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The arihritogenic properties of adjuvant oil upon percutaneous administration in DA rats was investigated. Groups of rats were administered single or repeated percutaneous applications of Freund's incomplete adjuvant (FIA) or olive oil on shaved skin with or without prior abrasion of the skin. Control rats were shaved and abrased only. A transient arthritis developed in 8/16 animals after repeated applications of FIA on abrased skin. The incidence of arthritis increased to 7/8 animals when FIA was repeatedly administered via filter paper on abrased skin and covered with a bandage. Histological examination of the arthritic joints showed proliferation of the synovial lining layer, infiltration of mononuclear cells and polymorphonuclear cells in the subsynovial tissue. Some bone and cartilage destruction was also seen. Repeated treatment with olive oil on abrased skin induced joint swelling in 3/15 animals, which did not, however, correspond to any microscopically observable signs of inflammation. Also, a single application of FIA on abrased skin or repeated applications of FIA without abrasion induced arthritis, although with low penetration, whereas control animals had no clinical signs of joint involvement. These findings demonstrate that percutaneous administration of adjuvant oil can cause arthritis in genetically susceptible animals. [ABSTRACT FROM AUTHOR]

This paper demonstrates that CD40 is expressed on rheumatoid synovial pannus and primary fibroblast cell lines established from rheumatoid and osteoarthritic synovium as well as normal skin. Among various tested cytokines, interferon-gamma (IFN-γ) and lo a lower extent, tumour necrosis factor-alpha (TNE-α) were found to upregulate CD40 expression on fibroblasts. Synovial and skin fibroblasts cultured over CD40 Ligand transfected L cells (L-CD40L) demonstrate a CD40 specific increase of DNA synthesis as measured by tritiated thymidine incorporation. Cell-cycle analysis and enumeration of viable cells further show that CD40 induced fibroblast proliferation. Costimulation with L-CD40 L and IFN-γ, resulted in maximal proliferation. Engagement of fibroblasts CD40 increased the IL-l-induced production of granulocyte macrophage-colony stimulating factor and macrophage inflammatory protein-Iα MIP-lα, CD40L activated fibroblasts showed decreased levels of CD40, but only marginal alterations of other cell-surface antigens. Taken together, the present results indicate that fibroblasts express functional CD40 and suggest a possible role of CD40L expressing cells, such as activated T cells and mast cells, in the development of synovium hyperplasia. [ABSTRACT FROM AUTHOR]

Patients affected by AIDS-related complex (ARC) show several immunological abnormalities which may lead to a disregulation of immunosurveillance against viral latent infections. In this paper evidence for Epstein-Barr virus (EBV) reactivation in seven out of eight affected by persistent generalized lymphadenopathy is given. These patients showed either elevated levels of circulating EBNA-positive transformed cells or depressed EBV-specific T cell cytotoxicity, as assessed by the regression assay, or both. A direct involvement of EBV in the pathogenesis of ARC is thus suggested. Natural killer cell activity was found decreased, correlating to the evidence of circulating EBV-infected cells and of impaired EBV-specific immune control. These data provide evidence that, when specific immune mechanisms lose control on ubiquitous latent viruses, the risk for reactivation becomes higher. In the case of EBV, direct evidence of this event is provided by the emergence in the peripheral blood of clones of infected cells with unlimited growth potential. [ABSTRACT FROM AUTHOR]

The presence of J chain in human immunocytes containing various immunoglobulin classes has already been reported and in this paper we investigated the presence of J chain in human myeloma cells using light and electron microscopy. Myeloma cells were positive for cytoplasmic J chain in thirteen cases six of fifteen IgG myeloma, two of seven IgA myeloma, two of nine B J myeloma and three of three primary macroglobulinaemia. None of the four with benign monoclonal gammopathy was positive for J chain. The ultrastructural localization of J chain in IgG myeloma cells was similar to that γ chain, i.e. around the nuclear membrane, in the endoplasmic reticulum (ER) and it the Golgi apparatus. The latter finding is compatible with the presence of J chain in the urine of the same patient. We examined the urine from nine patients with J chain-positive cells and secretion of J chain was confirmed in three patients two with IgG myeloma and one with B J myeloma. In none of twelve in whom the immunocytochemical findings were negative for J chain was there evidence of urinary J chain. [ABSTRACT FROM AUTHOR]

In this paper we report a study of the effects of splenectomy on the immunosuppressive action of essential fatty acids (EFA) which is thought to be mediated through prostaglandins (PG) produced in the spleen. Experimental allergic encephalomyelitis (EAE) was induced in normal, splenectomized and sham splenectomized Lewis rats. EFA were administered orally, the animals in the control groups being treated with liquid paraffin. Treatment with EFA significantly suppressed clinical disease in those animals in which EAE was induced by the inoculation of central nervous system material of guinea-pigs or by passive transfer by Con A-stimulated spleen cells. Splenectomy abrogated the suppressive effect of EFA. This observation, together with previous results showing the abrogation of EFA immunosuppression by an inhibitor of the biosynthesis of PG from EFA, led us to postulate a close relationship between EFA, PG and a splenic factor suppressing immunopathological mechanisms in EAE. [ABSTRACT FROM AUTHOR]

This paper describes further confirmation of the successful application of the macrophage electrophoretic mobility (MEM) test to the detection of malignant disease. Results from fifty-one patients and eighteen controls are presented. The apparatus and technique used for the measurement of macrophage elctrophoretic mobility differed from those previously used in other investigations. Further information is presented on the nature and behaviour of macrophage slowing factor(s), and experiments concerning the possible use of cells other than guinea-pig macrophages as indicators of slowing factor production are also described. [ABSTRACT FROM AUTHOR]

The article presents various research papers related to inhibitory proteins and non-lethal effects, published in an earlier issue of the journal "Clinical & Experimental Immunology". One of the abstracts talk about role of inhibitory membrane proteins in the complement dependent killing of trophoblast cells. Trophoblast cells are known to be highly resistant to killing by decidual NK cells. HRF20 is deficient in a patient suffering from paroxysmal nocturnal hemoglobinuria. This deficiency in HRF20 is not only on blood cells but also other tissues including endothelial cells and peripheral nerves.

Summary: Pneumococcal infections cause a large global health burden, and the search for serotype‐independent vaccines continues. Existing conjugate vaccines reduce nasopharyngeal colonization by target serotypes. Such mucosal effects of novel antigens may similarly be important. CD4+ Th17 cell‐dependent, antibody‐independent reductions in colonization and enhanced clearance have been described in mice. Here we describe the evaluation of T helper type 17 (Th17) cytokine responses to candidate pneumococcal protein vaccine antigens in human cell culture, using adenoidal and peripheral blood mononuclear cells. Optimal detection of interleukin (IL)‐17A was at day 7, and of IL‐22 at day 11, in these primary cell cultures. Removal of CD45RO+ memory T cells abolished these responses. Age‐associated increases in magnitude of responses were evident for IL‐17A, but not IL‐22, in adenoidal cells. There was a strong correlation between individual IL‐17A and IL‐22 responses after pneumococcal antigen stimulation (P < 0·015). Intracellular cytokine staining following phorbol myristate acetate (PMA)/ionomycin stimulation demonstrated that  > 30% CD4+ T cells positive for IL‐22 express the innate markers γδT cell receptor and/or CD56, with much lower proportions for IL‐17A+ cells (P < 0·001). Responses to several vaccine candidate antigens were observed but were consistently absent, particularly in blood, to PhtD (P < 0·0001), an antigen recently shown not to impact colonization in a clinical trial of a PhtD‐containing conjugate vaccine in infants. The data presented and approach discussed have the potential to assist in the identification of novel vaccine antigens aimed at reducing pneumococcal carriage and transmission, thus improving the design of empirical clinical trials. [ABSTRACT FROM AUTHOR]

Summary: All organisms are exposed constantly to a variety of infectious and injurious stimuli. These induce inflammatory responses tailored to the threat posed. While the innate immune system is the front line of response to each stimulant, it has been considered traditionally to lack memory, acting in a generic fashion until the adaptive immune arm can take over. This outmoded simplification of the roles of innate and acquired arms of the immune system has been challenged by evidence of myeloid cells altering their response to subsequent encounters based on earlier exposure. This concept of ‘innate immune memory’ has been known for nearly a century, and is accepted among myeloid biologists. In recent years other innate immune cells, such as natural killer cells, have been shown to display memory, suggesting that innate immune memory is a trait common to several cell types. During the last 30 years, evidence has slowly accumulated in favour of not only haematopoietic cells, but also stromal cells, being imbued with memory following inflammatory episodes. A recent publication showing this also to be true in epithelial cells suggests innate immune memory to be widespread, if under‐appreciated, in non‐haematopoietic cells. In this review, we will examine the evidence supporting the existence of innate immune memory in stromal cells. We will also discuss the ramifications of memory in long‐lived tissue‐resident cells. Finally, we will pose questions we feel to be important in the understanding of these forgotten cells in the field of innate memory. [ABSTRACT FROM AUTHOR]

Summary: Acute inflammation is a complex and tightly regulated homeostatic process that includes leucocyte migration from the vasculature into tissues to eliminate the pathogen/injury, followed by a pro‐resolving response promoting tissue repair. However, if inflammation is uncontrolled as in chronic diseases such as rheumatoid arthritis (RA), it leads to tissue damage and disability. Synovial tissue inflammation in RA patients is maintained by sustained activation of multiple inflammatory positive‐feedback regulatory pathways in a variety of cells, including myeloid cells. In this review, we will highlight recent evidence uncovering biological mechanisms contributing to the aberrant activation of myeloid cells that contributes to perpetuation of inflammation in RA, and discuss emerging data on anti‐inflammatory mediators contributing to sustained remission that may inform a novel category of therapeutic targets. [ABSTRACT FROM AUTHOR]

Cellular adjuvants such as dendritic cells (DC) are in the focus of tumour immunotherapy. In DC-vaccine trials, induction of tumour antigen-specific immunity is observed frequently and well-documented clinical responses have been reported. However, the overall response rate is less than 3%, therefore alternative strategies are being investigated. CD40-activated B cells (CD40-B) have been characterized previously as an interesting alternative because they present antigen efficiently and can be expanded by several logs from small amounts of peripheral blood. To determine the central technical challenges of cell-based vaccines we performed a single-patient analysis of 502 patients from DC-based tumour vaccine trials and identified at least three factors contributing to their limited efficiency: (1) lack of cell numbers; (2) lack of documented purity thus high contamination of bystander cells; and (3) lack of quality control and thus heterogeneous or unknown expression of important surface molecules such as major histocompatibility complex (MHC) and chemokine receptors. Based on these findings we re-evaluated the CD40-B approach in cancer patients. Here, we show that proliferation of B cells from cancer patients is equivalent to that observed in healthy donors. Purity is always > 90% after 2 weeks and remains stable for several weeks. They have comparable antigen-presenting capability determined phenotypically and by allogeneic mixed lymphocyte reaction. Expression of CCR7 and CD62L was detected in all samples and B cells migrated towards the relevant homing chemokines. Taken together, CD40-B cells from cancer patients can be expanded in virtually unlimited numbers at high purity and full function concerning antigen-presentation and migratory properties. [ABSTRACT FROM AUTHOR]

Imbalance of cytokine homeostasis is a prominent feature of both experimental and human systemic lupus erythematosus (SLE). Because interleukin (IL)-12 promotes interferon (IFN)-γ production leading to polarization of peripheral cells toward a T helper (Th) 1 phenotype, we investigated its role in lupus nephritis (LN). Soluble Th1 and Th2 cytokines were measured by enzyme-linked immunosorbent assay (ELISA) in sera and urines of SLE patients and controls. Th1/Th2 peripheral lymphocyte polarization was determined by flow cytometry. Glomerular accumulation of IL-12 was evaluated by immunohistochemistry, whereas urinary IL-12 was evaluated by ELISA. Higher serum IL-12 levels in SLE were associated with LN, whereas IL-4 was unrelated to the renal damage. Peripheral cells from LN patients showed a Th1 phenotype with a high IFN-γ expression that paralleled the severity of renal damage. IL-12 was present within glomerular mononuclear cells in classes IV and V LN, and its accumulation was correlated strongly with urinary levels. IL-12 overexpression in SLE may contribute to the development of LN. Both serum and urinary IL-12 elevation reflect its glomerular production and parallel Th1 polarization of peripheral T cells and high IFN-γ production. In SLE patients, IL-12 measurement may thus be predictive of the development of LN. [ABSTRACT FROM AUTHOR]

Coronary artery disease (CAD) is characterized by infiltration of monocyte derived cells in the intima of the vessel wall. We hypothesized that accumulation of these cells is caused partly by an altered monocyte transmigration process in CAD. To gain insight into this issue we applied the skin blister method that allows collection of in vivo transmigrated cells at sites of local inflammation. Nineteen patients with stable CAD and 19 matched controls were enrolled. Markers of inflammation and gradients of chemokines, as well as adhesion molecule expression and up-regulation capacity, were studied. The expression of inflammatory markers, such as C-reactive protein, interleukin (IL)-6, tumour necrosis factor-α and IL-10, was similar in patients and controls, indicating that patients were in a stable phase of the disease. Expression of adhesion molecules, CD11b and very late activation antigen-4, on peripheral monocytes did not differ between patients and controls. However, following in vivo transmigration, monocytes in patients with CAD had a significantly reduced expression and mobilization of CD11b. The effect on CD11b could not be reproduced by in vitro stimulation with blister fluid, representing a local inflammatory milieu, or in an in vitro system of transmigration. These findings point towards differences in monocyte CD11b expression and availability at an inflammatory site between patients with CAD and healthy controls. [ABSTRACT FROM AUTHOR]

Traditional wisdom has considered fibroblasts as contributing to the structural integrity of tissues rather than playing a dynamic role in physiological or pathological processes. It is only recently that they have been recognized as comprising diverse populations of cells exhibiting complex patterns of biosynthetic activity. They represent determinants that react to stimuli and help define tissue remodelling through the expression of molecules imposing constraints on their cellular neighbourhood. Moreover, fibroblasts can initiate the earliest molecular events leading to inflammatory responses. Thus they must now be viewed as active participants in tissue reactivity. In this short review, I will provide an overview of contemporary thought about the contribution of fibroblasts to the pathogenesis of autoimmune processes through their expression of, and responses to, mediators of inflammation and tissue remodelling. [ABSTRACT FROM AUTHOR]

We have shown previously that lgG2a anti-Thy-1 MoAb (ER4G) induces apoptosis of rat mesangial cells (GMC) in vitro. Since the classical complement pathway plays an essential role in Thy-1 nephritis, we analysed whether Clq, a subunit of the first component of complement, enhances the ER4Gmediated apoptosis of rat GMC. Two different subclasses of anti-Thy-l MoAb. ER4G (lgG2a) and ER14 (IgGl), were used. It was established that ER4G binds Clq efficiently, while ER14 reacts poorly with Clq. For the experiments of apoptosis. quiescent rat GMC were exposed for I h at 37°C to a fixed concentration of anti-Thy-1 MoAb and incubated further for 16 h at 37&degC in the presence or absence of Clq. GMC exposed to medium (M-GMC) followed by incubation of the cells with medium alone was used as controls. Apoptosis was assessed by morphological studies and quantitative analysis on FACS using FITC-annexin V (the annexin V methods) or bicolour FACS analysis using FITC-annexin V and propidium iodide (the annexin V/Pl method). With the annexin V method, M-GMC revealed 9 4 ± 14% apoptosis. Clq had only tnarginal effects on apoptosis of M-GMC. GMC exposed to ER4G (ER4G-GMC) and further incubated with medium in the absence of Clq resulted in 25.7 ± 5.7% apoptosis (P<0.01 relative to control). Incubation of ER4G-GMC together with 100 μg/ml of Clq significantly increased GMC-apoptosis up to 39.4 ± 4.9% (P<0.01 relative to ER4G-GMC incubated in the absence of Clq), This enhancing effect of Clq on apoptosis of ER4G-GMC was time- and dose-dependent. In contrast. Clq did not significantly alter the apoptosis of either GMC exposed to ER14 (ER14-GMC) or to F(ab')2-ER4G (F(ab') 2-ER4G-GMC). while ER14-GMC or F(ab') 2-ER4G-GMC incubated with medium resulted in significant apoptosis compared with control. These results were supported by morphological studies and bicolour FACS analyses in time course experiments using the annexin V/PI method. The effect of Clq is dependent on the presence of intact Clq-containing globular heads and does not occur with collagen-like fragments of Clq. Furthermore, incubation of ER4G-GMC with antimouse κ-chain antibodies also increased ER4G-mediated GMC-apoptosis. These results indicate for the first time that Clq enhances antibody-mediated apoptosis of rat GMC in vitro, presumably by its binding to ER4G and probably by additional cross-linking of Thy-1 on the surface of GMC. [ABSTRACT FROM AUTHOR]

In a previous study, we reported an increase in the number of immunoglobulin-secreting cells and the augmentation of antibody production (IgM and IgG3) against unrelated antigens (sheep erythrocytes or bovine serum albumin (BSA)) in mice infected with the fungus Paracoccidioides brasiliensis as well as in mice inoculated with its cell wall preparation (CW). The immunomodulatory effect of the live fungus and CW preparation was dose-dependent and mainly restricted to the i.p. inoculation simultaneously to the BSA challenge by the i.v. route. In the present study, we investigated the active component of CW preparation upon the phenotype and also the degree of activation of possible target peritoneal cells involved in those phenomena. An insoluble polysaccharide fraction (F1 fraction) mainly composed of β-glucan and chitin, and the purified β-glucan (BGPb) behaved as CW in the augmentation of early antibody production. The peritoneal mononuclear inflammatory cells induced by CW, F1 fraction and BGPb were highly positive to α-naphthyl esterase staining; released low H2O2; expressed high levels of MHC-Iad molecules and produced inflammatory cytokines such as tumour necrosis factor-alpha (TNF-α) and IL-6. Phenotypic analysis by flow cytometry and immunohistochemical techniques of the inflammatory cells responding to F1 fraction showed a prevalence of (CD11b/CD18, Mac-1)+ peritoneal macrophages. In addition, s.c. inoculation of F1 fraction resulted in the formation of nodular, localized and not progressive granulomatous lesions with an accumulation of (CD11b/C18)+ macrophages. Adoptive transferred Mac-1 macrophages to immunized syngeneic recipient mice were able to cause an increase in anti-BSA antibody production. These results suggest that inflammatory (CD11b/CD18)+ macrophages may be related to immunological disturbances, caused by cell wall components of P. brasiliensis. [ABSTRACT FROM AUTHOR]

Anti-endothelial and other cell membrane-reactive antibodies in scleroderma were characterized by immunoblotting sera with membrane and cytosol preparations of human umbilical vein endothelial cells (HUVEC). dermal fibroblasts and a T cell lymphoma HUT78. Antibodies reactive with HUVEC membranes were found in 17 of 20 patients with scleroderma (33 bands) in contrast to only two of 20 controls (two bands; P < 0.01) and three of 11 patients with myocardial infarction (four bands). Eleven of the 20 patients possessed antibodies that were specific for HUVEC membrane and did not cross-react with other cell lines. Analysis of patient subgroups showed that HUVEC membrane antibodies were present in nine of 11 patients with systemic sclerosis and in all nine with the CREST syndrome, and were HUVEC-specific in five and six of these cases, respectively. Although considerable heterogeneity was seen, antibodies to an 18-19-kD membrane epitope were found in 11 of the 20 patients but in none of the controls (P < 0.01). This antibody which reacted particularly with HUVEC (n = 9) and HUT78 membranes (n = 9) was associated with CREST syndrome rather than systemic sclerosis (9/9 versus 1 /11 ; P<0.01), and after elution was shown to possess anticentromere activity. In addition, antibodies reactive with both fibroblast (n = 11; 18 bands) and HUT78 membranes (n = 18; 42 bands) were detected and were specific for either fibroblast or HUT78 membranes in nine and 14 patients, respectively. There was no significant difference in the incidence of these fibroblasts and HUT78 membrane antibodies in the two patient subgroups. These findings support the concept that membranereactive antibodies, including anticentromeric antibodies, may play a central role in the pathogenesis of scleroderma, through their ability to react with endothelial cells. [ABSTRACT FROM AUTHOR]

The central highlands of Madagascar offer a unique opportunity to explore the malaria immune memory, as the last murderous epidemic in the study area occurred 8 years ago. Quantification of the circulating memory B lymphocytes reacting to Plasmodium falciparum was assessed among 14 Madagascans by using a limiting dilution assay, applied to the EL4 culture system, which leads to activation, proliferation and differentiation into antibody-secreting cells (ASC) of most peripheral B cells. This system allowed us to observe, without any malaria-specific restimulation, a geometric mean frequency of one anti-P. falciparum ASC among 2992 circulating B cells, except for one Madagascan who did not have any detectable ASC. A geometric mean frequency of one anti-P. falciparum ASC among 1403 was obtained for six malaria hyperimmune Cameroonians, but conversely, no anti-malaria ASC was detected in the blood of six malaria non-immune French control subjects. Anti-P. falciparum ASC frequencies and serum specific antibodies were strongly related. Our results indicate that anti-malaria ASC are still present in peripheral blood of Madagascan subjects, who have not been exposed to P. falciparum for several years. These responder B cells reflect the malaria B cell memory acquired during the last epidemic [ABSTRACT FROM AUTHOR]

T cells from patients with CVID have defects that may relate to the failure in vivo of B cell production of antibodies. Antigen-driven responses of T cells from CVID patients and normal subjects have been assessed by measuring DNA synthesis in vitro. Low density cells enriched for antigen-presenting dendritic cells were pulsed with purified protein derivative (PPD) and cultured with autologous T cells. Overall, T cells from CVID patients showed a significantly low mean response to PPD, although non-specific DNA synthesis induced in CVID T cells by IL-2 was within the normal range. However, mean PPD-specific T cell responses in CVID were not restored by IL-2 irrespective of the presence of monocytes. Depletion of CD8+ cells also failed to restore the mean PPD response of CVID CD4+ T cells. Limiting dilution analysis showed that in CVID there was a reduced frequency of antigen-specific cells within the T cell preparations. The mean frequency of the PPD-specific T cells in cultures from patients vaccinated with bacille Calmette Guérin (BCG) was reduced to 1 in 109000 T cells compared with 1 in 18600 T cells in BCG-vaccinated normal donors. These data show that the reduced PPD-specific response in CVID is due to a partial peripheral loss of antigen-specific cells. [ABSTRACT FROM AUTHOR]

We addressed the question of whether or not expression of human endogenous retroviruses (ERV), ERV3 and λ4 1, is related to the pathogenesis of rheumatoid arthritis(RA). In genomic Southern hybridization, there were no significant differences between RA patients and healthy volunteers with regard to frequencies of restriction fragment length polymorphism (RFLP) patterns, for either ERV3 or λ4.1. By Northern blot analysis using fresh synovial tissues, cultured synovial cells, and peripheral blood mononuclear cells (PBMC) from patients with RA, we noted two molecular species of ERV3 mRNAs of 3.5 kb and 9.0 kb sizes, and one single molecular species of λ4-1 mRNAs of 4.2 kb size. The expression was detected not only in RA patients but also in synovial cells from osteoarthritis (OA) as a non-RA control and PBMC from healthy volunteers, and was not related to RA activities or treatments. Although ERV3 and λ4-1 expression may not be directly associated with the pathogenic pathway of RA. the possibility exists that human ERV may have a causative role in autoimmune diseases, including RA. We also examined the effect of cytokines on the transcriptional regulation of ERV3. Although the level of ERV3 expression in cultured synovial cells did not change with IL-1β treatment, the level for cultured proximal tubular epithelial cells (hKEC) was up-regulated. [ABSTRACT FROM AUTHOR]

Natural killer (NK) activity, detected by the lysis of Yac-1 target cells, was examined in splenic and mesenteric lymph node (MLN) cells throughout the course of infection with Eimeria vermiformis in BALB/c and C57BI/6 (B6) mice. These strains are, respectively, relatively resistant and susceptible lo primary infections, which render them equally, and completely, resistant to challenge. Resting levels of NK activity were higher In B6 than in BALB/c, and B6 responded earlier in the course of infection than BALB/c, but splenic peak values were higher in BALB/c; the pattern of response in MLN cells was similar in both strains, but the peak was higher in BALB/c. At the lime (7 days p.i.) of peak NK response in BALB/c mice there was, depending upon the choice of NK-resistant/ lymphokine-activated killer (LAK)-sensitive target cells, either little (P388D1), or no (P815) splenic LAK activity. Challenge of immunized BALB/c mice did not evoke a detectable NK response. Although the higher NK activity in BALB/c mice correlated with greater control of primary infection, depletion of NK activity (demonstrated in splenic cells) in vivo by treatment with anti-asialo GM1 antibodies did not greatly affect the course of infection. Furthermore, this treatment did not augment the exacerbation of infection produced by treatment with antiinterferon- gamma (IFN-γ) MoAb, indicating that, at least in this system. NK cells are not a fundamentally important source of this controlling cytokine of eimerian infections. The results suggest that NK cells may not greatly influence the outcome of coccidial infections. [ABSTRACT FROM AUTHOR]

The TCR repertoire of human CD8+ peripheral blood lymphocytes has been determined using MoAbs to the Vβ32, 3,5.1,5.2/5.3,6.7,8, 12 and 19(17) Vβ gene families. The CD8 T cell repertoire for Vβ2 and Vβ3 is shown to be skewed, with an excess of individuals having higher values than are consistent with a normal distribution. A significant majority of these individuals are over the age of 40. High values of Vβ CD8+ cells were found for each Vβ family studied except for 6.7a. Individual high values are stable for at least 12 months. In addition, the total percentage of CD4 and CD8 cells reacting with this panel of reagents was determined. There is a significant excess of Vβ CD4+ cells (33%) over CD8+ Vβ+ cells (21.9%). Thus the human CD8 Vβ repertoire differs from the human CD4 repertoire in a number of important ways. [ABSTRACT FROM AUTHOR]

In order to discover some biological markers of acute graft-versus-host disease (aGVHD), we have studied the percentage of peripheral monocytes and T lymphocytes bearing HLA-DR and HLA-DQ class II molecules. This study included 25 allogencic BMT in children either with (n = 10) or without (n = 15) aGVHD. Within 2 months after transplantation, a higher percentage of DQ+ and DR+ monocytes and of DQ+ T lymphocytes was observed in patients without aGVHD compared with patients with aGVHD, The most discriminating marker was the strong increase in the percentage of DQ+ monocytes in patients without aGVHD (P = 0 001). In a sequential study, we observed a low percentage of DQ+ and DR+ peripheral blood mononuclear cells (PBMC) as long as the clinical manifestations of aGVHD continued. We speculate if the modulation of DQ and DR molecules on PBMC after BMT is a consequence of the action of some lymphokines, and if it plays a role in the regulation of the acute GVH reaction. We conclude that MHC class 11 molecules on peripheral mononuclear cells may be reliable biological markers for the diagnosis of aGVHD. [ABSTRACT FROM AUTHOR]

Cytokines are important mediators involved in the development of effector cells and in the regulation of immune responses. The gene expression of these mediators in T cell subset has yet to be fully elucidated. Using sensitive reverse transcription-polymerase chain reaction (RT-PCR), the kinetics of cytokine gene expression in human CD4+ and CD8+ T cells were examined. CD4+ T cells were more readily activated by phorbol myristate acetate (PMA) and phytohaemagglutinin (PHA) than CD8+ T cells in terms of the IL-2 receptor (IL-2R) mRNA expression. Quantitative differences in cytokine gene expression between CD4+ and CD8+ T cells were confirmed and higher levels of cytokine mRNAs were induced in CD4+ than in CD8+ T cells. Early induction of IL-2 mRNA was observed in both T cell subsets. The demonstration of different kinetics of cytokine gene expression illustrates one of the examples of the complexity of immunoregulation. The differential response of cytokine gene expression in different T cell subsets should be taken into consideration when clinical studies in cytokine production by peripheral blood mononuclear cells are interpreted. [ABSTRACT FROM AUTHOR]

A characteristic feature associated with HIV-1 infection of the human host is a chronic decline in circulating CD4+ T helper/inducer cell numbers. Impaired cell-mediated immune functions usually occur in parallel with the decline in CD4+ T cells. Activated CD4+ T helper cells are a major source of endogenous IL-2 which is required for the immunoregulation of both antigen-specific B cells and CD8+ T cells. HIV-specific T cell proliferative responses are said to be weak and inconsistent, even during the asymptomatic phase of disease. We thus wished to determine how exogenous IL-2 affected HIV-specific T cell proliferation at different stages of the disease. Our cohort of 81 included both asymptomatic and symptomatic HIV-infected patients as well as uninfected normal donors. Proliferative responses of peripheral blood mononuclear cells (PBMC) that were elicited during culture with an immunodominant gp41-derived synthetic peptide, gp41(8), and which were known to be CD8+ cell-associated in asymptomatics only, were used to analyse the effects of exogenous IL-2, IL-2 had three main effects on HIV-specific proliferation, namely (i) an additive effect, (ii) a synergistic effect, and (iii) an induced effect. More specifically, low dose exogenous IL-2 frequently augmented lymphoproliferation in both asymptomatic and symptomatic gp41(8) responders. In most symptomatics, however, who were predominantly gp41(8) non-responders. exogenous IL-2 induced lymphoproliferation. Flow eytometric analyses using dual immunofluorescence were used to analyse the T cell subset distribution of proliferating PBMC cultures. During culture with gp41(8), both CD4+ and CD8+ T cell numbers increased. However, after the addition of exogenous IL-2 to gp41(8)-containing cultures, CD8+ cell-associated lymphoproliferative responses were preferentially augmented. These results suggest that in symptomatics there is an inadequate supply of endogenous IL-2 to help maintain the strong and effective CD8+ cell-associated anti-viral immunity, and an exogenous supply of IL-2 may be required. [ABSTRACT FROM AUTHOR]

Antibody penetration of viable cells and interaction with intracellular antigens may have major consequences for immunopathological processes in connective tissue diseases. We have reported previously that antibody can penetrate viable human lymphocytes. To assess further the role of antinuclear antibodies in this process, peripheral blood lymphocytes (PBMC) were incubated with FITC-conjugated IgG fractions from sera containing anti-RNP (anti-RNP IgG), Ro(SS-A), La(SS-B) and dsDNA antibodies and control sera for 24 h. Using crystal violet to quench cell surface staining, intracellular fluorescence of viable lymphocytes was quantified on the flow cytometer. It was noted that anti-RNP IgG entered 46.4 ± 72% of lymphocytes which was significantly higher than anti-Ro(SS-A) (29.9 ± 4.1%, P < 0.05), La(SS-B) (22.0 ± 7.5%, P < 0.01) IgG and control IgG (28.8 ± 2.1%, P < 0.05) and not statistically different from anti-dsDNA IgG (32.6 ± 14.3%). Inhibition experiments showed that the increased number of cells penetrated by anti-RNP IgG was a specific process. Time-course studies showed that anti-RNP IgG entry into cells was different from pooled control IgG. With anti-RNP IgG, positive-staining lymphocytes gradually increased in number from 12 to 24 h incubation, whilst with pooled control IgG, the peak was reached within 5 min. Dual staining experiments suggested that whereas both anti-RNP IgG and pooled control IgG entered B and NK cells, anti- RNP IgG also entered T cells. Using IgG F(ab')2 and Fc fragments from either anti-RNP IgG or pooled control IgG to compete with their FITC-conjugated counterparts indicated that the entry of anti-RNP IgG into viable cells appeared to involve both F(ab')2 and Fc fragments, and pooled control IgG depended exclusively on the Fc portion of IgG. Further investigation by incubating anti-RNP IgG with 35S-methionine-labelled monocyte-depleted PBMC (MD-PBMC) suggested that anti-RNP IgG might react with the corresponding antigens either on the cell surface or within the cytoplasm. [ABSTRACT FROM AUTHOR]

To evaluate the proportion of helper cell subsets we studied 18 children with atopic dermatitis, 30 patients with asthma, 27 healthy age-matched controls aged 1 to 17 years and 11 atopic controls without symptoms related to atopy, aged 9-22 years. Lymphocytes were isolated from heparinized peripheral blood and the proportion of CD4+CD29+ and CD4+CD45R+ cells was determined by double-labelling immunofluorescence. Children with atopic dermatitis yielded a significantly (P < 0.01) higher proportion of CD4+CD45R+ (median 75%) cells compared with normal controls (median 66.6%), whereas the proportion of CD4+CD29+ cells was significantly (P < 0.001) lower in patients with atopic dermatitis (median 20.4 versus 29.6%). Interestingly, the percentage of CD4+CD45R+ cells shows an age-dependent decline (r = -0.67, P < 0.01) in the control group., which is not found in the patient group. [ABSTRACT FROM AUTHOR]

Enhanced natural killer (NK) activity and normal lymphocyte antibody-dependent cellular cytotoxicity (ADCC) were observed in 16 patients with a diagnosis of progressive systemic sclerosis (PSS). Higher NK activity levels were observed against NK-sensitive K562 target cells. while the NK- resistant P815. Daudi and Raji cell lines were not lysed. Cytofluorimetric studies and morphological analysis of peripheral blood lymphocytes (PBL) showed an increased number of CDI6 positive cells and large granular lymphocytes (LGL)1 indicating that the enhancement observed was probably attributable to an increase in the number of circulating NK cells. [ABSTRACT FROM AUTHOR]

Macrophages from peripheral blood of leprosy patients, both multi-bacillary and paucibacillary are unable to kill phagocytosed Mycobacterium leprae due to their inability to produce superoxide (O2-) and hydroxyl radicals (OH·). The macrophages from healthy individuals are able to kill M. leprae along with release of O2- and OH· radicals. The deficiency in the macrophages of both types of leprosy patients is removed by activation of these cells when exposed to a culture supernatant obtained after stimulation of peripheral blood mononuclear cells from the same patients with delipidified cell components of M. leprae which are most likely cell wall proteins. The activation of macrophages also leads to recognition of whole live M. leprae as an antigen by cells from lepromatous patients. This activation of the phagocytes by delipidified cell components is blocked by cyclosporin A, indicating the possible role of several steps involved in immune activation of cells. The observations thus indicate the significant ability of delipidified cell components to eliminate the deficiencies in the macrophages from leprosy patients and restore them to behave like the cells from healthy individuals. Considering all these, it is suggested that delipidified cell components could be potential modulators, and are probably capable of functioning as a vaccine for leprosy. [ABSTRACT FROM AUTHOR]

The cellular control of antibody affinity maturation has been studied in mice genetically selected for their failure to demonstrate an increase in affinity following immunization (low-affinity N/M mice). Depletion of CD8+ cells In low N/M mice by thymectomy and/or anti-CD8 antibody treatment resulted in these animals acquiring the ability to mount an anti-DNP response of progressively increasing affinity. This indicates that CD8+ cells play an important regulatory role in the cellular interactions underlying the process of affinity maturation. In addition, evidence is presented which suggests that the route of immunization may also be critical in determining the affinity of antibody produced. [ABSTRACT FROM AUTHOR]

To investigate the involvement of tumour necrosis factor (TNF) in human malaria, we studied TNF production in patients infected with Plasmodium falciparum, and in co-cultures of human mononuclear cells and malaria parasites in vitro. In the examined sample, plasma TNF levels of over 39 pg/ml were detected in the plasma of 59% of Gambian children with acute malaria, 17% of convalescents, 9% of children with mild infections other than malaria, and 7% of healthy Gambian adults. Mononuclear cells of acute malaria patients, when stimulated with endotoxin in vitro, secreted twice as much TNF as did those of convalescent individuals, and three times that of healthy adult controls. Erythrocytic cultures of P. faiciparum stimulated increased TNF secretion by mononuclear cells from uninfected individuals, and a sharp rise in the rate of secretion occurred shortly after schizont rupture. We suggest that malaria fever is mediated, at least in part, through paroxysmal TNF release associated with schizont rupture. [ABSTRACT FROM AUTHOR]

We have assessed the ability of HIV to infect cultures of peripheral blood lymphocytes derived from different healthy donors, varying in age between 20 and 76. The results indicate that cells from all of these people can be infected, although the percentage of infected cells varied from case to case. A similar variation was observed when attempts were made to infect cells from the same donor on more than one occasion. In most cases, infection by HIV led to persistence of an activated cell slate, as indicated by the presence of Tac Ag or IL-2 receptor, at the cell surface. Co-incubation of HIV-infected lymphocytes with uninfected cells did not affect the ability of the latter either to respond to phytohaemagglutinin (PHA) or to express Tac Ag. [ABSTRACT FROM AUTHOR]

The aim of the present study was to determine the interval after orthotopic liver transplant during which the &alpha1-AT phenotype in the serum changes. Eleven patients could be evaluated because the donor and recipient had different a1-AT phenotypes. The results showed that within 1 to 3 days of the transplant donor &alpha1-AT is already present in the serum of the recipient, and subsequently the transplanted liver continued to synthesize &alpha1- AT of the donor phenotype. The result confirmed that liver parenchymal cells are the main site of &alpha1-AT synthesis. [ABSTRACT FROM AUTHOR]

Epidermal changes, Ia expression on keratinocytes, Langerhans cell hyperplasia and lymphocyte infiltration were sought in skin lesions of leprosy: 15 borderline tuberculoid (BT), six borderline lepromatous (BL), 17 lepromatous (LL), 13 erythema nodosum leprosum (ENL), six Lucio reactions and nine reversal reactions. All three changes were well developed in BT and reversal reactions. ENL showed well developed keratinocyte Ia and Langerhans cell hyperplasia, but little lymphocytic infiltration. LL and Lucio tissues had some Langerhans cell hyperplasia but little or no keratinocyte Ia or lymphocytic infiltration. BL tissues were so diverse as to suggest two distinct subgroups. These findings are consistent with the hypothesis that keratinocyte la expression is an immunohistological sign of a cell-mediated immune (CMI) response. However, the Ia keratinocyte expression found in BL and ENL tissues appears contrary to the undifferentiated macrophages and numerous bacilli found in the lesions. Thus, if a sign of CMI. keratinocyte la expression is not a measure of the effectiveness of the response. [ABSTRACT FROM AUTHOR]

Pokeweed mitogen (PWM)-induced B-bell activation was entirely abrogated by pre-treating peripheral mononuclear cells (PBM) with T4 (anti-T-helper-inducer subset) or T11 (anti-sheep erythrocyte receptor, ie. Anti-pan-T-cell) monoclonal antibody plus complement. Immunoglobulin secretion was restored in T11- but not T4- cultures by adding the culture supernatant from PWM-stimulated PBM (T-replacing factor, TRF). Since T8+ (T-suppressor-cytotoxic subset) cells were present in high concentrations in T4- but absent from T11- cultures, it appeared that these cells could inhibit B-cell activation by PWM plus TRF and that suppression could occur in the absence of T4+ cells. Incubation of TRF with purified, unstimulated T8+ cells prior to addition to T11- cultures abrogated subsequent PWM-induced B-cell activation, whereas T8- PBM had no effect on TRF. T8+ cells did not secrete suppressor factors during incubation with TRF. Absorption of one or more of the factors required for B-cell growth and differentiation by T8+ cells appears to be an important suppressor mechanism operating in the PWM system. [ABSTRACT FROM AUTHOR]

A complement fixing, non-organ specific IgG autoantibody is described in 29 patients. The autoantibody gives a highly characteristic, granular staining of liver cells, proximal kidney tubules and stomach surface epithelium. By studies with various subcellular fractions from rat liver, employing two different techniques (quantitative complement fixation, and absorption combined with indirect immunofluorescence) the autoantibody was shown to react with a peroxisomal antigen. No convincing clinical correlations were found. [ABSTRACT FROM AUTHOR]

Monocytes and macrophages synthesize thromboplastin when induced by a number of compounds. Our experiments show that cyclosporine A (CyA) enhances the synthesis of procoagulant activity in monocytes and in whole mononuclear cells (MNC) about two-fold when phytohaemagglutinin (PHA) is the stimulant. The enhancement is inhibited by actinomycin D and cycloheximide. CyA alone had no effect, but in the presence of PHA or phorbol ester CyA induces or enhances the synthesis of a vitamin K-dependent procoagulant in the MNC cultures. This procoagulant acts synergistically with thromboplastin synthesized in the same cultures. [ABSTRACT FROM AUTHOR]

We report a study on immunoregulation of in vitro antibody to hepatitis B surface antigen (anti-HBs) synthesis induced by pokeweed mitogen (PWM) from peripheral blood mononuclear cells (PBMC) in chronic hepatitis B surface antigen (HBsAg) carriers and in 'high responders' (anti-HBs RIA ratio &ges; 20 in scrum), recently boosted with anti-hepatitis B vaccine. Anti-HBs was detected in 11 days PBMC supernatants (SN) from 24 out of 36 'high responders', but in none from 31 chronic HBsAg carriers, despite detectable amounts of polyclonal IgG and antibody to hepatitis B core antigen (anti-HBc) were produced. The lack of anti-HBs production by chronic HBsAg carriers did not seem to be determined by suppressor influences because T lymphocytes from the majority of chronic HBsAg carriers, co-cultured with 'high responders' PBMC did not suppress anti-HBs production, Co-cultures between HBsAg carriers T4 positive (helper/inducer) cells and allogenic 'high responder' non-T cells produced anti-HBs antibody, indicating that HBsAg carrier T cells are not deficient in this allogenic helper function under PWM stimulation. Allogenic cocultures between HBsAg carrier non-T cells and 'high responder' T4 positive cells failed in anti-HBs production: a specific B lymphocyte defect might be involved in the lacking anti-HBs synthesis in chronic HBV patients. Antigen-induced specific anti-HBs synthesis experiments indicate that B cells themselves seem to be the target for HBsAg-induced suppression of anti-HBs antibody response. [ABSTRACT FROM AUTHOR]

Secretors IgA antibody responses such as those directed against respiratory and enteric pathogens, may be impaired in protein-calorie malnutrition. In previous studies using a rat model of the mucosal immune response to cholera toxin, as little as 2 weeks of severe protein deprivation markedly impaired mucosal anti-toxin production. The present studies examined the effect of protein deprivation on lymphocyte populations which adoptively transfer either priming or suppression of a mucosal anti-toxin response from malnourished donor rats to syngeneic well nourished recipients. Either 2 or 8 weeks of protein deprivation severely impaired the development of thoracic duct lymphocytes which could transfer priming or suppression alter intraduodenal priming, and impaired splenic suppressor cell development after sc, priming. The abrogation of suppression by protein deprivation was dependent on the dose eke. antigen used to induce suppression. Refeeding rats after two months of protein deprivation led to recovery of both priming cell and suppressor cell function. Severe protein deprivation induces a reversible defect in both priming and suppressor cell populations: the net effect is an impaired mucosal immune response. [ABSTRACT FROM AUTHOR]

Oral administration of cyclosporin A (Cy A). an immunosuppressive agent, prolonged the life span of female NZB/NZW (F1) hybrid mice (NZB/W). The most prominent feature of this study was the reduction of glomerular proliferation proteinurea. and delay of renal failure. Protection from renal damage. in treated mice, occurred despite similar degrees of perivascular cellular infiltration in the kidney and other organs, and glomerular deposition of immunoglobulin and complement. Treatment did not influence the hypergammaglobulinaemia. high levels of circulating immune complexes and later development of autoimmune haemolytic anaemia typically associated with this murine disease. The levels of antibodies to double stranded DNA (dsDNA). an important disease marker, and the response to sheep red blood cells were reduced in the Cy A treated mice, in contrast with the untreated mice. Levels of rheumatoid factors were increased in Cy A treated mice, when compared with untreated mice, and this could play a role in prolongation of life associated with protection from glomerular damage, although it was considered that inhibitory effects on T cell function were a more likely mechanism. [ABSTRACT FROM AUTHOR]

Normobaric O2 exposure decreased spleen cell (SC) response to T cell mitogen Con A. ³H-TdR incorporation of SC from O2 exposed mice (O2SC) compared to those of control mice (Air SC) decreased significantly after 72 and 87 h O2 exposure. The dose response kinetics to Con A were identical in O2SC or Air SC. Increasing SC number did not restore the response to Con A and the depressed hyperoxic effect was not related to suppressor cells in the spleen of O2 exposed mice. Response of O2SC to Con A was restored by the thiol compound 2-niercaptoethanol (2-ME). and the degree of restoration by 2-ME. was inversely proportional to the depressed response. Addition of intact peritoneal cells (PC) induced restoration within the same range as 2-ME. Restoration of the mitogenic response by 2-ME involved antioxidant properties and suggested that macrophages were functionally injured by O2 exposure. In cases where mitogen response was highly depressed, restoration was only partial; in these conditions in vivo O2 injury probably involved both macrophages and splenic T cells. The mechanisms of O2 toxicity have been discussed in terms of free radical generation under hyperoxic conditions. [ABSTRACT FROM AUTHOR]

Murine I-J gene products have been found in T suppressor cells (SC) and factors, macrophages and contrasuppressor cells (CSC). However, a human counterpart of the murine I-J has not been reported. As there is strong evidence that some murine anti-la antisera cross-react with human la antigens, the possibility was tested that mouse anti-I-J antibodies might cross-react with corresponding human class II determinants. Indeed, this revealed that three anti-I-J monoclonal antibodies (MoAb) and two antisera tested react with human mononuclear cells and that a significantly greater proportion of T8+ than T4+ cells or monocytes (Mo) react with the I-J antibodies. This was corroborated by autoradiography with significant inhibition of 125I-SA (streptococcal antigen) binding to T8+ cells but not to Mo by the MoAb or antisera to murine I-J. Functional reconstitution experiments of T4+ helper cells with the SA binding and presenting T8+ Vicia villosa adherent cells (VV-AC) and assessment of specific antibody forming cells to SA suggest that the antigen presenting function of this T8+ subset can be significantly inhibited by killing with the MoAb to I-J and complement. Furthermore, the subset of T8+ VV-AC also functions as CSC, for killing with MoAb to I-J and complement significantly inhibited the contrasuppressor function. This is consistent with the presence of I-J gene products in murine CSC. However, similar treatment of T8+ VV-NAC (non-adherent cells) or monocytes (Mo) failed to affect the suppressor or accessory helper function of these cells, respectively. Phenotypic characterization, inhibition of 125I-SA binding and reconstitution experiments for helper and suppressor functions, suggest that a subset of T8+ antigen binding, presenting and CSC may express determinants cross-reacting with murine I-J molecules. [ABSTRACT FROM AUTHOR]

Helminth parasites induce production of high levels of IgE antibodies but the immunoregulatory mechanisms determining this IgE biosynthesis are poorly understood. To investigate these mechanisms, peripheral blood mononuclear cells were obtained from six normal controls, six atopic patients and eight patients with parasitic helminth infections (three with schistosomiasis, two with loiasis. three with onchocerciasis). Cells were cultured at 1 × 106 cells/ml for 8 days in the presence of media alone or media supplemented with pokeweed mitogen (PWM) or cycloheximide; the supernatant fluids from these cultures were then assayed quantitatively for total and parasite specific IgE and IgG using an avidin-biotin amplified (for IgE) or standard (for IgG) microelisa assay. The geometric mean spontaneous IgE production was markedly elevated in peripheral blood mononuclear cells from parasitized individuals (2,487 pg/ml) when compared to those from atopics (358 pg/ml) or normals (152 pg/ml). Spontaneous IgG synthesis was equivalent in all three groups (range 140-420 ng/ml). PWM did not induce IgE production in any group and in the parasitized group even caused significant suppression of total IgE synthesis. Antigen specific antibody production (both IgE and IgG) paralleled total immunoglobulin synthesis. These findings demonstrate for the first time spontaneously enhanced IgE production in vitro in patients with helminth infections and provide a model system for studying the suppressive and regulatory mechanisms controlling IgE secretion. [ABSTRACT FROM AUTHOR]

Defects in cellular communication are fundamental to the development of autoimmune disease. Modulation of immunoregulatory events can be mediated by cellular expression of Ia antigens. We have analysed, by flow cytometry, the !a antigenic levels on cells from mice expressing the Ipr gene and their congenic counterparts. Surface la expression is dramatically increased on bone marrow, thymus, lymph node and spleen cells from for mice even prior to characteristic lymph node and spleen enlargement. In addition, IL-2 production abnormalities occur in the low density Lyt 1 subset of Thy 1.2 positive cells of normal mice which may be the counterpart of the majority cell type of lpr lymphocytes. Treatment of lpr mice with low dose whole body irradiation (300 rad) decreases lymphadenopathy, autoantibodies. proteinuria and the resident la positive cell population while increasing survival. We conclude that lymphoid alterations induced by irradiation reflect a recovery of immunological control associated with suppression of autoimmune manifestations. [ABSTRACT FROM AUTHOR]

The reverse haemolytic plaque assay (RHPA) was used to enumerate circulating and bone marrow (BM) immunoglobulin secreting cells (ISC) in patients with multiple myeloma (MM) and monoclonal gammopathy of undetermined significance (MGUS), as well as in normal controls. Significantly greater quantities of plaque forming cells (PFC) secreting the same isotype of the serum M component were detected in the peripheral blood of MM patients than in the blood of MGUS patients or normal subjects. Comparative analysis of the numbers of monoclonal PFC in both peripheral blood (PB) and BM at diagnosis usually showed a higher number as well as more precocious chemotherapy-induced variations of ISC in the BM compartment than in the PB. Although large individual variations were observed during follow-up studies of MM patients, persistently increased or decreased levels of monoclonal PFC were often found to accompany (and sometimes to precede by months) the phases of relapse or remission, respectively. Similarly to IgG-MGUS patients, a distorted ratio of IgGκ to IgGλ secreting cells was consistently detected in patients with smouldering MM, although the total number (IgGκ plus IgGλ) of ISC appeared within normal limits. It is suggested that, in addition to other clinical and laboratory criteria, the RHPA may be of value in the diagnosis and follow-up of patients with monoclonal gammopathies. [ABSTRACT FROM AUTHOR]

The ability of muramyl dipeptide (MDP), its adjuvant inactive stereoisomer, MDP(D-D), and the non-pyrogenic, adjuvant active analogue, MDP-butyl ester (MDP-BE), to induce in vitro proliferation and/or polyclonal activation (PA) of peripheral blood mononuclear cells (PBMNC) from normal volunteers, was studied. MDP, as well as its two analogues, were incapable of inducing 3H-thymidine uptake or immunoglobulin synthesis in PBMNC cultures from the majority of the individuals tested. However, these muramyl peptides were capable of regulating the in vitro proliferative responses of some individuals to concanavalin A and to soluble antigens of Candida albicans. At the same time, enhancement of the pokeweed mitogen-induced IgA and IgM but not IgG PA was observed with MDP, its adjuvant active analogue MDP-BE, but not with the adjuvant inactive stereoisomer MDP(D-D). Results are discussed with relation to a possible genetic restriction of the responsiveness to MDP. [ABSTRACT FROM AUTHOR]

Splenic in vitro immune responses from C57B1/6 mice have been evaluated after intratracheal (i.t.) or intravenous (i.v.) inoculation with live Histoplasma capsulatum yeast cells. Significant (P < 0.005) numbers of cells reactive to heat killed H. capsulatum (HK-Hc) were present I week after i.t. inoculation with 5 × 105 viable yeast cells. In contrast, blastogenic responses to HK-Hc were not detected until 3 weeks after i.v. H. capsulatum inoculation. Examination of non-specific immunity, i.e. mixed lymphocyte responses to alloantigens and antibody formation to sheep erythrocytes, revealed a significant (P <0.005) and transient depression of these responses I week following i.t. H. capsulatum inoculation. The non-specific decreases associated with early (1 week) i.t. infection were not mediated by suppressor cells but were related to the number of viable yeast administered. [ABSTRACT FROM AUTHOR]

Human peripheral blood mononuclear cells (PBMC) were treated with a panel of monoclonal antibodies (MoAbs) for the demonstration of membrane antigens at the ultrastructural level. The bound MoAbs were linked by rabbit anti-mouse IgG to a peroxidase anti-peroxidase (PAP) complex composed of monoclonal mouse anti-peroxidase antibodies and horse radish peroxidase. This labelling method with a three step incubation procedure resulted in clear demonstration of the membrane antigens. Moreover, the use of the PAP complex as marker permitted the recognition of monocytes not only by morphology but also by their endogenous peroxidase pattern. In addition, it was observed that the MoAbs used, supposedly specific for T lymphocytes, reacted to a certain degree with monocytes. [ABSTRACT FROM AUTHOR]

Suppressor cell activity has been demonstrated in the peripheral blood of patients with leprosy. Cells bearing the suppressor/cytotoxic phenotype have been enumerated in both peripheral blood and tissues, and microanatomical differences in tissue distribution have been observed. This first generation of studies has been characterized by considerable disagreement, a not unusual circumstance in the study of leprosy. In the case of blood suppressor cell activity, there appears to be no doubt as to its existence, but much uncertainty regarding its distribution. Concerning peripheral blood phenotypic suppressor cells, the observed differences in lepromatous and ENL patients may well reflect differences in methods used. Concerning phenotypic suppressor cells in tissue, there is no agreement as to their numbers or microanatomical distribution across the spectrum of leprosy or in its reaction states. Although these observational differences make firm conclusions impossible, this first generation of studies has provided new ways of considering old problems. For example, lepromin unresponsiveness might be a consequence of active cellular suppression. Differences in the numbers (or percentages) of the suppressor phenotype in blood or tissues of lepromatous patients with or without ENL reopens the door to the possibility of cell-mediated immune mechanisms in the pathogenesis of ENL. The identification of defective suppressor cells as important in the pathogenesis of hypergammaglobulinaemia is of interest in and of itself, but also gives rise to the possibility that other kinds of phenomena may be a consequence of defective or effete suppressor mechanisms. The observation of microanatomical differences in the distribution of the suppressor phenotype in tuberculoid and lepromatous leprosy indicates that effective or ineffective immunity might be a sequela of particular interactions between the suppressor/cytotoxic and helper/inducer phenotypes, and that these interactions merit further study. These new perspectives may be subject to experimental testing by the next generation of studies, which will surely include the techniques of clonal expansion and limiting dilution, as well as the study of interleukins 1 and 2. [ABSTRACT FROM AUTHOR]

0KT4+ ( helper/inducer) and OKT8 (T cytotoxic/suppressor) subsets were depleted from peripheral blood lymphocytes (PBL) by complement-mediated lysis and residual cells examined for responsiveness to pokeweed mitogen (PWM) using a protein A haemolytic plaque assay for immunoglobulin secreting B cells. It was shown that: (I) three cycles of cell killing were required to totally abolish T helper function; (2) OKT4 PBL did not respond to PWM. but in a co-culture system, an equal number of unfractionated normal PBL could entirely reconstitute responsiveness of the residual B cells: (3)OKT8- PBL gave enhanced numbers of PWM-induced plaque forming cells (PFC); (4) addition of 4μg/ml concanavalin A (con A) to PWM stimulated OKT8" PBL failed lo suppress PFC generation, but suppression was induced by 12.5 and 25 μg/ml con A and (5) kinetics of PWM-induced PFC development were similar in the presence or absence of OKT8&plus; cells. [ABSTRACT FROM AUTHOR]