摘要:

AbstractFour monoclonal antibodies (mAbs), UC‐A4, UC‐D3, UC‐H9, and IL‐A21, specific for bovine major histocompatibility complex class II proteins are described. Sequential immunoprecipitation experiments using biotin‐labeled peripheral blood mononuclear cells suggested, but did not conclusively establish, that each of these antibodies recognized a different epitope. The epitope identified by IL‐A21 appeared to be common to all of the class II proteins precipitated by the four mAbs, and UG‐D3 and UC‐H9 each appeared to react with distinct epitopes on separate subsets of these class II proteins. Monoclonal antibody UC‐A4 appeared to identify an epitope on a subset of the class II molecules identified by UC‐H9. Differences found in the expression by lymphoid cells of class II proteins identified by the four mAbs were indicative of each mAb recognizing a different epitope. UC‐H9 and IL‐A21 class II proteins were detected on all surface immunoglobulin (S'lg) positive cells in peripheral blood, but UC‐A4 and UC‐D3 class II proteins were not. Expression of UC‐A4 class II proteins, detected at low density on a strikingly reduced number of S'lg+cells from the blood of some bovine leukosis virus‐infected cattle, could be increased by culturing these B cells with lipopolysaccharide. All peripheral blood monocytes expressed UG‐H9 and IL‐A21 class II proteins, but only a proportion of monocytes expressed detectable UC‐A4 and UG‐D3 class II proteins. Almost all mitogen‐stimulated BoCD4+and BoCD8+T cells expressed UC‐H9 and IL‐ A21 class II proteins, whereas fewer stimulated T cells of both subsets expressed UC‐A4 and UC‐D3 class II proteins. All gamma/delta receptor(γ/δR) T cells expressed UC‐D3, UG‐H9, and IL‐A21 class II proteins, but no cells (of γ/δ R+or CD4+/CD2+phenotype) from γ/δ R+T cell‐enriched cultures expressed UC‐A4 class II proteins.

ISSN:0741-5400    

DOI:10.1002/jlb.53.5.479

出版商:Wiley    

年代:1993

数据来源: WILEY

摘要:

AbstractPolymorphonuclear leukocyte (PMN) sequestration within the pulmonary microvasculature is known to occur in association with ischemia/reoxygenation (I/R). This sequestration is dependent on eicosanoids and reactive oxygen species. PMN sequestration within the lungs suggests that pulmonary microvascular endothelial cells (MECs) may in part regulate the I/R response. Simulating I/R, we examined the effect of hypoxia/reoxy‐ genation (H/R) on pulmonary MECs in vitro, with and without PMNs. Significant cellular injury, assessed by51Cr release, occurred upon reoxygenation of MECs (P<.01). Addition of PMNs to the H/R‐injured monolayers did not increase MEC injury. Reoxygenation of MECs also resulted in increased thromboxane (Tx) B2 production compared to controls (P<.01). Inhibition of Tx secretion by aspirin reduced H/R‐induced PMN adhesion to MECs (P<.01). Furthermore, H/R‐induced increases in PMN‐MEC adhesion were prevented by al‐ lopurinol and superoxide dismutase (P<.01). These data suggest that the pulmonary response to H/R is mediated by MEC generation of reactive oxygen radical species and Tx, which promotes increased PMN adhesion.

ISSN:0741-5400    

DOI:10.1002/jlb.53.5.490

出版商:Wiley    

年代:1993

数据来源: WILEY

摘要:

AbstractNitric oxide synthase (NOS) inhibitors have been shown to modulate neutrophil migration. We hypothesized that the NOS inhibitorsNG‐monomethyl‐L‐ arginine (L‐NMMA),NG‐nitro‐L‐arginine methyl ester (L‐NAME), and L‐canavanine (L‐CAN) also modulate human peripheral blood monocyte chemotaxis. To test this hypothesis, monocyte chemotaxis toward formylmethionyl‐ leucyl‐phenylalanine (fMLP) was assessed using a modified blindwell chemotaxis chamber technique. L‐ NMMA and L‐NAME, but not D‐NMMA or L‐CAN, significantly attenuated fMLP‐induced monocyte chemotaxis (P<.05). L‐Arginine and sodium nitroprusside, but not D‐arginine, reversed NOS inhibitor‐induced responses. Dibutryl cyclic guanyl monophosphate (cGMP) attenuated the inhibitory effects of L‐NMMA on monocyte chemotaxis (P<.05). Finally, fMLP increased cGMP generation by monocytes, which was significantly attenuated by L‐NMMA (P<.05). These data indicate that the L‐arginine/NO biosynthetic pathway regulates human monocyte chemotaxis in vitro.

ISSN:0741-5400    

DOI:10.1002/jlb.53.5.498

出版商:Wiley    

年代:1993

数据来源: WILEY

摘要:

AbstractIn a previous study we demonstrated that an increase of monocytes and dendritic cells (MDC) was found in the bronchoalveolar lavage fluid (BAL) after intratracheal instillation of a bacillus Calmette‐Guérin suspension. In the current study, the bright autofluorescence of alveolar macrophages (AMs) was used to separate them efficiently from the MDC. Sorting of freshly isolated BAL cells resulted in a high‐autofluorescent fraction, consisting predominantly of AMs, and a low‐autofluorescent fraction containing the MDC, lymphocytes, and granulocytes. Thus, a clear separation between suppressive (AM) and stimulating (MDC) activity was obtained as shown in antigen‐specific T cell responses. Flow cytometric parameters, density fractionation, and a series of ED monoclonal antibodies raised against rat macrophage antigens showed that both AMs and MDC were diverse populations. After overnight culture, more than 80% of an MDC population with a density range of 1.065‐1.079 changed to a lower density (<1.056) and morphologically developed into DCs with many processes. Concomitantly, monoclonal antibody EDI expression changed from a granular pattern to a discrete juxtanuclear spot localization.

ISSN:0741-5400    

DOI:10.1002/jlb.53.5.504

出版商:Wiley    

年代:1993

数据来源: WILEY

摘要:

AbstractHepatic ischemia‐reperfusion injury is reported to be modulated by neutrophils (PMNs). The adhesion and emigration of PMNs that precede tissue inflammation and necrosis in other organs are mediated, in part, by the leukocyte adhesion complex CD11/CD18. In this study, the role of PMN adhesion via CD11/CD18 in isolated liver ischemia‐reperfusion injury was examined in rabbits using a blocking monoclonal antibody (mAb 60.3) specific for the GDI 8 receptor. Vinblastine‐ induced neutropenia provided significant protection, confirming participation of neutrophils in the pathogenesis of hepatic injury. Inhibition of PMN adherence with mAb 60.3 did not ameliorate injury, as measured by aminotransferase concentrations or a histologic scoring system for injury severity. Histologic sections were scored for pattern and extent of injury as well as neutrophil association with injury. These results suggest a CD18‐ independent mechanism of neutrophil adhesion in the evolution of isolated hepatic ischemia‐reperfusion injury.

ISSN:0741-5400    

DOI:10.1002/jlb.53.5.511

出版商:Wiley    

年代:1993

数据来源: WILEY

摘要:

AbstractThe functional characteristics of neutrophils are exceedingly sensitive to physiological conditions as well as the details of isolation. Exposure to lipopolysaccharide (LPS) or even contamination of the isolating media with traces of LPS is known to play an important role in regulating cell function and expression of receptors. Because of the suspected role of GD14 as a receptor for LPS, we used anti‐CD14 monoclonal antibodies both to identify CD14 in the cell surface of polymorphonuclear leukocytes and to inhibit functional changes elicited by LPS. Cytometric techniques were used to investigate the regulation of CD14 and CR3 on the neutrophil cell surface in whole blood to minimize any effects of isolation. In whole blood neutrophils express low levels of formyl peptide receptor, CD14, and CR3, which increase substantially in response to formyl peptide and LPS. The increases in CR3 and CD14 occurred in parallel and were independent of protein synthesis and tumor necrosis factor (TNF) production. The increase in CR3 was inhibited by antibodies MY4, 3C10, and 28C5 against CD14. These findings are consistent with the notion that in blood the observed receptor up‐regulation is in direct response to the action of LPS on neutrophils through CD14 and does not require products from macrophages such as TNF or the production of C5a from the plasma.

ISSN:0741-5400    

DOI:10.1002/jlb.53.5.518

出版商:Wiley    

年代:1993

数据来源: WILEY

摘要:

AbstractTemporally distinct groups of cytokine expression were observed by reverse transcription‐polymerase chain reaction assay, in situ hybridization, and immuno‐ histochemistry in the livers ofListeria monocytogenes‐infected mice. One group consisted of interferon‐7 (IFN‐ γ), tumor necrosis factor a (TNF‐α), and interleukin‐10 (IL‐10), for which mRNAs were induced within 1 day after challenge. A second group consisted of IL‐2 and IL‐4, for which mRNA was strongly expressed at 1 day but then suppressed at 3 days into the infection. Granulocyte‐ macrophage colony‐stimulating factor (GM‐CSF), IL‐la, and IL‐6 mRNA constituted a third group, which was increased at 3 days after challenge. Distributions of cytokine mRNA‐expressing cells in the liver was observed by in situ hybridization. Cells expressing TNF‐α and IL‐lα mRNA were present throughout liver granulomas, whereas cells that expressed IFN‐γ mRNA were observed mostly along the periphery of granulomas. Cells expressing IL‐2, IL‐4, IL‐6, IL‐10, and GM‐CSF mRNA were distributed principally in the hepatic sinuses. Cells expressing IL‐10 mRNA increased in number early in the infection whenL. monocytogeneswas multiplying in the liver. We conclude that cytokine mRNA expression during the early phases ofL. monocytogenesinfection in mice is temporally regulated and that IFN‐7, TNF‐α, and IL‐lα are expressed by cells associated with hepatic granulomas.

ISSN:0741-5400    

DOI:10.1002/jlb.53.5.525

出版商:Wiley    

年代:1993

数据来源: WILEY

摘要:

AbstractWe studied granulomatous inflammation in simian AIDS using histologic, immunohistologic, and in situ hybridization techniques. Complete Freund's adjuvant was used to induce granulomas in two control animals and two macaques infected with simian immunodeficiency virus (SIV) and having low peripheral CD4+T cell counts. Control animals developed large (>2 cm diameter) epithelioid granulomas containing CD68+macrophages (mφs), epithelioidmφsand multinucleated giant cells (MNGCs), CD4+and CD8+T cells, and small perivascular collections of CD20+B cells. Lymphocytes rarely expressed proliferating cell nuclear antigen (Ki‐67), and only rare endothelial cells expressed vascular cell adhesion molecule 1 (VCAM‐1). In contrast, SIV+animals had smaller (<0.5 cm diameter) epithelioid granulomas characterized by numerous large, dense CD8+, CD20+lymphocyte aggregates with prominent local division (Ki‐67+). Despite low blood CD4+T cell numbers, there was a substantial CD4+T cell infiltrate, accompanied by enhanced endothelial VCAM‐1 expression. These granulomas contained no detectable SIV antigen or RNA. Thus, in simian AIDS, experimentally induced granulomatous responses are grossly attenuated, yet associated with increased local endothelial‐leukocyte signaling and lymphocyte division.

ISSN:0741-5400    

DOI:10.1002/jlb.53.5.532

出版商:Wiley    

年代:1993

数据来源: WILEY

摘要:

AbstractSeveral carbohydrate structures on human granulocytes have been discussed as potential ligands for C‐ type lectins (selectins) on endothelial cells. Among them are the lacto‐series type II chain antigens sialyl‐Lewisx(SLex), Lewisx(Lex), and VIM2. We demonstrated in this study that monoclonal antibodies (mAbs) to Lexand to SLex, but not other anticarbohydrate mAbs (VIM2, CDwl7, CD24), can stimulate granulocytes to form homotypic aggregates. This effect was particularly noticeable with three distinct anti‐LexmAbs (3C6, 4D1, 6C7). Much less impressive effects were also seen with nine other anti‐LexmAbs and with the anti‐SLexmAb CSLEX1. Aggregation was shown to be an active process. It is temperature and energy dependent, requires divalent cations, and is selective in terms of mAb specificity. Anti‐ Lex‐induced homoaggregate formation could be inhibited with CDllb mAb JML‐H11 and CD54 (ICAM1) mAb LB‐2 and thus seems to be associated with activation of the β2‐integrin cytoadhesion pathway.

ISSN:0741-5400    

DOI:10.1002/jlb.53.5.541

出版商:Wiley    

年代:1993

数据来源: WILEY

摘要:

AbstractAlthough tumor growth enhances macrophage (mφ) cytotoxic activity by increasing their tumor necrosis factor‐a (TNF‐a) production, increased prostaglandin E2(PGE2) synthesis reduces most immune responses during tumor growth. Macrophages that do not express major histocompatibility complex class II molecules (la−mφ) are the predominant suppressor and cytotoxic population and are more abundant in tumor‐bearing hosts (TBHs). This study determined if TBH la'mφsare the major population producing TNF‐α and PGE2 and if these molecules affect la' mφ‐mediated suppression of alloantigen‐stimulated T cell proliferation. Normal host (NH) and TBH splenic Ia+‐depleted (la−)mφssynthesized more TNF‐a than their respective whole populations (WPs) when cultured with lipopolysaccharide and interferon‐7. TBH la' mφs produced the most TNF‐α. Northern blot analyses showed that la' mφs had higher amounts of TNF‐α mRNA expression than their respective WP, and TBH la” mφs expressed the highest amounts of TNF‐α mRNA. When WP and la' NH and TBH mφs were added to alloantigen‐stimulated T cells, suppression of T cell proliferation mediated by la' mφs was greater than by their respective WP. TBH Ia−mφswere most suppressive. The blockage of PGE2 production reduced suppression mediated by TBH la” mφs more than by all other mφpopulations. A PGE2‐specific enzyme‐linked immunosorbent assay showed that PGE2 production was greater in la' mφ‐ than in WP mφ‐containing cultures and greatest in cultures containing TBH la' mφs. Because TNF‐α enhances T cell responses, its effects on la'mφ PGE2‐mediated suppression was determined. When TNF‐ a was added to mφ‐containing T cell cultures, TNF‐α directly stimulated NH, but not TBH, la' mφs, which enhanced T cell proliferation. However, inhibiting PGE2 production allowed TNF‐a to stimulate T cell proliferation in TBH la” mφ‐containing cultures. Collectively, these data show that la' mφs are the major TNF‐α‐ and PGE2‐producing cells and that these molecules are partly responsible for the tumor‐induced increase in mφ‐ mediated cytotoxicity and suppression, respectively. TNFα not only mediates cytotoxicity but also counteracts la−mφPGE2‐mediated suppression. Although tumor growth increases la' mφTNF‐α production, enhanced PGE2 production blocks TNF‐α's stimulatory action on la”mφs,which favors their suppressor function during tumor growth.

ISSN:0741-5400    

DOI:10.1002/jlb.53.5.550

出版商:Wiley    

年代:1993

数据来源: WILEY