Homeostatic Control of Memory Cell Progenitors in the Natural Killer Cell Lineage

SummaryRecent studies have demonstrated that natural killer (NK) cells are able to undergo clonal expansion and contraction and to generate self-renewing memory cells after infection with mouse cytomegalovirus (MCMV). It is unclear whether all or only certain subsets preferentially contribute to the generation of memory NK cells. Here, we show that memory NK cells predominantly arise from killer cell lectin-like receptor G1 (KLRG1)-negative NK cell progenitors, whereas KLRG1-positive NK cells have limited capacity for expansion during infection with MCMV. Unexpectedly, the frequency of KLRG1-positive NK cells is significantly affected by the presence of T cells in the host and potentially by the host microbiota. Our findings demonstrate that excessive availability of interleukin (IL)-15 may erode the pool of memory progenitors, resulting in the decreased efficiency of memory generation in the NK cell lineage

Structural variation in the glycogen synthase kinase 3β and brain‐derived neurotrophic factor genes in Japanese patients with bipolar disorders

Background: Lithium is the first‐line drug for the treatment of bipolar disorders (BDs); however, not all patients responded. Glycogen synthase kinase (GSK) 3β and brain‐derived neurotrophic factor (BDNF) play a role in the therapeutic action of lithium. Since structural variations were reported in these genes, it is possible that these genomic variations may be involved in the therapeutic responses to lithium. Method: Fifty patients with BDs and 50 healthy subjects (mean age 55.0 ± 15.0 years; M/F 19/31) participated. We examined structural variation of the GSK3β and BDNF genes by real‐time PCR. We examined the influence of structural variation of these genes on the therapeutic responses to lithium and the occurrence of antidepressant‐emergent affective switch (AEAS). The efficacy of lithium was assessed using the Alda scale, and AEAS was evaluated using Young Mania Rating Scale. Results: Although we examined structural variations within intron II and VII of the GSK3® gene and from the end of exon IV to intron IV and within exon IX of the BDNF gene, no structural variation was found in BDs. Whereas 5 of 50 patients exhibited three copies of the genomic region within exon IV of the BDNF gene, all healthy subjects had two copies. No difference in the therapeutic efficacy of lithium was found between patients with three and two copies. No difference in the occurrence of AEAS was found between the two groups. Conclusion: The amplification of the BDNF gene influenced neither the therapeutic responses to lithium nor the occurrence of AEAS

Investigation of inter-annual variation in the feeding habits of Japanese sardine (Sardinops melanostictus) and mackerels (Scomber spp.) in the Western North Pacific based on bulk and amino acid stable isotopes

Inter-annual variation in the feeding habits and food sources of Japanese sardine and mackerel at age-0 and age-1+ caught in the Kuroshio-Oyashio transition zone of the Western North Pacific were investigated based on analyses of bulk stable isotopes (δ13C, δ15N) and amino acid nitrogen isotopes (δ15NAA). Differences in δ13C and δ15N between Japanese sardine and mackerel were small for age-0, and inter-annual variation trends were similar, suggesting they depend on similar food sources in the same food web at this age. In contrast, inter-annual variation in δ13C and δ15N were significantly different between both species at age-1+, and both δ15N of phenylalanine (δ15NPhe: an indicator of nitrogen source) and trophic position estimated from δ15NAA (TPAA) were higher in mackerel, suggesting that the two species depend on distinct food webs as they age. Inter-annual variations in δ15NPhe were considered to have different causes for the two species; differences in food web structure due to the degree of southward intrusion of the Oyashio Current for Japanese sardine, compared to a shift in migration area and depth for mackerel. Furthermore, competition for food due to the recent increases in the population densities of both fishes appeared to be reflected in increased TPAA of mackerel. Although they are caught in the same region, the mechanism of variation in food sources differs because of differences in migration area, depth, and feeding habits. Differences in the feeding habits of Japanese sardine and mackerel may affect trophic status and spawning characteristics, potentially leading to different shifts in stock abundances

Natural killer cells: walking three paths down memory lane

Immunological memory has traditionally been regarded as a unique feature of the adaptive immune response, mediated in an antigen-specific manner by T and B lymphocytes. All other hematopoietic cells, including natural killer (NK) cells, are classified as innate immune cells, which have been considered short-lived but can respond rapidly against pathogens in a manner not thought to be driven by antigen. Interestingly, NK cells have recently been shown to survive long term after antigen exposure and subsequently mediate antigen-specific recall responses. In this review, we address the similarities between, and the controversies surrounding, three major viewpoints of NK memory that have arisen from these recent studies: (i) mouse cytomegalovirus (MCMV)-induced memory; (ii) cytokine-induced memory; and (iii) liver-restricted memory cells

Rapid and sequential quantitation of salivary gland-associated mouse cytomegalovirus in oral lavage.

Cytomegalovirus (CMV) establishes a persistent infection in the salivary glands and transmits to other hosts. Mouse cytomegalovirus (MCMV) is a well-characterized model for studying the mechanisms of host responses against CMV. The viral load in salivary glands has been measured traditionally because it has been considered to reflect the consequence of anti-virus responses by T cells and natural killer (NK) cells. However, the standard plaque assay is cumbersome and it is impossible to monitor sequentially the viral load in same host. Hence, the goal of this study was to develop a real-time quantitative PCR (qPCR)-based procedure to measure the viral load in oral lavage. This report demonstrates that the viral load in oral lavage correlates well with viral titers in the salivary glands. This method allows sequential quantitation of viral loads without sacrificing mice and provides a technique that will facilitate kinetic studies of anti-viral immunity mediated by the innate and adaptive immune systems

Rapid and sequential quantitation of salivary gland-associated mouse cytomegalovirus in oral lavage.

Cytomegalovirus (CMV) establishes a persistent infection in the salivary glands and transmits to other hosts. Mouse cytomegalovirus (MCMV) is a well-characterized model for studying the mechanisms of host responses against CMV. The viral load in salivary glands has been measured traditionally because it has been considered to reflect the consequence of anti-virus responses by T cells and natural killer (NK) cells. However, the standard plaque assay is cumbersome and it is impossible to monitor sequentially the viral load in same host. Hence, the goal of this study was to develop a real-time quantitative PCR (qPCR)-based procedure to measure the viral load in oral lavage. This report demonstrates that the viral load in oral lavage correlates well with viral titers in the salivary glands. This method allows sequential quantitation of viral loads without sacrificing mice and provides a technique that will facilitate kinetic studies of anti-viral immunity mediated by the innate and adaptive immune systems

Beam-divergence deconvolution for diffractive imaging

This Rapid Communication presents a method of beam-divergence deconvolution for diffractive imaging. First, the detected diffraction intensity is formulated as a convolution between the diffraction intensity of parallel incident beams and the divergence of an incident beam. It is shown numerically that the convolution causes the reconstructed image to shrink and become blurred. Next, the algorithm of deconvolution used in the iterative Fourier phase retrieval method is applied to the convoluted diffraction intensity deteriorated by quantum noise. Numerical simulations show that the proposed algorithm recovers the deconvoluted diffraction intensity and improves the reconstructed image. Finally, the algorithm is applied to an electron-beam experiment to reconstruct a multiwall carbon nanotube. The results verified that the algorithm reduces the influence of beam divergence

An Iterative Inverse Filter Design For The Multi-Channel Sound Field Reproduction System

WESTPRAC VII 2000: the 7th West Pacific Regional Acoustics Conference, October 3-5, 2000, Kumamoto, Japan.In order to realize the multi-channel sound field reproduction system, it is indispensable to design inverse filters that remove the effect of room transfer functions. The design method in the frequency domain based on the least-norm-solution (LNS) is less memory and less calculation than the design method in the time domain. However, the LNS method cannot guarantee the causality and stability of the filters. In this paper, a design method of a time domain inverse filter using iterative processing in the frequency domain for multi-channel sound field reproduction is proposed, and the numerical analysis result is described. The proposed method can decrease the squared error for every sensor by 3-12 dB. Furthermore, the reproduced sound by this method attains over 13 dB improvement in the segmental SNR compared with one designed by the LNS method for real environment impulse responses