Decreased immune functions of blood cells following mobilization with granulocyte colony-stimulating factor: association with donor characteristics

In this study, mononuclear cells (MNCs) from granulocyte colony-stimulating factor (G-CSF)-mobilized blood stem cell (BSC) harvests from 104 healthy donors were analyzed for their immunological functions and compared with MNCs from 28 steady-state nonmobilized donors. The relationships between donor characteristics (age, gender, weight, and HLA type) and immune functions of the harvests were also analyzed. There was a significant (P <.01) decrease in natural killer and lymphokine-activated killer (LAK) cell-mediated cytotoxicity for G-CSF-mobilized effector cells compared with nonmobilized cells. Similarly, there was a significant (P <.005) decrease in both T-cell and B-cell mitogen response in G-CSF-mobilized cells compared with nonmobilized cells. There was dose-dependent inhibition of LAK cell-mediated cytotoxicity, but this effect was not seen with other immune function assays. Changes in immune function did not appear to be determined by frequency of cellular phenotypes or expression of effector function genes seen in a reverse-transcription polymerase chain reaction. There was a significant relationship between expression of certain HLA alleles (A1, A3, A24, B44, B62, DR15, DR17; all P <.01) and increased immune function, such as cytotoxicity and/or mitogen response. A decrease in immune function with the HLA-DR13 expression was also observed (P <.01). Since the G-CSF increases the number of MNCs, the increase in effector cells might compensate for decreased immune functions of these cells in vivo when transplanted into patients. These results suggest a decreased immune function in G-CSF-mobilized BSC harvests and warrant further studies to correlate these data with clinical outcome.

Bovine mammary immune response to an experimental intramammary infection with a Staphylococcus aureus strain containing a gene for staphylococcal enterotoxin C1

Staphylococcal enterotoxin C (SEC), a superantigen, is the most frequently expressed enterotoxin by bovine strains of Staphylococcus aureus causing mastitis. To examine the possible impact of SEC on the immune response of the bovine mammary gland, we monitored changes in lymphocyte subpopulations in mammary glands of four lactating cows after intramammary instillation of S. aureus strain Rn4220 transformed with a plasmid containing a gene coding for SEC1. Four other lactating cows received the same strain transformed with the plasmid without the SEC1 gene (positive control), and four cows were untreated (negative control). Mammary quarter milk samples for somatic cell count (SCC) analysis and determination of N-acetyl-beta-D-glucosimindase (NAGase) activity levels were collected daily for 21 d postinstillation. Flow cytometry utilizing three-color analysis was used to phenotype lymphocyte subpopulations isolated from milk samples collected on d 0, 4, 7, 11, 14, 18, and 21 postinstillation from all the cows. Milk from mammary gland halves (positive control and experimental) or all mammary quarters (negative control) was collected for flow cytometric analysis. Increased NAGase activity, SCC, and isolated S. aureus demonstrated that infection was established in mammary quarters intrammarily instilled with bacteria. There were no significant differences (P > 0.05) in the proportions of BoCD4 helper T lymphocytes or BoCD8 cytotoxic T lymphocytes between the two infected treatment groups. There was a significant day x treatment difference of the proportion of a gammadelta T cell subpopulation that did not express BoCD2, but did express the ACT2 activation molecule and a significant treatment difference of a gammadelta T cell subpopulation that expressed BoCD2, but not the ACT2 activation molecule (P < 0.05). Results do not support the hypothesis that the presence of the gene for SEC1 alters the mammary BoCD4 or BoCD8 T lymphocyte response to infection.

Lsc is required for marginal zone B cells, regulation of lymphocyte motility and immune responses

Lsc (the murine homolog of human p115 Rho GEF) is a member of the Dbl-homology family of GTP exchange factors and is a specific activator of Rho. Lsc is activated by the G alpha(13) subunit of heterotrimeric G proteins and contains a regulator of G protein signaling domain that downmodulates G alpha(12) and G alpha(13). Lsc is expressed primarily in the hematopoietic system and links the activation of G alpha(12) and G alpha(13)-coupled receptors to actin polymerization in B and T cells. Lsc is essential for marginal zone B (MZB) cell homeostasis and for the generation of immune responses. Although Lsc-deficient lymphocytes show reduced basal motility, MZB cells show enhanced migration after serum activation. Thus, Lsc is a critical regulator of MZB cells and immune functions.

Alterations induced by chronic stress in lymphocyte subsets of blood and primary and secondary immune organs of mice

BACKGROUND

The immune system is particularly sensitive to stress. Although acute stress generally has positive effects, chronic stress typically provokes immunosuppression. The elucidation of the mechanisms involved in immunosuppression are of interest for the design of therapeutic approaches to avoid the appearance of stress disorders. This study aimed to investigate chronic stress-induced alterations on lymphocyte subset distribution and percentages. The experiments were performed with C57BL/6 mice subjected to chronic immobilization stress.

RESULTS

Stress caused a marked increase in apoptosis inside the thymus, and a reduction in the total number of thymocytes. Furthermore, the proportion of immature thymocytes declined significantly suggesting that the increased apoptosis mainly affected cells of immature phenotype. In blood, the total number of lymphocytes diminished but not all lymphocyte populations showed the same tendency: while the relative proportion of B cells declined slightly, the relative proportion of circulating CD3+ cells, and particularly some T cell subsets showing an immature phenotype (CD3+PNA+), increased under stress. The spleen and lymph nodes show a marked reduction in cellularity, but the relative proportion of T cells increased, while no change or only a slight reduction was observed in the relative proportion of B cells. Similarly, the relative proportion of T cells increased in bone marrow.

CONCLUSIONS

Detailed data on the alterations of lymphoid cell subsets occurring under immobilization stress, both in the bloodstream and in different lymphoid tissues, are obtained. In general, T cells are more affected than B cells and, in particular, a marked increase in the percentage of a subset of circulating PNA+CD3+ T cells is observed.

Short-term hyperglycemia induces lymphopenia and lymphocyte subset redistribution

Alterations in lymphocytes are a common finding in both type I and type II diabetes. Autoimmune phenomena in type I diabetes, the stage of the diabetic disorder and metabolic effects of therapeutic interventions may also affect actual distribution of lymphocyte phenotypes. This study investigated immunological effects specific to standardized hyperglycemia in non-diabetic individuals to exclude immunological changes potentially related to diabetes stage and treatment. 37 subjects (mean age +/- SD 39 +/- 5 years) underwent a sequence-controlled crossover with oral administration of a solution containing either 75 g glucose or artificial sweetener (i.e. placebo). At rest and at two hours, counts of white blood cells (WBC), mixed lymphocytes, mature T-cells (CD3), T-helper cells (CD4), T-suppressor/ cytotoxic cells (CD8), B-cells (CD19), natural killer cells (CD16/CD56), and interleukin-2 receptor bearing peripheral blood mononuclear cells (CD25) were measured by flow cytometry. Subjects showed a significant decrease in WBC, lymphocytes, and all lymphocyte subsets with the OGTT compared with the placebo solution (p < .05 to p < .001). In non-diabetic individuals, short-term hyperglycemia induces immunological changes that may be relevant to explain similar findings in patients with diabetes mellitus. Future studies need to validate these findings and their potential clinical implications in a diabetic population.

Standardized flow cytometry gating in veterinary medicine

Gating in flow cytometry is used to select subpopulations of cells for analysis. The technique is critical for subsequent analysis in order to select the population, free of debris and unrelated cells. Accurately quantifying subpopulations in clinical cases is necessary for correct diagnosis. Human lymphocytes are selected by backgating on populations of CD45+high CD14- cells. These reagents are not available widely across species. In veterinary medicine, markers to identify lymphocytes are usually limited to T-lymphocyte, CD4, CD8, and B-lymphocyte surface antigens. A standardized gating technique using a T-lymphocyte antibody is described and is applicable across species where limited phenotype markers are available.

Changes in human lymphocyte subpopulations in tonsils and regional lymph nodes of human head and neck squamous carcinoma compared to control lymph nodes

BACKGROUND

Lymphoid tissues constitute basic structures where specific immune responses take place. This leads to the development of germinal centres (GCs), migration of cells and the generation of memory cells. Here, we have compared human tumour reactive lymph nodes and tonsils with control lymph nodes.

RESULTS

The study by flow cytometry shows that in control lymph nodes the majority of cells were naive T-lymphocytes (CD45RA+/CD7+). In reactive nodes, although the percentage of CD45RO+ T cells remains constant, there is an increase in the number of B-lymphocytes, and a reduction in naive T cells. The percentage of cells expressing CD69 was similar in reactive nodes and in controls. In both cases, we have found two populations of B cells of either CD69- or CD69dull. Two populations of T cells, which are either negative for CD69 or express it in bright levels (CD69bright), were also found. The analysis of tissue sections by confocal microscopy revealed differences between control, tonsils and tumor reactive lymph nodes. In control lymph nodes, CD19 B cells are surrounded by a unique layer of CD69bright/CD45RO+ T cells. GCs from tonsils and from tumour reactive nodes are mainly constituted by CD19 B cells and have four distinct layers. The central zone is composed of CD69- B cells surrounded by CD69bright/CD45RO+ T cells. The mantle region has basically CD69dull B-lymphocytes and, finally, there is an outer zone with CD69-/CD45RO+ T cells.

CONCLUSIONS

Human secondary lymphoid organs react with an increase in the proportion of B lymphocytes and a decrease in the number of CD45RA+ T cells (naive). In tonsils, this is due to chronic pathogen stimulation, whereas in lymph nodes draining head and neck carcinomas the reaction is prompted by surrounded tumors. During this process, secondary lymphoid organs develop secondary follicles with a special organization of T and B cells in consecutive layers, that are described here by confocal microscopy. This pattern of cellular distribution may suggest a model of cell migration into the secondary lymphoid follicles.

[Phenotype of alveolar lymphocytes--theoretical and practical implications]

Actual characteristics of alveolar lymphocytes was presented, including author's own experience, i.e. bronchoalveolar lavage (BAL) lymphocyte typing in over 450 patients with interstitial lung diseases (ILD) and bronchial asthma. In healthy individuals as well as in the patients, alveolar lymphocyte population is dominated by T cell subset. Alveolar T lymphocytes present primed memory cell phenotype and usually do not proliferate; in normal conditions apoptosis occurs very seldom. T cytotoxic cell phenotype is characteristic for CD8 subset. Percent of B and NK cells found in BAL is very low--B cells are localized in interstitial space around the pulmonary alveoli, while NK cells do not seem to play the important role in the local pulmonary defense. CD4/CD8 ratio evaluation in BAL material is an auxiliary tool in ILD diagnostics; it reflects local imbalance between T helper primed memory cells and primed T cytotoxic cells.

Effects of BCG on ovalbumin-induced bronchial hyperreactivity in a guinea pig asthma model

To test the effects of Bacillus Calmette-Guérin (BCG) on ovalbumin (OVA)-induced airway hyper-reactivity in guinea pigs, a total of 40 young guinea pigs was individually vaccinated subcutaneously with 0.2 mL of 2% OVA, 50 microg BCG, or a mixture of OVA and BCG (OVA+BCG). Airways were sensitized using nebulization with 1% OVA for 3 min once a week for two applications, followed by 2% OVA nebulized challenge for 3 min 1 week after the last application. Different concentrations of methacholine were used to detect airway hyperreactivities. At the third week, the guinea pigs were nebulized with either methacholine or OVA to test airway hyperreactivity. The OVA-vaccinated group presented with severe airway hyperresponsiveness after OVA and methacholine challenges; the BCG-vaccinated group showed mild airway hyperreactivity; and the OVA+BCG group showed the least amount of airway hyperreactivity. Lung histopathology in all groups, except the OVA+BCG-vaccinated group, showed severe thickening of the alveolar walls which became firmly fibrotic, and narrowing of the alveolar spaces was also noted. The guinea pigs in the OVA+BCG-vaccinated group had similar pulmonary morphology with that of naive guinea pigs, and had mild cell infiltration in the alveolar wall. The results of the skin biopsies at 6 h (2% OVA, 0.05 mL) and 36 h (20 microg PPD, 0.05 mL) after purified protein derivative (PPD) inoculation showed that infiltration of eosinophils and activation of CD4+ T-cells occurred in the OVA-vaccinated group. In the BCG-vaccinated groups, infiltration of CD4+ T-cells, CD8+ T-cells and macrophages occurred. OVA-specific IgG2 increased in the BCG-vaccinated groups after OVA-induced airway hyperreactivity occurred. The peripheral cell subpopulation showed that there was obviously increased activation of CD4+ and CD8+ T-cells in the OVA+BCG-vaccinated group. The phagocytic activity of macrophages also increased in both BCG- and OVA+BCG-vaccinated groups. The prevention of OVA-induced airway hyperreactivities using BCG vaccination in conjugation with OVA in these young guinea pigs indicated that it might be a good approach to avoid allergic reactions in humans.

Bonzo/CXCR6 expression defines type 1-polarized T-cell subsets with extralymphoid tissue homing potential

Chemokine receptor expression is finely controlled during T-cell development. We show that newly identified chemokine receptor Bonzo/CXCR6 is expressed by subsets of Th1 or T-cytotoxic 1 (Tc1) cells, but not by Th2 or Tc2 cells, establishing Bonzo as a differential marker of polarized type 1 T cells in vitro and in vivo. Priming of naive T cells by dendritic cells induces expression of Bonzo on T cells. IL-12 enhances this dendritic cell-dependent upregulation, while IL-4 inhibits it. In blood, 35-56% of Bonzo+ CD4 T cells are Th1 cells, and 60-65% of Bonzo+ CD8 T cells are Tc1 cells, while few Bonzo+ cells are type 2 T cells. Almost all Bonzo+ Tc1 cells contain preformed granzyme A and display cytotoxic effector phenotype. Most Bonzo+ T cells lack L-selectin and/or CCR7, homing receptors for lymphoid tissues. Instead, Bonzo+ T cells are dramatically enriched among T cells in tissue sites of inflammation, such as rheumatoid joints and inflamed livers. Bonzo may be important in trafficking of effector T cells that mediate type 1 inflammation, making it a potential target for therapeutic modulation of inflammatory diseases.

Interferon-inducible protein 10, monokine induced by interferon gamma, and interferon-inducible T-cell alpha chemoattractant are produced by thymic epithelial cells and attract T-cell receptor (TCR) alphabeta+ CD8+ single-positive T cells, TCRgammadelta+ T cells, and natural killer-type cells in human thymus

Strong reactivity for interferon-inducible protein 10 (IP-10), monokine induced by interferon gamma (Mig), and interferon-inducible T-cell alpha chemoattractant (I-TAC) was found in epithelial cells mainly localized to the medulla of postnatal human thymus. The CXC chemokine receptor common to the 3 chemokines (CXCR3) was also preferentially expressed in medullary areas of the same thymuses and appeared to be a property of 4 distinct populations: CD3+ T-cell receptor (TCR) alphabeta+ CD8+ single-positive (SP) T cells, TCRgammadelta+ T cells, natural killer (NK)-type cells, and a small subset of CD3+(low) CD4+ CD8+ TCRalphabeta+ double-positive (DP) T cells. IP-10, Mig, and I-TAC showed chemoattractant activity for TCRalphabeta+ CD8+ SP T cells, TCRgammadelta+ T cells, and NK-type cells, suggesting their role in the migration of different subsets of mature thymocytes during human thymus lymphopoiesis.

Characterization of novel natural killer (NK)-cell and gammadelta T-cell lines established from primary lesions of nasal T/NK-cell lymphomas associated with the Epstein-Barr virus

Studies on nasal T/natural killer (NK)-cell lymphoma have been hampered by its tendency to cause necrosis. Thus, the establishment of cell lines of this neoplasm would seem to be valuable. This study attempted to establish cell lines from primary lesions of this tumor, and successfully obtained 2 novel Epstein-Barr virus (EBV)-positive cell lines, SNK-6 and SNT-8, by means of high-dose recombinant interleukin 2. Flow cytometry showed that SNK-6 had an NK-cell phenotype, CD3- CD4- CD8- CD19- CD56+ T-cell receptor (TCR) alpha/beta- TCR gamma/delta-, whereas SNT-8 was CD3+ CD4- CD8- CD19- CD56+ TCR alpha/beta- TCR gamma/delta+. These were consistent with immunophenotypes of their original tumors, and the cell lines had monoclonal EBV clones identical to ones in their original tumors. Thus, the cell lines developed from cells forming the primary lesions. Genotypic analysis showed that SNK-6 had unrearranged TCR and immunoglobulin heavy-chain genes, supporting the conclusion that SNK-6 was of NK-cell lineage. On the other hand, SNT-8 had rearranged TCR beta-, gamma-, and delta-chain genes, and together with its phenotype, SNT-8 proved to be a gammadelta T-cell line. This is the first report of the establishment of cell lines from primary lesions of nasal T/NK cell lymphomas, and the results demonstrated that there are at least 2 lineages, NK- and gammadelta T-cell, in this neoplasm. Moreover, it has been suggested that nasal T/NK cell lymphomas of these lineages may belong to the same clinicopathologic entity because both types of cases shared common clinical and histopathologic features.

Macrophages and lymphocyte subpopulations in nifedipine- and cyclosporin A-associated human gingival overgrowth

BACKGROUND

Nifedipine and cyclosporin A (CsA) induce gingival overgrowth. Both drugs have immunomodulating effects. It has been suggested that altered immune response is associated with drug-induced gingival overgrowth. In this study, we evaluated whether there were differences in macrophages and lymphocyte subpopulations in human nifedipine- and CsA-associated gingival overgrowth as compared with those in normal gingiva.

METHODS

Biopsy samples of overgrown gingiva were obtained from 9 nifedipine-treated cardiac outpatients, 13 CsA-treated renal transplant recipients including 9 patients who were also receiving nifedipine, and 30 healthy control individuals undergoing dental treatment. Serial 5 microm thick cryostat sections were stained with mAbs for CD20 (B-pan), CD68 (macrophages), CD4 (T-helper/inducer), and CD8 (T-cytotoxic/suppressor) using an avidin-biotin-horseradish peroxidase complex method. Numbers of mAb-labeled and all nucleated cells were determined in 3 areas: the connective tissue beneath the sulcular epithelium, the middle connective tissue, and the connective tissue beneath the oral epithelium. Distributions of each type of cell were expressed as percentages of mAb-labeled cells in relation to total number of nucleated cells in a counting zone. Significances of differences between groups were tested by means of the Kruskal-Wallis test, and between pairs of results by means of the Mann-Whitney U-test.

RESULTS

The proportion of CD8-labeled cells was significantly higher in connective tissue beneath the sulcular epithelium in the nifedipine group than in the controls (P = 0.014). In both medicated groups, the proportions of CD68-labeled cells were higher in all counting zones than in the controls, but statistically significantly only in the nifedipine group in the connective tissue beneath the oral epithelium (P = 0.008). No intergroup differences were found with respect to CD4- and CD20-labeled cells. The CD4/CD8 ratio was significantly lower in connective tissue beneath the sulcular epithelium in the nifedipine group than in the controls (P= 0.013).

CONCLUSION

The results support the idea that immune response may be altered in drug-induced gingival overgrowth.

Gamma/delta T cell response of chickens after oral administration of attenuated and non-attenuated Salmonella typhimurium strains

Poultry represents an important source of Salmonella infection in man. Despite intensive research on immunity, little is known about the involvement of T cell sub-populations in the immunological response of chickens against infection with non-host-adapted Salmonella (S.) serovars. In this study, the T cell composition of blood lymphocytes (CD4(+)CD8(+); CD4(+)CD8(-); CD4(-)CD8(+); CD8(+)TcR1(+); CD8(-)TcR1(+), CD8(+)TcR1(-)) after oral administration of the non-attenuated S. typhimurium wild-type strain 421 (infection) or the attenuated vaccine strain Salmonella vac((R)) T (immunization) to day-old chicks was investigated and compared with non-treated chickens by flow cytofluorometry. Additionally, the occurrence of T cell sub-populations (CD4(+); CD8(+); TcR1(+)(gammadelta); TcR2(+)(alphabeta(1))) in ceca, spleen and bursa of Fabricius of the birds was studied immunohistologically. Blood samples and tissues were examined between days 1 and 12 of age. Chicks inoculated with S. typhimurium 421 or Salmonella vac((R)) T showed significantly elevated percentages of CD8(+)TcR1(+) in blood on days 7, 8 and 9, or on day 8 in comparison to control animals. The CD4 to CD8 cell ratio was about 3:1 in infected animals on day 5 of age. In the organs of treated chicks the numbers of CD8(+)(gammadelta) and TcR1(+)(gammadelta) cells had markedly increased on days 4 and 5 in ceca, 8 and 9 in the bursa and 9 and 12 in the spleen. Moreover, infected or vaccinated birds revealed larger quantities of CD4(+) and TcR2(+) T cells in ceca on days 4 and 5. As shown by double staining, the TcR1(+) cells in the organs of infected animals additionally carried the CD8 antigen. In conclusion, immunization of day-old chicks with the attenuated Salmonella live vaccine strain resulted in the same changes in T cell composition as seen after infection with the non-attenuated Salmonella wild-type strain, but at a lower level. The remarkable increase of CD8(+)TcR1(+)(gammadelta) double positive cells in treated birds indicates an important role of this cell sub-population in the immunological defense of chickens against Salmonella exposure.

Granulocyte/macrophage-colony-stimulating-factor plus interleukin-2 plus interferon alpha in the treatment of metastatic renal cell carcinoma: a pilot study

Granulocyte/macrophage-colony-stimulating factor (GM-CSF) plays a central role in the differentiation and function of dendritic cells, which are crucial for the elicitation of MHC-restricted T cell responses. Preclinical and the first clinical data provide a rationale for the application of GM-CSF in immunotherapy of cancer. Ten patients with renal cell carcinoma stage IV (Holland/ Robson) were treated in this pilot study. Therapy was started with GM-CSF alone (2 weeks). Interleukin (IL-2) and interferon alpha (IFNalpha) were added sequentially (3 weeks GM-CSF plus IL-2 or IFNalpha, 3 weeks GM-CSF plus IL-2 plus IFNalpha). Therapy was performed on an outpatient basis. The cytokine regimen was evaluated for toxicity, clinical response and immunomodulatory effects [fluorescence-activated cell sorting analysis of peripheral blood mononuclear cells (PBMC), mixed-lymphocyte reaction and cytotoxicity of PBMC]. GM-CSF treatment caused a significant increase in the number of PBMC expressing costimulatory molecules. Addition of IL-2 and IFNalpha led to an increase in CD3 , CD4+, CD8+ and CD56+ PBMC in week 9. In an autologous mixed-lymphocyte reaction a 2.1-fold increase in T cell proliferation was observed after 2 weeks of GM-CSF treatment, and cytotoxicity assays showed changes in natural-killer-(NK)- and non-NK-mediated cytotoxicity in some patients. Two patients achieved partial remission, one patient had a mixed response. The toxicity of the regimen was mild to moderate with fever, flu-like symptoms and nausea being observed in most patients. Severe organ toxicity was not observed. We conclude that GM-CSF might be useful for immunotherapy of renal cell carcinoma, especially in combination with T-cell-active cytokines. Further studies are warranted.

Clinical and immunological features of patients with interleukin-5-producing T cell clones and eosinophilia

Recent work suggests that in some patients with the hypereosinophilic syndrome, a clone of abnormal T cells produces large amounts of interleukin-5. In this study, we examined 60 patients with idiopathic eosinophilia. Sixteen patients had circulating T cells with an aberrant immunophenotype that, in most cases, were associated with different forms of skin inflammation. The abnormal T cells produced large amounts of interleukin-5, which may have increased eosinophil differentiation in the bone marrow of these patients.

Clinical application of four and five-color flow cytometry lymphocyte subset immunophenotyping

A 1995 survey of clinical flow cytometry laboratories in the United States determined that 63% of clinical laboratories used one or two-color, 33% used three-color, 4% used four-color, and none used five-color panels. We show the feasibility and advantages of acquiring routine clinical four-color, six-parameter and five-color, seven-parameter analysis on blood samples derived from a pediatric population. The panels were evaluated by comparing the following cell characteristics: size, internal structure, and up to five distinct fluorochrome-conjugated antibodies to cell surface antigens: CD3, CD16+CD56, CD19, CD8, and CD4. These samples were processed on a commercially available instrument without any special modifications. A comparison of two-color and four-color as well as four-color and five-color panel analysis showed no statistical difference between the groups. We propose that the five-color, single-tube panel will (1) eliminate the need for isotype controls; (2) the relative proportions of lymphocyte subpopulations may be used to validate the operator-defined window, replacing CD45; (3) eliminate the need to run a common factor, in order to establish and maintain a reproducible lymphocyte window between tubes; and (4) create a more complete clinical picture by generating 32 unique, mutually exclusive phenotypes (permutations). Our results show that it is feasible to acquire and integrate seven-parameter data. This may be a powerful tool for immunophenotyping cells in a modern clinical diagnostic cytometry laboratory.

Adhesion molecules on peripheral blood lymphocyte subpopulations in the elderly

Adhesion molecules, such as CD49d, CD50 and CD62L, have important roles in many adhesive interactions involving cells of the immune system. Since it has been shown that many immunological alterations are present in aged subjects, we studied, by means of triple colour whole blood immunostaining and multiparametric flow cytometry, the expression and intensity level (MFI) of these molecules on peripheral blood lymphocyte subpopulations from 23 healthy elderly subjects and 13 young controls. In the elderly a decrease in total peripheral blood lymphocytes bearing CD62L antigen was observed (39 +/- 13% vs 63 +/- 6% and 745 +/- 312/mm3 vs 1,393 +/- 407/mm3; p<0.001), whereas the numbers of lymphocytes expressing CD49d and CD50 antigens were comparable in aged and young subjects. In addition, CD50 and CD62L MFI values on total peripheral blood lymphocytes were higher in elderly than in young subjects (5.23 +/- 1.03 vs 4.18 +/- 0.44, p = 0.001 and 2.60 +/- 0.35 vs 2.21 +/- 0.40, p = 0.005 respectively) while the intensity expression of CD49d was unchanged. The percentages and absolute numbers of T and B lymphocytes expressing CD62L were decreased in elderly compared to young subjects (CD62L+CD3+: 43 +/- 15% vs 66 +/- 9% and 581 +/- 257/mm3 vs 1,028 +/- 418/mm3, p<0.001; CD62L+CD19+: 78 +/- 12% vs 90 +/- 4%, p < 0.005 and 103 +/- 64/mm3 vs 207 +/- 98, p < 0.001). A decrease in the proportion of CD62L bearing NK cells was also observed in the elderly (25 +/- 14% vs 46 +/- 24%, p<0.005), although their absolute number was unchanged. No significant differences were detected in the proportion of T, B and NK lymphocytes expressing CD49d and CD50 antigens and only the absolute numbers of B cells expressing these adhesion molecules were lower in elderly (CD49d+CD19+: 121 +/- 71/mm3 and CD50+CD19+: 107 +/- 73/mm3) compared to young donors (CD49d+CD19+: 248 +/- 112/mm3 and CD50+CD19+: 235 +/- 120/mm3, p < 0.001). Moreover, the intensity of adhesion molecule expression was differentially modulated in the elderly depending on the specific lymphocyte cell population considered. The densities of CD49d, CD50 and CD62L antigens on B and NK lymphocytes from the two age groups were not different; on the contrary, T lymphocytes from elderly donors exhibited increased CD49d (1.69 +/- 0.09 vs 1.62 +/- 0.07, p < 0.05), CD50 (4.98 +/- 1.16 vs 3.77 +/- 0.46, p < 0.001) and CD62L (2.26 +/- 0.38 vs 1.99 +/- 0.37, p < 0.05) MFI values compared to young donors.

Cytokine analysis at the single cell level and lymphoproliferative responses to mycobacterial antigens in HIV-1 patients with successful virologic response to potent antiretrovirals

Immunologic parameters, known to be grossly abnormal in HIV-1-infected subjects, were analyzed in 22 patients with sustained viral load suppression (<200 copies/ml) following long-term highly active antiretroviral therapy (HAART). Responses were compared with those from 18 HIV-seronegative healthy controls. Persistent phenotypic alterations in patients' blood mononuclear cells were minimal, though the percentages of lymphocytes that could be activated to produce interleukin-2 (IL-2) remained severely depressed. Using lymphoproliferative assays, a striking deficit in the capacity of patients to respond to the common mycobacterial antigens and particularly to recombinant heat-shock proteins paralleled the absence of responses to virus p24 antigen. In view of the important immunoregulatory role of stress proteins, these findings reveal profound functional deficiencies and persistent immune dysregulation in HIV-1 patients, despite successful HAART and a considerable recovery of CD4+ lymphocyte numbers. Rational immunotherapeutic approaches should be aimed to correct the characterized immune abnormalities.

Low in vitro production of interferon-gamma and tumor necrosis factor-alpha in HIV-seronegative patients with pulmonary disease caused by nontuberculous mycobacteria

We studied 32 HIV-seronegative patients with pulmonary disease caused by nontuberculous mycobacteria (NTM). Immunologic studies included lymphocyte subset analysis by flow cytometry, measurement of interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) production following in vitro stimulation of diluted whole blood (DWB) and peripheral blood mononuclear cells (PBMC) by phytohemagglutinin (PHA), anti-CD3 as well as purified protein derivative of tuberculin (PPD), and in four cases with different amounts of the very mycobacterium, which caused disease in these patients. Data were compared to those of 30 HIV-seronegative patients with disease by Mycobacterium tuberculosis (MTb). Following alpha-CD3-stimulation of PBMC, NTM patients showed lower IFN-gamma (P < 0.00005) and lower TNF-alpha (P < 0.02). For a subgroup of tuberculin skin test-positive NTM patients we found significantly lower PPD-induced IFN-gamma releases in cultured DWB (P < 0.0002) and PBMC (P < 0.0004) compared to MTb patients. Data for PPD-induced TNF-alpha release for this subgroup were also significant (P < 0.001 and P < 0.05, respectively). The four NTM patients with poor PPD-induced IFN-gamma response hardly showed increased cytokine production on stimulation with their specific mycobacterium. The lower production capacity of IFN-gamma and TNF-alpha of NTM patients compared to the MTb patients points to an immunologic imbalance forming the basis for their increased susceptibility to pulmonary infections by nontuberculous mycobacteria.

Umbilical cord blood transplantation in severe T-cell immunodeficiency disorders: two-year experience

Hematopoietic stem cell transplantation is the treatment of choice for severe primary T-cell immunodeficiencies. When an HLA-identical sibling as the donor is not available, an alternative donor stem cell source is needed. In primary T-cell immunodeficiencies, T-cell-depleted HLA-haploidentical bone marrow transplantation has been particularly successful in reconstituting the immune system in many but not all of the severe T-cell immune deficiency disorders. This study reports the use of umbilical cord blood (UCB) stem cell transplantation in severe T-cell immune deficiency. Umbilical cord blood was evaluated as a stem cell source for immune reconstitution in children with severe primary T-cell immunodeficiency disorders, such as severe combined immunodeficiency syndrome (SCID), reticular dysgenesis, thymic dysplasia, combined immunodeficiency disease (CID), and Wiskott-Aldrich syndrome (WAS) when a matched sibling donor was unavailable. From 1/96 through 5/98, eight children received unrelated cord blood stem cell transplantation following a preparative regimen for the treatment of combined immunodeficiency diseases. The patients ranged in age from 2 weeks to 8 years. The cord blood units were 3/6 HLA antigen matches in two children. 4/6 in four children, and 5/6 in two child, with molecular HLA-DR mismatch in three of the children. The average time for neutrophil engraftment (absolute neutrophil count >500/mm3) was 12 days (range 10-15 days) and the average time for platelet engraftment (platelet count >20,000/mm3) was 36 days (range 24-50 days). A patient with reticular dysgenesis failed to engraft following her first transplant, but fully engrafted after a second unrelated donor cord blood transplantation. Five of six patients exhibited grade I graft-versus-host disease (GvHD). while one child had grade IV skin and gut GvHD. Immunologic reconstitution demonstrated that cord blood stem cell transplantation resulted in consistent and stable T-, B- and natural killer (NK) cell development. The kinetics of development were such that T-cell development occurred between 60 to 100 days. Initial T-cell engraftment consisted predominantly of CD45RO+, CD3+, and CD4+ T cells, and at 12 to 24 months changed to CD45RA+, CD3+, and CD4+ T cells, indicating de novo maturation of T cells. NK cell development occurred at approximately 180 days. B cells engrafted early, and study of functional B-cell antibody responses revealed that five of six patients in whom intravenous immune globulin has been discontinued have low detectable antibody responses to tetanus and diphtheria toxoid immunizations at 18 to 24 months posttransplantation. Unrelated umbilical donor cord blood is an alternative source of stem cells for transplantation in children with severe T-cell immune deficiency disorders when a suitable HLA-matched donor is not available and when a T-depleted haploidentical preparation is not beneficial. Benefits of UCB include rapid and reliable recovery of immune function, low risk of GvHD, and low viral transmission rate.

Lymphocyte subset changes in blood and gastrointestinal mucosa after oral nickel challenge in nickel-sensitized women

This study investigates lymphocyte subsets in both the gastrointestinal mucosa and blood, in patients with nickel allergic contact dermatitis, after 10 mg oral nickel challenge (double-blind, placebo-controlled). 6 such patients with cutaneous symptoms induced only by skin contact with nickel (group A), 6 with a flare-up of cutaneous symptoms after food nickel ingestion (group B) and 6 healthy controls (group C) were enrolled. Blood lymphocyte subsets (CD4, CD45RO, CD8) were analyzed before and after 4 and 24 h from the challenge (test 1, 2, and 3), and intestinal biopsies were performed 2 days later. Challenges were positive in group B and negative in group A and controls. Serum and urine nickel levels significantly increased after nickel ingestion, with no differences between the 3 groups. At test 3, a significant decrease of the all CDs studied was found in group B. Biopsies of this group showed higher levels of CD45RO+ cells in the lamina propria and in the epithelium and lower levels of epithelial CD8+ lymphocytes. This study confirms that ingested nickel may induce flare-up of cutaneous reactions in some nickel-allergic patients, independently of the degree of sensitization and the intake of metal. In these patients, oral nickel stimulates the immune system, inducing maturation of T lymphocytes from virgin into memory cells; these latter cells seem to accumulate in the intestinal mucosa. The immunoreaction also involves CD8+ cells, whose role is not yet clear.

A single measurement of CD38CD8 cells in HIV+, long-term surviving injecting drug users distinguishes those who will progress to AIDS from those who will remain stable

This study compares the predictive power of a single measurement of CD8+CD38+, CD8+CD45RO+ or CD8+CD38+CD45RO+ subpopulations in predicting progression to AIDS in a cohort of HIV+ long-term surviving injecting drug users. The results showed that both the total CD8+ percentage, and the CD8+CD38+ and CD8+CD38+CD45RO+ subpopulations of cells all individually predicted progression to AIDS. In combination with CD4, only the CD8+CD38+ subpopulation enhanced the predictive power of the CD4 percentage alone. The CD8+ percentage correlated negatively with the CD4 percentage and the CD8+CD45RO+ subpopulation did not predict disease progression. The proportion of CD8+CD38+ cells identified which patients with a moderate CD4 level were more likely to progress to AIDS, and conversely, which patients with a low CD4 count were likely to remain clinically stable. The results were consistent irrespective of whether time was measured from the date of seroconversion, or from the date of the test. This study is the first to measure these markers in HIV-infected injecting drug users, and in long-term survivors. The results demonstrate the considerable added value of the CD8+CD38+ cell percentage over the CD4 count alone, in predicting HIV clinical progression.

Cytokines secreted by lymphokine-activated killer cells induce endogenous nitric oxide synthesis and apoptosis in DLD-1 colon cancer cells

IL-2-activated killer lymphocytes (LAK cells) secrete inflammatory cytokines such as interferon-gamma (IFN-gamma) and tumor necrosis factor alpha (TNFalpha) that can induce nitric oxide (NO) synthesis. We evaluated whether LAK cells could activate NO synthesis in human cancer cells. LAK cells and their culture supernatants induced NO synthesis in DLD-1 colon cancer cells in a dose-dependent manner. NO synthesis was inhibited completely by blocking antibodies to IFN-gamma, demonstrating a key role for this LAK cell cytokine in regulating NO synthesis. The addition of TNFalpha antibodies resulted in partial inhibition. Induction of iNOS mRNA and protein expression in DLD-1 cells was detected. Endogenous NO production inhibited DLD-1 cell proliferation and induced apoptosis, processes that were inhibitable by the NO synthase inhibitor N(G)-monomethyl-l-arginine. Our study has identified a novel, non-contact-dependent LAK cell cytotoxic mechanism: induction of growth inhibition and programmed cell death due to endogenous NO synthesis in susceptible human cancer cells.

Discrimination of different subsets of cytolytic cells in pseudorabies virus-immune and naive pigs

We previously observed that pseudorabies virus (PRV)-induced, cell-mediated cytolysis in pigs includes killing by natural killer (NK) cells. We also observed that IL-2 stimulation in vitro of naive PBMC expands porcine NK cells. The purpose of this study was to compare the phenotypes of the cytolytic subsets stimulated in vitro by PRV and by IL-2. PBMC were isolated from blood of PRV-immune and naive pigs and stimulated in vitro with PRV or IL-2. After 6 days, the frequency of various lymphocyte subsets in these cultured PBMC was determined by flow cytometry: the cells were separated with a magnet-activated cell sorter and the cytolytic activity of the separated populations was determined. When lymphocytes were separated and analysed with FACScan, the following lymphocyte subsets were discriminated: CD6(+) CD8(bright+) CD4(-) (CTL phenotype), CD6(+) CD8(dull+) CD4(+) (the fraction containing memory T helper cells), CD6(+) CD8(-) CD4(+) (T helper cell phenotype), CD6(-) CD8(dull+) CD4(-) gammadelta-T(+) ( gammadelta-T cell phenotype), CD6(-) CD8(dull+) CD4(-) gammadelta-T(-) (NK phenotype) and CD6(-) CD8(-) CD4(-) gammadelta-T(-) or gammadelta-T(+). Flow cytometry analysis demonstrated that PRV stimulation of immune PBMC resulted in the occurrence of more CD6(+) CD8(+) and CD4(+) CD8(+) and fewer CD6(-) CD8(+) and gammadelta-T(+) CD8(+) lymphocytes than IL-2 stimulation of naive PBMC (P<0.05). It was demonstrated further that killing by PRV-stimulated PBMC was mediated mainly by CD6(+) CD8(+) T lymphocytes. Killing by IL-2-stimulated PBMC was mediated mainly by CD6(-) CD8(+) T lymphocytes. These results demonstrate that both natural killing and killing by classical PRV-specific CTL were detected in PRV-immune pigs, whereas IL-2 stimulation of PBMC isolated from naive pigs mainly induced natural killing.

Identification of Ostertagia ostertagi specific cells in bovine abomasal lymph nodes

To investigate the contribution of different bovine cell subpopulations in the development of in vitro induced responses by Ostertagia ostertagi third larval antigen extract (L3), bovine abomasal lymph node cell suspensions were depleted of specific cell populations. The depleted cell suspensions were subsequently assayed for their proliferative responses to O. ostertagi L3 antigen extract. Proliferative responses to O. ostertagi L3 antigen extract were restricted to a CD2+ CD4- CD8- cell population and MHC II+ cells different from B-cells were of major importance. Depletion of CD4, CD8, CD4CD8, IgM or CD21 positive cells did not decrease proliferation to L3 antigen extract. Depletion of gammadelta T-cells, which also comprise a subpopulation of CD2+ CD4- CD8- cells, reduced proliferation to L3 antigen extract only in one animal. The results suggest that either gammadelta T-cells could be involved in the proliferation or that another as yet unidentified population is important for proliferation. The precise role of these populations during infection with O. ostertagi and the mechanism by which these cells may influence the host immune response are important issues that remain to be elucidated.

Antioxidant administration inhibits exercise-induced thymocyte apoptosis in rats

PURPOSE

The purpose of this study was to investigate the effect of antioxidant on exercise-induced apoptosis in rat thymocytes.

METHODS

After exercise at 13.8 m x min(-1) for 60-90 min x d(-1) on a motor-driven drum exerciser for 2 consecutive days, rat thymocyte apoptosis was monitored by the feature of DNA fragmentation. To study the effect of antioxidant, rats were administered with butylated hydroxyanisole (BHA) for 7 d before exercise.

RESULTS

Exercise could induce thymocyte DNA fragmentation as detected on electrophoretic gel and by cell death detection ELISA kit. Further studies indicated that pretreatment with antioxidant BHA to rats resulted in a blockage of exercise-induced DNA fragmentation. The concentrations of glutathione (GSH) were not significantly changed in rat thymocytes after exercise with or without BHA treatment.

CONCLUSION

These results suggest that reactive oxygen species may play a role in thymocyte apoptosis induced by exercise. However, changes in GSH levels were not observed in this exercise model.

The influence of age and breeding conditions on the number and proliferation of intraepithelial lymphocytes in pigs

The number and subset composition of intraepithelial lymphocytes (IEL) were studied in pigs in different age groups ranging from 1 day to 4.5 years. There were no major differences between the numbers of IEL in the jejunum and ileum. The postnatal increase of IEL largely depended on the breeding conditions: in germ-free animals there was a constant level, while in conventionally bred pigs the numbers increased more obviously than in specified pathogen-free (SPF) pigs. As the numbers of IEL can rise due to increased influx from other organs, decreased emigration, decreased apoptosis or local proliferation, the incorporation of the DNA precursor bromodeoxyuridine (BrdU) by IEL was studied after different labelling protocols. There were low but definite numbers of BrdU+ IEL 1 h after BrdU, indicating in-situ proliferation in conventional animals with a tendency to a higher index in the jejunum than the ileum. Repetitive labelling protocols for 14 days resulted in 12-20% BrdU+ IEL, which may be caused by local proliferation and immigration of lymphocytes produced in other lymphoid organs as documented for the pig. Future studies need to focus on the factors regulating local proliferation and the migration of IEL in different species.

Longitudinal study of lymphocyte subsets and major histocompatibility complex-class II expressing cells in mammary glands of sows

OBJECTIVE

To determine whether there is variation attributable to reproductive stage in lymphocyte subsets and major histocompatibility complex (MHC) class II expressing cells in mammary glands of sows.

ANIMALS

8 healthy primiparous crossbred sows that had been nursing piglets for 30 to 35 days.

PROCEDURE

Needle biopsy of the mammary gland was performed after parturition, at midlactation, and after weaning. Various lymphocyte subsets and MHC class II expressing cells were detected immunohistochemically, using monoclonal antibodies.

RESULTS

The number of CD8+ cells was significantly lower after parturition than after weaning but not significantly lower than at midlactation. The number of IgA-bearing cells was lower after parturition and after weaning than at midlactation. There were more B cells at midlactation than after weaning. There was no change over time in the number of CD4+ cells or MHC class II expressing cells. Immunohistochemically positive cells were detected only in interalveolar tissue.

CONCLUSIONS AND CLINICAL RELEVANCE

Certain lymphocyte subsets in mammary glands of sows are affected by reproductive stage. The data do not support the hypothesis that development of postparturient coliform mastitis may be the result of impaired mammary immune defenses at parturition.

A new isolation method for rat intraepithelial lymphocytes

Intraepithelial lymphocytes (IELs) play critical roles in gut immunity. In mice, gammadelta T cells are a large component of the IEL population. In the rat, gammadelta IELs are reportedly much less common, but technical issues suggest that previous analyses should be interpreted cautiously. The study of IELs in rats has been impeded by isolation procedures that are lengthy and complex, leading to small cell yields. For this reason, it is possible that rat IELs analyzed in previous studies have not been representative of the entire IEL compartment. We report a new method for the isolation of rat IELs that is based on the selective removal of intestinal epithelial cells under conditions that leave the basement membrane undisturbed. The method is rapid and requires neither enzymatic digestion, nor surgical removal of Peyer's patches, nor vigorous mechanical manipulation of the intestine. The yield of rat IELs using this method is 5- to 10-fold greater than that reported for other methods. Morphological and phenotypic analyses demonstrated that the purified cell population is comprised of IELs and is not contaminated with lamina propria or Peyer's patch lymphocytes. Phenotypic analysis revealed five major subsets of IELs based on differential cell surface expression of CD4, CD8, and alphabeta T cell receptor (TcR). Among the alphabetaTcR- cells was a population of gammadelta T cells present at levels not previously detected. The isolation of IEL sub-populations using this methodology should facilitate studies of the function of these cells in gut immunity.

Lymphocyte subpopulations in intrauterine growth retardation in women with or without previous pregnancies

OBJECTIVE

To evaluate lymphocyte subpopulations in pregnant women with intrauterine growth retardation (IUGR).

STUDY DESIGN

Forty-two normotensive and healthy women with singleton pregnancies and intrauterine growth retardation were studied in the third trimester of pregnancy and compared with 42 normal pregnant women. Peripheral blood lymphocytes were studied using murine monoclonal antibodies and flow cytometry.

RESULTS

B-lymphocytes in both total number (312.54 vs. 163.19 cells/mm3; P = 0.000003) and percentage (11.04% vs. 7.07%; P = 0.000002) were significantly increased in patients with IUGR in comparison to normal pregnant women. Significant correlations were found between birthweight and both total number and percentage of lymphocytes B. In primigravid women, we found that women with IUGR had a higher total lymphocyte count (2749.09 vs. 2130 cells/mm3; P = 0.006), higher T-lymphocyte count (2053.77 vs. 1676.40 cells/mm3; P = 0.02), higher B-lymphocyte count and percentage (309.13 vs. 145.36 cells/mm3; P = 0.000001) (11.45 vs. 6.81%); P = 0.00001), higher CD4 lymphocyte count and percentage (1342.68 vs. 972.22 cells/mm3, P = 0.001) (49.18 vs. 44.04%; P = 0.04), lower CD8-lymphocytes percentage (28.27 vs. 32.9%; P = 0.04), and higher CD4/CD ratio (1.83 vs. 1.46; P = 0.02) than the normal control group.

CONCLUSIONS

B-lymphocytes are increased in women with IUGR in comparison to women with normal pregnancies and there was a significant negative correlation between maternal B-lymphocytes and birthweight. With respect to T-lymphocytes, the immunological profile is different according to the presence or absence of a previous pregnancy. Fetal immunological rejection could be involved in the pathogenesis of IUGR in primigravid women, but in multigravid women there were no differences between women with IUGR and those with normal fetal growth.

Local immune responses to Chlamydia pneumoniae in the lungs of BALB/c mice during primary infection and reinfection

Cell-mediated immune (CMI) responses play a major role in protection as well as pathogenesis of many intracellular bacterial infections. In this study, we evaluated the infection kinetics and assessed histologically the lymphoid reactions and local, in vitro-restimulated CMI responses in lungs of BALB/c mice, during both primary infection and reinfection with Chlamydia pneumoniae. The primary challenge resulted in a self-restricted infection with elimination of culturable bacteria by day 27 after challenge. A mild lymphoid reaction characterized the pathology in the lungs. In vitro CMI responses consisted of a weak proliferative response and no secretion of gamma interferon (IFN-gamma). The number of lung-derived mononuclear cells increased substantially during the primary infection; the largest relative increase was observed in B cells (B220(+)). After reinfection, the number of lung-derived mononuclear cells increased further, and the response consisted mainly of T cells. The reinfection was characterized in vivo by significant protection from infection (fewer cultivable bacteria in the lungs for a shorter period of time) but increased local lymphoid reaction at the infection site. In vitro, as opposed to the response in naive mice, acquired immunity was characterized by a strongly Th1-biased (IFN-gamma) CMI response. These results suggest that repeated infections with C. pneumoniae may induce Th1-type responses with similar associated tissue reactions, as shown in C. trachomatis infection models.

Age-related changes in blood lymphocyte subsets of Saudi Arabian healthy children

The age-related changes in absolute and percentage values of lymphocyte subsets in the peripheral blood of healthy children of different ages (1 month to 13 years) were studied by flow cytometry. The absolute and percentage values for most lymphocyte subpopulations differed substantially with age. Comparisons among age groups from infants through adults revealed progressive declines in the absolute numbers of leukocytes, total lymphocytes, and T, B, and natural killer (NK) cells. The percentages of T cells increased with age. Within the T-lymphocyte population, the CD8(+) subset increased but the CD4(+) subset decreased, resulting in a declining CD4(+)/CD8(+) ratio. The percentage of B cells declined, but that of NK cells remained unchanged. The percentage of HLA-DR+ T cells increased over time, but their number changed inconsistently. Our findings confirm and extend earlier reports on age-related changes in lymphocyte subpopulations. These data should be useful in the interpretation of disease-related changes, as well as therapy-dependent alterations, in lymphocyte subsets in children of different age groups.

Subpopulations of lymphocytes in cattle naturally infected with papillomavirus

Subpopulations of blood lymphocytes (CD2, CD4, CD8, WC1 and IgM-mu chain) were evaluated in clinically manifested bovine papillomatosis. Significantly lower numbers of CD2 (44.7%), CD4 (22.8%) and a lower ratio of CD4/CD8 (1.5) were found in animals with tumours compared to a group of cattle free of papillomas (62.3%, 34%, and 2.3, respectively). On the other hand, significantly higher numbers of gamma/delta+ T lymphocytes (9.6%) and of lymphocytes expressing IgM molecules (35%) were observed in the group of tumour-bearing cattle than in the papilloma-free group (4.8% and 22.1%, respectively). The animals came from a region characterised by elevated concentrations of copper, zinc, arsenic, cadmium and lead in the soil and in the organs of animals. It is supposed that environmental factors predisposed the animals to the development of papillomas.

Aetiopathogenesis and treatment of idiopathic retroperitoneal fibrosis

Idiopathic retroperitoneal fibrosis (IRF) is a rare urological disease, for which many pathogenic theories have been proposed. The authors report a series of 13 cases of IRF in order to evaluate the clinical, diagnostic, laboratory, therapeutic and prognostic aspects. They also report a rare case (the ninth case reported in the literature) of multifocal fibrosclerosis. A possible genetic predisposition was studied by testing for the presence of immunophenotype HLA-B27; this test was positive in 44% of cases. A study of the immunological profile and lymphocyte populations revealed the typical features of chronic immune disease. Experience with medical and surgical treatment is reported, comparing various procedures: ureterolysis followed by application of a vascularized omental flap over the ureter (without subsequent corticosteroid therapy) gave the best results, with complete resolution of the symptoms and long-term successful alleviation of ureteric obstruction in 100% of patients, with a mean follow-up of 58 months.

Effects of the 120 days of head-down bed rest on cytokine secretion and its in vitro modulation by glucocorticoids

Antiorthostatic hypokinesia or head-down bed rest (HDBR), is a ground-based model system used to simulate some of the physioloical responses observed during space flight. Several studies involving humans and animals have demonstrated the effects of HDBR on different physioloical systems. HDBR produced a large thoracic fluid shift similar to that reported for space flight. Exposure to the combination of -6 degrees HDBR, emotional stress, and hypergravity led to an elevation of plasma histamine and serotinin and a dramatic decrease in the concentration of prostaglandins E, F2-alpha, and erthropoietin. These responses indicated the HDBR produces significant alterations in the neuroendocrine regulatory pathways. The proliferative response of immune cells in response to activators was significantly enhanced in antiorthostatically suspended mice; plasma corticosterone also was higher but splenic natural killer cell cytotoxicity remained unchanged after suspension. Bone-resporbing activity of supernatatants increased in mitogen-stimulated PBMC cultures of subjects exposed to -5 degrees HDBR for 370 days of HDBR. Proliferative activity of PBMCs had declined at the end of a 320-day HDBR and during the initial days of recovery, but the numbers of active rosette-forming T cells increased. These and other results suggest that most stress-induced immune changes are neuroendocrine modulated, and that corticosteroids play a significant role in this modulation. It is expected that HDBR-induced immune changes could result from similar mechanisms. In this study, we investigated the effect of 120 days of HDBR on Type-1 vs. Type-2 cytokine equilibrium in mitogen-activated PBMC culture, and how these reactions may correlate with changes in the neuroendocrine status.

Strategies for phenotyping apoptotic peripheral human lymphocytes comparing ISNT, annexin-V and 7-AAD cytofluorometric staining methods

The present article compares the reliability of four previously described cytofluorometric methods of apoptosis quantification for phenotyping apoptotic human lymphocytes. Each of these assays detects distinct cellular alterations of the apoptotic process. Alteration in plasma membrane integrity can be evaluated following 7-AAD incorporation and the translocation of phosphatidylserine from the inner to the outer layer of the plasma membrane can be detected through the FITC annexin V staining. DNA strand breaks in apoptotic nuclei can be evidenced by the ISNT assay and finally morphological modifications can be followed with FSC/SSC criteria. Comparative analysis of apoptosis in cultured PBMC from HIV-infected patients considering the FSC/SSC parameters, 7-AAD stainability and annexin V fixation revealed that the latter identifies early apoptotic cells, also characterized as 7-AAD(low) with a reduced FSC. Moreover these three methods proved to be reliable and gave statistically similar results when combined with cell surface detection of antigens such as CD4, CD8 and CD19 by specific mAbs. Importantly, the 7-AAD assay easily allowed the identification of debris/apoptotic bodies, which were still stained by anti-cell surface mAbs and might therefore significantly distort the apoptosis percentage in a given lymphocyte subset. In the present report we also point out that the ISNT assay is not appropriate for phenotyping apoptotic lymphocytes in PBMC. Indeed it can particularly underestimate the rate of apoptosis in the B-cell subset. This was found to be related to the apoptosis-associated decrease in cell surface antigen expression, which is dramatically exacerbated in the ISNT assay because of the stripper effect of ethanol used for cell permeabilization. Finally, we propose a three step analytical strategy to accurately phenotype apoptotic peripheral human lymphocytes. It includes two gating steps performed on FSC/SSC criteria and 7-AAD/FSC parameters to eliminate monocytes, granulocytes and debris-apoptotic bodies, the third step being the phenotyping step itself, performed in dual or triple staining experiments. Altogether these observations emphasize that it is essential to assess critically the ability of a cytofluorometric method to phenotype apoptotic cells in complex lymphoid populations and that inaccurate identification of cell subsets undergoing apoptosis can be readily overcome by gating properly the lymphoid population, and using assays which preserve cell surface structure.

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

Changes in the distribution of lymphocyte subpopulations in infants with perinatally acquired HIV infection are confounded by the rapid changes that are the result of normal maturation of the immune system. We describe the changes in seven lymphocyte phenotypes (CD3+ CD4+, CD3+ CD8+, CD8+ HLA- DR+, CD8+ CD38+, CD8+ CD57+, CD3-/ CD16+ 56+, and CD19+) over the first 2 years of life in 390 HIV-1 exposed but uninfected and 98 HIV-1-infected infants enrolled in the Women and Infants Transmission Study. The greatest changes in uninfected infants were declines in the CD3+ CD4+ lymphocytes and increases in CD8+ HLA- DR+ and CD19+ lymphocytes. All phenotypes were affected by HIV infection but the greatest changes were declines in the CD3+ CD4+ subset and increases in the CD3+ CD8+ and CD8+ HLA- DR+ subsets. Thus, this study provides reference data for the maturational changes in lymphocyte phenotypes in HIV-exposed but uninfected infants and describes the overall changes that occur with perinatally acquired HIV infection.

Quantification of cytokine gene expression in lamina propria lymphocytes of cattle following infection with Ostertagia ostertagi

Changes in cell surface markers and cytokine transcription were analyzed in lamina propria lymphocytes from control animals (noninfected calves) and calves after a single high but nonprotective primary infection with Ostertagia ostertagi. Flow cytometry of cells recovered from the lamina propria showed an increase in the percentages of IgM+, WC1+, and IL-2R+-bearing cells 10 days after infection; however, 2 mo after infection, cell staining was comparable to preinfection levels. Transcription levels of interleukins IL-2, IL-4, IL-10, and interferon (IFN)-gamma mRNA were measured using a competitive reverse transcription-polymerase chain reaction. Results indicated elevated levels of IL-4 and IFN-gamma in the infected animals at 10 days and at 60 days after infection. Transcription of IL-10 also increased; however, this change was not observed until 60 days postinfection.

Sequence analysis of rat integrin alpha E1 and alpha E2 subunits: tissue expression reveals phenotypic similarities between intraepithelial lymphocytes and dendritic cells in lymph

The integrin alpha OX-62 subunit is defined by the OX-62 monoclonal antibody that was raised against rat dendritic cells in lymph (veiled cells) and shows properties similar to those of human alpha E2 that is predominantly expressed on intraepithelial lymphocytes. To clone alpha OX-62, rat probes generated using primers specific for the human alpha E sequence were used to screen rat T cell cDNA libraries. cDNA clones encoding two similar but not identical alpha subunits that are closely related to but distinct from human alpha E were isolated. alpha E1 is predicted to be the rat homolog of mouse alpha M290 and alpha E2 corresponds to rat alpha OX-62. Immunofluorescence analysis revealed that mouse alpha E1 and rat alpha E2 are expressed in dendritic epidermal T cells in the skin, intraepithelial lymphocytes in the small intestine and in cells with a dendritic morphology present at sites where gamma delta T cells occur in lymphoid organs. Unexpectedly, alpha E2 is co-expressed with intracellular CD3-delta and a 33-kDa CD3 chain but not the T cell receptor in veiled cells. These findings suggest that veiled cells may be derived from a lymphoid precursor. Furthermore, veiled cells show phenotypic similarities to intraepithelial lymphocytes.

In vitro cell death of activated lymphocytes in Omenn's syndrome

Omenn's syndrome (OS) is characterized by erythrodermia, hepatosplenomegaly, lymphadenopathy, hypereosinophilia and elevated IgE levels associated with increased susceptibility to severe infections. Peripheral blood T cells, though usually present in normal number, show an activated phenotype (including an increased expression of CD95/Fas), a Th2 pattern of cytokine secretion and defective proliferative response to mitogens. In this report, we demonstrate that T cells from patients with OS undergo an excessive cell death in vitro resulting from two mechanisms. First, a substantial number of peripheral blood lymphocytes from OS patients die in unstimulated cultures (p = 0.009 vs. healthy controls). This spontaneous apoptosis is associated with reduced expression of bcl-2 gene product (p < 0.05) and can be prevented by addition of interleukin (IL)-2 (which also prevents down-modulation of bcl-2), while is independent from CD95 signaling. Second, lymphocytes from OS patients are highly susceptible to activation-induced cell death (AICD) induced with mitogens. This mechanism is largely independent from IL-2, while it can be significantly inhibited blocking CD95 with an IgG2b monoclonal antibody (mAb). The dependence of AICD from signals transduced via CD95 was confirmed showing that cross-linking CD95 with an IgM mAb induces a higher cell death in purified CD4+ CD45R0+ cells from OS patients than in controls (comparable for CD95 expression). Both mechanisms of cell death observed in this study result from lymphocyte hyperactivation occurring in vivo in these patients and may contribute to functional T cell defects of OS.

Regional phenotypic specialization of intraepithelial lymphocytes in the rat intestine does not depend on microbial colonization

Recent studies in mice and humans have provided evidence for regional specialization of gut intraepithelial lymphocytes (IEL). Here the authors report striking regional variability in the composition of IEL in rat small and large intestine. Two-colour immunofluorescence in situ analysis showed that the distribution of the CD3+ and CD3- IEL subpopulations varied, the proportion of T cells (CD3+) being higher in the ileum than in the jejunum and smallest in the colon. These differences were explained by variable numbers of the T-cell receptor (TCR)alpha/beta + (both CD8+ and CD4+) but not the TCR gamma/delta + subset. Moreover, the various IEL subpopulations showed distinct intraepithelial distribution patterns with CD4+ and CD8 alpha beta + T cells situated near the lamina propria, while CD3- IEL were located preferentially towards the adluminal part of the epithelium. Regional phenotypic variation did not depend on intestinal colonization because analogous results were obtained in germ-free rats. Conventionalization nevertheless caused a marked relative increase of small intestinal TCR alpha/beta + but not TCR gamma/delta + IEL. This increase was more sustained in the jejunum than ileum and eventually reduced the phenotypic IEL differences between the two sites. By contrast, microbial colonization of the colon induced only a transient increase of intraepithelial TCR alpha/beta + cells with no permanent phenotypic alterations. Both CD3+ and CD3- IEL contained subpopulations that expressed NKR-P1 independent of intestinal colonization. These results demonstrate phenotypic specialization of IEL at different levels of the gut and suggest that the indigenous flora is not essential to this end.

Short- and long-term beta-carotene supplementation do not influence T cell-mediated immunity in healthy elderly persons

Supplementation of healthy elderly persons with beta-carotene has been considered a way to enhance immune responses. In study 1 the short-term effect of beta-carotene (90 mg/d for 3 wk) on immunity was assessed in a randomized, double-blind, placebo-controlled longitudinal comparison of healthy elderly women. In study 2 the long-term effect of beta-carotene (50 mg every other day for 10-12 y) on immunity was assessed in a randomized, double-blind, placebo-controlled longitudinal comparison of men enrolled in the Physicians' Health Study. Subjects from both studies taking active supplements had significantly greater plasma beta-carotene concentrations than did subjects taking placebo. The pre- to postintervention change in delayed-type hypersensitivity skin test responses between beta-carotene and placebo groups in the short-term study was not significantly different, nor was the response between treatment groups in the long-term study. There were no significant effects due to beta-carotene supplementation on in vitro lymphocyte proliferation, production of interleukin 2, or production of prostaglandin E2 as a result of short- or long-term beta-carotene supplementation. In addition, there were no differences in the profiles of lymphocyte subsets [total T cells (CD3+), T helper cells (CD4+), T cytotoxic-suppressor cells (CD8+), and B cells (CD19+)] due to short- or long-term beta-carotene supplementation, nor were there differences in percentages of CD16+ natural killer cells or activated lymphocytes (cells expressing interleukin 2 transferrin receptor) due to long-term beta-carotene supplementation. Consistent results from these two trials show that beta-carotene supplementation did not have an enhancing or suppressive effect on T cell-mediated immunity of healthy elderly.

Regulation of human monocyte apoptosis by the CD14 molecule

Bacterial products such as LPS have been shown to activate monocytes and to increase CD14 expression, while anti-inflammatory cytokines, i.e., IL-4, down-regulate CD14. Furthermore, activation of monocytes increases survival, whereas deactivation evokes apoptosis (programmed cell death, PCD). This correlation among activation, CD14 expression, and the lifespan of the cells prompted us to investigate the role of CD14 in monocyte apoptosis. The effects of LPS and IL-4 on the expression of CD14, indicated by binding of Leu M3 Ab, and PCD of monocytes were studied simultaneously and in a kinetic fashion by multiparameter flow cytometry. Monocyte PCD was determined by binding of FITC-conjugated annexin V, which indicates apoptotic cell death in early stages, and was confirmed using well-established detection methods, i.e., DNA electrophoresis, electron microscopy, or colorimetric DNA staining. The present study shows that the LPS-induced increase in CD14 expression rescued monocytes from apoptosis, whereas IL-4 treatment first down-regulated CD14 expression and consecutively evoked apoptosis. CD14-/annexin V- monocytes were not apoptotic as confirmed by DNA electrophoresis, whereas CD14-/ annexin V+ monocytes showed clear apoptotic features. Kinetic studies ruled out that monocytes first bound annexin V and later lost the CD14 Ag. Other molecules, such as HLA-A, -B, and -C Ags, were not down-regulated during apoptosis. Enzymatic removal of membrane-bound CD14 by phosphatidylinositol-specific phospholipase C evoked PCD similarly to IL-4. These results suggest that regulation of CD14 receptor expression is an early effector mechanism mediating life or death of monocytes. Down-regulation or removal of the receptor triggers apoptosis, whereas up-regulation promotes survival.

Lymphocytic subpopulation changes after open and laparoscopic cholecystectomy: a prospective and comparative study on 38 patients

Up to now it has been unclear whether laparoscopic surgery has fewer immunosuppressive effects than traditional laparotomic procedures. In a series of 38 patients affected by symptomatic gallstone disease and operated on either by laparoscopy (group 1) or by traditional open surgery (group 2), we determined the postoperative changes in lymphocyte subpopulations up to postoperative day (POD) 30. We collected 15 ml of venous blood from all patients in both groups on the day before surgery and on POD 1, 7, 15, and 30. A control group (group 3) comprised 56 healthy volunteers; the control group was used only to ensure that baseline values were totally comparable with a normal population; only one blood sample was obtained from the subjects in group 3. Patients undergoing open cholecystectomy had a significant decrease in total lymphocyte count on POD 1. Basal levels of lymphocyte subpopulations did not differ significantly in the study and control groups. No differences were found in the preoperative lymphocyte cell counts in the two groups who underwent cholecystectomy. Pan-T cells (CD3) showed a statistically significant marked reduction throughout the observation period. The counts of helper (CD4), suppressor (CD8), and natural killer NK (CD16) T cells were reduced on POD 1; the NK cell (CD16) count remained low until POD 30, B lymphocytes showed no postoperative reduction. In patients who underwent laparoscopic cholecystectomy, a significant postoperative decrease in total lymphocyte count, and in CD3, CD4, and CD8 subpopulations was observed on day 1 only. There was no reduction in CD16 and CD19 subpopulations. A comparative statistical analysis of lymphocyte subpopulations in the two groups was carried out: In the open cholecystectomy group, compared with the laparoscopy group, CD3, CD4, CD8, and CD16 lymphocyte subpopulations showed marked reductions at different time points. In particular, statistically significant differences were found in CD3 levels from POD 1 through POD 30, in CD4 from day 1 through day 7, and in CD8 and CD16 only on day 1.

Isolation and phenotypic characterization of abomasal mucosal lymphocytes in the course of a primary Ostertagia ostertagi infection in calves

Isolation and characterization of surface marker phenotypes of abomasal intraepithelial (IEL), lamina propria (LPL) and abomasal lymph node lymphocytes (ABLN) from uninfected calves were conducted, and the dynamics of change in these populations during the course of a primary Ostertagia ostertagi infection were defined. To obtain viable IEL and LPL from the abomasal mucosa of cattle, a modified isolation method was developed. The phenotypic characterization of abomasal lymphocytes was accomplished by indirect immunofluorescence staining. In uninfected animals, numbers of T cells exceeded the number of immunoglobulin-bearing cells in IEL, LPL and ABLN. The predominant T cell type in IEL and LPL was CD8+ cells, while the CD4+ T cell predominated in ABLN. Levels of activated cells and T cell receptor-1 gamma delta T cells were higher in IEL and LPL compared to ABLN. Within 3 weeks of infection, the number of lymphocytes recovered from the abomasal lamina propira and the mass of the ABLN was dramatically increased when compared to uninfected animals. Laser flow cytometric analysis demonstrated increased levels of immunoglobulin-bearing cells, gamma delta T cells, and activated T cells in IEL, LPL and ABLN in the infected animals. The greatest changes in LPL and ABLN took place during the first days of infection, and these changes were apparent throughout the 28 days covered by the experiment.

Lymphocyte phenotyping in systemic sclerosis: a flow cytometry analysis of lymphocytes in bronchoalveolar lavage fluid

OBJECTIVE

Patients with scleroderma (systemic sclerosis [SSc]) frequently develop interstitial lung disease. The purpose of this work was to evaluate the cell profile in the bronchoalveolar lavage fluid (BALF) in patients suffering from a diffuse form of systemic sclerosis as compared with healthy controls.

STUDY DESIGN

Bronchoalveolar lavage was carried out in the right middle lobe of 25 untreated, nonsmoking patients with SSc and 12 healthy, nonsmoking volunteers. For the analysis of lymphocyte subsets, the following monoclonal antibodies were used: anti-CD3, anti-CD4, anti-CD8, anti-CD14, anti-CD16, anti-CD19, anti-CD25, anti-CD45, anti-CD56. Also, anti-HLA-DR and flow cytometry were used.

RESULTS

We found an increase in the total number of cells with an increase in the percentage of lymphocytes and neutrophils in BALF from patients when compared with controls (P < .05). The proportion of lymphocytes, cytotoxic/suppressor CD8+ and activated lymphocytes T CD25+ were higher in patients' BALF (P < .05). The CD4+/CD8+ ratio in BALF from subjects was significantly lower than in controls. These findings were characteristic of patients with early-stage disease.

CONCLUSION

Analysis of the BALF lymphocyte phenotype may be useful in the early detection of lung involvement in patients with SSc.

Differential immunological aberrations in patients with primary and secondary Sjögren's syndrome

The aim of the present study was to analyse possible differences in immunological features between patients with primary and secondary Sjögren's syndrome (SS). Ten patients with primary SS and 10 patients with secondary SS also suffering from rheumatoid arthritis, were identified according to established criteria for SS. Ten healthy, age-matched women served as controls. The authors analysed the phenotypic characteristics of lymphocytes in peripheral blood as well as in focal inflammatory infiltrates of minor salivary gland biopsies. Functional analyses of T lymphocytes were performed after stimulation with mitogens and antigen. B cell activity was determined at the single cell level by spontaneous and mitogen induced immunoglobulin production. Serum levels of IL-4, IL-6 and IFN-gamma were also analysed. Patients with primary SS displayed a significantly higher degree of salivary gland inflammation and reduced salivary flow than did patients with secondary SS. Decreased in vitro T cell responses to antigen and mitogens were evident in both patient groups. The CD4/CD8 ratios in both peripheral blood and salivary gland lesions were significantly lower in primary SS compared with secondary SS patients. Polyclonal B cell activation, measured as the frequency of spontaneous immunoglobulin producing cells, was most prominent in primary SS, whereas a diminished response to poke-weed mitogen (PWM), a T cell dependent B cell mitogen, was more pronounced in secondary SS. The results reveal certain immunological aberrations in the whole group of patients with SS. In addition, the authors demonstrated distinct differences in immune dysfunction between patients with primary and secondary SS, indicating that they may constitute separate entities.

Treatment of refractory Hodgkin's disease with an anti-CD16/CD30 bispecific antibody

Fifteen patients with refractory Hodgkin's disease were treated in a phase I/II trial with the natural killer (NK)-cell-activating bispecific monoclonal antibody HRS-3/A9, which is directed against the Fc(gamma)-receptor III (CD16 antigen) and the Hodgkin's-associated CD30 antigen, respectively. Median counts of NK cells and of all lymphocyte subsets were considerably decreased in the patients before therapy. HRS-3/A9 was administered 4 times every 3 to 4 days, starting with 1 mg/m2. The treatment was well tolerated, and the maximum tolerated dose was not reached at 64 mg/m2, the highest dose administered because of the limited amounts of HRS-3/A9 available. Side effects were rare and consisted of fever, pain in involved lymph nodes, and a maculopapulous rash. A total of 9 patients developed human antimouse Ig antibodies, and 4 patients developed an allergic reaction after attempted retreatment. A total of 1 complete and 1 partial remission (lasting 6 and 3 months, respectively) [corrected], 3 minor responses (1 to 11+ months), and 1 mixed response were achieved. There was no clear-cut dose-side effect or dose-response correlation. Our results encourage further clinical trials with this novel immunotherapeutic approach and emphasize the necessity to reduce the immunogenicity of the murine bispecific antibodies.