Improvement of supersensitive immunohistochemistry with an autostainer: a simplified catalysed signal amplification system

Molecular correlates and prognostic value of tmTNF-α expression in colorectal cancer of 5-Fluorouracil-Based Adjuvant Therapy

Transmembrane tumor necrosis factor-α (tmTNF-α) is known to induce the activation of NF-κB to protect tumor cells. Upregulation of tmTNF-α leads to resistance to apoptosis and induces drug resistance in breast cancer. However, the expression of tmTNF-α in colorectal cancer (CRC) and its association with clinical outcome in CRC have remained unclear. In this study, we examined the tmTNF-α expression in CRC by immunohistochemistry and western blotting, assessed the prognostic value of tmTNF-α related to the recurrence/metastasis and survival of stage II/III CRC by the Kaplan-Meier survival curve and Cox regression model, and also explored the role of tmTNF-α expression on the chemotherapeutic efficacy of 5-Fluorouracil by flow cytometry assay and cell counting kit-8 (CCK-8) in vitro. Overall, we found that 77 (78.6%) out of 98 patients exhibited higher tmTNF-α expression in the CRC tissues comparing with the adjacent tissues. The tmTNF-α expression was correlated with Differentiation (P = 0.019), TNM stage (P = 0.039), Lymph nodes metastasis (P = 0.024) and Lymphovascular invasion (P = 0.027) but not related with Age (P = 0.617), Gender (P = 0.625), Tumor location (P = 0.138), Perforation/Obstruction (P = 1.000), Depth of invasion (P = 0.327), and microsatellite instability status (P = 0.150). The prognostic analyses showed that high tmTNF-α expression patients was significantly associated with decreased Disease-Free Survival (P = 0.0209) and Overall Survival (P = 0.0163). CCK-8 results suggested that the tmTNF-α influenced the chemotherapeutic effect of 5-Fluorouracil on colon cancer cells. Altogether, these data indicated the stageII/III CRC patients with high tmTNF-α expression were more likely to have a worse prognosis than patients with low tmTNF-α expression and tmTNF-α may influence the chemotherapeutic effect of 5-Fluorouracil. The mechanism for these observations warrants further study.

When tissue antigens and antibodies get along: revisiting the technical aspects of immunohistochemistry--the red, brown, and blue technique

Once focused mainly on the characterization of neoplasms, immunohistochemistry (IHC) today is used in the investigation of a broad range of disease processes with applications in diagnosis, prognostication, therapeutic decisions to tailor treatment to an individual patient, and investigations into the pathogenesis of disease. This review addresses the technical aspects of immunohistochemistry (and, to a lesser extent, immunocytochemistry) with attention to the antigen-antibody reaction, optimal fixation techniques, tissue processing considerations, antigen retrieval methods, detection systems, selection and use of an autostainer, standardization and validation of IHC tests, preparation of proper tissue and reagent controls, tissue microarrays and other high-throughput systems, quality assurance/quality control measures, interpretation of the IHC reaction, and reporting of results. It is now more important than ever, with these sophisticated applications, to standardize the entire IHC process from tissue collection through interpretation and reporting to minimize variability among laboratories and to facilitate quantification and interlaboratory comparison of IHC results.

Development of ultra-super sensitive immunohistochemistry and its application to the etiological study of adult T-cell leukemia/lymphoma

Antigen retrieval (AR) and ultra-super sensitive immunohistochemistry (ultra-IHC) have been established for application to archival human pathology specimens. The original ultra-IHC was the ImmunoMax method or the catalyzed signal amplification system (ImmunoMax/CSA method), comprising the streptavidin-biotin complex (sABC) method and catalyzed reporter deposition (CARD) reaction with visualization of its deposition. By introducing procedures to diminish non-specific staining in the original ultra-IHC method, we developed the modified ImmunoMax/CSA method with AR heating sections in an AR solution (heating-AR). The heating-AR and modified ImmunoMax/CSA method visualized expression of the predominantly simple present form of HTLV-1 proviral DNA pX region p40Tax protein (Tax) in adult T-cell leukemia/lymphoma (ATLL) cells in archival pathology specimens in approximately 75% of cases. The simple present form of Tax detected exhibited a close relation with ATLL cell proliferation. We also established a new simplified CSA (nsCSA) system by replacing the sABC method with the secondary antibody- and horse radish peroxidase-labeled polymer reagent method, introducing the pretreatments blocking non-specific binding of secondary antibody reagent, and diminishing the diffusion of deposition in the CARD reaction. Combined with AR treating sections with proteinase K solution (enzymatic-AR), the nsCSA system visualized granular immunostaining of the complex present form of Tax in a small number of ATLL cells in most cases, presenting the possibility of etiological pathological diagnosis of ATLL and suggesting that the complex present form of Tax-positive ATLL cells were young cells derived from ATLL stem cells. The heating-AR and ultra-IHC detected physiological expression of the p53 protein and its probable phosphorylation by Tax in peripheral blood mononuclear cells of peripheral blood tissue specimens from HTLV-1 carriers, as well as physiological and pathological expression of the molecules involved with G1 phase progression and G1–S phase transition (E2F-1, E2F-4, DP-1, and cyclin E) in ATLL and peripheral T-cell lymphoma cells. The ultra-IHC with AR is useful for etiological pathological diagnosis of ATLL since HTLV-1 pathogenicity depends on that of Tax, and can be a useful tool for studies translating advanced molecular biology and pathology to human pathology.

Homeostatic mass control in gastric non-neoplastic epithelia under infection of Helicobacter pylori: an immunohistochemical analysis of cell growth, stem cells and programmed cell death

We evaluated homeostatic mass control in non-neoplastic gastric epithelia under Helicobacter pylori (HP) infection in the macroscopically normal-appearing mucosa resected from the stomach with gastric cancer, immunohistochemically analyzing the proliferation, kinetics of stem cells and programmed cell death occurring in them. Ki67 antigen-positive proliferating cells were found dominantly in the elongated neck portion, sparsely in the fundic areas and sporadically in the stroma with chronic infiltrates. CD117 could monitor the kinetics of gastric stem cells and showed its expression in two stages of gastric epithelial differentiation, namely, in transient cells from the gastric epithelial stem cells to the foveolar and glandular cells in the neck portion and in what are apparently progenitor cells from the gastric stem cells in the stroma among the infiltrates. Most of the nuclei were positive for ssDNA in the almost normal mucosa, suggesting DNA damage. Cleaved caspase-3-positive foveolar cells were noted under the surface, suggesting the suppression of apoptosis in the surface foveolar cells. Besides such apoptosis of the foveolar cells, in the severely inflamed mucosa apoptotic cells were found in the neck portion where most of the cells were Ki67 antigen-positive proliferating cells. Beclin-1 was recognized in the cytoplasm and in a few nuclei of the fundic glandular cells, suggesting their autophagic cell death and mutated beclin-1 in the nuclei. Taken together, the direct and indirect effects of HP infection on the gastric epithelial proliferation, differentiation and programmed cell death suggested the in-situ occurrence of gastric cancer under HP infection.

A simplified, sensitive immunohistochemical detection system employing signal amplification based on fluorescyl-tyramide/antifluorescein antibody reaction: its application to pathologic testing and research

The catalyzed signal amplification (CSA) technique, based on the peroxidase-mediated deposition of haptenized tyramide and also known as tyramide signal amplification and catalyzed reportor deposition systems, is widely accepted as a signal amplification method for immunohistochemistry and in situ hybridization. In this study, we examined the applicability of a new simplified CSA system employing fluorescyl-tyramide (FT) to pathologic testing and research with formalin-fixed, paraffin-embedded tissues. By using the FT, instead of biotinyl-tyramide (BT) that is commonly employed in the CSA system with chromogen, nonspecific staining caused by endogenous biotin was completely avoided. The FT-CSA system loaded on the automated immunostaining equipment also allowed for more reproducible detection in short times. When applied to cyclin D1 immunostaining that is important in differentiation among small B-cell lymphomas, the system was useful in demonstrating its protein expression in mantle cell lymphomas considered negative or equivocally positive for cyclin D1 in a conventional immunodetection. In immunohistochemistry for phosphorylated proteins and murine hematologic markers that often require higher sensitivity than conventional methods, the FT-CSA system provided desirable staining results with intense signal amplification. Our results indicate that the simplified CSA system employing the FT can be useful in enlarging the target range for routine immunohistochemistry due to its high applicability.

Technical aspects of immunohistochemistry

Immunohistochemistry is an integral technique in many veterinary laboratories for diagnostic and research purposes. In the last decade, the ability to detect antigens (Ags) in tissue sections has improved dramatically, mainly by countering the deleterious effects of formaldehyde with antigen retrieval (AR) and increasing sensitivity of the detection systems. In this review, I address these topics and provide an overview of technical aspects of immunohistochemistry, including those related to antibodies (Abs) and Ags, fixation, AR, detection methods, background, and troubleshooting. Microarray technology and the use of rabbit monoclonal Abs in immunohistochemistry are also discussed.

A new simplified catalyzed signal amplification system for minimizing non-specific staining in tissues with supersensitive immunohistochemistry

We investigated non-specific staining in a catalyzed reporter deposition (CARD) reaction and improved its blocking methods in supersensitive immunohistochemistry, based on our simplified catalyzed signal amplification (CSA) system (Hasui et al. 2002). In the CARD reaction using biotinyl tyramide, non-specific staining could be reduced by pretreatment with a casein solution or 3% bovine serum albumin (BSA)-phosphate buffer saline (PBS) with 0.1% Tween 20. In the CARD reaction using FITC-labeled tyramide, non-specific staining could be blocked by pretreatment with 0.3% BSA-PBS with 0.1% Tween 20 or 3% polyethylene glycol-PBS with 01% Tween 20. Thus, our new simplified CSA system features: 1) destruction of the endogenous peroxidase activity; 2) blocking of the nonspecific reaction of the primary antibody; 3) a primary antibody reaction; 4) blocking of the non-specific reaction of the polymer reagent by casein treatment; 5) a polymer reaction; 6) blocking of the non-specific reaction of CARD reaction by casein treatment; 7) a CARD reaction; and 8) detection of deposited tyramide. This new system proved useful for detecting an extremely low amount of antigen in the endogenous biotin-rich tissues such as the gastrointestinal tract and liver. By this method, the Ki67 antigen in the G1 phase cell cycle could be detected and a metabolic disorder of the Ki67 antigen was implicated in a carcinoid tumor in the stomach. We believe that this new simplified CSA system represents a new standard of supersensitive immunohistochemistry for use in light-microscopic investigation.

Altered expression of inflammatory cytokines in primary osteoarthritis by human T lymphotropic virus type I retrovirus infection: a cross-sectional study

Human T cell leukaemia virus type I (HTLV-I) is known to be involved in late-onset chronic polyarthritis as HTLV-I-associated arthropathy. However, it is unclear whether HTLV-I infection could modify the pathophysiology of osteoarthritis (OA). In this study we compared several inflammatory cytokines, such as C-terminal parathyroid hormone-related peptide (C-PTHrP), soluble interleukin-2 receptor (sIL-2R) and interleukin (IL)-6, and an osteo-destruction marker, deoxypyridinoline, in synovial fluid (SF) samples obtained from 22 HTLV-I carriers and 58 control non-carrier patients with OA. These patients were diagnosed clinically and radiographically with primary OA affecting one or both knee joints, and were similar with regard to age, sex and clinical symptoms. We also performed histopathological examination as well as immunohistochemistry of HTLV-I-derived Tax protein in eight synovial tissues taken from carrier patients. C-PTHrP in SF was significantly higher in HTLV-I carriers (287 ± 280 pM) than in non-carriers (69 ± 34 pM), and the concentration in 13 carriers was above the upper range of OA. In HTLV-I carriers, the concentrations of sIL-2R (741 ± 530 IU/ml), IL-6 (55 ± 86 ng/ml) and deoxypyridinoline (3.1 ± 1.8 nM) were higher than in non-carriers (299 ± 303, 2.5 ± 4.0, 0.96 ± 1.0, respectively), and correlated positively with C-PTHrP. C-PTHrP, sIL-2R and IL-6 concentrations in SF positive for IgM antibody against HTLV-I antigen, a marker of persistent viral replication, were higher than of IgM-negative SF. Histologically, five and two synovia showed mild and moderate synovial proliferation with or without some degree of inflammatory reaction, respectively, and could not be distinguished from OA. Tax-positive synoviocytes were observed sparsely in all samples, and often appeared frequently in actively proliferating regions. Our results suggest that although HTLV-I infection does not necessarily worsen the clinical outcome and local synovitis, the virus can potentially modify the pathophysiology of OA by increasing the inflammatory activity in a subset of carrier patients, especially those with IgM antibody. Longitudinal studies are required to assess the association between HTLV-I infection and OA.

Double autoimmunostaining with glycine treatment

Double autoimmunostaining by a sequential twice-repeated enzyme-labeled polymer method was examined on archival paraffin sections of formalin-fixed human tissue using an autoimmunostaining apparatus to determine optimal conditions for glycine treatment, to select the best combination of dyes for the horseradish peroxidase-hydrogen peroxide reaction, and to investigate mounting methods for preparing permanent specimens. The optimal glycine treatment determined by changing the incubation time in 0.1 M glycine hydrochloride buffer, pH 2.2, was glycine buffer washing three times for 1 min each, with suppression of nonspecific binding of the primary antibody by protein blocking. Combinations of DAB and AEC, SG and AEC with Ultramount, and DAB and VIP or NovaRED and SG with the VectaMount were found usable for the double autoimmunostaining, based on color analysis of the dyes. Pairs of primary antibodies, CD68 and anti-fascin antibodies CD3 and CD79a, and anti-Ki-67 antigen and anti-p53 antibodies were applicable in double autoimmunostaining with appropriate antigen retrieval for each pair of primary antibodies. Consequently, good sequential double autoimmunostaining should include masking the nonspecific binding of primary antibodies, optimal glycine treatment, and selection of adequate dyes and mounting methods.