T-lymphocyte subpopulations and function during murine cytomegalovirus infection

To study the effects of cytomegalovirus infection on T-lymphocyte subpopulations, we determined helper (Lyt 1.2) and suppressor (Lyt 2.2) T-lymphocyte subset numbers using monoclonal antibodies and measured lymphocyte responsiveness to mitogen during sublethal murine cytomegalovirus (MCMV) infection of 3-wk-old Balb/c mice. MCMV-infected mice had reduced Lyt 1.2 to Lyt 2.2 T-lymphocyte ratios on days 1, 3, 5, and 9 of infection. Alterations in T-lymphocyte subsets were accompanied by diminished lymphocyte response to concanavalin A. Lymphocyte responsiveness and Lyt 1.2 to Lyt 2.2 ratios were maximally reduced on day 5 of MCMV infection and correlated strongly with peak virus recovery from spleen, bone marrow, and peripheral blood leukocytes. These results indicate that acute MCMV infection of mice causes abnormalities in T-lymphocyte subset ratios and responsiveness to mitogen similar to the abnormalities observed in human cytomegalovirus infections. MCMV infection of mice is a useful model to study the mechanism by which cytomegalovirus infections induce altered T-lymphocyte subpopulations.     

Lymphocyte subpopulations in anaphylactoid purpura.

The immunoglobulins, complement components C3 and C4, lymphocyte subpopulations, and K-cell activity were studied in 13 children with anaphylactoid purpura and in 12 children of the same ages who acted as controls. The children with anaphylactoid purpura had significantly lower T-cell counts, greater K-cell activity and IgM values, and lower C3 levels than the controls.     

Lymphocyte subpopulations in full-term septic neonates

PURPOSE: To estimate the absolute leukocyte and lymphocyte counts and relative and absolute sizes of CD19+ B lymphocytes, CD3+, CD4+, CD8+ and CD3+/HLA-DR+ T lymphocytes in full-term septic neonates and the influence of some perinatal risk factors on these lymphocyte subsets. METHODS: Twenty-one septic and mechanically ventilated full-term neonates (13 boys and eight girls) and 15 healthy full-term neonates born vaginally with an Apgar score > 9 and without hyperbilirubinemia were investigated. Two-color flow cytometric immunophenotyping with appropriate antibody panels using lysed whole vein blood was performed. RESULTS: The mean relative and absolute sizes of CD19+ B lymphocytes, CD3+/CD8+ and CD3+/HLA-DR+ T lymphocytes in septic neonates did not differ significantly from control. In contrast, the mean relative sizes of CD3+ and CD3+/CD4+ T lymphocytes and the CD4+/CD8+ ratio in septic neonates were significantly higher than in healthy neonates. With regard to the absolute size in septic neonates, only CD4+ T cells were significantly higher compared with the control group. Perinatal risk factors (birth asphyxia, gestation and delivery complications) had no significant effect on the relative and absolute counts of all estimated lymphocyte subpopulations in septic neonates. CONCLUSIONS: Increases in the relative sizes of CD3+ and CD3+/CD4+ T lymphocytes and the CD4+/CD8+ ratio in full-term septic neonates provides important information about changes in cell-mediated immunity during the early neonatal period.     

Lymphocyte subpopulations in primary immunodeficiency disorders.

Venous blood mononuclear cells from 42 children with primary immunodeficiency disorders and from controls matched for age were studied for lymphocyte subpopulations by E rosetting, surface immunoglobulin, and a panel of anti T cell monoclonal antibodies (OKT series). In 3 cases of severe combined immunodeficiency (SCID) due to adenosine deaminase deficiency, very few circulating T or B cells were found. The other 7 cases of SCID all had normal or, in 3 cases, very high numbers of circulating B cells, but in 6 of these very few cells showed T cell markers. One child had very high numbers of B cells and T cells with an immature pattern of reactivity similar to that found on common thymocytes. In T cell deficient children no consistent pattern was found, but in those with cartilage hair hypoplasia with immunodeficiency there was a low helper (OKT4) to suppressor (OKT8) ratio and high numbers of circulating OKT10 positive cells. In cases of X-linked agammaglobulinaemia circulating B cells were not found but the pattern of T cell markers was normal. In cases of common variable hypogammaglobulinaemia there was a wide scatter of helper (OKT4) to suppressor (OKT8) cell ratios. Five children were studied before and after treatment with the synthetic thymic hormone preparation TP5. There were appreciable alterations in the pattern of staining with anti T cell monoclonal antibodies in 4 of these cases, but in 1 case only was this accompanied by improvements in clinical and immune function.     

Familial dysequilibrium-diplegia with T-lymphocyte deficiency.

A second family is described with a combination of defective thymus-dependent immunity and cerebral palsy. The cerebral palsy comprised nonprogressive dysequilibrium and mild spastic diplegia without limb ataxia. This genetic entity of presumed autosomal recessive inheritance is clearly distinguished from ataxia-telangiectasia. Immunological abnormalities should be sought in other familial or unexplained cerebral palsy syndromes.     

T-lymphocyte subsets, thymic size and breastfeeding in infancy

We followed the changes in concentration of T-lymphocyte subsets (CD4+ and CD8+ cells) in peripheral blood and thymus size during infancy. Previous studies have found increased thymus size in breastfed infants. The present study analyzed the association between breastfeeding and the number of CD4+ and CD8+ cells. Two different populations of infants between birth and 1 year of age were examined. Study Group I: infants with a variable duration of breastfeeding. Study Group II: long-term breastfed infants. In both groups a correlation was found between CD8+ cells and the thymic index at 10 months of age. In Group I, infants still breastfed at the 8-month examination had a higher CD8% than formula-fed infants (p = 0.05), and infants breastfed at the 4-month examination had a higher CD4% at 10 months of age (p= 0.03). Group II showed an increase in the absolute number of CD4+ and CD8+ cells from 8 to 10 months of age; and a positive correlation between the number of breastfeedings per day at 8 months of age, and an increase in CD4+ cells from 8 to 10 months of age (p <0.01). In conclusion, a correlation was found between thymus size and CD8+ cells. Breastfeeding might have both a current and long-term immune-modulating effect on the developing cellular immune system.     

Analysis of proliferating lymphocyte subpopulations in newborns and adults

Surface markers of peripheral lymphocyte subpopulations were determined before and after in vitro stimulation of neonatal and adult mononuclear cells with phytohaemagglutinin (PHA) and pokeweed mitogen (PWM). The type of cell responding to each mitogen was identified by a method combining autoradiography and the peroxidase-antiperoxidase (PAP) staining method. In comparison with adults, there is a lower proportion of OKT3-positive lymphocytes in neonates (43% vs. 72%). Analysis of lymphocyte subpopulations after stimulating mononuclear cells with PHA and PWM showed that in neonates nearly the same percentages of OKT4-and OKT8-positive proliferating cells (43% and 40%, respectively) could be observed, whereas in the proliferating cells from the adults, the OKT8 surface marker predominated (41% vs. 18%).Abbreviations PHA phytohaemagglutinin - PWM pokeweed mitogen - PAP peroxidase-antiperoxidase - MEM minimal essential medium - FCS fetal calf serum - MIF migration inhibition factor - LIF leukocyte migration inhibition factor - ConA concanavalin A     

儿童传染性单核细胞增多症T细胞亚群变化

目的 探讨传染性单核细胞增多症(infectious mononucleosis,IM)患儿T细胞亚群的变化.方法 选取2005年1月至2010年12月在我院住院确诊为Epstein-Barr( EB)病毒感染引起的IM患儿60例为IM组,同期来我院门诊健康体检患儿36例为对照组.所有患儿行血常规、血涂片、T细胞亚群、肝肾功能及病毒抗体、肝炎病毒抗体检测.T细胞亚群检测包括CD3、CD4、CD8、CD4/CD8.结果 与对照组比较,IM组患儿CD3( 81.55％±9.04％)、CD8 (58.13％±13.35％)比例较对照组(53.58％±5.97％)、(31.22％±8.72％)明显升高(P＜0.05);CD4( 18.19％±7.61％)、CD4/CD8(0.37±0.33)比值较对照组(36.98％±5.32％、1.98±0.41)明显降低(P＜0.05).IM组患儿白细胞计数、异型淋巴细胞比值及谷丙转氨酶与CD4/CD8的下降无相关性(P均＞0.05).结论 EB病毒感染引起IM患儿免疫功能显著低下,可早期进行免疫干预治疗.     

Prevalence of T-lymphocyte abnormalities in infants with congenital heart disease

Thirty-two infants younger than 6 months with catheterization-proved congenital heart disease were prospectively examined for T-lymphocyte immunodeficiency (compared with adult and normal newborn controls). Cardiac lesions were separated into two groups: (1) "high-risk" lesions previously associated with T-cell abnormalities in DiGeorge's syndrome, and (2) the remaining "low-risk" lesions. Cardiac patients as a whole did not have significant abnormalities in T-cell rosette (TCR) percentages (mean +/- SE, 50.0% +/- 22%) or response to phytohemagglutinin (PHA) (72,243 +/- 38,388 counts per minute). However, a greater percentage of patients with high-risk cardiac lesions had abnormal TCR and PHA results than either the control or low-risk group, due to the inclusion of three infants with DiGeorge's syndrome. These findings suggest that newborn infants without evidence of DiGeorge's syndrome have normal T-lymphocyte function. Infants with high-risk cardiac lesions deserve a careful immunologic evaluation to avoid significant morbidity and mortality.     

Characterization of nonmotile neutrophil subpopulations in neonates and adults

Previous studies have demonstrated that polymorphonuclear leukocytes (PMN) are not a homogeneous population of cells but differ significantly in their structure and function. PMN move at varying rates, and a fraction estimated from 20 to 70% do not move at all in response to chemotactic stimuli. To characterize this PMN subpopulation better, we studied PMN motility in neonates and adults using a polycarbonate micropore filter chemotactic assay and the 31D8 MAb. Most PMN strongly bind 31D8 MAb (31D8 "bright"), but a minority (31D8 "dull") weakly bind the antibody and in this respect are similar to immature PMN precursors. The 31D8 "dull" PMN have impaired function compared with 31D8 "bright" PMN. In the present study, a PMN subpopulation that failed to migrate using the micropore filter assay accounted for 58 +/- 7% of adult PMN and was similar to the migrating subpopulation in regard to viability and phagocytic function. The nonmotile subpopulation had a higher percentage of bands (5 +/- 3% versus 1 +/- 2%, p less than 0.01) and decreased binding of 31D8 MAb compared with the motile subpopulation. Neonates had a larger nonmigrating PMN subpopulation and 31D8 "dull" PMN subpopulation than those of adults (76 +/- 3% versus 58 +/- 7%, p = 0.04 and 26 +/- 11% versus 8 +/- 2%, p less than 0.01, respectively). These data indicate that although PMN appear morphologically as a homogeneous population of cells, there exists a viable, nonmotile PMN subpopulation that may be less mature than the motile PMN subpopulation. They also indicate that impaired neonatal PMN motility may be attributable in part to an increased size of the nonmotile PMN subpopulation.     

Lymphocyte subpopulations in children with vitamin D deficient rickets

Recent studies have shown 1,25(OH)₂D₃-mediated modulation of the immune system. We examined lymphocyte subpopulations of 16 children with nutritional rickets. Most of the patients suffered more frequent infection episodes than the control group of 15 healthy children and low serum levels of 25OHD and 1,25(OH)₂D, such as 38.2 ± 8.6 ng/mL and 15.7 ± 2.6 pg/mL respectively. This decrease correlated with a significant decrease in total T lymphocytes and an increase in B lymphocytes expressing surface IgA, IgM, IgG molecules. These results suggest that vitamin D plays an important role in the impaired functions of T lymphocytes which may lead to frequent infection episodes in nutritional rickets.     

窒息早产儿T淋巴细胞亚群变化研究

目的 探讨窒息对早产儿免疫功能的影响及其临床意义.方法 采用流式细胞仪对25例轻度窒息早产儿及20例重度窒息早产儿生后第1天、第14天静脉血T淋巴细胞亚群进行测定,对照组为同期在本科住院的无窒息早产儿22例.结果 重度窒息组CD3、CD4、CD4/CD8明显低于对照组与轻度窒息组,P<0.05;轻度窒息组CD3、CD4、CD4/CD8亦明显低于对照组,P0.05),但重度窒息组各项指标与对照组比较,差异有统计学意义(P<0.05).结论 窒息缺氧可导致早产儿T淋巴细胞亚群紊乱,窒息程度越重,T淋巴细胞亚群改变越明显.