淋巴结分支杆菌性梭形细胞假瘤

目的 探讨淋巴结分支杆蓖性梭形细胞假瘤的临床病理特征。方法 对2例淋巴结分支杆菌性梭形细胞假瘤,常规石蜡切片,HE、抗酸染色,免疫组织化学标记,光镜观察。结果 患者均系1岁婴儿,无免疫缺陷疾病和使用免疫抑制剂史,出生1个月后接种卡介苗,临床表现：腋下淋巴结结节性肿大伴发热,病理表现：淋巴结肉梭形细胞束状或席纹状增生伴有淋巴细胞、浆细胞、中性粒细胞浸润和增生的毛细血管,形成梭形细胞假瘤,抗酸染色显示病变内大量分支杆菌,免疫组织化学标记梭形细胞Mac387和溶菌酶强阳性、S-100阴性。结论 在免疫功能低于或缺陷患者（如AIDS）和婴儿接种卡介苗后,可以发生淋巴结分支杆菌性梭形细胞假瘤,该病应与淋巴结的原发性梭形细胞肿瘤鉴别,确诊对其治疗十分重要。     

Monocytes modulate enhancement of HIV-1 replication by Mycobacterium tuberculosis

To investigate the effects of Mycobacterium tuberculosis on HIV-1 replication, peripheral blood mononuclear cells (PBMC) of bacille Calmette–Guérin (BCG)-vaccinated donors and non-BCG-vaccinated donors were infected in vitro with a lymphotropic isolate of HIV-1 and cultured in the presence of purified protein derivative (PPD). Addition of PPD resulted in enhanced HIV-1 replication and lymphoproliferation in BCG-vaccinated donor PBMC, while PPD had no such effects in control PBMC. HIV-1 replication increased even more when monocytes were removed from PBMC, while lymphoproliferation was decreased. High percentages of monocytes were associated with a decreased HIV-1 replication and proliferation that could not be reversed by addition of antibodies against the cytokines IL-1, transforming growth factor-beta (TGF-β) or indomethacin. PPD stimulates PBMC to release IL-10, a cytokine known to down-regulate proliferation and HIV-1 replication. PPD-induced effects on proliferation as well as HIV-1 replication could be partially blocked by adding a monoclonal antibody against MHC class II molecules, suggesting that part of the mechanism of PPD-induced enhancement is T memory cell activation.     

No associations of human pulmonary tuberculosis with Sp110 variants

Background

After a recent report on the role of the Ipr1 gene in mediating innate immunity in a mouse model of Mycobacterium tuberculosis infection, the human Ipr1 homologue, Sp110, was considered a promising candidate for an association study in human tuberculosis.

Methods

In a sample of >1000 sputum positive, HIV negative West African patients with pulmonary tuberculosis and >1000 exposed, apparently healthy controls, we have genotyped 21 Sp110 gene variants that were either available from public databases, including HapMap data, or identified by DNA re‐sequencing.

Results

No significant differences in the frequencies of any of the 21 variants were observed between patients and controls. This applied also for HapMap tagging variants and the corresponding haplotypes, when including sliding window analyses with three adjacent variants, and when stratifying controls for positivity and negativity according to the results of intradermal tuberculin (purified protein derivative, PPD) skin tests. DNA re‐sequencing revealed 13 novel Sp110 variants in the 5′‐UTR, exons, and adjacent intronic regions.

Conclusions

Based on the results obtained in this case‐control study, the hypothesis that Sp110 variants and haplotypes might be associated with distinct phenotypes of human M tuberculosis infection is doubtful.     

Defects in antigen-driven lymphocyte responses in common variable immunodeficiency (CVID) are due to a reduction in the number of antigen-specific CD4+ T cells.

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 109,000 T cells compared with 1 in 18,600 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.     

Failure in antigen responses by T cells from patients with common variable immunodeficiency (CVID).

Antigen-driven responses by T cells from patients with CVID and normal subjects have been assessed. Low-density cells enriched for antigen-presenting dendritic cells were cultured with T cells using a 20-microliters hanging drop system. T cells from all subgroups of CVID patients showed markedly reduced responses to the recall antigens purified protein derivative (PPD) or tetanus toxoid, whereas responses by cells from patients with X-linked agammaglobulinaemia, used as a disease control, were in the normal range. However, primary allo-stimulation of CVID T cells was normal. CVID cells from two patients failed to respond to stimulation with a neoantigen, an HIV env peptide, under conditions where normal T cells did respond. These data illustrate a profound defect in antigen-stimulated T cell proliferation in vitro in all groups of CVID patients, but do not distinguish whether the defect is in the presenting cell or in the T lymphocyte. In vivo, germinal centre B cells are thought to present antigen to primed T cells to obtain essential signals (e.g. CD40 ligand and IL-2) for B cell survival and progression to immunoglobulin secretion. A failure of antigen-specific T cell function in vivo in CVID would thus not provide the primed T cells needed for B cell rescue, and could be the primary defect leading to the low immunoglobulin production in this condition.     

Preparation of T-lymphocyte lines and clones with specificities to preselected protein sites by in vitro passage with free synthetic peptides: Demonstration with myoglobin sites

Recently, this laboratory has demonstrated that antibodies to preselected regions of a protein can be obtained by immunization with free small synthetic peptides (6–7 residues) without conjugation to a carrier. In the present work, we report the use of free synthetic peptides representing myoglobin (Mb) antigenic sites to prepare T-cell lines and clones of preselected specificities. Lymph node cells from mice primed $\text{in vivo}$ with sperm-whale Mb were periodically passaged $\text{in vitro}$ with synthetic peptide. After several passages, the peptide-driven long term T-cell cultures responded to the intact protein and exclusively to the peptide that was used to drive the cells. From these cultures, T-cell clones were prepared that responded only to the driving peptide and to the whole protein. The ability to prepare T-cell lines and T-cell clones with preselected submolecular specificities to a protein by driving cultures with desired synthetic peptides affords an important and simple tool for basic immunological investigations and for clinical applications.     

Recruitment of dendritic cells to pathological niches in inflamed liver

The liver is a specialized organ for host defense and immunity. Recruitment of dendritic cells (DCs) is crucial to host defense in a granulomatous liver disease in mice. In response to danger signals, DC precursors are mobilized de novo into the circulation. Myeloid DC (mDC) precursors are recruited to perisinusoidal spaces and activated to form granulomas. Recruited mDCs subsequently extravasate into Disse’s space and migrate to the portal area to induce portal tract-associated lymphoid tissue (PALT). Some mDCs are remobilized into draining hepatic lymph nodes (LNs) to prime antigen-specific CD4⁺ helper T cells. Kupffer cell-derived CCL3/MIP-1α attracts mDC precursors to the sinusoidal granulomas, whereas PALT composed cell-derived CCL21/SLC attracts activated mDCs to the T-cell zone of PALT. Inflammatory cytokines modulate this sinusoid-portal migration through IL-1R/TLR signaling. Recruited mDCs themselves also produce several chemokines and cytokines that modulate T-cell responses. A unique trafficking of circulating mDC precursors within the inflammation-associated, newly formed compartments (“pathological niches”) is strictly regulated by both homeostatic and inducible chemokines and determines the final efficiency of the immunity in this organ.     

miRNAs and HIV: unforeseen determinants of host-pathogen interaction

Our understanding of the complexity of gene regulation has significantly improved in the last decade as the role of small non-coding RNAs, called microRNAs (miRNAs), has been appreciated. These 19–22 nucleotide RNA molecules are critical regulators of mRNA translation and turnover. The miRNAs bind via a protein complex to the 3′ untranslated region (3′ UTR) of mRNA, ultimately leading to mRNA translational inhibition, degradation, or repression. Although many mechanisms by which human immunodeficiency virus-1 (HIV-1) infection eventually induces catastrophic immune destruction have been elucidated, the important role that miRNAs play in HIV-1 pathogenesis is only now emerging. Accumulating evidence demonstrates that changes to endogenous miRNA levels following infection is important: in maintaining HIV-1 latency in resting CD4⁺ T cells, potentially affect immune function via changes to cytokines such as interleukin-2 (IL-2) and IL-10 and may predict disease progression. We review the roles that both viral and host miRNAs play in different cell types and disease conditions that are important in HIV-1 infection and discuss how miRNAs affect key immunomodulatory molecules contributing to immune dysfunction. Further, we discuss whether miRNAs may be used as novel biomarkers in serum and the potential to modulate miRNA levels as a unique approach to combating this pathogen.     

PPD对人内皮细胞与外周血单个核细胞粘附的影响

为探讨热休克蛋白 6 0kD在动脉粥样硬化早期形成机制中的作用 ,本实验采用病原微生物同源性蛋白即结核杆菌纯化蛋白衍生物 (PPD ) ,观察其在人脐静脉内皮细胞 (EC )和外周血单个核细胞 (PBMC )粘附过程中的作用。利用培养的人脐静脉内皮细胞株 ,测定人PBMC和EC的粘附率 ;采用McAbCD5 4和McAbIL 1β抑制试验 ,检测PPD对EC表达粘附分子的作用。结果显示 ,经PPD处理的EC对PBMC的粘附率增加 ,并有一定的时相关系 ,粘附分子ICAM 1在EC表面表达增加 ;McAbCD5 4可以降低PPD的EC和PBMC的粘附率 ,而McAbIL 1β对粘附率没有影响。PPD可以直接刺激EC表达粘附分子CD5 4,进一步参与介导白细胞与内皮细胞的粘附。     

Mycobacterial infections in adult recipients of allogeneic hematopoietic stem cell transplantation: A cohort study in a high endemic area

BackgroundMycobacterial infections are important and potentially life-threatening complications after organ transplantations. Notably, for the recipients of allogeneic hematopoietic stem cell transplantation (HSCT), there are a few supporting results to explore post-transplant mycobacterial infections. Taiwan is a high endemic area of the infection. We aim to investigate the incidence, risk factors, and survival of post-transplant mycobacterial infections, including mycobacterium tuberculosis (MTB) and non-tuberculous mycobacterium (NTM).MethodsWe included 422 adult patients undergoing allogeneic HSCT at an Asian tertiary medical center between January 2003 and December 2014. A total 26 subjects developed post-transplant mycobacterial infections. Risk factors, clinical features, and survival for post-transplant mycobacterial infections were collected and analyzed.ResultsPost-transplant mycobacterial infections occurred in 26 (6.2%) of 422 HSCT patients. Two-year cumulative incidences in MTB and NTM were 1.4% and 5.4%. In the multivariate analysis, being age >45 years (adjusted HR 2.21, 95% CI 1.01–4.83) and extensive chronic graft-versus-host disease (cGVHD) (adjusted HR 4.95, 95% CI 2.14–11.46) were identified as independent risk factors of infections. There was a trend as a risk factors in relapsed patients (P = 0.088). For patients with cGVHD, there was a significant difference of post-transplant survival between mycobacterial infections and none (P = 0.036). Pneumonia contributed most to mortality (n = 11, 42.3%).ConclusionMycobacterial infections are worth to note in a high endemic area. Once a high-risk group is identified, much effort is required to target new approaches for prevention, early detection and treatment of infections.     

Mycobacterial testing in hospital laboratories: results from a questionnaire survey in Italy

Between 1999 and 2001, 355 hospital laboratories in Italy were asked to complete a questionnaire addressing mycobacterial test methods, 1-year workloads and laboratory safety features. Analysis of the data showed that rapid methods for mycobacterial testing were being used by most larger laboratories; however, sub-optimal methods were still in use in small and medium-size laboratories. In a country such as Italy, which has a low prevalence of tuberculosis cases, implementation of rapid technologies, combined with regionalisation of mycobacterial diagnostic services, seems to be the most reasonable and cost-effective strategy.     

Malaria vaccine: Immunization of mice with a synthetic T cell helper epitope alone leads to protective immunity

The immunogenicity of the non-repetitive sequences of the Plasmodium berghei circumsporozoite (CS) protein was studied using synthetic peptides. Two CS sequences (residues 20-39 and 57-70) exhibiting T cell helper activity were identified. Immunization of BALB/c mice with a branched peptide containing either the 20-39 or the 57-70 sequence and two repeats (B epitope) in a linear sequence induced high titers of anti-repeat and anti-sporozoite antibodies. Mice immunized with the T-B construct (high antibody titers) or with the 57-70 epitope alone (no serum anti-repeat or anti-peptide antibodies) were protected to a similar degree after challenge with infective sporozoites. No protection was obtained in mice immunized with the 20-39 epitope. These results indicate that BALB/c mice can be protected either by effector T cells or by high levels of anti-repeat antibodies. Thus, in the same strain, a double mechanism of protection can be obtained by a synthetic peptide vaccine.     

Identification of human T cell epitopes in the Mycobacterium leprae heat shock protein 70-kD antigen.

In a number of pathogens, heat shock proteins (hsp) stimulate humoral and cellular immune responses despite significant sequence identity with host hsp. The 70-kD hsp of Mycobacterium leprae, which shares 47% identity with human hsp70 at the protein level, elicited a T cell response in most Myco. bovis (bacille Calmette-Guérin (BCG)) vaccinees as well as leprosy and tuberculosis patients and their contacts. In order to locate T cell epitopes, DNA fragments encoding portions of the 70-kD hsp were expressed in the vector pGEX-2T and tested for T cell reactivity in an in vitro proliferative assay. Cultures of peripheral blood mononuclear cells (PBMC) from BCG vaccinees indicated that the C-terminal half of the molecule contained multiple T cell epitopes, as the T cells from a majority of Myco. leprae hsp70-reactive individuals responded to C-344. Lower proportions of patients with paucibacillary leprosy (36%) and tuberculosis patients (16%) responded to C-344. The smaller C-142 fragment which includes the terminal 70 residues unique to Myco. leprae and is the target for the human antibody response elicited a cellular response in few patients and no vaccinees. In order to map T cell epitopes, two series of synthetic peptides encompassing the region 278-502 were prepared. Using overlapping 12mer and 20mer peptides, this region of the molecule was found to contain several potential T cell epitopes. The longer peptides gave a clearer indication of reactive sequences including regions of the molecule which were not identified with the 12mer peptides. Fine mapping of reactive peptide pools using the 12mer peptides identified two T cell epitopes. Although both were located in regions of the molecule shared with Myco. tuberculosis, one appeared to be cross-reactive with the equivalent human sequence, and thus has the potential to initiate autoimmune responses.     

Differential antigen recognition by T cell populations from strains of mice developing polar forms of granulomatous inflammation in response to eggs of Schistosoma mansoni

In humans, infection with schistosome helminths can lead to dissimilar forms of clinical disease. Likewise, in the experimental mouse system, identical infection protocols with Schistosoma mansoni cause a more severe granulomatous disease in the C3H strain than in the C57BL/6 strain. To address this difference, we developed panels of schistosomal egg antigen (SEA)-specific T cell hybridomas to compare the responses of C3H and C57BL/6 mice to the major egg antigen p40. All derived C3H T cell hybridomas, despite being clonally distinct and restricted by either I-A^k or I-E^k, responded to recombinant fragment 15-1 of the p40 antigen, while none of the C57BL/6 T cell hybridomas did. Consistent with the observed monoclonal T cell responses, polyclonal lymph node cells from schistosome-infected C3H mice reacted strongly to fragment 15-1, which contrasted sharply with the weak response displayed by the C57BL/6 strain. Moreover, studies with congenic mice demonstrated that the strong CD4⁺ T cell response to fragment 15-1 was under major histocompatibility complex control and segregated with the H-2^k haplotype. These findings suggest that a dominant T cell response against a major egg antigen may represent a risk factor for the development of severe disease.     

Quantitation of helper factor activity. II. Inhibition of antibody binding

A sensitive direct assay has been developed to quantitate antigen specific helper factors (ThF). The assay depends on the ability of ThF to block the binding of free antibody to immobilized antigen. It has been used to follow the course of purification of ThF produced in short-term cultures of in vitro primed helper cells and purified by affinity chromatography on antibody and antigen immunoabsorbents. The identity of the ThF was confirmed by assaying its biological activity and by its reactivity with anti-Ia antibody and with a monoclonal anti-ThF.     

重组卡介苗表达的MalE蛋白T细胞表位的鉴定

目的 鉴定重组卡介苗表达的MalE蛋白T细胞表位。方法 用抗原提呈试验、T细胞增殖试验、ELISPOT试验和表位作图测试重组MalE蛋白的T细胞表位。结果 重组BCG.MalE功能性表达了MalE蛋白的4种H-2^d限制性T细胞表位。结论 在4种表位中，p68-82是重组MalE蛋白的主要T细胞表位，而其余3个为次要表位。     

Negative images of mycobacteria in aspiration biopsy smears from the lymph node of a patient with acquired immunodeficiency syndrome (AIDS): Report of a case and a review of the literature

Negative images of acid-fast bacilli were observed in Diff-Quik-stained smears of lymph node aspirates from a patient with acquired immunodeficiency syndrome (AIDS) and disseminated Mycobacterium avium-intracellulare infection. The significance of this finding in relation to the diagnosis and treatment of this infection is discussed and the literature pertaining to this observation is reviewed.     

Serological distinction of integral plasma membrane proteins as a class of mycobacterial antigens and their relevance for human T cell activation

This study pertains to classification and antigenic analysis of mycobacterial plasma membrane proteins in relation to human T cell proliferative responses, using a ‘fast grower’ Mycobacterium fortuitum as model. Membrane vesicles, prepared by sonication and differential centrifugation, were subjected to biphasic Triton X-1 14 extraction for isolation of integral (detergent phase) and peripheral (aqueous phase) proteins. Neither protein pool showed any appreciable overlap serologically. SDS-PAGE showed five prominent bands in peripheral and three in the integral protein pool, whereas immunoblotting with rabbit antisera identified only two major antigens (60 and 67kD) in the former and five (24, 34, 42, 51 and 54kD) in the latter, ELISA with a panel of anti-mycobacterial MoAbs revealed that nine out of 12 previously known antigens were present in the peripheral protein pool. Only two of them (33 and 40 kD) were additionally detected amongst integral proteins. The membrane-associated immunosuppressive moiety lipoarabinomannan was semiquantitatively located in aqueous phase. In bulk T cell proliferation assays, seven out of 10 subjects belonging to a ‘responder’ background (BT-BB leprosy patients and healthy contacts) showed high responses for Myco. fortuitum antigens. Proliferative response with integral proteins was comparable to that with whole membrane, hut it was significantly higher (P < 0.0005) than t he response with peripheral proteins. The distinction and relevance of integral membrane proteins as a class of mycobacterial antigens make them worthy of consideration in a subunit vaccine design.     

Presentation of viral antigens by human vascular endothelial cells in vitro

Endothelial cells (EC) separated from the umbilical vein were shown to be free of contaminating monocytes. EC could replace periferal blood-derived macrophages as antigen-presenting cells for in vivo sensitized T cells towards a variety of viral antigens. The T-cell-EC-antigen response was also specificity inhibited by anti-HLA-DR antisera. T cells primed by antigen together with autologous macrophages could be restimulated by antigen pulsed HLA-D/DR identical EC in an antigen specific secondary response, indicating a similar mechanism for antigen presentation by EC or macrophages.     

Suppression of adjuvant arthritis in rats by induction of oral tolerance to mycobacterial 65-kDa heat shock protein

Oral administration of mycobacterial 65-kDa heat shock protein (HSP) given daily for 5 days prior to immunization with Mycobacterium tuberculosis (Mt) suppressed the development of adjuvant arthritis (AA) in rats. AA was significantly suppressed by 30 and 300 μg HSP, and variably by 0.3, 3 μg or 1 mg. Histological analysis of joint samples obtained from control and test rats confirmed the suppression of AA in the fed group. Feeding Mt or hen egg lysozyme (HEL) failed to affect AA, indicating that the suppression was HSP specific. The oral administration of 30 μg HSP decreased both delayed-type hypersensitivity (DTH) reactions and proliferative responses to HSP and Mt. In addition, the proliferation of lymph node cells (LNC) from Mt-sensitized rats was inhibited by the addition of spleen cells (SPC) from HSP-fed animals, possibly by the secretion of transforming growth factor (TGF)-β. Spleen cells obtained from tolerized donors were capable of transferring the tolerance to naive recipients. These results demonstrate that feeding HSP is an effective way to suppress AA and that the suppression of AA may be mediated by regulatory T cells generated following oral administration of mycobacterial 65-kDa HSP.