Intercellular adhesion molecules and vascular cell adhesion molecule-1 and the kidney.

Adhesion molecules such as intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 are expressed in the kidney and are regulated by proinflammatory cytokines. These adhesion molecules play an important role in the binding and activation process of leukocytes and are of importance in inflammatory kidney diseases. This review article describes current knowledge regarding the structure, expression, and functional role of adhesion molecules and their significance in immune-mediated renal diseases.     

Intercellular adhesion molecule-1 expression in human kidneys with glomerulonephritis.

Intercellular adhesion molecule-1 (ICAM-1) plays an important role in immune responses. Expression of this molecule was examined on cryostat sections of 15 normal human and 112 glomerulonephritic kidneys using a specific monoclonal antibody and the indirect immunoperoxidase staining technique. The expression of ICAM-1 on renal structures was compared to that of HLA-DQ, -DR, -DR/DP and -DP antigens. On normal kidneys ICAM-1 was observed on some Bowman's capsular cells and on single glomerular cells which probably represent endothelial and mesangial cells. ICAM-1 was present on peritubular capillaries and on vascular endothelium of large vessels as well as on fibroblasts, whereas no expression of ICAM-1 on proximal tubular epithelial cells (PTECs) was detected. In normal renal tissues the distribution of ICAM-1 was similar to that of HLA-DQ and -DP antigens. In kidneys with different forms of glomerulonephritis especially in association with interstitial inflammation, an abnormal expression of ICAM-1 on PTECs was frequently correlated with aberrant expression of HLA-DQ and -DP antigens. These results further support the hypothesis that PTECs may participate in cell-mediated immune reactions in glomerulonephritis.     

Rat cytomegalovirus infection in kidney allograft recipients is associated with increased expression of intracellular adhesion molecule-1 vascular adhesion molecule-1, and their ligands leukocyte function antigen-1 and very late antigen-4 in the graft

BACKGROUND: Cytomegalovirus (CMV) infection is suggested to be a risk factor for chronic rejection. We have recently shown that rat CMV (RCMV) increases the inflammatory response and accelerates chronic rejection in a model of rat kidney allograft. In this study, the early inflammatory response and time-related expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) and their ligands, leukocyte function antigen-1 (LFA-1) and very late antigen-4 (VLA-4), in the grafts were investigated in RCMV-infected rats and compared to noninfected rats developing chronic rejection. METHODS: Transplantations were performed in a rat strain combination of DA (RT1a)->BN (RT1n) receiving triple drug immunosuppression. One group of rats was infected with RCMV, and the other was left uninfected. The grafts were harvested at different time points after transplantation. The adhesion molecules, their ligands and activation markers, MHC class II antigens and interleukin-2-receptors (IL-2-R), were demonstrated by monoclonal antibodies and immunoperoxidase staining from frozen sections of the grafts. Graft histology was evaluated according to the Banff criteria. RESULTS: RCMV caused a significant, prolonged increase of VCAM-1 and ICAM-1 expression in the vascular endothelium compared to the noninfected grafts. Also, the number of cells expressing activation markers, LFA-1 and VLA-4 was significantly enhanced in these animals. Significantly enhanced histological changes of chronic rejection were seen in the RCMV-infected group. CONCLUSIONS: Prolonged, increased expression of ICAM-1 and VCAM-1, and increased numbers of inflammatory cells expressing their ligands in the CMV infected grafts, were associated with accelerated chronic allograft nephropathy.     

Specific acceptance of fetal bowel allograft in mice after combined treatment with anti-intercellular adhesion molecule-1 and leukocyte function-associated antigen-1 antibodies.

OBJECTIVE: The aim of this study was to see whether tolerance could be induced by simultaneous administration of monoclonal antibodies (MoAbs) to intercellular adhesion molecule-1 (ICAM-1) and leukocyte function-associated antigen-1 (LFA-1) after transplantation of fetal small bowel between fully incompatible mice strains. METHODS: Fetal small bowel from either BALB/c (H-2d) or C3H/He (H-2k) mice was transplanted into the space between the peritoneum and rectus abdominis of adult C3H/He recipient mice. Syngeneic (n = 6) and two allogeneic transplant groups were made. In one of the allogeneic groups (n = 8), no immunosuppressant was given. In the other allogeneic group (n = 13), both anti-LFA-1 and anti-ICAM-1 MoAbs (50 micrograms each/mouse/day) were given intraperitoneally after transplantation for the first 4 weeks. In the syngeneic and untreated allogeneic groups, all mice were killed 4 weeks after transplantation. In the treated allogeneic group, eight mice were killed 6 weeks after cessation of the MoAb treatment. At the time the mice were killed, the bowel graft as well as the recipient spleen were taken for histologic analysis and cytotoxic T-lymphocyte (CTL) assay, respectively. Each mouse in the remaining treated five mice was transplanted with BALB/c and C57BL/6 (as third-party) full-thickness skin simultaneously 8 weeks after cessation of the MoAb treatment. RESULTS: All grafts in the syngeneic group survived with normally developing villi, whereas all grafts in the untreated allogeneic group disappeared. In the treated allogeneic group, all allografts developed normal mucosa without any sign of rejection. Splenocytes from the recipient mice in the untreated allogeneic group showed increased CTL induction against donor-type alloantigen (p < 0.005), compared with that in the syngeneic group. Suppressed CTL induction against donor-type alloantigen was observed in the treated allografted recipient (p < 0.001), whereas CTL induction against third-party alloantigen was intact (p = NS). Third-party skin graft was normally rejected within 10 days, whereas donor-type skin graft was accepted in all mice tested. CONCLUSIONS: Specific tolerance for fetal bowel allografts could be induced by a relatively short-term treatment with anti-ICAM-1 and anti-LFA-1 MoAbs. This mode of immunointervention could perhaps be applied to humans undergoing small-bowel transplantation.     

Expression of vascular cell adhesion molecule-1 in human renal allografts.

The expression of vascular cell adhesion molecule-1 (VCAM-1) in 11 human renal allograft biopsies and 3 normal kidney specimens was investigated by immunocytochemistry. VCAM-1 expression was correlated with the degree of CD3+ T cell infiltration and the clinicopathologic diagnosis of acute rejection. CD3+ infiltrates were seen in all biopsies with rejection, but not in normal biopsies or one with acute tubular necrosis, and were accompanied by CD68+ monocyte/macrophage infiltrates. In normal biopsies, VCAM-1 was present on occasional tubules, where its expression was patchy and restricted to the basolateral surface of cells with slight cytoplasmic staining. The total number of tubules expressing VCAM-1 significantly increased in specimens infiltrated with CD3+ T cells. Moreover, in these infiltrated biopsy specimens, VCAM-1 was present throughout the cytoplasm of tubular cells concentrated on the basolateral surface. VCAM-1 was also observed on vascular endothelial cells where its expression correlated with the degree of CD3+ infiltrate. Mean scores (0 to 3+) for endothelial VCAM-1 expression increased from 0 (CD3+ score, 0) to a mean score of 2.25 in association with CD3+ T cell infiltrates (CD3+ score, 3). Endothelial VCAM-1 was predominantly on vessels in areas of infiltrate, including peritubular capillaries, venules, and arterioles, but was notably absent on glomerular endothelium. VCAM-1 also stained mesangial cells in an occasional CD3+ infiltrated specimen. It was concluded that the expression of VCAM-1 is increased on renal tubules and renovascular endothelium in rejecting renal allografts in association with CD3+ infiltrates.(ABSTRACT TRUNCATED AT 250 WORDS)     

Analysis of cloned T cell function. II. Differential blockade of various cloned T cell functions by cyclosporine

Cyclosporine has profound suppressive effects on selected in vitro functions of cloned T lymphocytes. Cyclosporine inhibits the antigen-induced proliferation of the helper T cell clone 12-11. The effective dose required to reduce this response by 50% (ED50) is 28 ng/ml. In contrast, the proliferation of clone 12-11 induced by exogenous growth factors in secondary mixed lymphocyte culture supernatant (2 degrees MLC SN), is relatively insensitive to cyclosporine (ED50 = 4600 ng/ml). Furthermore, cyclosporine abrogates both antigen-induced and mitogen-induced secretion of lymphokines by clone 12-11, indicating that cloned helper T cell function is sensitive to cyclosporine even when interactions between specific alloantigens and their cell surface receptors are bypassed with mitogen. The suppressive effect of cyclosporine is not limited to helper T cell clones. The cytolytic T lymphocyte (CTL) clone 5MD2-2 is also sensitive to cyclosporine. Again, cyclosporine (100 ng/ml) blocks the antigen-driven, but not the exogenous lymphokine-driven, component of clone 5MD2-2 proliferation. This suppression does not result from the occlusion of antigen receptors or from antigen deformation by cyclosporine, because clone 5MD2-2 remains capable of antigen-specific cytolysis in the presence of cyclosporine concentrations that can suppress its proliferation. Finally, the ability of clone 5MD2-2 to remove IL-2 activity from culture media, a function that is significantly enhanced by contact with specific alloantigen, is not influenced by suppressive cyclosporine concentrations.     

Role of intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) in peripheral blood mononuclear cell activation by human renal carcinoma cells

We examined the role of intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) during the activation of peripheral blood mononuclear cells (PBMCs) by the human renal carcinoma cell line CaKi-1. ICAM-1 antigen expression was induced on CaKi-1 cells by incubation with either phorbol-12-myristate 13 acetate (PMA) or interferongamma (IFN-). Following a thorough washout of PMA and IFN- and subsequent paraformaldehyde fixation, CaKi-1 cell monolayers were cocultered with allogenic PBMCs. While PMA-treated CaKi-1 cells induced PBMC proliferation and interleukin-2 receptor antigen expression, this was not the case for control of IFN--treated CaKi-1 cells. Furthermore, the induced PBMC proliferation was inhibited by specific monoclonal antibodies against ICAM-1 and LFA-1. Finally, although PMA induced human leukocyte antigen (HLA)-A, B, C antigen expression on CaKi-1 cells, a monoclonal anti-body against this antigen did not inhibit PBMC proliferation. We conclude that PMA can modulate CaKi-1 cells to stimulate allogenic PBMC proliferation in an ICAM-1/LFA-1 dependent, but HLA-A, B, C-independent, fashion. This stimulation might reside in the long-term activation of protein kinase C, induced by PMA.     

Vascular cell adhesion molecule-1 is induced on endothelium during acute rejection in human cardiac allografts.

An infiltration of mononuclear leukocytes into the myocardium of a cardiac allograft is diagnostic of transplant rejection. The presence of these leukocytes implies their adhesion to, and subsequent migration through, the vascular endothelium. Intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 are endothelial proteins that have been shown to be involved in the binding of mononuclear leukocytes to the endothelium in vitro. We investigated the induction of these proteins in a random series from 99 endomyocardial biopsy specimens obtained from 1 week to 4 years after cardiac allograft transplantation. Intercellular adhesion molecule-1 was found to be expressed constitutively by the myocardial microvasculature in the recipient's original heart and in the posttransplantation biopsy specimens. No correlation was found between the presence or absence of intercellular adhesion molecule-1 expression and cellular rejection. In contrast, no endothelial expression of vascular cell adhesion molecule-1 was observed in the recipient heart or in endomyocardial biopsy specimens lacking cellular rejection. The presence of vascular cell adhesion molecule-1 significantly correlated with the presence of mild or moderate rejection. The de novo induction of vascular cell adhesion molecule-1 on the myocardial vasculature during periods of rejection, in addition to the recruitment of mononuclear leukocytes that are known to bind to this protein, suggests that the expression of this endothelial adhesion protein could be of use in diagnosing rejection.     

Monoclonal antibodies against human T cell adhesion molecules--modulation of immune function in nonhuman primates.

The cytotoxic T cell is thought to be a primary effector of allograft rejection. In vitro studies have demonstrated that the interaction between cytotoxic T cells and target cells involves cell surface adhesion molecules that result in conjugate formation, with subsequent antigen recognition, T cell activation, and target cell lysis. Experiments have also demonstrated the ability of monoclonal antibodies with specificity for two human T cell adhesion molecules, lymphocyte function associated (LFA) antigen-1 (LFA-1, CD11a, alpha-chain/CD18, beta-chain) and LFA-2 (CD2), to inhibit conjugate formation in vitro. Studies in a nonhuman primate model were undertaken to determine whether the in vivo administration of monoclonal antibodies with specificity for the alpha chain of LFA-1 (CD11a) or with specificity for CD2 could modulate in vivo T cell function. Cynomolgus monkeys (Macaca fascicularis) received 10 daily intravenous infusions of either anti-CD11a, anti-CD2 or both anti-CD11a and anti-CD2 monoclonal antibodies. Antibody administration was well tolerated and resulted in high levels of circulating murine monoclonal antibody in the peripheral circulation. Nearly all the animals generated antimurine antibodies that were specific for both idiotypic and nonidiotypic determinants of the infused mouse protein. Circulating lymphocytes and T cells were not depleted by treatment with anti-CD11a or anti-CD2 mAbs; in fact, treatment with the combination of anti-CD11a plus anti-CD2 or anti-CD11a alone led to increased numbers of circulating lymphocytes and T cells. Modulation of the LFA-1 molecule on circulating T cells occurred as a result of treatment with anti-CD11a (or the combination of anti-CD11a plus anti-CD2), whereas treatment with anti-CD2 (or anti-CD11a plus anti-CD2) did not result in modulation of the CD2 antigen despite detectable levels of circulating anti-CD2 mAb. In vivo T cell function was assessed by placement of skin allografts. As compared with treatment with saline or a control mAb, allograft survival was significantly prolonged in animals treated with anti-CD11a or combination treatment but not in animals receiving anti-CD2 alone. We conclude that the in vivo administration of anti-LFA-1 mAb may be useful for the blockade of effector T cell activity during allograft rejection, that saturation of antigen and antigen modulation may be important for efficacy of such antibody effects in vivo, and that monoclonal antibodies with specificity for functionally important T cell surface molecules may alter T cell function in vivo without lymphocyte depletion.     

Intercellular adhesion molecule 1 discriminates functionally different populations of human osteoblasts: characteristic involvement of cell cycle regulators.

The concept of differential regulation of certain adhesion molecules on different cell subsets and their relevance to cell functions has emerged in recent years. The initial event in bone remodeling is an increase in osteoclastic bone resorption and cell adhesion between osteoclastic precursors and bone marrow stromal cells or osteoblasts is known to commit the osteoclast development. Here, we show that human osteoblasts can be divided into two subsets based on the expression of the intercellular adhesion molecule (ICAM)-1; ICAM-1+ osteoblasts highly adhered to monocytes, including osteoclast precursors, produced osteoclast differentiation factor (ODF), and induced multinuclear osteoclast-like cell formation. Anti-ODF monoclonal antibody (mAb) did not inhibit the adhesion of monocytes to osteoblastic cells, whereas anti-leukocyte function-associated antigen (LFA)-1, a receptor for ICAM-1, mAb blocked the adhesion. We thereby propose that the higher affinity adhesion via LFA-1/ICAM-1 is prerequisite for efficient function of membrane-bound ODF during osteoclast maturation. The functional characteristics of ICAM-1+ osteoblasts were emphasized further by cell cycle regulation, as manifested by (i) up-regulation of p53 and p21, (ii) reduction of activity of cyclin-dependent kinase (cdk) 6, (iii) underphosphorylation of retinoblastoma protein, (iv) increased Fas but reduced bcl-2 expression, and (v) majority of cells remained at G0/G1 phase. Furthermore, ICAM-1+ osteoblasts were induced by interleukin-1beta (IL-1beta). Taken together, we propose that the differentiation of osteoblasts to ICAM-1+ subpopulation by inflammatory cytokines plays an important role in osteoporosis, which is observed in patients with chronic inflammation, because ICAM-1+ osteoblasts can bias bone turnover to bone resorption, committing osteoclast maturation through cell adhesion with its precursor, and the majority of ICAM-1+ osteoblasts arrested at G0/G1 phase. Such regulation of cell cycle arrest also is an important determinant of the life span of cells in bone in which continuous bone remodeling maintains its homeostasis.     

Peptides derived from ICAM-1 and LFA-1 modulate T cell adhesion and immune function in a mixed lymphocyte culture.

BACKGROUND: The counter receptors intercellular adhesion molecule (ICAM)-1 and lymphocyte function-associated antigen (LFA)-1 are lymphocyte cell surface adhesion proteins the interaction of which can provide signals for T cell activation. This binding event is important in T cell function, migration, and general immune system regulation. The ability to inhibit this interaction with monoclonal antibodies has proved to be therapeutically useful for several allograft rejection and autoimmune disease models. METHODS: Short peptides representing counter-receptor contact domains of LFA-1 and ICAM-1 were examined for their ability to inhibit T cell adhesion and T cell function. RESULTS: Peptides encompassing amino acids Q1-C21 and D26-K50 of ICAM-1, I237-I261 and G441-G466 of the LFA-1 alpha-subunit, and D134-Q159 of the LFA-1 beta-subunit inhibited LFA-1/ICAM-1-dependent adhesion in a phorbol-12,13-dibutyrate-induced model of tonsil T cell homotypic adhesion. This inhibition was specific to the peptide sequence and occurred without stimulation of T cell proliferation. The peptides also were effective in preventing T cell function using a one-way mixed lymphocyte reaction model for bone marrow transplantation. CONCLUSIONS: Our data suggest that these peptides or their derivatives may be useful as therapeutic modulators of LFA-1/ICAM-1 interaction during organ transplants.     

Effects of cyclosporine on the immune system of the mouse. II. Cyclosporine inhibits the effector function of primary T helper cells, but not helper cell priming

This paper describes various effects of cyclosporine on T helper (TH) cells for antibody production in the mouse. Immunosuppressive doses of cyclosporine abolish the help provided by virgin (primary) TH cells, but allow the priming of normal (and under certain conditions supranormal) numbers of TH cells as assayed by adoptive transfer experiments. The helper function of primed (secondary) TH cells is normally resistant to cyclosporine. However, if T cells are exposed to cyclosporine during priming their helper function remains totally cyclosporine-sensitive as long as the drug therapy is continued. The mechanisms involved in these selective effects are unknown, but the results indicate that in vivo cyclosporine can dissociate effector function (primary help) from TH cell proliferation (priming).