A Robust Method of Measuring Other-Race and Other-Ethnicity Effects: The Cambridge Face Memory Test Format

Other-race and other-ethnicity effects on face memory have remained a topic of consistent research interest over several decades, across fields including face perception, social psychology, and forensic psychology (eyewitness testimony). Here we demonstrate that the Cambridge Face Memory Test format provides a robust method for measuring these effects. Testing the Cambridge Face Memory Test original version (CFMT-original; European-ancestry faces from Boston USA) and a new Cambridge Face Memory Test Chinese (CFMT-Chinese), with European and Asian observers, we report a race-of-face by race-of-observer interaction that was highly significant despite modest sample size and despite observers who had quite high exposure to the other race. We attribute this to high statistical power arising from the very high internal reliability of the tasks. This power also allows us to demonstrate a much smaller within-race other ethnicity effect, based on differences in European physiognomy between Boston faces/observers and Australian faces/observers (using the CFMT-Australian).     

Novel Translation Products from Simian Immunodeficiency Virus SIVmac239 Env-Encoding mRNA Contain both Rev and Cryptic T-Cell Epitopes

Understanding the correlates of immune protection against human immunodeficiency virus and simian immunodeficiency virus (SIV) will require defining the entire cellular immune response against the viruses. Here, we define two novel translation products from the SIV env mRNA that are targeted by the T-cell response in SIV-infected rhesus macaques. The shorter product is a subset of the larger product, which contains both the first exon of the Rev protein and a translated portion of the rev intron. Our data suggest that the translation of viral alternate reading frames may be an important source of T-cell epitopes, including epitopes normally derived from functional proteins.The pathway from viral infection to the cellular immune response is not well understood. Despite the importance of T-cell responses in control of AIDS virus replication (1, 3, 8, 22), the sources of the peptides recognized by virus-specific T cells are still being discovered. AIDS virus-specific CD8⁺ T lymphocytes (CD8-TL) recognize complexes of major histocompatibility complex (MHC) class I and virus-derived epitopes presented on the surface of infected cells. These epitopes can be derived from exogenous viral proteins in the infecting virion (19, 20) or from de novo synthesis of viral proteins (9, 21). Additional sources of epitopes are also being explored (4, 6).CD8-TL can also recognize epitopes derived from translation of viral alternate reading frames (ARFs). Though CD8-TL specific for ARF-derived epitopes have been detected in human immunodeficiency virus (HIV) (2), they remain a largely unexplored source of epitopes that might elicit potent antiviral cellular immune responses. We recently showed that SIVmac239-infected rhesus macaques that spontaneously controlled viral replication, termed elite controllers, made immunodominant CD8-TL responses against an epitope (RHLAFKCLW, or cRW9) derived from an ARF of the env gene (15). This response selected for viral escape in vivo and suppressed viral replication in an in vitro assay. These findings imply that CD8-TL specific for ARF-derived epitopes might be an important component of the total AIDS virus-specific cellular immune response.Here, we show that the cRW9 epitope is translated as part of two distinct products that differ in size due to start codon usage. The larger and more frequent product contains both the first 23 amino acids of the Rev protein (exon 1) and 50 amino acids translated from the rev intron. The smaller is produced by translation initiation at a start codon within the rev intron and is a subset of the larger product. Finally, we show that these products are degraded after translation from the mature Env-encoding mRNA.     

The role of aminoglycoside--modifying enzymes in resistance of Gram-negative rods

The aim of the study was to evaluate the aminoglycoside resistance of Gram-negative bacilli isolated from patients. To the examination 35 strains of Enterobacteriaceae and 18 of non-fermentative bacteria were included. Resistance to aminoglycosides (gentamicin (G), netilmicin (Nt), tobramycin (T), amikacin (A), kanamycin (K), neomycin (N)) was established by disk diffusion method. Interpretation of enzymatic mechanisms was performed by Livermore. The most common enzymes AAC(6')I were found in Enterobacteriaceae group (mostly in E. cloaceae and P. mirabilis) and AAC(3') and in non-fermentative bacteria: AAC(6')I in P. aeruginosa and APH(3')VI and AAC(3')I in A. baumanii. The most frequent phenotype was resistance to six antibiotics (G, Nt, T, A, K, N) Resistance rates were high for gentamicin (>70 %) in both groups and amikacin (88,89 %) in non-fermentatives.     

Microbiome dynamics of human epidermis following skin barrier disruption

Background

Recent advances in sequencing technologies have enabled metagenomic analyses of many human body sites. Several studies have catalogued the composition of bacterial communities of the surface of human skin, mostly under static conditions in healthy volunteers. Skin injury will disturb the cutaneous homeostasis of the host tissue and its commensal microbiota, but the dynamics of this process have not been studied before. Here we analyzed the microbiota of the surface layer and the deeper layers of the stratum corneum of normal skin, and we investigated the dynamics of recolonization of skin microbiota following skin barrier disruption by tape stripping as a model of superficial injury.

Results

We observed gender differences in microbiota composition and showed that bacteria are not uniformly distributed in the stratum corneum. Phylogenetic distance analysis was employed to follow microbiota development during recolonization of injured skin. Surprisingly, the developing neo-microbiome at day 14 was more similar to that of the deeper stratum corneum layers than to the initial surface microbiome. In addition, we also observed variation in the host response towards superficial injury as assessed by the induction of antimicrobial protein expression in epidermal keratinocytes.

Conclusions

We suggest that the microbiome of the deeper layers, rather than that of the superficial skin layer, may be regarded as the host indigenous microbiome. Characterization of the skin microbiome under dynamic conditions, and the ensuing response of the microbial community and host tissue, will shed further light on the complex interaction between resident bacteria and epidermis.     

Production of dissociated sensory neuron cultures and considerations for their use in studying neuronal function and plasticity

Dissociated primary sensory neurons are commonly used to study growth factor-dependent cell survival, axon outgrowth, differentiation and basic mechanisms of sensory physiology and pain. Spinal or trigeminal sensory neurons can be collected from embryos, neonates or adults, treated with enzymes that degrade the extracellular matrix, triturated and grown in defined media with or without growth factors and additional animal sera. Production of cultures can take as little as 2.5 h. Cells can be used almost immediately or maintained for as long as 1 month. Ease of production and the ability to control growth conditions make sensory neuron culture a powerful model system for studying basic neurobiology of central and peripheral nervous systems.     

Split T cell tolerance against a self/tumor antigen: spontaneous CD4+ but not CD8+ T cell responses against p53 in cancer patients and healthy donors

Analyses of NY-ESO-1-specific spontaneous immune responses in cancer patients revealed that antibody and both CD4(+) and CD8(+) T cell responses were induced together in cancer patients. To explore whether such integrated immune responses are also spontaneously induced for other tumor antigens, we have evaluated antibody and T cell responses against self/tumor antigen p53 in ovarian cancer patients and healthy individuals. We found that 21% (64/298) of ovarian cancer patients but no healthy donors showed specific IgG responses against wild-type p53 protein. While none of 12 patients with high titer p53 antibody showed spontaneous p53-specific CD8(+) T cell responses following a single in vitro sensitization, significant p53-specific IFN-γ producing CD4(+) T cells were detected in 6 patients. Surprisingly, similar levels of p53-specific CD4(+) T cells but not CD8(+) T cells were also detected in 5/10 seronegative cancer patients and 9/12 healthy donors. Importantly, p53-specific CD4(+) T cells in healthy donors originated from a CD45RA(-) antigen-experienced T cell population and recognized naturally processed wild-type p53 protein. These results raise the possibility that p53-specific CD4(+) T cells reflect abnormalities in p53 occurring in normal individuals and that they may play a role in processes of immunosurveillance or immunoregulation of p53-related neoplastic events.     

Effect of chronic viral infection on epitope selection, cytokine production, and surface phenotype of CD8 T cells and the role of IFN-gamma receptor in immune regulation

Regulation of CD8 T cell responses in chronic viral infections is not well understood. In this study, we have compared the CD8 T cell responses to immunodominant and subdominant epitopes during an acute and a chronic lymphocytic choriomeningitis virus (LCMV) infection in mice. The epitope hierarchy of the primary CD8 T cell response was similar in acute and chronic LCMV infections. However, strikingly, the epitope hierarchy of the primary CD8 T cell response was conserved in the T cell memory only in an acute but not in a chronic LCMV infection. Interestingly, in an acute infection, increasing the viral dose caused significant changes in the epitope hierarchy of the LCMV-specific memory CD8 T cell pool, with no effect on the primary CD8 T cell response. Functional and phenotypic analyses revealed that exposure of CD8 T cells to extended periods of antigenic stimulation could lead to long-term defects in cytokine production and alteration in expression of cell surface L-selectin (CD62L). Whereas expression of CD44 was minimally altered, a greater proportion of LCMV-specific memory CD8 T cells were CD62L(low) in mice that have recovered from a chronic LCMV infection, compared with acutely infected mice. Mechanistic studies showed that IFN-gammaR deficiency altered the epitope hierarchy of the pool of LCMV-specific memory CD8 T cells without significantly affecting the immunodominance of the primary CD8 T cell response in an acute infection. Taken together, these findings should further our understanding about the regulation of T cell responses in human chronic viral infections.