Abnormal development of secondary lymphoid tissues in lymphotoxin beta-deficient mice

The tumor necrosis factor (TNF) family cytokines lymphotoxin (LT) alpha and LTbeta form heterotrimers that are expressed on the surface of activated lymphocytes and natural killer cells; LTalpha homotrimers can be secreted as well. Mice with a disrupted LTalpha gene lack lymph nodes (LN), Peyer's patches (PP), and follicular dendritic cell (FDC) networks and reveal profound defects of the splenic architecture. However, it is unclear which of these abnormalities is the result of the absence in LTalpha homotrimers or LTalphabeta heterotrimers. To distinguish between these two possibilities, a mouse strain deficient in LTbeta was created employing Cre/loxP-mediated gene targeting. Mice deficient in LTbeta reveal severe defects in organogenesis of the lymphoid system similar to those of LTalpha-/- mice, except that mesenteric and cervical LN are present in most LTbeta-deficient mice. Both LTbeta- and LTalpha-deficient mice show significant lymphocytosis in the circulation and peritoneal cavity and lymphocytic infiltrations in lungs and liver. After immunization, PNA-positive B cell clusters were detected in the splenic white pulp of LTbeta-deficient mice, but FDC networks were severely underdeveloped. Collectively, these results indicate that LTalpha can signal independently from LTbeta in the formation of PNA-positive foci in the spleen, and especially in the development of mesenteric and cervical LN.     

Catecholamine modulation of lymphocyte homing to lymphoid tissues

Lymphocyte migration is an essential process for immune surveillance and for promoting cell-cell interactions necessary to generate an immune response. This report examined whether catecholamine prestimulation would alter the pattern of lymphocyte homing to spleen and lymph nodes in mice as determined by tracking fluorescently labeled cells. The results of cell sorter analysis showed that catecholamine-pretreated cells had increased accumulation in spleen and lymph nodes 1 and 2 h after i.v. injection. In addition, microscopic analysis showed that labeled cells migrated from the splenic red pulp to T-cell regions of the white pulp over a 2-h time course. Within the lymph nodes, labeled cells localized predominantly to the pericortex. Additional studies examined the migration of lymphocytes to lymphoid tissues of NGF-transgenic mice that have sympathetic hyperinnervation of spleen and peripheral lymph nodes. In contrast to the studies above, migration of T-cells from control mice to lymphoid tissues of the hyperinnervated mice was not different than that in control mice in most tissues. The accumulation of lymphocytes in lymphoid tissues is a balance between the influx of newly migrated cells and efflux back into the circulation. The studies in this report lend support to other studies showing catecholamine modulation of lymphocyte migration and homing, but it is a complex process about which much has yet to be understood.     

T cell engraftment in lymphoid tissues of human peripheral blood lymphocyte reconstituted SCID mice with or without prior activation of cells

A controlled study was undertaken to determine the stability of LSD in pooled urine samples. The concentrations of LSD in urine samples were followed over time at various temperatures, in different types of storage containers, at various exposures to different wavelengths of light, and at varying pH values. LSD concentrations were measured quantitatively by the Abuscreen RIA and by HPLC using a fluorescence detection method. Good correlation was observed between the immunoassay and the fluorescent integrity of the LSD molecule. Thermostability studies were conducted in the dark with various containers. These studies demonstrated no significant loss in LSD concentration at 25 degrees C for up to 4 weeks. After 4 weeks of incubation, a 30% loss in LSD concentration at 37 degrees C and up to a 40% at 45 degrees C were observed. Urine fortified with LSD and stored in amber glass or nontransparent polyethylene containers showed no change in concentration under any light conditions. Stability of LSD in transparent containers under light was dependent on the distance between the light source and the samples, the wavelength of light, exposure time, and the intensity of light. After prolonged exposure to heat in alkaline pH conditions, 10 to 15% of the parent LSD epimerized to iso-LSD. Under acidic conditions, less than 5% of the LSD was converted to iso-LSD. We also demonstrated that trace amounts of metal ions in buffer or urine could catalyze the decomposition of LSD and that this process can be avoided by the addition of EDTA. This study demonstrates the importance of proper storage conditions of LSD in urine in order to insure proper analytical testing results over time.     

Experimental mucosal disease in cattle: changes of lymphocyte subpopulations in Peyer's patches and in lymphoid nodules of large intestine

Changes in the number and distribution of lymphocyte subtypes were investigated in Peyer's patches in the jejunum and ileum, and mucosa-associated lymphoid nodules in the proximal colon and rectum of cattle with end-stage mucosal disease. Mucosal disease had been induced experimentally in seven of 13 animals by inoculation with cytopathogenic bovine viral diarrhea virus (cp BVD-virus). For comparison, six clinically healthy, persistently viremic cattle were used. IgM+, IgA+, BoCD4+, BoCD8+ and gamma delta TCR+lymphocytes, and the cp BVD-viral antigen were visualized in tissue sections by immunohistochemistry. In cattle with mucosal disease, the size of lymphoid follicles was significantly decreased in all localizations resulting in decreased numbers of B-lymphocytes per average follicular area. In most animals domes were missing and epithelium was invaginated into the lymphoid follicles. Numbers of BoCD4+ and BoCD8 + T-lymphocytes were increased per mm2 of lymphoid follicle. Conversion of these counts into number of cells per average follicular area revealed, however, that the absolute number of BoCD4 + T-lymphocytes had decreased within lymphoid follicles and there was no distinct change of BoCD8 + T-lymphocytes in comparison to the controls. Interfollicular areas were less densely populated due to reduced numbers of BoCD4 + and BoCD8 + T-lymphocytes. cp BVD-viral antigen was detected predominantly in epithelial cells and in cells with dendritic morphology within lymphoid follicles. This may indicate that the severe depletion of B-lymphocytes in the lymphoid follicles is due to alterations of the microenvironment. The decrease of BoCD4 + and BoCD8 + T-lymphocytes does not support the hypothesis of T-cell-mediated tissue damage. Destruction of mucosa-associated lymphoid nodules does not only lead to local disruption of the gastrointestinal barrier, but will reduce the seeding of effector cells to the mucosa and therefore impair the defense mechanisms of the gastrointestinal barrier.     

Localization of corticotropin-releasing factor in primary and secondary lymphoid organs of the rat

Cells of the immune system produce a variety of neuropeptides or peptide hormones, either constitutively or upon induction, and possess specific neuropeptide receptors that display ligand-receptor interactions similar to those described in the central nervous system (CNS). These findings suggest that specific subsets of lymphoid cells can produce and respond to peptides previously thought to be principally neural mediators. Recently, corticotropin releasing factor (CRF) mRNA was detected in the rat thymus and spleen, although the cells that synthesize CRF were not identified. We examined the localization of CRF and its mRNA in the rat spleen, thymus, and mesenteric lymph nodes using immunocytochemistry (ICC) and in situ hybridization (ISH), respectively. Immunoreactive CRF was present in cells in the marginal zone and red pulp of the spleen, in connective tissue septa and the subcapsular region of the thymus, and in the medullary cords and sinuses of the mesenteric lymph nodes. Dual ICC/ISH for CRF and its mRNA, respectively, demonstrated CRF mRNA over CRF-immunoreactive cells, suggesting CRF synthesis. Double-label ICC for CRF and markers for specific immunocyte subsets suggest that CRF+ cells in the spleen and thymus are macrophages. CRF+ cells in primary and secondary lymphoid organs reside in compartments that are innervated by sympathetic nerves, and some cells appears to be contacted by noradrenergic sympathetic nerve fibers, suggesting that CRF release may be influenced by the sympathetic nervous system, as it is in the hypothalamo-pituitary-adrenal axis. The presence of CRF in organs of the immune system suggests that this neuropeptide may modulate immune functions after paracrine release.     

Prenatal ontogeny of lymphocyte subpopulations in pigs

Although porcine lymphocytes have been classified into numerous subpopulations in postnatal animals, little is known about the ontogeny of these complex cell subsets. Using double- and triple-colour flow cytometry (FCM), we investigated the surface phenotype of fetal lymphoid cells in the thymus, cord blood, spleen and mesenteric lymph nodes at different stages of gestation. It was found that the major lymphocyte subpopulations started to appear at the beginning of the second third of the gestation period, with B cells being the earliest lymphocyte subpopulation to appear in the periphery. The T-cell receptor (TCR) gamma delta+ cells were the earliest detectable T-cell subset, developing first in the thymus and subsequently arriving in the periphery. Later in ontogeny, however, the number of TCRalpha beta+ lymphocytes rapidly increased, becoming the predominant T cells both in the thymus and in the periphery. Cells with the phenotype of adult natural killer cells were also identified in pig fetuses, though their nature and functional roles remain to be investigated. In addition, CD2 was expressed on most B cells whilst very few CD4+ TCRalpha beta+ cells or CD2+ TCRgamma delta+ cells expressed CD8, suggesting that the expression of CD2 and CD8 may reflect the functional status of the cells in postnatal animals. Taken together, this study has provided a systematic analysis of fetal porcine lymphocyte subpopulations and may provide the base for studies to establish the physiological roles of these lymphocyte subsets.     

Mice lacking expression of secondary lymphoid organ chemokine have defects in lymphocyte homing and dendritic cell localization

Secondary lymphoid organ chemokine (SLC) is expressed in high endothelial venules and in T cell zones of spleen and lymph nodes (LNs) and strongly attracts naive T cells. In mice homozygous for the paucity of lymph node T cell (plt) mutation, naive T cells fail to home to LNs or the lymphoid regions of spleen. Here we demonstrate that expression of SLC is undetectable in plt mice. In addition to the defect in T cell homing, we demonstrate that dendritic cells (DCs) fail to accumulate in spleen and LN T cell zones of plt mice. DC migration to LNs after contact sensitization is also substantially reduced. The physiologic significance of these abnormalities in plt mice is indicated by a markedly increased sensitivity to infection with murine hepatitis virus. The plt mutation maps to the SLC locus; however, the sequence of SLC introns and exons in plt mice is normal. These findings suggest that the abnormalities in plt mice are due to a genetic defect in the expression of SLC and that SLC mediates the entry of naive T cells and antigen-stimulated DCs into the T cell zones of secondary lymphoid organs.     

Social-hygienic study of the epidemiology of primary and secondary female infertility

Incidence of primary and secondary female infertility is analyzed from results of 10-year follow-up of 3478 couples married in Ryazan, a city in Central Russia. Data of sociohygienic studies of epidemiology of sterility should be taken into consideration when planning measures aimed at prevention of reproductive disorders in various sociodemographic strata of population.     

IL-2 receptor alpha-chain expression is independently regulated in primary and secondary lymphoid organs

The IL-2R is composed of three chains: IL-2R alpha, IL-2R beta, and IL-2R gamma. In mice, IL-2Ra is critical and determines IL-2 binding to the tripartite IL-2R complex. To extend our previous studies, which demonstrated that IL-2 regulates IL-2R alpha expression in vitro, we have analyzed expression in IL-2-deficient mice in vivo. As in control animals, CD4- CD8- thymocytes and bone marrow-derived B220+ pre-B cells were IL-2R alpha positive. In contrast, activated lymph node and splenic CD4 T cells (CD4+ CD69+) were found to be IL-2R alpha negative, whereas approximately 20% of the same cell populations from the MLR/lpr strain, which also accumulate large numbers of CD4-activated T cells in the presence of intact IL-2, retained expression. A similar pattern of IL-2R alpha expression was found among splenic CD8 cells from IL-2(-/-) and IL-2(+/-) animals. These findings demonstrate that in primary lymphoid organs, IL-2 is not directly involved in IL-2R alpha expression. However, at the level of mature lymphocytes, and more specifically CD4 T cells, IL-2 remains in vivo, as in vitro, the most critical cytokine controlling both IL-2R alpha expression and sensitivity to IL-2.     

Studies on lymphocyte subpopulations and the effect of age on immune competence in turkeys

We characterized the lymphocyte subpopulations and investigated the effect of age on cellular and humoral immunity, development of lymphoid organs, and the relative proportions of CD4+ and CD8+ cells in turkeys. The mitogenic responses of peripheral T cells were poorly developed at hatch but developed rapidly after hatch and reached adult levels by 2 weeks-of-age. The average percentage of CD4+ cells was 45, 29.8, and 26.3 in the thymi, peripheral blood, and spleens, respectively, in turkeys. The mean percentage of CD8+ cells in the thymi, peripheral blood, and spleens of turkeys was 53.8, 13.6, and 15.5, respectively. Age did not influence the relative proportions of CD4+ and CD8+ T cells in the spleens and peripheral blood of turkeys. The mean percentages of IgM+ cells in the bursae and spleens were 78.5 and 26.8, respectively. Day-old turkeys did not develop detectable antibodies to either thymus dependent or independent antigens. However, 2 week or older turkeys showed good humoral responses. Inoculation of BSA at hatch induced tolerance, whereas injection of SRBC did not. Analysis of relative organ weights of turkey lymphoid organs showed that spleens and thymi developed rapidly during the first week-of-age.     

Effects of a muscarinic antagonist on various components of female sexual behavior in the rat.

Effects of the muscarinic antagonist scopolamine on lordosis, solicitation, pacing, approach, attractivity, and activity were evaluated in ovariectomized rats brought into sexual receptivity with estrogen and progesterone. Systemic (1 mg/rat) or intraventricular (10 μg bilaterally) administration of scopolamine significantly reduced the incidence of lordosis and solicitation behaviors and disrupted typical pacing of sexual contacts with a stimulus male. In addition, females avoided contact with a stimulus male, but not a stimulus female, following intraventricular infusion of scopolamine. The levels of general activity and frequencies of sexual contacts were similar in females treated intraventricularly with scopolamine and vehicle solutions. Consequently, scopolamine disrupted various components of sexual behavior, including lordosis, solicitation, pacing, and approach, without altering female attractivity or general activity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modulation of in vitro lymphocyte stimulation by subpopulations of transforming lymphocytes

The finding of less-than-expected lymphocyte transformation by both PHA-P and PWM acting together supports the possibility that subpopulations of lymphocytes may interact to suppress their transformation and thereby help regulate the immune response.     

Analysis of splenic and thymic lymphocyte subpopulations in chickens infected with Salmonella enteritidis

Lymphocytes expressing CD3, CD4, CD8, pan lymphocyte, IgA, IgG and IgM cell surface antigens were assessed by in the spleen and thymus of chickens following infection with Salmonella enteritidis using flow cytometric analysis. At 6 days post primary infection and 2 days post secondary infection with S. enteritidis, the percentages of IgA+ and IgM+ lymphocytes in the spleen were significantly increased (P < 0.05). At 2 days post secondary infection with S. enteritidis, the percentage of CD4+ T lymphocyte in the spleen and CD8+ T lymphocyte percentage in the thymus were significantly increased (P < 0.05). These results indicate that S. enteritidis infection induces changes in the spleen and thymus that reflect the dynamics of the host protective immune response.     

Natural killing and antibody-dependent cytotoxicity by lymphocyte subpopulations in young and aging humans

Natural killer (NK) and antibody-dependent cellular cytotoxicity (ADCC) were examined in the peripheral blood lymphocytes and their major subpopulations from young and aging subjects. Monocyte-depleted unseparated lymphocyte-mediated NK activity (against cells of K-562) and ADCC (against IgG-coated chicken erythrocytes) were comparable between young and aging subjects. Similarly no significant difference was observed in T cell-mediated NK and ADCC and non-T cell-mediated ADCC between young and aging subjects. Non-T cell-mediated NK activity, however, was significantly (P less than 0.025) greater in aging humans compared to that of young subjects. When the data were analyzed according to gender, T cell-mediated ADCC in aging males was significantly (P less than 0.05) greater than that found in young males. No significant difference was observed between T-cell ADCC among young and aging females. T cell-mediated NK was comparable among young and aging males and young and aging females. Non-T cell-mediated NK as well as ADCC activity was significantly (P[ less than 0.025 or less than 0.05) greater in aging males compared to that in young males. Both non-T-cell NK and ADCC were comparable among young and aging females. This study demonstrates an increase in NK and ADCC activity in aging subjects that is primarily shared by males and not by females. No correlation was observed between the proportion of T gamma cells and T-cell NK or ADCC activity.     

Effects of dietary retinoic acid on skin papilloma and carcinoma formation in female SENCAR mice

Previously we have shown that dietary retinoids are essential for papilloma formation induced by either an initiation-promotion or a complete skin carcinogenesis protocol. The present study was conducted to further determine the effect of dietary retinoic acid (RA) on papilloma formation and the conversion of papillomas to carcinomas. Skin tumors were induced in 3 week old female SENCAR mice by an initiation-promotion protocol with one application of 20 micrograms of 7,12-dimethylbenz[a]anthracene (DMBA), followed by 20 weekly applications of 2 micrograms of 12-O-tetradecanoylphorbol-13-acetate (TPA). Mice were fed RA at one of the three doses: 0.3 (nutritionally marginal dose), 3 (near physiological) and 30 (pharmacological) micrograms/g of diet. Mice fed 30 micrograms of RA/g of diet had the same survival rate as the other two groups despite a lower body weight and all three groups had similar papilloma incidence, which reached 100% at age 18 weeks. Mice fed 3 micrograms of RA/g of diet had the highest papilloma yield (approximately 14 papillomas/mouse) of all groups and it peaked between weeks 18 and 38 of age. These papillomas later regressed such that mice from all three groups had about the same papilloma yield at week 44 of age. Mice fed 30 micrograms of RA/g of diet failed to develop any visible carcinoma, while mice fed 0.3 or 3 micrograms/g showed 1.9% conversion of papillomas to carcinomas. Therefore, dietary RA at 30 micrograms/g of diet inhibited the conversion of papillomas to carcinomas without affecting papilloma incidence. In addition, dietary RA at 30 and 0.3 micrograms/g of diet lowered papilloma yield.     

Vinorelbine: cell cycle kinetics and differential sensitivity of human lymphocyte subpopulations

Antiproliferative activity induced by vinorelbine (VRB) was studied in whole blood cultures (WBC) and in lymphocyte subpopulations evaluated by the MAC (morphology-antibody-chromosome) method. In WBC a significant delay in cell cycle kinetics in VRB-treated cultures compared with controls (P < 0.001) was observed. The highest dose (1.0 microg/ml) arrested all cells at the first metaphase. Both WBC and isolated lymphocyte cultures showed a significant increase in the mitotic index (MI) in VRB-treated cultures compared with controls (P < 0.001). Moreover, a significant increase in the MI was found in VRB-treated CD4 cells compared with VRB-treated CD8 (P < 0.01) and B-lymphocytes (P < 0.001).     

Lymphocyte phenotyping in infants: maturation of lymphocyte subpopulations and the effects of HIV infection

Oxygen administration is one of the most important therapeutic interventions for a child with severe acute lower respiratory tract infection (ALRI). Inexpensive and efficient methods of oxygen administration are highly desirable in hospitals in developing countries. The objectives of this study were to compare the frequency and nature of complications when nasopharyngeal catheters or nasal prongs are used to deliver oxygen. One hundred and twenty-one children between the ages of 2 weeks and 5 years with hypoxia due to ALRI were randomized to receive oxygen via a catheter (61 children) or via nasal prongs (60 children). The two groups were similar in terms of diagnoses, clinical severity, oxygen saturation on admission and case fatality rates. There was no difference in the incidence of hypoxaemic episodes between the two groups. The oxygen flow rates required on the day of admission for adequate oxygenation (SaO2 > 90%) ranged from 0.8 litres per minute to 1.2 litres per minute. The required oxygen flow rate decreased during the course of treatment. Mucus production was more of a problem in the catheter group, and nasal blockage, intolerance of the method of oxygen administration and nursing effort were generally higher amongst the catheter group, but none of these differences was significant. Ulceration or bleeding of the nose was significantly more common in the catheter group (19.7% vs 6.7%, p < 0.05). Abdominal distension and nasal perforation were not seen in either group. This study suggests that nasal prongs are safer, more comfortable and require less nursing expertise than nasopharyngeal catheters for administration of oxygen to children.