Hobit confers tissue-dependent programs to type 1 innate lymphoid cells

Identification of type 1 innate lymphoid cells (ILC1s) has been problematic. The transcription factor Hobit encoded by Zfp683 has been proposed as a major driver of ILC1 programs. Using Zfp683 reporter mice, we showed that correlation of Hobit expression with ILC1s is tissue- and context-dependent. In liver and intestinal mucosa, Zfp683 expression correlated well with ILC1s; in salivary glands, Zfp683 was coexpressed with the natural killer (NK) master transcription factors Eomes and TCF1 in a unique cell population, which we call ILC1-like NK cells; during viral infection, Zfp683 was induced in conventional NK cells of spleen and liver. The impact of Zfp683 deletion on ILC1s and NK cells was also multifaceted, including a marked decrease in granzyme- and interferon-gamma (IFNγ)-producing ILC1s in the liver, slightly fewer ILC1s and more Eomes+ TCF1+ ILC1-like NK cells in salivary glands, and only reduced production of granzyme B by ILC1 in the intestinal mucosa. NK cell-mediated control of viral infection was unaffected. We conclude that Hobit has two major impacts on ILC1s: It sustains liver ILC1 numbers, while promoting ILC1 functional maturation in other tissues by controlling TCF1, Eomes, and granzyme expression.

Duration of frequent or severe respiratory tract infection in adults before diagnosis of IgG subclass deficiency

Many adults with IgG subclass deficiency (IgGSD) experience long intervals of frequent/severe respiratory tract infection before IgGSD diagnosis, but reasons for delays in IgGSD diagnoses are incompletely understood. We performed a retrospective study of 300 white adults (ages ≥18 y) with IgGSD including frequency analyses of age at IgGSD diagnosis, duration of frequent/severe respiratory tract infection before IgGSD diagnosis, and age at onset of frequent/severe infection (calculated). We performed multivariable regressions on age at diagnosis, infection duration, and age at infection onset using these variables, as appropriate: sex; age at diagnosis; diabetes; autoimmune condition(s); atopy; allergy; corticosteroid use; body mass index; serum immunoglobulin isotype levels; blood lymphocyte subsets; three IgGSD-associated human leukocyte antigen-A and -B haplotypes; and referring physician specialties. Mean age at diagnosis was 50 ± 12 (standard deviation) y (median 50 y (range 19–79)). There were 247 women (82.3%). Mean infection duration at IgGSD diagnosis was 12 ± 13 y (median 7 y (range 1–66)). Mean age at infection onset was 38 ± 16 y (median 38 y (range 4, 76)). Age at infection onset was ≥18 y in 95.7% of subjects. Regressions on age at diagnosis and infection duration revealed no significant associations. Regression on age at infection onset revealed one positive association: age at diagnosis (p <0.0001). We conclude that the median duration of frequent/severe respiratory tract infection in adults before IgGSD diagnosis was 7 y. Older adults may be diagnosed to have IgGSD after longer intervals of infection than younger adults. Duration of frequent/severe respiratory tract infection before IgGSD diagnosis was not significantly associated with routine clinical and laboratory variables, including referring physician specialties.

Chronic HIV-1 Infection Alters the Cellular Distribution of FcγRIIIa and the Functional Consequence of the FcγRIIIa-F158V Variant

Chronic HIV-infection modulates the expression of Fc gamma receptors (FcγRs) on immune cells and their antibody-dependent effector function capability. Given the increasingly recognized importance of antibody-dependent cellular cytotoxicity (ADCC) in HIV-specific immunity, we investigated the cellular distribution of FcγRIIIa on cytotoxic lymphocytes—natural killer cells and CD8⁺ T cells—and the effect of the FcγRIIIa-F158V variant on ADCC capacity in HIV-infected individuals (n = 23) and healthy controls (n = 23). Study participants were matched for F158V genotypes, carried two copies of the FCGR3A gene and were negative for FcγRIIb expression on NK cells. The distribution of CD56^dimFcγRIIIa^bright and CD56^negFcγRIIIa^bright NK cell subsets, but not FcγRIIIa surface expression, differed significantly between HIV-1 negative and HIV-1 positive donors. NK cell-mediated ADCC responses negatively correlated with the proportion of the immunoregulatory CD56^brightFcγRIIIa^dim/neg cells and were lower in the HIV-1 positive group. Intriguingly, the FcγRIIIa-F158V variant differentially affected the NK-mediated ADCC responses for HIV-1 negative and HIV-1 positive donors. Healthy donors bearing at least one 158V allele had higher ADCC responses compared to those homozygous for the 158F allele (48.1 vs. 34.1%), whereas the opposite was observed for the HIV-infected group (26.4 vs. 34.6%), although not statistically significantly different. Furthermore, FcγRIIIa⁺CD8^bright and FcγRIIIa⁺CD8^dim T cell subsets were observed in both HIV-1 negative and HIV-1 positive donors, with median proportions that were significantly higher in HIV-1 positive donors compared to healthy controls (15.7 vs. 8.3%; P = 0.016 and 18.2 vs. 14.1%; P = 0.038, respectively). Using an HIV-1-specific GranToxiLux assay, we demonstrate that CD8⁺ T cells mediate ADCC through the delivery of granzyme B, which was overall lower compared to that of autologous NK cells. In conclusion, our findings demonstrate that in the presence of an HIV-1 infection, the cellular distribution of FcγRIIIa is altered and that the functional consequence of FcγRIIIa variant is affected. Importantly, it underscores the need to characterize FcγR expression, cellular distribution and functional consequences of FcγR genetic variants within a specific environment or disease state.

Group 2 innate lymphocytes at the interface between innate and adaptive immunity

Group 2 innate lymphoid cells (ILC2) are innate immune cells that respond rapidly to their environment through soluble inflammatory mediators and cell-to-cell interactions. As tissue-resident sentinels, ILC2 help orchestrate localized type 2 immune responses. These ILC2-driven type 2 responses are now recognized in diverse immune processes, different anatomical locations, and homeostatic or pathological settings. ILC2-derived cytokines and cell surface signaling molecules function as key regulators of innate and adaptive immunity. Conversely, ILC2 are governed by their environment. As such, ILC2 form an important nexus of the immune system and may present an attractive target for immune modulation in disease.

Characterization of pathogenesis of and immune response to Burkholderia pseudomallei K96243 using both inhalational and intraperitoneal infection models in BALB/c and C57BL/6 mice

Burkholderia pseudomallei, the etiologic agent of melioidosis, is a Gram negative bacterium designated as a Tier 1 threat. This bacterium is known to be endemic in Southeast Asia and Northern Australia and can infect humans and animals by several routes. Inhalational melioidosis has been associated with monsoonal rains in endemic areas and is also a significant concern in the biodefense community. There are currently no effective vaccines for B. pseudomallei and antibiotic treatment can be hampered by non-specific symptomology and also the high rate of naturally occurring antibiotic resistant strains. Well-characterized animal models will be essential when selecting novel medical countermeasures for evaluation prior to human clinical trials. Here, we further characterize differences between the responses of BALB/c and C57BL/6 mice when challenged with low doses of a low-passage and well-defined stock of B. pseudomallei K96243 via either intraperitoneal or aerosol routes of exposure. Before challenge, mice were implanted with a transponder to collect body temperature readings, and daily body weights were also recorded. Mice were euthanized on select days for pathological analyses and determination of the bacterial burden in selected tissues (blood, lungs, liver, and spleen). Additionally, spleen homogenate and sera samples were analyzed to better characterize the host immune response after infection with aerosolized bacteria. These clinical, pathological, and immunological data highlighted and confirmed important similarities and differences between these murine models and exposure routes.

Differential activation of CD57-defined natural killer cell subsets during recall responses to vaccine antigens

Natural killer (NK) cells contribute to the effector phase of vaccine-induced adaptive immune responses, secreting cytokines and releasing cytotoxic granules. The proportion of responding NK cells varies between individuals and by vaccine, suggesting that functionally discrete subsets of NK cells with different activation requirements may be involved. Here, we have used responses to individual components of the DTP vaccine [tetanus toxoid (TT), diphtheria toxoid (DT), whole cell inactivated pertussis] to characterize the NK cell subsets involved in interleukin-2-dependent recall responses. Culture with TT, DT or pertussis induced NK cell CD25 expression and interferon-γ production in previously vaccinated individuals. Responses were the most robust against whole cell pertussis, with responses to TT being particularly low. Functional analysis of discrete NK cell subsets revealed that transition from CD56bright to CD56dim correlated with increased responsiveness to CD16 cross-linking, whereas increasing CD57 expression correlated with a loss of responsiveness to cytokines. A higher frequency of CD56dim CD57− NK cells expressed CD25 and interferon-γ following stimulation with vaccine antigen compared with CD56dim CD57+ NK cells and made the largest overall contribution to this response. CD56dim CD57int NK cells represent an intermediate functional phenotype in response to vaccine-induced and receptor-mediated stimuli. These findings have implications for the ability of NK cells to contribute to the effector response after vaccination and for vaccine-induced immunity in older individuals.

Expansion of human NK-22 cells with IL-7, IL-2, and IL-1beta reveals intrinsic functional plasticity

Natural killer-22 (NK-22) cells are a human NK cell subset situated in mucosal-associated lymphoid tissues that specialize in IL-22 secretion in response to IL-23. Here we investigated the cytokine requirements for NK-22 cell expansion. IL-7 maintained the survival of NK-22 cells and IL-22 production in response to IL-23 but was insufficient to induce robust expansion. Proliferation of NK-22 cells was increased markedly by adding either IL-1beta or IL-2 to IL-7 and was even stronger in the presence of IL-1beta plus IL-2. In contrast to IL-7, continuous culture in IL-1beta and IL-2 modified NK-22 cytokine profiles. IL-1beta promoted constitutive IL-22 secretion rather than acute IL-22 production in response to IL-23 and induced IL-17 in some cells. IL-2 reduced secretion of IL-22 and IL-17, increasing production of IFN-gamma and leukemia inhibitory factor. Functional deviation toward IFN-gamma production also was induced by continuous culture in IL-23. These results demonstrate the functional plasticity of NK-22 cells, which may allow flexible responses to different pathogens. Finally, we found that NK-22 cells released the B-cell survival factor, B-cell activating factor belonging to the TNF family (BAFF), suggesting a potential role of NK-22 cells in promoting B-cell-mediated mucosal immunity.

A comparative method for processing immunological parameters: developing an "Immunogram"

BACKGROUND

The immune system is a network of numerous cells that communicate both directly and indirectly with each other. The system is very sensitive to antigenic stimuli, which are memorised, and is closely connected with the endocrine and nervous systems. Therefore, in order to study the immune system correctly, it must be considered in all its complexity by analysing its components with multiparametric tools that take its dynamic characteristic into account.

METHODS

We analysed lymphocyte subpopulations by using monoclonal antibodies with six different fluorochromes; the monoclonal panel employed included CD45, CD3, CD4, CD8, CD16, CD56, CD57, CD19, CD23, CD27, CD5, and HLA-DR. This panel has enabled us to measure many lymphocyte subsets in different states and with different functions: helper, suppressor, activated, effector, naïve, memory, and regulatory. A database was created to collect the values of immunological parameters of approximately 8,000 subjects who have undergone testing since 2000. When the distributions of the values for these parameters were compared with the medians of reference values published in the literature, we found that most of the values from the subjects included in the database were close to the medians in the literature. To process the data we used a comparative method that calculates the percentile rank of the values of a subject by comparing them with the values for others subjects of the same age.

RESULTS

From this data processing we obtained a set of percentile ranks that represent the positions of the various parameters with regard to the data for other age-matched subjects included in the database. These positions, relative to both the absolute values and percentages, are plotted in a graph. We have called the final plot, which can be likened to that subject's immunological fingerprint, an "Immunogram". In order to perform the necessary calculations automatically, we developed dedicated software (Immunogramma) which provides at least two different "pictures" for each subject: the first is based on a comparison of the individual's data with those from all age-related subjects, while the second provides a comparison with only age and disease-related subjects. In addition, we can superimpose two fingerprints from the same subject, calculated at different times, in order to produce a dynamic picture, for instance before and after treatment. Finally, with the aim of interpreting the clinical and diagnostic meaning of a set of positions for the values of the measured parameters, we can also search the database to determine whether it contains other subjects who have a similar pattern for some selected immune parameters.

CONCLUSIONS

This method helps to study and follow-up immune parameters over time. The software enables automation of the process and data sharing with other departments and laboratories, so the database can grow rapidly, thus expanding its informational capacity.

Flow cytometric analysis of lymphocyte subpopulations and TH1/TH2 balance in patients with polymyositis and dermatomyositis

OBJECTIVE

Polymyositis (PM) and dermatomyositis (DM) are idiopathic inflammatory myopathies; autoimmune mechanisms are thought to play an important role in their pathogenesis. We investigated the immunocytochemical characteristics and Th1/Th2 balance of peripheral blood lymphocytes in PM and DM using flow cytometry.

PATIENTS AND METHODS

Eight patients with PM and 13 with DM were enrolled in this study. Of these, 8 patients with DM were examined before and after clinical remission. No patients were receiving any treatment for PM or DM at enrollment. Ten healthy subjects were used as controls.

RESULTS

Patients with PM showed significant increases in CD3+CD4+HLA-DR+ (p<0.01) and CD19+CD23+ cells (p<0.05), and significant decreases in CD3+CD4+ (p<0.005) and CD4+CD45RO+ cells (p<0.05) compared with controls. Patients with DM showed significant increases in CD19+ (p<0.05) and CD19+CD23+ cells (p<0.05), and significant decreases in CD4+CD45RO+ cells (p<0.005) and the CD4+CD45RO+/CD4+CD45RA+ ratio (p<0.005) compared with controls. CD4+interferon (IFN)-gamma+ cells and the intracellular IFN-gamma/interleukin (IL)-4 ratio in CD4+ cells were significantly lower in patients with DM than in those with PM (p<0.05) or controls (p<0.0005 and p<0.001, respectively). The intracellular IFN-gamma/IL-4 ratio in CD4+ cells was significantly increased in DM after clinical remission compared with before (p<0.05).

CONCLUSION

Both B and helper T cells are activated in peripheral blood of active PM. Th2 cells predominate in peripheral blood of active DM, and the intracellular IFN-gamma/IL-4 ratio in CD4+ cells may be useful as a clinical marker indicating disease activity.

Influence of 4- and 6-color flow cytometers and acquisition/analysis softwares on the determination of lymphocyte subsets in HIV infection

BACKGROUND AND OBJECTIVES

Lymphocyte immunophenotyping provides valuable information for the diagnosis and monitoring of patients with cellular immunodeficiencies, such as HIV/AIDS. In this study, we have assessed the influence of 4-color and 6-color flow cytometers, and respective analytical softwares on the enumeration of lymphocytes in HIV infected individuals.

METHODS

The expression of various cell surface markers on lymphocytes was measured from the EDTA blood of 66 HIV infected patients on the FACSCalibur (4-color) and FACSCanto (6-color) flow cytometers. Percentage of lymphocytes expressing a particular cell surface marker was analyzed on FACSCalibur using the Cell Quest Pro software (v 5.2), while the analysis on FACSCanto was done using FACSCanto (v 1.0.3) and FACSDiva (v 4.1) softwares respectively.

RESULTS

The data shows significantly higher mean CD3 T-cell counts on FACSCalibur, Cell Quest Pro (1,864 +/- 1,044 cells/microl) as compared to FACSCanto (1,840 +/- 1,040 cells/microl) (P < 0.05). The CD4 T-cell counts were also higher on FACSCalibur, Cell Quest Pro (885 +/- 770 cells/microl), and FACSDiva (892 +/- 773 cells/microl) versus FACSCanto (867 +/- 767 cells/microl) (P < 0.05). FACSCalibur, Cell Quest Pro, and FACSDiva showed similar values except for CD8 T-lymphocytes where FACSDiva had significantly lower values (P < 0.05). The B-cell counts were unaffected when either of the instruments or softwares were used, while the natural killer (NK) cells (CD16 + 56 positive cells) showed similar trend like CD3 and CD4 counts with significant differences in the mean cell counts between FACSCalibur, Cell Quest Pro (240 +/- 165 cells/microl), and FACSDiva (238 +/- 163 cells/microl) versus FACSCanto with higher NK cell counts (260 +/- 176 cells/microl).

CONCLUSIONS

The enumeration of lymphocyte subsets was comparable between FACSCalibur, Cell Quest Pro, and FACSDiva, based analysis and it was significantly different than FACSCanto software based analysis. Our observations suggest that FACSDiva software should be preferred over the FACSCanto software for immunophenotyping on FACSCanto flow cytometer and the laboratories should report the instrument and software used for the specimen analysis while reporting immunophenotyping results.

Active vaccination in patients with common variable immunodeficiency (CVID)

Active vaccination of CVID patients with standard vaccines has rarely been studied in depth although some patients have been shown to develop transient vaccine-specific immunity. We addressed the question whether these patients can be identified by functional classification of their B cell subsets in vitro. Twenty-one CVID patients receiving regular IgG substitution were immunized with anti-peptide and anti-polysaccharide vaccines. Humoral vaccination responses were compared to the numbers of circulating memory B cells, CD21(low) B cells and the capacity to produce antibodies in vitro. Our findings allow four conclusions: (1) positive vaccination responses are not contradictory to the diagnosis of CVID; they occurred against polypeptide vaccines in 23% and against polysaccharide antigens in 18% of all vaccinations. (2) Class-switched antibody responses occur preferentially in patients of CVID group II. (3) A normal percentage of IgM memory B cells is necessary but not sufficient for a vaccination response to polysaccharide antigens. (4) Active vaccination in addition to IgG replacement therapy should be performed in patients of CVID type II - especially in case of vaccines for which passive protection cannot be guaranteed.

Common variable immunodeficiency in systemic lupus erythematosus

OBJECTIVE

The development of common variable immunodeficiency (CVID) or hypogammaglobulinemia in systemic lupus erythematosus (SLE) is rare. The purpose of this article is to provide a detailed review of lupus-associated CVID and to identify clinical characteristics and laboratory features in patients with SLE-associated CVID.

METHODS

We describe 2 patients with SLE and CVID and review the cases published in the English literature highlighting both the demographic and the clinical characteristics and the laboratory and therapeutic aspects of this disorder.

RESULTS

Detailed descriptions of 18 patients were available; 89% were females with a mean age at the onset of SLE of 23.8 years. In 50% of patients CVID developed within the first 5 years after the diagnosis of SLE. All patients had been treated with corticosteroids and 72% had also received immunosuppressive therapy. Sinopulmonary infections were the most frequent symptom. SLE disease activity decreased after the development of CVID in 67% of patients. Most patients (89%) were treated with gammaglobulin therapy. The most notable immunological feature was a reduced number or percentage of B-cells in 60% of patients.

CONCLUSIONS

CVID should be suspected in any SLE patient with recurrent sinopulmonary infections in the absence of SLE activity and/or immunosuppressive treatment.

Characterization of NKT-cell Hybridomas Expressing Invariant T-cell Antigen Receptors

Two natural killer T (NKT)-cell hybridomas were established by fusing sorted NKT cells with BW1100 thymoma cells. The first hybridoma line, 1B6, was CD4(+)8(-), whereas the second one, 2E10, was CD4(low)8(-). Initial characterizations revealed that both cell lines expressed an invariant T cell antigen receptor, which could be readily detected with alpha-galactosylceramide-loaded CD1d : Ig fusion protein (alpha-GalCer/CD1d). Sequence analyses of the alpha and beta chains of the T cell receptor V genes revealed that 1B6 and 2E10 cells expressed V alpha 14J alpha 18/V beta 8.2D beta 2J beta 2.7 and V alpha 14J alpha 18/V beta 8.1D beta 1J beta 1.1, respectively. When these hybridoma cells were stimulated with immobilized anti-CD3 monoclonal antibodies, alpha-GalCer/CD1d, or alpha-GalCer in the presence of antigen-presenting cells, they produced IL-4 and IFN-gamma. The expression levels of CD69, CD154, and CD178 were concomitantly up-regulated on both hybridomas upon stimulation. Because it is difficult to isolate a sufficient number of NKT cells, these hybridomas should provide useful platforms to study a variety of functions of NKT cells.

Prenatally Diagnosable Differences in the Cellular Immunity of Fetuses with Down’s and Edwards’ Syndrome

INTRODUCTION

Lymphocyte subpopulations are identified by the uniform CD classification (Cluster of Differentiation) and can be accurately differentiated with monoclonal antibodies using the method of flow cytometry. With the aid of cordocentesis it is possible to perform studies on the status and development of cellular immunity as early as in the second trimester of pregnancy.

OBJECTIVE

To compare lymphocyte subpopulations present in fetuses with chromosomal abnormalities (Down's syndrome (DS), Edwards' syndrome (ES)) and fetuses with normal karyotype.

STUDY DESIGN

Prospective observational study.

METHODS

We examined a total of 61 pregnant women with an average age of 31.5 years (20- 46 years).

RESULTS

In fetuses with DS we found a significant decrease in B lymphocytes (CD19),a decrease in the subpopulations of multi-reactive B-cells (CD5(+)CD19(+), B-CLL),and a decrease in the index of CD4/CD8 and class II HLA-DR. In contrast, the representation of NK cells expressing /CD3-CD (16 + 56)+/ was greatly increased. In ES we found a decrease in T lymphocytes (CD3), a decrease in T-helper lymphocytes (monocytes CD4), a decreased index of CD4/CD8 and a greater representation of NK cells /CD3-CD (16 + 56)+/.

CONCLUSION

We determined the normal values of lymphocyte subpopulations in physiological fetuses. We demonstrated that the immunological defect of the affected fetuses is already present antenatally, and can be reliably diagnosed in the second trimester of pregnancy.

CD27 Dissects Mature NK Cells into Two Subsets with Distinct Responsiveness and Migratory Capacity

Lineage differentiation and the formation of heterogeneous mature subsets are crucial for immune cells to maintain a breadth of responsiveness to pathogens while controlling reactivity to self. In this study, we report that CD27 is a key marker of the NK cell lineage, dissecting the mature Mac-1high NK cell pool into two functionally distinct subsets. The CD27low NK cell subset possesses a higher threshold to stimulation and appears to be tightly regulated by the expression of NK cell inhibitory receptors. Comparatively, the CD27high NK cell subset displays a greater effector function, exhibits a distinct tissue distribution and responsiveness to chemokines, and interacts productively with dendritic cells. Importantly, we have verified that CD27high and CD27low subsets with distinct cell surface phenotypes also exist in human peripheral blood. These findings clearly reclassify mature NK cells into two distinct subsets and begin to discern their specific role in immune responses.

NK cells in autoimmune disease

The role of NK cells in autoimmunity has not been extensively studied. Speaking for a disease-promoting role for NK cells in autoimmune diseases are recent results suggesting that IFN-gamma production by NK cells may help adaptive immune responses diverge in the direction of a Th1 response. NK cells may also be involved in direct killing of tissue cells, which could lead to acceleration of autoimmunity. However, NK cells have also been shown to protect from some autoimmune diseases. A possible reason for this discrepancy may lie in the capacity of NK cells also to produce Th2 cytokines, which could downregulate the Th1 responses that are common in autoimmune disorders. Thus there is at present no coherent view on the role of NK cells in autoimmunity, and more work is needed to clarify why NK cells in some cases aggravate disease and in some cases protect from disease.

Immunophenotypical Characterization of Lymphocyte Subpopulations of the Uterus of Non-pregnant and Pregnant Goats

The increased susceptibility during pregnancy to certain pathogens that cause abortions may be related to changes in the distribution and phenotype of lymphocyte subpopulations in the uterus. Histological, electron microscopic and immunocytochemical techniques were used in this study to examine whether such variations occur in different stages of the reproductive cycle of goats. The study of non-pregnant goats showed that most uterine lymphocytes were T cells and displayed both an intraepithelial and stromal distribution. CD8+ T lymphocytes were more numerous than CD4+ T lymphocytes. In the endometrial epithelium two lymphocyte subpopulations were observed: non-granulated CD2+ CD8+ T lymphocytes and granulated CD2+ CD8- T lymphocytes. During gestation, no lymphocytes were observed in the placentomal area, while a decreased number of T lymphocyte subpopulations were found in the inter-placentomal area. In the inter-caruncular epithelium, non-granulated CD2+ CD8+ T lymphocytes disappeared, whereas the granulated CD2+ CD8- T lymphocyte subpopulations increased their number and changed their morphology.

Lymphocyte changes in peripheral blood, spleen, and liver in DMBA-induced squamous cell carcinoma of mouse cheek skin

The peripheral blood, spleen, and liver lymphocyte subsets of mice with experimental cheek skin carcinoma were determined. The carcinoma was induced by the topical application of 2% (w/v) 9,10-dimethyl-1,2-benzanthracene (DMBA) to cheek skin twice a week for 12 weeks, and it was examined macroscopically and histopathologically. The composition of lymphocyte subsets (T cells, B cells, CD4+ single-positive [SP] T cells, and CD8+SP T cells) in peripheral blood, spleen, and liver was determined by flow cytometry at 3-week intervals for up to 24 weeks. Spleens and livers were assessed by determining their content of natural killer (NK)T cells. The results showed histopathological progression of the skin lesions from papilloma to squamous cell carcinoma at week 12. Body weight was significantly reduced from weeks 15 to 24, and spleen weight was significantly increased at weeks 21 and 24, but liver weight was not significantly different from the control. The lymphocyte subset composition of peripheral blood showed significant elevation of T cells at weeks 6 and 9, followed by reduced levels at weeks 21 and 24, with significant reduction of B cells at weeks 6 and 9, followed by elevation at weeks 21 and 24. CD4+SP T-cell content was elevated at weeks 6, 9, and 12, and reduced at weeks 21 and 24. CD8+SP T-cell content was significantly reduced at weeks 6, 9, and 12, and elevated at weeks 21 and 24. The composition of the lymphocyte subsets in the spleen was similar to their composition in peripheral blood. The composition of both T and B cells in the liver was significantly different from that in the corresponding control group, but no significant differences were found in either CD4+SP or CD8+SP T cells. These findings revealed that the DMBA-induced cheek skin carcinoma in mice affected not only the lymphocyte subsets in peripheral blood, but the cells in the spleen and liver as well.

Unstable angina is accompanied by immune cells dysfunction

Inflammatory process has been found to play an important role in the pathogenesis of coronary heart disease (CHD) and in the prognosis of coronary artery disease (CAD) patients. The purpose of our study was to investigate some cellular immune parameters during the development of angina in the stable and the unstable stage. We have investigated the proliferative capacity of lymphocytes isolated from the peripheral blood of stable and unstable angina patients. The proliferative capacity of peripheral lymphocytes was evaluated with the radioisotopic method of tritiated thymidine incorporation. The peripheral lymphocytes present an enhanced basal proliferation of cells and lectine induced stimulation (P = 0.02/ P = 0.001), especially in the unstable angina patients, correlated with an increased population of CD4+ peripheral T-lymphocytes (P = 0.0006). The cellular immune parameters announce the development of an acute coronary syndrome. The unstable angina presents alteration of some cellular immune parameters that indicate an inflammatory syndrome associated with an increased risk of CHD, having also a prediction value for the plaque instability.

NK cells and the tumour microenvironment: implications for NK-cell function and anti-tumour activity

Although it is clear that natural killer (NK) cells have the ability to recognize and kill tumour cells in vitro, their potential as a highly effective treatment for tumours has not yet been realized in the clinical setting. Following activation, endogenous and adoptively transferred NK cells can be found in tumours. However, not all tumours are equally well-infiltrated, and many of the infiltrating cells do not make target-cell contact but rather reside in the tumour stroma. New insights into the migration of NK cells, their activation status and production of matrix-degrading proteases might help to overcome this localization defect, with implications for the treatment of human cancer.

Interleukin-18 levels in the plasma of psoriatic patients correlate with the extent of skin lesions and the PASI score

Interleukin-18 is a cytokine with a possible role in the pathogenesis of psoriasis. We examined subpopulations of peripheral blood lymphocytes and their expression of activation markers and correlated this with plasma levels of IL-18 and clinical disease severity in patients with psoriasis. We included 12 patients with psoriasis who had a PASI score from 15 to 48 and compared them to controls. IL-18 plasma concentrations were determined with an enzyme-linked immunosorbent assay. We observed a significant correlation between the IL-18 levels and the area of skin affected with psoriasis and the PASI score. We also observed an increase in NK cells and memory helper CD45RO + /CD4+cells.

Involvement of inducible costimulator-B7 homologous protein costimulatory pathway in murine lupus nephritis

Inducible costimulator (ICOS)-B7 homologous protein (B7h) is a new member of the CD28-B7 family of costimulatory molecules that regulates T cell-dependent humoral immune responses. In this study, we examined the involvement of this costimulatory pathway in the development and progression of lupus in NZB/W F(1) mice. Expression of ICOS on T cells was enhanced with disease progression, whereas B7h expression on B cells was down-regulated. Administration of anti-B7h mAb before the onset of renal disease significantly delayed the onset of proteinuria and prolonged survival. Blockade of B7h effectively inhibited all subclasses of IgG autoantibody production and accumulation of both Th1 and Th2 cells. Hypercellularity and deposition of IgG and C3 in glomeruli were significantly reduced. B7h blockade after the onset of proteinuria prevented the disease progression and improved the renal pathology. Our results demonstrated the involvement of the ICOS-B7h costimulatory pathway in the pathogenesis of lupus nephritis, and the blockade of this pathway may be beneficial for the treatment of human systemic lupus erythematosus.

Regression of metastatic osteosarcoma following non-myeloablative stem cell transplantation. A case report

report the evidence of regression of multiple metastases following non-myeloablative stem cell transplantation (NST) from an HLA-identical sibling in a case of relapsed fibroblastic osteosarcoma. The course of NST was well tolerated. Full donor chimerism was achieved on day +150 both for CD15+ and CD3+ cells. Complete remission was achieved on day +116. On day +210 the patient relapsed with a scapular metastasis that was unresponsive to four doses of donor lymphocyte infusion (DLIs). To our knowledge, this is the first reported case showing the achievement of complete remission following NST in an osteosarcoma patient.

Role of murine intestinal intraepithelial lymphocytes and lamina propria lymphocytes against primary and challenge infections with Cryptosporidium parvum

To investigate the role of intestinal lamina propria lymphocytes (LPL) and intraepithelial lymphocytes (IEL) in controlling Cryptosporidium parvum infection, changes in their phenotypes and functional properties were studied after induction of primary and challenge infections in immunocompetent mice. As shown by oocyst-shedding patterns, the challenge-infected group recovered more rapidly from infection than did the primary-infected group. In LPL, proportions of activated CD4+, CD25+, IgG1+, IgA+, and CD4+/IFN-gamma+ cells increased significantly in the primary-infected group compared with controls. In the challenge-infected group, proportions of these cells decreased. The antigen-specific IgA level was elevated significantly among LPL of both primary- and challenge-infected groups. Among IEL, proportions of activated CD8+, T cell receptor (TCR) gammadelta+, and CD8+/TCR gammadelta+ cells increased significantly in the challenge-infected group compared with controls and the primary-infected group; their cytotoxicity also was enhanced. However, the proportion of IEL expressing Th1 cytokines was lower than that among LPL in both infected groups. The results suggest that LPL play a more important role in protection against a primary infection with C. parvum, through the production of IFN-gamma and IgA, whereas IEL are more involved in protection against a challenge infection, through enhanced cytotoxicity.

Changes in lymphocyte subsets after cardiac surgery in children

Children undergoing cardiopulmonary bypass (CPB) operations have an increased risk of developing severe infections. Impairment of the immune system may contribute to the development of sequelae such as capillary leaks, pulmonary dysfunction and auto-immune reactions. The objective of this study was to investigate the impact of cardiac surgery with CPB on the immune system of infants and young children. We conducted a prospective study to investigate the changes in circulating lymphocyte subpopulations in a sample of 21 consecutive infants and young children undergoing cardiac surgery for congenital heart disease. The following statistically significant ( P<0.05) results were obtained: leucocyte counts rose 6 h after surgery due to the increase in neutrophils. Absolute T-cell number and absolute T-helper cell number decreased within 24 h after CPB. The proportion of T-cells expressing the T-cell receptor gammadelta as well as natural killer cells increased during CPB. In contrast, the proportion of T-cells expressing activation markers (CD25, CD45R0) decreased within 24 h after CPB, as did the number of cells expressing adhesion molecules (CD11b and ICAM).

CONCLUSION

during cardiac surgery with cardiopulmonary bypass, absolute natural killer cell counts increase while T-cells decrease, presumably due to an extravasation or adhesion of activated T-cells. The relevance of this finding regarding the risk of infection is discussed.

Heterogeneity of humoral immune abnormalities in children with Nijmegen breakage syndrome: an 8-year follow-up study in a single centre

During an 8-year period of observation, defects of immune responses were characterized and monitored in 40 of 50 Polish children with Nijmegen breakage syndrome referred to the Children's Memorial Health Institute in Warsaw. The following parameters were determined at diagnosis: (1) concentrations of serum IgM, IgG, IgA; (2) concentrations of IgG subclasses; and (3) lymphocyte subpopulations. In addition, naturally acquired specific antibodies against Streptococcus pneumoniae were determined in 20 patients with a history of recurrent respiratory infections. During follow-up, total serum immunoglobulins and IgG subclasses were monitored systematically in 17 patients who did not receive immunomodulatory therapy. Moreover, anti-HBs antibody response was measured after vaccination of 20 children against HBV. We found that the immune deficiency in NBS is profound, highly variable, with a tendency to progress over time. Systematic monitoring of the humoral response, despite good clinical condition, is essential for early medical intervention.

The strength of the OVA-induced airway inflammation in rats is strain dependent

To examine the influence of genetics on the OVA-induced allergic inflammatory response in lungs we compared rats that are genetically Th2-predisposed (Brown Norway, inbred) or not genetically predisposed (Sprague Dawley, outbred). Rats were sensitized with ovalbumin (OVA) and challenged four weeks later with OVA aerosol. Eighteen hours after challenge, lung tissue was studied for evaluation of numbers of eosinophils, neutrophils, macrophages and mast cells, as well as for expression of P-selectin, E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on endothelial cells. From a separate portion of the pulmonary tissue, leucocytes were isolated to analyse numbers of IFNgamma and IL-4 producing cells (ELISPOT assay) and frequencies of T-cell subsets and B cells. We found increased numbers of eosinophils and neutrophils in the lung, an increased number of IL-4 producing cells in lung cell isolates and increased levels of serum (OVA- specific)-IgE in both rat strains. In addition, expression of E-selectin and ICAM-1 was up regulated in both rat strains whereas expression of VCAM-1 was only up regulated in the BN rat. Although the 'allergic' Th2 response to OVA was detectable in both rat strains, it was more pronounced in the BN rat than in the SD rat. However, the SD rat, which is not predisposed to respond in either a Th2 or Th1-like way, appeared capable of mounting an allergic response to OVA. This suggests that other factors than genetic contribute to allergic disease.

DiGeorge sequence with hypogammaglobulinemia: a case report

The most common immunodeficiency in DiGeorge sequence patients is defects in T-cell production due to insufficient thymic tissue. However, because T-lymphocytes are important in regulating antibody responses, DiGeorge sequence is no longer regarded as a pure deficiency of cellular immunity but also a form of variable-combined immunodeficiency. Here we presented a 4-month-old male infant with characteristic facial dysmorphism, thymus dysplasia, tetralogy of Fallot, and documented deletion of chromosome 22q11.2 who had decrease B-lymphocyte numbers and hypogammaglobulinemia. The mitogen responses of T-lymphocytes function were normal with adequate number of CD4+ lymphocytes. This case report highlights the importance of evaluating not only the cellular but also the humoral immune function in patients with DiGeorge sequence.

Immunohistochemical analysis of lymphocyte subpopulations in cyclosporin A-induced gingival overgrowth

BACKGROUND

Cyclosporin A (CsA) is an immunosuppressive agent that is known to induce gingival overgrowth (GO). Pharmacological, genetic, immunologic, and inflammatory factors seem to be involved in the complex pathogenesis of drug-induced GO. Lymphocyte subpopulations in human gingival connective tissue have been implicated in the pathogenesis of inflammatory periodontal diseases. One purpose of this study was to quantify CD4, CD8-, CD57-, and epithelial membrane antigen (EMA)-positive cells in the gingiva of renal transplant recipients treated with CsA, and compare them to findings in healthy controls. A second aim was to correlate cell numbers with clinical findings.

METHODS

The study included 19 kidney recipients who were taking CsA and had significant GO (CsAGO+), 13 recipients who were taking CsA but showed no GO (CsAGO-), and 14 systemically healthy individuals with gingivitis (C). Sections from gingival biopsies were incubated with monoclonal antibodies for CD4, CD8, EMA, and CD57, and then analyzed using the avidin-biotin complex method. In each specimen, the mononuclear cell types were quantified and their distribution was evaluated in 3 separate tissue zones: S = subepithelial connective tissue beneath the sulcular epithelium; O = subepithelial connective tissue beneath the oral epithelium; and M = middle connective tissue.

RESULTS

There were no significant differences among the groups with respect to the numbers of CD4+ and CD8+ cells in each of the 3 zones (P >0.05). In zone S, the CsAGO+ group had significantly more EMA-positive cells than either the C or CsAGO- groups (P <0.05). There were significant differences among the groups regarding numbers of CD57+ (natural killer) cells in zone M, with the lowest cell numbers in the CsAGO+ patients (P<0.05).

CONCLUSIONS

The results showed that low numbers of natural killer cells are important in the expression of plaque-induced inflammatory changes in CsA-associated GO. It appears that these cells may influence the drug's ability to induce proliferative activity.

Effect of minocycline and doxycycline on IgE responses

BACKGROUND

We have recently found that the tetracycline minocycline suppresses inflammatory responses in serum immunoglobulin (Ig)E-positive asthmatic patients, and that IgE levels can decrease in these patients. The mechanism by which minocycline suppresses these responses is unknown.

OBJECTIVE

We have now investigated the ability of the tetracyclines, minocycline and doxycycline, to regulate IgE responses of peripheral blood mononuclear cells (PBMC) obtained from serum IgE-positive asthmatic patients.

METHODS

The distributions of CD3+, CD4+, CD8+, and CD19+ lymphocytes in peripheral blood of serum IgE-positive asthmatic patients and IgE-negative nonasthmatic controls, and cytokine-specific mRNA expression by their PBMC were determined by flow cytometry (reverse transcriptase-polymerase chain reaction). Serum Ig levels also were determined (nephelometry, fluoroenzymeimmunoassay, enzyme-linked immunoadsorbent assay; n = 7/group). PBMC (1.5 x 10(6)/mL) were cultured with anti-CD40 monoclonal antibody and recombinant human interleukin-4 in the presence/absence of minocycline or doxycycline (0.1 to 10 microg/mL), and IgE levels in supernatants determined on days 0, 3, and 10 (enzyme-linked immunoadsorbent assay).

RESULTS

Asthmatic and nonasthmatic subjects had similar numbers of blood CD4+ T cells (779/mm3 +/- 73 and 766 +/- 115, respectively) and CD19+ B-cells (239/mm3 +/- 35 and 379 +/- 95, respectively); however, CD8+ T cell numbers were decreased in asthmatic compared with nonasthmatic subjects (378/mm3 +/- 66 and 568 +/- 53, respectively; P = 0.045). High IgE levels were detected in supernatants of asthmatic PBMC on day 10 (28 ng/mL +/- 12), whereas control IgE levels did not change (<2.5 ng/mL). When either minocycline or doxycycline was included in culture, IgE production by asthmatic PBMC was strongly suppressed in dose-dependent fashion on day 10 (>80% with 10 microg/mL); control IgE did not change (<2.5 ng/mL).

CONCLUSIONS

The results are consistent with the idea that the therapeutic benefits obtained by asthmatic patients from minocycline may, in part, result from IgE suppression.

Kinetics of changes in lymphocyte sub-populations in mouse lungs after intrapulmonary infection with M. bovis (Bacillus Calmette-Guerin) and identity of cells responsible for IFNgamma responses

Gamma interferon (IFNgamma) plays a key role in host defense against pulmonary mycobacterial infections. A variety of lymphocyte subsets may participate in producing pulmonary IFNgamma responses, but their relative contributions after mycobacterial infection have not been clearly elucidated. To address this question, C57Bl/6 female mice were infected by intrapulmonary instillation of 2.5 x 104 BCG (Mycobacterium bovis Bacillus Calmette-Guerin). Lymphocyte populations in lung interstitium were examined at different time points after the infection. BCG load in lungs peaked between 4 and 6 weeks post-infection and declined to very low levels by the 12th week of infection. Recovery of lung interstitial lymphocytes doubled by 4-6 weeks after infection and declined thereafter. Flow cytometric analysis of the lung-derived lymphocytes revealed that about 5% of the these cells made IFNgamma in control mice, and this baseline IFNgamma production involved T (CD3+NK1.1-), NK (CD3-NK1.1+) and NKT (CD3+NK1.1+) cells. As the BCG lung infection peaked, the total number of CD3+ T cells in the lungs increased threefold at 5-6 weeks post-infection. There was a marked increase (sixfold) in the number of T cells secreting IFNgamma 5-6 weeks post-infection. Some increase was also noted in the NKT cells making IFNgamma, but the numbers of NK cells making IFNgamma in BCG-infected lungs remained unaltered. Our results suggest that whereas NK and NKT cells contribute to baseline IFNgamma secretion in control lungs, expansion in the IFNgamma-producing T-cell population was essentially responsible for the augmented response seen in lungs of BCG-infected mice.

Reference values of lymphocyte subsets in the normal healthy adult Kuwaiti Arab population

Fluorescent monoclonal antibody labelling followed by a lysed whole blood method and flow cytometry was used to determine the lymphocyte subpopulations in 127 (64 males and 63 females) normal healthy individuals in the adult (age 18-59 years) Kuwaiti population. Relative percentages and absolute values of CD2+, CD3+, CD19+, CD4+, CD8+, HLADR+, CD56+, CD45RO+, and CD45RA+ cells were determined. The reference ranges were CD2+, 73-92% (0.95-2.99 x 10(9) per l), CD3+, 64-85% (0.83-2.71 x 10(9) per l), CD19+, 6-22% (0.05-0.61 x 10(9) per l), CD4+, 34-54% (0.45-1.65 x 10(9) per l), CD8+, 20-42% (0.29-1.17 x 10(9) per l), HLADR+, 4-23% (0.02-0.62 x 10(9) per l), CD56+, 4-22% (0.06-0.58 x 10(9) per l), CD45RO+, 16-53% (0.26-1.42 x 10(9) per l) and CD45RA+, 35-72% (0.34-2.05 x 10(9) per l). The mean CD4/CD8 ratio was 1.50+/-0.35. CD3+ cells were positively correlated to both CD4+ and CD8+ cells (P<0.001), and CD4+ cells showed a significant positive correlation with CD8+ cells (P<0.001).

Lymphocyte phenotype analysis and chromosome aberration frequency of workers occupationally exposed to styrene, benzene, polycyclic aromatic hydrocarbons or mixed solvents

The aim of our study was to investigate the immunotoxicity of benzene, styrene and polycyclic aromatic hydrocarbon exposure, to establish the correlation between immunological and genotoxicological parameters, and to assess the possible effect of confounding factors such as age and smoking. The immune status of the donors was characterized by measuring the surface antigens of peripheral lymphocytes. The studied antigens were the following: CD3, CD4, CD8, CD14, CD19, CD25, CD38, CD45, CD45RO, CD54, CD56, CD62L, CD71 and HLA-DR. In our studies, we compared the immunological and genotoxicological parameters (chromosome aberration, sister chromatid exchange frequency, unscheduled DNA synthesis) of the different groups with healthy controls. Analysis revealed changes in the expression of surface antigens on peripheral lymphocytes in correlation with exposure. Confounding factors, such as smoking, increased the proportion of CD4 positive T lymphocytes and influenced the surface expression of several antigens. In our investigation the occurrence of chromosome aberrations negatively correlated with CD25 (IL-2R) expression in both CD4 and CD8 positive T cells. The presented data suggest that solvents such as benzene, styrene and PAHs activate peripheral lymphocytes, and cause changes in the incidence of CD25+/CD4+ T lymphocytes that may represent a distinct subset of immune-regulatory T cells.

Applications of enzymatic amplification staining in immunophenotyping hematopoietic cells

Immunofluorescent staining of mammalian cells has provided a reliable approach for detection of specific antigen expression in situ. An advantage of fluorescent markers has been their applicability to automated, high-throughput cellular analysis by flow cytometry. Flow cytometry has thus become an integral component of clinical laboratory diagnostics, particularly in the areas of immunology and hematology. One of the major drawbacks of traditional immunofluorescent staining, even with flow cytometric detection, has been the difficulty in detecting low abundance cellular antigens, some of which may have clinical and scientific significance. To address these problems, staining techniques have recently been developed to increase the sensitivity of cellular antigen detection by flow cytometry. In this review we will describe a few of these techniques and focus on enzymatic amplification staining as a means to generate a highly augmented antigen-specific signal. We will also discuss practical applications of enzymatic amplification for immunostaining of clinical specimens.

Cellular kinetics of an allergic-type response in a sheep mammary gland model of inflammation

BACKGROUND

Tissue recruitment of eosinophils and activated lymphocytes is a characteristic feature of allergic reactions. However, little is known about the involvement of specific adhesion molecules in the traffic of leucocytes during the allergic response.

OBJECTIVE

To use a sheep mammary infusion model to characterize the kinetics of cell recruitment and expression of cellular adhesion molecules and activation markers on eosinophils and lymphocytes involved in an allergic-type response.

METHODS

Mature non-lactating ewes were primed and challenged by direct infusion of the mammary glands with nematode larvae. Using a non-invasive method of saline infusion and 'milking' of the glands, large numbers of inflammatory cells were repeatedly sampled over 10 to 96 h following their migration into the mammary gland lumen, and analyzed by 2-colour flow cytometry.

RESULTS

Leucocyte recruitment into the mammary lumen was characterized by two separate phases involving an acute neutrophilic response at 10 h post-challenge, followed by a dramatic reduction in neutrophils and appearance of eosinophils and activated lymphocytes. From 48 h post-challenge, eosinophils were predominant and represented 40 to 65% of leucocytes in the mammary lavage (MAL). Increases in activated CD4+ T cells and gammadelta+ T cells were also observed at this time-point. The kinetics of expression of cell surface molecules on eosinophils and lymphocytes in blood and MAL were compared during the course of the allergic-type reaction. Adhesion molecule expression on lymphocytes was modulated following allergen challenge and an activation of MAL vs. blood lymphocytes was seen during the later stages of the allergic response. Eosinophil expression of VLA-4 and l-selectin was down-regulated compared with blood at all time-points examined. There were high levels of expression of CD11b and CD44 on eosinophils during the early compared to the late-phase of the allergic reaction.

CONCLUSION

These results indicate the existence of two separate mechanisms of eosinophil recruitment during the allergic inflammatory response.

The nonclassical major histocompatibility complex molecule Qa-2 protects tumor cells from NK cell- and lymphokine-activated killer cell-mediated cytolysis

The cytotoxic activity of NK cells is regulated by class I MHC proteins. Although much has been learned about NK recognition of class I autologous targets, the mechanisms of NK self-tolerance are poorly understood. To examine the role of a nonpolymorphic, ubiquitously expressed class Ib Ag, Q9, we expressed it on class I-deficient and NK-sensitive B78H1 melanoma. Presence of this Qa-2 family member on tumor cells partially protected targets from lysis by bulk lymphokine-activated killer (LAK) cells. H-2K(b)-expressing B78H1 targets also reduced LAK cell activity, while H-2D(b) offered no protection. Importantly, blocking with F(ab')(2) specific for Q9 or removal of this GPI-attached molecule by phospholipase C cleavage restored killing to the level of vector-transfected cells. Experiments with LAK cells derived from H2(b) SCID and B6 mice established that NK1.1(+)TCR(-) NK and NK1.1(+)TCR(+) LAK cells were the prevalent cytolytic populations inhibitable by Q9. Treatment of mice with poly(I:C) also resulted in generation of Q9-regulated splenic cytotoxicity. LAK cells from different mouse strains responded to Q9, suggesting that the protective effect of this molecule is not detectably influenced by Ly49 polymorphisms or the presence/absence of Q9 in NK-harboring hosts. We propose that Q9 expressed on melanoma cells serves as a ligand for yet unidentified NK inhibitory receptor(s) expressed on NK1.1(+) NK/T cells.

Flow-cytometric analysis of lymphocyte subsets and mCD14 expression in patients with various periodontitis categories

BACKGROUND

Membrane-bound CD14 (mCD14) is expressed mainly on circulating monocytes and tissue macrophages. It is one of the receptors, which act at the recognition of lipopolysaccharides by host cells. Periodontopathic bacteria result in activation of cellular and humoral immune responses.

AIM

The aim of the present study was to analyze the peripheral blood mCD14 concentrations as well as cell surface markers of lymphocyte subsets in periodontitis patients of various categories.

MATERIALS AND METHODS

Peripheral blood samples were obtained from 22 early onset periodontitis (EOP), 10 adult periodontitis (AP) patients and 13 systemically and periodontally healthy control subjects. Three-color flow cytometry and a panel of relevant monoclonal antibodies were used to determine the percent expression of various cell surface markers on peripheral blood mononuclear cells (PBMCs). The results were tested statistically by one-way variance analysis and Newman Keuls test.

RESULTS

No significant difference was observed between the study groups with regard to the relative counts of B-cells, T-cells, T-helper, T-cytotoxic/suppressor, activated T-cells and natural killer cells. EOP patients expressed significantly lower level of interleukin-2 receptor (IL-2R) when compared with AP patients (6.08% and 19.3% respectively) (p<0.05). The level of mCD14 in EOP patients (7.18%) was lower than that of AP patients (9.3%) and the control subjects (9.2%), but the differences were not statistically significant.

CONCLUSIONS

The low level of IL-2R in the EOP group may be interpreted as an insufficient responsiveness to the periodontopathogens, which may be ultimately related with the more severe tissue destruction. Though not significant, the reduced expression of mCD14 in EOP group may also be related with the immune system deficiencies in these patients.

An extensive monoclonal antibody panel for the phenotyping of leukocyte subsets in the common marmoset and the cotton-top tamarin

New World monkeys are valuable animal models to study human diseases. To determine the phenotype of cells involved in immune responses, we used flow cytometry to screen a large panel of anti-human monoclonal antibodies (mAb) for cross-reactivity with cells of the common marmoset and the cotton-top tamarin. Certain antigens (e.g., CD2, CD8, CD20) are well conserved. However, CD10, CD23, and CD33 showed a clear discrepancy in their reaction patterns in both species, indicating that significant differences on the epitope level occurred during evolution. Epstein-Barr virus-transformed B-cell lines were shown to be a valuable tool for screening B-cell-specific reagents. In some cases, fluorescein isothiocyanate (FITC) and phycoerythrin (PE) modification of mAbs had a negative effect on the binding capacity, which stressed the importance of choosing the right label. Despite the fact that some CD antigens were not detected, adequate numbers of cross-reactive mAbs were identified to perform extensive studies on immunological functions in both the common marmoset and the cotton-top tamarin.

Use of human CD3 monoclonal antibody for accurate CD4+ and CD8+ lymphocyte determinations in macaques: phenotypic characterization of the CD3- CD8+ cell subset

Macaque monkeys are frequently used in models for studies of infectious diseases, immunity, transplantation and vaccine development. Such use is largely due to the conservation of functionally important cell surface molecules and the phylogenetic proximity of their immune systems to that of humans. Some monoclonal antibodies (mAb) raised against human leukocyte antigens can be utilized in the monkey. Until recently, many primate centers have utilized the CD2 monoclonal antibody to enumerate T lymphocytes. We have evaluated the anti-human CD3 mAb in macaques and sooty mangabeys. Using this monoclonal antibody, pigtailed macaques were found to have a much higher proportion of CD2+ CD3- CD8+ cells as compared with rhesus macaques and sooty mangabeys. Such cells comprised approximately one-half of all CD8+ cells in the pigtailed macaque, but only one-quarter of CD8+ cells in the rhesus, and one-fifth in the sooty mangabey. Use of the CD2 monoclonal antibody as the T-cell marker resulted in underestimating CD4/CD8 ratios compared with using the CD3 mAb in pigtailed macaques. Phenotypic characterization of this subset of CD3- CD8+ cells indicated that they are CD16+, CD45RA+, CD11b+, CD69+ and CD28-. This would indicate that these cells represent an activated natural killer cell subset.

Dysregulated expression of pre-Talpha reveals the opposite effects of pre-TCR at successive stages of T cell development

The pre-TCR complex (TCRbeta-pre-TCRalpha chain (pTalpha)), first expressed in a fraction of CD8(-)4(-)CD44(-)25(+) (DN3) cells, is believed to facilitate or enable an efficient transition from the CD8(-)4(-) double-negative (DN) to the CD8(+)4(+) double-positive (DP) developmental stage. Subsequent to pre-TCR expression, DN3 thymocytes receive survival, proliferation, and differentiation signals, although it is still unclear which of these outcomes are directly induced by the pre-TCR. To address this issue, we generated mice bearing a range of pTalpha transgene copy number under the transcriptional control of the p56(lck) proximal promoter. All lines exhibited increased DN3 cycling, accelerated DN3/4 transition, and improved DN4 survival. However, the high copy number lines also showed a selective reduction in thymic cellularity due to increased apoptosis of DP thymocytes, which could be reversed by the ectopic expression of Bcl-2. Our results suggest that transgenic pTalpha likely caused apoptosis of DP thymocytes due to competitive decrease in surface TCRalphabeta formation. These results highlight the critical importance of precise temporal and stoichiometric regulation of pre-TCR and TCR component expression.

Liposome-encapsulated tumor necrosis factor-alpha enhances the effects of radiation against human colon tumor xenografts

Recent reports have shown that tumor necrosis factor-alpha (TNF-alpha) can augment the effects of radiation against certain tumor types. However, the high concentrations of intravenous infusion of TNF-alpha needed to cause tumor regression can induce many systemic side effects. The aims of this study were to determine if TNF-alpha encapsulated in sterically stabilized (Stealth, ALZA Corporation, Mountain View, CA), PEGylated liposomes (SL) augments the antitumor effects of radiation and to compare its efficacy and possible toxicity with free TNF-alpha in the LS174T human colon tumor xenograft model. Nude mice were injected subcutaneously (s.c.) with LS174T cells and treated intravenously (i.v.) with Stealth-liposomal TNF-alpha (SL-TNF-alpha) with and without radiation or TNF-alpha with or without radiation when tumor size was approximately 200 mm(3). In phase 1, a significant decrease (p = 0.047) in tumor growth was observed with radiation at day 21 but not with SL-TNF-alpha or free TNF-alpha alone. By the end of phase 1 (day 27) with continued treatments, the SL-TNF-alpha plus radiation group had significantly smaller tumors (p = 0.044) than those in the free TNF-alpha plus radiation group. In phase 2, where a similar tumor growth reduction pattern was observed, the addition of TNF-alpha to radiation, either as free protein or within SL, increased lymphocyte activation and natural killer (NK) cell numbers in both blood and spleen. The effect was generally more pronounced with SL-TNF-alpha. Systemic toxicity, based on hematologic analyses and body weight, was absent or minimal. Collectively, the data show that pretreatment with SL-TNF-alpha can enhance more effectively, and possibly more safely, the effects of radiation against human colon tumor xenografts than can free TNF-alpha and that the increased antitumor action may involve upregulation of lymphocytes.

The biology of human natural killer-cell subsets

Human natural killer (NK) cells comprise approximately 15% of all circulating lymphocytes. Owing to their early production of cytokines and chemokines, and ability to lyse target cells without prior sensitization, NK cells are crucial components of the innate immune system. Human NK cells can be divided into two subsets based on their cell-surface density of CD56--CD56(bright) and CD56(dim)--each with distinct phenotypic properties. Now, there is ample evidence to suggest that these NK-cell subsets have unique functional attributes and, therefore, distinct roles in the human immune response. The CD56(dim) NK-cell subset is more naturally cytotoxic and expresses higher levels of Ig-like NK receptors and FCgamma receptor III (CD16) than the CD56(bright) NK-cell subset. By contrast, the CD56(bright) subset has the capacity to produce abundant cytokines following activation of monocytes, but has low natural cytotoxicity and is CD16(dim) or CD16(-). In addition, we will discuss other cell-surface receptors expressed differentially by human NK-cell subsets and the distinct functional properties of these subsets.

Final steps of natural killer cell maturation: a model for type 1-type 2 differentiation?

Analysis of cytokine and differentiation antigen expression in human natural killer (NK) cells revealed that interleukin 13 (IL-13) and interferon gamma (IFN-gamma) are produced at sequential stages during irreversible IL-12-induced differentiation. In human NK cell clones, polyclonal CD3-CD161+CD56- cells and peripheral lymphocytes, IL-4 induced the proliferation of both IL-13+ NK and T cells, whereas IL-12 allowed a proliferation-independent accumulation of IFN-gamma+ cells. These data disproved the NK1-NK2 hypothesis and challenge the current T helper 1 (TH1)-TH2 paradigm. We propose that the cytokine environment regulates a type 2-->0-->1 developmental progression, with IL-12 needed for terminal differentiation and IL-4 delaying this process, rather than a type 1 versus type 2 decision of a type 0 cell.

Infiltration of canonical Vgamma4/Vdelta1 gammadelta T cells in an adriamycin-induced progressive renal failure model

We have previously reported an infiltration of renal interstitial gammadelta T cells in Adriamycin-induced progressive glomerulosclerosis in the rat kidney. The TCR repertoire and sequences used by these gammadelta T cells have now been studied. Two injections of Adriamycin 14 days apart caused segmental glomerulosclerosis, massive interstitial infiltration of mononuclear cells, and end-stage renal failure. Flow cytometry of lymphocyte subpopulations with Abs to CD3, the gammadelta TCR, and the alphabeta TCR showed that gammadelta T cells as a proportion of CD3(+) cells were increased in Adriamycin-treated kidneys (8.5 +/- 5.4%), but not in lymph nodes (1.3 +/- 0.4%). A semiquantitative score of glomerular damage (r = 0.65; p < 0.01) and creatinine (r = 0.62; p < 0.01) correlated significantly with the presence of gammadelta T cells. TCR Vgamma repertoire analysis by RT-PCR and Southern blotting showed that Vgamma2 was the dominant subfamily in lymph nodes, whereas Vgamma4 became the predominant subfamily in advanced stages of the rat Adriamycin-treated kidney. Sequencing of the Vgamma4-Jgamma junctional region showed an invariant sequence. The amino acid sequence of the junctional region of the Vgamma4 TCR was the same as the reported mouse canonical Vgamma4 TCR sequence. Analysis of the kidney Vdelta repertoire showed dominant expression of Vdelta1, and sequencing again revealed the selective expression of a canonical Vdelta1 gene. Semiquantitative RT-PCR for cytokine gene expression showed that gammadelta T cells from the kidneys expressed TGF-beta, but not IL-4, IL-10, or IFN-gamma. These results suggest that the predominant gammadelta T cells in the Adriamycin kidney use an invariant Vgamma4/Vdelta1 receptor.

Simultaneous analysis of surface marker expression and cell cycle progression in human peripheral blood mononuclear cells

One method for examining cell cycle kinetics by flow cytometry uses continuous DNA labeling with bromodeoxyuridine (BrdU), a thymidine analogue. Upon incorporation into DNA, BrdU causes stoichiometric quenching of the DNA fluorochrome Hoechst 33258. After counterstaining with a secondary DNA fluorochrome (e.g., ethidium bromide), the analyst can distinguish cells in different phases of the cell cycle over a number of mitotic cycles with flow cytometry. In this report, we describe a modification of the flow cytometric BrdU-Hoechst assay that allows combined analysis of cell proliferation and immunophenotyping at the single cell level. To demonstrate an application of this method, human peripheral blood mononuclear cells were stimulated with tetanus toxoid or interleukin-2 for up to 6 days in the presence of BrdU, harvested, and immunostained for the cell surface markers CD3, CD4, CD8, CD14, CD19, and the cytokine receptor, CCR5. We used four-color flow cytometry analyses to simultaneously measure cell proliferation and surface marker expression, for the purpose of immunophenotyping and identifying specific cell subsets responding to antigen stimulation. Our successful application of this method suggests that it may be used to study immune responses at the molecular and cellular level and to identify mechanisms of immune system modulation.

Specific and nonspecific NK cell activation during virus infection

The natural killer (NK) cell activation receptor Ly49H is required for resistance to murine cytomegalovirus (MCMV). We show here that NK cell proliferation and production of interferon-gamma (IFN-gamma) was not dependent on Ly49H expression during early MCMV infection. During a later phase of infection, however, Ly49H+ NK cells selectively proliferated and this expansion was blocked by anti-Ly49H administration. With vaccinia virus infection, neither the early nor late phase of NK cell proliferation was selective for Ly49H+ NK cells. These findings indicated that Ly49H+ NK cells were specifically activated by MCMV and that MCMV infection was characterized by nonspecific and specific phases of NK cell activation in vivo.

Role of cyclin kinase inhibitor p21 in systemic autoimmunity

The cyclin kinase inhibitor protein p21 affects multiple processes relevant to the immune system, including cell cycle progression, replicative senescence, hemopoietic stem cell quiescence, and apoptosis. Therefore, malfunction of this protein may be a contributor to the pathogenesis of systemic autoimmunity. Here, we report that mixed background p21-deficient 129/Sv x C57BL/6 mice showed increased in vitro and in vivo T cell cycling and activation, moderate hypergammaglobulinemia and, at low penetrance, anti-chromatin autoantibodies. Homeostatic anti-self MHC/peptide ligand-induced proliferation of p21-deficient T cells was also enhanced. However, lymphoid organ enlargement was very mild, presumably due to increased apoptosis of the rapidly dividing cells. Moreover, the older p21-deficient mice had kidney pathology representing a similar, but slightly more advanced, state than that seen in the control mice. The timing and severity of the above serologic, cellular, and histologic manifestations in p21-deficient mice were unaffected by gender. Thus, p21 deficiency significantly enhances T cell activation and homeostatic proliferation, and can induce mild autoimmune manifestations at a low incidence without gender bias, but does not in itself generate the full spectrum of lupus-like disease.