Anti-idiotype antibody induced cellular immunity in mice transgenic for human carcinoembryonic antigen

In the present study, we have analysed the detailed cellular immune mechanisms involved in tumour rejection in carcinoembryonic antigen (CEA) transgenic mice after immunization with dendritic cells (DC) pulsed with an anti-idiotype (Id) antibody, 3H1, which mimics CEA. 3H1-pulsed DC vaccinations resulted in induction of CEA specific cytotoxic T lymphocyte (CTL) responses in vitro and the rejection of CEA-transfected MC-38 murine colon carcinoma cells, C15, in vivo (Saha et al.,Cancer Res 2004; 64: 4995-5003). These CTL mediated major histocompatibility complex (MHC) class I-restricted tumour cell lysis, production of interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha), and expression of Fas ligand (FasL) and TNF-related apoptosis-inducing ligand (TRAIL) in response to C15 cells. CTL used perforin-, FasL-, and TRAIL-mediated death pathways to lyse C15 cells, although perforin-mediated killing was the predominant lytic mechanism in vitro. The cytokines IFN-gamma and TNF-alpha synergistically enhanced surface expression of Fas, TRAIL receptor, MHC class I and class II on C15 cells that increased the sensitivity of tumour cells to CTL lysis. CTL activity generated in 3H1-pulsed DC immunized mice was directed against an epitope defined by the idio-peptide LCD-2, derived from 3H1. In vivo lymphocyte depletion experiments demonstrated that induction of CTL response and antitumour immunity was dependent on both CD4+ and CD8+ T cells. The analysis of splenocytes of immunized mice that had rejected C15 tumour growth revealed up-regulated surface expression of memory phenotype Ly-6C and CD44 on both CD4+ and CD8+ T cells. The adoptive transfer experiments also suggested the role of both CD4+ and CD8+ T cells in this model system. Furthermore, mice that had rejected C15 tumour growth, developed tumour-specific immunological memory.     

Identification of a new genotype H wild-type mumps virus strain and its molecular relatedness to other virulent and attenuated strains

A single clinical isolate of mumps virus designated 88-1961 was obtained from a patient hospitalized with a clinical history of upper respiratory tract infection, parotitis, severe headache, fever and lymphadenopathy. We have sequenced the full-length genome of 88-1961 and compared it against all available full-length sequences of mumps virus. Based upon its nucleotide sequence of the SH gene 88-1961 was identified as a genotype H mumps strain. The overall extent of nucleotide and amino acid differences between each individual gene and protein of 88-1961 and the full-length mumps samples showed that the missense to silent ratios were unevenly distributed. Upon evaluation of the consensus sequence of 88-1961, four positions were found to be clearly heterogeneous at the nucleotide level (NP 315C/T, NP 318C/T, F 271A/C, and HN 855C/T). Sequence analysis revealed that the amino acid sequences for the NP, M, and the L protein were the most conserved, whereas the SH protein exhibited the highest variability among the compared mumps genotypes A, B, and G. No identifying molecular patterns in the non-coding (intergenic) or coding regions of 88-1961 were found when we compared it against relatively virulent (Urabe AM9 B, Glouc1/UK96, 87-1004 and 87-1005) and non-virulent mumps strains (Jeryl Lynn and all Urabe Am9 A substrains).     

A copper chelate selectively triggers apoptosis in myeloid-derived suppressor cells in a drug-resistant tumor model and enhances antitumor immune response

Myeloid-derived suppressor cells (MDSCs), one of the major orchestrators of immunosuppressive network are present in the tumor microenvironment suppress antitumor immunity by subverting Th1 response in tumor site and considered as a great obstacle for advancement of different cancer immunotherapeutic protocols. Till date, various pharmacological approaches have been explored to modulate the suppressive functions of MDSCs in vivo. The present study describes our endeavor to explore a possibility of eradicating MDSCs by the application of a copper chelate, namely copper N-(2-hydroxy acetophenone) glycinate (CuNG), previously found to be a potential immunomodulator that can elicit antitumorogenic Th1 response in doxorubicin-resistant EAC (EAC/Dox) bearing mice. Herein, we demonstrated that CuNG treatment could reduce Gr-1+CD11b+ MDSC accumulation in ascitic fluid and spleen of EAC/Dox tumor model. Furthermore, we found that CuNG mediated reduction in MDSCs is associated with induction of Th1 response and reduction in Treg cells. Moreover, we observed that CuNG could deplete MDSCs by inducing Fas-FasL mediated apoptotic cell death where death receptor Fas expression is enhanced in MDSCs and FasL is provided by activated T cells. However, MDSC expansion from bone marrow cells and their differentiation was not affected by CuNG. Altogether, these findings suggest that the immunomodulatory property of CuNG is attributed to, at least in part, by its selective cytotoxic action on MDSCs. So, this preclinical study unveils a new mechanism of regulating MDSC levels in drug-resistant cancer model and holds promise of translating the findings into clinical settings.     

Fragmented QRS Complex: A Novel Marker of Cardiovascular Disease

QRS complex fragmentation, defined as changes in QRS morphology with different RSR′ patterns: additional R waves, notched S wave, or > 1R′ wave, has recently been linked with various cardiac conditions and even been postulated to be predictive of outcomes in certain pathologies. The current article aims to consolidate the available information about this morphological ECG abnormality and its predictive value. Copyright © 2010 Wiley Periodicals, Inc.     

Zebrafish peptidoglycan recognition proteins are bactericidal amidases essential for defense against bacterial infections

Peptidoglycan recognition proteins (PGRPs) are structurally conserved through evolution, but their functions in innate immunity are different in invertebrates and vertebrates. We asked what the functions of PGRPs in fish are and whether they are indispensable for defense against infection because fish are the first vertebrates that developed adaptive immunity, but they still rely solely on innate immunity during early development of embryos. We identified and cloned three zebrafish PGRPs and showed that they are highly expressed in eggs, developing embryos, and adult tissues that contact external environment. Zebrafish PGRPs have both peptidoglycan-lytic amidase activity and broad-spectrum bactericidal activity, which is a unique feature. Furthermore, we demonstrated that in the developing zebrafish embryo, one of these PGRPs is essential for defense and survival during bacterial infections. These data demonstrate an absolute requirement for innate immunity in defense against infections in fish embryos and for a PGRP protein for survival in vertebrates.     

Infant birthweight in the US: the role of preconception stressful life events and substance use

The purpose of this study was to determine the relationships among preconception stressful life events (PSLEs), women’s alcohol and tobacco use before and during pregnancy, and infant birthweight. Data were from the Early Childhood Longitudinal Study-Birth Cohort (n?=?9,350). Data were collected in 2001. Exposure to PSLEs was defined by indications of death of a parent, spouse, or previous live born child; divorce or marital separation; or fertility problems prior to conception. Survey data determined alcohol and tobacco usage during the 3 months prior to and in the final 3 months of pregnancy. We used staged multivariable logistic regression to estimate the effects of women’s substance use and PSLEs on the risk of having a very low (<1,500 g, VLBW) or low (1,500–2,499 g, LBW) birthweight infant, adjusting for confounders. Women who experienced any PSLE were more likely to give birth to VLBW infants (adjusted odds ratio [AOR]?=?1.35; 95 % confidence interval [CI]?=?1.10–1.66) than women who did not experience any PSLE. Compared to women who never smoked, women who smoked prior to conception (AOR?=?1.31; 95 % CI?=?1.04–1.66) or during their last trimester (AOR?=?1.98; 95 % CI?=?1.56–2.52) were more likely to give birth to LBW infants. PSLEs and women’s tobacco use before and during pregnancy are independent risk factors for having a lower birthweight baby. Interventions to improve birth outcomes may need to address women’s health and health behaviors in the preconception period.     

Mechanisms of nitric oxide interplay with Rho GTPase family members in modulation of actin membrane dynamics in pericytes and fibroblasts

Migration of pericytes such as hepatic stellate cells is fundamentally important for diverse biological and pathological processes including tumor invasion and fibrosis. In prototypical migratory cells such as fibroblasts, the small GTPases Rac1 and RhoA govern the assembly of lamellipodia and stress fibers, respectively, cytoskeletal structures that are integral to the cell migration process. The gaseous signaling molecule nitric oxide (NO) influences growth factor chemotactic responses, although this occurs primarily in cell-type-specific ways and through cell biological effects that are poorly characterized. In this study, we use complementary molecular and cell biological approaches to delineate important roles for Rac1, RhoA, and NO in migration of the human hepatic stellate cell line LX2 and primary rat hepatic stellate cells. Both platelet-derived growth factor (PDGF) and Rac1 overexpression drove migration through formation of actin-positive filopodia spikes in LX2 as compared to the formation of lamellipodia in fibroblasts. NO inhibited PDGF- and Rac1-driven migration in LX2 by abrogating filopodia formation and inhibited migration of fibroblasts by attenuating lamellipodial protrusions. Additionally, RhoA conferred resistance to NO inhibition of migration and restored chemotactic responses to PDGF in the absence of functional Rac1 in LX2. In conclusion, these studies identify novel crosstalk between small GTPases, cytoskeletal structures, and NO in pericyte-specific pathways, providing counterbalances in the chemotactic responses to growth factors.