Type 1 and type 2 tumor infiltrating effector cell subpopulations in progressive breast cancer

Effector T cells fall into two subpopulations based on cytokine-secretion. Type 1 cells secrete IFN-gamma, whereas type 2 cells secrete IL-4, IL-10, and GM-CSF. NKT cells represent a third subpopulation that secretes similar cytokines and have been associated with immunoregulation. Using the TS/A adenocarcinoma, we assessed the phenotype and kinetics of tumor-infiltrating lymphocytes (TIL) in mice challenged subcutaneously in the mammary region. Flow cytometric analysis shows that T cells do not infiltrate the primary tumor site until days 7-14 following tumor challenge. Both CD4 and CD8 TILs were predominantly CD44(High) and expressed CD25, CD69, and CD95 cell surface activation markers. Activated CD4/CD44(High) TIL numbers reached peak levels at day 21 that precipitously decreased by day 28 whereas corresponding CD8 cell numbers progressively increased, however, at lower levels and with later kinetics. Intracellular cytokine staining showed that greater numbers of IL-4-producing Th2 cells were elicited and with earlier kinetics than that of IFN-gamma-producing Th1 cells. T cells co-expressing DX5 (CD3(+)/DX5(+)) emerged (>21 days), suggesting a recruitment of NK-like T cells at later stages of tumor progression. Moreover, tumors selectively up-regulated TGF-beta, MIF, and IP-10 gene expression at times as early as day 4, with peak levels at day 7 in vivo. Such gene expression remained elevated and correlated with a continued progression in tumor growth suggesting that preferential effector cell recruitment and production of select factors during different stages of tumor maturation may aid in regulating effective endogenous antitumor responses in progressive breast cancer.     

Mast cell tryptase may modulate endothelial cell phenotype in healing myocardial infarcts

Mast cells and macrophages infiltrate healing myocardial infarcts and may play an important role in regulating fibrous tissue deposition and extracellular matrix remodelling. This study examined the time-course of macrophage and mast cell accumulation in healing infarcts and studied the histological characteristics and protease expression profile of mast cells in a canine model of experimental infarction. Although macrophages were more numerous than mast cells in infarct granulation tissue, macrophage density decreased during maturation of the scar, whereas mast cell numbers remained persistently elevated. During the inflammatory phase of infarction, newly recruited leucocytes infiltrated the injured myocardium and appeared to be clustered in close proximity to degranulating cardiac mast cells. During the proliferative phase of healing, mast cells had decreased granular content and were localized close to infarct neovessels. In contrast, macrophages showed no selective localization. Mast cells in healing canine infarcts were alcian blue/safranin-positive cells that expressed both tryptase and chymase. In order to explain the pro-inflammatory and angiogenic actions of tryptase--the major secretory protein of mast cells--its effects on endothelial chemokine expression were examined. Chemokines are chemotactic cytokines that play an important role in leucocyte trafficking and angiogenesis and are highly induced in infarcts. Tryptase, a proteinase-activated receptor (PAR)-2 agonist, induced endothelial expression of the angiogenic chemokines CCL2/MCP-1 and CXCL8/IL-8, but not the angiostatic chemokine CXCL10/IP-10. Endothelial PAR-2 stimulation with the agonist peptide SLIGKV induced a similar chemokine expression profile. Mast cell tryptase may exert its angiogenic effects in part through selective stimulation of angiogenic chemokines.     

Experimental determination of the dosimetric characteristics for the I-Plant model 3600 125I brachytherapy source

The dosimetric characteristics for a new brachytherapy seed source (I-Plant model 3600) were measured using LiF thermoluminescent dosimeters and appropriate phantom materials in conformance with the methodology and guidance provided by the AAPM Task Group 43. The I-Plant model 3600 is the successor to the I-Plant model 3500. The major difference between these sources is that the model 3600 contains a leaded-glass core to provide radio-opacity (while the model 3500 contains a silver core), which does not produce spectral contamination upon neutron activation. The dose rate constant lambda for the model 3600 was determined to be 1.00 Gy h(-1) U(-1) (with a 6% overall relative standard deviation), compared to 1.01 cGy h(-1) U(-1) reported for the model 3500 in previous studies. The remaining dosimetric characteristics also are similar for both sources.     

The potato virus X TGBp2 protein association with the endoplasmic reticulum plays a role in but is not sufficient for viral cell-to-cell movement

Potato virus X (PVX) TGBp1, TGBp2, TGBp3, and coat protein are required for virus cell-to-cell movement. Plasmids expressing GFP fused to TGBp2 were bombarded to leaf epidermal cells and GFP:TGBp2 moved cell to cell in Nicotiana benthamiana leaves but not in Nicotiana tabacum leaves. GFP:TGBp2 movement was observed in TGBp1-transgenic N. tabacum, indicating that TGBp2 requires TGBp1 to promote its movement in N. tabacum. In this study, GFP:TGBp2 was detected in a polygonal pattern that resembles the endoplasmic reticulum (ER) network. Amino acid sequence analysis revealed TGBp2 has two putative transmembrane domains. Two mutations separately introduced into the coding sequences encompassing the putative transmembrane domains within the GFP:TGBp2 plasmids and PVX genome, disrupted membrane binding of GFP:TGBp2, inhibited GFP:TGBp2 movement in N. benthamiana and TGBp1-expressing N. tabacum, and inhibited PVX movement. A third mutation, lying outside the transmembrane domains, had no effect on GFP:TGBp2 ER association or movement in N. benthamiana but inhibited GFP:TGBp2 movement in TGBp1-expressing N. tabacum and PVX movement in either Nicotiana species. Thus, ER association of TGBp2 may be required but not be sufficient for virus movement. TGBp2 likely provides an activity for PVX movement beyond ER association.     

Stress, coping, and hepatitis B antibody status

OBJECTIVE: The present study investigated the association between exposure to stressful life events, coping style, and antibody status after hepatitis B vaccination. METHODS: Two hundred sixty medical school undergraduates, who had received the three-dose hepatitis B vaccine before recruitment to this study, completed questionnaires measuring exposure to stressful life events during the past year, customary coping strategies, and health behaviors. Antibodies against hepatitis B surface antigen were determined; levels <100 mIU/ml were deemed inadequate. RESULTS: Two participant cohorts were identified: those vaccinated within the last year and those vaccinated earlier. In the early vaccination cohort, participants with greater-than-average stress exposures had a more than two-fold increased risk of having an inadequate antibody titer. Coping by accepting the reality of stressful situations proved protective, whereas coping by substance use increased the risk of having an inadequate antibody count in this cohort. These associations remained significant after adjustment for possible mediators. Furthermore, the effects of stress and coping were largely independent of one another. Neither stress nor coping was significantly associated with antibody status in the recently vaccinated cohort. CONCLUSIONS: The present study confirms that the immune system is sensitive to variations in psychological factors. Stressful life events and coping strategy seem to have a continuing impact on hepatitis B antibody status.     

The involvement of CD14 in stimulation of cytokine production by uronic acid polymers

In this study the molecular mechanisms behind the stimulatory activities of the uronic acid polymers poly mannuronic acid (poly M), high M alginate and oxidized cellulose (C60XY) were investigated and compared with lipopolysaccharide (LPS). The cytokine-inducing abilities of the uronic acid polymers and LPS were examined on CD14-positive human monocytes and CD14-negative U373 astrocytoma cells. It was found that LPS induced monocytes and U373 cells to produce tumor necrosis factor (TNF) and interleukin(IL)-6, respectively, by different mechanisms. The poly uronic acids induced monocytes to produce TNF, but with 100-1000 times less potency compared to LPS. On U373 cells, LPS at concentrations ? 32 ng/ml resulted in a dose-related IL-6 production, whereas the poly uronic acids had negligible effects even at 1 mg/ml. The binding data demonstrate that only the CD14-positive monocytes in the peripheral blood mononuclear cells population bound poly M. Furthermore, poly M was found to bind to CD14 in the presence of serum. Antibodies against CD14 also inhibited the TNF-inducing activity of the three uronic acid polymers tested. In conclusion, these results demonstrate that uronic acid polymers induce TNF production through mechanisms which involve CD 14.     

DNA fingerprints in physical anthropology

Hypervariabal minisatellite DNA is a recently described class of nuclear sequences with no known biological function. The minisatellites do form a subtype of restricition fragment length polymorphisms possessing several characteristics particularly intriguing to anthropologists interested in forensics, sociobiology, primate conservation, genetic variability, and molecular evolution. The sequence occupy at least five dozen loci scattered throughout the human genome. Unlike many polymorphisms, many of the loci have numerous alleles each present at similar frequencies. Such a genetic structure produces exceptionally high levels of heterozygosity and thus provides a tool for the individualization of tissue samples. Additionally, as the alleles are inherited in a Mendelian fashion, the minisatellites provide a superb tool for the identification of paternity (or maternity). Unlike standard blood groups, levels of variability are so high in populations studied to data that parentage can be established by inclusion rather than exclution. Homologous sequences are shown to exist in a variety of Old World primates. Visualization of genetic fingerprints in nonhumans may allow for determination of paternity where the pool of potential sires is available, while also providing information on levels of genetic variability. These capabilities will ultimately provide for better management of primate colonies. Used in concert with behavioral data, a number of sociobiological will also become more amenable to investigation.     

Daily versus thrice-weekly interferon alfa-2b plus ribavirin for the treatment of chronic hepatitis C in HIV-infected persons: a multicenter randomized controlled trial

Among HIV-infected persons, chronic hepatitis C virus (HCV) infection causes substantial morbidity and mortality. However, few studies have evaluated the safety and efficacy of interferon alfa (IFN) and ribavirin (RBV) therapy in co-infected persons. Accordingly, a randomized, controlled, open-label, multicenter trial was conducted to establish the safety, tolerability, and efficacy of IFN alfa-2b 3 mIU daily plus RBV 800 mg/d compared with IFN alfa-2b 3 mIU thrice weekly (TIW) plus RBV 800 mg/d in HCV treatment-naive, HIV-infected subjects with compensated liver disease and stable HIV disease. The primary endpoint was sustained virologic response (SVR), defined as an undetectable HCV RNA level 24 weeks after discontinuation of HCV therapy. At study entry, subjects in both groups were similar with respect to age, gender, HCV genotype, and HIV disease status. Of 180 randomized subjects, 162 received at least 1 dose of study medication, constituting the modified intention-to-treat population. After 12 weeks of therapy, 122 (75%) had serum HCV RNA levels assessed; of these subjects, early virologic response (undetectable HCV RNA or >2 log10 decrease from baseline) was observed in 33 (42%) and 13 (16%) of subjects taking daily and TIW IFN, respectively (P < 0.001). SVR was observed in 15 (19.0%) and 7 (8.4%) of subjects taking daily and TIW IFN, respectively (P = 0.05). Adverse events were similar in both groups. However, while no deaths or opportunistic infections were observed, nearly 30% of subjects stopped treatment due to adverse events and 7 subjects experienced a serious adverse event. In conclusion, SVR was achieved in 19% of HIV/HCV coinfected subjects treated with daily IFN plus RBV, but the effectiveness of therapy was substantially diminished by relatively high rates of treatment-related toxicity.