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S Ferrone

Publications and source records attributed to S Ferrone.

At least 55 records · Page 3Linked to original sources
PubMed1999

Increased serum levels of beta2m-free HLA class I heavy chain in multiple myeloma.

Serum levels of beta2-microglobulin (beta2m)-free HLA class I heavy chain (FHC) in 94 patients with multiple myeloma (MM) were higher than in 29 patients with monoclonal gammopathy of undetermined significance (MGUS) (P = 0.023) and in 97 sex- and age-matched healthy controls (P < 0.0001). Spearman correlation analysis indicated that in MM, FHC correlated with beta2m (r = 0.31, P = 0. 003) and the percentage of bone marrow plasma cells (BMPC%) (r = 0. 36, P = 0.002), whereas beta2m, in addition to BMPC% (r = 0.43, P = 0.0003), also correlated with creatinine levels (r = 0.63, P < 0.0001), haemoglobin levels (r = -0.35, P = 0.0007) and patient age (r = 0.34, P < 0.0011). Furthermore, MM patients with poor prognosis (beta2m >/= 6 mg/l) displayed higher FHC levels than those with a better prognosis (beta2m < 6mg/l) (P < 0.021). At variance from beta2m, these levels were not influenced by renal failure, as indicated by the lack of Spearman correlation of FHC with creatinine concentration and of statistical significance between the median FHC concentration of MM patients with creatinine < 176.6 micromol/l and those with creatinine >/= 176.6 micromol/l (P = 0.3). Stratification of patients according to disease activity and stage showed that FHC levels were only statistically different (P = 0.04) for disease activity, whereas beta2m and C-reactive protein were not. Taken together, our data indicate that serum FHC may be a useful disease marker in MM.

Aged↗
PubMed1999

Specific lysis of melanoma cells by receptor grafted T cells is enhanced by anti-idiotypic monoclonal antibodies directed to the scFv domain of the receptor.

Malignant transformation of melanocytes is frequently associated with abnormalities in antigen processing and in human leukocyte antigen class I antigen expression. Here, we evaluated a human leukocyte antigen class I antigen-independent approach to target cytotoxic T lymphocytes to melanoma cells by grafting cytotoxic T lymphocytes with a chimeric receptor that consists of both a domain binding to high molecular weight-melanoma associated antigen and a cellular activation domain. The binding domain is a single-chain antibody fragment (scFv) derived from the monoclonal anti-high molecular weight-melanoma associated antigen antibody 763.74 by phage display techniques. The cellular activation domain is the signaling unit of the FcepsilonRI receptor gamma chain. Both domains constitute the chimeric receptor scFv763.74-gammaR. Cytotoxic MD45 T cells grafted with the scFv763.74-gammaR receptor bind specifically to high molecular weight-melanoma associated antigen-positive melanoma cells and lyse melanoma cells in a human leukocyte antigen class I independent fashion. Pre-incubation of receptor grafted T cells with immobilized anti-idiotypic (id) monoclonal antibody MK2-23 binding to the scFv domain of the receptor enhanced the lysis of melanoma cells indicating that the specific cytolytic activity of receptor grafted T cells can be increased by costimulation with cross-linked anti-idiotypic monoclonal antibodies that recognize the antigen binding domain of the chimeric receptor.

Amino Acid Sequence↗
PubMed1998

HLA (A*0201) mimicry by anti-idiotypic monoclonal antibodies.

Soluble MHC Ags and anti-Id (anti-anti-MHC) Abs have both been shown to inhibit MHC alloantigen-specific B cell responses in vivo. We hypothesized that some anti-idiotypic Abs function as divalent molecular mimics of soluble HLA alloantigen. To test this idea, we studied two well-defined anti-idiotypic mAbs, T10-505 and T10-938, elicited in syngeneic BALB/c mice by immunization with CRll-351, an HLA-A2,24,28-specific mAb. Each anti-Id induced "Ab-3" Abs in rabbits that cross-reacted with HLA-A2 but not with HLA-B Ags. Furthermore, each anti-Id could bind to and block Ag recognition by Ha5C2.A2, a human homologue of mAb CRll-351. Both anti-Id mAb displayed weak reactivity with the human mAb SN66E3, which recognized an overlapping but distinct determinant of HLA-A2 Ags; neither reacted with human mAb MBW1, which recognized a nonoverlapping HLA-A2 determinant. Amino acid sequence comparison of mAb CRII-351 heavy and light chain variable region complementarity-determining regions (CDRs) with those of mAb Ha5C2.A2 and SN66E3 revealed short regions of homology with both human mAb; a large insert in the light chain CDR1 of mAb SN66E3 distinguished it from both CRll-351 and Ha5C2.A2. The amino acid sequences of mAb T10-505 and T10-938, which differed markedly from each other, revealed no homology to the alpha2 domain sequence of HLA-A*0201 that contains the CRll-351 mAb-defined epitope. We conclude that structurally different anti-Id Abs can mimic a polymorphic conformational epitope of an HLA Ag. In the case of T10-505 and T10-938 mimicry was not based on exact replication of the epitope by the hypervariable loops of the anti-Id mAb.

Alleles↗
PubMed1998

Improved tumor targeting of rhenium-186-labeled anti-human high-m.w. melanoma-associated antigen monoclonal antibody 763.74 following purification with anti-idiotypic monoclonal antibody MK2-23.

Because of its high-energy beta emissions and imageable gamma emissions, 186Re represents an attractive isotope to radiolabel monoclonal antibodies (MAbs) recognizing human tumor-associated antigens (TAAs) for radioimmunoscintigraphy (RIS) and radioimmunotherapy (RIT) of patients with malignant diseases. Application of 186Re, however, is hindered by the frequent denaturation of MAbs following exposure to the strong reducing conditions employed in the labeling procedures. To overcome this problem, we have utilized a direct labeling procedure and combined it with affinity chromatography over columns of immobilized anti-idiotypic (anti-id) MAbs which recognize idiotopes in the antigen-combining site of the radiolabeled MAb. The validity of the procedure was demonstrated with the anti-high-m.w. melanoma-associated antigen (HMW-MAA) MAb 763.74 and its corresponding anti-id MAb MK2-23. Utilizing this approach, MAb 763.74 was labeled to specific activities of 2.8 +/- 0.6 mCi/mg with 186Re. Furthermore, its immunoreactivity, which was reduced to about 30% following labeling with 186Re, was improved to about 50% by affinity chromatography over columns of anti-id MAb MK2-23. The improvement in immunoreactivity of 186Re MAb 763.74 resulted in a significant (p < 0.05) increase in targeting to human melanoma tumors grown in nude mice and an increase in sensitivity of RIS. Our results suggest that direct labeling of anti-TAA MAb with 186Re coupled with purification over affinity columns of anti-id MAb may facilitate the application of 186Re to RIS and RIT.

Animals↗
PubMed1998

Limited diversity of human scFv fragments isolated by panning a synthetic phage-display scFv library with cultured human melanoma cells.

To broaden the specificity of the Abs recognizing human melanoma-associated Ags (MAAs), we have isolated human single-chain fragment of the V region (scFv) fragments by panning the synthetic phage Ab library (#1) with the human melanoma cell lines S5 and SK-MEL-28. All of the isolated scFv fragments reacted with the mouse mAb defined high molecular weight melanoma-associated Ag (HMW-MAA). scFv #70 immunoprecipitates the two characteristic subunits of HMW-MAA, while scFv #28 only immunoprecipitates its large subunit. These results challenge the current view regarding the structure of HMW-MAA and indicate that it consists of two independent subunits. The human scFv fragments share some similarities with the mouse anti-HMW-MAA mAb. Like mAb 149.53 and 225.28, scFv #28 reacts with rat B49 neural cells that express a homologue of HMW-MAA. scFv #70 reacts with a determinant that is spatially close to the one identified by mAbs 149.53, VT68.2, and VT86. Besides suggesting similarities in the recognition of human melanoma cells by the mouse and human Ab repertoire, these results indicate that the Abs isolated from synthetic Ab libraries resemble those that are found in natural Ab repertoires. The restricted diversity of the scFv fragments that were isolated by panning synthetic Ab libraries with different melanoma cell lines suggests that certain Ags, like HMW-MAA, are immunodominant in vitro. This phenomenon, which parallels the in vivo immunodominance of certain Ags, implies that the antigenic profile of the cells used for panning determines the specificity of the preponderant population of isolated Abs.

Animals↗
PubMed1998

Different requirements for signal transducer and activator of transcription 1alpha and interferon regulatory factor 1 in the regulation of low molecular mass polypeptide 2 and transporter associated with antigen processing 1 gene expression.

The components of the antigen processing machinery, low molecular mass polypeptide (LMP) 2 and transporter associated with antigen processing (TAP) 1, are encoded by closely linked genes within the major histocompatibility complex class II subregion. Although the two genes share a bi-directional promoter, LMP2 and TAP1 have differential cellular expression. TAP1 is expressed constitutively. However, LMP2 expression requires induction by interferon-gamma in most cells. The regulatory elements within the LMP2/TAP1 promoter and the transcription factors that bind these elements have been defined. However, how these transactivators regulate differential TAP1 and LMP2 gene transcription is not known. We have addressed this question by analyzing three human melanoma cell lines with distinct phenotypes of LMP2 and TAP1 expression. Whereas binding of either interferon regulatory factor 1 or Stat1 to the overlapping interferon consensus sequence-2/GAS is sufficient for regulating transcription of the TAP1 gene, binding of both factors is required for LMP2 gene transcription. This conclusion is supported by restoration of LMP2 gene transcription following transfection of wild type Stat1alpha or interferon regulatory factor 1 cDNA into cells lacking these transcription factors. The flexibility in the regulation of the TAP1 gene may reflect its role in maintaining immune surveillance. Furthermore, lack of LMP2 gene transcription in quiescent human cells suggests that LMP2 expression reflects a state of cell activation.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

beta2-Microglobulin mutations, HLA class I antigen loss, and tumor progression in melanoma.

The potential negative impact of HLA class I antigen abnormalities on the outcome of T cell-based immunotherapy of melanoma has prompted us to investigate the mechanisms underlying lack of HLA class I antigen expression by melanoma cell lines Me18105, Me9923, and Me1386. Distinct mutations in the beta2-microglobulin (beta2m) gene were identified in each cell line which result in loss of functional beta2m. In Me18105 cells, an aberrant splicing mechanism caused by an A--> G point mutation in the splice acceptor site of intron 1 of the beta2m gene, deletes 11 bp from the beta2m mRNA creating a shift in the reading frame. In Me9923 cells a 14-bp deletion in exon 2 and in Me1386 cells a CT deletion in exon 1 of the beta2m gene produce a frameshift mutation. The beta2m gene mutations identified in Me18105, Me9923, and Me1386 cells were also detected in the surgically removed melanoma lesions from which the cell lines originated. Transfection of each melanoma cell line with a wild-type beta2m gene restored HLA class I antigen expression and, in Me18105 cells, recognition by Melan-A/MART-1-specific, HLA-A2-restricted cytotoxic T lymphocytes. Interestingly, the beta2m mutation present in Me9923 cells that were derived from a metastatic lesion was also found in the Me9923P cell line that originated from the autologous primary lesion. These data suggest that beta2m mutations in melanoma cells may be an early event in progression to the malignant phenotype.

Amino Acid Sequence↗
PubMed1998

Characterization of human anti-high molecular weight-melanoma-associated antigen single-chain Fv fragments isolated from a phage display antibody library.

The human high molecular weight-melanoma-associated antigen (HMW-MAA) meets the criteria to be used as an immunogen for immunotherapy of malignant melanoma, because it is expressed by a large percentage of melanoma lesions with limited heterogeneity and has a restricted distribution in normal tissues. The high immunogenicity of the HMW-MAA in BALB/c mice has resulted in the development of a large number of anti-HMW-MAA monoclonal antibodies (mAbs). In contrast, no human anti-HMW-MAA mAbs have been described. Because the latter may serve as useful probes to characterize the antigenic profile of the HMW-MAA, human anti-HMW-MAA single-chain fragments of the variable region (scFvs) were isolated by panning synthetic scFv library 1 on purified HMW-MAA. Colony hybridization studies and nucleotide sequence analysis revealed that scFv 19, 44, 56, and 61 belong to the V(H)3 gene family and use the DP-38 germ-line gene segment but have a diverse third complementarity-determining region. The human scFvs share some characteristics with mouse anti-HMW-MAA mAb but also display some distinct features. Like mouse mAbs, human scFvs recognize determinants of HMW-MAA with a heterogeneous cellular and molecular distribution in human melanoma cells. Furthermore, like some mouse mAbs, human scFvs react with rat neural cells expressing the chondroitin sulfate proteoglycan NG2, which shows 81% homology to the HMW-MAA. However, at variance with mouse mAbs, the human scFvs show poor reactivity with guinea pig melanoma cells. Lastly, human scFv 61 stains both benign and malignant lesions of melanocytic origin, although with a lower frequency than mouse mAbs. Analysis of the clinical significance of the differential expression of the scFv 61-defined determinant in melanoma lesions will be facilitated by its reactivity with formalin-fixed melanoma lesions. In contrast to mouse mAb, scFv 61 immunoprecipitates the >450-kDa chondroitin sulfate proteoglycan component of the HMW-MAA, but not its 250-kDa subunit from melanoma cells. Thus, contrary to the current view about the structure of HMW-MAA, our results demonstrate that the two components are not associated. The described scFv antibodies, which represent the first example of human anti-HMW-MAA antibodies, have provided novel information about the structure of this antigen. Future studies will assess the impact of these in vitro-assembled antibody fragments on the identification of antigenic determinants of the HMW-MAA that can be recognized by the human immune system.

Animals↗
PubMed1998

Molecular analysis of the HLA-A2 antigen loss by melanoma cells SK-MEL-29.1.22 and SK-MEL-29.1.29.

Due to the potential clinical relevance of HLA class I antigen losses in melanoma cells and the scanty information about the molecular mechanisms underlying these defects, we have characterized the cause of the HLA-A2 antigen loss by autologous melanoma cell lines SK-MEL-29.1.22 and SK-MEL-29.1.29. Both cell lines have structural defects of HLA-A2 genes, which cause lack of their transcription. In SK-MEL-29.1.22 cells the 5'-flanking region, exon 1, intron 1, and a region at the 5' end of exon 2 of the HLA-A2 gene are deleted. The breakpoint of the HLA-A2 gene, which is recombined with a DNA fragment of unknown origin, was localized between two GTTCG sequence repeats at position 101 of exon 2. These repeats may provide the sequence basis for misalignment in the process of DNA deletion. In SK-MEL-29.1.29 cells, loss of HLA-A2 antigens, as well as of HLA-B44 and HLA-Cw5 alleles, is caused by the loss of one copy of chromosome 6. Down-regulation of the expressed HLA class I alleles in the two HLA-A2 loss variants and in the parental cells was found to be associated with a low TAP1 expression and a reduced function of peptide transporters. Therefore, multiple defects result in loss or down-regulation of HLA class I alleles in SK-MEL-29.1.22 and SK-MEL-29.1.29 melanoma cells.

Antigens, Neoplasm↗
PubMed1998

HLA class I antigen and transporter associated with antigen processing (TAP1 and TAP2) down-regulation in high-grade primary breast carcinoma lesions.

Five specimens of normal mammary tissue and 53 primary breast carcinoma lesions were tested for expression of HLA antigens and components of the antigen-processing machinery by immunohistochemical staining. The expression of transporter associated with antigen processing (TAP) 1, TAP2, and HLA class I antigens in breast carcinoma lesions was significantly associated with tumor grading. Like normal mammary tissue, the 16 low-grade (G1) breast carcinoma lesions showed strong staining for TAP1, TAP2, and HLA class I antigens. In contrast, only 12 (32%) of 37 high-grade (G2 and G3) breast carcinoma lesions displayed the normal staining pattern. In 14 (38%) of 37 high-grade lesions, HLA class I antigen down-regulation was observed without loss of low molecular mass polypeptide and/or TAP staining. Congruent down-regulation of HLA class I antigen and TAP1 or TAP2 was found in 8 (22%) of 37 high-grade lesions. Complete loss of HLA class I antigens, TAP1, and TAP2 was observed in 3 (8%) of 37 high-grade lesions. No lesion was negative for TAP1 and/or TAP2 staining while positive for HLA class I antigen staining. These data demonstrate an association of HLA class I antigen and TAP down-regulation with tumor progression in breast carcinoma. This association suggests that loss of HLA and/or TAP may represent an escape from the host's immune pressure or may reflect the accumulation of abnormalities associated with neoplastic progression. This accumulation of defects in antigen processing and presentation may in turn be responsible for reduced recognition of malignant cells by putative clinically relevant tumor-specific T cells.

ATP-Binding Cassette Transporters↗
PubMed1998

Induction and functional characterization of beta2-microglobulin (beta2-mu)-free HLA class I heavy chains expressed by beta2-mu-deficient human FO-1 melanoma cells.

The frequent loss of beta2-microglobulin (beta2-mu) in malignant cells has stimulated interest in the functional characteristics of beta2-mu-free HLA class I heavy chains, since this information contributes to assess the impact of beta2-mu abnormalities on the interaction of malignant cells with immune cells. Therefore, the present study has investigated the ability of beta2-mu-free HLA class I heavy chains to modulate NK cell-mediated lysis of melanoma cells and to present melanoma-associated antigen (MAA)-derived peptides to HLA class I-restricted, MAA-specific cytotoxic T lymphocytes (CTL). Beta2-mu-free HLA class I heavy chains were induced on beta2m null FO-1 cells by sequential incubation with IFN-alpha for 48 h at 37 degrees C and for 24 h at 26 degrees C. Transfection of cells with a wild-type H-2Ld gene (FO-1Ld) enhanced the induction of beta2-mu-free HLA class I heavy chains under such experimental conditions. Beta2-mu-free HLA class I heavy chains expressed on the cell membrane did not protect the B2m null FO-1 cells from NK cell-mediated lysis. Furthermore, FO-1 cells which express beta2-mu-free HLA-A2 heavy chains following transfection with a wild-type HLA-A2 gene were not lysed by HLA-A2-restricted, MAA-specific CTL lines and clones. These results indicate that association with beta2-mu is required for interaction of HLA class I molecules with NK inhibitory receptors and for peptide presentation to CTL.

Antigens, Neoplasm↗
PubMed1998

Wide tissue distribution of axolotl class II molecules occurs independently of thyroxin.

Unlike most salamanders, the Mexican axolotl (Ambystoma mexicanum) fails to produce enough thyroxin to undergo anatomical metamorphosis, although a "cryptic metamorphosis" involving a change from fetal to adult hemoglobins has been described. To understand to what extent the development of the axolotl hemopoietic system is linked to anatomical metamorphosis, we examined the appearance and thyroxin dependence of class II molecules on thymus, blood, and spleen cells, using both flow cytometry and biosynthetic labeling followed by immunoprecipitation. Class II molecules are present on B cells as early as 7 weeks after hatching, the first time analyzed. At this time, most thymocytes, all T cells, and all erythrocytes lack class II molecules, but first thymocytes at 17 weeks, then T cells at 22 weeks, and finally erythrocytes at 26-27 weeks virtually all bear class II molecules. Class II molecules and adult hemoglobin appear at roughly the same time in erythrocytes. These data are most easily explained by populations of class II-negative cells being replaced by populations of class II-positive cells, and they show that the hemopoietic system matures at a variety of times unrelated to the increase of thyroxin that drives anatomical metamorphosis. We found that administration of thyroxin during axolotl ontogeny does not accelerate or otherwise affect the acquisition of class II molecules, nor does administration of drugs that inhibit thyroxin (sodium perchlorate, thiourea, methimazole, and 1-methyl imidazole) retard or abolish this acquisition, suggesting that the programs for anatomical metamorphosis and some aspects of hemopoietic development are entirely separate.

Ambystoma↗
PubMed1998

Evaluation of biotinylated cells as a source of antigens for characterization of their molecular profile.

Biotinylated lymphoid cells have been suggested as a useful source of antigen for the immunochemical characterization of their molecular profile. Labelling with biotin eliminates the problems associated with the use of radioactivity. However, this method has not been widely used. This reflects: (1) difficulties in optimizing the signal/background ratio because of the lack of a simple method to quantify biotinylated proteins in a cell lysate, (2) the loss of reactivity with monoclonal antibody of antigen following biotinylation, because of steric hindrance, and (3) the lack of information about the utility of other biotinylated cells as an antigen source. To overcome these limitations, we developed an ELISA to quantify biotinylated proteins in cell lysates and optimized the signal/background ratio. The validity of this approach was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of a number of cell surface antigens immunoprecipitated from lymphoid cells by an optimal amount of monoclonal antibody. Furthermore, we showed that biotinylated melanoma cells are a useful source of antigen for immunoprecipitation experiments and that ligation of biotin to antigen does not affect reactivity with monoclonal antibody. Lastly, biotinylated antigens in cell lysates stored at -80 degrees C for 6 months maintained their reactivity with monoclonal antibodies. Biotinylated cells thus represent a useful source of antigen for characterizing the immunochemical profile and analyzing the specificity of antibodies with immunochemical methods.

Antibodies, Monoclonal↗
PubMed1998

Negative signaling by anti-HLA class I antibodies is dependent upon two triggering events.

mAb with specificity for the alpha3 domain of HLA class I antigens, such as mAb TP25.99 and W6/32, are capable of inhibiting the proliferation of stimulated T cells in vitro by binding to their surface HLA class I antigens. The inhibitory potential of another HLA class I alpha3 domain-specific mAb, A1.4, was evaluated. In contrast to mAb TP25.99 and W6/32, which routinely inhibited superantigen (SEB) stimulation of T cells by >90%, mAb A1.4 at equivalent concentrations demonstrated only 20-50% inhibition. Univalent Fab fragments of all three mAb lacked inhibitory activity. Interestingly, however, by combining univalent W6/32 (or TP25.99) Fab fragments with intact, bivalent mAb A1.4 (at a non-inhibitory, sub-threshold concentration of 1 microg/ml), significant inhibition of SEB-driven T cell proliferation was obtained. Inhibition by the anti-HLA class I mAb W6/32 and TP25.99 was evident even when SEB was used in conjunction with paraformaldehyde-fixed HLA class I-, class II+ Daudi cells, suggesting that the inhibitory activity of these mAb results from direct HLA class I epitope engagement on the T cell. These findings suggest that effective antibody-mediated induction of the HLA class I inhibitory pathway within T cells is dependent upon two separable molecular triggers at the T cell surface. The first can be delivered by univalent mAb derivatives that engage one or more critical HLA class I epitope(s). The second requires intact mAb, though seems to be less selective as to the HLA class I specificity. This model may explain why some, but not all, anti-HLA class I mAb are inhibitory when used singly. Achieving synergies between a wider array of anti-HLA class I mAb and their derivatives may provide a path for more effectively tapping into the HLA class I inhibitory pathway in a therapeutic context.

Animals↗
PubMed1998

Development and characterization of mouse anti-human LMP2, LMP7, TAP1 and TAP2 monoclonal antibodies.

Low molecular mass polypeptides (LMP) 2 and LMP7 and transporter associated with antigen processing (TAP) subunits TAP1 and TAP2 play a crucial role in antigen processing and cell surface expression of HLA class I molecules. Since monoclonal antibodies (mAb) to these molecules will facilitate the analysis of their expression, structure and function in normal and transformed cells, in the present study we have developed these reagents. Specifically anti-LMP2 and LMP7 mAb were generated from BALB/c mice immunized with specific peptides, and anti-TAP1 and TAP2 mAb from BALB/c mice immunized with respective recombinant proteins. mAb VF101-39F7 and VF101-39G5 were shown to be specific for LMP2, mAb VF103-5D5 and VF103-8C2 for LMP7, mAb VF108-1B3 and VF108-12D6 for TAP1 and mAb VF118-1E4 and VF118-2C5 for TAP2, since they reacted specifically with the corresponding immunogens in ELISA and with the corresponding LMP and TAP subunits when tested in Western blotting with human lymphoid cell extracts. Furthermore, the mAb immunoprecipitated components with the characteristic electrophoretic mobility from lymphoid cells. Both anti-LMP and anti-TAP mAb stained keratinocytes and infiltrating lymphocytes in frozen and formalin-fixed, paraffin embedded sections of normal skin in indirect immunoperoxidase reactions. Furthermore, all the mAb except mAb VF103-5D5 stained the cytoplasm of lymphoid cells in an intracytoplasmic staining reaction. The specificity and reactivity pattern of the mAb we have characterized indicate that they will be valuable reagents to analyze the cellular expression and tissue distribution of LMP and TAP subunits.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

Increased level of serum HLA class I antigens in patients with systemic lupus in patients with systemic lupus erythematosus. Correlation with disease activity.

The level of soluble beta2-mu-associated HLA Class I heavy chains (sHLA-I) and of soluble beta2-mu-free HLA Class I heavy chains (sHLA-FHC) was found to be significantly higher in sera from 58 patients with systemic lupus erythematosus (SLE) than in those from 82 age and sex-matched controls. The level of serum sHLA-I in patients with SLE was significantly correlated to disease activity. Western blotting analysis showed that the 44-kDa isoform represents the major component in the antigens immunoprecipitated by anti-beta2-mu mAb NAMB-1 and by anti-beta2-mu-free HLA Class I heavy chain mAb HC-10 from sera of patients with SLE. These results suggest that the increased serum levels of sHLA-I and of sHLA-FHC in patients with SLE reflect their increased shedding from cell membrane. In view of the ability of sHLA-I and of sHLA-FHC to induce apoptosis of activated T cells, it is suggested that their increased serum levels in patients with SLE is triggered by dysregulation of the immune system leading to T-cell activation. The increased serum levels of sHLA-I and of sHLA-FHC may be used by the immune system to control the pool of activated T cells by inducing apoptosis. If this possibility is proven to be correct, modulation of the serum level of sHLA-I and of sHLA-FHC may be utilized to develop strategies to treat SLE.

Adolescent↗
PubMed1997

Clinical significance of alpha(v)beta3 integrin and intercellular adhesion molecule-1 expression in cutaneous malignant melanoma lesions.

Several lines of experimental evidence in in vitro and animal model systems suggest that the integrin alpha(v)beta3 plays a role in the tumorigenicity of human melanoma cells and that the blocking of alpha(v)beta3 ligand binding can inhibit tumor progression. However, there is only scanty information about the role of alpha(v)beta3 in malignant melanoma in a clinical setting. Therefore, in the present study, we have analyzed the distribution in lesions of melanocyte origin and in normal tissues of the alpha(v) integrin subunit and of the alpha(v)beta3 complex and their association with histopathological and clinical parameters of malignant melanoma. We have used as probes the monoclonal antibodies (mAbs) TP36.1 and VF27.263.15, which we have shown with a combination of serological and immunochemical assays to be specific for the alpha(v) subunit and for the alpha(v)beta3 complex, respectively. In immunohistochemical assays, mAb TP36.1 stained both benign and malignant lesions of melanocyte origin. In contrast, the reactivity of mAb VF27.263.15 was restricted to malignant lesions. Both mAbs displayed differential reactivity with primary melanoma lesions of different histotypes because they stained about 50% of acral lentiginous melanoma and superficial spreading melanoma lesions, at least 80% of nodular melanoma lesions, and none of the uveal melanoma lesions tested. Both mAbs TP36.1 and VF27.263.15 stained about 60% of lymph node metastases and 80% of cutaneous metastases. Expression of the alpha(v)beta3 complex in melanocytic lesions resembles that of intercellular adhesion molecule-1 (ICAM-1) in several respects: (a) both are expressed in a significantly (P < 0.004) larger proportion of malignant than of benign lesions; (b) expression of both molecules in primary melanoma lesions is significantly (P < 0.05) associated with lesion thickness; and (c) expression of both molecules in primary lesions from patients with stage I melanoma is significantly (P < 0.05) associated with an increased probability of disease recurrence following surgical excision. alpha(v)beta3 and ICAM-1 in primary melanoma lesions complement each other in predicting the outcome of the disease, because the association with prognosis was enhanced when primary lesions were stained by both anti-alpha(v)beta3 mAb VF27.263.15 and anti-ICAM-1 mAb CL203.4 or by neither mAb. Because alpha(v)beta3 has been suggested as a potential target of immunotherapy, its distribution in normal tissues was investigated. alpha(v)beta3 expression is restricted because it was only detected in ductal epithelium of parotid glands, thyrocytes, basal glands of the stomach, colonic and rectal epithelium glomeruli, Bowman's capsules and proximal and distal tubules of kidneys, and endometrial epithelium. These findings suggest that renal function will be a critical clinical parameter to monitor in therapies of malignant diseases relying on systemic administration of anti-alpha(v)beta3 mAb.

Antibodies, Monoclonal↗