摘要:

AbstractLarge numbers of antibody‐forming cells (AFC) can be identified with the Jerne plaque assay in immunized lung lobes of the beagle dog after localized instillation of particulate antigen. Published data suggest that these AFC are secreting antibody and are responsible for increased levels of specific antibody in immunized lung lobes. If AFC in the lung are actively secreting antibody, there should be an increase in the number of mature plasma cells in lung lobes exposed to antigen. The purposes of this study were to evaluate the number of lymphoid cells present in immunized and control lung lobes and to determine if lung immunization produces a localized increase in the number of plasma cells. Sheep red blood cells (SRBC), autologous dog red blood cells, and saline were instilled into specific lung lobes of beagle dogs with the aid of a fiberoptic bronchoscope. Light and transmission electron microscopy studies of tissues from lung lobes instilled with SRBC showed perivascular infiltrates and intra‐alveolar accumulations of lymphoid cells which were not present in control lung lobes. The morphology of these lymphoid cells ranged from small lymphocytes through mature plasma cells. From 5% to 15% of the cells present in the interstitial tissues and alveoli of immunized lung lobes were plasma cells. These observations suggest that lymphoid cells which entered the SRBC immunized lung can mature to plasma cells which are probably responsible for the local production of antigen‐specific antibody.

ISSN:0741-5400    

DOI:10.1002/jlb.41.1.1

出版商:Wiley    

年代:1987

数据来源: WILEY

摘要:

AbstractWe have previously reported that human neutrophils can be permeabilized with the cholesterol‐complexing agent digitonin. These permeabilized cells can be induced to secrete lysosomal constituents when exposed to micromolar levels of free Ca2+, a process that is enhanced by certain guanine nucleotides. We examined the kinetics in this system by employing both direct and indirect measures of secretion. A continuous, fluorescent assay of elastase permits real‐time monitoring of secretion from azurophil granules. The kinetics of elastase release proved to be rapid, beginning within 3‐10 sec and reaching a maximum at 1‐2 min. Changes in the Ca2+concentration did not affect the “lag period” for release. A comparison of the Ca2+dose‐response curves for release of the various granule constituents indicated that elastase was being secreted along with other contents of the azurophil granules. Changes in right angle light scatter (RLS), which have been shown to correlate closely with secretion, also commenced rapidly after the addition of Ca2+; when measured simultaneously, both the Ca2* dose‐response characteristics for changes in RLS and elastase release were very similar. Changes in RLS could be halted within 5 sec by excess EGTA and restarted promptly by repletion with secretory concentrations of Ca2+. In addition, neomycin, a phospholipase C inhibitor, profoundly diminished degranulation as monitored by RLS and end‐point techniques. A continuous assay employing 9‐aminoacridine self‐quenching as a measure of secretion proved far less satisfactory, but, nonetheless, produced similar kinetics and dose‐response characteristics. These data thus suggest that secretion of granule constituents from permeabilized neutrophils takes place rapidly and that the kinetics are comparable to those observed with intact cells.

ISSN:0741-5400    

DOI:10.1002/jlb.41.1.8

出版商:Wiley    

年代:1987

数据来源: WILEY

摘要:

AbstractMonocytes must accumulate in areas of tissue injury and inflammation to effect phagocytosis, antigen presentation, and monokine production. Fibrinogen/fibronectin matrices have been demonstrated in healing wounds and in delayed‐type hypersensitivity skin reactions. We have developed an in vitro system for investigation of the ability of fibrinogen and fibronectin matrices to serve as substrata for human peripheral blood monocyte adherence. Monocyte adherence was greatest on matrices of both fibrinogen and fibronectin, less to fibrinogen alone, and least to fibronectin alone. Lymphokines increased adherence of monocytes to all three surfaces but not to albumin‐coated surfaces.Addition of platelets also caused a dose‐dependent increase in monocyte adherence to all three surfaces. This increased adherence was not a simple function of arachidonic acid metabolites, stable platelet products, nor monocyte binding sites on the platelet membrane. The effect of platelets was not additive to the effect of lymphokines.We conclude that fibrinogen and fibronectin provide a framework for monocyte adherence and that factors present in areas of inflammation and wound healing, such as lymphokines and platelets, can augment this adherence. Such adherence facilitates the transformation of monocytes into macrophages in vitro and may also foster such transformation in vivo.

ISSN:0741-5400    

DOI:10.1002/jlb.41.1.14

出版商:Wiley    

年代:1987

数据来源: WILEY

摘要:

AbstractActivation of the Na+/H+antiport mechanism was studied in human neutrophils by monitoring intracellular pH with a carboxyfluorescein derivative. N‐formyl‐methionylleucyl‐phenylalanine (FMLP) and phospholipase C (PLC) induced biphasic pH changes. Amiloride, which inhibits the antiport, completely blocked alkalinization but enhanced acidification. Polymyxin B, which inhibits protein kinase C, only blocked alkalinization. Activation with phorbol 12‐myristate 13‐acetate (PMA) led to alkalinization only; this was inhibited by amiloride or polymyxin B. Thus, during polymorphonuclear leukocyte (PMN) activation, Intracellular alkalinization appears to be mediated by an amiloride‐sensitive Na+/H+antiport. Antiport activity can also be blocked indirectly by inhibition of protein kinase C activity. Early intracellular acidification does not appear to require kinase activity but is observed when phospholipids are remodeled with PLC. The antiport was also activatable by hypertonic buffered media. This response did not appear to be mediated by protein kinase C because it was unaffected by polymyxin B. Finally, superoxide generation was investigated. It is affected by, but not soley controlled by, either antiport or protein kinase C activity.

ISSN:0741-5400    

DOI:10.1002/jlb.41.1.25

出版商:Wiley    

年代:1987

数据来源: WILEY

摘要:

AbstractA cell resistant to concentrations of mitomycin‐C associated with the inactivation of many in vitro immune responses is described. This cell is responsive to concanavalin A (Con A), poorly adherent to nylon wool, present in relatively greater numbers in lymph node than other lymphoid tissues, and is relatively radiosensitive. In part, the resistance of this T cell appears to relate to a reduced activity of a microsomal reductase responsible for converting mitomycin‐C to its more active form. Discrepancies in reductase activity may represent a way to differentiate among subsets of lymphocytes.

ISSN:0741-5400    

DOI:10.1002/jlb.41.1.33

出版商:Wiley    

年代:1987

数据来源: WILEY

摘要:

AbstractRecent studies suggest that DNA modification, such as methylation of specific bases or substitution of altered bases, can play an important role in the control of eukaryotic gene expression. We chose to examine the effects of two DNA modifying agents, 5‐azacytidine (AZA) and 5‐bromodeoxyuridine (BUdR), on interleukin‐1 (IL‐1) gene expression in the human monocyte cell lines THP‐1 and U937.1. THP‐1 produced IL‐1 upon stimulation with lipopolysaccharide (LPS), whereas U937.1 did not. Following treatment with AZA, U937.1 cells could be induced to produce IL‐1 β mRNA and release IL‐1, but only if a stimulus such as LPS was present. In addition, the level of IL‐1 β mRNA produced and IL‐1 released by THP‐1 cells after induction could be doubled by treatment with AZA. In contrast, we were unable to alter IL‐1 production by treatment of cells with BUdR in the absence or presence of inducers. These results suggest that the production of IL‐1 may be, in part, regulated by methylation of DNA.

ISSN:0741-5400    

DOI:10.1002/jlb.41.1.40

出版商:Wiley    

年代:1987

数据来源: WILEY

摘要:

AbstractThe ability of prostaglandins, glucocorticoids and lipopolysaccharide to modulate I‐A expression on macrophages that continuously or transiently express I‐A was compared. We found that neither prostaglandins nor glucocorticoids affected I‐A expression by macrophages that continuously expressed I‐A. In contrast, prostaglandin E2(PGE2) inhibited the lymphokine‐induced maintenance of I‐A on macrophages that transiently expressed I‐A while glucocorticoids inhibited both the induction and expression of I‐A. Lipopolysaccharide caused a loss in the expression of Class II molecules on macrophages that continuously expressed l‐A by a prostaglandin‐independent mechanism. The lack of effect of PGE2and glucocorticoids may be related to our observation that continuous expression of I‐A does not require its continued synthesis.

ISSN:0741-5400    

DOI:10.1002/jlb.41.1.47

出版商:Wiley    

年代:1987

数据来源: WILEY

摘要:

AbstractAnalysis of macromolecular fraction of platelet release products (PRPr) was undertaken after we observed that pretreatment of human neutrophils with macromolecules (>105daltons) involved in PRPr enhanced phagocytosis of IgG‐sensitized sheep red blood cells (IgG‐SRBC). Sephadex G‐200 gel filtration of PRPr revealed two macromolecular activators and two suppressors of neutrophilic phagocytosis of IgG‐SRBC: MAPP(s), macromolecular activator(s) of phagocytosis from platelets; MSPP(s) macromolecular suppressor(s) of phagocytosis from platelets. The estimated molecular weights of the respective MAPPs were 100 kdaltons to 140 kdaltons (kd) (s‐MAPP) and 200 kd to 290 kd (I‐MAPP) and those of the respective MSPPs were 60 kd to 100 kd (s‐MSPP) and 400 kd to 500 kd (I‐MSPP). It is suggested that an l‐MAPP molecule has at least an s‐MAPP molecule as a functional unit and that MAPPs and larger MSPP (I‐MSPP) might be glycoproteins, while smaller MSPP (s‐MSPP) seems to contain neither carbohydrates nor lipids. As far as the effects of serum and plasma on phagocytosis of IgG‐SRBC by neutrophils are concerned, the serum gave twice as much phagocytic activity as the plasma. Substantial MAPP‐like activities were observed In the serum and MSPP‐like activities were observed in both the serum and plasma.

ISSN:0741-5400    

DOI:10.1002/jlb.41.1.55

出版商:Wiley    

年代:1987

数据来源: WILEY

摘要:

AbstractThe formylpeptide receptors from 40 × 109cells of rabbit peritoneal neutrophils have been solubilized with digitonin and partially purified by sequential fMet‐Leu‐Phe‐Sepharose affinity and wheat‐germ agglutinin agarose affinity chromatography. The binding activity of the receptor toward [3H]fNle‐Leu‐Phe is difficult to restore fully after elution of the receptor from the fMet‐Leu‐Phe‐Sepharose affinity column. A 2,000‐fold purification of the receptor from the particulate fraction is achieved with a yield of about 23%. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis and Coomasie blue or silver staining of purified receptor preparations reveal a major polypeptide with an apparent Mr (50,000‐70,000) and isoelectric points (pi 6.0 ‐ 6.5) that coincides with the polypeptide labeled by the specific affinity cross‐linking probe for formylpeptide receptor (125I‐hexapeptide). The receptor has an apparent Stokes radius of 47 å when analyzed by gel filtration chromatography. Using synthetic peptides poly(Glu‐Tyr) (4:1) as the substrates, a membrane‐associated tyrosine protein kinase activity is detected and can be solubilized by digitonin. Subsequent analysis indicates that the tyrosine kinase activity is not derived from the receptor.

ISSN:0741-5400    

DOI:10.1002/jlb.41.1.63

出版商:Wiley    

年代:1987

数据来源: WILEY

摘要:

AbstractUsing unstimulated rat peritoneal cells as immunogen a new monoclonal antibody KiM4R was produced. Ki‐M4R recognizes follicular dendritic cells (dendritic reticulum cells) in germinal centers of lymphoid follicles in lymphatic tissue. In addition, sinus lining cells, endothelia of postcapillary venules, as well as mesangial cells of the renal glomerula immunoreact with Ki‐M4R in vitro as well as in vivo. This antibody might be useful for studying the interaction of follicular dendritic cells and B‐cell immune response.

ISSN:0741-5400    

DOI:10.1002/jlb.41.1.70

出版商:Wiley    

年代:1987

数据来源: WILEY