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L Fainboim

Publications and source records attributed to L Fainboim.

At least 37 records · Page 2Linked to original sources
PubMed1999

A novel hydrophobized GM3 ganglioside/Neisseria meningitidis outer-membrane-protein complex vaccine induces tumor protection in B16 murine melanoma.

Gangliosides are sialic acid-containing glycosphingolipids that have increased surface membrane expression on cancers of neuroectodermal origin. The present study was designed to investigate at a preclinical level the therapeutic usefulness of a consistently immunogenic and safe conjugate vaccine in melanoma. We have examined a novel vaccine of GM3 monosialoganglioside hydrophobically conjugated with the outer-membrane-protein complex from Neisseria meningitidis plus Montanide ISA 51 in the B16 melanoma mouse model. B16 cell line is characterized by the predominant presence of ganglioside GM3 on the cell surface. Vaccines were administered i.m. in the quadriceps at 14-day intervals and B16 cells were injected in the subcutis of the right flank of C57BL/6 mice, 7 days after the fourth dose. Significant suppression of tumor growth and prolongation of survival were seen by immunization with GM3 vaccine in animals challenged with 5x10(3) or 10(3) live melanoma cells. In addition, vaccination reduced tumor growth in animals challenged with 5x10(4) cells. The reactivity of serum IgG from vaccinated mice was examined by a sensitive immunoperoxidase assay on B16 tumor specimens. Most melanoma cells displayed a distinct positive staining associated with both cell membrane and cytoplasm. In accordance with the immunohistochemical stainings, the antisera of immunized mice reacted brightly against B16 melanoma cells in flow cytometry studies. Anti-sera also mediated complement-mediated cytotoxicity and specific response could be totally ascribed to antibodies of the IgG2b subclass. The present data suggest that GM3 vaccine may provide a useful immunotherapeutic strategy for melanoma.

Animals↗
PubMed1999

[PCR determination of an association between class II HLA and pemphigus vulgaris].

Pemphigus vulgaris (PV) is an autoimmune blistering disease affecting the skin and mucous membranes. It is characterized by the presence of an autoantibody directed against desmoglein 3, which causes acantholysis and blister formation. In this study, we examined the HLA antigens of 30 caucasian argentinian patients compared with 199 controls. We used the PCR-SSO method (Polymerase Chain Reaction-Sequence Specific Oligonucleotide). We found that PV patients had significantly increased frequencies of HLA DR4 (RR = 3.80, P = 0.001) and HLA DR 14 (RR = 5.97, P = 0.0001). As in other populations, two associated alleles were found: the first was DR beta 1*0402 (RR = 44.70, P = 10.7) and DQ beta 1*0302 (RR = 71.82, P = 10(-7)) and the second was DR beta 1*1401 (RR = 117.94, P = 10(-7)) y DQ beta 1*0503 (RR = 86.95, P = 10(-7)).

Alleles↗
PubMed1998

Interactions of dendritic cells with fibronectin and endothelial cells.

We studied the phenotypic characteristics of spontaneously migrated skin dendritic cells (sDC) and monocyte-derived dendritic cells (moDC), generated under different culture conditions, and their interactions with fibronectin (FN) and endothelial cells. Monocyte-derived dendritic cells were obtained after culturing monocytes with granulocyte-macrophage colony-stimulating factor (GM-CSF) (800 U/ml) and interleukin-4 (IL-4) (500 U/ml) with either 10% fetal bovine serum (FBS) or 10% allogeneic human serum (HS). Regardless of the type of serum used, the majority of moDC expressed human leucocyte antigen-DR (HLA-DR) and CD86. On day 5 of incubation, 20-67% of moDC cultured in the presence of HS (HS-moDC) expressed CD1a, b and c versus 94-97% when cultured in the presence of FBS (FBS-moDC). DC showed a differential gradient of adhesion to FN: FBS-moDC>HS-moDC>sDC approximately monocytes. Both FBS-moDC and HS-moDC were strongly positive for CD49e (alpha5-integrin) and CD29 (beta1-integrin) but negative for CD49d (alpha4-integrin). A monoclonal antibody (mAb) against CD49e blocked the adhesion of both types of moDC to FN. Although both FBS-moDC and HS-moDC attached to endothelium (a 76% and 63% increase, respectively), only HS-moDC were able to migrate through non-activated endothelium. Overall, these results suggest that spontaneously migrated sDC are less adherent to FN than moDC, that HS and FBS induce differences in CD1 expression, that HS-moDC are less adhesive to FN and endothelial cells but more motile than FBS-moDC, and that alpha5beta1-integrin is the molecule involved in moDC adhesion to FN.

Animals↗
PubMed1997

Pattern of cytokine receptors expressed by human dendritic cells migrated from dermal explants.

Different reasons account for the lack of information about the expression of cytokine receptors on human dendritic cells (DC): (a) DC are a trace population; (b) the proteolytic treatment used to isolate DC may alter enzyme-sensitive epitopes; and (c) low numbers of receptors per cell. In the present work the expression of cytokine receptors was analysed by flow cytometry on the population of dermal DC (DDC) that spontaneously migrate from short-term culture dermal explants. DDC obtained after dermal culture were CD1alow, CD1b+, CD1c+, human leucocyte antigen (HLA)-DR+, CD11chigh, CD11b+ and CD32+. The DC lineage was confirmed by ultrastructural analysis. DDC expressed interleukin (IL)-1R type 1 (monoclonal antibody (mAb) hIL-1R1-M1; and 6B5); IL-1R type 2 (mAb hIL-1R2-M22); IL-2R alpha chain (mAb anti-Tac; and hIL-2R-M1) and IL-2R gamma chain (mAb 3B5; and AG14C). DDC did not stain for IL-2R beta chain using four mAbs recognizing two different epitopes of IL-2R beta (mAb 2R-B; Mik-beta 1; and CF1; Mik-beta 3, respectively). DDC were also positive for the cytokine binding chains (alpha chains) of IL-3R (mAb 9F5); IL-4R (mAb hIL-4R-M57; and S456C9); and IL-7R (mAb hIL-7R-M20; and R3434). DDC showed low levels of IL-6R alpha chain (mAb B-F19; B-R6; and B-E23) and its signal transducer gp130 (mAb A2; and B1). DDC strongly expressed interferon-gamma receptor (IFN-gamma R) (mAb GIR-208) and were negative for IL-8R (mAb B-G20; and B-F25). All DDC were highly positive for granulocyte-macrophage colony-stimulating factor receptor (GM-CSFR) alpha chain (mAb hGM-CSFR-M1; SC06; SC04, and 8G6) and to a lesser extent for the common beta chain of GM-CSFR, IL-3R and IL-5R (mAb 3D7). On the other hand, reactivity was not found for granulocyte colony-stimulating factor receptor (G-CSFR) (mAb hGCSFR-M1) nor macrophage colony-stimulating factor receptor (M-CSFR) (mAb 7-7A3-17) confirming the DC lineage of DDC. As previously reported for lymphoid DC, DDC expressed tumour necrosis factor receptort (TNFR) 75000 MW (mAb utr-1; hTNFR-M1; and MR2-1) but lacked TNFR 55000 MW (mAb htr-9; MR1-1; and MR1-2). In summary, DDC express receptors for a broad panel of cytokines, even receptors for cytokines whose effects on DC are still unknown (i.e. IL-2R alpha gamma; IL-6R alpha/gp 130; IL-7R alpha gamma).

Antibodies, Monoclonal↗
PubMed1996

Flow cytometric analysis of cytokine receptors on human Langerhans' cells. Changes observed after short-term culture.

It is well established that granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-1 and tumour necrosis factor-alpha (TNF-alpha) are involved in Langerhans' cell (LC) development and dendritic cell traffic. However, little is known about the pattern of cytokine receptors on human LC and their modulation during different stages of maturation. The expression of cytokine receptors was studied by flow cytometry on both freshly isolated LC (fLC) and 72-hr cultured LC (cLC). Epidermal cell suspensions enriched in LC were obtained after skin trypsinization and Ficoll-Hypaque gradient. LC were identified by their CD1a positivity. Although the majority of fLC were positive for the alpha chain of GM-CSF receptor (GM-CSFR), the beta chain of GM-CSFR was detected only on 15% of CD1a+ cells. fLC were also positive for IL-1 receptor (IL-1R) type 1, IL-1R type 2, 75,000 molecular weight TNF receptor (TNFR) and interferon-gamma receptor (IFN-gamma R). IL-6R and its transducing signal gp130 were present in a subset of fLC. Granulocyte colony-stimulating factor receptor (G-CSFR), macrophage colony-stimulating factor receptor (M-CSFR), the alpha and beta chain of IL-2R, IL-4R, IL-7R, IL-8R and 55,000 molecular weight TNFR were not detected on fLC. After culture, LC up-regulated the expression of both the alpha and beta chains of GM-CSFR, IL-1R type 2, alpha and beta chains of IL-2R, IL-6R and gp130. In contrast, IL-1R type 1 and 75,000 molecular weight TNFR were down-modulated and the expression of IFN-gamma R was not affected by culture. These results suggest that LC undergo changes in the cytokine receptor repertory during in vitro maturation.

Antibodies, Monoclonal↗
PubMed1996

Expression and modulation of C5a receptor (CD88) on skin dendritic cells. Chemotactic effect of C5a on skin migratory dendritic cells.

Although it is known that dendritic cells (DC) migrate in response to inflammatory stimuli. There is little information about the expression of receptors for chemotactic factors on DC. The present study has demonstrated by double immunostaining and flow cytometry of Langerhan's cell (LC)-enriched epidermal cell suspensions that a small subpopulation (5-6%) of epidermal resident DC (rLC) expresses receptors for C5a (C5aR). Epidermal rLC positive for C5aR show a round-shape morphology, were located next to the basement membrane and express HLA-DR molecules higher than C5aR negative rLC. These observations suggest that rLC would express C5aR as part of their process of maturation during tissue trafficking. To investigate whether epidermal LC up-regulate C5aR along their differentiation pathway. LC were differentiated in vitro after culture in epidermal cell suspensions supplemented with granulocyte macrophage colony-stimulating factor (GM-CSF). As a result, in vitro differentiated LC increased the expression of C5aR up to 69% of the DC population. In accordance with this observation, interdigitating DC of secondary lymphoid organs (lymph node and tonsil) also expressed (5aR. Migratory CD1a positive DC that spontaneously migrated out of dermal or split-skin organ explants were also positive for C5aR and were used for chemotaxis and chemokinesis assays in response to human recombinant C5a (rC5a). Optimum migration to rC5a was observed at 10(-8)M with a sigmoidal dose response curve. Checkboard analysis demonstrated that locomotion in response to rC5a was chemotaxis and not chemokinesis.

Antigens, CD↗
PubMed1995

Allelic heterogeneity of HLA-B35 subtypes in different populations as assessed by DNA typing.

HLA-B35, a class I antigen differentially associated to several diseases in different ethnic groups, comprises at least eight alleles which differ among them by one to six amino acids. In the present work a rapid DNA typing procedure was used to investigate the distribution of the various HLA-B35 alleles in different populations. The approach is based on a group-specific PCR amplification of a set of closely related HLA-B alleles sharing a Thr in position 45 of the alpha-1 domain. The amplified DNA was then hybridized to a panel of sequence-specific oligonucleotide (SSO) probes designed to recognize the polymorphic residues in previously reported HLA-B35 subtypes. This methodology was successfully tested in 100 individuals of four different populations, previously typed by serology as HLA-B35, and in six reference panel cells of the 10th International Histocompatibility Workshop. HLA-B*3501 was the predominant subtype in all populations. B*3502, B*3503 and, to a lesser extent B*3508, were also found. Among Mexican Mestizos, thirteen individuals had patterns of SSO hybridization suggestive of new B35 alleles. The evolutionary considerations on the different B35 alleles and their extended B35,Cw4 haplotypes are discussed.

Alleles↗
PubMed1994

Hepatitis B virus antigens in peripheral blood mononuclear cells during the course of viral infection.

We studied the expression of surface (HBsAg) and core (HBcAg) proteins of hepatitis B virus (HBV) on the surface of peripheral blood mononuclear cells (PBMC) from HBV-infected patients. A total of 122 patients with different liver viral diseases was analyzed by indirect immunofluorescence with monoclonal antibodies. The 35 patients with HBV chronic active hepatitis (CAH) and 38 of 60 patients with acute hepatitis B (63%) expressed HBsAg on the PBMC. No expression was detected on the cells from both normal and HBV-unrelated viral hepatitis control groups. Serial follow-up of patients with acute hepatitis B showed that HBsAg expression by PBMC tended to be undetectable 4 months after the onset of the disease and at the same time the clinical improvement was evident. Cell cultures of EBV-transformed B lymphocytes were established from PBMC of HBV-infected patients; immunoelectron microscopy demonstrated the HBsAg on the cellular membrane. One-third of HBV-infected patients who were studied showed the expression of HBcAg by PBMC. HBcAg was detected in patients with acute hepatitis B at the early stage of infection. The cells of these patients also expressed HBsAg in PBMC. In CAH patients, a positive association was observed between the expression of HBcAg and the presence of serum HBeAg.

Acute Disease↗
PubMed1994

Chronic active autoimmune hepatitis in children. Strong association with a particular HLA-DR6 (DRB1*1301) haplotype.

The association of HLA antigens and type I or "lupoid" CAH-C was investigated in a population of 52 Argentinian Caucasoid patients. When compared with a population of normal individuals of the same ethnic group (n = 197), a significant increase of HLA-DR6 was observed (68.6% in patients vs 17.3% in controls; RR = 12.3, chi 2 = 52.4, pc = 0.00001). DNA typing showed that the HLA-DRB1*1301 allele was present in 32 out of 33 HLA-DR6 patients (66.6% of all the C-CAH patients vs 10.5% in controls; RR = 16.2, chi 2 = 111.3, pc = 0.00001). Analysis of HLA-DQB1 alleles also showed a significant increase of DQB1*0603 (RR = 15.4, chi 2 = 106.5, pc = 0.00001), an allele found in strong linkage disequilibrium with DRB1*1301. The association of CAH-C with this particular HLA-DR6 haplotype has not been previously described for the adult onset CAH. This different HLA predisposition, together with the fact that extrahepatic autoimmune diseases occur frequently only in the adult form of the disease, suggest that the immunopathogenic mechanisms involved in the development of these diseases may be different.

Adolescent↗
PubMed1994

Molecular characterization of HLA class II genes in celiac disease patients of Latin American Caucasian origin.

In the present study, the polymorphic domain of HLA class II genes present in a pediatric population of Argentinian celiac disease patients was analyzed by hybridization to sequence-specific oligonucleotides and DNA sequencing. Sixteen out of 16 DR5/7 heterozygous patients bore the DQA1*0501 and DQB1*0201 alleles implicated in the DQ2 risk specificity. The second exon of DQA1, DQB1 and DRB1 genes from 2 DR5/7 patients was characterized by DNA sequencing. The following alleles were found in both patients: DRB1*1101 and DRB1*0701; DQB1*0301 and DQB1*0201; DQA1*0501 and DQA1*0201. Previous serological analysis in this population had shown the presence of DQ2 in 95% of the patients (40% in controls) and a negative association with DQ1 haplotypes, suggesting the presence of other "permissive" or neutral alleles. The following HLA-DQB1 alleles, besides DQB1*0201, were identified in 31 CD patients: DQB1*0301, 0302, 0401 and 0402. All these alleles share a common pattern of residues between positions 84 and 90, and distinct from that present in DQ1-related alleles.

Alleles↗
PubMed1994

Cellular subsets and epithelial ICAM-1 and HLA-DR expression in human papillomavirus infection of the vulva.

Cryostat sections of 20 clinical condylomata of the vulva induced by human papillomavirus and 5 normal control biopsies were examined using immunohistochemistry. The results indicated that in vulvar papillomavirus infection the intraepithelial Langerhans' cells showed abnormal morphology and a significantly lower density than controls. CD1a positive Langerhans' cells were also observed in dermis of condylomata, suggesting an abnormal epithelial traffic of dendritic cells. T lymphocytes with a mean CD4/CD8 ratio of 0.25 and a mean density of 267 +/- 59 cells/mm2 of epithelial section were the main cellular infiltrate in vulvar papillomavirus infection. Most of the T cells were HLA-DR negative. Those condylomata with moderate to severe mononuclear infiltrate showed leucocyte function antigen 1 positive T cells forming small clusters in the lower epithelial half around the ICAM-1 positive keratinocytes. Vulvar warts also showed epithelial areas with overlapped ICAM-1 and HLA-DR expression. Scattered T gamma-delta and B lymphocytes, macrophages and NK cells were observed among the cells of the dermal infiltrate of vulvar condylomata.

Adult↗
PubMed1994

Analysis of hepatitis B surface antigen expression on leucocyte subpopulations by two-color fluorescence with flow cytometry.

We have analyzed the expression of HBsAg on different subpopulations of peripheral blood cells from hepatitis B virus (HBV) infected patients using two-color immunofluorescence and flow cytometry. An average of 7.4 +/- 0.8% and 9.8 +/- 1.2% HBsAg + cells were found among cells from acute and chronic hepatitis B patients, respectively. When studied by two-color immunofluorescence, HBsAg was limited to cells expressing the B-cell restricted antigen CD19 (16.7 +/- 2.4%), whereas for the other subsets studied (CD3+, CD4+, CD8+, CD67+, CD68+) the percentage of positivity was lower than 4%. The expression of viral antigen on B cells might be relevant for a number of functional interactions between HBsAg+ B and T lymphocytes.

Acute Disease↗
PubMed1993

Relationship between types of human papillomavirus and Langerhans' cells in cervical condyloma and intraepithelial neoplasia.

Planimetric and immunohistologic studies of Langerhans' cells were performed on epithelial sheets dissected from paired biopsy specimens removed from histopathologically normal and abnormal areas of cervices infected by the human papillomavirus. The results showed that epithelial lesions associated with human papillomavirus types classically not related to malignancy (such as types 6 and 11) showed a similar decrease in the Langerhans' cell number to that induced by types 16 and 18. This phenomenon was analyzed in condylomas and cervical intraepithelial neoplasia of low degree, in which human papillomavirus DNA was detected by Southern blot. On the other hand, a significant decrease was observed in Langerhans' cell number in areas of condyloma and cervical intraepithelial neoplasia compared to normal (control) areas from the same patients. It was also confirmed that Langerhans' cell density increases along with the grade of intraepithelial neoplasia.

Adult↗
PubMed1992

Cellular and humoural autoimmunity markers in type 2 (non-insulin-dependent) diabetic patients with secondary drug failure.

In some cases patients with Type 2 (non-insulin-dependent) diabetes mellitus fail to respond to treatment with oral hypoglycaemic agents. These patients may respond in the same way as Type 1 (insulin-dependent) diabetic patients. Cellular immune aggression (defined as the capacity of peripheral mononuclear cells to inhibit stimulated insulin secretion by dispersed rat islet cells), insulin autoantibodies, C-peptide response and HLA antigens were determined in 31 Type 2 diabetic patients with secondary failure to oral hypoglycaemic agents and in 22 control subjects. Nine (29.03%) of the 31 Type 2 diabetic patients showed positive cellular immune aggression (2 SD below control group) and 22 (70.97%) presented no cellular immune aggression. There was a relationship between positive cellular immune aggression and each of the following parameters: age, body mass index and microangiopathy. No correlation was found between positive cellular immune aggression and glycaemia, HbA1, blood lipids or atherosclerosis. Patients with positive cellular immune aggression showed a significantly lower glucagon-stimulated C-peptide response vs those with no cellular immune aggression. Within a sub-group of patients who had never been treated with insulin, insulin autoantibodies were present in four of six patients with positive cellular immune aggression. DR2 antigen was found with decreased frequency in patients whereas no DR3/DR4 heterozygotes were observed. Our data support the hypothesis that a group of Type 2 diabetic patients with secondary failure to oral hypoglycaemic agents presented autoimmunity towards pancreatic Beta cells.

Analysis of Variance↗
PubMed1992

Density and distribution of Langerhans cells in the human uterine cervix.

Using a combination of immunohistochemistry and planimetric observation we report the density and distribution of Langerhans cells (LCs) in epithelium from the normal ectocervix and from the normal transformation zone (TZ). The density of LCs increased towards the basement membrane. Dendritic LCs aspect was more prominent in the superficial layers.

Adult↗
PubMed1992

Intracellular expression of CD1 molecules on PHA-activated normal T lymphocytes.

In this study we have analyzed, using immunoperoxidase (IPx) and indirect immunofluorescence (IIF), the intracellular and cell surface expression of CD1 antigens on PHA activated human T cells. By IIF, CD1 isotypes were not detected on the surface of 3 days PHA activated cells. Conversely, CD1a, CD1b and CD1c molecules were found by IPx in the cytoplasm of normal activated cells from 13 different donors. Kinetic studies showed that, while CD25 was already observed 24 h after activation, all 3 isotypes of CD1 molecules started to be detected 48 h after PHA activation, with a peak expression at 72 h.

Antigens, CD↗
PubMed1992

Assessment by planimetry of Langerhans' cell density in penile epithelium with human papillomavirus infection: changes observed after topical treatment.

Langerhans' cells could have an important role in the immune surveillance for the malignant transformation associated with certain viral infections. A planimetric study of Langerhans' cells was performed on epithelial sheets obtained from male and female patients who presented with human papillomavirus-induced condylomata. Preliminary epidemiological studies have indicated that after a human papillomavirus infection the risk of malignant transformation is higher in the cervix than in the penis. Our study was designed in such a way that the Langerhans' cell density observed in condylomata could be compared to that detected in adjacent normal areas from the same patients. The results showed that a highly significant decrease in Langerhans' cells occurred in male and female human papillomavirus infected genital tracts. In the penis the local treatment with 5-fluorouracil restored the normal Langerhans' cell density. The significance of these findings in relationship with malignant transformation is discussed.

Administration, Topical↗