Seven new HLA-B alleles associated with antigens in the B7 CREG

This paper describes seven novel HLA-B alleles. Five of these new alleles contain polymorphic motifs previously reported in HLA-B alleles, suggesting an origin resultant from a gene conversion mechanism. B*0723 contains a polymorphism previously unreported in class I HLA molecules. B*4105 contains a nucleotide substitution previously unreported in class I HLA molecules, which encodes a protein sequence previously reported only in HLA-C locus alleles.     

Localization in situ of the co-stimulatory molecules B7.1, B7.2, CD40 and their ligands in normal human lymphoid tissue

Functional interactions between B and T lymphocytes are known to depend on the expression of co-stimulatory molecules B7.1/CD80, B7.2/CD86 and their counter-receptors CD28 and CTLA4, as well as CD40 and its ligand CD40L. To study the role of these molecules in situ, an immunohistochemical analysis was carried out on normal human lymphoid tissue. In the germinal centers (GC), B7.1 and B7.2 were differentially expressed. In the dark zone, centroblasts were predominantly B7.1⁺, while centrocytes in the light zone were B7-2⁺, resulting in reversed gradients of both markers in GC. Follicle mantle cells were negative for B7.1 and B7.2. Macrophages and interdigitating dendritic cells (IDC) in T cell zones both expressed B7.1 and B7.2. Moreover, clusters of B7.2⁺ T cells were demonstrated in interfollicular areas. Intrafollicular CD4⁺ T cells in GC, predominantly in the apical light zone, expressed CD28 and CTLA4, as did the majority of interfollicular T cells. CTLA4 showed a striking excentric cytoplasmic staining, which was also seen on T cells activated in vitro. CD40 was expressed on all B cells and more strongly on macrophages and IDC. Moreover, small clusters of T cells in a rim outside the GC showed CD40 expression. CD40L was expressed both on intrafollicular CD4⁺ T cells as well as on T cells in T cell zones. The differential distribution of co-stimulatory molecules in different compartments of normal human lymphoid tissue in situ indicates that these interactions play a distinctive role in different stages of B cell differentiation and in the immune response.     

Native and sialic acid masked Lewisa antigen reactivity in medullary thyroid carcinoma

Forty-six medullary thyroid carcinomas (MTC) were subjected to a qualitative and quantitative characterization of native and sialic acid masked Lewis^a (Le^a) antigens. Immunohistochemical investigations included monoclonal antibodies (MABs) directed against alpha(2,3)-sialyl-Le^a, i.e. CA19-9 (MAB 19-9), native Le^a (MAB anti Le^a) and alpha(2,3) sialyl type 1 structure, i.e. CA 50 (MAB C50). To detect sialic acid masked Le^a reactivity, MAB anti-Le^a was also applied to native and enzymatically desialylated tissue sections with and without masking of sialic acid residues by sialic acid and sequence specific lectins. Only 7 MTC (15%) displayed a weak expression of CA19-9, while 16 (33%) showed moderate positive staining for native Le^a. Twenty-seven tumours exhibited a strong staining by the N'ase MAB anti Le^a staining sequence. The latter could most effectively be inhibited by the simultaneous masking of alpha(2,3)-and alpha-(2,6)-linked sialic acid residues due to the comptetitive binding of sialic acid and sequence specific lectins: Maackia amurensis agglutinin (specific alpha(2,3)-linked sialic acid) and Sambucus nigra agglutinin (specific alpha(2,6)-linked sialic acid). Thus, in MTC the major portion of sialic acid masked Le^a antigen reactivity is different from that detected by the MAB 19-9. The antigen reactivity is probably due to Le^a structures containing both alpha(2,3) and alpha(2,6)-linked sialic acid residues. A highly significant correlation between the expression of CA50 and that detected by the N'ase MAB anti-Le^a staining sequence indicates that the alpha(2,3)-sialyl type 1 chain represents a common intermediate structure within the pathway of the biosynthesis of sialylated Le^a antigens, excluding the formation of CA19-9 via the formation of the disialyl type 1 structure. This is subsequently fucosylated to the corresponding sialic acid masked Le^a. Preliminary clinicopathological studies indicate that the sialic acid masked Le^a antigens detected by the N'ase MAB anti-Le^a staining sequence are related to biologically aggressive MTC.     

Isolation and characterisation of a defective measles virus from a subacute sclerosing panencephalitis patient.

A cytopathic measles virus was isolated from a brain biopsy of a subacute sclerosing panencephalitis (SSPE) patient. The agent could be transferred to Vero cells by cocultivation, but the infectivity always remained cell-associated -ie, a defective virus infection. The cell-associated nature of the virus was retained through 25 passages in Vero cells. Intracerebral inoculation of hamsters (2-6 days old) with the cocultured Vero cells gave rise to 100% mortality in 5-7 days. The virus retained its cell-associated nature after passage in hamsters. Electron microscopy of the brain and Vero cocultures showed the presence of virus-like ribonucleoparticles mainly in the nucleus. The presence of viral antigens in the nucleus, cytoplasm, and on the plasma membranes was confirmed by immunofluorescence. Using a combination of immunological and biochemical techniques, it was shown that all the viral proteins were synthesized with the exception of the haemagglutinin. Inclusion of the fusion inhibitor SV4814 (CBZ-D phenylalanine-L-phenylalanine-L-arginine-NO2) in the culture medium led to the elimination of the SSPE infection.     

Human Diversity of Killer Cell Immunoglobulin-Like Receptors and Human Leukocyte Antigen Class I Alleles and Ebola Virus Disease Outcomes

We investigated the genetic profiles of killer cell immunoglobulin-like receptors (KIRs) in Ebola virus–infected patients. We studied the relationship between KIR–human leukocyte antigen (HLA) combinations and the clinical outcomes of patients with Ebola virus disease (EVD). We genotyped KIRs and HLA class I alleles using DNA from uninfected controls, EVD survivors, and persons who died of EVD. The activating 2DS4–003 and inhibitory 2DL5 genes were significantly more common among persons who died of EVD; 2DL2 was more common among survivors. We used logistic regression analysis and Bayesian modeling to identify 2DL2, 2DL5, 2DS4–003, HLA-B-Bw4-Thr, and HLA-B-Bw4-Ile as probably having a significant relationship with disease outcome. Our findings highlight the importance of innate immune response against Ebola virus and show the association between KIRs and the clinical outcome of EVD.     

人心肌肌凝蛋白重链的制备研究

目的：探讨制备人心肌肌凝蛋白重链（MHC）的方法,为制备其抗体提供抗原。方法：采用改良性制备人心肌MHC,通过SDS-PAGE及Western印迹分析其纯度及抗原特性。结果：①SDS-PAGE显示,纯化的人心肌MHC呈现只有一分子量较大的代表人心肌MHC带的典型图像;②Western印迹显示,200ku处有一典型的感光带。结论：所用的改良法能有效地提取纯化人心肌MHC,可满足制备其抗体的需要。     

Vaccination with chimeric protein induces protection in murine model against ascariasis

An estimated 400 million people are infected by parasites of the genus Ascaris and the existing control measures are inefficient. Vaccine development using B cell antigens is a promising strategy for increased protection against this parasite. The present study aimed at developing a chimeric protein capable of conferring protection against infection by Ascaris sp. For this purpose, we performed B-cell epitope predictions on previously described vaccine candidate proteins from Ascaris suum and the corresponding peptides were used to construct a chimeric protein. Female BALB / c mice were immunized subcutaneously in three doses at 10 day intervals with a vaccine formulation comprised of the chimeric protein together with monophosphoryl lipid A (MPLA). Control groups included protein alone, MPLA, or PBS. After challenge infection, animals vaccinated with chimeric protein plus MPLA showed a reduction of 73.54% of larval load in the lung compared to control group animals. Animals immunized with chimeric protein plus MPLA also display higher IgG response and a reduction in lung inflammation. Our study highlights how chimeric proteins containing more than one B cell epitope can enhance immune protection against helminthic infection and offer new approaches to the development of Ascaris vaccines.