Changes In Lymphocyte Numbers Research Articles

Immune-Ageing Evaluation of Peripheral T and NK Lymphocyte Subsets in Chinese Healthy Adults

Ageing is often accompanied with a decline in immune system function, resulting in immune ageing. Numerous studies have focussed on the changes in different lymphocyte subsets in diseases and immunosenescence. The change in immune phenotype is a key indication of the diseased or healthy status. However, the changes in lymphocyte number and phenotype brought about by ageing have not been comprehensively analysed. Here, we analysed T and natural killer (NK) cell subsets, the phenotype and cell differentiation states in 43,096 healthy individuals, aged 20–88 years, without known diseases. Thirty-six immune parameters were analysed and the reference ranges of these subsets were established in different age groups divided into 5-year intervals. The data were subjected to random forest machine learning for immune-ageing modelling and confirmed using the neural network analysis. Our initial analysis and machine modelling prediction showed that naïve T cells decreased with ageing, whereas central memory T cells (Tcm) and effector memory T cells (Tem) increased cluster of differentiation (CD) 28-associated T cells. This is the largest study to investigate the correlation between age and immune cell function in a Chinese population, and provides insightful differences, suggesting that healthy adults might be considerably influenced by age and sex. The age of a person's immune system might be different from their chronological age. Our immune-ageing modelling study is one of the largest studies to provide insights into ‘immune-age’ rather than ‘biological-age’. Through machine learning, we identified immune factors influencing the most through ageing and built a model for immune-ageing prediction. Our research not only reveals the impact of age on immune parameter differences within the Chinese population, but also provides new insights for monitoring and preventing some diseases in clinical practice.

Single-cell RNA sequencing reveals immunological rewiring at the maternal-fetal interface following asymptomatic/mild SARS-CoV-2 infection.

While severe coronavirus 2019 (COVID-19) is associated with immune activation at the maternal-fetal interface, responses to asymptomatic/mild severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy remain unknown. Here, we assess immunological adaptations in blood and term decidua in response to asymptomatic/mild disease in pregnant women. We report attenuated antigen presentation and type I interferon (IFN) signaling pathways, loss of tissue-resident decidual macrophages, and upregulated cytokine/chemokine signaling in monocyte-derived decidual macrophages. Furthermore, we describe increased frequencies of activated tissue-resident T cells and decreased abundance of regulatory T cells with infection while frequencies of cytotoxic CD4/CD8 T cells are increased in the blood. In contrast to decidual macrophages, type I IFN signaling is higher in decidual T cells. Finally, infection leads to a narrowing of T cell receptor diversity in both blood and decidua. Collectively, these observations indicate that asymptomatic/mild COVID-19 during pregnancy results in remodeling of the immunological landscape of the maternal-fetal interface, with a potential for long-term adverse outcomes for the offspring.

Immunological efficiency of microbial melanin on bacterial pathogenicity.

In our present study, the immunological efficiency of brown Mel1 extracted from Streptomyces longisporoflavus NR043926 and black Mel2 extracted from Aspergillus niger MT355517 on bacterial pathogenicity was investigated. Mel1 and Mel2 were extracted and purified from the dried microbial biomass. Chemical characterization of extracted MeI pigments were compared with standard melanin. In vivo, estimation of the protective action of these pigments against Escherichia coli infection in Swiss albino mice which was identified by molecular characterizations 16S rRNA gene sequences, Albumin content was reduced in +ve control group (infected non – treated mice), while liver enzymes (ALT & AST) were increased in comparison to normal values were detected in immunized mice with Mel pigments. Eosinophil, monocyte values showed a non-difference, while the changes in lymphocyte numbers were paralleled to the response of total leukocyte counts. Serum antibodies total IgM in the non-immunized (+ve control group) mice were markedly lower than those observed in immunized mice (prevention groups and treated groups) with microbial melanin which can stimulate immunity system. Mel2 had high immunoprotection defense against E. coli infection in comparison to Mel1.

Immune cell and transcriptomic analysis of the human decidua in term and preterm parturition

STUDY QUESTIONIs labour, both at term and preterm, associated with alterations in decidual lymphocyte densities and widespread changes to the decidual transcriptome?SUMMARY ANSWERThe onset of parturition, both at term and preterm, is associated with widespread gene expression changes in the decidua, many of which are related to inflammatory signalling, but is not associated with changes in the number of any of the decidual lymphocyte populations examined.WHAT IS KNOWN ALREADYGiven its location, directly at the maternal–foetal interface, the decidua is likely to play a pivotal role in the onset of parturition, however, the molecular events occurring in the decidua in association with the onset of labour, both at term and preterm, remain relatively poorly defined. Using flow cytometry and microarray analysis, the present study aimed to investigate changes to the immune cell milieu of the decidua in association with the onset of parturition and define the decidual gene signature associated with term and preterm labour (PTL).STUDY DESIGN, SIZE, DURATIONThis study used decidual samples collected from 36 women across four clinical groups: term (38–42 weeks of gestation) not in labour, TNL; term in labour, TL; preterm (<35 weeks of gestation)not in labour, PTNL; and preterm in labour, PTL.PARTICIPANTS/MATERIALS, SETTING, METHODSDecidual lymphocytes were isolated from fresh decidual tissue collected from women in each of our four patient groups and stained with a panel of antibodies (CD45, CD3, CD19, CD56, CD4, CD8 and TCRVα24-Jα18) to investigate lymphocyte populations present in the decidua (TNL, n = 8; TL, n = 7; PTNL, n = 5; PTL, n = 5). RNA was extracted from decidual tissue and subjected to Illumina HT-12v4.0 BeadChip expression microarrays (TNL, n = 11; TL, n = 8; PTNL, n = 7; PTL, n = 10). Quantitative real-time PCR (qRT-PCR) was used to validate the microarray results.MAIN RESULTS AND THE ROLE OF CHANCEThe relative proportions of decidual lymphocytes (T cells, NK cells, B cells and invariant natural killer (iNKT) cells) were unaffected by either gestation or labour status. However, we found elevated expression of the non-classical MHC-protein, CD1D, in PTL decidua samples (P < 0.05), suggesting the potential for increased activation of decidual invariant NKT (iNKT) cells in PTL. Both term and PTL were associated with widespread gene expression changes, particularly related to inflammatory signalling. Up-regulation of candidate genes in TL (IL-6, PTGS2, ATF3, IER3 and TNFAIP3) and PTL (CXCL8, MARCO, LILRA3 and PLAU) were confirmed by qRT-PCR analysis.LARGE SCALE DATAMicroarray data are available at www.ebi.ac.uk/arrayexpress under accession number E-MTAB-5353.LIMITATIONS REASONS FOR CAUTIONWhilst no changes in lymphocyte number were observed across our patient samples, we did not investigate the activation state of any of the immune cell sub-populations examined, therefore, it is possible that the function of these cells may be altered in association with labour onset. Additionally, the results of our transcriptomic analyses are descriptive and at this stage, we cannot prove direct causal link with the up-regulation of any of the genes examined and the onset of either term or PTL.WIDER IMPLICATIONS OF THE FINDINGSOur findings demonstrate that the onset of parturition is associated with widespread changes to the decidual transcriptome, and there are distinct gene expression changes associated with term and PTL. We confirmed that an inflammatory signature is present within the decidua, and we also report the up-regulation of several genes involved in regulating the inflammatory response. The identification of genes involved in regulating the inflammatory response may provide novel molecular targets for the development of new, more effective therapies for the prevention of preterm birth (PTB). Such targets are urgently required.STUDY FUNDING AND COMPETING INTEREST(S)This work was supported by Medical Research Council (grant number MR/L002657/1) and Tommy's, the baby charity. Jane Norman has had research grants from the charity Tommy's and from the National Institute for Health Research on PTB during the lifetime of this project. Jane Norman also sits on a data monitoring committee for GSK for a study on PTB prevention and her institution receives financial recompense for this. The other authors do not have any conflicts of interest to declare.

Acute relapse after initiation of Siponimod in a patient with secondary progressive MS.

Sphingosine 1-phosphate (S1P) is a signaling molecule that binds to five G protein-coupled receptors (Proc Natl Acad Sci USA 108:751-756, 2011). Modulation of these receptors has been associated with pleiotropic biological effects in the immune, cardiovascular, and central nervous systems (CNS). The functional S1P receptor antagonist fingolimod was the first member of this class of pharmacotherapeutics to be approved for treatment of relapsing multiple sclerosis (MS). Siponimod is currently in clinical trial in patients with secondary progressive (SP) MS, a clinical trial for which there is an unmet need for disease-modifying agents. 10 weeks into the trial, the patient awoke with blurry vision in his left eye, and was subsequently diagnosed with an acute optic neuritis. Despite discontinuation of siponimod and treatment with pulse corticosteroids, the patient did not regain visual function in the affected eye. This is the first report of disease reactivation shortly after initiating siponimod in a patient with SPMS. This case illustrates that the known changes in lymphocyte numbers and composition in the CNS associated with S1P receptor antagonism during the SPMS disease stage may have adverse outcomes in some patients during treatment initiation, and that close clinical and paraclinical monitoring is advised.

Abstract 9852: T Lymphocyte Depletion Following Primary Percutaneous Coronary Intervention Predicts Infarct Size and Ischemia Reperfusion Injury

Background: We have previously demonstrated acute changes in lymphocyte numbers in peripheral blood following reperfusion with primary percutaneous coronary intervention (PPCI) for STEMI. The goal of this study was to investigate a potential role for T cells in ischemia reperfusion (I/R) injury. Methods: We analyzed blood from 22 STEMI patients undergoing PPCI. Blood was taken at the start of the procedure, and at 15, 30, 90 minutes, and 24 hours post reperfusion. In 5 patients with infarcts due to LAD occlusion, coronary sinus (CS) blood was also obtained 30-60min after reperfusion along with simultaneous aortic blood. 8-colour flow cytometric analysis was performed on the fresh blood to quantify lymphocyte populations. Cardiac MRI was performed at 1-7 days, and left ventricular ejection fraction, infarct size (measured by late gadolinium enhancement), microvascular obstruction (MVO), area at risk and salvage index quantified. Results: T-lymphocytes dropped between 0 and 90 minutes by a mean of 42% (0min mean 1767/μl, 90min 931/μl), CD4 T-helper cells by 31%, and CD8 cytotoxic T-cells by 55%. The change in total T-cells correlated with infarct size (r=-0.78, p&lt;0.001), as did that of CD4 (r=-0.66, p&lt;0.01) and CD8 T cells (r=-0.76, p&lt;0.001). The T cell drop between 0 and 90 minutes also correlated strongly with MVO (r=-0.72, p&lt;0.01), as did the CD4 (r=-0.66, p&lt;0.01) and CD8 T cell drop (r=-0.77, p&lt;0.001). Myocardial salvage index correlated strongly with the change in T cells (r=0.85, p&lt;0.001), CD4 T cells (r=0.76, p&lt;0.01) and CD8 T cells (r=0.76, p&lt;0.01) between 30 and 90 minutes. Prior to reperfusion 6.4% of CD8 T cells were activated (CD69+), with progressive loss of CD69+ cells after 90 minutes (4.3%) and 24 hours (2.6%, 0min vs 24hr p&lt;0.01). However, CS sampling showed an increase in CD69 expression between aortic and CS blood, suggesting activation of T cells as they pass through the myocardial vascular bed. Conclusion: Acute changes in T lymphocyte numbers following reperfusion after PPCI predict infarct size, MVO, and salvage index. The drop in these cells following reperfusion, and the dynamics of CD69 expression, suggest a potential role for CD69+ activated T cells in I/R injury. This requires further investigation and may represent a novel therapeutic target.

Latent Microsporidiosis Caused by Encephalitozoon cuniculi in Immunocompetent Hosts: A Murine Model Demonstrating the Ineffectiveness of the Immune System and Treatment with Albendazole

BackgroundMicrosporidia are obligate intracellular parasites causing severe infections with lethal outcome in immunocompromised hosts. However, these pathogens are more frequently reported as latent infections in immunocompetent individuals and raises questions about the potential risk of reactivation following induced immunosuppression.AimsTo evaluate the possibility latent microsporidiosis, efficacy or albendazole, and reactivation, the authors monitored the course of E. cuniculi infection in immunocompetent BALB/c mice and immunodeficient SCID mice using molecular methods.MethodsMice were per orally infected with 107 spores of E. cuniculi. Selected groups were treated with albendazole, re-infected or chemically immunosuppressed by dexamethasone. The presence of microsporidia in the host’s organs and feces were determined using PCR methods. Changes in numbers of lymphocytes in blood and in spleen after induction of immunosuppression were confirmed using flow cytometry analysis.ResultsWhereas E. cuniculi caused lethal microsporidiosis in SCID mice, the infection in BABL/c mice remained asymptomatic despite parasite dissemination into many organs during the acute infection phase. Albendazole treatment led to microsporidia elimination from organs in BALB/c mice. In SCID mice, however, only a temporary reduction in number of affected organs was observed and infection re-established post-treatment. Dexamethasone treatment resulted in a chronic microsporidia infection disseminating into most organs in BALB/c mice. Although the presence of E. cuniculi in organs of albendazole- treated mice was undetectable by PCR, it was striking that infection was reactivated by immunosuppression treatment.ConclusionOur results demonstrated that microsporidia can successfully survive in organs of immunocompetent hosts and are able to reactivate from undetectable levels and spread within these hosts after induction of immunosuppression. These findings stress the danger of latent microsporidiosis as a life-threatening risk factor especially for individuals undergoing chemotherapy and in transplant recipients of organs originating from infected donors.

Brain Irradiation-Induced Lymphocytosis Predicts Response in Cancer Patients with Brain Metastases

Lymphocytopenia is one of the main toxicities of radiotherapy and its severity is related to the irradiation dose. The occurrence of lymphocytopenia depends on the body site of radiotherapy; it is most pronounced with pelvic irradiation, whereas the effect of brain irradiation on the lymphocyte count is to be elucidated. This preliminary study was performed to evaluate changes in lymphocyte number occurring during brain irradiation in cancer patients with brain metastases. The study included 50 patients who received brain radiotherapy for single or multiple brain metastases at a total dose of 30 Gy. Overall, no significant changes in mean lymphocyte number occurred during brain radiotherapy. However, when lymphocyte variations were assessed in relation to the clinical response of brain metastases, a significant increase in the mean number of lymphocytes was found in patients who achieved objective regression of brain metastases on brain irradiation. The mean lymphocyte number decreased in nonresponding patients, albeit without a statistically significant difference with respect to the pretreatment values. The results of this study show that the efficacy of radiotherapy in the treatment of brain metastases is associated with a significant increase in mean lymphocyte number. Therefore, evidence of brain irradiation-induced lymphocytosis may predict the efficacy of radiotherapy.

Brain irradiation-induced lymphocytosis predicts response in cancer patients with brain metastases

Lymphocytopenia is one of the main toxicities of radiotherapy and its severity is related to the irradiation dose. The occurrence of lymphocytopenia depends on the body site of radiotherapy; it is most pronounced with pelvic irradiation, whereas the effect of brain irradiation on the lymphocyte count is to be elucidated. This preliminary study was performed to evaluate changes in lymphocyte number occurring during brain irradiation in cancer patients with brain metastases. The study included 50 patients who received brain radiotherapy for single or multiple brain metastases at a total dose of 30 Gy. Overall, no significant changes in mean lymphocyte number occurred during brain radiotherapy. However, when lymphocyte variations were assessed in relation to the clinical response of brain metastases, a significant increase in the mean number of lymphocytes was found in patients who achieved objective regression of brain metastases on brain irradiation. The mean lymphocyte number decreased in nonresponding patients, albeit without a statistically significant difference with respect to the pretreatment values. The results of this study show that the efficacy of radiotherapy in the treatment of brain metastases is associated with a significant increase in mean lymphocyte number. Therefore, evidence of brain irradiation-induced lymphocytosis may predict the efficacy of radiotherapy.

Sleep deprivation reduces the lymphocyte count in a non-obese mouse model of type 1 diabetes mellitus

The objective of the present study was to determine whether sleep deprivation (SD) would promote changes in lymphocyte numbers in a type 1 diabetes model (non-obese diabetic, NOD, mouse strain) and to determine whether SD would affect female and male NOD compared to Swiss mice. The number of lymphocytes in peripheral blood after 24 and 96 h of SD (by multiple platform method) or equivalent period of time in home-cage controls was examined prior to the onset of diabetes. SD for 96 h significantly reduced lymphocytes in male Swiss mice compared to control (8.6 ± 2.1 vs 4.1 ± 0.7 10³/µL; P < 0.02). In male NOD animals, 24- and 96-h SD caused a significant decrease of lymphocytes compared to control (4.4 ± 0.3 vs 1.6 ± 0.5; P < 0.001 and 4.4 ± 0.3 vs 0.9 ± 0.1 10³/µL; P < 0.00001, respectively). Both 24- and 96-h SD induced a reduction in the number of lymphocytes in female Swiss (7.5 ± 0.5 vs 4.5 ± 0.5, 4.4 ± 0.6 10³/µL; P < 0.001, respectively) and NOD mice (4 ± 0.6 vs 1.8 ± 0.2, 1.2 ± 0.4 10³/µL; P < 0.01, respectively) compared to the respective controls. Loss of sleep induced lymphopenia in peripheral blood in both genders and strains used. Since many cases of autoimmunity present reduced numbers of lymphocytes and, in this study, it was more evident in the NOD strain, our results suggest that SD should be considered a risk factor in the onset of autoimmune disorders.

Sleep deprivation reduces the lymphocyte count in a non-obese mouse model of type 1 diabetes mellitus

The objective of the present study was to determine whether sleep deprivation (SD) would promote changes in lymphocyte numbers in a type 1 diabetes model (non-obese diabetic, NOD, mouse strain) and to determine whether SD would affect female and male NOD compared to Swiss mice. The number of lymphocytes in peripheral blood after 24 and 96 h of SD (by multiple platform method) or equivalent period of time in home-cage controls was examined prior to the onset of diabetes. SD for 96 h significantly reduced lymphocytes in male Swiss mice compared to control (8.6 +/- 2.1 vs 4.1 +/- 0.7 10(3)/microL; P < 0.02). In male NOD animals, 24- and 96-h SD caused a significant decrease of lymphocytes compared to control (4.4 +/- 0.3 vs 1.6 +/- 0.5; P < 0.001 and 4.4 +/- 0.3 vs 0.9 +/- 0.1 10(3)/microL; P < 0.00001, respectively). Both 24- and 96-h SD induced a reduction in the number of lymphocytes in female Swiss (7.5 +/- 0.5 vs 4.5 +/- 0.5, 4.4 +/- 0.6 10(3)/microL; P < 0.001, respectively) and NOD mice (4 +/- 0.6 vs 1.8 +/- 0.2, 1.2 +/- 0.4 10(3)/microL; P < 0.01, respectively) compared to the respective controls. Loss of sleep induced lymphopenia in peripheral blood in both genders and strains used. Since many cases of autoimmunity present reduced numbers of lymphocytes and, in this study, it was more evident in the NOD strain, our results suggest that SD should be considered a risk factor in the onset of autoimmune disorders.

Acute Depletion and Recovery of Peritoneal B-1 Lymphocytes in BALB/c Mice after a Single Injection of Mercury Chloride

The acute toxicity of mercury (Hg) to B cells was studied in the peritoneal cavity of BALB/c mice, a coelomic space where both B-1 and B-2 subsets of B lymphocytes are present. Up to 24 hr after a single in situ Hg injection, the peritoneal cavity became virtually devoid of lymphocytes, particularly of the B-1 subset. Lymphocyte depletion was more severe for B than T cells. This depletion was associated with partial lymphocyte activation (CD69+) at 6 hr of treatment and it was due to apoptosis rather than to necrosis. Partial recovery of both B and T cells was observed in the peritoneal cavity 48 hr after the Hg injection. The phenomenon was followed by a second decrease in peritoneal lymphocytes 72 hr after Hg. Neutrophils that entered the peritoneal cavity because of the Hg injection were resistant to apoptosis. No significant changes in lymphocyte number or subpopulation were found in the spleen and thymus of the mice up to 72 hr after the Hg treatment. We concluded that B lymphocytes were severely affected by the toxic effects of Hg. Our data suggest that Hg-induced unbalance in the repertoire of B cells, of the B-1 subset in particular, may result later in the secretion of the high titres of pathogenic autoantibodies that are found in the Hg-induced lupus disorder of BALB/c mice.

Lymphocyte Apoptosis, Adhesion/activation Molecules And Complement Regulatory Proteins Following Intensive, Moderate And Eccentric Exercise

Exercise elicits an initial increase in the number of blood lymphocytes, followed by a rapid lymphocytopenia in the recovery phase. Alterations in cell phenotype accompany changes in lymphocyte number. The mechanisms underlying these changes and their potential functional consequences are not understood. PURPOSE To examine the effects of intensive, moderate and eccentric exercise on lymphocyte apoptosis, and lymphocyte expression of the complement regulatory proteins CD55 (DAF) and CD59 (MACIF), and the adhesion/activation molecules CD18 (β2 integrin), CD53 and CD54 (ICAM-1). METHODS Eight trained males (Age: 28 ± 5 yrs,: VO2max 63 ± 3 ml-kg·min−1) completed three treadmill running protocols: (1) an intensive protocol at 80% VO2max, (2) a moderate protocol at 60% VO2max, and (3) a −10% eccentric protocol at 80% VO2max. Blood samples were taken before exercise, immediately after, 1h and 24h later. Isolated lymphocytes were assessed for markers of apoptosis (Annexin-V, HSP60 and CD95) and expression of CD proteins using flow cytometry. RESULTS No lymphocyte apoptosis was found after any of the running protocols. Using CD55, CD59, CD18 and CD53 monoclonal antibodies, two populations of lymphocytes with strikingly different fluorescent intensities (“dim” or “bright”) were found. Together these accounted for >98% of lymphocytes. An increase in the percentage of CD55dim, CD59dim, CD18bright, CD53bright and CD54+ cells occurred immediately after the intensive protocol, before falling below baseline at 1h post-exercise (p<0.05). The phenotypes of lymphocytes at 24hr closely resembled those found pre-exercise. The eccentric protocol at the same relative intensity produced similar results. No significant changes in lymphocyte phenotype were observed following the moderate protocol (p>0.05). Two-colour analysis of lymphocyte subsets showed that increases in CD8+ T-lymphocytes and CD3−/CD56+ Natural Killer (NK) cells immediately after the intensive protocol, and their subsequent fall within 1 hr account for the changes in CD55dim, CD59dim, CD18bright CD53bright and CD54+ populations. No changes in CD4+ T-lymphocytes were found. CONCLUSION Apoptosis affecting blood lymphocytes does not contribute to post-exercise lymphocytopenia. Intensive treadmill running results in the appearance in the blood of additional CD8+ T lymphocytes and CD3−/CD56+NK cells. Lymphocytes expressing high levels of cell surface adhesion/activation molecules appear to exit the blood within 1h post exercise. The basis of selection of lymphocyte subsets for recruitment into the blood, and their fate after exercise-induced extravasation requires investigation.

Lymphocyte Apoptosis, Adhesion/activation Molecules And Complement Regulatory Proteins Following Intensive, Moderate And Eccentric Exercise

Exercise elicits an initial increase in the number of blood lymphocytes, followed by a rapid lymphocytopenia in the recovery phase. Alterations in cell phenotype accompany changes in lymphocyte number. The mechanisms underlying these changes and their potential functional consequences are not understood. PURPOSE To examine the effects of intensive, moderate and eccentric exercise on lymphocyte apoptosis, and lymphocyte expression of the complement regulatory proteins CD55 (DAF) and CD59 (MACIF), and the adhesion/activation molecules CD18 (β2 integrin), CD53 and CD54 (ICAM-1). METHODS Eight trained males (Age: 28 ± 5 yrs,: VO2max 63 ± 3 ml-kg·min−1) completed three treadmill running protocols: (1) an intensive protocol at 80% VO2max, (2) a moderate protocol at 60% VO2max, and (3) a −10% eccentric protocol at 80% VO2max. Blood samples were taken before exercise, immediately after, 1h and 24h later. Isolated lymphocytes were assessed for markers of apoptosis (Annexin-V, HSP60 and CD95) and expression of CD proteins using flow cytometry. RESULTS No lymphocyte apoptosis was found after any of the running protocols. Using CD55, CD59, CD18 and CD53 monoclonal antibodies, two populations of lymphocytes with strikingly different fluorescent intensities (“dim” or “bright”) were found. Together these accounted for >98% of lymphocytes. An increase in the percentage of CD55dim, CD59dim, CD18bright, CD53bright and CD54+ cells occurred immediately after the intensive protocol, before falling below baseline at 1h post-exercise (p<0.05). The phenotypes of lymphocytes at 24hr closely resembled those found pre-exercise. The eccentric protocol at the same relative intensity produced similar results. No significant changes in lymphocyte phenotype were observed following the moderate protocol (p>0.05). Two-colour analysis of lymphocyte subsets showed that increases in CD8+ T-lymphocytes and CD3−/CD56+ Natural Killer (NK) cells immediately after the intensive protocol, and their subsequent fall within 1 hr account for the changes in CD55dim, CD59dim, CD18bright CD53bright and CD54+ populations. No changes in CD4+ T-lymphocytes were found. CONCLUSION Apoptosis affecting blood lymphocytes does not contribute to post-exercise lymphocytopenia. Intensive treadmill running results in the appearance in the blood of additional CD8+ T lymphocytes and CD3−/CD56+NK cells. Lymphocytes expressing high levels of cell surface adhesion/activation molecules appear to exit the blood within 1h post exercise. The basis of selection of lymphocyte subsets for recruitment into the blood, and their fate after exercise-induced extravasation requires investigation.

Measles: immune suppression and immune responses

Measles is a highly contagious viral disease that remains the leading vaccine-preventable cause of child mortality worldwide. Deaths from measles are due largely to an increased susceptibility to secondary bacterial and viral infections, attributed to a prolonged state of immune suppression. Several abnormalities of the immune system have been described, including changes in lymphocyte number and function, shifts in cytokine responses, immunomodulatory effects of interleukin-10, down regulation of interleukin-12, impaired antigen presentation, and altered interferon α/β signaling pathways. Although the current vaccine is very effective, knowledge of the molecular basis of the immune responses to measles virus could contribute to the development of a safer, more immunogenic measles vaccine. However, the safety of new measles vaccines must be carefully investigated, as two measles vaccines have resulted in unintended immunologic consequences: atypical measles following administration of the formalin-inactivated measles vaccine and increased mortality in girls following administration of high-titer measles vaccines.

Measles: immune suppression and immune responses

Measles is a highly contagious viral disease that remains the leading vaccine-preventable cause of child mortality worldwide. Deaths from measles are due largely to an increased susceptibility to secondary bacterial and viral infections, attributed to a prolonged state of immune suppression. Several abnormalities of the immune system have been described, including changes in lymphocyte number and function, shifts in cytokine responses, immunomodulatory effects of interleukin-10, down regulation of interleukin-12, impaired antigen presentation, and altered interferon α/β signaling pathways. Although the current vaccine is very effective, knowledge of the molecular basis of the immune responses to measles virus could contribute to the development of a safer, more immunogenic measles vaccine. However, the safety of new measles vaccines must be carefully investigated, as two measles vaccines have resulted in unintended immunologic consequences: atypical measles following administration of the formalin-inactivated measles vaccine and increased mortality in girls following administration of high-titer measles vaccines.

Mechanisms of changes in lymphocyte numbers after psychological stress.

In the field of psychoneuroimmunology it has become obvious that the immune system is governed by multiple influences from the central nervous system. One approach to verify these interactions can be seen in stress research. While the phenomenon of stress-induced changes in immunological processes is widely accepted, more recent studies focus on possible moderators and mechanisms of these responses. Within this research strategy it became evident that catecholamine increases upon stress are of major importance for the frequently observed mild leukocytosis. The present study was conducted to investigate whether the often observed stress-induced increases in the number of peripheral lymphocyte subsets depends on the amount of epinephrine or norepinephrine release. Moreover, the question was addressed whether high or low catecholamine release is related to subjective ratings on discomfort. Using a "public speaking paradigm", we were able to replicate previous findings of high increases in the absolute number of CD8+ and CD56+ cells in peripheral blood. Moreover, when dividing subjects into high and low catecholamine responders, the amount of change was significantly larger in catecholamine responders irrespective of whether norepinephrine or epinephrine was used for grouping the subjects. However, high and low catecholamine responders did not differ with respect to subjective ratings on discomfort. The data are discussed with respect to underlying mechanisms in catecholamine-induced lymphocyte migration and possible reasons for the mismatch between objective and subjective indicators of stressor efficacy.

Pretreatment serum markers and lymphocyte response to interleukin-2 therapy

Lymphocytosis is a marker of subcutaneous interleukin (IL)-2 therapy efficacy, whereas baseline elevated inflammatory indices were noticed in IL-2-resistant disease. The aim of this study was to analyse the relationship between pretreatment circulating values of IL-6, neopterin, sIL-2R, ESR and the changes in lymphocyte number in response to IL-2 administration. Twenty metastatic renal cell cancer patients were treated with subcutaneous IL-2 immunotherapy (6 000 000 IU day−1 for 6 days per week for 4 weeks); tumour response consisted of partial response (PR) in four patients, stable disease (SD) in eight patients and progressive disease (PD) in eight patients. Abnormally high pretreatment values of each marker were found as follows: IL-6 in seven patients, neopterin in nine patients, sIL-2R in 13 patients. In response to IL-2 immunotherapy, a significantly higher mean increase in lymphocyte number and a higher percentage of patients with tumour response or stable disease were observed when pretreatment values of IL-6, neopterin and sIL-2R were within the normal range, in comparison to patients with high values for these markers. The pretreatment excess of these serum inflammatory markers seems to negatively influence both the host and tumour response to IL-2 administration, by preventing the IL-2-induced lymphocytosis and resulting in tumour progression. Further studies are requested to verify if overall survival and quality of life may depend on pretreatment host immune status and/or lymphocyte response after IL-2 administration. © 1999 Cancer Research Campaign

Changes in Lymphocyte Number during Cancer Chemotherapy and Their Relation to Clinical Response

Since hematologic examination during cancer chemotherapy is generally limited to the evaluation of neutrophil and platelet numbers, at present there are no clear data about the possible prognostic significance of changes in lymphocyte number in relation to the clinical efficacy of chemotherapy itself. To obtain some preliminary data about this issue, we have evaluated changes in lymphocyte number and percentage in a group of 50 advanced non-small cell lung cancer patients treated with three cycles of cisplatin (20 mg/m2/day) plus etoposide (100 mg/m2/day) i.v. for three days every 21 days. The clinical response consisted of partial response (PR) in nine (18%), stable disease (SD) in 18 (36%) and progressive disease (PD) in the remaining 23 (46%) patients. The lymphocyte percentage increased during chemotherapy, without, however, a significant difference with respect to the pretreatment values. In contrast, the mean number of lymphocytes observed after the first chemotherapeutic cycle significantly decreased in patients with PD, whereas it increased in patients with PR or SD, even though the difference did not reach statistical significance. These preliminary data, which have to be confirmed in a large number of patients and in patients treated with other chemotherapeutic schedules for different tumor types, seem to suggest that a chemotherapy-induced decline in lymphocyte number may be associated with a lack of efficacy of chemotherapy itself.

Basophils and eosinophils in allergic rhinitis

and HLA-DR positivity in the dermis. Arthritis Rheum 1988;31:672-7. 60. Seibold JR, Giorno RC, Claman HN. Dermal mast cell degranulation in systemic sclerosis. Arthritis Rheum 1990; 33:1702-9. 61. Chanez P, Lacoste J-Y, Guillot B, et al. Mast cells' contribution to the fibrosing alveolitis of the scleroderma lung. Am Rev Resp Dis 1993;147:1497-502. 62. de Paulis A, Valentini G, Spadaro G, Lupoli S, Tirri G, Marone G. Human basophil releasability. VIII. Increased basophil releasability in patients with scleroderma. Arthritis Rheum 1991;34:1289-96. 63. Kaufman LD, Gruber BL, Marchese M J, Seibold JR. Anti-IgE autoantibodies in systemic sclerosis (scleroderma). Ann Rheum Dis 1989;48;201-5. 64. Valent P, Bettelheim P. Cell surface structures on human basophils and mast cells: biochemical and functional characterization. Adv Immunol 1992;52:333-423. 65. Columbo M, Horowitz EM, Botana LM, et al. The human recombinant c-kit receptor ligand, rhSCF, induces mediator release from human cutaneous mast cells and enhances IgE-dependent mediator release from both skin mast cell and peripheral blood basophils. J Immunol 1992;149:599-608. 66. de Paulis A, Ciccarelli A, Cirillo R, de Crescenzo G, Columbo M, Marone G. Modulation of human lung mast cell function by the c-kit receptor ligand. Int Arch Allergy Immunol 1992;99:326-9. 67. MacGlashan DW Jr, Hubbard WC. IL-3 alters free arachidonic acid generation in C5a-stimulated human basophils. J Immunol 1993;151:6358-69. 68. Cirillo R, Triggiani M, Siri L, et al. Cyclosporin A rapidly inhibits mediator release from human basophils presumably by interacting with cyclophilin. J Immunol 1990;144: 3891-7. 69. de Paulis A, Ciccarelli A, Cirillo R, de Crescenzo G, Columbo M, Marone G. Cytokine-induced modulation of human Fc,RI + inflammatory cells. In: Romagnani S, Mosmann TR, Abbas AK, eds. New advances on cytokines. New York: Raven Press, 1992:367-86. 70. Merget RD, Maurer AB, Koch U, et al. Histamine release from basophils after in vivo application of recombinant human interleukin-3 in man. Int Arch Allergy Appl Immunol 1990;92:366-74. 71. White MV, Igarashi Y, Emmery BE, Lotze MT, Kaliner MA. Effects of in vivo administration of interleukin-2 (IL-2) and IL-4, alone and in combination, on ex vivo human basophil histamine release. Blood 1992;76:1491-5.