Applications of in situ hybridization

In-situ Hybridization for the Detection of Sacbrood Virus in Infected Larvae of the Honey Bee (Apis cerana)

The aim of this study was to develop and use in-situ hybridization (ISH) for the detection and localization of the sacbrood virus (SBV) in Korean honey bee (Apis cerana) larvae that were infected naturally with SBV. A 258 base pair cDNA probe for SBV was generated by polymerase chain reaction. Cells positive for viral genome typically showed a dark brown reaction in the cytoplasm. SBV was detected consistently in trophocytes and urocytes. The ISH was successfully applied to routinely fixed and processed tissues and thus should prove helpful in the diagnosis and characterization of viral distribution in infected larvae.

Immune profile and Epstein-Barr virus infection in acute interstitial nephritis: an immunohistochemical study in 78 patients

BACKGROUND

Acute interstitial nephritis (AIN) is a common cause of acute kidney injury and is characterised by a dense interstitial cellular infiltrate, which has not been well defined. Previous studies have demonstrated a correlation between Epstein-Barr virus (EBV) infection and AIN. The purpose of our study was to define the nature of the interstitial immune infiltrate and to investigate the possibility of renal infection with EBV.

METHODS

Seventy-eight patients with AIN were identified from renal biopsy reports in a single centre over an 18-year period. Immunohistochemical staining was performed to define the cellular infiltrate. In situ hybridization and immunohistology were used to detect EBV.

RESULTS

A positive correlation between CD68 macrophage infiltration and serum creatinine concentration at presentation was identified. IL-4, eotaxin, CCR3, CCR5 and VCAM-1 were all expressed in biopsies of AIN. Using in situ hybridization and immunohistochemistry, EBV was not detected in any of the AIN sections analysed.

CONCLUSION

This study has assessed the nature of the interstitial infiltrate in AIN. EBV was not detected in the renal biopsies, suggesting that EBV is not a pathogenetic factor in AIN.

Optimal probe size and fixation time for the detection of Porcine circovirus-2 DNA by in situ hybridization in formalin-fixed, paraffin-embedded tissue

Probe size and fixation time for detecting Porcine circovirus-2 (PCV-2) by in situ hybridization in formalin-fixed, paraffin-embedded lymph nodes from experimentally infected pigs were optimized. In situ hybridization using a 169-base pair (bp) probe detected significantly fewer PCV-2-positive cells than when using 8 other larger probes (P < 0.05). The difference in hybridization intensity between smaller probes (169 and 225 bp) and larger probes (416, 473, 571, 631, 693, and 753 bp) was statistically significant (P < 0.05). The PCV-2-positive cells were consistently detected in lymph nodes fixed up to 3 days; thereafter, the number of positive cells declined. The PCV-2-positive cells were detected in lymph nodes fixed for up to 730 days. The difference in hybridization intensity between samples fixed for a short term (1 or 3 days) and a longer term (4-730 days) was statistically significant (P < 0.05). The data demonstrates that the optimal probe size and fixation time for detecting PCV-2 in formalin-fixed, paraffin-embedded lymph nodes is 473 bp and 1-3 days, respectively.

Epstein-Barr virus (EBV) in infectious mononucleosis: detection of the virus in tonsillar B lymphocytes but not in desquamated oropharyngeal epithelial cells

AIMS

Despite its well established tropism for B cells, the nature of the cellular compartment(s) mediating primary and persistent Epstein-Barr virus (EBV) infection is still a matter of controversy. In view of the association of EBV with several lymphoid and epithelial malignancies, resolution of this issue is important.

METHODS

Desquamated oropharyngeal epithelial cells from 10 patients with acute infectious mononucleosis and from seven chronic virus carriers were studied for evidence of EBV infection using in situ hybridisation for the detection of the small EBV encoded RNAs (EBERs) and of the viral genome. In addition, immunocytochemistry was used to detect the BZLF1 transactivator protein of EBV.

RESULTS

There was no evidence of latent or replicative EBV infection in oropharyngeal epithelial cells in any of the samples. In contrast, EBV infected B cells were readily identified in a tonsil from a patient with infectious mononucleosis.

CONCLUSIONS

The results suggest that oropharyngeal epithelial cells are not a major site of EBV infection and provide further support for the notion that B cells mediate primary and persistent EBV infection.

Human papillomavirus infection is not associated with bronchial carcinoma: evaluation by in situ hybridization and the polymerase chain reaction

While a strong association between human papillomaviruses (HPVs) and squamous cell cancers of the female genital tract is known to exist, there is substantial controversy regarding the relationship of HPV with other non-genital carcinomas. Recently there have been some reports focusing on a possible association of HPVs with bronchial carcinomas. These studies mostly used either in situ hybridization (ISH) or the polymerase chain reaction (PCR). In view of these reports, 32 squamous cell carcinomas (SCCs) and six small cell carcinomas of the bronchus were examined for the presence of HPV DNA by both techniques: ISH using 35S-labelled, type-specific probes (HPV 6, 11, 16, 18), and PCR with consensus primers coding for more than 25 different HPV subtypes performed on formalin-fixed, paraffin-embedded material. None of the 38 bronchial carcinomas analysed was positive for HPV DNA, either by ISH or by PCR. On the other hand, additionally examined specimens of 15 cervical carcinomas were positive for HPV 16 DNA in at least three cases by ISH (20 per cent) and in 12 cases by PCR (80 per cent). We conclude that common HPV types do not play an important role in the pathogenesis of bronchial carcinoma.

Epstein-Barr virus and carcinomas

The Epstein-Barr virus, a human B lymphotropic herpes virus, is strongly associated with undifferentiated nasopharyngeal carcinoma, which is endemic in Southern China and North Africa. More recently, an association of the virus with certain other epithelial malignancies has been described, some of which are more common in Western countries. Also, the observation that oral hairy leukoplakia, an acquired immunodeficiency syndrome-related lesion of the tongue, supports Epstein-Barr virus replication in the epithelial cell compartment has further strengthened the notion that Epstein-Barr virus infection of epithelial cells may be an important phenomenon in vivo. The purpose of this article is to review the association of Epstein-Barr virus with nasopharyngeal carcinomas, to examine the evidence suggesting an association of the virus with other epithelial neoplasias and to discuss Epstein-Barr virus infection of non-neoplastic epithelial cells.

Software for quantitative immunogold and in situ hybridization

A well-deserved criticism of stereology is that it is often too difficult to understand and use. Nevertheless, it is rapidly becoming one of the most effective ways of collecting and interpreting structural data in experimental biology. Recent breakthroughs in theory have produced a remarkable set of tools that can be used to engineer new methods. The dilemma remains, however, in that some of these new methods continue to be too difficult to understand and use. One solution to this growing problem of technology transfer might be to simplify the methods with computer software. To test this idea, programs were written for quantitative immunogold and in situ hybridization. Simulators were used to develop and test new experimental designs, which, in turn, were translated into step-by-step laboratory tool kits. This paper shows how these tool kits can turn two-dimensional section data into estimates for the number of labeled molecules in three-dimensional organelles, cells, tissues, and organs. The results indicate that software can identify the key data of an experiment and reduce the computational requirements of a new stereological method to entering constants and variables into data entry forms.

An assessment of the efficacy of in situ hybridization as a quantitative method by variance components estimation

One serviceable feature of in situ hybridization is its potential for assessing relative levels of mRNA in specific regions of tissues and organs. To determine its efficacy as a quantitative technique, we applied a nested factorial design to a multifactorial experiment. Estimates of the magnitude of variance components then allowed an assessment of variation over samples of sections from the same tissue source, variation in label over 2 anatomical sites within the same section of tissue, as well as experiment-to-experiment variation. We found approximately 51% of the total variance arose from experiment-to-experiment variation, while approximately 21% of the total variance was due to variation in autoradiography grain density over neurons in the same brain region. Rat-to-rat variation accounted for approximately 11%. About 10% of the variance was due to variation between sections of tissue that were derived from the same tissue source and were hybridized in the same hybridization experiment. Variation between 2 homologous, bilaterally located brain regions located on the same tissue section (the right and left supraoptic nucleus), accounted for approximately 5% of the total variance. The remaining unaccounted error variance was approximately 2% of the total variance. Since an expected change in cellular content of a particular mRNA was observed as a function of experimental treatment, results suggest in situ hybridization is a useful quantitative method.(ABSTRACT TRUNCATED AT 250 WORDS)