Fate of Entosis: From the Beginning to the End in Untreated Advanced Breast Cancer.

Homotypic entosis is a phenomenon in which one cancer cell invades a neighboring cancer cell and is closed entirely within its entotic vacuole. The fate of entosis can lead to inner cell death or survival. Recent evidence draws attention to entosis as a novel prognostic marker in breast cancer. Nevertheless, little is known about the quantity and quality of the process of entosis in human cancer specimens. Here, for the first time, we analyze the frequency of entotic figures in a case of NOS (Non-Other Specified) breast cancer with regard to location: the primary tumor, regional lymph node, and distant metastasis. For the identification of entotic figures, cells were stained using hematoxylin/eosin and assessed using criteria proposed by Mackay. The majority of entotic figures (65%) were found in the lymph node, 27% were found in the primary tumor, and 8% were found in the far metastasis. In the far metastases, entotic figures demonstrated an altered, atypic morphology. Interestingly, in all locations, entosis did not show any signs of cell death. Moreover, the slides were stained for E-cadherin or Ki67, and we identified proliferating (Ki67-positive) inner and outer entotic cells. Therefore, we propose additional criteria for the identification of pro-survival entotic structures in diagnostic histopathology.

CD4+ T Cells Are Not Required for Suppression of Hepatitis B Virus Replication in the Liver of Vaccinated Chimpanzees.

Humans vaccinated with hepatitis B virus (HBV) surface antigen (HBsAg) sometimes develop humoral and cellular immunity to HBV proteins such as core and polymerase that are not vaccine components, providing indirect evidence that vaccine-induced immunity is not sterilizing. We previously described CD4(+) T-cell immunity against HBsAg and polymerase in chimpanzees after vaccination and HBV challenge. Here, vaccinated chimpanzees with protective levels of anti-HBsAg antibodies were rechallenged with HBV after antibody-mediated CD4(+) T-cell depletion. HBV DNA was detected in liver for at least 3 months after rechallenge, but virus replication was suppressed, as revealed by the absence of HBV DNA and HBsAg in serum. These observations provide direct virological evidence for nonsterilizing immunity in individuals with anti-HBsAg antibodies and are consistent with translation of HBV proteins to prime immune responses. They also indicate that CD4(+) T cells were not required for suppression of HBV replication in previously vaccinated individuals.

Evaluation of calretinin immunohistochemistry as an additional tool in confirming the diagnosis of Hirschsprung disease.

Hirschsprung disease (HD) is a congenital malformation defined as the absence of myenteric and submucosal ganglion cells (GCs) in the distal rectum and variable length of the contiguous bowel. The aim of this study was to assess the utility of calretinin immunochemistry in comparison with that of standard histology complemented with acetylcholinesterase (AChE) histochemistry routinely employed at our institution to evaluate rectal biopsies carried out for suspicion of HD. Twenty-one rectal biopsies were reviewed, including 14 from patients with suspected HD, 6 from infants with necrotizing enterocolitis (NEC), and 1 from a patient diagnosed with spontaneous intestinal perforation (SIP). Sections stained with hematoxylin-eosin (HE) revealed absence of ganglion cells in 13 cases which included 11 patients with HD and 2 patients with NEC. Among 13 cases of aganglionosis the AChE reaction pattern was consistent with HD in 2 patients. Calretinin positivity was observed in all rectal biopsies showing the presence of GC, and the staining was consistently absent in all cases of aganglionosis. In 6 rectal biopsies in which abnormal acetylcholinesterase (AChE) staining was not seen, loss of calretinin immunoreactivity helped establish the diagnosis of HD.

Hepatitis B vaccine immunogenicity among adults vaccinated during an outbreak response in an assisted living facility--Virginia, 2010.

BACKGROUND: Failure to adhere to infection control guidelines, especially during assisted monitoring of blood glucose, has caused multiple hepatitis B outbreaks in assisted living facilities (ALFs). In conjunction with the response to such an outbreak at an ALF ("Facility X") where most residents had neuropsychiatric disorders, we evaluated seroprotection rates conferred by hepatitis B vaccine and assessed the influence of demographic factors on vaccine response. METHODS: Residents were screened for hepatitis B and C infection, and those susceptible were vaccinated against hepatitis A and hepatitis B with one dose of TWINRIX™ (GSK) given at 0, 1, and 7 months. Blood samples were collected 1-2 months after receipt of the third vaccine dose to test for antibody to hepatitis B surface antigen (anti-HBs). RESULTS: Of the 27 residents who had post-vaccination blood specimens collected, 22 (81%) achieved anti-HBs concentrations ≥10 mIU/mL. Neither age nor neuropsychiatric comorbidity was a significant determinant of seroprotection. Geometric mean concentration was lower among residents aged 60-74 years (74.3 mIU/mL) than among residents aged 46-59 years (105.3 mIU/mL) but highest among residents aged ≥75 years (122.5 mIU/mL). The effect of diabetes on vaccination response could not be examined because 16/17 (94%) diabetic residents had HBV infection by the time of investigation. CONCLUSIONS: Adult vaccine recipients of all ages, even those over 60 years of age, demonstrated a robust capacity for achieving hepatitis B seroprotection in response to the combined hepatitis A/hepatitis B vaccine. The role for vaccination in interrupting HBV transmission during an outbreak remains unclear, but concerns about age-related response to hepatitis B vaccine may be insufficient to justify foregoing vaccination of susceptible residents of ALFs.

Immunopathogenesis of hepatitis E virus infection.

The course of hepatitis E virus infection (HEV) can vary substantially between different individuals. Although most infections take a clinically silent asymptomatic course, a few patients may develop severe hepatitis that can progress to fulminant hepatic failure. In addition, cases of chronic hepatitis E have been described in immunosuppressed patients. The detailed mechanisms leading to different clinical outcomes of HEV infection are only partially understood. Both viral factors including the HEV genotype and the dose of the infectious inoculum, as well as host factors such as stage of liver disease, pregnancy or distinct genetic polymorphisms determine the course of HEV infection. Recent studies were able to associate T-cell responses, activation of the interferon system and viral evolution with severity or chronicity of hepatitis E. We here summarize the emerging data on the immunopathogenesis of HEV infection.

Both innate and adaptive immunity mediate protective immunity against hepatitis C virus infection in chimpanzees.

UNLABELLED: Understanding the immunological correlates associated with protective immunity following hepatitis C virus (HCV) reexposure is a prerequisite for the design of effective HCV vaccines and immunotherapeutics. In this study we performed a comprehensive analysis of innate and adaptive immunity following HCV reexposure of two chimpanzees that had previously recovered from HCV-JFH1 infection. One of the chimpanzees, CH10274, became protected from active viremia by repeated challenges with homologous HCV-JFH1 and developed neutralizing antibodies, but was later infected with high-level viremia by a heterologous challenge with the HCV H77 virus that persisted for more than 1 year. The other chimpanzee, CH10273, was protected from a similar, heterologous H77 challenge without any evidence of neutralizing antibodies. Peripheral HCV-specific T-cell responses were present in both chimpanzees after challenges and, interestingly, the overall magnitude of response was lower in uninfected CH10273, which, however, exhibited a more robust CD8+ T-cell response. CH10273 showed higher hepatic expression of CD8 and CD56 (natural killer) markers than CH10274 did shortly after inoculation with H77. The heightened T-cell response was associated with an enhanced hepatic production of interferons (both type I and II) and interferon-stimulated genes (ISGs) in CH10273. Therefore, protection or clearance of HCV reinfection upon heterologous rechallenge depends on the activation of both intrahepatic innate and cellular immune responses. Furthermore, our results suggest that serum neutralizing antibodies may contribute to early control of viral replication and spread after homologous HCV rechallenges but may not be sufficient for a long-term protective immunity. CONCLUSION: Our study shows that protective immunity against HCV reinfection is orchestrated by a complex network of innate and adaptive immune responses.

Pathogenetic elements of hepatitis E and animal models of HEV infection.

The pathogenesis of HEV infection responsible for liver pathology and clinical disease is not well understood. The main target for the virus is the hepatocyte, where it replicates and is released to bile and gastrointestinal tract. Viremia is regularly seen during the virus replication. The exact mechanism of hepatocytic death is uncertain. In experimentally infected non-human primates, the peak of liver lesions, measured by alanine aminotransferase activity elevation, is concordant with the virus disappearance from stool at the time of dynamic humoral immune response; the role of cellular immunity has not been researched adequately, especially HEV-specific immune response in the liver. Non-human primates (chimpanzees, rhesus and cynomolgus macaques) are most widely used animal models for the study of HEV infection, its pathogenesis and vaccine trials. Several other animal models including pigs, rabbits and chickens have recently been established for the study of various aspects of HEV infection. Infectivity studies in susceptible primates were of significance in molecular studies of the virus itself. Preclinical vaccine trials with the use of various recombinant HEV capsid proteins and viral DNA established basic platform for formulation of HEV vaccine applied in HEV-endemic regions (China, Nepal).

Changes in lymphocyte subsets in children with newly diagnosed type 1 diabetes mellitus.

UNLABELLED: The aim of this study was to assess changes in selected peripheral blood lymphocyte subsets in children and adolescents with newly diagnosed type 1 diabetes mellitus (DM) and determine the correlation between these changes and other immunological markers. The study involved a group of 39 patients aged 2-14 years and a control group. The number of T- and B-lymphocytes and the number of CD4, CD8, CD4/HLA-DR, CD8/HLA-DR, CD5/CD20 subsets were measured by flow-cytometry using monoclonal antibodies. Islet cell antibodies (ICA) and antibodies to glutamic acid decarboxylase (GADA) were assessed. In both the diabetic and control groups the number of T-and B-lymphocytes were within normal limits. In patients with DM, the percentage of CD5+/CD20+ cells was significantly increased compared with the control group (p < 0.0001). ICA were positive in 80% of patients and GADA in nearly 65%. A positive correlation between the CD5/CD20 subset and ICA and GADA was found. In patients with a high percentage of CD5+/CD20+ lymphocytes, a higher percentage of activated subsets (CD4/HLA DR and CD8/ HLA DR) was detected. IN CONCLUSION: CD5/ CD20 lymphocyte subsets are a good additional marker of autoimmunological processes in DM.

IL-12 or IL-15, unlike IL-2, does not interact with histamine in augmenting cytotoxicity of splenocytes against melanoma cells and YAC-1 cells.

It has been suggested that histamine by its ability to downregulate the production of macrophage-derived reactive oxygen species might effectively potentiate the cytotoxic activity of cytokine-stimulated NK cells. Histamine thus reverses negative regulation of NK cells treated with IL-2 and IFN-alpha in the presence of macrophages. We confirm that histamine potently enhances cytotoxic activity of IL-2-stimulated NK cell-enriched splenocytes admixed with macrophages against B16F10 melanoma cells and YAC-1 cells. This stimulation results in production of high amounts of INF-gamma and TNF-alpha. Interestingly, IL-15 by itself promotes production of reactive oxygen species. Although histamine decreased reactive oxygen species production from the cultures of IL-15-stimulated NK cell-enriched splenocytes admixed with macrophages, it did not potentiate the cytotoxicity of IL-15. Further, we demonstrate that histamine-mediated potentiation of cytotoxicity is not applicable to IL-12, another potent activator of NK cell activity.