Cross-tissue immune cell analysis reveals tissue-specific features in humans.

Despite their crucial role in health and disease, our knowledge of immune cells within human tissues remains limited. We surveyed the immune compartment of 16 tissues from 12 adult donors by single-cell RNA sequencing and VDJ sequencing generating a dataset of ~360,000 cells. To systematically resolve immune cell heterogeneity across tissues, we developed CellTypist, a machine learning tool for rapid and precise cell type annotation. Using this approach, combined with detailed curation, we determined the tissue distribution of finely phenotyped immune cell types, revealing hitherto unappreciated tissue-specific features and clonal architecture of T and B cells. Our multitissue approach lays the foundation for identifying highly resolved immune cell types by leveraging a common reference dataset, tissue-integrated expression analysis, and antigen receptor sequencing.

Human immunology studies using organ donors: Impact of clinical variations on immune parameters in tissues and circulation.

Organ donors are sources of physiologically healthy organs and tissues for life-saving transplantation, and have been recently used for human immunology studies which are typically confined to the sampling of peripheral blood. Donors comprise a diverse population with different causes of death and clinical outcomes during hospitalization, and the effects of such variations on immune parameters in blood and tissues are not known. We present here a coordinate analysis of innate and adaptive immune components in blood, lymphoid (bone marrow, spleen, lymph nodes), and mucosal (lungs, intestines) sites from a population of brain-dead organ donors (2 months-93 years; n = 291) across eight clinical parameters. Overall, the blood of donors exhibited similar monocyte and lymphocyte content and low serum levels of pro-inflammatory cytokines as healthy controls; however, donor blood had increased neutrophils and serum levels of IL-8, IL-6, and MCP-1 which varied with cause of death. In tissues, the frequency and composition of monocytes, neutrophils, B lymphocytes and T cell subsets in lymphoid or mucosal sites did not vary with clinical state, and was similar in donors independent of the extent of clinical complications. Our results reveal that organ donors maintain tissue homeostasis, and are a valuable resource for fundamental studies in human immunology.

Local dispersal of Puccinia striiformis f. sp. tritici from isolated source lesions.

Understanding how disease foci arise from single source lesions has not been well studied. Here, single wheat leaves were inoculated with Puccinia striiformis f. sp. tritici urediniospores, and all wheat leaves within two intersecting 0.3 × 3.0 m transects were sampled in eight replicates over three years. The lesions observed on each of the top three leaves on plants within 1.5 m from the source lesion were three-dimensionally mapped. The total number of lesions within a 1.5 m radius was estimated by dividing the number of lesions observed within each 0.025 m-wide annulus by the fraction of the annulus sampled. The estimated total number of lesions produced within 1.5 m of a single source lesion ranged from 27 to 776, with a mean of 288 lesions. Eighty percent of the lesions were recorded within 0.69 m of the source infection. The proportion of total lesions observed at a given distance from the source was fitted well by the Lomax and Weibull distributions, reflecting the large proportion of lesions arising close to the source, and when fitted to an inverse-power distribution had a slope (b) of 2.5. There were more lesions produced on leaves higher in the canopy than on lower leaves, with more lesions being detected above than below the point of inoculation. Simultaneous measurement of lesion gradients and spore dispersal in the final year of the study suggests that this pattern is due to greater susceptibility of upper leaves, rather than increased dispersal to upper leaves.

Effect of Plant Age and Leaf Position on Susceptibility to Wheat Stripe Rust.

In addition to pathogen propagule dispersal, disease spread requires successful infection of host tissue. In plant disease epidemiology, susceptibility of host tissue is often assumed to be constant. This assumption ignores changes in host phenology due to developmental stage. To examine this assumption, 3-, 4-, and 5-week-old wheat plants were inoculated with equal quantities of urediniospores of Puccinia striiformis f. sp. tritici, the causal agent of wheat stripe rust (WSR). Disease severity on each leaf was assessed and fit by mixed-effect linear model as a function of leaf position and plant age. Younger plants had significantly greater disease severity than older plants, with mean severities of 50.4, 30.1, and 12.9% on plants that were 3, 4, and 5 weeks old, respectively, at time of inoculation. This effect was greater on leaves higher on the plant. Within same-aged plants, younger leaves had significantly greater disease severity than older leaves, with mean severities of 40.2, 34.8, and 17.7% on the uppermost, second, and third leaf, respectively. These results suggest that the vertical distribution of WSR lesions in agricultural fields could be driven by differences in host susceptibility more so than propagule dispersal.

[Multidrug-Resistant Organisms (MDRO) in Rehabilitation Clinics in the Rhine-Main District, Germany, 2014: Risk Analysis and Hygiene Procedures]. / Multiresistente Erreger in Rehabilitationseinrichtungen im Rhein-Main-Gebiet, Deutschland, 2014: II. Ärztliche Risikoanalyse und Hygienemaßnahmen.

BACKGROUND: Many regional German MDRO-networks aim to improve the medical rehabilitation of patients with methicillin-resistant Staphylococcus aureus (MRSA) and other multidrug-resistant pathogens. In 2014, the German Commission for Hospital Hygiene and Infection Control (KRINKO) released revised recommendations for the care of patients with MRSA. In particular, for rehabilitation facilities, these recommendations stipulated a medical risk analysis to establish necessary hygiene measures, and provide specific recommendations. MATERIAL AND METHODS: Based on a large investigation carried out in 21 rehabilitation facilities covering different medical specialties, medical risk analyses according to KRINKO were performed, and the findings evaluated separately for orthopedic, cardiologic, oncologic, neurologic, or geriatric facilities, as well as for all institutions taken together. RESULTS: The overall colonization pressure, i. e. the point prevalence of MRSA and extended spectrum beta-lactamase-producing gram-negative pathogens (ESBL) among hospitalized rehabilitation patients was found to be 0.7% and 7.7%, respectively. Impairment of the intact skin (an established risk factor for persisting MRSA colonization and MRSA infection) was found in 7% of the patients, impaired mobility requiring enhanced level of care in 4.1%, and mental confusion and/or incontinence (potentially impairing the application of hygiene measures) in 11% of patients. Compared to the total study population, there was an increase in all risk factors in geriatric and neurologic rehabilitation patients: skin barrier breaches (in neurologic and in geriatric patients: 18.3 and 19.2%, respectively), impaired mobility (32.7 and 37.0%, respectively), and mental confusion/incontinence (24.5 and 28.0%, respectively). In addition, geriatric patients demonstrated an increased overall prevalence of multidrug-resistant organisms (MRSA: 9.4%; ESBL: 22.7%). DISCUSSION: Risk analysis according to KRINKO showed that in rehabilitation facilities with internal medicine or orthopedics specialties, there was a comparably lower risk for transmission, colonization, and/or infection with multidrug-resistant pathogens, as against institutions with neurologic or geriatric specialty. It appears that in the first type of rehabilitation facilities, consistently carried out basic hygiene measures are sufficient while in neurologic or geriatric rehabilitation hospitals, these measures should be supplemented with additional hygiene measures based on medical risk analysis. Furthermore, for infection control purposes in rehabilitation facilities, patient isolation will be rarely necessary or appropriate. These analyses suggest that in the future, rehabilitation programs for MRSA/ESBL-colonized patients will be more successful.

[Brain Organization of the Preparation for Visual Recognition in Preadolescent Children].

The brain organization of the process of preparation for the perception of incomplete images fragmented to different extents. The functional connections of ventrolateral and dorsoventral cortical zones with other zones in 10-11-year-old and 11-12-year-old children were studied at three successive stages of the preparation for the perception of incomplete images. These data were compared with those obtained for adults. In order to reveal the effect of preparatory processes on the image recognition, we also analyzed the regional event-related potentials. In adults, the functional interaction between dorsolateral and ventrolateral prefrontal cortex and other cortical zones of the right hemisphere was found to be enhanced at the stage of waiting for not-yet-recognizable image, while in the left hemisphere the links became stronger shortly before the successful recognition of a stimulus. In children the stage-related changes in functional interactions are similar in both hemispheres, with peak of interaction activity.at the stage preceding the successful recognition. It was found that in 11-12-year-old children the ventrolateral cortex is involved in both preparatory stage and recognition processes to a smaller extent as compared with adults and 10-11-year-old children. At the same time, the group of 11-12-year-old children had more mature pattern of the dorsolateral cortex involvement, which provided more effective recognition of incomplete images in this group as compared with 10-11-year-old children. It is suggested that the features of the brain organization of visual recognition and preceding preparatory processes in 11-12-year-old children are caused by multidirectional effects of sex hormones on the functioning of different zones of the prefrontal cortex at early stages of sexual maturation.

[Multidrug-Resistant Organisms (MDRO) in Rehabilitation Clinics in the Rhine-Main-District, Germany, 2014: Prevalence and Risk Factors]. / Multiresistente Erreger in Rehabilitationseinrichtungen im Rhein-Main-Gebiet, Deutschland, 2014: I. Prävalenz und Risikofaktoren.

BACKGROUND: While a limited number of studies have investigated the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in medical rehabilitation institutions, almost no data on the colonization of rehabilitation patients with multiresistant gram-negative rods is available. Here we report on a large multicenter study on the prevalence of MRSA and multiresistant pathogens in rehabilitation institutions in the Rhine-Main area in 2014. MATERIALS AND METHODS: Altogether, 21 rehabilitation hospitals participated. For all patients, age, gender, previous history of hospitalizations, surgery, previous colonization with multidrug-resistant organisms, use of a medical device, current antimicrobial therapy, and the current infection status were ascertained. On voluntary basis, nare and throat swabs were taken for analysis of MRSA and rectal swabs were tested for extended spectrum betalactamase-producing gram-negative bacteria (ESBL). RESULTS: 50% of 2 440 patients had a history of hospitalization within the previous 6 months while 39% had undergone surgery during the past 30 days. Approximately a quarter of the patients had been transferred to a rehabilitation hospital directly from an acute care hospital, had been under antimicrobial therapy with the past three months, or had travelled to a foreign country within the previous year. Risk factors such as lesions of the intact skin or presence of medical devices were rarely reported (< 5%) within the exception of patients undergoing geriatric or neurologic acute care rehabilitation. 0.7% (15/2155) of the patients were colonized with MRSA, while 7.7% (110/1434) showed a positive result for ESBL. The highest prevalence rates for multiresistant organisms were encountered among patients with neurologic rehabilitation (MRSA, 1.3%, and ESBL, 10.2%) or with geriatric rehabilitation (MRSA, 9.4%, and ESBL, 22.7%). CONCLUSION: In the rehabilitation patient population, the prevalence rates of MRSA and ESBL were found to be in the range of rates encountered in the general population (reported rates for MRSA, 0.5%, and ESBL, 6.3%). The known risk factors for MRSA such as skin lesions, medical devices and previous history for MRSA were also confirmed among this patient population. Direct transfer from an acute care hospital, antimicrobial treatment during the past 3 months, and wounds proved significant risk factors for ESBL colonization. Patients of neurologic rehabilitation and geriatric patients showed the highest rates of risk factors and the highest prevalence rates of multidrug-resistant organisms. It appears to be of importance for rehabilitation hospitals to be geared to the needs of patients with multidrug-resistant organisms, and prevent the transmission of these pathogens by appropriate hygiene measures.

Macrochimerism in Intestinal Transplantation: Association With Lower Rejection Rates and Multivisceral Transplants, Without GVHD.

Blood chimerism has been reported sporadically among visceral transplant recipients, mostly in association with graft-vs-host disease (GVHD). We hypothesized that a higher degree of mixed chimerism would be observed in multivisceral (MVTx) than in isolated intestinal (iITx) and isolated liver transplant (iLTx) recipients, regardless of GVHD. We performed a longitudinal prospective study investigating multilineage blood chimerism with flow cytometry in 5 iITx and 4 MVTx recipients up to one year posttransplant. Although only one iITx patient experienced GVHD, T cell mixed chimerism was detected in 8 out of 9 iITx/MVTx recipients. Chimerism was significantly lower in the four subjects who displayed early moderate to severe rejection. Pre-formed high-titer donor-specific antibodies, bound in vivo to the circulating donor cells, were associated with an accelerated decline in chimerism. Blood chimerism was also studied in 10 iLTx controls. Among nonsensitized patients, MVTx recipients exhibited greater T and B cell chimerism than either iITx or iLTx recipients. Myeloid lineage chimerism was present exclusively among iLTx and MVTx (6/13) recipients, suggesting that its presence required the hepatic allograft. Our study demonstrates, for the first time, frequent T cell chimerism without GVHD following visceral transplantation and a possible relationship with reduced rejection rate in MVTx recipients.

The prostaglandin D2 receptor CRTH2 regulates accumulation of group 2 innate lymphoid cells in the inflamed lung.

Group 2 innate lymphoid cells (ILC2s) promote type 2 cytokine-dependent immunity, inflammation, and tissue repair. Although epithelial cell-derived cytokines regulate ILC2 effector functions, the pathways that control the in vivo migration of ILC2s into inflamed tissues remain poorly understood. Here, we provide the first demonstration that expression of the prostaglandin D2 (PGD2) receptor CRTH2 (chemoattractant receptor-homologous molecule expressed on Th2 cells) regulates the in vivo accumulation of ILC2s in the lung. Although a significant proportion of ILC2s isolated from healthy human peripheral blood expressed CRTH2, a smaller proportion of ILC2s isolated from nondiseased human lung expressed CRTH2, suggesting that dynamic regulation of CRTH2 expression might be associated with the migration of ILC2s into tissues. Consistent with this, murine ILC2s expressed CRTH2, migrated toward PGD2 in vitro, and accumulated in the lung in response to PGD2 in vivo. Furthermore, mice deficient in CRTH2 exhibited reduced ILC2 responses and inflammation in a murine model of helminth-induced pulmonary type 2 inflammation. Critically, adoptive transfer of CRTH2-sufficient ILC2s restored pulmonary inflammation in CRTH2-deficient mice. Together, these data identify a role for the PGD2-CRTH2 pathway in regulating the in vivo accumulation of ILC2s and the development of type 2 inflammation in the lung.

Lung niches for the generation and maintenance of tissue-resident memory T cells.

The extent to which tissue-specific viral infections generate memory T cells specifically adapted to and maintained within the target infection site is unknown. Here, we show that respiratory virus-specific memory T cells in mice and humans are generated and maintained in compartmentalized niches in lungs, distinct from populations in lymphoid tissue or circulation. Using a polyclonal mouse model of influenza infection combined with an in vivo antibody labeling approach and confocal imaging, we identify a spatially distinct niche in the lung where influenza-specific T-cell responses are expanded and maintained long term as tissue-resident memory (T(RM)) CD4 and CD8 T cells. Lung T(RM) are further distinguished from circulating memory subsets in lung and spleen based on CD69 expression and persistence independent of lymphoid stores. In humans, influenza-specific T cells are enriched within the lung T(RM) subset, whereas memory CD8 T cells specific for the systemic virus cytomegalovirus are distributed in both lung and spleen, suggesting that the site of infection affects T(RM) generation. Our findings reveal a precise spatial organization to virus-specific T-cell memory, determined by the site of the initial infection, with important implications for the development of targeted strategies to boost immunity at appropriate tissue sites.

[Functional organization of the cerebral cortex during preparation to recognition of incomplete linedrawings in 7-8 years-old children and adults].

Functional interaction between prefrontal, temporal and tempo-parieto-occipital zones during preparation to recognition of incomplete linedrawings were analyzed in adults (n = 26) and children of 7-8 years old (n = 20). The strength of cortico-cortical interactions was estimated with the imaginary part of the complex-valued coherence at the frequency of alpha-rhythm (Jα). The Jα value was analyzed in the following three experimental conditions which corresponded to different stages of preparation to visual recognition: nonspecific sustained attention in the period preceding the cue (C1); focused attention in the period preceding a not-yet-recognized target stimulus (C2) and focused attention prior the successfully recognized stimulus (C3). When sustained attention changed to focused attention toward a target stimulus Jα increased in adults but decreased in children. Comparing Jα in the subgroups of both adults and children that showed highest recognition scores helped to uncover the age-related pattern of rearrangement of the cortico-cortical functional interactions in alpha-rhythm. That pattern was found to be hemisphere-specific and different at different stages of preparation to recognition of incomplete linedrawings. In adults, the maximal Jα were found in the left hemisphere during the period preceding the recognition of a target stimulus. At this stage of the functional preparatory tuning, in adults, Jα in the left hemisphere was significantly greater than in children. In adults, Jα related to the right hemisphere attained the highest values when attention was directed to not-yet-recognized stimuli. These values were significantly higher than similar values measured in children. In children, Jα reached its highest value during sustained attention. The characteristic pattern of functional interactions among prefrontal, temporal and temporo-parieto-occipital cortices that observed in children of 7-8 years old during preparatory functional tuning for the recognition of incomplete linedrawings is considered to be an indication of relative immaturity of mechanisms of directed voluntary attention and working memory.

[The functional brain organization during preparation for recognizing incomplete images].

The functional interaction between prefrontal cortex and other cortices was analyzed during the pre-stimulus period in the task in which human subjects (n = 36) were asked to recognize a set of incomplete images of different degree of fragmentation. The imaginary part of the complex-valued coherency was used to measure a strength of inter-area coupling at the alpha-rhythm frequency. Based on the analysis of individual responses the two equal sub-groups (n = 13) showing the lowest and highest recognition scores were extracted from the whole group of subjects. It is shown that the pattern of the functional cortico-cortical interactions as well as the direction of its' changes differ in the two sub-groups. In those subjects who successfully solve the cognitive task, the changes in functional connectivity indices in the situation of focused attention are most pronounced in the right hemisphere if stimulus-to-come would not be recognized. Period preceding recognized stimulus is characterized by the increased cortico-cortical coupling in the left hemisphere. In that sub-group, the values of imaginary part of alpha-coherency show the growth in both hemispheres when the period of focused attention is compared against the period of nonspecific attention. On the contrary, the similar comparison for the sub-group of the least successful subjects shows the imaginary coherency decreases in both hemispheres. These results suggest the constructive role of the alpha-rhythm in functional assembling the prefrontal cortex during the period that precedes the recognition of incomplete images.

[Brain organization of recognition of fragmented pictures in subjects who show different levels of the task performance success].

We studied the behavioral and EEG changes in healthy adults during the recognition of fragmented pictures presented in a series beginning with a low fragmentation level up to the complete figure. Our sample was divided into two groups according to the recognition success. The first group had a small amount of mistakes. The other group had a significantly higher amount of mistakes as compared to the first group; this group had a lower reaction time and recognition threshold (i.e. the fragmentation level at which the object became recognizable). The ERP analysis showed the statistical dependence between the recognition success and the involvement of the frontal and caudal cortical areas. As compared to the second group, in the first one we found no significant association between the recognition process and both early and late ERP components in the dorsolateral prefrontal cortex; we found the increase of sensory-specific components P1 and P2 in caudal areas. These results support the hypothesis of the impact of the prefrontal cortex on the successfulness of recognition of fragmented pictures.

[Development of mechanisms of recognition fragmented images at the preschool and early school ages].

Psychophysical and electrophysiological indices of recognition of incomplete objects with progressive increasing of fragments, were studied in children of three age groups: 5-6, 7-8 and 9-10 years old. It is shown that most pronounced change in the effectiveness of recognition takes place between 5-6 and 7-8 years of age. In the group of children of 5-6, neither significant influence of the recognition process on ERP was found in the prefrontal cortex nor any significant growth of the Nd component was observed over extrastriate cortex. However, in the extrastriate cortex, the amplitude N170-200 component that reflects sensory analysis and encoding extracted features did increase. In the majority of children of this age, the immaturity of the prefrontal cortex manifest itself in the deficit of inhibitory control that results in the tendency to give the impulsive responses and make numerous errors. In children of 7-8, successful recognition is accompanied by the growth of the amplitude of N100 and N250 components over the prefrontal cortex and the growth of NcI component over the extrastriate cortex. In these children, when compared to the children of 5-6, a significant reduction, is observed in the error rate and the recognition threshold. By the age of 9-10 years, the growing role of the prefrontal cortex shows in greater gain in the Nd amplitude and the later ERP component that correspond to cognitive operations related to the recognition process. The results of the study point to the qualitative difference in the mechanisms of recognition between pre-school children and the younger school-children. At the age of 5-6, recognition is carried out on the basis of integration of sensory signs of objects. Since the 7-8 age, in recognition of fragmented images major role belongs to the prefrontal cortex, with its participation search of possible analogs of object in memory and the object identification is carried out.

Endogenous expansion of regulatory T cells leads to long-term islet graft survival in diabetic NOD mice.

Donor pancreatic lymph node cells (PLNC) protect islet transplants in Non-obese diabetic (NOD) mice. We hypothesized that induced FoxP3(+) regulatory T cells (Tregs) were required for long-term islet engraftment. NOD or NOD.NON mice were treated with ALS (antilymphocyte serum) and transplanted with NOR islets +/-PLNC (5 × 10(7) ). In vivo proliferation and expansion of FoxP3(+) Tregs was monitored in spleen and PLN from ALS- and ALS/PLNC-treated recipient mice. Anti-CD25 depletion was used to determine the necessity of Tregs for tolerance. FoxP3(+) numbers significantly increased in ALS/PLNC-treated recipients compared to ALS-treated mice. In ALS/PLNC-treated mice, recipient-derived Tregs localized to the transplanted islets, and this was associated with intact, insulin-producing ß cells. Proliferation and expansion of FoxP3(+) Tregs was markedly increased in PLNC-treated mice with accepted islet grafts, but not in diabetic mice not receiving PLNC. Deletion of Tregs with anti-CD25 antibodies prevented islet graft tolerance and resulted in rejection. Adoptive transfer of Tregs to secondary NOD.scid recipients inhibited autoimmunity by cotransferred NOD effector T cells. Treg expansion induced by ALS/PLNC-treatment promoted long term islet graft survival. Strategies leading to Treg proliferation and localization to the transplant site represent a therapeutic approach to controlling recurrent autoimmunity.

[Development of function of the recognition of angry face expression in children of 5-11 years old].

At children 5-6, 7-8 and 10-11 years on model of cognitive set are revealed age features of influence of last experience on perception of a face expression. At children of 5-6 years rigid set on an angry face was experimentally formed: at a testing stage show set-shifting caused large number of erroneous recognition of face expression of perseverative type (assimilative illusions). Plasticity of the set raises in 7-8-year age and considerably the number of assimilative illusions decreases. On 10-11 years sets doesn't differ essentially from adult people on plasticity and a ratio of number of assimilative and contrast illusions. Changes of spatial synchronization of electric potentials teta- and alpha ranges of frequencies in all age groups it is observed generally at a stage of formation of set. On all age groups strong correlation between bioelectric data and features of the set on a face expression is revealed. These data supports the hypothesis that cortiko-hippocampal and fronto-thalamic functional systems of integration of a brain activity participate in the organization of a set on an emotional face expression and provide cognitive flexibility.

[Theta and alpha-band EEG spatial synchronization under the conditions of visual set, formed to an angry face expression. A study of 5-11-year-old children].

EEG coherence in theta and alpha bands during set-forming and set-shifting was studied in 5-6-year-old (n=18) and 10-11-year-old (n=25) children. Set was formed to visual stimuli (facial photos with emotionally negative expression). Younger children displayed smaller coherence values, especially in the right hemisphere, than older ones. We also revealed differences in theta and alpha band coherence in cases of a rigid and a plastic set. For example, EEG-coherence values were smaller when cognitive processes were relatively rigid (i.e., in a case of a slower set-shifting). A strong correlation between electrophysiological and behavioral data supports the hypothesis that cortico-hippocampal and fronto-thalamic brain integration systems participate in facial expression recognition and provide cognition flexibility.

[Cognitive control in recognition of emotionally negative face in 5-10-year-old children].

We used the experimental model of cognitive visual set, designed by D.N. Uznadze, to study the influence of previous experience on emotional face expression recognition in pre-school (6.1 +/- 0.3 years) and elementary school (10.5 +/- 0.1 years) children. Our results suggest that the ability to form a cognitive set to an angry face expression develops in ontogenesis in strong concordance with functional maturation of prefrontal cortex that takes place at the age of approximately 10 years. At this age children display almost the same level of set plasticity and a similar kind of erroneous perceptions during set actualization as grown-ups. Children of younger age (6.1 +/- 0.3 years) display more perceverative erroneous perceptions, or assimilative illusions (probably of a priming origin), than the above mentioned groups. We consider this to be a result of a more strong influence of previous experience in their case.

Phonons of the anomalous element cerium.

Many physical and chemical properties of the light rare-earths and actinides are governed by the active role of f electrons, and despite intensive efforts the details of the mechanisms of phase stability and transformation are not fully understood. A prominent example which has attracted a lot of interest, both experimentally and theoretically over the years is the isostructural γ - α transition in cerium. We have determined by inelastic X-ray scattering, the complete phonon dispersion scheme of elemental cerium across the γ → α transition, and compared it with theoretical results using ab initio lattice dynamics. Several phonon branches show strong changes in the dispersion shape, indicating large modifications in the interactions between phonons and conduction electrons. This is reflected as well by the lattice Grüneisen parameters, particularly around the X point. We derive a vibrational entropy change ΔS(γ-α)(vib) ≈ (0.33+/-0.03)k(B), illustrating the importance of the lattice contribution to the transition. Additionally, we compare first principles calculations with the experiments to shed light on the mechanism underlying the isostructural volume collapse in cerium under pressure.