Host Markers Research Articles

Cellular immune responses in Helicobacter heilmannii infection: evaluation of the role of the host and the bacterium.

We evaluated some aspects of the immune response to Helicobacter heilmannii in two mouse strains. Gastritis that was more severe in infected C57BL/6 mice. A proliferative response to H. pylori antigens was observed in splenocytes from H. heilmannii-positive and -negative mice, similar in the positive- and negative-BALB/c mice, but lower in the positive- than in the negative-C57BL/6 animals. A decrease in B cells and an increase in CD4+ cells after stimulation with type I H. pylori antigen and an increase in CD8+ cells after stimulation with type I and II antigens was observed in infected C57BL/6 mice. Conversely, the percentage of CD4+, CD8+, and B cells was similar in positive- and negative-BALB/c mice. These results demonstrated that the immune response is similar in H. heilmannii and H. pylori infection and strengthened the importance of host and bacterial virulence markers in the immune response to gastric Helicobacter infections.

Cellular Compartments of Human Immunodeficiency Virus Type 1 Replication In Vivo: Determination by Presence of Virion-Associated Host Proteins and Impact of Opportunistic Infection

Antigens derived from host cells are detectable in the envelope of human immunodeficiency virus type 1 (HIV-1) and result in a distinctive viral phenotype reflecting that of the host cell. An immunomagnetic capture assay targeting discriminatory host proteins was developed to differentiate between HIV-1 derived from macrophages and lymphocytes. HIV-1 propagated in macrophages or lymphocytes in vitro was selectively captured by monoclonal antibodies directed against the virally incorporated cell-type-specific host markers CD36 (macrophages) and CD26 (lymphocytes). Furthermore, by targeting these markers, virus of defined cellular origin was selectively captured from a mixed pool of in vitro-propagated viruses. This technique was further refined in order to determine the impact of opportunistic infection on HIV-1 expression from these cellular compartments in vivo. Analysis of cell-free virus purified from plasma of patients with HIV-1 infection suggested that in those with an opportunistic infection, viral replication occurred in activated lymphocytes. Interestingly, there was also significant replication in activated macrophages in those patients with untreated pulmonary tuberculosis. Thus, in addition to lymphocytes, the macrophage cellular pool may serve as an important source of cell-free HIV-1 in patients with opportunistic infections that lead to marked macrophage activation. This novel viral capture technique may allow researchers to address a wide range of important questions regarding virus-host dynamics.

Aberrant Expression of a Cytokeratin in a Subset of Hepatocytes during Chronic WHV Infection

Chronic infection of woodchucks with woodchuck hepatitis virus (WHV) invariably leads, within 2–4 years, to the appearance of hepatocellular carcinoma (HCC). HCC is preceded by an extended period of chronic liver damage, probably resulting from the immune response to viral antigens. It may be that infection itself also induces changes in the hepatocyte population. To begin to identify some of the changes in the liver prior to the appearance of HCC, monoclonal antibodies (MAbs) were generated from mice immunized with hepatocytes from a woodchuck chronically infected with WHV or with a tumor lysate. Immunofluorescence microscopy was used to select MAbs that reacted with host markers whose patterns of expression would distinguish chronically infected from uninfected liver or from liver tumors. One of these MAbs (2F2) reacted strongly with a subset of hepatocytes in chronically infected liver; a similar staining pattern was not detected in uninfected or transiently infected liver. Evidence is presented that this strong staining reaction reflects the overexpression or accumulation of the hepatocyte-specific intermediate filament protein, cytokeratin K18, a protein previously implicated in cryptogenic cirrhosis of the liver in humans (Ku, N. O., Wright, T. L., Terrault, N. A., Gish, R., and Omary, M. B.J. Clin. Invest.99: 19–23, 1997). Double immunofluorescent staining with antibodies to K18 and M-envelope protein of WHV suggested that strong reactivity to K18 was limited to cells expressing high levels of one or both of the large viral-envelope proteins, M and L; however, high expression of these viral proteins was not always associated with a strong K18 staining reaction.

A comparative study on the frequency of prophages among natural isolates of Salmonella and Escherichia coli with emphasis on generalized transducers.

Several collections of natural isolates of the genus Salmonella and of the species Escherichia coli were studied for the release of viable temperate phages. The results indicated that functional prophage genomes may be a common constituent of all bacterial genomes of the investigated strains. About 99% of the Salmonella phages are capable of generalized transduction of chromosomal host markers and plasmids. The ratio of transducing E. coli phages is significantly lower.

Soluble CD16 (sCD16), a marker of malignancy in individuals with monoclonal gammopathy of undetermined significance (MGUS).

There are no well-defined host markers to determine which patients with a diagnosis of monoclonal gammopathy of undetermined significance (MGUS) will progress to multiple myeloma (MM). In this preliminary study we measured plasmatic soluble Fe gamma receptor type III (sFe gamma RIII or sCD16) in 54 individuals with MGUS. 35 patients with multiple myeloma (MM) and 29 healthy controls. We confirmed, through receiver operating characteristic (ROC) curve analysis, that a low level of sCD16 discriminates MM patients from controls. Indeed, for a sCD16 value of 1.3 micrograms/ml, the sensitivity, as well as the specificity, of this discrimination were both equal to 83%, i.e. 83% of MM patients had a plasmatic sCD16 value < 1.3 micrograms/ml compared with only 17% of controls. Moreover, ROC curve analysis showed that a low sCD16 level also identifies among MGUS patients a subgroup of patients who rapidly progress towards multiple myeloma: in this comparison, for a sCD16 level of 1.3 micrograms/ml. sensitivity and specificity were 70% and 79% respectively. Therefore a low sCD16 level in MGUS indicated a high likelihood of rapid evolution of MM. In contrast to sCD16, soluble IL-6R did not appear to be discriminant in this study.

Bacteria as Risk Markers for Periodontitis.

Specific microbial species have been closely associated with periodontitis. Through longitudinal studies, some of these microbial species have been implicated in the etiology of progressive periodontal disease. Although putative periodontal pathogens are often isolated from individuals with severe periodontitis, they also frequently inhabit the subgingival environment and are not always associated with advanced disease. In this respect, it is becoming increasingly apparent that there is no single etiology of the various periodontal diseases. Destructive periodontal diseases are the result of environmental, host, and bacterial factors. Microorganisms, however, are essential components of any model for progressive periodontitis. This paper selectively reviews bacteria as risk markers for periodontitis. Attention focuses on bacteria in conjunction with behavioral patterns (oral hygiene habits and smoking) and host response (gingival crevicular fluid substances) as risk markers for periodontitis. Prospective studies implicating specific bacteria in progressive periodontitis are addressed and a bacterial risk assessment model for progressive periodontitis is discussed with respect to the interplay between bacterial, environmental, and host markers. J Periodontol 1994; 64:498-510.

Host Markers and Prognosis in Recurrent Rectal Carcinomas Treated with Radiotherapy

The value of blood tests as prognostic factors in patients with recurrent rectal carcinomas treated with radiotherapy was studied in one retrospective (n = 114, 1976-1984) and one prospective (n = 100, 1985-1989) group of patients. The retrospective group was used for validation of the results from the prospective group. In univariate survival analyses, 19 of totally 38 variables significantly correlated to the survival. Of 13 significant blood parameters, lactate dehydrogenase (LD), erythrocyte sedimentation rate (ESR), alpha 1-, alpha 2-globulin, fibrinogen, carcinoembryonic antigen (CEA), C-reactive protein (CRP), haptoglobin, granulocytosis and thrombocytosis were the most important ones (p < or = 0.01). In the multivariate analyses (Cox regression) of the prospective group, LD, alpha 1-globulin, diagnosed liver metastases and CEA were found to be significant predictors of survival. A prognostic index was derived from the prospective group including ESR, LD and relapse-free interval. This clearly separated the patients in the retrospective group into one low- and one high-risk group.

Virulence factors in Escherichia coli from urinary tract infections in patients with spinal injuries

A collection of 70 strains of Escherichia coli from urinary tract infections in spine-injured patients undergoing long-term bladder catheterization were tested for characteristics that have been associated with the ability to produce pyelonephritis. The incidence of the virulence factors were: mannose-resistant haemagglutinins (30%), P-fimbriae (17%), haemolysin (27%), K-antigens (28%) and aerobactin (by bioassay 33%, by gene probe 39%). Only 54% of the strains belonged to the O-serotypes usually associated with urinary tract infections. E. coli carrying the full complement of virulence factors were rare in the urinary tract of the spinal patients and were not associated with episodes of symptomatic pyelonephritis. It is clear that the neuropathic bladder and the presence of the catheter permits a wide variety of bacterial types to colonize the urinary tract and cause infection of the kidney. The identification of host markers rather than bacterial factors is suggested as a more fruitful approach to the early detection of cases likely to progress to pyelonephritis in this group of patients.

New Biologic Markers in Non-Hodgkin’s Lymphomas

Many of the tumor markers mentioned in this article may seem to be of only research or theoretic interest. However, many of those mentioned are likely to be of great clinical utility in the future. In particular, the strength of these immunohistochemical findings have been compared with standard clinical prognostic features (e.g., stage, age, B symptoms) and have been modeled to show independent prognostic relevance in both intermediate-grade and low-grade lymphomas. Beyond their predictive value, these markers have identified phenotypes that may serve as new therapeutic targets: (1) restoration of HLA loss with alpha and gamma interferons; and (2) restoration of tumor-infiltrating T-cell lymphocytes with interleukin-2. New phenotype-directed cytokine therapies seem compelling with this new knowledge. We await future prospective trials of phenotyping to further refine this new exciting prospect.

Host-marking pheromones in lepidoptera, with special reference to twoPieris spp

Adult females of several lepidopteran species avoid oviposition near conspecific eggs. Laboratory and field studies indicate that visual factors as well as chemical host markers may be involved in egg avoidance behavior. The oviposition-deterring pheromones (ODP) of two pierids,P. brassicae andP. rapae have been studied in considerable detail. The ODPs are probably produced in the female accessory glands and contain volatile and nonvolatile components. They are perceived by nonspecialized antennal or tarsal receptors, respectively. The ODP ofP. brassicae affects oviposition ofP. rapae females and vice versa. ODPs show promise for insect control programs, but more information on oviposition behavior in the presence of ODP under field conditions is required.

Fasciola hepatica:Sp2/0 (helminth:myeloma) hybridoma expressing parasite antigen.

Cells from adult Fasciola hepatica were fused with cells from a murine BALB/c myeloma Sp2 line. The hybrid cells were grown in HAT (hypoxanthine, aminopterin, and thymidine) medium, cloned and subcloned, and shown to express parasite antigen for 1 year after fusion. Expression of parasite antigen was demonstrated by the following: 2 histogram flow cytometric analyses, in which a population of hybrid cells in the population of 7 month cultured hybrid cells showed 57% more fluorescence when treated with an anti-F. hepatica serum followed by anti-rabbit immunoglobulin G coupled to fluorescein isothiocyanate as compared with the same hybrid cells washed and treated with normal rabbit serum; Sp2 myeloma cells treated with an anti-F. hepatica serum or normal rabbit serum followed by fluorescein-labeled anti-rabbit IgG had the same negative fluorescence; BALB/c mice immunized with PBS-washed cells from a subclone of these hybridomas developed anti-F. hepatica antibodies (shown by the Falcon assay screening test enzyme-linked immunosorbent assay); and antibodies recognized an F. hepatica antigenic polypeptide of 57,000 Mr in a Western immunoblot. These helminth:myeloma hybrids expressed murine host markers, further confirming the hybrid nature of this cell line. F. hepatica cells alone, like their Sp2 fusion partners, die in HAT supplemented medium by 9 days of culture. F. hepatica:Sp2 hybridomas have been grown continuously in HAT medium for greater than 1 year.

An unusual case of mosaic Down's syndrome involving two different Robertsonian translocations.

A baby girl with some of the stigmata of Down's syndrome was found to be a mosaic with three different cell lines: 45,XX,-13,-21,+t(13q21q)/(46,XX/46,XX, -21,+t(21q21q). The chromosome rearrangements detected in this patient appear to have arisen de novo. In the normal cell line the terminal end of the p arm of one chromosome 21 is thought to have been damaged. It seems probable that this is related to the other chromosomal anomalies found.

Recovered src genes are polymorphic and contain host markers

Analysis of recovered sarcoma viruses (rASV) and their parental sarcoma virus SR-D by oligonucleotide fingerprinting revealed multiple differences in the src region of the viral genomes. This heterogeneity was further investigated by tryptic peptide mapping of the in vitro translated products of rASV and SR-D RNA. No differences were found in the pr76 gag proteins encoded by the various rASVs or SR-D, but the p60 src proteins showed considerable variation. The p60 src proteins of rASV could be distinguished from that of SR-D on the basis of their mobility in SDS-polyacrylamide gels. Furthermore, two peptides which were absent from SR-D but consistently found in rASV p60 src proteins were also demonstrated in a tryptic peptide map of the cellular src-related protein, p60 sarc . These results provide strong support for the hypothesis that rASV arose by recombination of residual viral src sequences with cellular src-related sequences.

Transduction by bacteriophage MU-1.

Lysates of bacteriophage Mu are capable of the general transduction of many host markers at frequencies of 10−7 to 10−8 transductants per plaque-forming phage. The transduction is due to the Mu particles in the lysate since it is eliminated by using a Mu resistant recipient strain or by treating the lysate with anti-Mu serum. The transduction frequency is constant over a wide range of phage multiplicities in both Mu sensitive and Mu lysogenic recipients, and transduction is independent of lysogenization by plaque-forming phage. Cotransduction of closely linked markers and abortive transduction have also been observed. Transduction does not occur in a recombination deficient recipient or in a recipient which has a very large deletion of the region to be transduced; thus, it appears that transducing DNA is substituted for host DNA by a host recombination system. The transducing ability cannot be propagated and is lost during one cycle of growth in the recipient. Attempts at the isolation of special transducing particles of Mu carrying leu, trp, and lac have not been successful.

Orientation of prophage Mu.

The temperate bacteriophage Mu can integrate into the chromosome of Escherichia coli in opposite orientations. Both orientations are frequent among Mu insertions in the lacZ gene. The method for determining the prophage orientation described here can be used to orient a Mu prophage located at any site on the host chromosome and to produce F’ strains that transfer host markers in either direction from any location on the genome of E. coli.

Genetic mapping of prophage Mu

The gene order of several independently isolated Mu prophages has been determined by deletion mapping. The prophages in which deletions were produced were located in the lacI gene, the lacZ gene, and the trp operon of Escherichia coli. The Mu deletions were tested for marker rescue against a set of sixteen Mu amber mutants. Marker rescue tests were done by constructing strains lysogenic for both cryptic Mu prophages and Mu amber mutants and then examining the resulting heterogenotes, partially diploid for Mu, for spontaneous production of wild-type Mu particles. The gene order of all Mu prophages was identical, although prophages were found in either of the two orientations with respect to the host markers. It can be inferred therefore that the temperate bacteriophage Mu, which inserts randomly into the chromosome of E. coli, uses a specific site on its own DNA for integration.

Genetic exchanges within prophage φ80 correlated with exchanges between host markers on either side

Four mutations of phage φ80 were mapped in phage crosses in the order am32 — am2 — h- c40. In prophage crosses the same markers were mapped in the order c40 — am32 — am2 — h indicating cyclic permutation as specified by the Campbell model. Genetic exchanges between prophage markers were correlated with exchanges between bacterial markers on either side in quantitative agreement with expectations based on a linearly inserted prophage.

Fate of recipient deoxyribonucleic acid during transformation in Haemophilus influenzae.

During genetic transformation of Haemophilus influenzae, segments of the host deoxyribonucleic acid (DNA) corresponding to the integrating donor DNA were degraded and liberated into the medium. This degradation was detected by the release of the radioactive label from host DNA during a time period matching the time of development of maximal linkage between donor and host markers. The host label released above that released from nontransformed, control cultures was equivalent to about 2% of the host genome or 16 x 10(6) daltons of DNA. The released, labeled material was acid-soluble and dialyzable. The label release from control cultures was unaffected at 30 C; at this temperature, the recombination-specific release from transformed cells was suppressed. High molecular weight fragments of host DNA corresponding in size to the donor fragments could not be found free within the cell, weakly bound to other host DNA, or bound to non-integrated donor DNA by a reciprocal cross mechanism.