Biomedical subjects

N Hogg

Publications and source records attributed to N Hogg.

At least 181 records · Page 10Linked to original sources

PubMed1986

Macrophage antigens and the effect of a macrophage activating factor, interferon-gamma.

Molecules characteristic of mononuclear phagocytes have been identified using monoclonal antibodies (MAb). MAb 3.9 reacts with a 150/95 000 dalton heterodimer which is found exclusively on monocytes and macrophages and appears to be the third member of the lymphocyte function-associated (LFA) family of molecules. In contrast, the reactivity of MAb 24, which bonds to a 175 000 dalton protein, is most highly expressed on the macrophages in lymphoid tissue. Both 3.9 and 24 detect the interdigitating cells in the T cell areas of these tissues, which strongly suggests that this cell type belongs to the macrophage family. A third MAb, 10.1, reacts selectively with a set of macrophages outside lymphoid tissue, particularly on Kupffer cells, alveolar macrophages and microglia. Thus subsets of tissue macrophages are proving easy to identify whereas it appears that circulating monocytes are not easily subdivided. None of the MAbs detected either Langerhans' cells, dendritic reticulum cells of B cell areas, or osteoclasts, indicating that these cells are not mononuclear phagocytes. As a first step towards identifying macrophage molecules which have a biological function, we have investigated the effect of macrophage-activating factor, interferon-gamma, on the expression of macrophage membrane molecules. There was greatly increased expression of only two out of ten molecules detected with anti-myeloid antibodies.

Antibodies, Monoclonal↗

PubMed1986

The p150,95 molecule is a marker of human mononuclear phagocytes: comparison with expression of class II molecules.

A new monoclonal antibody (mAb), named 3.9, is described that is specific for the p150,95 molecule, a member of the LFA-1, CR3, p150,95 family of human leukocyte differentiation antigens. The LFA-1 molecule participates in a variety of T cell interactions and the CR3 molecule is the receptor for the complement component iC3b, but little is known about the p150,95 molecule. Here we show that the expression of p150,95 is confined to myeloid cells. mAb 3.9 reacts variably with neutrophils, more strongly with monocytes and is most strongly expressed on tissue macrophages. Using this mAb and others, we have examined the heterogeneity of tissue macrophages. Cells such as Langerhans' cells, dendritic reticulum cells and osteoclasts failed to react with these mAb and thus, probably do not belong to the mononuclear phagocyte lineage. Using a new double-labeling technique, we investigated lymphoid tissue for dendritic cells bearing class II molecules which might function in interactions with T cells. In T cell areas macrophages expressing class II markers were seen but there was no evidence for other types of dendritic or interdigitating cells which expressed class II molecules but not macrophage epitopes. The conclusion from this survey was that the most prominent cell with dendritic morphology found in the T cell areas of lymphoid tissue was a macrophage.

Antibodies, Monoclonal↗

PubMed1986

Ligand binding by the p150,95 antigen of U937 monocytic cells: properties in common with complement receptor type 3 (CR3).

U937 cells (a monocytic cell line) grown in the presence of phorbol myristate acetate were surface labeled with 125I and the iC3b-binding proteins isolated by affinity chromatography on iC3b-Sepharose in the presence of divalent cations. Three polypeptides of 170, 150 and 95 kDa were found to bind specifically to iC3b-Sepharose. The polypeptides of 170 and 95 kDa were identified as the alpha and the beta subunits of CR3 by immunoprecipitation with OKM1 monoclonal antibody. The 150-kDa polypeptide was not immunoprecipitated by antibodies to the alpha subunit of CR3 or LFA-1. However, the 150-kDa polypeptide, together with the 95-kDa polypeptide, was immunoprecipitated with an anti-beta subunit-specific antibody IB4, which immunoprecipitates LFA-1, CR3 and p150,95. These results indicated that the 150-kDa polypeptide is the alpha subunit of the p150,95 antigen. The binding of p150,95 and CR3 to iC3b-Sepharose is specific as neither binds to C3u-Sepharose. A monoclonal antibody, 3.9, which immunoprecipitated the 150 and a 95-kDa polypeptide from U937 cells was characterized as being directed against the alpha-subunit of the p150,95 antigen. Phorbol myristate acetate-stimulated U937 cells from rosettes with EAC3b and EAiC3b but not with EAC3d cells. Monoclonal antibody 3.9 does not inhibit either type of rosetting, but we were unable to exclude a role for p150,95 in adherence of iC3b-coated particles. Since there is no rosetting with C3d-bearing particles it is unlikely that p150,95 is a receptor for C3d, a role for p150,95 which has been suggested by others (Wright, S.D., Licht, M.R. and Silverstein, S.C., Fed. Proc. 1984. 43: 413).

Antibodies, Monoclonal↗

PubMed1986

Lymphocytes, polymorphonuclear leukocytes, macrophages and platelets in synovium involved by rheumatoid arthritis. A study with monoclonal antibodies.

The inflammatory cell infiltrate involving synovial tissues from joints affected by rheumatoid arthritis (RA)++ has been contrasted with that present in synovium removed from joints involved by previous trauma (T) or osteoarthritis (OA). Cell deployment has been mapped by immunohistochemistry using monoclonal antibodies which recognise epitopes characterising T and B cells, polymorphonuclear leukocytes, mononuclear phagocytes and platelets. Mononuclear phagocytes were the most consistent feature of the rheumatoid inflammatory cell exudate and were present, particularly in the synovial layer, in all OA/T samples. The synovial cells lacked the C3b complement receptor, CR1, but expressed CR3, the receptor for C3bi. In rheumatoid synovium, interdigitating cells were difficult to identify but cells of dendritic morphology bore at least one macrophage epitope. T cells far out-numbered B cells and generally lacked the IL-2 receptor which is an indicator of T cell activation. Care is required in the estimation of the T helper/inducer (TH) T suppressor/cytotoxic (Ts) ratio. Polymorphonuclear leukocytes were demonstrated around vessels and near the synovial intimal cell layer suggesting rapid tissue transit. Extravascular platelets were sparse. Follicular dendritic cells were defined by their central location in lymphoid follicles and strong expression of CR1 receptors. HLA-DR expression was widespread except on endothelial cells.

Aged↗

PubMed1985

An anti-human monocyte/macrophage monoclonal antibody, reacting most strongly with macrophages in lymphoid tissue.

In this report, we have described monoclonal antibody (mAb) 24 which bound specifically to a 174,000 polypeptide present on 45 +/- 16% of human monocytes. Expression of the 24 molecule increased on monocytes when they were cultured. When tissues were examined using immunohistochemical techniques, macrophages (Mph) associated with skin and with lymphoid organs strongly expressed the mAb 24 molecule, whereas, Mph in nonlymphoid organs were only weakly positive. mAb 24 reacted with cells of Mph morphology plus cells of interdigitating appearance in T-cell areas, suggesting that these cells might belong to the Mph cell lineage. There was no reaction with other types of cells, such as Langerhans cells, osteoclasts, dendritic reticulum cells, and endothelial cells. The fact that the molecule recognised by mAb 24 is particularly associated with Mph in lymphoid tissue suggests that it might have a function in immune responses.

Antibodies, Monoclonal↗

PubMed1985

Mononuclear phagocytes of normal and rheumatoid synovial membrane identified by monoclonal antibodies.

The presence of cells bearing epitopes of the mononuclear phagocyte series was studied immunohistochemically in synovium removed from joints involved by trauma (T), osteoarthritis (OA) and rheumatoid arthritis (RA). Mononuclear phagocytes were the most consistent feature of the inflamed rheumatoid synovium. They shared at least five epitopes expressed by mononuclear phagocytes in other tissues. In OA/T samples, cells bearing markers of the less mature monocyte were present at the surface of the synovial membrane, namely the intimal layer, while those bearing macrophage epitopes were apparent throughout the intimal layer and subintimally. This suggested that maturation of the monocyte population takes place after the monocytes have entered the synovial tissues, settled at the surface, then moved downward into the subintimal layer. The synovial monocytes accounted for all the HLA-D region positive cells in the lining layer.

Adult↗

PubMed1985

Features of synovial membrane identified with monoclonal antibodies.

As part of a study of the characteristics of the synovial membrane which make it susceptible to inflammatory reactions, we tested a number of monoclonal antibodies (MoAb) which revealed novel features of the synovium using tissue from rheumatoid, osteoarthritic and traumatized (mechanically deranged) joints. In a previous study we detected macrophages (Mph) lining the synovial membrane by means of Mph specific and HLA-DR specific MoAb. These may account for the type A synoviocytes. Type B synoviocytes are thought to be fibroblastic and we used an anti-Thy 1 MoAb to identify these cells. Many fibroblasts were seen in a subintimal position but only few in the lining layer, not in sufficient numbers to account for the type-B category of synoviocyte. Staining with a new MoAb, 67, was found to precisely delineate the lining layer. This MoAb was previously seen to react with dendritic reticulum cells (DRC) of germinal centres, cells involved in B lymphocyte activation. However, other MoAb which react with germinal centre DRC did not label the synovial lining layer. Several MoAb revealed features of the vasculature not previously recognized. In rheumatoid samples, MoAb10 labelled small capillaries near the synovial surface and larger vessels deeper in the intima were labelled with a second MoAb, SM phi. This dichotomy of staining was not so apparent in synovium from control osteoarthritis and trauma (OA/T) samples. In addition, the Thy 1 epitope, identified previously on a variety of human cells, was strongly expressed on all vascular endothelium. Finally a new vessel or duct like structure was identified in OA/T samples, located subintimally. These ducts contained keratin, detected with MoAb LE61 and may be the normal counterpart for the rare malignancy, biphasic synovial sarcoma.

Adult↗

PubMed1985

Monocytes and other infiltrating cells in human colorectal tumours identified by monoclonal antibodies.

Monoclonal antibodies have been used to examine the patterns of infiltrating cells in colorectal tumours staged according to Dukes' classification. MAbs reacting with monocytes, but not tissue Mph, revealed a six-fold increase in monocytes in metastasizing C tumours compared to normal gut. The non-metastasizing B tumours could be divided into one group containing increased numbers of monocytes, and a second group comparable to control gut. T-cell numbers were increased in all tumour stages by an average 1.4-fold, which disguised the lack of consistent pattern in T-cell subset ratios in the tumour stromal tissue. However, in the tumour epithelium, there was a constant decrease in the Ts + c cell subset and a subsequent alteration in T-cell subset ratio in favour of Th + i cells. With the progression from Dukes' Stage B to C, there was an increase in the proportion of monocytes and T cells which were activated as detected by mAbs to the C3b receptor and IL-2 receptor, respectively. These observations suggest that an immune response is in progress in these colorectal tumours and that it is most active in the metastasizing Dukes' C tumours. Whether this response is elicited by the tumour or other elements, whether it is detrimental to tumour growth, or whether it is actively assisting tumour growth and possibly dissemination, are matters of conjecture.

Antibodies, Monoclonal↗

PubMed1985

Family studies of erythrocyte complement receptor type 1 levels: reduced levels in patients with SLE are acquired, not inherited.

It has been claimed that patients with systemic lupus erythematosus (SLE) have an inherited deficiency of erythrocyte complement receptor type 1 (CR1, with ligand binding specificity for C3b, iC3b and C4b). CR1 functions as the only cofactor for factor I-mediated cleavage of iC3b to C3c and C3dg. The activity of this receptor on red cells may be an important mechanism for handling immune complexes which have bound C3b or iC3b. Radioligand binding studies were performed using a monoclonal antibody to CR1, E11, to enumerate these receptors accurately. The results confirmed that patients with SLE have a reduced number of CR1 molecules per red cell, but showed no reduction in CR1 levels amongst their consanguineous relatives. Study of 13 normal families suggested the presence of heritable factors controlling the numbers of erythrocyte CR1 molecules; in particular there was a correlation between mean parental CR1 numbers and CR1 numbers in their children. However, amongst 17 families of 19 patients with SLE, four families were identified in which genotypically 'high CR1' SLE patients had persistently low phenotypes. This is not compatible with the hypothesis that the reduction in erythrocyte CR1 numbers in these patients is inherited.

Antibodies, Monoclonal↗

PubMed1984

Identification of an anti-monocyte monoclonal antibody that is specific for membrane complement receptor type one (CR1).

A monoclonal antibody (E11) was produced by immunization of mice with intact human cells of monocyte lineage. Despite the finding that E11 did not inhibit rosettes with C3b-coated sheep erythrocytes (EC3b), several lines of evidence indicated that E11 was specific for complement receptor type one (CR1). All monocytes, neutrophils, lymphocytes and erythrocytes that reacted with E11 formed EC3b rosettes. The E11 antigen on these cells was shown to be a molecule of 222 +/- 10 kDa. Treatment of lymphocytes, monocytes, and neutrophils with E11 followed by fluorescein-coupled F(ab')2 anti-mouse-IgG at 37 degrees C in buffer lacking sodium azide, led to capping or apparent endocytosis of the E11 antigen and a diminution in CR1 activity of 88%, 59% and 25%, respectively. This same treatment had no detectable effect on monocyte or neutrophil CR3 activity (EC3bi rosettes). Furthermore, with E11-capped lymphocytes, the residual EC3b rosetting was capped directly over the E11-fluorescence cap, whereas EC3d,g rosetting (CR2 specific) was undiminished and distributed evenly around the circumference of cells containing E11-fluorescence caps. Finally, the binding of E11 to cells was inhibited by the prior treatment of these cells with a well characterized rabbit polyclonal anti-CR1. These data indicated that E11 was specific for a site in CR1 that was distal from the C3b-binding site, so that E11 was unable to block CR1 activity. E11 proved to be useful for identifying CR1 on various cells in tissue sections, and for quantitating CR1 on erythrocytes and neutrophils. Erythrocytes and neutrophils from normal individuals were found to bind an average of 610 and 4.6 X 10(4) 125I-labeled E11 molecules per cell. When E11 was visualized in tissues by immunoperoxidase staining, the cells that apparently contained the greatest amounts of CR1 were dendritic reticulum cells and kidney podocytes. The E11 reactive dentritic reticulum cells were characteristic of both follicular and diffuse follicular center cell tumors. Lymphocytes from patients with chronic lymphocytic leukemia (CLL) characteristically expressed little E11, confirming earlier studies that CLL cells lacked CR1 activity detected by EAC1-3b rosette formation. Because normal B cells have been shown to express CR1 at a very early stage of maturation, the absence of CR1 on CLL cells is discordant with the immature nature of CLL cells defined by immunoglobulin expression.

Animals↗

PubMed1984

Electrophoretic and cytochemical characterization of alpha-naphthyl acetate esterases in acute myeloid leukemia: relationships with membrane receptor and monocyte-specific antigen expression.

Alpha-naphthyl acetate esterases (ANAE) were examined by cytochemical and isoelectric focusing (IEF) techniques in 48 cases of acute myeloid leukemia that were classified by conventional morphological criteria. Four main types of ANAE isoenzyme patterns were found by IEF, and comparisons with the expression of membrane receptors (Fc-IgG and C3b) and monocyte-specific antigens (UCHM1, UCHALF, and E11) suggest relationships between ANAE isoenzyme synthesis and distinct myeloid maturational stages. The results further indicate that the blast cells of acute myelomonocytic leukemia (AMML) may represent an immature variant of monocytic leukemia (AMoL) and that morphological examination alone is inadequate in the assessment of monocytic differentiation in acute myeloid leukemias. Inhibition studies of cytochemical ANAE activity with sodium fluoride (NaF) show that the presence of NaF-sensitive or NaF-resistant ANAE enzymes is often unrelated to the diagnostic category of acute leukemia. The results of this study are examined in relation to current concepts of myeloid differentiation, and the application of these findings to the subclassification of acute myeloid leukemias is discussed.

Antibodies, Monoclonal↗

PubMed1984

Monoclonal antibodies specific for platelet glycoproteins react with human monocytes.

Three monoclonal antibodies, P256 , P140, and P112 , react with the 135,000 mol wt IIb component of the glycoprotein IIb/IIa complex. They also react with a 200,000-mol wt protein present at low levels in the complex. Using immunofluorescence techniques, monoclonal antibodies P140 and P112 , but not P256 , can be shown to bind to 80% of human monocytes. However, P256 was able to immunoprecipitate the IIb/IIIa complex from detergent-solubilized monocytes, suggesting that the P256 epitope is less accessible on monocytes than on platelets. The monoclonal antibodies also precipitated molecules of approximately 200,000 mol wt from the monocytes. Two other monoclonal antibodies, J15 (specific for the IIb/IIIa complex) and AN51 (which reacts with the second major platelet glycoprotein complex, I), also react with monocytes. Binding of the monoclonal antibodies to the histiocytic cell line, U937, and promyelocytic cell line, HL-60, reflected the pattern of reaction with monocytes. The presence on monocytes of these glycoproteins, instrumental to the role of platelets in clotting, raises the possibility that monocytes might have similar functions in particular circumstances.

Animals↗

PubMed1984

Monoclonal antibodies differentiating between monocytic and nonmonocytic variants of AML.

Blast cells from 70 cases of acute myeloid leukemia (AML), with a preponderance of monocytic variants (M4 and M5), were stained with a panel of 10 monoclonal antibodies (MoAb) that react with normal myeloid cells. Two McAb, UCHMI and UCHALF, stained cells from nearly every case of M4 and M5 leukemia, but not cells from cases of M1/M2 leukemia. Two other antibodies, E11 and UC45, were also specific for the monocytic leukemias, but stained cells from a lesser proportion of cases. The antibodies TG1, OKM1, Smø, DA2, 28, and 5.5 stained a differing proportion of cases in both the M1/M2 and M4/M5 subtypes. Routine morphology and alpha-naphthyl acetate esterase (ANAE) staining were largely in agreement with the antibody findings, though the interpretation of the fluoride sensitivity of ANAE was apparently misleading in 10% of cases. It is concluded that these antibodies, particularly UCHMI and UCHALF, will be of considerable value in the more precise subtyping of AML and that some of this panel of antibodies will be valuable tools for the investigation of normal monocytic differentiation.

Antibodies, Monoclonal↗

PubMed1984

Monoclonal antibodies specific for human monocytes, granulocytes and endothelium.

Four monoclonal antibodies against antigens of human myeloid cells have been produced and thoroughly characterized in terms of their reactions with peripheral blood cells, cell lines, nine lymphoid and non-lymphoid tissues and the polypeptides with which they react. UCHM1 and SmO identify antigens present on the majority of blood monocytes and a variable, but lower, proportion of tissue macrophages. From their morphology and location in tissues, these cells appear to be recirculating monocytes. SMO antigen is also present on platelets. In addition, both antibodies stained endothelial cells, SMO in all tissues examined and UCHM1 variably. Biochemical investigation indicated that the UCHM1 antigen is a protein of 52,000 MW while the SMO antigen could not be indentified. The antibodies TG1 and 28 identify antigens mainly present on granulocytes. While mAb 28 reacted with neutrophils, TG1 also stained eosinophils and stained strongly a proportion of monocytes. TG1 also reacted variably with some non-haemopoietic cell lines. Both antibodies reacted predominantly with granulocytes in tissue sections. MAb TG1 precipitated a single polypeptide of 156,000 MW from monocytes and granulocytes, while mAb 28 precipitated non-convalently associated polypeptides of 83,000 and 155,000 MW from granulocytes but only a single molecule from monocytes, corresponding to the lower MW chain of 83,000. The epitope with which mAb 28 reacts appears not to be exposed on the surface of intact monocytes. This suggests that a similar or identical 83,000 MW molecule is made by both neutrophils and monocytes, but that its expression differs according to cell type.

Antibodies, Monoclonal↗

PubMed1983

Human monocytes are associated with the formation of fibrin.

Purified populations of human monocytes (greater than 99% monocytic) contain a subpopulation of cells (8-20%) that will surround themselves with a radial array of needles within 15 s after exposure to plasma. The needles are composed of fibrin as demonstrated by gel electrophoresis of isolated needles and by their reaction with a monoclonal antibody, UC45, that is specific for the alpha chain of fibrin. The addition of UC45 antibody to plasma inhibits the formation of the fibrin needles by monocytes, suggesting that the recognized antigen is important for polymerization. In contrast, UC45 binds weakly to conventional plasma fibrin and does not prevent clotting of plasma although the process is prolonged. Thus, the UC45 antigen is more prominently represented or more accessible on monocyte fibrin. At least 1% of the monocytes were able to form fibers at the earliest time that they could be tested. A greater proportion developed this ability between 2 and 6 h in culture. Macrophages from lung, thymus, and breast milk, when incubated for similar periods of time, do not form fibrin needles. However, phagocytes from tonsils were extremely active in this respect. It is speculated that monocytes may be induced to express fibrin as part of their activities in inflammatory lesions.

Animals↗

PubMed1983

Cross-reactivities of monoclonal antibodies between select leech neuronal and epithelial tissues.

Three monoclonal antibodies, originally studied because of their neuron-specific staining in the leech central nervous system, are characterized further here, both immunocytochemically and biochemically, with Western blot staining using the central nervous system and peripheral tissues. The three antibodies react both with neurons and select epithelial tissue in the central nervous system, gut, and penis. Antibody Lan3-8 reacts with neurons in the nerve cord and gut but with epithelial cells in the penis; it binds to a 65K molecule in all three tissues. Lan3-2 and Laz2-369 are considered as a related pair because in the central nervous system the former stains all (four) and the latter generally only half (two) of the neurons in a standard midbody ganglion responding to nociceptive stimulation. In the gut, both antibodies label patches of epithelial cells and Laz2-369 stains a previously unknown type of gut neuron. While a given antibody stains different bands in gut and central nervous system immunoblots, comparing the bands of both antibodies for the same tissue extract makes it apparent that there are similarities in the molecular species that both antibodies recognize. For each monoclonal antibody, the histologically identified tissue antigens need to be correlated with proteins identified on Western blots. Of particular interest are the broad 130K bands to which Lan3-2 and Laz2-369 bind. The question is raised whether the molecular species in these bands represent a family of proteins that serve a specific nociceptive cell function.

Animals↗

PubMed1983

The nature of hairy cells - a study with a panel of monoclonal antibodies.

In all 11 patients with hairy-cell leukaemia (HCL) tested, a high percentage of peripheral blood and splenic (3 cases) hairy cells (HCs) reacted with 2 B-cell-specific monoclonal antibodies (FMC1 and FMC7), but failed to stain with 5 monocyte/macrophage-specific (FMC17, UCHM1, SM1, SMø and OKM1) and with 4 T-cell-specific antibodies (UCHT1, Leu1, 2a and 3a). The data provide further evidence in support of the B-cell nature of the HCs of HCL.

Animals↗

PubMed1983

Human monocytes have prothrombin cleaving activity.

A proportion of human monocytes form long needles of fibrin on their surfaces when they are briefly exposed to human plasma. A number of coagulation factor deficient plasmas (II, V, VII, VIII, von Willebrand, IX, X, XI and XII) were tested for their ability to promote formation of this fibrin. Monocytes failed to make fibrin only in Factor II or prothrombin deficient plasma. Thrombin is involved in the manufacture of monocyte fibrin as shown by the ability of the thrombin specific inhibitor, hirudin, to block the process and by the demonstration that monocytes are able to cleave prothrombin to thrombin, an activity which increases with time of monocyte incubation at 37 degrees C. These results indicate that human monocytes possess a prothrombin cleaving activity although it remains unclear how this activity is generated. It is speculated that thrombin serves a necessary role in both wound healing and tissue repair.

Blood Coagulation↗