Concurrent Generation of Effector and Central Memory CD8 T Cells during Vaccinia Virus Infection

It is generally thought that during the contraction phase of an acute anti-viral T cell reponse, the effector T cells that escape activation-induced cell death eventually differentiate into central memory T cells over the next several weeks. Here we report that antigen-specific CD8T cells with the phenotype and function of central memory cells develop concomitantly with effector T cells during vaccinia virus (vv) infection. As soon as 5 days after an intraperitoneal infection with vv, we could identify a subset of CD44^hi and CD62L⁺ vv-specific CD8 T cells in the peritoneal exudate lymphocytes. This population constituted approximately 10% of all antigen-specific T cells and like central memory T cells, they also expressed high levels of CCR7 and IL-7R but expressed little granzyme B. Importantly, upon adoptive transfer into naïve congenic hosts, CD62L⁺, but not CD62L⁻ CD8 T cells were able to expand and mediate a rapid recall response to a new vv challenge initiated 6 weeks after transfer, confirming that the CD62L⁺ vv-specific CD8 T cells are bonafide memory cells. Our results are thus consistent with the branched differentiation model, where effector and memory cells develop simultaneously. These results are likely to have implications in the context of vaccine design, particularly those based on vaccinia virus recombinants.     

Experimental protein malnutrition in squirrel monkeys: cytochemical interaction of nucleolus and cytoplasm in the anterior horn cells of the spinal cord of Saimiri sciureus.

Nuecleolo-cytoplasmic relationships have been studied using histochemical techniques in the spinal cord of healthy neonates compared with those born to mothers malnourished through most of the gestation period, and healthy and severely protein-malnourished young adult squirrel monkeys. Formaldehyde-fixed as well as fresh frozen tissues were used for histological study and for histochemical techniques to demonstrate lipids, carbohydrates, nucleic acids and enzymes of various metabolic cycles. Changes in the neuronal cytoplasm of the low protein animals appear to be related to impaired protein metabolism and energy transport. The nucleolus reacts to cytoplasmic changes by enlarging its size and by active synthesis of secretion of nucleolar material, which is then passed into the cytoplasm through an evagination of the nuclear envelope. The greater the degree of chromatolysis in the cytoplasm, the more active the nucleolus appears to be in terms of its enlarged size and transfer of secretion products into the cytoplasm. It is believed that the perinuclear accumulation of secretion products in the neuronal cytoplasm of the protein-deficient animals has its origin in the nucleolus. Such an accumulation in the severely malnourished animals appears to be a compensatory mechanism for the increased cytoplasmic catabolism and loss of ribonucleoprotein material in order to facilitate additional protein synthesis for cell survival.     

Cytochemical response of kidney, liver and nervous system of fluoride ions in drinking water.

Morphological and cytochemical studies on the squirrel monkey have been made after maintaining the sujects on pure distilled water and fluoridated distilled water for 18 months with the objective of determining the effect of fluoride on the activity of some hydrolytic and oxidative enzymes in the kidney, liver and nervous system. Daily water intake by individual animals was measured over the final 10 months of the animal's exposure to 0,1 and 5 ppm fluoride. Water consumption was considerably higher in the animals on higher fluoride intake. Whereas the nervous system remained totally unaffected by this experimental procedure, the liver showed a slightly enhanced acivity of Krebs citric acid cycle enzymes. The kidneys, however, showed significant cytochemical changes, especially in the animals on 5 ppm fluoride intake in their drinking water. In these animals, the glomeruli showed an increase in the activity of acid phosphatase and the enzymes belonging to the citric acid cycle and the pentose shunt, whereas lactate dehydrogenase, a resentative of the anaerobic glyoclytic pathway, remained unchanged or only slightly changed. These observations suggest that fluoride in concentrations as low as 5 ppm interferes to some extent with the intracellular metabolism of the excretory system.     

Effect of glutaraldehyde fixation on the localization of various oxidative and hydrolytic enzymes in the brain of rhesus monkey, Macaca mulatta

Synopsis Histochemical investigations have been made on the localization of certain oxidative and hydrolytic enzymes in the different areas of rhesus monkey brain using unfixed, freshfrozen tissue and 3% glutaraldehyde-fixed material. After glutaraldehyde fixation, the oxidative enzymes lose most of their activity normally demonstrable in the fresh-frozen section. The hydrolytic enzymes are somewhat resistant to fixation but also lose about half of the enzyme activity observed after no fixing procedure. The glycogen is better preserved in the glutaraldehyde-fixed material compared to fresh-frozen or even formaldehyde-fixed tissue. The significance of these observations is discussed in relation to glutaraldehyde as a fixative of choice in electron histochemistry.List of abbreviations used in the Figures ALH area lateralis hypothalami - APH area posterior hypothalami - AS aquaeductus Sylvii - ATN anterior thalamic nuclei - BC brachium conjunctivum - CC corpus callosum - CD nucleus caudatus - CI capsula interna - CIS cortex insularis - CM centrum medianum thalami - COR corona radiata - CP commissura posterior - CSR colliculus superior - EM eminentia medialis - F fornix - GC substantia grisea centralis - GLM corpus geniculatum laterale, magnocellular part - GLP corpus geniculatum laterale, parvocellular part - GP globus pallidus - LD nucleus lateralis dorsalis thalami - LME lamina medullaris externa thalami - LMI lamina medullaris interna thalami - LP nucleus lateralis posterior thalami - MD nucleus medialis dorsalis thalami - ML nucleus lateralis corpus mammillaris - MM nucleus medialis corpus mammillaris - NC nucleus centralis thalami - NCI nucleus colliculi inferioris - NLL nucleus lemnisci lateralis - NR nucleus ruber - NSTH nucleus subthalamicus - N III nervus oculomotorius - PC nucleus paracentralis thalami - PCR pedunculus cerebri - PUT Putamen - PV nucleus paraventricularis hypothalami - R nucleus reticularis thalami - RU nucleus reuniens thalami - SM stria medullaris thalami - SMH nucleus supramammillaris hypothalami - SMT nucleus submedius thalami - SN substantia nigra - TO tractus opticus - VL nucleus ventralis lateralis thalami - VP nucleus ventralis posterior thalami - ZI zona incerta - II ventriculus lateralis - III ventriculus tertius     

HISTOCHEMICAL MAPPING OF LACTATE DEHYDROGENASE AND MONOAMINE OXIDASE IN THEMEDULLA OBLONGATA AND CEREBELLUM OF SQUIRREL MONKEY (SAIMIRI SCIUREUS)

Abstract— —The gross distribution of LDH and MAO was studied in a caudo-cranial series of 50 μ thick sections through the medulla oblongata and cerebellum. In general, LDH exhibited a stronger reaction in the neuropil and in the perikarya, whereas MAO showed moderate activity in the neurons and mild to moderate activity in the neuropil. The axonal processes and nerve fibres showed comparatively stronger MAO activity. The nuclei gracilis, cuneatus medialis and lateralis, cranial nerve nuclei, olivaris inferior, vestibularis and cochlearis nuclei showed particularly strong LDH and equally weak MAO activities. The lateral part of the formato reticularis myelencephali showed much more MAO than did the medial part, whereas the LDH reaction was uniformly strong. The reticularis lateralis showed uniformly strong LDH and very mild MAO activities.
In the cerebellar cortex, the MAO activity was concentrated in the molecular layer and nerve fibre layer, whereas LDH activity was particularly strong in the Purkinje cells and their processes in the molecular layer. The cerebellar nuclei showed strong LDH and weak MAO in the neutrons and stronger MAO and moderate LDH in the neuropil.     

Enzyme histochemistry of the mesenteric and dorsal root ganglion cells of cat and squirrel monkey

Summary A detailed histochemical study has been made on the mesenteric ganglia of the cat, and dorsal root ganglia of the squirrel monkey by the use of appropriate histochemical techniques accompanied by appropriate controls for phosphatases, esterases, and oxidative enzymes. The different neurons of a particular ganglion show varied amounts of enzyme activity at a particular time depending upon the functional state of the neurons. SDH, CYO and LDH reaction is prominent in the cytoplasm of the neurons, gliocytes and satellite cells, whereas the MAO preparations generally show a weak reaction. The AK is prominent in the neuropil, cell membranes and peripheral part of cytoplasm, whereas ATPase activity has been observed in blood vessels as well. In AC preparations the area of lipofuscin concentration shows more intense reaction than the rest of the cytoplasm. The activity of AChE and BChE varies from mild, to moderate to strong. The TPPase preparations show morphologically different types and amounts of TPPase positive Golgi material even in the adjoining cells. The relationship between the TPPase Golgi material and various oxidative and dephosphorylating enzymes has been briefly discussed.Abbreviations used AC Acid phosphatase - AChE Acetyl-cholinesterase (specific) - AK Alkaline phosphatase - AMPase Adenosine monophosphatase (5-nucleotidase) - ATPase Adenosine triphosphatase - BChE Butyryl-cholinesterase (nonspecific) - CYO Cytochrome oxidase - DPN-D DPN-diaphorase - G6P Glucose-6-phosphatase - LDH Lactic dehydrogenase - MAO Monoamine oxidase - MDH Malic dehydrogenase - NAD-D NAD-diaphorase - SDH Succinic dehydrogenase - SE Simple esterase - TPPase thiamine pyrophosphatase T. R. Shanthaveerappa in previous publications.     

Coronary heart disease alters intercellular communication by modifying microparticle-mediated microRNA transport

Coronary heart disease (CHD) is characterized by abnormal intercellular communication and circulating microRNAs (miRNAs) are likely involved in this process. Here, we show that CHD was associated with changes in the transport of circulating miRNA, particularly decreased miRNA enrichment in microparticles (MPs). Additionally, MPs from CHD patients were less efficient at transferring miRNA to cultured HUVECs, which correlated with their diminished capacity to bind developmental endothelial locus-1 (Del-1). In summary, CHD was associated with distinct changes in circulating miRNA transport and these changes may contribute to the abnormal intercellular communication that underlies CHD initiation and progression.     

Cytochemistry of experimental protein malnutrition in primates: effect on the spinal cord of the squirrel monkey, Saimiri sciureus

Synopsis The localization of certain phosphatases, esterases and dehydrogenases in the spinal cord of healthy and severely protein malnourished squirrel monkeys were investigated histochemically. The latter were given drastically reduced levels of proteins in their diets for 15 weeks, and for the purpose of comparison several animals were sacrificed after 9, 11, 13 and 15 weeks on the feeding schedule. Cytochemical investigations were carried out on sections prepared from fresh-frozen spinal cord removed from the animal in the shortest possible time after an appropriate dose of nembutal anaesthesia. The distribution of thiamine pyrophosphatase, inosine diphosphatase, acid phosphatase and ATPase was found to be significantly altered under the impact of dietary abuse. The changes appear to be related to altered protein metabolism, energy transport and general slowing down of the metabolic reactions. The results obtained on phosphatases are reinforced by the distribution of enzymes of the Krebs cycle, pentose shunt and anaerobic metabolic pathways. Whereas the activity of the Krebs cycle enzymes is greatly reduced, the pentose shunt reacts to protein deprivation by increasing the level of activity of its enzymes. Similarly the activities of enzymes of the anaerobic pathway are also enhanced. The significance of these observations and the role of glial cells along with the neuron as a functional unit are discussed.