Leukocyte Surface Antigens Research Articles

Changes in antigen densities on leukocyte subsets correlate with progression of HIV disease

In a cross-sectional study of 154 HIV-infected and 33 uninfected healthy adults, we show that characteristic changes in the levels of expression of leukocyte surface antigens occur in the HIV-infected individuals. These changes, which collectively occur on virtually every leukocyte subset, are specific: a particular antigen may increase or decrease on one subset of PBMC but remain constant on another. Furthermore, within any particular subset, the levels of one or more antigens may change, while the levels of other surface antigens on the same cells remain constant. Some of these antigens density changes have been noted before, e.g. increased CD20 on B cells, and increased CD38 and HLA-DR on CD8 T cells. However, the multiparameter flow cytometry methodology used here reveals changes in a substantially larger number of surface markers, some of which are restricted to fine subsets of PBMC, such as naive or memory T cell subsets. For many of these antigens, the change in expression correlates with absolute CD4 counts >500/microl; others differ only in those with counts >100microl. The changes in antigen densities we observed on B and T cells are consistent with the observation of a persistent quasi-activated state of these cells in HIV-infected individuals. Similarly, the altered expression of the signal-transducing molecules CD7 and CD16 that we demonstrated for NK cells may correlate with the functional defects previously demonstrated in NK cells. Thus, measurements of antigen densities such as those demonstrated here may provide surrogate markers for the altered functional capacities of PBMC subsets in HIV-infected individuals, and may thereby provide a much simpler assay for immunocompetence than in vitro functional assays.

In VitroModulation of Function, Proliferation, and Phenotype of Bovine Mononuclear Leukocytes by 13-Cis Retinoic Acid

Abstract 13-cis retinoic acid at 10-9 and 10-8 M enhanced IgM secretion by pokeweed mitogen-stimulated bovine peripheral blood mononuclear leukocytes. Based on these data, effects of 10-8 mol/L of 13-cis retinoic acid on the proliferation and phenotype of bovine peripheral blood mononuclear leukocytes were evaluated. Cells from 2- to 14-d control and treated cultures were counted and their phenotype determined using monoclonal antibodies to bovine leukocyte surface antigens. A time-dependent decrease in cell numbers in resting cultures was unaffected by 13-cis retinoic acid. Cellular composition of resting cultures was also unaffected by 13-cis retinoic acid. In contrast, cell proliferation in 6-, 10- and 14-d poke-weed mitogen-stimulated cultures was suppressed but not abrogated by 13-cis retinoic acid treatment. Percentages of leukocyte subsets in pokeweed mitogen-stimulated cultures was affected negligibly by 13-cis retinoic acid. In contrast, actual numbers of CD2+ and CD4+ T-cells, and interleukin-2 ...

Elevated soluble CD4 levels in the cerebrospinal fluid in patients with adult T-cell leukemia.

Levels of the soluble form of the leukocyte surface antigen CD4 (sCD4) were measured by enzyme linked immunosorbent assay (ELISA) in the cerebrospinal fluid (CSF) of patients with adult T-cell leukemia (ATL) and other malignant and non-malignant diseases. All patients with ATL and meningeal infiltration had markedly elevated levels of sCD4 in the CSF (53.7 +/- 34.9 U/ml). ATL patients without CSF pleocytosis often had elevated levels of sCD4 (15.1 +/- 9.2 U/ml). Non-ATL patients with CSF pleocytosis had elevated levels of sCD4 (23.3 +/- 12.2 U/ml) and those without CSF pleocytosis also showed elevation of sCD4 levels (16.8 +/- 9.3 U/ml). However, the mean levels of sCD4 in CSF from these patients were significantly lower than ATL patients with meningeal infiltration. Soluble CD4 in the CSF from healthy volunteers were below the detectable limit. We conclude that meningeal infiltration of CD4(+) ATL cells is strongly associated with elevated sCD4 levels in CSF, and some part of sCD4 in CSF may be originated from the native cells in the CNS as a response of inflammatory stimulations. Therefore, measurement of sCD4 may be useful in the diagnosis of meningeal infiltration and/or meningeal irritation in patients with ATL.

Reactivities of 20 anti-human monoclonal antibodies with leucocytes from ten different animal species

Twenty commercially available monoclonal antibodies (mAbs) raised against various human leucocyte surface antigens were tested on lymphocytes, monocytes and granulocytes from horse, pig, cow, sheep, goat, dog, mink, rabbit, rhesus monkey as well as man. Eight antibodies reacted with leucocytes from some of the animals. These were the antibodies against CD2, CD4, CD5, CD8, CD14, CD18, HLA-DR, and the HLA-ABC antigen. The CD18 antibody reacted with lymphocytes, monocytes and granulocytes from all animals tested except goat. The CD14 antibody reacted with monocytes from pig, cow, sheep, goat, dog, mink, rabbit and monkey and with granulocytes from pig and rabbit. The anti-HLA-ABC reacted with leucocytes from monkey and cow. Finally, the CD2, CD4, CD5 and CD8 antibodies reacted with leucocytes from monkey only.

Enzyme-linked immunosorbent assay and flow cytometric methods to screen hybridoma culture supernatants for antibodies to bovine neutrophil surface antigens, and monoclonal antibody production and characterization

Summary Enzyme-linked immunosorbent assay and flow cytometric methods to screen hybridoma culture supernatants for antibodies to bovine neutrophils (surrace antigen-specific) were optimized. Sensitivity of the 2 methods was compared. A panel of 14 murine monoclonal antibodies (mab) to surface antigens of bovine polymorphonuclear neutrophilic leukocytes (neutrophils) was produced by hybridoma technology, and their isotypes were determined by wholecell elisa. Monoclonal antibody reactivity with neutrophils, eosinophils, and lymphocytes isolated on phosphate-buffered saline solution and on Ficoll-sodium diatrizoate were compared. Biochemical characterization of antigens recognized by mab was performed by immunoblot analysis. Neutrophil plasma membranes were isolated on sucrose gradients (20, 32, and 50%) and purified for polypeptide characterization. Neutrophil surface proteins were characterized by external labeling with 125I. The flow cytometric method was proven to be more sensitive and rapid than elisa to screen hybridoma supernatants. This method allowed light-scatter gating of live neutrophil populations for analysis, which eliminated nonspecific binding of antibodies to contaminating cells and dead neutrophils. The optimal conditions for flow cytometric analyses were 5 × 105 neutrophils and 1 µg of fluorescein-labeled F(ab′)2/assay as the second antibody. The optimal conditions for hybridoma screening by elisa were neutrophil concentration of 2.5 × 105/well, using a 96-well polystyrene microtitration plate as solid support, and 2,2′-azino-di[3-ethyl-benzthiazoline sulfonate (6)] with H2O2 as the chromogenic substrate. Tissue culture plates as solid support and 3,3′, 5,5′- tetramethyl benzidine, with H2O2 as the chromogenic substrate, were equally as sensitive. Panel mab reacted differently with neutrophils, eosinophils, and lymphocytes. Isolation of these cells from blood on Ficoll-sodium diatrizoate generally did not alter mab reactivity. Coomassie blue-stained gels of neutrophil plasma membrane proteins contained about 25 polypeptide bands, 13 of which were major bands. Autoradiography revealed about 11 surface proteins, 5 of which were heavily labeled with Monoclonal antibody S7G8 identified a 65-kd protein and mab S8G10 identified 65- and 70-kd proteins. On the basis of molecular weight, mab S7G8 and S8G10 are comparable to human CD15, CDl6, and CD64 molecules. The mab generated in this study are potential candidates to discern bovine neutrophil function and heterogeneity.

In vitro modulation of proliferation and phenotype of resting and mitogen-stimulated bovine mononuclear leukocytes by 1,25-dihydroxyvitamin D 3

Effects of 1,25-dihydroxyvitamin D 3 [1,25(OH) 2D 3] on the proliferation and phenotype of normal bovine peripheral blood mononuclear leukocytes (MNL) were studied in vitro. Resting and pokeweed mitogen (PWM)-stimulated MNL cultures were supplemented with 1.0 nM of 1,25(OH) 2D 3 at the beginning of the culture period. Leukocytes were removed from 2-, 4-, 6-, 8-, 10-, 12-, and 14-day unsupplemented and 1.25(OH) 2D 3-supplemented cultures, and were counted and phenotyped using monoclonal antibodies to bovine leukocyte surface antigens. Cell numbers in resting MNL cultures decreased with time and were unaffected by 1.25(OH) 2D 3 supplementation. The progressive increase in cell numbers in PWM-stimulated MNL cultures was suppressed, but not abolished by 1,25(OH) 2D 3. Suppression was greatest in PWM-stimulated 6- to 12-day cultures. Cellular composition of resting MNL cultures was unaffected by 1,25(OH) 2D 3. Pokeweed mitogen-stimulated cultures supplemented with 1,25(OH) 2D 3 had fewer total T-cells and CD4 + T-cells at 6–14 days. In contrast, numbers of CD8 + T-cells were significantly higher in 1,25(OH) 2D 3-supplemented cultures at 6, 10, and 14 days. Effects of 1,25(OH) 2D 3 on CD4 + and CD8 + T-cell populations were manifested by a significant reduction in the CD4 +:CD8 + T-cell ratios in 6- to 14-day cultures. Proliferation of IL-2 receptor + and MHC class II antigen + cells was also reduced in supplemented 6- to 14-day cultures, indicating events associated with PWM-induced MNL activation were suppressed by 1,25(OH) 2D 3. These findings indicate that 1,25(OH) 2D 3 modulates the proliferation and differentiation of bovine MNL in vitro. Our results also suggest that changes in plasma or tissue 1,25(OH) 2D 3 concentrations that occur during the peripartum period and in clinical cases of milk fever may regulate the bovine immune system in vivo.

A simple flow cytometric procedure for the determination of surface antigens on unfixed leucocytes in whole blood

A novel procedure has been developed for the quantitation by flow cytometry of function-associated antigens on neutrophils and monocytes in unlysed, unfixed, peripheral blood samples. Freshly drawn blood anticoagulated with the serine esterase inhibitor, phenylmethylsulphonyl fluoride, is mixed with the vital nucleic acid stain, LDS-751, labelled with monoclonal antibodies for 5 min at 4°C, dilluted and analysed in a five-parameter flow cytometer. The three major leucocyte subpopulations (neutrophils, lymphocytes and monocytes) can be resolved in real time on the basis of their side light scattering and staining intensity with LDS-751 in the FL3 channel (erythrocytes and platelets stain very weakly), whilst the fluorescence intensity due to bound fluorescein isothiocyanate- or phycoerythrin-labelled antibody is monitored simultaneously in the FL1 or FL2 channels respectively. This procedure avoids potential artefacts that can occur due to the use of fixatives, erythrocyte lysing agents, or anticoagulants which are also divalent metal ion chelators. It should be widely applicable for the quantitation of those function-associated antigens, such as adhesion molecules and immune complex receptors, whose surface expression can be rapidly upregulated following activation, as well as for the quantitation of those leucocyte surface antigens whose expression is not subject to rapid modulation.

The leukocyte surface antigens CD11b and CD18 mediate the oxidative burst activation of human peritoneal macrophages induced by type 1 fimbriated Escherichia coli.

Analysis by immunofluorescence-activated cell sorting of human peritoneal macrophages from patients undergoing intermittent peritoneal dialysis revealed that they express the CD11/CD18 surface antigens, with CD11b and CD18 as the predominant ones. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of immunoprecipitates obtained from lysates of 125I-labeled macrophages with rabbit polyclonal antibodies against the CD11a-c/CD18 complex or against CD18, revealed four radioactive bands corresponding to CD11a, CD11b, CD11c, and CD18. Monoclonal antibodies against CD11b and CD18 inhibited by 80 and 90%, respectively, the oxidative burst activation of the macrophages by type 1 fimbriated Escherichia coli, whereas monoclonal antibodies against CD11a, CD11c, and CD43 were without effect. Our results suggest that CD11b and CD18 (receptors for C3bi) serve also as receptors for mannose-specific E. coli on human peritoneal macrophages and may be involved in the lectinophagocytosis of the bacteria by these cells.

Lectin binding to chronic inflammatory gingival tissue: possible adhesion mechanisms based on lectin-carbohydrate interactions.

In this study, we analyzed the expression of different leukocyte surface antigens, of the adhesion molecules ELAM-1 and GMP-140 and binding of various lectins and neoglycoproteins in inflamed gingival tissue. Cell suspensions from collagenase-digested gingiva were analyzed by flow cytometry in a FACScan. The expression of ELAM-1, GMP-140, carbohydrate structures and lectins in gingival specimens was also studied by immunohistochemistry. Gingival tissue of patients with active periodontal disease contained between 5% and 50% CD45+ mononuclear cells, consisting mainly of CD19+ cells (B lymphocytes). CD62, resembling GMP-140, and ELAM-1 were strongly expressed on endothelial cells of these patients. Control subjects usually contained almost no CD45+ cells in their gingiva and no CD62+ or ELAM-1-positive endothelial cells could be found in 5 of 6 control persons. Analysis of the glycosylation pattern revealed staining of infiltrating cells by peanut agglutinin (PNA; specificity for galactose), whereas soy bean agglutinin (SBA; specificity for N-acetyl-galactosamine) bound to epithelial cells. An endogenous lactosyl-specific lectin could be detected on endothelial cells by binding of lactosyl-BSA. Ulex europeus I agglutinin (UEA-1, specific for fucose) showed selective staining of endothelial and epithelial cells. Expression of a fucose-binding lectin, demonstrated by binding of fucosylated BSA, could be found on infiltrating cells. The adhesion molecules ELAM-1 and GMP-140 seem to be involved in cell adhesion during chronic inflammation of the gingiva. Interaction of other carbohydrate residues with endogenous lectins might resemble additional adhesion mechanisms in inflamed gingiva.

The genes for CD37, CD53, and R2, all members of a novel gene family, are located on different chromosomes.

CD37, CD53, and R2 leukocyte surface antigens are members of a novel family of structurally related proteins. They all have four transmembrane-spanning domains with a single major extracellular loop. The CD37 is expressed on B cells and on a subpopulation of T cells. The CD53 is known as a panleukocyte marker. The R2 protein is an activation antigen of T cells. The CD37, CD53, and R2 genes were assigned with the help of human/rodent somatic cell hybrids and human-specific probes to human chromosomes 19, 1, and 11, respectively. For the regional assignment, various deletion hybrids were used to map CD37 to 19p13-q13.4, CD53 to 1p12-p31, and R2 to 11p12.

Microglia in degenerative neurological disease.

Microglia express many leukocyte surface antigens which are upregulated in such chronic degenerative neurological diseases as Alzheimer's disease (AD) and amyotrophic lateral sclerosis (ALS). These surface antigens include leukocyte common antigen, immunoglobulin Fc receptors, MHC class I and class II glycoproteins, beta 2-integrins, and the vitronectin receptor. Ligands for these receptors are also found. They include immunoglobulins, complement proteins of the classical pathway, T lymphocytes of the cytotoxic/suppressor and helper/inducer classes, and vitronectin. T lymphocytes marginate along capillary venules, with some penetrating into the tissue matrix. Immunoglobulins and complement proteins are synthesized locally in brain, although they may also come from the bloodstream if the blood-brain barrier is compromised. The membrane attack complex, which is formed from C5b-9, the terminal components of complement, has been identified in AD and multiple sclerosis brain tissue. In addition, proteins designed to defend against bystander lysis caused by the membrane attack complex, including protectin, C8 binding protein, clusterin, and vitronectin, are associated with damaged neuronal processes in AD. Autodestruction may play a prominent part in these 2 diseases.

BglII restriction fragment length polymorphism at the gene locus coding for the leukocyte surface antigen CD37.

BglII restriction fragment length polymorphism at the gene locus coding for the leukocyte surface antigen CD37.

Identification of the leukocyte adhesion molecules CD11 and CD18 as receptors for type 1-fimbriated (mannose-specific) Escherichia coli

Attachment of bacteria to phagocytic cells may be mediated by lectin-carbohydrate interactions, resulting in lectinophagocytosis. The best-studied system is the interaction of type 1-fimbriated (mannose-specific) Escherichia coli with human phagocytic cells. Here we demonstrate that the leukocyte integrins CD11 and CD18 (CD11/CD18) constitute the major receptors for type 1-fimbriated E. coli. Bacteria were bound in a dose-dependent and saturable manner to CD11/CD18, which was immobilized to microwells, whereas nonfimbriated E. coli cells failed to bind. The binding was efficiently inhibited (82 to 85%) by methyl-alpha-mannoside but not by galactose, and it was reduced by treatment of the immobilized CD11/CD18 with sodium metaperiodate, endoglycosidase H, or a mixture of endoglycosidase F and N-glycosidase. The fimbriated bacteria also bound to CD11a,b,c and CD18 separated by polyacrylamide gel electrophoresis with sodium dodecyl sulfate and blotted onto nitrocellulose paper. This binding was inhibited specifically by methyl-alpha-mannoside and was significantly diminished by treatment of the blots with sodium metaperiodate. Only minimal binding to the blotted CD11/CD18 that had been deglycosylated enzymatically prior to electrophoresis was observed. On blots of granulocyte lysates, specific binding to two glycoproteins (Mrs, 90,000 to 100,000 and 165,000) with mobilities similar to that of CD11/CD18 was observed. Monoclonal antibodies to CD11a, CD11b, or CD18 inhibited the binding of the bacteria to intact human granulocytes by 55 to 80%, whereas antibodies against other leukocyte surface antigens were not inhibitory. We conclude that type 1-fimbriated E. coli binds to human granulocytes via the oligomannose and hybrid N-linked units of CD11/CD18. Since CD11b/CD18 and CD11c/CD18 are known to serve as receptors for complement fragment iC3b, this study provides a link between opsonophagocytosis and lectinophagocytosis.

Soluble CD4 in patients with rheumatoid arthritis and osteoarthritis

An ELISA was used to measure the soluble form of the leukocyte surface antigen CD4 (sCD4) in the sera and synovial fluids (SF) of patients with rheumatic diseases. Patients with rheumatoid arthritis (RA) had raised levels of sCD4 in both their sera and synovial fluid compared to age-matched healthy controls. In patients with osteoarthritis levels of sCD4 in SF and sera were lower than in RA but higher than in sera of healthy individuals. Mononuclear cells from the synovial fluid of RA patients were found to produce spontaneously high levels of sCD4, but autologous blood cells only produced comparable levels after in vitro stimulation with mitogenic lectin. In individual RA patients with active disease, serial sCD4 levels fell preceding clinical improvement. In three patients where serum sCD4 levels fell and clinical imporvement occurred, subsequent small increases in serum sCD4 preceded increased clinical disease activity by up to 5 days. Synovial fluid levels of sCD4 correlated positively with soluble interleukin 2 receptor levels but no correlation was found with sCD8 levels. We conclude that the release of sCD4 reflects the involvement of T helper cells and macrophages in the pathogenesis of joint inflammation, especially in RA.

A Monoclonal Antibody to Human Leukocyte Common Antigen, SHL-1, and its Use for Formalin-Fixed, Paraffin-Embedded Tissues

The authors describe a newly characterized murine monoclonal antibody to the human leukocyte surface antigen, SHL-1. The antigen belongs to the leukocyte common antigen (LCA) family, and its molecular weight is about 180,000 daltons, which is similar to that of some previously characterized LCAs. The SHL-1 antigen is resistant to conventional tissue-fixation and embedding procedures. This antibody can therefore be used in the immunohistochemical staining of paraffin-embedded tissue sections. Wide screening with a sufficient number of both fresh and routinely processed paraffin-embedded tissues was done with indirect immunoperoxidase technique. With this procedure, SHL-1 labeled the majority of normal leukocytes and hematopoietic malignancies. Some B-cell malignancies were not stained with this antibody. The non-hematologic malignancies posing diagnostic problems of differentiation from lymphomas or leukemias were completely negative to SHL-1. The immunoreactivity to SHL-1 of samples from 24 leukemic patients and 15 human tumor cell lines was determined by the immunofluorescence method. Of 24 leukemic preparations, 23 were strongly reactive to this antibody. One case of B-cell leukemia did not react with SHL-1. No immunoreactivity was demonstrated in non-hematopoietic tumor cell lines. The overall reaction pattern of SHL-1 proved its usefulness in both diagnostic and research practice in hematological disorders. This antibody detected cell surface antigens of the T cell series more effectively than those of the B-cell series in terms of the positive number of cells and mean fluorescence intensity.

Analysis of leukocyte surface antigens on ethanol-fixed paraffin-embedded tissue material

Ethanol-fixed paraffin-embedded specimens of human tissues were studied whether the surface antigens of leukocytes in these tissues can be stained and analyzed. Three-layer indirect immunoperoxidase staining was performed on the ethanol-fixed paraffin-embedded sections by the use of several monoclonal antibodies for whole human leukocytes (Dako LC), B cells (Dako CD-22, 4KB5, and L26; Leu 14), T cells and their subsets (Dako UCHL-1, T1, T3, T4 and T8; Leu 4, 3a and 2a) and monocyte/macrophage lineage (Dako macrophage, Leu M1, M3 and M5). The results were compared with those on fresh-frozen sections. No essential differences were obtained between the paraffin-embedded and the fresh frozen sections stained by the following antibodies: Dako LC for whole human leukocytes; Dako UCHL-1, T3 and Leu 4 for T cells; Dako CD22, 4KB5, L26 and Leu 14 for B cells; Dako macrophage, Leu M1 and M5 for monocyte/macrophage lineage. On the other hand, the subsets of T cells could only be detected on the fresh-frozen sections. The results of the leukocyte analysis on the paraffin-embedded specimens of several renal diseases were very similar to those reported by other investigators on fresh-frozen sections or PLP-fixed materials. Thus, by the use of appropriate monoclonal antibodies, the ethanol-fixed paraffin-embedded material can be used for leukocyte analysis except for the definition of T cell subsets.

Contribution of mononuclear leucocytes to the progression of experimental focal glomerular sclerosis

Uninephrectomized Sprague-Dawley rats repeatedly administered with aminonucleoside of puromycin and protamine sulfate developed progressive focal glomerular sclerosis (FGS). The contribution to disease progression of both glomerular and interstitial infiltrating leucocytes was studied throughout the disease evolution. Leucocyte subsets were quantitated with an immunoperoxidase technique using monoclonal antibodies for rat leucocyte surface antigens: OXI (total leucocytes) OX6 (Ia positive cells), OX8 (suppressor/cytotoxic T cells), OX19 (total T cells), OX22 (B cells and subsets of T cells), and ED1 (macrophages/monocytes). In the glomeruli, macrophages and Ia positive cells were significantly increased when sclerotic lesions appeared, but T lymphocytes and subsets of T lymphocytes were not found. However, in the interstitium, all leucocytes were identified and increased in number throughout the disease evolution. Early in the disease, monocytes and lymphocytes were both present in large numbers, but at the end stage of the process, the predominant infiltrating leucocytes were CD4+ve T cells. In FGS rats treated throughout the disease with oral prednisolone (begun after disease induction), renal function was significantly better than in the untreated group, whereas the sclerosis and leucocyte accumulation in the glomeruli were unchanged. However, prednisolone treatment resulted in significantly fewer interstitial leucocytes and especially reduced the numbers of CD4+vc cells. These results suggest that the glomerular sclerotic lesions are related to the participation of macrophages independent of T cells, and that immune mechanisms mediated by T cells in the interstitium have an important role in the progression of this disease to end-stage renal failure.(ABSTRACT TRUNCATED AT 250 WORDS)

Evidence for membrane differentiation in polarised leucocytes: the distribution of surface antigens analysed with lg–gold labelling

The distribution of a number of leucocyte surface antigens was studied on both round and polarised neutrophil or mononuclear leucocytes using Ig-gold conjugates with transmission electron microscopy. Thin sections of cells, which had been lightly fixed before antibody labelling, were analysed using a statistical method to determine: (1) whether the antigens had a non-random distribution or 'clustering' over the cell surface; and (2) whether there was any overall bias in labelling to give a polarised distribution. Comparison between the results of this analysis and cell morphology were made. The results indicated that with the antigens investigated here, CD45, CD15, HLA-DR and CR3, the majority of polarised cells had a calculated direction of overall asymmetry of gold particles that was aligned with the long axis of morphological polarity. Maximal asymmetry was seen in polarised cells labelled for CD45 and HLA-DR, with labelling ratios of up to 6:1 between the front and back of the cell. A number of round mononuclear cells demonstrated significant polarisation of gold particles but this had no apparent morphological correlation and, in general, round cells showed a low degree of asymmetry. However, there was evidence that both round and polarised cells had a non-random distribution or 'clustering' of gold particles, which was more marked in morphologically polarised cells and particularly significant in polarised neutrophil leucocytes labelled for CR3. The significance of these results for models of cell locomotion involving membrane flow is discussed.

Temporal arteritis: Cell composition and the possible pathogenetic role of cell-mediated immunity

A biopsy specimen exhibiting the typical morphologic characteristics of temporal arteritis was studied by using light, immunofluorescent, and electron microscopy and immunohistochemical techniques. The granulomatous lesion consisted of clusters of macrophages, epithelioid cells, giant cells, and the peripheral lymphocyte mantle, and was localized mainly in the media. Neutrophils were rare, and fibrinoid necrosis was absent. In immunofluorescent and immunohistochemical studies, no significant deposition of immunoglobulins or complement was observed. Immunohistochemical study with monoclonal antibodies to leukocyte surface antigens demonstrated that the central aggregated granulomatous infiltrate consisted of OKTM1 +, Leu-M3 +, HLA-DR + epithelioid macrophages and multinucleated giant cells, whereas OKT8 +, HLA-DR + (suppressor/cytotoxic) T cells predominated in the peripheral lymphocyte mantle. These findings suggest that cell-mediated immunity, especially T cell-regulated granulomatous reaction, may play an important role in the pathogenesis of temporal arteritis. By electron microscopy, smooth muscle cells often exhibited closely attached macrophages, epithelioid cells, and giant cells, and displayed a variety of cell injuries. It therefore seems likely that smooth muscle cells are a primary target of the granulomatous reaction.

Reactivity of eleven anti-human leucocyte monoclonal antibodies with lymphocytes from several domestic animals

Nine commercially available monoclonal antibodies and two monoclonal antibodies from The American Type Culture Collection, raised against various human leucocyte surface antigens, were tested on lymphocytes from cow, sheep, goat, swine, horse, cat, dog, mink, and rabbit as well as man. Four antibodies bound to lymphocytes from some of the animals. These were the antibodies against CD8 and CD4 antigen, the antibody to C3b-receptor, and the antibody to the HLA-DR antigen. The CD8 antigen-reactive antibody reacted with lymphocytes from mink, cat, dog, and sheep, while the CD4 antigen-reactive antibody reacted with lymphocytes from mink. The anti-C3b-R antibody reacted with lymphocytes from horse, swine, dog, and cat, and the anti-HLA-DR reacted with lymphocytes from cow, goat, sheep, horse, dog, cat, and mink.