Blood Leukocyte Composition Research Articles

Effect of long-term emotional-painful stress on the leukocyte composition of blood in rats with different levels of excitability of the nervous system

Post-stress states in animals and humans are accompanied by the development of neuro- and peripheral inflammation. The mechanisms of such immune dysfunctions, their contribution to the pathogenesis of stress-related diseases, as well as the dependence of the intensity of poststress inflammation on genetically determined features of the nervous system, have not been clarified.
 Aim: to assess the dynamics of the development of poststress inflammation depending on the genetically determined level of excitability of the nervous system in rats.
 Materials and methods. The study was carried out on male rats of two lines, selected by the threshold of excitability of the nervous system-the line HT (high threshold of excitability) and LT (low threshold of excitability). As a model of chronic stress, the Protocol of long-term emotional and pain exposure according to Hecht was used. To investigate the dynamics of changes in the leukocyte formula, three time points were selected: 24 hours, 7 days and 24 days after the stressor. Morphological analysis of blood was carried out to determine the leukogram, for which the leukocytes were counted in a blood smear stained by Romanovsky-Gimza.
 Results. Chronic stress leads to an increase in the leukocyte shift index only in the experimental group of highly excitable rats of the LT line compared with control animals of the same line. The significance of the differences is confirmed on day 7 after the end of the stressor. No interline differences in neutrophil/lymphocyte ratios were found in intact animals of LT and HT lines.
 Conclusion. In rats with a genetically determined high level of excitability of the nervous system, post-stressor systemic inflammation appears 7 days after the end of the stressor. Animals with a low level of excitability of the nervous system had no signs of post-stress inflammation throughout the observations. The article discusses the possible mechanisms of detected immune dysfunctions in animals due to high excitability of the central nervous system.

Leukocyte populations and their cell adhesion molecules expression in newborn dromedary camel calves.

Background and Aim:Different properties of the newborn immune system have been characterized in many species. For the newborn camel calf, however, the phenotype and composition of blood leukocytes have so far not been evaluated. The current study aimed to analyze the distribution of leukocyte subpopulations and their expression pattern of cell adhesion molecules in newborn and adult dromedary camels.Materials and Methods:Blood samples were collected from 17 newborn camel calves and 32 adult camels. For each sample, total leukocytes were separated and analyzed for their composition and cell adhesion molecules expression by flow cytometry.Results:In comparison to adult camels, newborn camel calves had higher leukocyte numbers and higher numbers of neutrophils, monocytes, and lymphocytes but lower numbers of eosinophils in their blood. Among the lymphocyte populations in calves, the fractions of B cells and γδ T cells were elevated when compared to adults, whereas CD4-positive T cells were reduced. The comparison between camel calves and adult camels revealed significantly lower expression of the cell adhesion molecules CD11a, CD11b, and CD18 on granulocytes, monocytes, and lymphocytes in calves.Conclusion:Newborn camel calves show a distinct composition and phenotype pattern of blood leukocytes when compared to adult camels. The observed rise in many leukocyte populations in calf blood may be due to reduced migratory activity in calf leukocyte populations.

Моделирование синдрома системного воспалительного ответа на анестезированных крысах

Systemic inflammation causes respiratory and circulatory dysfunctions. To study the mechanisms of these disorders, it is necessary to simulate the syndrome of systemic inflammatory response (SIRS) in an acute experiment on animals anesthetized with urethane. The aim of the present study was to test the hypothesis that one of the SIRS symptoms can be reproduced in these experimental conditions, namely — the change in the number and composition of blood leukocytes. The work was performed on laboratory rats (male Wistar, 250–300 grams) anesthetized with urethane (1600 mg/kg, i. p.) and divided into three groups. Animals of the first group (n = 5) underwent surgery simulating some surgical approaches used in the study of respiratory and circulatory functions. The second group (n = 5) was administered intravenously with 500 μg of bacterial lipopolysaccharide (LPS) dissolved in 1 ml of saline. In the third group (n = 5) the sham operation was combined with the introduction of LPS. Measurement of the number of white blood cells in blood samples taken from the caudal vein showed that the introduction of LPS in the second and third groups caused a decrease in the total number of white blood cells, mainly due to neutrophils. The obtained results prove that in an acute experiment in rats anesthetized with urethane, intravenous LPS can cause leucopenia, that is, reproduce one of the most important (along with tachycardia, tachypnea, and changes in body temperature) symptoms of SIRS.

Влияние инсульт-ассоциированной пневмонии на исход острого каротидного ишемического инсульта

Aim: to study the stroke-associated pneumonia (SAP) effect on the outcome of ischemic stroke (IS) in the internal carotid artery system. Patients and Methods: 87 patients with IS underwent the follow-up study, of which 75 had no inflammatory bronchopulmonary complications (group 1), and 12 had pneumonia manifestation (group 2). The study was performed on days 1, 5, and 9 after IS, and 6 months and 12 months after discharge from the hospital. Neurological deficit severity (NIHSS, Barthel index) and inflammatory markers (peripheral blood leukocyte composition, C-reactive protein (CRP), ESR) were studied. Results: it was found that the presence of SAP was associated with increased mortality during the acute IS period (4 (33.1%) patients died in group 1 and 10 (13.3%) — in group 2, p<0.05), greater severity of neurological deficits (63.3±5.3 and 71.5±4.0 points on the NIHSS scale, respectively, p<0.05) and incapacitation (Barthel index — 63.3±5.3 and 71.5±4.0 points, respectively, p<0.05) at the end of the inpatient treatment period. In group 2, signs of an inflammatory response were detected on day 5, and the values of the white blood cell shift index, ESR and CRP significantly (p<0.05) differed from the initial values. During examination at 6 months and 12 months, there were no significant differences in these indicators between the groups. An association was established between the probability of SAP occurrence and the presence of swallowing disorders (r=0.672; p<0.05), the age of patients (r=0.572; p<0.05) and the presence of diabetes mellitus (r=0.522; p<0.05). The studied laboratory inflammatory markers allow us to timely assume the occurrence of pulmonary pathology. Conclusion: timely diagnosis and prevention of SAP can reduce the risk of fatal outcome, facilitate rehabilitation measures, and improve early IS outcomes. KEYWORDS: ischemic stroke, cardioembolic stroke, atherothrombotic stroke, complications, acute period, inflammatory markers, strokeassociated pneumonia, long-term outcomes. FOR CITATION: Chipova D.T., Santikova L.V., Zhemukhov A.Ch. Impact of stroke-associated pneumonia on the outcome of acute ischemic stroke in internal carotid artery system. Russian Medical Inquiry. 2020;4(9):539–543. DOI: 10.32364/2587-6821-2020-4-9-539-543.

Cell-type-specific resolution epigenetics without the need for cell sorting or single-cell biology

High costs and technical limitations of cell sorting and single-cell techniques currently restrict the collection of large-scale, cell-type-specific DNA methylation data. This, in turn, impedes our ability to tackle key biological questions that pertain to variation within a population, such as identification of disease-associated genes at a cell-type-specific resolution. Here, we show mathematically and empirically that cell-type-specific methylation levels of an individual can be learned from its tissue-level bulk data, conceptually emulating the case where the individual has been profiled with a single-cell resolution and then signals were aggregated in each cell population separately. Provided with this unprecedented way to perform powerful large-scale epigenetic studies with cell-type-specific resolution, we revisit previous studies with tissue-level bulk methylation and reveal novel associations with leukocyte composition in blood and with rheumatoid arthritis. For the latter, we further show consistency with validation data collected from sorted leukocyte sub-types.

Methylomic profiles reveal sex-specific differences in leukocyte composition associated with post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is a debilitating mental disorder precipitated by trauma exposure. However, only some persons exposed to trauma develop PTSD. There are sex differences in risk; twice as many women as men develop a lifetime diagnosis of PTSD. Methylomic profiles derived from peripheral blood are well-suited for investigating PTSD because DNA methylation (DNAm) encodes individual response to trauma and may play a key role in the immune dysregulation characteristic of PTSD pathophysiology. In the current study, we leveraged recent methodological advances to investigate sex-specific differences in DNAm-based leukocyte composition that are associated with lifetime PTSD. We estimated leukocyte composition on a combined methylation array dataset (483 participants, ∼450 k CpG sites) consisting of two civilian cohorts, the Detroit Neighborhood Health Study and Grady Trauma Project. Sex-stratified Mann-Whitney U test and two-way ANCOVA revealed that lifetime PTSD was associated with significantly higher monocyte proportions in males, but not in females (Holm-adjusted p-val < 0.05). No difference in monocyte proportions was observed between current and remitted PTSD cases in males, suggesting that this sex-specific difference may reflect a long-standing trait of lifetime history of PTSD, rather than current state of PTSD. Associations with lifetime PTSD or PTSD status were not observed in any other leukocyte subtype and our finding in monocytes was confirmed using cell estimates based on a different deconvolution algorithm, suggesting that our sex-specific findings are robust across cell estimation approaches. Overall, our main finding of elevated monocyte proportions in males, but not in females with lifetime history of PTSD provides evidence for a sex-specific difference in peripheral blood leukocyte composition that is detectable in methylomic profiles and that may reflect long-standing changes associated with PTSD diagnosis.

High-Dimensional Profiling Reveals Heterogeneity of the Th17 Subset and Its Association With Systemic Immunomodulatory Treatment in Non-infectious Uveitis.

Background: Non-infectious uveitis (NIU) is a severe intra ocular inflammation, which frequently requires prompt systemic immunosuppressive therapy (IMT) to halt the development of vision-threatening complications. IMT is considered when NIU cannot be treated with corticosteroids alone, which is unpredictable in advance. Previous studies have linked blood cell subsets to glucocorticoid sensitivity, which suggests that the composition of blood leukocytes may early identify patients that will require IMT.Objective: To map the blood leukocyte composition of NIU and identify cell subsets that stratify patients that required IMT during follow-up.Methods: We performed controlled flow cytometry experiments measuring a total of 37 protein markers in the blood of 30 IMT free patients with active non-infectious anterior, intermediate, and posterior uveitis, and compared these to 15 age and sex matched healthy controls. Results from manual gating were validated by automatic unsupervised gating using FlowSOM.Results: Patients with uveitis displayed lower relative frequencies of Natural Killer cells and higher relative frequencies of memory T cells, in particular the CCR6+ lineages. These results were confirmed by automatic gating by unsupervised clustering using FlowSOM. We observed considerable heterogeneity in memory T cell subsets and abundance of CXCR3-CCR6+ (Th17) cells between the uveitis subtypes. Importantly, regardless of the uveitis subtype, patients that eventually required IMT in the course of the study follow-up exhibited increased CCR6+ T cell abundance before commencing therapy.Conclusion: High-dimensional immunoprofiling in NIU patients shows that clinically distinct forms of human NIU exhibit shared as well as unique immune cell perturbations in the peripheral blood and link CCR6+ T cell abundance to systemic immunomodulatory treatment.

Estrogen serum concentration affects blood immune cell composition and polarization in human females under controlled ovarian stimulation

Estrogens modulate the immune system and possess anti-inflammatory properties. In line, immune cells express a variety of estrogen receptors (ER) including ER-alpha and -beta. In the present study, we examined the influence of 17beta-estradiol (E2) serum concentrations on blood leukocyte composition and their ex vivo polarization/activation status by FACS analysis in sub-fertile human females under controlled ovarian stimulation (COS). Using a set of cell-type and polarization-specific markers, we demonstrate that increased 17ß-estradiol (E2) serum concentrations yield an overall increase in leukocytes, neutrophils and monocytes but decreased lymphocytes. There was a clear ratio shift towards an increase in M2 monocytes with a protective quality and an increase in T-helper cells compared to a decrease in cytotoxic T-cells. These data support experimental findings and clinical trials, i.e. related to multiple sclerosis and other autoimmune-related diseases, that have shown a down-regulation of CD8(+) T cells and up-regulation of T-regulatory cells. Further studies have to pinpoint to which extent the immune system/-responsiveness of otherwise healthy female patients is affected by medium-term systemic E2 variations.

Difference in Leukocyte Composition between Women before and after Menopausal Age, and Distinct Sexual Dimorphism.

There are sex differences in many inflammatory and immune diseases, and the differences tend to diminish after menopause. The underlying reasons are unclear, but sex hormone levels are likely to be an important factor. Blood leukocyte count and composition provide an indicator of the inflammatory and immune status of an individual. We performed a cross-sectional analysis of blood leukocyte data from 46,879 individuals (26,212 men and 20,667 women, aged 18 to 93 years) who underwent a routine health checkup. In women aged around 50 years, neutrophil percentage (NE%) dropped whilst lymphocyte percentage (LY%) rose. Accordingly, women before age 50 had significantly higher NE%, lower LY%, and higher neutrophil-to-lymphocyte ratio (NLR) than women of 51–70 years of age (p = 1.35×10−82, p = 5.32×10−100, and p = 1.25×10−26, respectively). In age groups of <50 years, women had higher NE%, lower LY% and higher NLR than men (p = 1.82×10−206, p = 1.46×10−69, and p = 2.30×10−118, respectively), whereas in age groups of >51 years, it was the reverse (p = 1.92×10−15, p = 1.43×10−84, and p = 1.51×10−48, respectively). These results show that blood leukocyte composition differs between women before and after menopausal age, with distinct sexual dimorphism.

Ascites bacterial burden and immune cell profile are associated with poor clinical outcomes in the absence of overt infection.

Bacterial infections, most commonly spontaneous bacterial peritonitis in patients with ascites, occur in one third of admitted patients with cirrhosis, and account for a 4-fold increase in mortality. Bacteria are isolated from less than 40% of ascites infections by culture, necessitating empirical antibiotic treatment, but culture-independent studies suggest bacteria are commonly present, even in the absence of overt infection. Widespread detection of low levels of bacteria in ascites, in the absence of peritonitis, suggests immune impairment may contribute to higher susceptibility to infection in cirrhotic patients. However, little is known about the role of ascites leukocyte composition and function in this context. We determined ascites bacterial composition by quantitative PCR and 16S rRNA gene sequencing in 25 patients with culture-negative, non-neutrocytic ascites, and compared microbiological data with ascites and peripheral blood leukocyte composition and phenotype. Bacterial DNA was detected in ascitic fluid from 23 of 25 patients, with significant positive correlations between bacterial DNA levels and poor 6-month clinical outcomes (death, readmission). Ascites leukocyte composition was variable, but dominated by macrophages or T lymphocytes, with lower numbers of B lymphocytes and natural killer cells. Consistent with the hypothesis that impaired innate immunity contributes to susceptibility to infection, high bacterial DNA burden was associated with reduced major histocompatibility complex class II expression on ascites (but not peripheral blood) monocytes/macrophages. These data indicate an association between the presence of ascites bacterial DNA and early death and readmission in patients with decompensated cirrhosis. They further suggest that impairment of innate immunity contributes to increased bacterial translocation, risk of peritonitis, or both.

Influences of age and sex on leukocytes of healthy horses and their ex vivo cytokine release

Leukocytes and their functional capacities are used extensively as biomarkers in immunological research. Commonly employed indicators concerning leukocytes are as follows: number, composition in blood, response to discrete stimuli, cytokine release, and morphometric characteristics. In order to employ leukocytes as biomarkers for disease and therapeutic monitoring, physiological variations and influencing factors on the parameters measured have to be considered. The aim of this report was to describe the ranges of selected leukocyte parameters in a sample of healthy horses and to analyse whether age, sex, breed, and sampling time point (time of day) influence peripheral blood leukocyte composition, cell morphology and release of cytokines ex vivo. Flow cytometric comparative characterisation of cell size and complexity in 24 healthy horses revealed significant variance. Similarly, basal release of selected cytokines by blood mononuclear cells also showed high variability [TNFα (65–16,624pg/ml), IFNγ (4–80U/ml), IL-4 (0–5069pg/ml), IL-10 (49–1862pg/ml), and IL-17 (4–1244U/ml)]. Each animal's age influenced leukocyte composition, cell morphology and cytokine release (TNFα, IL-4, IL-10) ex vivo. Geldings showed smaller monocytes and higher spontaneous production of IL-10 when compared to the mares included. The stimulation to spontaneous release ratios of TNFα, IL-4 and IL-17 differed in Warmblood and Thoroughbred types. Sampling time influenced leukocyte composition and cell morphology. In summary, many animal factors – age being the dominant one – should be considered for studies involving the analysis of equine leukocytes. In addition, high inter-individual variances argue for individual baseline measurements.

Synergy of therapeutic vaccination against HPV16 oncogenic proteins and standard chemotherapeutics

We previously developed a synthetic long peptide (SLP) vaccine against HPV16 oncoproteins that induced lesion regression in patients with HPV16+ high-grade vulvar intraepithelial neoplasia, correlated with strong vaccine-prompted HPV16-specific T cell responses. In patients with HPV16-induced metastatic cervical cancer, vaccine-induced T cell responses were weaker and did not result in improved clinical outcome. In a preclinical HPV16 E6/E7+ mouse tumor model we studied the efficacy of SLP vaccination combined with chemotherapy. Mice that received either peptide vaccination or chemotherapy showed only temporary tumor regression. Importantly, combined chemo-immunotherapy induced complete tumor eradication in 75% of the mice, which was associated with a strong tumor influx of vaccine specific tumor necrosis factor alpha (TNFα) and interferon gamma (IFN-γ) producing CD8+ CTLs. Tumor cells incubated with TNFα and IFN-γ, together with cisplatin, enhanced their chemokine expression and SLP vaccine-induced CTLs appeared to migrate earlier into the tumor beds. Combination treatment in vitro caused a decrease in proliferation of tumor cells and TNFα-induced enhancement of cisplatin- mediated tumor cell death, accompanied by increased expression of pro-apoptotic molecules. SLP vaccination together with carboplatin and paclitaxel, a standard combined chemotherapy, caused marked decline in the abnormally high numbers of myeloid cells in blood and tumor in the mouse model, again associated with synergy in tumor eradication. Hence, standard chemotherapy promotes the effects of SLP vaccination by better attraction of T cells into tumors, greater sensitivity of tumors to TNFα-mediated apoptosis, and better expansion of T cells through depletion of myeloid derived suppressor cells without suppression of T cells, allowing synergy in tumor eradication. A clinical pilot study on the composition of blood leukocytes in late stage cervical cancer patients also revealed high numbers of myeloid cells, associated with low T cell responses, indicating an immunosuppressed status. When these patients were treated with carboplatin-paclitaxel chemotherapy their immune profile was normalized to that of healthy subjects. Therefore a clinical trial was performed in which late-stage cervical cancer patients were treated with standard chemotherapy in combination with HPV16 SLP vaccination. Immunomonitoring confirmed the beneficial effect of myeloid cell depletion associated with a robust induction of HPV16-specific T cell responses that were sustained throughout several cycles of chemotherapy.

Modeling immunity and inflammation in stroke: differences between rodents and humans?

A recent article “Genomic responses in mouse models poorly mimic human inflammatory diseases” showed that among genes that changed significantly in humans, the murine orthologs were close to random in matching their human counterparts.1 Although this study focused on sepsis, it also raises questions about how well the rodent inflammatory response corresponds to the human inflammatory response after ischemic stroke. In this essay we argue that the peripheral inflammatory response in rodent ischemic stroke models is different than in human stroke. Given the important role of the immune system in stroke, this could be a major handicap in translating results in rodent stroke models to clinical trials in patients with stroke. Leukocyte composition in blood differs considerably in humans compared with rodents. In humans ≈50% to ≈60% of leukocytes are neutrophils and 15% to 30% are lymphocytes. In contrast, rats and mice have only 15% to 20% neutrophils and ≈60% lymphocytes. The impact of such a difference in stroke is uncertain, although certainly noteworthy. Functional differences in the immune systems of rodents and humans also exist. For example, rodents are much more resistant to infections compared with humans after surgical …

Monocytes/macrophages and natural killer cells characterize the tumor microenvironment of inflammatory breast cancer in Egyptian patients.

Abstract Abstract #1054 Background: Inflammatory breast cancer (IBC) is the most aggressive form of breast cancer. IBC incidence appears to be higher in Egypt as compared to USA. Although the role of leukocytes in regulating breast cancer dissemination has been studied extensively, their role in IBC progression is not well understood. Previously, we showed that human monocytes augment the invasiveness and proteolytic activity of IBC cell lines. Aim: To compare the immunophenotype of IBC and non-IBC and to identify IBC tumor-infiltrated immune cell that may be associated with poor prognosis of IBC.&amp;#x2028; Methods: We enrolled two groups of patients: IBC (n=13) and non-IBC (n=27) being treated at Ain Shams University hospitals. All patients underwent modified radical mastectomy. IBC patients had 7 or more metastatic axillary lymph nodes whereas non-IBC patients had 3 or less metastatic axillary lymph nodes. During surgery, blood draining from the breast tumor microenvironment, through branches of axillary vein, and peripheral blood was collected. Total mononuclear cells were isolated from collected blood and their phenotype was examined using flow cytometry. Monoclonal antibodies specific for cell surface markers for particular cells types were used: namely T-helper cells (CD3+CD4+), T-cytotoxic cells (CD3+CD4-), natural killer (NK) cells (CD56+) and monocytes/macrophages (CD14+). Results: Within each group we compared the leukocytic composition of blood collected from the tumor drainage to that of peripheral blood in IBC and non-IBC patients. 1) In IBC, we detected a significant increase in the mean percentage of NK cells and monocytes collected from the tumor site, but no significant difference in CD8+ and CD4+ cells. 2) In non-IBC, the percentage of CD4+ T cells collected from the tumor site was significantly higher than from peripheral blood. No significant differences were detected in CD8+, CD56+ and CD14+ cells.&amp;#x2028; We compared the leukocyte composition of blood collected from both IBC and non-IBC patients. 1) In peripheral blood of IBC patients, we detected a significant increase in CD4+ T cells, but no significant differences in CD8+, CD56+ and CD14+ cells when compared to non-IBC patients. 2) When we compared the leukocyte content of blood collected from the tumor site in IBC and non-IBC, we found a significant increase in CD56+, and CD14+ cells and a significant decrease in CD4+ T cells in IBC, but no significant difference in CD8+ T cells. Conclusion: Differences in the immunophenotype of IBC versus non-IBC suggests a role for these immune cells in the metastatic dissemination and progression of IBC. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 1054.

Ultraviolet B Irradiation Modulates the Immune System of Fish (Rutilus rutilus, Cyprinidae) II: Blood

The effects of a single dose of ultraviolet B (UVB) radiation (0.4 J/cm2) on immunological functions by blood leukocytes and on hematological parameters was studied in roach (Rutilus rutilus), a teleostean fish. The respiratory burst of phorbol 12-myristate 13-acetate stimulated whole blood phagocytes increased significantly after UVB irradiation but spontaneous cytotoxicity of blood leukocytes toward 51chromium-labeled K562 target cells was not markedly altered. Differential cell counting revealed that UVB exposure significantly increased the proportion of granulocytes and significantly decreased the proportion of lymphocytes in the peripheral blood, whereas hematocrit and the total number of white and red blood cells were unchanged. Plasma cortisol concentration increased in UVB-exposed fish. Severe handling stress caused similar, although not as potent, effects on the measured parameters of fish blood as UVB irradiation. These observations suggest that in fish UVB brings about a stress response, which may account for the observed alterations in the immune parameters and leukocyte composition of blood. Exposure of fish to strong visible light induced no alterations in immunological or hematological parameters, making it unlikely that ultraviolet radiation mediates its effects through visual perception.

A reduced peripheral blood CD4 + lymphocyte proportion is a consistent ageing phenotype

Peripheral blood leukocyte composition was measured in young, middle-aged and old C57BL/6J (B6) and BALB/cByJ (BALB) mice by flow cytometry to test the hypothesis that ageing is associated with declines in the proportions of peripheral blood T lymphocytes. In both B6 and BALB mice, increasing age is associated with a significant and continuous decline in the proportions of CD4 + lymphocytes, a moderate decline in the proportion of CD8 + lymphocytes, a significant increase in the proportion of Gr1 + granulocytes and an almost unchanged proportion of B lymphocytes. As expected, the proportion of CD44 low naive T lymphocytes decreased with age. Expression of Fas (CD95 +) on CD4 + and CD8 + lymphocytes showed no consistent change with age. We also measured peripheral blood CD4 + and CD8 + lymphocyte proportions in young and old A/J, CBA/CaJ, DBA/2J, DW/J and (DW×C3H) F1 mice. The CD4 + lymphocyte proportion decreased from young to old age in these strains by 56, 65, 72, 78 and 68%, respectively. The CD8 + lymphocyte proportion decreased moderately with age in all the inbred strains tested but not in the (DW×C3H) F1 hybrid. Thus, a reduced proportion of peripheral blood CD4 + lymphocytes is a consistent ageing phenotype in a wide range of Mus musculus strains.

Ultraviolet B irradiation modulates the immune system of fish (Rutilus rutilus, Cyprinidae). II: Blood.

The effects of a single dose of ultraviolet B (UVB) radiation (0.4 J/cm2) on immunological functions by blood leukocytes and on hematological parameters was studied in roach (Rutilus rutilus), a teleostean fish. The respiratory burst of phorbol 12-myristate 13-acetate stimulated whole blood phagocytes increased significantly after UVB irradiation but spontaneous cytotoxicity of blood leukocytes toward 51chromium-labeled K562 target cells was not markedly altered. Differential cell counting revealed that UVB exposure significantly increased the proportion of granulocytes and significantly decreased the proportion of lymphocytes in the peripheral blood, whereas hematocrit and the total number of white and red blood cells were unchanged. Plasma cortisol concentration increased in UVB-exposed fish. Severe handling stress caused similar, although not as potent, effects on the measured parameters of fish blood as UVB irradiation. These observations suggest that in fish UVB brings about a stress response, which may account for the observed alterations in the immune parameters and leukocyte composition of blood. Exposure of fish to strong visible light induced no alterations in immunological or hematological parameters, making it unlikely that ultraviolet radiation mediates its effects through visual perception.

Responses of leukocytes and other hematologic parameters to thermal dehydration.

Effects of thermal dehydration without exercise on leukocyte differentials, serum protein fractions, and other hematologic characteristics were studied in six healthy subjects. Both leukocyte and serum total protein levels increased beyond that predicted by hemoconcentration alone. Eosinophil counts decreased significantly, although other leukocyte counts tended to increase. Serum globulin concentrations tended to increase, but the albumin level did not change. Serum K+ concentration was elevated, but Na+ and Cl- were unaffected. It is suggested that thermal dehydration affects blood leukocyte composition and protein metabolism in many of the same ways as physical exercise.