bluuebunny/crossref_metadata_2025 huggingface dataset:
CD5–Positive and CD5–Negative Rheumatoid Factor–Secreting B Cells in IgA Nephropathy, Rheumatoid Arthritis and Graves’Disease
Authors: JONES B. M. , CHENG I. K. P. , WONG R. W. S. , KUNG A. W. C.
Published: July 2006

The relative contributions of CD5+ and CD5– B–cells in production of rheumatoid factors (RF) was evaluated in polyclonally activated B–cells from patients with IgA nephropathy (IgAN), rheumatoid arthritis (RA) and Graves’ disease (GD). In IgAN and RA, diseases in which RFs are believed to be involved in pathogenesis, there were 10– and 4–fold decreases respectively in CD5+ IgG–RF–secreting B–cells compared with controls. Furthermore, the number of CD5– IgG–RF– and IgA–RF–secreting B–cells were increased 12– and 14–fold in IgAN and 9– and 4–fold in RA. Such abnormalities were not apparent in GD, in which RFs have not been implicated in pathogenesis. These findings are compatible with the concept of CD5+ RF–secreting B–cells normally acting to prevent production of potentially pathogenic RFs by CD5– B–cells. When IgAN or RA patients’ B–cells were activated in the presence of control instead of autologous CD4+ cells, numbers of RF– secreting CD5– B–cells were reduced to the levels seen with control B–cells plus control T–helper cells. Presumably lymphokine secretion profiles of T–helper cells would be important in determining whether CD5+ or CD5– B–cells are activated to secrete RFs, and perhaps therapeutic manipulation of these profiles could restore normal activity of CD5+ B–cells in IgAN and RA.
Gluten Stimulation of Coeliac Mucosa In Vitro Induces Activation (CD25) of Lamina Propria CD4H T cells and Macrophages but no Crypt‐Cell Hyperplasia
Authors: HALSTENSEN T. S. , SCOTT H. , FAUSA O. , BRANDTZAEG P.
Published: July 2006

Jejunal biopsy specimens from 10 patients with treated coeliac disease and seven non‐coeliac controls were challenged in vitro with peptic‐tryptic gluten digest. Mucosal T cells were examined in situ by three‐colour immunofluorescence staining for expression of the activation marker CD25 (the p55 α‐chain of intcrlcukin‐2 receptor) and the nuclear proliferation marker revealed by monoclonal antibody Ki‐67. Intraepithelial T cells expressed CD25 rarely whereas the proportion of activated lamina propria T cells increased (P< 0.002) from median 2.8% (cultured with 20% fetal calf serum alone for 24–48 h) to 10.0% after 24h with gluten (n= 10; range 1.1–17.4%) and to 10.4% after 48 h (n = 7; range 1.4–17.5%). Such gluten‐induced increase of CD25+ T cells was not observed in specimens from non‐coeliac control subjects. Crypt‐cell hyperplasia and T‐cell proliferation (Ki‐67+) were observed neither in the coeliac nor in the control mucosae after gluten stimulation. Three‐colour staining combining a polyclonal antibody reagent to CD3 and a monoclonal antibody to CD25 with a monoclonal antibody to CD45RO, CD4. CDS, the p75 β‐chain of intcrleukin‐2 receptor, integrin χEβ7, or HLA‐DR showed that most of the CD25+ T cells (> 90%) were CD4+ CDS, co‐expressed CD45RO and the p75 β‐chain. and often also the integrin χEβ7 but not HLA–DR. In addition to these activated T cells, a dominating population of CD25+ CD3‐CD4+ subepithelial pan‐HLA–class I+ macrophages (CD68+) with variable expression of the p75 β‐chain was often induced by gluten challenge.
On the Interaction between Protein L and Immunoglobulins of Various Mammalian Species
Authors: DE CHÂTEAU M. , NILSON B. H. K. , ERNTELL M. , MYHRE E. , MAGNUSSON C. G. M. , ÅKERSTRÖM B. , BJÖRCK L.
Published: July 2006

Protein L, a cell wall molecule of certain strains of the anaerobic bacterial species Peptostreptococcus magnus, shows high affinity for human immunoglobulin (Ig) light chains. In the present study protein L was tested against a panel of human myeloma proteins of the IgG, IgM, IgA and IgE classes, and strong binding was seen with antibodies carrying kappa light chains. A high degree of specificity for Ig was demonstrated in binding experiments with human plasma proteins. Apart from human Ig, strong protein L‐binding activity was also detected in the serum of 12 out of 23 tested additional mammalian species, including other primates and rodents. Subsequent analysis with purified Ig samples demonstrated the binding of protein L to Ig of important laboratory animal species such as the mouse, the rat and the rabbit. The affinity constants for the interactions between protein L and polyclonal IgG of these species were 2.6 × 109, 3.9 × 108 and 7.4 × 107, respectively. In non‐human species, the binding of protein L was also found to be mediated through Ig light chains, and the results demonstrate the potential value of protein L as an immunochemical tool.
Anti‐Interleukin‐2 Receptor Monoclonal Antibody Therapy Supports a Role for Thl‐Like Cells in HgCl2‐Induced Autoimmunity in Rats
Authors: DUBEY D. , KUHN J. , VIAL M. C. , DRUET P. , BELLON B.
Published: July 2006

Brown‐Norway (BN) rats injected with HgCl2 develop an autoimmune disease characterized by a T dependent polyclonal B‐cell activation. Increase in major histocompatibility complex class II molecule expression on B cells concomitant with enhancement of serum IgE concentration supports the involvement of the T helper 2 (Th2)‐like subset in the induction of the disease. The mercury disease is autoreguiated and does not develop in Lewis (LEW) rats. Considering the reciprocal regulation, well defined in mice, between the Th1 and Th2 subsets, we addressed the role of the Thl‐like subset in this disease. Brown‐Norway and LEW rats injected with HgCl2 were treated wilh NDS61, a mouse anti‐ral‐IL‐2R MoAb that blocks mainly Th1 cells. Data reported herein show that: (1) HgCl2 treatment does not modify either the percentage of IL‐2R+ cells or IL‐2R expression in both BN and LEW rats; (2) treatment of BN rats with NDS61 MoAb does not modify the induction phase of the mercury disease but delays in parl the regulation phase; (3) such a treatment leads lo some immune abnormalities in LEW rals; (4) HgCl2 markedly potentiates the anti‐mouse Ig antibody response in BN rats which probably limits the effect of this treatment.

This study supports a role for the Th1‐like subset in HgCl2‐induced auloimmunity in the rat.
Cytotoxic T‐Cell Clones Isolated from Ovarian Tumour Infiltrating Lymphocytes Recognize Common Determinants on Non‐Ovarian Tumour Clones
Authors: IOANNIDES C. G. , FISK B. , POLLACK M. S. , FRAZIER M. L. , WHARTON J. TAYLOR , FREEDMAN R. S.
Published: July 2006

CTL‐TIL lines have been developed from tumour infiltrating lymphocytes (TIL) from the ascites of patients with ovarian carcinoma, and used to investigate whether common tumour antigens are expressed on allogeneic ovarian tumours epithelial tumour lines derived from colon and pancreatic carcinoma. Three CTL lines expressed preferential cytolytic activity against autologous tumour cells and against certain allogeneic ovarian tumour cells that shared HLA‐A2 molecules. Analysis of the target specificity of these CTL lines indicated that they also lysed human colon and pancreatic tumour lines sharing HLA‐A2. CTL‐TIL clones isolated from these lines were found to lyse HLA‐A2+ ovarian, colon and pancreatic tumours, and to recognize clonally distributed common epitopes on pancreas and colon tumour clones. These results indicate that shared tumour antigens can he found among tumours of common epithelial cell origin. These results indicate a novel class of T‐cell‐definable tumour antigens recognized by tumour‐reactive CTL on human tumours and may be significant for understanding of cellular immunity in ovarian cancer, identification of CTL‐defined tumour antigens and future adoptive specific immunotherapeutic approaches in ovarian cancer.
The CD26 Antigen is Coupled to Protein Tyrosine Phosphorylation and Implicated in CD16‐Mediated Lysis in Natural Killer Cells
Authors: MADUEÑO J. A. , MUÑOZ E. , BLAZQUEZ V. , GONZALEZ R. , APARICTO P. , PEÑA J.
Published: July 2006

The levels of CD26 expression, their capacity to induce protein tyrosine phosphorylation and their functional implication in natural killer (NK) cytolysis have been studied. It was found that only a small fraction (12–15%) of peripheral NK cells expresses CD26 compared with the high expression (99%) found in NK clones. The protein tyrosine phosphorylation mediated by means or CD26 activation was studied in NK cells treated with the anti‐CD26 MoAb 134–2C2, and two new proteins of 50 and 21 kDa appeared phosphorylated in tyrosine residues. To study the influence of CD26 antigen in NK lysis, we analysed the lytic capacity of NK cells stimulated with different anti‐CD26 MoAbs or after separation into CD26+ and CD26− subsets and using K562 as target cells. Under these conditions, no differences were found in the chromium release by the target cells. Redirected lysis through CD16 was also measured by arming the effector cells (CD26+ and CD26−) with anli‐CD16 antibody and using K562 as target cells. It was found that CD26− cells showed significantly less CD16‐dependent lysis than CD26+ cells. These results indicate that CD26 is related to the CD16‐dependent lysis but not to NK cytolysis which may be caused by mediation of protein tyrosine phosphorylation.
Differences in the Rate of Intracellular Killing of Catalase‐Negative and Catalase‐Positive Listeria monocytogenes by Normal and Interferon‐Gamma‐Activated Macrophages
Authors: VAN DISSEL J. T. , STIKKELBROECK J. J. M. , VAN FURTH R.
Published: July 2006

Intracellular killing of catalase‐positive bacteria by murine resident macrophages requires the presence of extracellular serum, whereas killing of catalase‐negative bacteria can occur in the absence of serum. To find out whether the intracellular killing of bacteria by rIFN‐γ‐activated macrophages also requires serum stimulation, we investigated the handling of ingested catalase‐negative and ‐positive Listeria monocytogenes by peritoneal macrophages of normal Swiss mice and mice injected i. p. with I × 104U rIFN‐γ 18 h earlier.

In the absence of extracellular serum. rlFN‐γ‐activated macrophages killed ingested catalase‐negative Listeria more efficiently (P<0.01) than normal resident macrophages. Maximal killing of catalase‐negative bacteria by rlFN‐γ‐activated macrophages required an extracellular serum concentration of only 1.0 to 2.5% compared with the 10% needed by normal macrophages. No differences were observed in the rates of intracellular killing of catalase‐positive Listeria by rlFN‐γ‐activated and normal resident macrophages: both populations of macrophages required 10% extracellular serum for maximal killing of these bacteria, and killing was minimal in the absence of scrum. The rIFN‐γ‐activated macrophages displayed enhanced O2‐consumption after stimulation with phorbol myristate acetate and heat‐killed Listeria compared with macrophages from normal mice.

These findings indicate that, under suboptimal stimulation by extracellular serum. rlFN‐γ enhances the intracellular killing of catalase‐negative Listeria which lack endogenous catalase acting as a scavenger of reactive oxygen intermediates. The mechanism underlying the enhancement is probably the amplification of the respiratory burst by IFN‐γ.
Modification of Lymphocyte and Monocyte Functional Activity by Polymorphonuclear Neutrophils in HIV Infection
Authors: GABRILOVICH D. I. , SHEPELEVA G. K. , SEREBROVSKAYA L. V. , AVDEEVA L. A. , POKROVSKY V. V.
Published: July 2006

The aim of this study was to determine whether potymorphonuclear neutrophils (PMN) can modify the immune response in HIV cases. Supernatants of PMN (PMNS) from 33 HIV‐infected patients (16 with lymphoadenopathy syndrome, 17 with AIDS‐related complex) were tested for their influence on the functional activity oflymphocytes and monocytes from 6 healthy donors. PMNS from another 6 healthy donors comprised a control group. It was found that PMNS from HIV‐infected patients, but not from healthy donors, induced suppression oflymphocyte proliferative response and down‐regulation of CD8 receptor expression on lymphocytes. Decrease of NK‐cell cytotoxicity in the presence of PMNS from HIV‐infecled patients was the same as that from healthy donors. PMNS did not influence the production of anti‐HIV antibody by lymphocytes from HIV‐infected patients, as well as non‐specific IgG by lymphocytes from healthy donors. PMNS effect on functional activity of lymphocytes was blocked completely after treatment of PMN by catalase and superoxidedismutase. At the same time PMNS from HIV‐infected patients but not from healthy donors induced increased production of TNF‐a by monocytes and up‐regulation of monoeyte phagoeytosis. These effeets were independent of catalase and superoxide dismutase and were not abrogated by antibody against IL‐1, IL‐8, TNF‐γ, IFN‐γ or IFN‐γ.
Identification of a Novel 27‐kDa Protein from Mycobacterium tuberculosis Culture Fluid by a Monoclonal Antibody Specific for the Mycobacterium tuberculosis Complex
Authors: RAMBUKKANA A. , DAS P. K. , KOLK A. H. J. , BURGGRAAF J. D. , KUIJPER S. , HARBOE M.
Published: July 2006

Mycobacterium tuberculosis antigens inducing species‐specific immune responses are likely to be particularly important for serodiagnosis or for skin testing of tuberculosis. In the present study, we describe the characterization of two novel monoclonal antibodies (MoAbs) A3h4 (IgG2a) and B5gl (IgM) that are directed to M. tuberculosis 27‐kDa and 25‐kDa proteins respectively. Specificity analysis by immunoblotting using 20 different species of mycobacterial sonicates revealed that MoAb A3h4 was specific for M. tuberculosis complex alone while MoAb B5gl showed a limited cross‐reactivity. Direct comparison with previously characterized MoAbs revealed that these MoAbs A3h4 and B5gl defined new antigenic determinants of M. tuberculosis. By using M. tuberculosis complex‐specific MoAb A3h4 we have identified a distinct 27‐kDa protein in the M. tuberculosis H37Rv culture fluid. Since this MoAb did not bind to the previously characterized MPT44, MPT59, MPT45, MPT51 and MPT64 proteins as well as the 23‐kDa superoxide dismutase (SOD) protein of M. tuberculosis, we conclude that MoAb A3h4 recognizes a novel protein in the M. fuberculosis H37Rv culture fluid. Studies of the subccllular distribution of these MoAb‐reaetive proteins indicate that the MoAb A3h4‐reactive 27‐kDa protein is present not only in the culture fluid bnt also in the cytosol and the cell wall of M. tuberculosis. By contrast. B5gl‐reactive protein is mainly a cytosolic protein. When these MoAbs were tested in a previously established ELISA with intact mycobacteria derived from early cultures, only MoAb A3h4 showed the positive reactivity to mycobacteria belonging to the M. tuberculosis complex.

In addition, during the present comparative studies of MoAbs we have also found that the previously described MoAb F116‐5, which is known to recognize the mycobacterial 23‐kDa SOD protein [17], cross‐reacted with the MPT44, MPT59, MPT45 and MPT51 secreted proteins but not with MPT64 and MPB70. These findings indicate that the family of four secreted proteins of M. tuberculosis share a common epitope with M. tuberculosis SOD protein.
Characterization of Two Highly Homologous Autoantibody‐Related VHl Genes in Humans
Authors: YANG P.‐M. , OLEE T. , CARSON D. A. , CHEN P. P.
Published: July 2006

Previously, we showed that the Humhallr rearranged gene was almost identical to the consensus amino acid sequence of several G6 idiotype‐positive rheumatoid factor (RF) heavy chains, and to the VH gene‐encoded region of the fetally expressed 51PI cDNA. The finding led us to suggest that the ha llr‐corresponding germline gene encodes the heavy chains of many human IgM RFs. We now report the isolation of the proposed germline gene, designated Humhv 1051; it is identical to the consensus sequence of the G6 heavy chain V regions. During this experiment, we also isolated unexpectedly an additional VHl gene, termed Humhv 1051K; it differs from hv1051 by one amino acid residue. Importantly, hv1051K is identical to Humha 113, the rearranged VHl gene of a natural anti‐cardiolipin antibody.
IgA and IgG Subclass Deficiency in a Poor Population in a Developing Country
Authors: CASTRIGNANO S. B. , CARLSSON B. , CARNEIRO‐SAMPAIO M. S. , SÖDERSTRÖM T. , HANSON L. Å.
Published: July 2006

The levels of IgG, IgG subclasses, IgM and IgA were determined in serum from 17 patients with IgA deficiency and severe or frequent infections, allergy and/or autoimmunity (median age 7 years, range 2–19), 11 healthy IgA‐deficient adults and 35 controls (median age 7 years, range 2–19). In serum from all groups IgG, IgM and IgA antibodies were determined against β‐lactoglobulin, E. coli O antigens and poliovirus type 1 antigen. In saliva of 15 IgA‐deficient patients and 12 of the controls IgG, IgM and secretory component‐carrying antibodies against E. coli O antigens and poliovirus type I were determined. The majority of the studied individuals lived under poor socio‐economic conditions in Brazil, with consequent heavy microbial exposure. One IgA‐deficient patient with rheumatoid arthritis also had IgG2 deficiency but no infectious problems. Four out of the 35 controls without any obvious infectious problems were found with IgA or IgG subclass deficiency. One of the 11 healthy IgA‐deficient adults was low in the IgG2 subclass, one in IgGl and one in IgG3.

Those with symptomatic IgA deficiency had significantly higher serum IgG than the controls, especially in the age group 6–11 years. This latter group also had significantly increased serum IgG 1 and IgG2 levels when compared with the age‐matched controls. Salivary IgM antibodies to E. coli and poliovirus antigens were significantly higher among the symptomatic IgA‐deficient individuals than among the controls. It is not clear at present whether these increased Ig levels are secondary to frequent infections and/or part of mechanisms that may compensate for the IgA deficiency.
Interleukin‐4 (IL‐4) Enhances Homotypic Adhesion of Activated B‐Chronic Lymphocytic Leukaemia (B‐CLL) Cells via a Selective Up‐Regulation of CD54
Authors: CARLSSON M. , SÖDERBERG O. , NILSSON K.
Published: July 2006

It is well established that cell‐to‐cell contact modifies cytokine signalling but little is known on the role of homotypic cell adhesion for proliferation and differentiation of B cells. Homotypic adhesion involves mainly the interaction between the adhesion molecules Leukocyte Function Antigen‐1 (LFA‐1) and its ligand CD54 (ICAM‐1). A well‐characterized B‐chronic lymphocytie leukaemia (B‐CLL) clone (1–83) was used as a source of monoclonal B cells inducible to DNA synthesis and differentiation by using 12‐O‐tetradecanoyl‐phorbol‐13‐acetate(TPA) in combination with intcrleukin‐4 (IL‐4) and thioredoxin(Trx)‐containing supernatant from a T‐cell hybridoma (BSF‐MP6). This paper shows that IL‐4 alone was able to induce aggregation of B‐CLL cells and to strongly enhance TPA+BSF‐MP6‐induced aggregalion. The results from studying the expression of CD11a and CD18, the two suhunits of LFA‐1, and CD54 during stimulated DNA synthesis and differentiation suggest that IL‐4‐induced. or enhanced, aggregation was mainly mediated by a selective up‐regulation of CD54. It was further demonstrated by antibody blockade to either CD11a, CD18 or CD54 that aggregation could be inhibited without affecting induced DNA synthesis or differentiation.
Transfer of CD8+ T Cells into SCID Mice and Activation of Memory Virus‐Specific Cytotoxic T Cells
Authors: KOS F. J. , MÜLLBACHER A.
Published: July 2006

The requirements for the activation of naive and memory CD8+ cytotoxic T(Tc) cells into effector virus‐specific Tc cells after transferring them into SCID mice were investigated. SCID mice reconstituted with splenocytes or purified CDS+ T cells from naive or influenza‐immune syngeneic mice and immunized with influenza virus generated effector Tc cells specific for influenza virus‐infected target cells in vitro. The kinetics of Ihe response varied between those two populations. The generation of effector Tc cells after transfer of memory CD8+ T cells indicates that there exists no absolute requirement for “help” in the activation of memory virus‐immune Tc cells. However, under the conditions described here the in vitro immunogenic peptide NPP derived from influenza nucleoprotein is not sufficient to elicit a response in vivo.
Activated Natural Killer Cells Suppress Myelopoiesis in Mice with Severe Combined Immunodeficiency
Authors: PISA P. , SITNICKA E. , HANSSON M.
Published: July 2006

The in vivo effect of natural killer (NK) cell activation on aulologous myelopoiesis was studied in an environment deficient of functional Tand B cells. Administration of 3.6‐bis[2‐(Dimethylamino)‐ethoxy]‐9H‐xanthen‐9‐one dihydrochloride) Tilorone) or recombinant interleukin‐2 (rIL‐2) to mice with severe combined immunodeficiency (C. B. ‐I7 scid/scid) resulted in an increase in YAC‐1 lysis by their splenocytes as well as bone marrow cells. Recombinant IL‐2 furthermore led to a fivefold increase in the cellularity of the spleen. When assayed against human NK/lymphokine‐activated killer (LAK) target, K562 cell line. the IL‐2‐activated mouse cells exhibited no cytotoxicity across the species barrier. Both agents induced a profound suppression of myelopoietic progenitor cells as measured in a 7‐day granulocyte‐macrophage colony forming cell (GM‐CFC) assay. We conclude that the presence of neither functional T nor B cells is necessary for NK cells to mediate inhibition cf myelopoiesis in the autologous host.
Schistosoma mansoni Egg‐Primed ThO and Th2 Cells: Failure to Down‐regulate IFN‐γ Production Following In Vitro Culture
Authors: VELLA A. T. , PEARCE E. J.
Published: July 2006

Schistosoma mansoni eggs induce a rapid and pronounced Th response which, based on cytokine secretion patterns, at day 3 post priming is Th0)‐like and at day 10 is Th2‐like. To establish whether or not the day‐3 cells have been programmed in vivo to develop into Th2 cells, they were cultured for 7 days to become in vitro equivalents of day‐10 in vivo cells. Following this culture period, the population was approximately 75% CD4+, 22% CD8+, 6% B220+ and capable of producing IL‐2, IFN‐γ, IL‐4, ‐5 and ‐10 upon stimulation. This Th0‐like status was confirmed by the observations that in response to mitogen IL‐4 and IFN‐γ production are both CD4+ ‐cell dependent and that IFN‐γ and IL‐4 are produced concomitantly by single cells. These data suggest that ThO cells persist in vivo, but are incapable of secreting IFN‐γ at day 10 due loan inhibitory factor which does not develop or is labile in vitro. This concept is supported by ihc surprising observation that day‐10 LN cells, which are Th2‐like immediately ex‐vivo, rapidly gain the ability to secrete IFN‐γ following a short period of culture.
Experimental Allergic Bronchopulmonary Aspergillosis in the Mouse: Immunological and Histological Features
Authors: WANG J. M. , DENIS M. , FOURNFER M. , LAVIOLETTE M.
Published: July 2006

C57BL/6 mice treated with intranasal instillation of 100 μg of Aspergillus antigen three times a week developed a pulmonary eosinophilia, observed in the bronchoalveolar lavage (BAL) and on hislopatholo‐gical examination. At week 3, the instillation of Aspergillus antigen provoked a 10‐fold increase in the BAL cell number and eosinophils were the predominant inflammatory cells (66.4′%,). Histopathological findings showed focal alveolar lesions with pcribronchial and perivascular infiltration of lymphoid cells, numerous eosinophils, epithelioid cells, and granulomus with giant cells. Increases in total IgF. and IgG1 levels in BAL fluid (33‐fold and 14‐fold) and serum (67‐fold and 8‐fold) were observed also (P<0.05). IgGl specific to Aspergillus fumigatus (Af) was detected only in the antigen‐treated mice.

At 12 weeks, there was a persistent but less intense eosinophilia both in BAL and on histopathological examination accompanied by steadily elevated total IgE and total FgGl and a higher level of specific IgGl‐Af in BAL fluids and sera. No bronchocentric granulomatosis, mucoid impaction nor bronchiecta‐sis could be observed.

Data from the study described here showed that in mice repeated exposure to Aspergillus antigen leads to a strong inflammatory pulmonary response, characterized by remarkable pulmonary eosinophilia and elevations of total IgE, total IgG 1 and specific TgG1‐Af in both BAL and serum, which are the hallmarks of human allergic bronchopulmonary aspergillosis also. However, this inflammation did not induce the chronic histological features of the human disease.
Tumour Growth Causes Suppression of Autoreactive T‐Cell Proliferation by Disrupting Macrophage Responsiveness to Interferon‐γ
Authors: ALLEVA D. G. , BURGER C. J. , ELGERT K. D.
Published: July 2006

Normal immune homeostasis is regulated partly by a small population of CD4+ T cells that react to autologous major histocompatibility complex class‐II molecules on self‐cells. Decreased autoreactive T‐cell responses are associated with cancer. Tumour growth causes syngeneic macrophages (Mø) to suppress autoreactive T‐cell proliferation by decreasing Mø class‐II expression and increasing Mø production of the suppressor molecule prostaglandin E2 (PGE2). Because interferon‐γ (IFN‐γ) is a potent Mø activation molecule which regulates both Mø PGE2 and class‐II expression, the effects of IFN‐γ on tumour‐induced suppression of autoreactive T‐cell proliferation were investigated. Exogenous IFN‐γ increased normal host (NH) CD4+ autoreactive T‐cell proliferation stimulated by syngeneic NHMø but decreased proliferation stimulated by tumour‐bearing host (TBH) Mø. Antibody (Ab) neutralization of endogenous IFN‐γ activity reduced TBH Mø‐mediated suppression. Kinetic studies showed that endogenous IFN‐γ suppressor activity was not exclusive during T‐cell activation. Indomelhacin treatment blocked IFN‐γ‐induced suppression in TBH Mø‐T cell cultures. TBH Mø‐T cell cultures contained significantly more PGE2 than those containing NH Mø. Exogenous IFN‐γ increased early PGE2 production in TBH Mø cultures but decreased production in NHMø cultures. The Ab‐mediated neutralization of endogenous transforming growth factor‐β or tumour necrosis factor‐x reduced TBH Mμ‐mediated suppression and blocked IFN‐γ‐induced suppression. Short‐term treatment of Mμ with IFN‐γ before their addition to T cells caused TBH Mμ to stimulate T‐cell proliferation, which suggests that early suppressor molecule production by TBHMø inhibits synthesis or activity of IFN‐γ‐induced stimulatory monokines. These results show that tumour growth causes Mø to suppress autoreactive T‐cell responses by allowing IFN‐γ to induce Mø suppressor molecules, which block production or activity of stimulatory monokines.
Tumour Promoters/Protein‐Kinase C Activators Augment the Survival and Function of Human Monocyte‐Derived Macrophages in Long‐Term Cultures
Authors: MARKOVICH S. , KOSASHVILLI D. , RAANANI E. , ATHAMNA A. , O'BRIAN C. A. , KEISARI Y. K.
Published: July 2006

In this study the effect of various Protein kinase C (PKC) aetivators/tumour promoters on the maturation and activity of human peripheral blood monocytes was examined. Monocytes were cultured in the absence or presence of various PKC activators for up to 2 weeks, and examined for the number of adherent cells, expression of myeloperoxidase enzymes, CDI4 antigens, mannose/N‐aeetylglucosamine (Man/GlcNAc) receptors, and the production ofTNF‐γ. The presence of PKC activators in cultures of monocyte‐derived macrophages (HuMoDM) prevented the loss in the number of initially plated monocytes, otherwise observed in long‐term tissue cultures with time of incubation. This effect of PKC activators on monocyte survival was diminished in the presence of PKC inhibitors. HuMoDM obtained in the presence ofPKC activators maintained a normal differentiation pattern, as was evident by the loss of granular myeloperoxidase enzytnes and CDI4 antigens, and the acquisition of metnbrane Man/GlcNAc receptors. HuMoDM which differentiated in the presence of PKC activators also released TNF‐γ in comparable amounts to freshly harvested human monoeytes. PKC activators/tumour promoters augmented the viability of long‐term cultures of human monoeyte‐derived macrophages. Such macrophages may facilitate cell and molecular biology studies of differentiated human macrophages.
Endogenous IL‐10 and IFN‐γ Production Controls Thymic Cell Proliferation in Mice Acutely Infected by Trypanosoma cruzi
Authors: DE MORAES M. D. C. LEITE , MINOPRIO P. , DY M. , DARDENNE M. , SAVINO W. , HONTEBEYRIE‐JOSKOWICZ M.
Published: July 2006

Thymocytes from mice with experimental Trypanosoma cruzi infection respond poorly to Con‐A stimulation. However, the proliferative capacity of these cells is not impaired, as demonstrated by the fact that at high doses, exogenous rIL‐2 restores thymidine uptake. This finding could be explained either by insufficient IL‐2 production or by the appearance of inhibitory factors during T. cruzi infection. This paper shows that in response to Con A, IL‐2 production is decreased in the model. Furthermore, the whole profile of cylokine production is modified, with a striking increase in IL‐10, IFN‐γ, IL‐4, IL‐5 and IL‐6 production. The results indicate that IL‐10 it plus IFN‐γ are responsible for the decrease in the Con A induced proliferation since a normal proliferative response as well as normal IL‐2 production can be restored if both cytokines are neutralized by adding their monoclonal antibodies (MoAbs). Evidence is provided also for an enhanced non‐specific cytotoxicity of thymic cells from infected mice that might involve IL‐4, IL‐5 and IL‐6. This is the first study demonstrating an alteration of thymic cell function by T. cruzi infection which results from overstimulation of IL‐10 and IFN‐γ production.
Down‐regulation of L‐selectin Surface Expression by Various Leukocyte Isolation Procedures
Authors: STIBENZ D. , BÜHRER C.
Published: July 2006

L‐selectin, a cell surface glycoprotein expressed on lymphocytes, granulocytes, and monocytes, has been implicated in lymphocyte homing and extravasation of phagocytic leukocytes into areas of inflammation. Considerable differences of L‐selectin expression among various individuals has been reported, with clinical correlations to perinatal events, maturation, and circadian rhythm. In this study, L‐selectin expression of various white blood cells was found to be differentially sensitive to ficoll‐hypaque or percoll density gradient centrifugation. After density gradient centrifugation, a significant loss of median monocyte L‐selectin expression was observed when compared to time and temperature‐matched controls or results obtained by whole blood incubation with anti‐L‐selectin monoclonal antibodies followed by simultaneous leukocyte fixation and red cell lysis. Mock treatment itself was associated with a variable L‐selectin loss of monocytes but not lymphocytes or granulocytes. Ficoll‐hypaque or percoll density gradient centrifugation resulted in significant L‐selectin down‐regulation of lymphocytes while granulocytes separated from lymphocytes and monocytes by ficoll‐hypaqus or percoll retained full L‐seleclin surface reactivity. L‐selectin downregulation was seen also after colloid sedimentation with hydroxy‐ethyl starch. It is concluded that unseparated blood should be used for measuring L‐selectin expression.
Target‐Cell Sensitivity to Natural Killer‐Cell Lysis is Determined by the Expression of a Novel Antigen in Conjunction with Major Histocompatibility Complex Class‐I Molecules
Authors: HARRIS D. T. , JASO‐FRIEDMANN L. , EVANS D. L.
Published: July 2006

Recently, a panel of monoclonal antibodies (MoAbs) was developed that identified a novel tumour‐cell antigen conserved across species (mouse, rat and man). Fluorescence‐activated cell sorter (FACS) analysis demonstrated that this antigen was expressed at highest levels on human tumour cell lines sensitive to natural killer (NK)‐cell lysis. These MoAbs inhibited NK cell lysis of K562 target cells (by up to 90%), as well as a variety of other NK‐sensitive target cells. Biochemical analyses revealed that the MoAbs reacted with a polypeptide of 42 kDaitons, distinct from other known cell surface antigens [1]. Now the expression of this antigen has been analysed further with a panel of 24 tumour cell lines to determine its role in NK cell function. The expression of target cell major histocompatibility complex (MHC) molecules in conjunction with sensitivity to NK cell lysis was examined also. For each of the 24 cell lines it was found that the level of expression of the novel target cell antigen determined the sensitivity of the celt line to NK cell lysis. However, the level of MHC antigen expression could modulate target cell sensitivity to NK cell lysis, in that high levels of MHC class‐I molecule expression resulted in a target cell that was insensitive to NK cell lysis regardless of the level of expression of the novel antigen. Thus, for most transformed cell lines, sensitivity to NK cell lysis appeared to be determined by the expression and levels of the novel antigen in association with MHC class‐I molecules.
The Primary Structure of Serum Amyloid A Protein in the Sheep: Comparison with Serum Amyloid A in Other Species
Authors: SYVERSEN P. V. , JUUL J. , MARHAUG G. , HUSBY G. , SLETTEN K.
Published: July 2006

Serum amyloid A (SAA) protein was isolated from acute phase sheep sera by ultracentrifugation, gel filtration and ion‐exchange chromatography. The purified protein was characterized by sodium dodecylsulfate polyacrylamidc gel electrophoresis (SDS‐PAGE), isoelectric focusing, amino acid composition and Edman degradation. Protein SAA sheep consists of 112 amino acid residues and has a blocked N‐terminus. The amino acid sequence showed a high degree of homology with SAA proteins from other species, especially at positions 32 to 54, indicating that this particular part of the protein is important for its function. When compared to human protein SAA, nine inserted amino acids could be demonstrated, located in regions 69 to 77. Similar observations have been seen in cow, horse, dog, cat, and mink protein SAA. Heterogeneities were found in positions 28, 55, 63, 64, 66, 75, 77, 78, 80 and 89. Positions 63, 64, 66, 75, 77, 78 and 80 revealed the existence of a minor gene product of protein SAA sheep. The minor variant of protein SAA sheep is identical in these positions with the corresponding positions in protein SAA cow. By comparing the amino acid sequences of the different SAA proteins, two separate branches in the evolutionary pattern of protein SAA appear. One of the branches includes the species with the insertion which represents also one of the more heterogeneous part of the protein.
A Murine Monoclonal Multireactive Immunoglobulin Kappa Light Chain
Authors: MAHANA W. , JACQUEMART F. , ERMONVAL M.
Published: July 2006

N12.12 is a monoclonal immunoglobulin (Ig) kappa light chain (KLC) secreted by a B‐celI hybridoma derived from spleen cells of a normal SJA mouse. No heavy chain was detected in the culture supernatant of this hybridoma using an enzyme immunoassay (EIA) and after polyacrylamide gel eleclrophoresis (SDS‐PAGE) of the 35S‐methionin biosynthetically labelled proteins secreted by the cells. It was shown that NI2. I2 KLC reacted with mouse actin, trinitrophenylated bovine serum album in (TNP25‐BSA) and weakly with bovine myoglobin. The binding of the NI2.12 ‘monoclonal antibody’ to mouse actin or to TNP25‐BSA was inhibited specifically by both antigens with a dissociation constant (KD) for binding to mouse actin of 10−7M. The results indicate that a free KLC can bind both to mouse and to non‐mouse molecules, thus exhibiting binding characteristics usually attributed to natural multireaetive antibodies.
Characterization of an Early Activation‐Dependent Antigen on Lymphocytes Defined by the Monoclonal Antibody BL‐Ac(F2)
Authors: EICHLER W. , AUST G. , HAMANN D.
Published: July 2006

A novel activation‐dependent lymphocyte cell‐surface antigen which is recognized by a MoAb, BL Ac(F2), is described. Although not found on resting lymphocytes the antigen is induced rapidly wiihin 2–4 h following stimulation of the cells using mitogens or antibodies against the T‐eell CD3 antigen and sIgM on B cells, respectively. Immunopreeipitation and Western Blotting indicated that the MoAb recognizes a molecule in a range of 78 85 kDa. Beyond its activalion‐dependent expression on lymphocytes the antigen was detected also on myelo‐monocytic cells. Expression kinetics and cellular distribution of this molecule suggest that it is distinct from previously described activation‐dependent cell‐surface antigens sueh as CD69, CD25 and 4F2.
Signal Transduction via MHC Class‐I Molecules in T cells
Authors: Tscherning T. , Claësson M. H.
Published: July 2006

The data reviewed in this paper, suggest that besides their role in presentation of antigenic pcptides to T cells, MHC‐I molecules may play an important role in the fine‐tuning of signal transmission across the cell membrane by their associations with a variety of cell‐surface receptors regulating cell growth and differentiation.
Germline‐Encoded IgG Antibodies Bind Mouse Cartilage In Vivo: Epitope‐ and Idiotype‐Specific Binding and Inhibition
Authors: MO J. A. , SCHEYNIUS A. , NILSSON S. , HOLMDAHL R.
Published: July 2006

Autoantibodies specifie for type‐II collagen (CII) occur in mice and rats with collagen‐induced arthritis (CIA). The binding in vitro and in vivo of mouse monoclonal antibodies (MoAbs) specific for separate epitopes in CII have been investigated. Two‐day‐old mice were injected intraperitoneally (i. p.) with the anti‐CII antibody CIID3 in both unlabelled and biotinylated form. It was found that antibodies binding to the same epilope in CII in vivo can inhibit others from binding in an epitope‐specific fashion. The binding in vivo and in vitro of anti‐CII antibodies could be inhibited also by an anti‐idiotypic rat antiserum produced against the D3 antibody. The anti‐idiotypic antiserum inhibited the binding of the antibody D3 and the idiotypically related antibody C2. The cDNA's of anti‐CII antibodies D3, C2, and F4 were sequeneed and found to contain germline encoded V‐genes. apparently without somatic mutations. The variable heavy chain of D3 and C2 both expressed the same VH rearrangement, confirming that they share idiotypes. This report demonstrates that CII‐specific germline‐encoded IgG autoantibodies bind specifically to normal cartilage in vivo via their combining site.
Human NK Cells Expressing α4β1/β7 Adhere to VCAM‐1 Without Preactivation
Authors: PINOLA M , SAKSELA E. , TIlSALA S. , RENKONEN R.
Published: July 2006

The authors demonstrate that resting CD56+/CD3− NK cell adhesion to the endothelial VCAM‐1 is over three‐fold higher than CD56−/CD3 + T‐cell adhesion. T‐cell, but not NK‐cell adhesion, to VCAM‐1 is enhanced significantly by stimulation. The expression of VCAM‐I receptor subunits α4 and β1 on both effector cells remains unchanged upon stimulation. A subpopulation of NK cells, as well as of T cells, was found to express β7, whose expression was not altered upon stimulation. The authors conclude that the adhesive properties of the same receptor structures on these distinct cell populations are regulated in a different manner, according to the specific functions of the effector cells of the immune system.
Ligation of Leukocyte Function‐Associated (LFA) Molecule‐1 Provides an Accessory Signal for T‐Cell Activation with Pokeweed Mitogen
Authors: WALLAYS G. , CEUPPENS J. L.
Published: July 2006

The ligation between Leucocyte‐Function‐Associated Molecule I (LFA‐1) and Intercellular Adhesion Molecules (ICAM) is thought to be an important component in the stimulatory interaction between antigen‐presenting cells (APC) and T cells. Similar to antigenic stimulation, T‐cell stimulation with pokeweed mitogen (PWM) is highly dependent on monocytes as accessory cells. This is partly a consequence of the requirement for mitogen presentation by the monocytes. The study described here addressed the question of whether LFA‐1 ligation by accessory cells influences the activation of T cells with PWM. To avoid multiple costimulatory interactions between T cells and monocytes. experiments were performed with purified T cells, which were stimulated with PWM bound on autologous red blood cells (PWM‐RBC). Binding on the RBC substituted partly for PWM presentation by the monocytes. Anti‐LFA‐1 MoAbs were presented in the immobilized form in order to mimick LFA‐1 ligation by cell‐bound ICAM. Three out of three different MoAbs against the β‐chain of the LFA‐1 molecule (CD18) and two out of three MoAbs against the α‐chain (CD11a) had an enhancing effect on T‐cell proliferation, Proliferation was increased further by simultaneous addition of interleukin (IL)‐1 β and IL‐6. Ligation of the LFA‐1 molecule was found to enhance IL‐2 production and tumour necrosis faclor‐α (TNF‐α) production. The results suggest that interaction of LFA‐1 with ICAM on the monocytes contributes to the accessory signal activity of monocytes in T‐cell activation with PWM.
Functional and Biochemical Properties of a Mouse Placental Immunoregulatory Factor
Authors: BOBÉ P. , BLEUX C. , KANELLOPOULOS‐LANGEVIN C.
Published: July 2006

The authors have a long standing interest in immune regulations which control the absence of rejection of a semi‐allogeneic fetus by the mother. A previous work described a soluble 40 kDa factor extracted from mouse placenta and capable of inhibiting secondary immune responses in vivo. The present paper reports the following on its mode of action in vivo: (1) it is active even in a fully allogeneic host; (2) it can be administered i. v. or i. p. along with antigen; and (3) the injections of factor and antigen must not be more than 2 days apart for maximum efficacy. Moreover, the results of the study described here indicate also that this factor is a concanavalin A‐binding giycoprotein, sensitive to heat and pronase, and different from interleukin 10 (IL‐10).

Thus, this placental factor appears to be different from previously described immune regulators such as IL‐10 and could contribute significantly to immune regulations at the level of the placenta.
IgM and IgG Subclass Distribution of Human Anti‐Ro/SSA 60 kDa Autoantibodies
Authors: WAHREN M. , RINGERTZ N. R. , PETTERSSON I.
Published: July 2006

The Ro/SSA and La/SSB antigens are common targets for autoantibodies found in the sera of patients with Sjögren's syndrome and SLE. The anti‐Ro/SSA and anti‐La/SSB antibodies often appear together but are not cross‐reactive. This paper describes the humoral autoimmune response to the Ro/SSA 60 kDa protein moiety with respect to the presence of IgM and IgG1‐4 antibodies. IgM antibodies to the Ro 60 kDa protein coexisted with IgG anti‐Ro 60 kDa antibodies in nearly half of the sera. A similar fraction also contained IgM anti‐La/SSB antibodies. The frequency of sera with IgM antibodies of both specificities was that expected from random overlap.

A predominating igGl anti‐Ro 60 kDa response was found in all patients, but anti‐Ro 60 kDa antibodies of the other IgG subclasses were present also in a high number of sera. This is in contrast to the reported IgG subclass distribution of anti‐La/SSB antibodies.

Mapping of IgM and IgG 1–4 antibody recognition of different parts of the Ro 60 kDa protein was also performed. IgM and IgGl‐4 antibodies of all sera reacted with the central part of the Ro 60 kDa protein, encompassing amino acid residues 181–320.
VH‐Gene Family Dominance in Ageing Mice
Authors: VIALE A.‐C. , CHIES J. A. B. , HUETZ F. , MALENCHERE E. , WEKSLER M. , FREITAS A. A. , COUTINHO A.
Published: July 2006

The cellular composition and Vn‐gene family repertoire were compared in different B‐cell compartments from young adult (8–12 weeks) and old (18–24 months) C57BL/6 and BALB/c mice. Ageing mice were found to have a higher frequency of peripheral mature B cells utilizing genes from a single VH‐gene family. While in each individual old C57BL/6 mice cells expressing the VH J558 gene family consistently were over‐represented, a marked individual variation was observed in old BALB/c mice with increased frequency of either the Vh J558, Q52 or J606 families. Aged mice were found also to have a reduced number of bone‐marrow pre‐B cells and an augmented number of splenic Ig‐secreting cells. These results suggest that old mice express less diversified antibody repertoires possibly as a consequence of reduced input from precursors and increased peripheral selection, which may be responsible for the progressive establishment of immunodeficiency.
Increased Expression of VLA‐5 Adhesion Molecules on Synovial Fluid T Lymphocytes in Chronic Polyarthritis: a Consequence of T‐Cell Activation
Authors: WALLE T. K. , HELVE T. , VIRTANEN† I. , KURKI P.
Published: July 2006

This study focuses on the consequences of T‐lymphocyte activation in chronic polyarthritis in terms of expression of cell surface receptors interacting with extracellular matrix (ECM). The expression of the VLA group of integrins was studied on in vitro‐stimulated peripheral‐blood T cells, and on peripheral‐blood and synovial‐fluid mononuclear cells (MNC) of patients with polyarthritis. The VLA expression was measured by flow cytometry using monoclonal antibodies (MoAbs) against α‐subunits of the VLA family. VLA‐α4 and VLA‐α5, but not VLA‐α1, were expressed on a major fraction of unstimulated peripheral‐blood T cells both in the patients with polyarthritis and in healthy individuals. Two distinct populations, VLA‐α5‐high and VLA‐α5‐low, were found in resting peuplieral‐blood T lymphocytes. Two days after stimulation by phorbol 12‐myristate 13‐acetatc (PMA) and concanavalin A, most T cells became VLA‐α5‐high. In patients with chronic polyarthritis, the expression of VLA‐α1 and VLA‐α5 was always higher on synovial‐fluid T cells than on peripheral‐blood T cells. These results give further support to the hypothesis that upon activation the induction of the VLA adhesion‐molecule expression may be a factor contributing to the accumulation of T cells in the inflamed synovium.
Lectin Receptors on IgA Isotypes
Authors: WOLD A. E. , MOTAS C. , SVANBORG C. , MESTECKY J.
Published: July 2006

It has been shown previously that secretory IgA interacts with the mannose‐specific lectin of Escherichia coli. The purpose of the study described here was to evaluate whether the N‐linked oligosaccharide chains of the human IgA isotypes IgA1 and IgA2 differ in lectin receptor activity. A range of plant lectins specific for N‐linked oligosaccharide chains were tested for their ability to precipitate IgA1 and IgA2 myeloma proteins, secretory IgA and free secretory component. IgA2 myeloma proteins reacted more strongly than IgA1 with the mannose‐specific lectin ConA, whereas IgA1 myeloma proteins reacted more strongly than IgA2 with two galactose‐specific lectins, Ricinus communis agglutinin I and Abrus precatorius agglutinin. This suggests that IgA2 possesses a larger proportion of short truncated complex type oligosaccharide chains and/or oligomannose type chains than IgA1. Further. IgA2 reacted more strongly than IgA1 myeloma proteins with Lens culinaris (lentil) lectin, and Pisum sativum (pea) lectin, suggesting that IgA2 exposes more of short, complex type chains fucosylated on the core than IgA1. The differences demonstrated in receptor activity between IgA1 and IgA2 may be important in their interaction with the microbial flora, as well with endogenous lectins, such as phagocyte receptors.