In vitro activation of T lymphocytes from human immunodeficiency virus (HIV)-seropositive blood donors. I. Soluble interleukin 2 receptor (IL2R) production parallels cellular IL2R expression and DNA synthesis

We investigated the relationship of soluble interleukin 2 receptor (sIL2R) production to cellular IL2R expression and DNA synthesis by mitogen-stimulated mononuclear cells from blood donors seropositive for human immunodeficiency virus (HIV). SIL2R was measured using an enzyme-linked immunosorbent assay which employed 2 anti-IL2R monoclonal antibodies recognizing distinct IL2R epitopes. Decreased phytohemagglutinin-induced DNA synthesis and cellular IL2R expression were accompanied by decreased levels of sIL2R in cell culture supernatants. Similar findings were observed for pokeweed mitogen-induced responses. There was no detectable spontaneous secretion of sIL2R into culture supernatants by unstimulated mononuclear cells from either HIV-seropositive or control seronegative donors. These findings indicate that thein vitro T-cell activation defects which characterize HIV infection include decreased sIL2R production, as well as decreased cellular IL2R expression and DNA synthesis. Further, they show that assessment of supernatant sIL2R levels can be used as a valid, reliable assay for T-cell activation.     

Expression of prorenin receptor in renal biopsies from patients with IgA nephropathy

Prorenin receptor (PRR) has been implicated in the onset and progression of various renal diseases, though its possible association with immunoglobulin A (IgA) nephropathy remains unclear. In the present study, we tried to clarify expression and pathophysiological significance of PRR in IgA nephropathy. We immunohistochemically assessed PRR levels in renal biopsy specimens from 48 patients with IgA nephropathy and evaluated its relevance to the clinical and pathological features of the disease. PRR was detected mainly in renal tubular cells, which was confirmed at the subcellular level using immunoelectron microscopy. The PRR-positive area (%PRR area) correlated with daily urinary protein, which is known to reflect disease severity (r=0.286, P=0.049). PRR levels were weaker in tubular cells bordering areas of severe interstitial fibrosis, where α-smooth muscle actin-positive myofibroblasts were present. We also used immunohistochemical detection of microtubule-associated protein-1 light chain 3 (LC3) and electron microscopy to assess autophagy, a cytoprotective mechanism downstream of PRR. We noted an apparent coincidence between autophagy activation in tubular cells and PRR expression in the same cells. Taken together, our findings suggest that renal expression of PRR in IgA nephropathy may be a compensatory response slowing disease progression by preventing tubular cell death and subsequent fibrosis through activation of cytoprotective autophagic machinery. Further studies using different type of kidney diseases could draw conclusion if the present finding is a generalized observation beyond IgA nephropathy.     

IgA肾病进展中MMP-2、TIMP-2与VEGF的表达变化

目的 探索在IgA肾病进展过程中MMP-2、TIMP-2与VEGF的表达变化、相互关系及其对逐渐进展的肾纤维化的影响.方法 收集60例确诊为IgA肾病的肾穿刺活检标本,将其分为5级,随机选取10例同期的肾小球微小病变作为对照组.利用免疫组化技术和图像分析技术检测病例组与对照组中MMP-2、TIMP-2、VEGF的表达.结果 随着IgA肾病进展,MMP-2和VEGF表达均在早期出现表达增强,随病变发展逐渐下降,TIMP-2表达强度则逐渐增加,MMP-2/TIMP-2的比值亦在短暂上升后出现下降.MMP-2与TIMP-2呈负相关关系,与VEGF呈正相关关系.结论 MMP-2/TIMP-2系统及VEGF的表达变化对于IgA肾病的进展具有重要影响,MMP-2/TIMP-2自然平衡的破坏对于肾纤维化过程具有关键性作用.     

Antibodies to polyclonal IgA,IgA1, and IgA2 and isotype-specific immune complexes in IgA nephropathy

The concentrations of serum IgG and IgM antibodies to polyclonal IgA (IgA_p), IgA₁, and IgA₂ were determined by enzyme immunoassay in 31 patients with IgA nephropathy and 30 healthy controls. Patients with IgA nephropathy had significantly raised concentrations of serum IgA compared to controls (Mann-WhitneyU test,P=0.001) and increased concentrations of conglutinin-binding IgA immune complexes (P=0.024). No differences in the median concentrations of IgG and IgM anti-IgA antibodies were found between the patients and the controls. In serum samples from healthy controls there was a significant positive correlation between IgM anti-IgA_p and IgA immune complex concentrations (P=0.05), which contrasted with the finding of an inverse correlation between IgM anti-IgA_p and IgA immune complex concentrations in patients with IgA nephropathy (P<0.05). In addition, the concentrations of conglutinin binding IgM immune complexes in serum were found to correlate with the concentration of IgM anti-IgA_p (0.010<P<0.025), IgM anti-IgA₁, and IgM anti-IgA₂ (P«0.005 for both) in patients with IgA nephropathy but not in controls. IgM anti-IgA antibodies may be important in augmenting the clearance of IgA immune complexes from the serum of patients with IgA nephropathy.     

Oligoclonally expanding gammadelta T lymphocytes induce IgA switching in IgA nephropathy

The aetiology of IgA nephropathy (IgAN) is closely related with abnormality of mucosal immunity. We investigated the roles of γδ T cells in the regulation of IgA production by B cells in IgAN patients. The proportion of γδ T cells in peripheral blood mononuclear cells (PBMNC) was higher in IgAN patients than in the controls and was found to be correlated with the proportion of surface IgA‐positive (sIgA+) B cells, which are precursors of IgA‐secreting plasma cells. After in vitro PWM stimulation, sIgA expression on B cells and IgA production were significantly enhanced in PBMNC obtained from IgAN patients, whereas the enhancements were abolished by removal of γδ T cells from the PBMNC. Purified γδ T cells from IgAN patients induced surface IgA expression on naïve sIgD+ B cells more effectively than did αβ T cells. Moreover, stimulated γδ T cells from IgAN patients produced a larger amount of TGF‐β1, which is one of the main cytokines that induces IgA class switching on B cells, as compared with αβ T cells and control γδ T cells. The expanded γδ T cells from IgAN patients exclusively expressed Vγ9, and the nucleotide sequences of junctional regions of Vγ9 showed very limited TCR diversities. It was therefore concluded that γδ T cells, which are expanded in response to specific antigens, enhance IgA class switching on B cells in IgAN patients.     

Clinicopathologic comparisons of IgA nephropathy and IgA vasculitis nephropathy in children: a ten-year single-center experience

Background/aim To investigate the similarities and differences of renal clinical and renal pathology between IgA nephropathy (IgAN) and IgA vasculitis nephritis (IgAVN) in children. Materials and methodsA total of 237 children with IgAN and 190 children with IgAVN were included. The general conditions, clinical characteristics, final diagnosis, clinical and pathological classification of the children were intercepted at the time of admission, and the retrospective comparative analysis was carried out. ResultsThe results showed that the median course of disease in IgAN group was longer than that in IgAVN group (p = 0.02). Patients with IgAN had a significantly higher duration of infection than the patients with IgAVN (p = 0.03). The white blood cell count (WBC), hemoglobin (HGB) in IgAN group were significantly lower than that in IgAVN group (p = 0.02). The serum creatinine in IgAN group was higher than that in IgAVN group (p = 0.02). Patients with IgAN and IgAVN had statistically significant differences in pathological typing between clinical types: hematuria and proteinuria, nephrotic syndrome and chronic nephritis (p = 0.004). ConclusionThe clinical manifestations of IgAN and IgAVN were similar, but the onset of IgAN was hidden and the clinical manifestations were relatively serious. Renal pathology was mainly glomerulosclerosis and renal tubular atrophy. IgAVN was characterized by acute onset and good renal function. Renal pathology was dominated by endothelial hyperplasia and crescent formation. These differences did not support the hypothesis that the two diseases are the same.     

Increased IL-10 production by stimulated whole blood cultures in primary IgA nephropathy

Most patients with primary IgA nephropathy (IgAN) have a significantly higher memory repertoire of IgA1-producing B lymphocytes in their bone marrow together with high plasma levels of IgA1. The connection between the mucosal immune system and the bone marrow compartment is probably based on traffic of either antigen-presenting cells (APC) or antigen-specific lymphocytes. Cytokines play an important role in the proliferation and differentiation of lymphoid cells. In order to mimic the in vivo situation as much as possible, we assessed cytokine production profiles ex vivo in 23 IgAN patients and matched controls, using lipopolysaccharide (LPS)- or phytohaemagglutinin (PHA)-stimulated whole blood (WB) cultures. Interferon-gamma (IFN-γ), IL-2, IL-6, IL-10 and tumour necrosis factor-alpha (TNF-α) production in culture supernatants were determined by cytokine-specific ELISAs. Compared with controls, PHA-stimulated cultures resulted in significantly higher IL-10 (P < 0.001), IL-2 (P < 0.005) and IFN-γ (P < 0.001) levels in IgAN patients, but no significant differences in TNF-α or IL-6 levels were found. In LPS-stimulated cultures, the only significant difference (P < 0.001) between the two groups was the increased IL-10 production in IgAN patients. The enhanced cytokine production in stimulated WB cultures suggests altered monocyte-related T cell responses in patients with IgAN. Increased IL-10 production may eventually result in an increased number of IgA-producing B lymphocytes in the bone marrow. In addition, high levels of endogenous IL-10 may down-regulate the effector functions of monocytes, or possibly APC in general, and consequently the IgA response at the mucosal level.     

Increased and prolonged production of specific polymeric IgA after systemic immunization with tetanus toxoid in IgA nephropathy.

IgA nephropathy (IgAN) is a chronic form of glomerulonephritis which is characterized by the deposition in the glomerular mesangium of polymeric IgA (pIgA), the source of which is unknown. In order to investigate the production of pIgA in IgAN, patients were immunized systemically with tetanus toxoid (TT). Two weeks after immunization patients and controls responded to TT with an IgA response of similar magnitude. HPLC separation of sera showed that patients with IgAN produce significantly more pIgA anti-TT than controls (7.7 versus 2.88 arbitrary units; P less than 0.04). At this time, 33% of serum IgA anti-TT produced by patients with IgAN was polymeric, compared with 21% produced by controls (P less than 0.02). Monomeric IgA (mIgA) anti-TT levels were similar in both groups. Four weeks after immunization the proportion of pIgA anti-TT in controls and patients was significantly reduced from the 2 week level (from 21% to 0%, P less than 0.02 for controls; and from 33% to 8%, P less than 0.001, for patients). Only four out of 12 controls had any detectable pIgA anti-TT at this time compared with nine out of 10 patients with IgAN (P less than 0.05), and IgAN patients produced proportionally more pIgA anti-TT than did controls (median 8%, interquartile ranges (IQR) 4-10% versus 0% IQR 0-3%; P less than 0.01). HPLC analysis under acid conditions did not alter the pattern of pIgA and mIgA anti-TT, suggesting that the high molecular weight IgA fraction was not due to complexes. These data indicate that circulating pIgA results (at least in part) from a systemic response to antigen, which may be exaggerated in IgAN.     

IgA肾病患者IL—2的产生及IL—2受体的表达

本文对IgA肾病(IgAN)外周血淋巴细胞白细胞介素2(IL-2)的产生、受体的表达及免疫球蛋白的产生进行了研究。结果发现:外周血淋巴细胞产生IL-2的活性明显增高,IL-2受体表达亦明显增强并伴有免疫球蛋白产生增多,提示IgAN存在着细胞免疫功能的紊乱。     

Altered production of IgE and IgA induced by IL-4 in peripheral blood mononuclear cells from patients with IgA nephropathy.

In order to elucidate the factors responsible for altered immunoglobulin production in patients with IgA nephropathy (IgAN), the in vitro effects of IL-4 and interferon-gamma (IFN-gamma) on the synthesis of IgE and IgA by peripheral blood mononuclear cells (PBMC) were studied. Spontaneous IgE and IgA synthesis by PBMC was significantly increased in patients with IgA nephropathy compared with controls. The maximum amounts of IgA and IgE synthesis by PBMC after stimulation with IL-4 were almost the same both in patients with IgAN and in controls. The enhancement rate of IL-4-induced IgE and IgA synthesis was significantly lower in IgAN than in the controls, suggesting in vivo preactivation of PBMC in IgAN patients. IFN-gamma suppressed IgA and IgE synthesis by PBMC from IgAN patients as well as controls. However, the suppressive effect on IgE synthesis was less prominent in patients with IgAN. These results suggested that altered IL-4 action might be involved in the development of IgA nephropathy.     

雷帕霉素抑制IgA肾病大鼠肾小球信号蛋白STAT3的活化

目的探讨雷帕霉素对IgA肾病大鼠肾组织p-JAK2、STAT3、p-STAT3和PCNA表达的影响。方法制备IgA肾病动物模型,分为对照组、IgA肾病组、氯沙坦(ls)和雷帕霉素(rapa)治疗组。监测大鼠的生化指标及用免疫组化、Western blot、RT-PCR等方法检测肾组织p-JAK2、STAT3、p-STAT3和PCNA的蛋白及mRNA的表达。结果IgA肾病大鼠较对照组24 h尿蛋白定量明显升高、血白蛋白降低、BUN以及Cr水平明显升高(P<0.01);IgA肾病大鼠p-JAK2、STAT3、p-STAT3和PCNA蛋白及mRNA水平也显著高于对照组;雷帕霉素能显著缓解上述改变(P<0.01)。结论雷帕霉素可能通过抑制IgA肾病大鼠肾小球JAK/STAT信号途径、直接抑制STAT3的活化以及抑制系膜细胞的增殖而减轻病变程度。     

Profiles of immunoregulatory cytokine production in vitro in patients with IgA nephropathy and their kindred.

We hypothesized that the altered immunoglobulin synthesis and/or lymphocyte function apparent in patients with IgA nephropathy (IgAN) is due to a primary defect in lymphokine regulation. In addition, we reasoned that such changes in lymphokine production might be, at least partially, genetically determined. To assess the extent of lymphocyte abnormalities, we investigated the profile of cytokine production from peripheral blood mononuclear cells (PBMC) in 34 IgAN patients and 44 of their first degree relatives, 10 of whom had persistent microhaematuria. Compared with healthy volunteers (n = 34), PBMC from patients showed increased IL-2 production both spontaneously or after phytohaemagglutinin (PHA) (20 micrograms/ml) stimulation, whereas IL-4 and interferon-gamma (IFN-gamma) production were significantly higher only after stimulation. Microhaematuric relatives had a similar pattern of cytokine production, whereas non-microhaematuric relatives showed no significant difference versus normals. The altered pattern of cytokine production appeared to be quite specific to IgAN patients and their microhaematuric relatives, because patients with other forms of primary glomerulonephritis (n = 17) did not differ from normal individuals. Patients and relatives that hyperproduced IL-4 were also hyperproducers of IL-2. No such congruence was seen in any other group or with any other pairing of cytokines. We propose that a subpopulation of IgAN patients bear lymphocytes intrinsically hyperresponsive. Among those individuals such hyperresponsiveness may be causally related to the pathogenesis and/or character of IgAN.     

Toll-like receptor 2 induces mucosal homing receptor expression and IgA production by human B cells

There is a need for developing vaccines that elicit mucosal immunity. Although oral or nasal vaccination methods would be ideal, current strategies have yielded mixed success. Toll-like receptor 2 (TLR2) ligands are effective adjuvants and are currently used in the Haemophilus influenzae type B vaccine. Induction of humoral immunity in the mucosa is critical for effective vaccination; thus, we sought to determine the effects of TLR2 ligands on human mucosal B cell differentiation. We demonstrate that TLR2 ligands induce CCR9 and CCR10 expression by circulating B cells and increased chemotaxis to cognate chemokines CCL25 and CCL28 suggesting that TLR2 induces B cell homing to the gastrointestinal tract. TLR2 stimulation of B cells also induced J chain and IgA production demonstrating the induction of mucosal-like antibody secreting cells. These observations suggest that vaccines containing TLR2-ligands as adjuvants could induce mucosal B cell immunity even when delivered in a non-mucosal manner.     

An associated molecule, p64, with high-affinity interleukin 2 receptor

TU11 mAb specific for the human interleukin-2 receptor (IL-2R) beta-chain, p75, co-precipitated two molecules, p64 and p55, with the beta-chain in the lysates of cells bearing the high-affinity IL-2R. The co-precipitation was detected in the presence of IL-2 even in the absence of a chemical cross-linker. H-48 mAb specific for the IL-2R alpha-chain completely pre-absorbed p64 as well as p55 and partially pre-absorbed the beta-chain from the lysates. The co-precipitation was also detected in phytohemagglutinin-stimulated normal peripheral blood lymphocytes, which express the high-affinity IL-2R, but not in the cell line cells bearing only the low-affinity IL-2R. The peptide maps indicate that p64 is a molecule distinct from both the alpha- and beta-chains, and that p55 is identical to the alpha-chain. These findings suggest that p64, along with the alpha- and beta-chains, is a component of the high affinity IL-2R complex, and we have tentatively named it the gamma-chain of IL-2R.     

A quantitative analysis of the mesangium in children with IgA nephropathy: sequential study

Quantitative analysis of the mesangial matrix and cells was performed on serial renal biopsies from 41 children with IgA nephropathy. In the repeat renal biopsy, nine patients showed a significant increase of mesangial matrix, 29 showed no change and in three there was a significant decrease. Eight of the nine patients (89 per cent) with a matrix increase had persistent proteinuria at the second biopsy, whereas only 14 of the 32 (44 per cent) without a matrix increase had persistent proteinuria (P less than 0.05). Although the mesangial matrix increased in patients with persistent proteinuria, there was no decrease in patients with clinical remission. In contrast to the mesangial matrix, mesangial cells significantly decreased in 23 patients, did not change in 16, and significantly increased in only two in the second biopsy. These findings suggest that mesangial matrix increase is usually an irreversible change and that persistent proteinuria is associated with matrix increase with worsening in glomerular morphology and clinical outcome. This study indicates the importance of serial renal biopsy in children with IgA nephropathy with persistent proteinuria.     

伤寒患者血清TNF,IL—2,sIL—2R水平的研究

为了解肿瘤坏死因子（ＴＮＦ）、白细胞介素２（ＩＬ－２）和可溶性白细胞介素２受体（ｓＩＬ－２Ｒ）在伤寒发病中的作用，以双抗体夹心法检测２７例伤寒患者及１６例正常人血清ＴＮＦ、ＩＬ－２和ｓＩＬ－２Ｒ水平。结果发现，伤寒患者血清ＴＮＦ水平和ｓＩＬ－２Ｒ水平均明显高于正常人水平（Ｐ＜０．０１）。而血清ＩＬ－２水平显著低于正常对照（Ｐ＜０．０１）。对１５例伤寒患者各病期血清ＴＮＦ、ＩＬ－２和ｓＩＬ－２Ｒ水平动态观察发现伤寒患者血清ＴＮＦ、ｓＩＬ－２Ｒ水平动态变化与患者体温、病期、病情变化具有密切关系。伴肝功能损伤和有诸如消化道出血、肺炎、急性肾衰等并发症及复发性伤寒的患者其血清ＴＮＦ、ｓＩＬ－２Ｒ水平明显高于无肝功能损伤及无并发症的患者。结果提示，临床检测伤寒患者血清ＴＮＦ、ｓＩＬ－２Ｒ除可协助诊断外，对于患者病情、病期、预后的判断及治疗效果的观察均具有重要意义，因此可作为临床观察伤寒病情及判断预后的监测指标。血清ＩＬ－２检测对于伤寒的诊断有一定帮助，但作为判断临床病情、病期及预后的指标意义不大     

中药方剂益肾汤对IgA肾病模型小鼠肾组织表达MMP-9、TIMP-1的影响

目的：探讨中药“益肾汤”治疗IgA肾病（IgAN）的机制。方法：用“口服牛血清白蛋白联合尾静脉注射葡萄球菌肠毒素B”法复制小鼠IgAN模型。设正常照、模型照、益肾汤低浓度和高浓度组共4组。FQ-RT-PCR法检测小鼠肾组织MMP-9、TIMP-1mRNA表达、免疫组化SABC法检测小鼠肾组织MMP-9、TIMP-1的含量。结果：模型组小鼠肾间质MMP-9表达与正常组无统计学意义,而模型组TIMP-1表达则明显上调,有统计学意义（P〈0.05）。益肾汤低浓度与高浓度组之间肾小管间质MMP-9、TIMP-1表达无统计学意义,但两组MMP-9表达均强于模型组（P〈0.05）,而TIMP-1的表达均弱于模型组（P〈0.05）。结论：益肾汤可促进小鼠肾小管间质MMP-9的表达、抑制TIMP-1的表达、促进ECM的降解,进而延缓IgAN肾小球硬化的进展。     

Decreased cervicovaginal production of both IgA1 and IgA2 subclasses in women with AIDS

Paired sera and cervicovaginal secretions from 35 HIV-1-infected women representing different CDC stages of HIV infection were evaluated for total IgA, IgA1 and IgA2, for IgA, IgA1 and IgA2 to gp160, and for albumin. Age-matched healthy women (n= 45) served as controls. The secretion rates of total IgA, IgA1 and IgA2 were evaluated by calculating their relative coefficients of excretion by reference to albumin. In HIV-infected women, total IgA1 and IgA2 in sera and in cervicovaginal secretions increased proportionately as early as stages II + III and more markedly at stage IV. By contrast, the secretion rates of total IgA, IgA1 and IgA2 were markedly reduced in AIDS women, the IgA2 secretion rate decreasing significantly as early as stages II +III. This apparent discrepancy was probably the result of increased transudation of serum-borne immunoglobulins into the vaginal cavity, since albumin levels in cervicovaginal secretions increased significantly according to the stages of disease. HIV-reactive IgA antibodies in serum, as in cervicovaginal secretions, were principally found within the IgA 1 subclass. In women at stage IV, a high local production of IgA1 to gp160 occurred in spite of the impairment of cervicovaginal IgA synthesis, probably because of marked genital HIV replication at advanced stages.