67, a nuclear antigen associated with the cell cycle) inside the allograft was a prominent feature of acute and chronic rejection and was down-regulated by steroid treatment. Leukocytes in cell cycle were located predominantly in the portal tracts at the site of the inflammatory infiltrate. The majority of `naive' (CD45RA+) and `memory' (CD45RO+) CD4+ T lymphocytes were also periportally distributed. In contrast, CD8+ T lymphocytes, CD57+ natural killer cells, and CD68+ macrophages were located intraparenchymally throughout the liver lobules, whereas CD20+ B lymphocytes were only present in some of the portal tracts. Predominantly CD4+ and occasionally CD8+ lymphocytes were proliferating (assessed by double staining). The proliferating CD4+ cells were of both naive (CD4+, CD45RA+) and memory (CD4+, CD45RO+) phenotypes. To our knowledge, this is the first description of proliferating naive T lymphocytes in situ in liver allografts. These findings suggest that there may be a primary immune response generated within the allograft as well as in draining lymphatic tissue. This implicates not only intrahepatic proliferation of T lymphocytes as a prominent feature of rejection, but also suggests that the liver has a special immunological status comparable to that of lymphatic tissue.—Dollinger, M. M., Howie, S. E. M., Plevris, J. N., Graham, A. M., Hayes, P. C., Harrison, D. J. Intrahepatic proliferation of naive and memory T cells during liver allograft rejection: primary immune response within the allograft. FASEB J. 12, 939–947 (1998)


Key Words: T lymphocytes • liver allograft rejection • transplantation • leukocyte


   INTRODUCTION
TOP
 ABSTRACT
 INTRODUCTION
EXPERIMENTAL PROCEDURES
 RESULTS
 DISCUSSION
 REFERENCES
 
DESPITE IMPROVEMENTS in immunosuppressive therapy, allograft rejection after organ transplantation remains a major clinical challenge. In liver transplant recipients, acute cellular rejection occurs in up to 80% of patients and is associated with increased morbidity and length of hospitalization (1). Chronic rejection is commonly resistant to therapy and leads to the loss of up to 15% of grafts (2). In common with the concept of allograft rejection of other solid organs, rejection of the liver seems to be mediated by T lymphocytes in response to alloantigens (3). The primary immune response involves antigen-presenting cells activating `naive' T lymphocytes, which subsequently start to proliferate and differentiate. According to new research into T cell migration, this primary activation should evolve within lymphatic tissue, since naive T cells appear to recirculate only through lymphatic tissue (4) and lack sufficient levels of surface integrins for transendothelial migration (5). In contrast, the effector mechanism of the response consists of infiltration of the graft, with a mixed inflammatory reaction including predominantly CD4+ and CD8+ lymphocytes together with NK (natural killer)2 cells, macrophages, and neutrophils (6).

Compared with other solid organs, however, the liver appears to be immunologically privileged after transplantation. In clinical practice, liver allografts are more resistant to rejection than other organs despite lower levels of immunosuppression, and human leukocyte antigen matching between donor and recipient is not required (7). In animal models, transplantation is possible without immunosuppressive agents and tolerance induction is described in both patients and animals (6, 8). This tolerance induction is alloantigen-specific for other organs of the same donor and can even override priming (9, 10). Many authors argue that this is dependent on a minimum amount of rejection and intrahepatic lymphocyte turnover (6, 11). Possible explanations for the tolerance induction include apoptosis of the reactive lymphocytes (12) or migration of donor passenger leukocytes into recipient lymphoid tissue (8). On the other hand, the fact that the fetal liver is a site of hematopoiesis, together with the immature phenotypic characteristics of many intrahepatic lymphocytes, has led to the hypothesis that the liver is an extralymphatic site of T cell development (11).

The apparent difference of liver allografts to other solid organs despite similarities in the immune response led us to focus our study on the graft itself. Using the actual clinical situation with liver biopsies of patients after transplantation as a model, we intended to examine the proliferation rate and corresponding phenotype of mononuclear leukocytes during allograft rejection and the relevance for transplantation outcome. The percentage of proliferating cells was assessed by their expression of the nuclear antigen Ki-67, which is specific for the late G1, S, G2, and M phases of the cell cycle (13). Ki-67+ cells were then further characterized for their expression of the subset specific antigens (14) CD4 and CD8 (T lymphocytes), CD20 (B lymphocytes), CD57 (NK cells), and CD68 (macrophages). Naive and `memory' T lymphocytes were distinguished by the two isoforms CD45RA and CD45RO of the leukocyte common antigen family (LCA, CD45).


   EXPERIMENTAL PROCEDURES
TOP
 ABSTRACT
 INTRODUCTION
 EXPERIMENTAL PROCEDURES
RESULTS
 DISCUSSION
 REFERENCES
 
Subjects
Acute rejection
Liver specimens, obtained by percutaneous needle biopsy from 10 patients (4 male/6 female; age range 25–60 years) with acute cellular rejection after orthotopic liver transplantation, were studied (median time posttransplant 8 days; range 6–26 days). All biopsies were placed into 10% buffered formalin (pH 7.4), embedded in low-temperature paraffin wax, and stored until use. Indications for transplantation were primary biliary cirrhosis (four patients), primary sclerosing cholangitis (four patients), and chronic active hepatitis, alcoholic liver disease, fulminant hepatic failure due to acetaminophen overdose, and graft failure due to chronic rejection (one patient each). After the transplantation, patients received standard immunosuppressive therapy with prednisolone, azathioprine, and cyclosporin A. Acute rejection was diagnosed using clinical and biochemical criteria in combination with histological evaluation of the biopsies according to standard scoring systems (6). The main histological features of rejection assessed were portal inflammation, bile duct damage, and subendothelial inflammation, each scored on a scale of 0 (none) to 3 (severe). The combined rejection scores of the biopsies used in this study were 6/9 or above. All patients with acute rejection were treated with a daily regimen of 1 g of methylprednisolone intravenously (i.v.) for 3 days. After treatment, a second liver biopsy was taken to confirm the resolution of the rejection episode. In all cases, a significant reduction of the total rejection scores was achieved, with maximum scores of 4/9.

Chronic rejection
Liver biopsies from 10 patients (1 male/9 female; age range 20–58 years) with chronic ductopenic rejection after transplantation were studied (median time posttransplant 6.5 months; range 3.5–9.5 months). The specimens were obtained and processed as described above. Indications for transplantation were primary biliary cirrhosis, fulminant hepatic failure due to acetaminophen overdose, and chronic rejection of the first allograft in three patients each and chronic hepatitis B in one patient. The immunosuppressive treatment of patients before the biopsy included either prednisolone, azathioprine, and cyclosporin A (six patients) or prednisolone and tacrolimus (four patients). The diagnosis of chronic rejection was based on a combination of standard clinico-biochemical features and histological criteria (6), including bile duct loss and obliterative arteriopathy. During follow-up, 8 of the 10 patients consequently lost their graft due to chronic rejection, whereas the other two patients recovered after their immunosuppressive regimen was changed from cyclosporin A to tacrolimus.

No rejection
Specimens of liver tissue were obtained from 10 patients (2 male/8 female; age range 20–64 years) and processed as described above, with routine biopsies on day 7 posttransplant, as per management protocol for postoperative care in the Scottish Liver Transplant Unit. Indications for transplantation were primary biliary cirrhosis (four patients), fulminant hepatic failure due to acetaminophen overdose (three patients), and alcoholic liver disease, cryptogenic cirrhosis, and hepatocellular carcinoma (one patient each). The standard immunosuppressive posttransplant therapy consisted of prednisolone, azathioprine, and cyclosporin A in all cases. None of the patients showed clinico-biochemical signs of acute or chronic rejection; histological evaluation of the liver biopsies amounted only to mild inflammation, with a score of 3/9 or less in each case. During follow-up, none of the patients developed an episode of acute or chronic rejection and no further biopsies were taken.

Controls
Control liver tissue was obtained from biopsies of 15 patients (8 male/7 female; age range 25–67) undergoing routine staging for malignant lymphoma and staging of colon carcinoma at the time of the resection or were taken before therapy with methotrexate for psoriasis. All liver specimens were histologically evaluated and reported as normal. Prior to biopsy, no clinical signs of liver disease were present, and liver function tests were normal in all 15 patients. The biopsies were processed as described above.

Immunocytochemistry
Serial sections (3 µm in thickness) of the paraffin-embedded biopsies were mounted on glass slides, air-dried at room temperature, dewaxed in xylene, and rehydrated in a graded ethanol series. They were pretreated for antigen retrieval by microwaving in 10 mM EDTA buffer (Sigma, St. Louis, Mo.) for 3 x 5 min (mAb CD4) or in 10 mM citrate buffer for 2 x 5 min (all other antibodies), washed, and incubated for 40 min at room temperature with the monoclonal antibodies anti-Ki-67 (MIB-1, Coulter-Immunotech, U.K., Ltd.); anti-CD4 (Novocastra Lab., U.K., Ltd.); anti-CD8, anti-CD20, anti-CD45RA, anti-CD45RO, anti-CD68 (Dako, U.K., Ltd.); and anti-CD57 (Zymed Lab. Inc., U.K., Ltd.). Positive staining was visualized by the standard avidin-biotin-peroxidase complex method, with diaminobenzidine as chromogen. For double immunostaining, the sections were then incubated with the second primary antibody, followed by streptavidin-biotin-alkaline phosphatase with Vector Red (Vector Lab., U.K.) as chromogen. All slides were counterstained with hematoxylin. Negative controls for each run were performed without primary antibody. The number of cells staining positively was counted `blindly' by two independent observers (M.M.D. and D.J.H.) by using the Zeiss HOME microscope at x40 magnification. At least five portal tracts were studied per section with the exception of specimens with chronic rejection, in which all visible portal tracts were examined. The degree of concordance between the two observers was >95%.

Statistical analysis
Student's t test was used to compare the mean percentage (± SEM) of cells staining positively in the biopsies of each subgroup of patients. Results with a P value of less than 0.05 were considered significant.


   RESULTS
TOP
 ABSTRACT
 INTRODUCTION
 EXPERIMENTAL PROCEDURES
 RESULTS
DISCUSSION
 REFERENCES
 
Intrahepatic proliferation of mononuclear leukocytes after liver transplantation
Proliferation of intrahepatic leukocytes was assessed by their expression of the nuclear antigen Ki-67, which is closely associated with the cell cycle (13). Biopsies from patients without liver disease were used to study the proliferation rate in normal liver tissue. In these, Ki-67+ mononuclear leukocytes were rarely observed, with a mean percentage of 1 ± 0.3% ( Fig. 1), and were located throughout the liver parenchyma and inside the portal tracts ( Fig. 2).



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  		Figure 1. Ki-67 expression of mononuclear leukocytes in normal liver tissue and after transplantation. The number of Ki-67+ cells is expressed as mean percentage ± SEM of all mononuclear leukocytes (normal tissue: n=15; all other tissue: n=10).








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  		Figure 2. Ki-67 expression of mononuclear leukocytes in normal liver tissue and after transplantation. A) Occasional expression in mononuclear leukocytes in normal tissue; B) increased expression in periportal mononuclear leukocytes posttransplant without rejection; C) highly increased expression in periportal mononuclear leukocytes during acute rejection; D) reduced expression after steroid treatment for acute rejection; E) increased expression in periportal and intraparenchymal mononuclear leukocytes during chronic rejection; F) negative control (no primary antibody) during acute rejection.

Biopsies taken on day 7 posttransplant from patients without clinical rejection revealed increased numbers of mononuclear leukocytes expressing Ki-67 compared with normal liver tissue (15.4±2.4% vs. 1±0.3%, P=0.0038). These were located predominantly inside the portal tracts.

During acute rejection, the percentage of proliferating mononuclear leukocytes rose to 61.1 ± 1.9%, significantly higher than in patients without rejection (P<0.0001). The distribution of Ki-67+ cells was mainly inside the portal tracts, with some present in the adjacent liver parenchyma. After treatment with corticosteroids, the number of mononuclear leukocytes expressing Ki-67 fell to 23.2 ± 2.5%. This was significant compared with the previous biopsies during acute rejection (P<0.0001), but not when compared with biopsies from patients without rejection (P=0.052).

During chronic rejection, the number of mononuclear leukocytes in cell cycle was 24.9 ± 5.9%, significantly different from biopsies from patients without liver disease (P=0.004) or with acute rejection (P=0.0004), but not significantly different from the biopsies of patients without rejection (P=0.17). More of the Ki-67+ cells were present within the liver parenchyma, but, again, the majority were situated inside the portal areas.

Proliferating leukocytes are predominantly CD4+ T lymphocytes
To study the phenotype of mononuclear leukocytes proliferating after transplantation, we used a double staining method to assess which subsets of cells were also expressing the nuclear antigen Ki-67. T lymphocytes were identified by CD4 and CD8, B lymphocytes by CD20, NK cells by CD57, and macrophages by CD68 (14).

CD4+ T lymphocytes were located predominantly inside the portal tracts in all biopsies posttransplant. In biopsies of patients without rejection, CD4+ lymphocytes represented 31.6 ± 3.3% of all lymphocytes ( Fig. 3). During acute rejection, the number of CD4+ cells was significantly higher with 62.6 ± 3.6% (P=0.0031). Treatment of acute rejection with i.v. corticosteroids resulted in a significant reduction of CD4+ cells to 38.3 ± 4.4% (P=0.013), similar to chronic rejection with a percentage of 32.8 ± 8.6% (62.6±3.6% vs. 32.8±8.6%, P=0.033).



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  		Figure 3. Expression of CD4 and CD8 in lymphocytes in liver tissue after transplantation. The number of CD4+ and CD8+ lymphocytes is expressed as mean percentage ± SEM of all lymphocytes (n=10).

Like CD4+ T lymphocytes, proliferating cells were located predominantly inside the portal tracts in biopsies of patients without rejection. Accordingly, the majority of Ki-67+ cells were CD4+ on double staining, with a mean percentage of 90.0 ± 3.0% ( Fig. 4). A similar distribution of CD4+ T lymphocytes was observed during acute rejection, with 96.0 ± 1.3% of proliferating cells positive for CD4 ( Fig. 5). Treatment of acute rejection with corticosteroids did not change the distribution of cells, but significantly reduced the percentage of CD4+ T lymphocytes in cell cycle to 87.8 ± 1.6% (P=0.029). During chronic rejection, most of the CD4+ T lymphocytes remained located inside the portal tracts, but the percentage of CD4+ proliferating cells (75.5±2.5%) was significantly lower compared with acute rejection (P=0.0054) or no rejection (P=0.034).



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  		Figure 4. Expression of CD4 and CD8 in proliferating lymphocytes in liver tissue after transplantation. The number of CD4+ and CD8+ T lymphocytes is expressed as mean percentage ± SEM of all Ki-67+ cells (n=10).




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  		Figure 5. Double staining of CD4+, Ki-67+ and CD8+, Ki-67+ T lymphocytes in liver tissue after transplantation (brown staining: CD4, CD8; red staining: Ki-67; blue staining: hematoxylin). A) Predominance of proliferating CD4+ T lymphocytes in portal tracts posttransplant; B) minority of proliferating CD8+ T lymphocytes in portal tracts posttransplant.

In contrast to CD4+ T lymphocytes, CD8+ T cells were situated predominantly within the liver parenchyma, with only a minority inside the portal tracts in all tissues posttransplant. In biopsies of patients without rejection, CD8+ lymphocytes represented 50.5 ± 10.4% of all lymphocytes, with no significant changes to the percentage during acute or chronic rejection ( Fig. 3). In addition to CD4+ T lymphocytes, only CD8+ T lymphocytes were occasionally positive for the nuclear antigen Ki-67 on double staining ( Fig. 4and Fig. 5). No significant changes were detected in the percentage of CD8+ proliferating lymphocytes between the four groups of biopsies.

CD20+ B lymphocytes were occasionally present within some but not all of the portal tracts, accounting for less than 5% of all lymphocytes. Positive double staining of CD20, CD57, or CD68 on Ki-67+ cells was not observed.

Proliferating T lymphocytes are both naive and memory cells
To establish whether the proliferating CD4+ T lymphocytes were of the naive or memory phenotype, we used the double staining method to examine proliferating lymphocytes for their expression of the two isoforms, CD45RA (naive lymphocytes) and CD45RO (memory lymphocytes), of the leukocyte common antigen family (LCA, CD45). The number of naive and memory T cells was expressed as the percentage of all lymphocytes that were either CD45RA+ or CD45RO+.

In all biopsies, CD45RA+ lymphocytes were predominantly located inside the portal tracts. During acute rejection, naive lymphocytes ( Fig. 6) increased significantly compared with patients without rejection (38.9±2.3% vs. 25.3±1.7%, P=0.018). However, treatment with corticosteroids significantly reduced this number (38.9±2.3% vs. 29.8±0.3, P=0.034). There was no significant difference in the percentage of naive lymphocytes during acute compared with chronic rejection.



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  		Figure 6. Expression of CD45RA and CD45RO in lymphocytes in liver tissue after transplantation. The number of CD45RA+ and CD45RO+ lymphocytes is expressed as mean percentage ± SEM of all lymphocytes (n=10).

Of the proliferating lymphocytes ( Fig. 7 and Fig. 8), CD45RA+ cells represented 40.9 ± 3.3% and 47.3 ± 3.3% in tissues of patients without rejection or with acute rejection, respectively. Steroid treatment of acute rejection did not change this percentage, but during chronic rejection (16.7±3.2%) it was significantly lower compared with acute (P=0.0069) and no rejection (P=0.013).



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  		Figure 7. Expression of CD45RA and CD45RO in proliferating lymphocytes in liver tissue after transplantation. The number of CD45RA+ and CD45RO+ lymphocytes is expressed as mean percentage ± SEM of all Ki-67+ lymphocytes (n=10).




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  		Figure 8. Double staining of CD45RA+, Ki-67+ and CD45RO+, Ki-67+ lymphocytes in liver tissue after transplantation (brown staining: CD45RA, CD45RO; red staining: Ki-67; blue staining: hematoxylin): proliferation of A) naive (CD45RA+) and B) memory (CD45RO+) lymphocytes posttransplant.

In all biopsies posttransplant, CD45RO+ lymphocytes were present in the parenchyma throughout the liver lobules, but the majority were situated inside the portal areas. No significant difference was observed in the percentage of CD45RO+ cells ( Fig. 6) from biopsies of patients without rejection and those with acute rejection, but the percentage increased significantly after i.v. treatment with corticosteroids (52.3±1.4% vs. 40.7±0.9%, P=0.0064). The percentage was significantly higher during chronic rejection compared with acute rejection (55.7±2.7% vs. 40.7±0.9%, P=0.034).

CD45RO+ lymphocytes represented 53.8 ± 0.2% of Ki-67+ proliferating cells ( Fig. 7and Fig. 8) in tissue from patients without rejection. There was no significant change during acute rejection; during chronic rejection, the percentage of memory lymphocytes were 80.3 ± 4.4%, which was significantly higher than in biopsies from patients with acute rejection (55.7±1.5%, P=0.033) and without rejection (53.8±0.2%, P=0.026).


   DISCUSSION
TOP
 ABSTRACT
 INTRODUCTION
 EXPERIMENTAL PROCEDURES
 RESULTS
 DISCUSSION
REFERENCES
 
Our results indicate two findings that might be important for the current view of the mechanism of allograft rejection. First, we were able to show that proliferation (assessed by Ki-67) of mononuclear leukocytes inside the human liver allograft was a prominent feature of rejection, suggesting that a significant proportion of the `inflammatory infiltrate' is due to local expansion rather than migration. Second, leukocytes in cell cycle (as assessed by double staining) were predominantly CD4+, CD45RA+, and CD4+, CD45RO+ T lymphocytes—both naive and memory T lymphocytes. This would implicate that the primary immune response with proliferation and differentiation of naive T lymphocytes might not be restricted to lymphatic tissue, but could also occur within the allograft, at least during liver graft rejection.

The current concept of homing and migration patterns of lymphocyte subsets (4, 15) suggests that naive T lymphocytes recirculate preferentially through lymphoid tissue, which provides the necessary microenvironment for antigen stimulation. Naive lymphocytes are able to enter lymph nodes through high endothelial venules, distinct from other microvessel endothelia (16). In contrast, T lymphocytes in nonlymphatic tissue, e.g., during inflammation, are predominantly of the memory and `effector' phenotype, due to their ability of transendothelial migration (5, 17). Their rapid increase in number during inflammation has been accounted for by migration rather than local expansion.

Our findings indicate exactly the opposite occurrence during hepatic allograft rejection, with a substantial number of naive lymphocytes residing in the graft after transplantation and proliferation of both naive and memory T lymphocytes within the graft during the immune response. This could suggest a general difference in allograft rejection from other forms of inflammation, because naive T lymphocytes are able to migrate into the graft and there are sufficient signals to activate them. Indeed, results of our own group show proliferation of less than 10% of mononuclear leukocytes in liver biopsies of patients with primary biliary cirrhosis (unpublished data). Moreover, early reports in kidney transplantation have already demonstrated proliferation of lymphocytes and, occasionally, other lymphoid cells such as monocytes within the allograft (18–20), linking specifically the lymphocyte proliferation to rejection. In other models of heart and liver rejection, aggregates of dendritic cells and lymphoblasts were shown within the graft (21, 22), indicating in situ stimulation of the lymphocytes. In contrast, only newer studies in kidney and heart allograft rejection were able to describe the ratio between naive and memory T cells. In both organs, memory T lymphocytes increased during rejection and data on proliferation were not provided (23, 24).

On the other hand, recent publications have described intrahepatic subpopulations of naive T lymphocytes capable of proliferation and T cell receptor rearrangement (25–27) leading to the hypothesis of extralymphatic T cell development in the liver. Naive T cells seem to be able to migrate into the liver, probably through sinusoidal fenestrations comparable to splenic sinusoidal pores (28). Additional support for intrahepatic T cell development comes from reports linking the liver to oral tolerance, e.g., tolerance induction by injecting antigen-presenting cells into the portal vein in contrast to systemic veins or abrogation of oral tolerance induction by short circuiting the liver (11). These observations attribute properties to the liver usually associated with lymphatic tissue. Intrahepatic T cell depletion might be mediated by apoptosis induced by Fas (CD95, APO-1) (11, 29) or galactin-1, which preferentially causes cell death in CD45RO+ T lymphocytes (30). In contrast, proliferation, which is closely linked to apoptosis in early stages with occasional expression of similar signals including Ki-67 (31), could be stimulated by intrahepatic dendritic cells (32) or endothelial cells (33). The final decision to undergo apoptosis or proliferation would be influenced by additional signals such as the anti-apoptotic protein bcl-2 (34). We recently found high levels of bcl-2 in intrahepatic lymphocytes of patients with liver allograft rejection (35), whereas lymphocytes in liver biopsies of patients without rejection expressed high levels of Fas (36). Intrahepatic T cell development might explain the unique immunological properties of the liver as an allograft, such as inducing tolerance for other subsequently and previously transplanted solid organs comparable to the thymus (37), as well as transferring specific immune memories such as allergies and autoimmune disorders of the donor to the recipient comparable to bone marrow transplantation (38).

We present data that challenge the view that solid organs, and specifically the liver, only represent a target for the immune system after transplantation. Recent publications on transplantation in patients and animal models (including after thymectomy) have led to the hypothesis that the migration of donor passenger leukocytes into recipient lymphoid tissue influences transplantation outcome (8). Our results suggest that the graft itself might be relevant for the development of the immune response. Either all solid organs are partly involved in the immune reaction, providing a location for allorecognition and the subsequent primary lymphocyte activation, or the liver specifically has immunological properties comparable to lymphatic tissue. These hypotheses would add to the current perspective not only on transplantation, but of basic immunology with respect to T lymphocyte-mediated immune responses and tolerance induction.


   ACKNOWLEDGMENTS
 
Supported by the Medical Research Council, Great Britain.


   FOOTNOTES
 
1 Correspondence: Department of Pathology, University Medical School, University of Edinburgh, Teviot Place. Edinburgh EH8 9AG, Scotland, U.K. E-mail: M.Dollinger{at}ed.ac.uk

2 Abbreviations: i.v., intravenous; NK cells, natural killer cells.

Received for publication December 10, 1997. Accepted for publication .


   REFERENCES
TOP
 ABSTRACT
 INTRODUCTION
 EXPERIMENTAL PROCEDURES
 RESULTS
 DISCUSSION
 REFERENCES
 

  1. Fisher, L., Henley, K., and Lucey, M. (1995) Acute cellular rejection after liver transplantation: variability, morbidity and mortality. Liver Transplant Surg. 1, 10–15
  2. Neuberger, J. (1995) Liver allograft rejection—current concepts on diagnosis and treatment. J. Hepatol. 23 (Suppl.1), 54–61
  3. Fabre, J. W. (1996) The role of polymorphic donor peptides in allograft recognition and rejection. Immunol. Rev. 154, 21–43[Medline]
  4. Pape, K. A., Kearney, E. R., Khoruts, A., Mondino, A., Merica, R., Chen, Z.-M., Ingulli, E., White, J., Johnson, J. G., and Jenkins, M. K. (1997) Use of adoptive transfer of T-cell-antigen-receptor-transgenic T cells for the study of T cell activation in vivo. Immunol. Rev. 156, 67–78[Medline]
  5. Brezinschek, R. I., Lipsky, P. E., Galea, P., Vita, R., and Oppenheimer-Marks, N. (1995) Phenotypic characterization of CD4+ T cells that exhibit a transendothelilal migratory capacity. J. Immunol. 154, 3062–3077[Abstract]
  6. International Working Party. (1995) Terminology for hepatic allograft rejection. Hepatology 22, 648–654[Medline]
  7. Balan, V., Rakela, J., Vinayek, R., Irish, W., McMichael, J., Reyes, J., Fung, J. J., and Starzl, T. E. (1997) Does HLA mismatching influence hepatic allograft survival? Hepatology 26 (Suppl. 4), A124 (abstr.)
  8. Starzl, T. E., Demetris, A. J., Murase, N., Trucco, M., Thomson, A. W., and Rao, A. S. (1996) The lost chord: microchimerism and allograft survival. Immunol. Today 17, 577–588[Medline]
  9. Calne, R. Y., Sells, R. A., Pena, J. R., Davis, D. R., Millard, P. R., Herbertson, B. M., Binns, R. M., and Davies, D.A.L. (1969) Induction of immunological tolerance by porcine liver allografts. Nature (London) 233, 472–476
  10. Kamada, N., Davies, H. F. S., and Roser, B. (1981) Reversal of transplantation immunity by liver grafting. Nature (London) 292, 840–842[Medline]
  11. Crispe, I. N., and Mehal, W. Z. (1996) Strange brew: T cells in the liver. Immunol. Today 17, 522–525[Medline]
  12. Quian, S., Lu, L., Fu, F., Li, Y., Li, W., Starzl, T. E., Fung, J. J., and Thomson, A. W. (1997) Apoptosis within spontaneously accepted mouse liver allografts. J. Immunol. 158, 4654–4661[Abstract]
  13. Gerdes, J., Lemke, H., Baisch, H., Wacker, H., Schwab, U., and Stein, H. (1984) Cell cycle analysis of the cell-associated human nuclear antigen defined by the monoclonal antibody Ki-67. J. Immunol. 133, 1710–1715[Abstract]
  14. Abbas, A. K., Lichtman, A. H., and Pober, J. S. (1994) Cellular and Molecular Immunology, pp. 431–435, W. B. Saunders Company, Philadelphia
  15. Mackay, C. R. (1993) Homing of naive, memory and effector lymphocytes. Curr. Opin. Immunol. 5, 423–427[Medline]
  16. Szekanecz, Z., Humphries, M. J., and Ager, A. (1992) Lymphocyte adhesion to high endothelium is mediated by two ß1 integrin receptors for fibronectin, {alpha}4ß1 and {alpha}5ß1. J. Cell. Sci. 101, 885–894[Abstract/Free Full Text]
  17. Oppenheimer-Marks, N., and Lipsky, P. E. (1997) Migration of naive and memory T cells. Immunol Today 18, 456–457[Medline]
  18. Nemlander, A., Soots, A., von Willebrand, E., Husberg, B., and Häyry, P. (1982) Redistribution of renal allograft-responding leukocytes during rejection. J. Exp. Med. 156, 1087–1100[Abstract/Free Full Text]
  19. Häyry, P., and von Willebrand, E. (1983) Transplant aspiration cytology in the evaluation of a renal allograft. In Transplantation and Clinical Immunology (Jouraine, J. L., ed) Vol. 15, pp. 124–137, Elsevier Science B. V., Amsterdam
  20. von Willebrand, E., Taskinen, E., Ahonen, J., and Häyry, P. (1983) Recent modifications in the fine needle aspiration biopsy of human renal allografts. Transpl. Proc. 15, 1195–1197
  21. Forbes, R. D. C., Parfrey, N. A., Gomersall, M., Darden, A. G., and Guttmann, R. D. (1986) Dendritic cell-lymphoid cell aggregation and major histocompatibility antigen expression during rat cardiac allograft rejection. J. Exp. Med. 164, 1239–1258[Abstract/Free Full Text]
  22. Demetris, A. J., Qian, S., Sun, H., Fung, J. J., Yagihashi, A., Murase, N., Iwaki, Y., Gambrell, E., and Starzl, T. E. (1991) Early events in liver allograft rejection. Am. J. Pathol. 138, 609–618[Abstract]
  23. Ibrahim, S., Dawson, D. V., and SanFilippo, F. (1995) Predominant infiltration of rejecting human renal allografts with T cells expressing CD8 and CD45RO. Transplantation 59, 724–728[Medline]
  24. Ibrahim, S., Dawson, D. V., Van Trigt, P., and SanFilippo, F. (1993) Differential infiltration by CD45RO and CD45RA subsets of T cells associated with human heart allograft rejection. Am. J. Pathol. 142, 1794–1803[Abstract]
  25. Collins, C., Norris, S., McEntee, G., Traynor, O., Bruno, L., von Boehmer, H., Hegarty, J., and O'Farrelly C. (1996) RAG1, RAG2 and pre-T cell receptor {alpha} chain expression by adult human hepatic T cells: evidence for extrathymic T cell maturation. Eur. J. Immunol. 26, 3114–3118
  26. Sato, K., Ohtsuka, K., Hasegawa, K., Yamagiwa, S., Watanabe, H., Asakura, H., and Abo, T. (1995) Evidence for extrathymic generation of intermediate T cell receptor cells in the liver revealed in thymectomized, irradiated mice subjected to bone marrow transplantation. J. Exp. Med. 182, 759–767[Abstract/Free Full Text]
  27. Makino, Y., Yamagata, N., Sasho, T., Adachi, Y., Kanno, R., Koseki, H., Kanno, M., and Taniguchi, M. (1993) Extrathymic development of V{alpha}14-positive T cells. J. Exp. Med. 177, 1399–1408[Abstract/Free Full Text]
  28. Bianchi, E., Bender, J. R., Blasi, F., and Pardi R. (1997) Through and beyond the wall: late steps in leukocyte transendothelial migration. Immunol. Today 18, 586–591[Medline]
  29. Galle, P. R., Hofmann, W. J., Walczak, H., Schaller, H., Otto, G., Sremmel, W., Krammer, P. H., and Runkel, L. (1995) Involvement of CD95 (APO-1/Fas) receptor and ligand in liver damage. J. Exp. Med. 182, 1223–1230[Abstract/Free Full Text]
  30. Perillo, N. L., Pace, K. E., Seilhamer, J. J., and Baum, L. G. (1995) Apoptosis of T cells mediated by galectin-1. Nature (London) 378, 736–739[Medline]
  31. Coates, P. J., Hales, S. A., and Hall, P. A. (1996) The association between cell proliferation and apoptosis: studies using the cell-cycle associated proteins Ki-67 and DNA polymerase alpha. J. Pathol. 178, 71–77[Medline]
  32. Woo, J. Lu, L., Rao, A. S., Li, Y., Subbotin, V., Starzl, T. E., and Thomson, A. W. (1994) Isolation, phenotype, and allostimulatory activity of mouse liver dendritic cells. Transplantation 58, 484–491[Medline]
  33. Knolle, P. A., Scmitt, E., Duchmann, R., Meyer zum Bueschenfelde, K-H., Gerken, G., and Lohse, A. W. (1997) Liver sinusoidal endothelial cells prime naive T cells and induce a Th2-shift: implication for induction of tolerance in the liver. Hepatology 26 (Suppl. 4), A1267 (abstr.)
  34. Itoh, N., Tsujimoto, Y., and Nagata, S. (1993) Effect of bcl-2 on Fas antigen-mediated cell death. J. Immunol; 151, 621–627[Abstract]
  35. Dollinger, M. M., Graham, A., Plevris, J. N., Hayes, P.C., Howie, S. E. M., and Harrison, D. H. (1997) Fas and bcl-2 expression during acute and chronic rejection following orthotopic liver transplantation. J. Hepatol. 26 (Suppl. 1), 149 (abstr.)
  36. Dollinger, M. M., Howie, S. E. M., Graham, A., Plevris, J. N., Hayes, P. C., and Harrison, D. H. (1998) Pathways of T cell-mediated cytotoxicity in hepatic allograft rejection. J. Hepatol. 28 (Suppl. 1), 61 (abstr).
  37. Sayegh, M. H., Perico, N., Gallon, L., Imberti, O., Hancock, W. W., Remuzzi, G., and Carpenter, C. B. (1994) Mechanisms of acquired thymic unresponsiveness to renal allografts. Transplantation 58, 125–132[Medline]
  38. Legendre, C., Caillat-Zucman, S., Samuel, D., Morelon, S., Bismuth, H., Bach, J.-F., and Kreis, H. (1997) Transfer of symptomatic peanut allergy to the recipient of a combined liver-and-kidney transplant. New Engl. J. Med. 337, 822–824[Free Full Text]



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M. Heydtmann, D. Hardie, P. L. Shields, J. Faint, C. D. Buckley, J. J. Campbell, M. Salmon, and D. H. Adams
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