AB0115 MONOCYTE CHEMOATTRACTANT PROTEIN-1 IN PATIENTS WITH PSORIATIC SPONDYLOARTHRITIS CORRELATES WITH COMPONENTS OF PATIENT FUNCTIONAL STATUS

Background

Activated monocytes represent the main source of pro-inflammatory chemokine, Monocyte Chemoattractant Protein-1 (MCP-1) in psoriatic skin lesions and synovial tissue during active psoriatic arthritis (PsA) (1). Osteoclast precursors binds MCP-1, implying the involvement of MCP-1 in the pathogenesis of bone erosion (2). MCP-1 is present in the plasma of patients with psoriasis at higher levels than in healthy subjects (3).

Objectives

The aim of this study was to determine the relationship between serum MCP-1 concentration and disease activity in PsA patients.

Methods

We enrolled 52 patients with PsA in the study and assessed Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Disease Activity in Psoriatic Arthritis (DAPSA), Bath Ankylosing Spondylitis Disease Functional index (BASFI), and the spread of psoriasis using Body Surface Area (BSA) method. In the serum, C-reactive protein (CRP) was measured using immunoturbidimetric assay and MCP-1 concentration using ELISA. Relationship between two parameters was analyzed applying Spearman correlation and p<0.05 was considered significant.

Results

Serum MCP-1 concentration did not correlate with the BSA, the DAPSA, CRP, the number of tender joints from 68 evaluated, the number of swollen joints from 66 evaluated, the patient’s assessment of the intensity of pain and overall disease activity during the last week. The concentration of MCP-1 did not correlate with the fatigue, the intensity of pain in axial and peripheral joint structures, the sensitivity to touch, the duration of morning stiffness, BASDAI and BASFI.

MCP-1 statistically significantly correlated with the score for getting up from a sitting position without the help of hands, for getting up from a floor without the help, for standing up without supporting for 10 minutes and for performing physically demanding activities (Figure 1).

Figure 1.

Correlation of serum MCP-1 concentration and BASFI components in patients with PsA.

Conclusion

Serum MCP-1 concentrations in PsA patients seem to reflect some components of patient functional status.

References

[1]Furst DE, Louie JS. Targeting inflammatory pathways in axial spondyloarthritis. Arthritis Res Ther. 2019;21(1):135.

[2]Yao Y, Cai X., Ren F., Ye Y. Et al.Macrophage-Osteoclast Axis in Osteoimmunity and Osteo-Related Diseases.Front Immunol. 2021; 12: 664871.

[3]Woo Y R et al. The Risk of Systemic Disease in Those with Psoriasis and Psoriatic Arthritis: From Mechanisms to Clinic. Int J Mol 2020 (21)7041.

Acknowledgements

University of Rijeka supported the resarch by the grants Uni-ri-biomed-18-110 and Uni-ri-biomed-18-160.

Disclosure of Interests

None declared

POS0407 OXYSTEROL 7-KETOCHOLESTEROL CAN RE-PROGRAM SYNOVIAL TISSUE MACROPHAGES AND SUPPORT M1 POLARIZATION

Background

Oxidized low-density lipoprotein (oxLDL) particles support low-grade inflammation and have been found in synovial fluid from osteoarthritis (OA) joints [1]. Their component is 7-ketocholesterol (7-KC), which arises as the result of the oxidation of cholesterol [1]. 7-KC acts proinflammatory and it binds to Toll-like receptor (TLR) 4 expressed on macrophages [1]. Activation of TLR4 stimulates the classical macrophage maturation program, resulting in a specific phenotype of inducible nitric oxide synthase positive (iNOS+) and macrophage (M) 1 function, which produce and secrete proinflammatory chemokines and cytokines [2]. M2 macrophages are associated with wound healing by the production of arginase-1 [2,3]. Synovial macrophages are of critical importance in the symptomatology and structural progression of OA since M1 polarized macrophages accumulate in human OA synovial tissue during exacerbation [3]. However, it is not known whether 7-KC can re-program synovial tissue macrophages and support M1 polarization.

Objectives

We analyzed the influence of 7-KC on the polarization of CD68+ macrophages in the suspension of synovial mononuclear cells (SMCs) in respect to lipopolysaccharide (LPS), as M1 inducer.

Methods

Mature synovial tissue samples were obtained during alloarthroplasty of the knee (N = 56). Paraffin embedded tissue sections were labelled by double immunofluorescence using a combination of antibodies directed toward CD68 and iNOS, arginase-1, CCL2 or CCL22. Suspension of SMCs was prepared by enzymatic digestion of tissue samples using collagenase IV and gradient density centrifugation. We analyzed intracellular (iNOS, arginase-1, CCL2, and CCL22) and surface (CD91, mannose receptor, HLA-DR, CD80, CD86 and decoy D6) antigens expression in CD68+ cells in the suspension of freshly isolated or 18 hour-cultured SMCs with 7-KC (25 μM), LPS (10 ng/ml), their combination or in the medium only.

Results

iNOS and CCL2 were more frequently labelled in lymphocyte clusters, while arginase-1 and CCL22 were labelled in synovial lining CD68+ cells. Phenotype of CD68+ cells did not change significantly after the 18 hour- culture in the medium only, except the decrease of mannose receptor and CD91, when compared with freshly isolated cells. 7-KC increased the percentage of CD86 expressing CD68+ cells, whereas decreased surface expression of CD91 and chemokine decoy D6, like in the culture with LPS, when compared with cells cultured in the medium only. 7-KC decreased the frequency of arginase-1+/CD68+ cells in the suspension and did not change iNOS+ in CD68+ cells, thus increasing the ratio of iNOS+/arginase-1+ in CD68+ subset. 7-KC was unable to increase CCL2 like LPS in comparison with cells cultured in the medium only. Neither 7-KC nor LPS affected CCL22 expression in the CD68+ subset.

Conclusion

These data provide a new perspective in understanding the polarization of macrophages toward the M1 phenotype mediated with oxysterol 7-KC in vitro.

References

[1]Niki E. Biomarkers of lipid peroxidation in clinical material. Biochim Biophys Acta. 2014;1840(2):809-17.

[2]Fernandes TL, Gomoll AH, Lattermann C, Hernandez AJ, Bueno DF, Amano MT. Macrophage: A Potential Target on Cartilage Regeneration. Front Immunol. 2020;11:111.

[3]Zhang H, Cai D, Bai X. Macrophages regulate the progression of osteoarthritis. Osteoarthritis Cartilage. 2020;28(5):555-561.

Acknowledgements

The University of Rijeka supported the research by the grants No. Uni-ri-biomed-18-110 and No. Uni-ri-biomed-18-160.

Disclosure of Interests

None declared.

AB0075 SYNOVIAL TISSUE MACROPHAGES ARE DOMINANTLY ALTERNATIVELY ACTIVATED IN PATIENTS WITH MATURE OSTEOARTHRITIS

Background:

Macrophages are abundant inflammatory cell type in the synovial membrane of knee osteoarthritis (OA) (1). Their quantity is associated with radiographic severity of knee OA and joint symptoms (2), while their functions are set in response to micro-environmental signals (3). Classically activated macrophages M1 support T helper 1 (Th1) driven pro-inflammatory reactions, while alternatively activated macrophages M2 strengthen Th2 inflammatory processes (3).

Objectives:

To investigate activation status of synovial tissue macrophages in patients with mature OA in terms of M1 / M2 polarization.

Methods:

Synovial tissue samples (6) with abundant lymphocyte infiltration were obtained during aloarthroplasty. Double immunofluorescence labeling was performed on paraffin-embedded synovial tissue sections using primary rabbit anti-macrophage CD68 mAb in combination with mouse anti-human antibodies directed toward CD3, arginase-1, TNF-alpha and IL-15. CD206 and CD163 were single labelled.

Results:

CD68+ macrophages mostly co-expressed arginase-1 (4/6 samples), indicating their M2 orientation. Macrophages were placed in lining synovial tissue and nearby tissue-resident CD3+ cells. M2 markers CD206 and CD163 were found in the area of macrophage interaction with T cells. CD68+ cells co-expressing TNF-alpha or IL-15 M1 markers were in minority in these synovial tissues. Lymphocyte infiltration was less abundant in remaining (2/6) synovial tissue samples.

Conclusion:

Mature synovial tissue macrophages, equipped dominantly with arginase-1 are M2 oriented and might support Th2 immune response in surrounding T cells.

References:

[1]Grieshaber-Bouyer R, Kämmerer T, Rosshirt N, Nees TA, Koniezke P, Tripel E, Schiltenwolf M, Kirsch J, Hagmann S, Moradi B. Divergent Mononuclear Cell Participation and Cytokine Release Profiles Define Hip and Knee Osteoarthritis. J Clin Med. 2019;8(10):piiE1631.

[2]Haraden CA, Huebner JL, Hsueh MF, Li YJ, Kraus VB. Synovial fluid biomarkers associated with osteoarthritis severity reflect macrophage and neutrophil related inflammation. Arthritis Res Ther. 2019;21(1):146.

[3]Barros MH, Hauck F, Dreyer JH, Kempkes B, Niedobitek G. Macrophage polarisation: an immunohistochemical approach for identifying M1 and M2 macrophages. PLoS One. 2013;8(11):e80908.

Acknowledgments:

University of Rijeka supported the research by the grants No. Uni-ri-biomed-18-110 and No. Uni-ri-biomed-18-160.

Disclosure of Interests:

None declared

Granulysin Expression in Lymphocytes that Populate the Peripheral Blood and the Myocardium after an Acute Coronary Event

We aimed to analyse granulysin (GNLY)-mediated cytotoxicity in the peripheral blood of patients with non-ST-segment elevation myocardial infarction (NSTEMI) treated with anti-ischaemic drug therapy. Thirty-nine NSTEMI patients with a median age of 70 years and 28 age-matched healthy subjects were enrolled in this study. On day 7 after MI, the number of GNLY(+) lymphocytes in the peripheral blood increased approximately six-fold of that in the healthy subjects, measured by flow cytometry. On day 14, the number of GNLY(+) cells significantly decreased in T, NKT, and both CD56(+dim) and CD56(+bright) NK subsets. GNLY(+) CD3(+) and GNLY(+) CD56(+) cells infiltrated central zone of myocardial infarction (MI). In persons who died in the first week after MI, GNLY(+) cells were found within accumulation of apoptotic leucocytes and reached the apoptotic cardiomyocytes in border MI zones probably due to the influence of interleukin-15 in peri-necrotic cardiomyocytes, as it is was shown by immunohistology. By day 28, the percentage of GNLY(+) lymphocytes in peripheral blood returned to the levels similar to that of the healthy subjects. Anti-GNLY mAb decreased apoptosis of K562 targets using peripheral blood NK cells from days 7 and 28 after MI, while in assays using cells from days 1 and 21, both anti-GNLY and anti-perforin mAbs were required to significantly decrease apoptosis. Using NK cells from day 14, K562 apoptosis was nearly absent. In conclusion, it seems that GNLY(+) lymphocytes, probably attracted by IL-15, not only participate partially in myocardial cell apoptosis, but also hasten resolution of cardiac leucocyte infiltration in patients with NSTEMI.

Obesity dilemma in the global burden of cardiovascular diseases

AIM

Obesity is a well-known risk factor in the cardiovascular disease continuum. However, its clinical effects are multimodal, perplexed and non-unanimously understood. Our aim was to assess the prevalence and effects of obesity on the cardiometabolic risk factors and systolic function of left ventricle ejection fraction (LVEF) in patients scheduled for cardiovascular rehabilitation.

METHODS

A cohort of 302 consecutive patients recently treated for ischaemic or valvular heart disease was matched according to the existence of obesity, defined with body mass index (BMI ≥ 30 kg/m(2) ; n = 90 vs. 212), and the advanced grade of obesity (BMI ≥ 35 kg/m(2) ; n = 19 vs. 283). Nutritional risk screening was performed using the standardised NRS-2002 tool.

RESULTS

The mean age of patients was 62.4 ± 11.2 (range 23-86) years; there were more men than women 244 (80.8%) : 58 (19.2%). Group of obese conveyed higher prevalence of ischaemic heart disease than non-obese (OR = 2.69; 95% CI: 1.01-7.20; p = 0.048); while the difference was insignificant for the advanced grade of obesity (n = 17; 89.5%) vs. controls (n = 233; 82.3%; p > 0.05). There was no significant difference in prevalence of other comorbidities (diabetes, glucose intolerance, hypercholesterolaemia, chronic renal and chronic obstructive pulmonary disease) between studied groups (p > 0.05). Utilisation of lipid-lowering drugs was of similar range between the studied groups (p > 0.05), respectively. LVEF (%) was 50.5 ± 8.2 vs. 50.7 ± 7.7 (p > 0.05) and 50.6 ± 7.8 vs. 49.6 ± 10.9 (p > 0.05; Rho = 0.001; p > 0.05), respectively.

CONCLUSION

In studied set of patients, BMI positively correlated with left ventricle dimension and thickness. No significant connection of obesity was found with the prevalence of chronic comorbidities, increased nutritional risk, laboratory diagnostics or systolic function of left ventricle. Existence of obesity paradox in clinical practice was in part reaffirmed with our study.

Perforin-mediated cytotoxicity in non-ST elevation myocardial infarction

The aim of this investigation was to examine the role of perforin (P)-mediated cytotoxicity in the dynamics of tissue damage in patients with non-ST-segment elevation myocardial infarction (NSTEMI) treated with anti-ischaemic drugs. We enrolled 48 patients with NSTEMI in this study [age, 71.5 years; 61.5/76 (median, 25th/75th percentiles)]. The percentage of total peripheral blood P(+) lymphocytes was elevated owing to the increased frequency of P(+) cells within natural killer (NK) subsets, T and NKT cells in patients on day 1 after NSTEMI when compared with healthy controls. Positive correlations were found between cardiac troponin I plasma concentrations and the frequency of P(+) cells, P(+) T cells, P(+) NK cells and their CD56(+dim) and CD56(+bright) subsets during the first week after the NSTEMI. The expression of P in NK cells was accompanied by P-mediated cytotoxicity against K-562 targets at all days examined, except day 21, when an anti-perforin monoclonal antibody did not completely abolish the killing. The percentage of P(+) T cells, P(+) NKT cells and P(+) NK subsets was the highest on the day 1 after NSTEMI and decreased in the post-infarction period. CD56(+) lymphocytes were found in damaged myocardium, suggesting their tissue recruitment. In conclusion, patients with NSTEMI have a strong and prolonged P-mediated systemic inflammatory reaction, which may sustain autoaggressive reactions towards myocardial tissue during the development of myocardial infarction.

Early changes in frequency of peripheral blood lymphocyte subpopulations in severe traumatic brain-injured patients

Infections are leading causes of increased morbidity and mortality of severe traumatic brain-injured (STBI) patients. The mechanism underlying the susceptibility to the infections is still unexplained. The purpose of the study was to investigate changes in frequency of leucocytes subpopulations in peripheral blood of patients with STBI during the course of intensive care treatment. Twenty patients with STBI were included in the study. Healthy age- and sex- volunteers served as control. Peripheral blood samples were taken from these patients at day 1, 4 and 7, and peripheral blood mononuclear cells (PBMC) were isolated. The percentage of T, B lymphocyte, NK and NKT cells as well as monocytes was analysed by simultaneous detection of surface antigens using fluorochrome-conjugated monoclonal antibodies. The two major subsets of T lymphocytes (CD3(+)CD56(-)CD4(+) and CD3(+)CD56(-)CD8(+)) and NK cells (CD3(-)CD56(+dim) and CD3(-)CD56(+bright)) were also analysed by flow cytometry. Extracranial infections were presented in 55% patients with STBI. At day 4, the percentage of T lymphocytes with cytotoxic phenotype significantly diminished and their numbers restored at day 7. The frequency of NKT cells showed the identical time-dependent pattern, whereas the percentage of NK cells diminished on day 4 but did not restore after 7 days. The frequency of B lymphocytes did not change significantly during the time investigated, whereas the percentage of monocytes increased immediately after the injury and gradually diminished. The decrease in cells with cytotoxic phenotype might explain high incidence of susceptibility to infection of patients with STBI.

Human decidual NK cells: unique phenotype and functional properties -- a review

Human decidual NK cells are massively recruited at the site of embryonic implantation (decidua basalis). They differ in many ways from their peripheral blood NK cell counterparts in terms of gene expression, phenotype and functionality. The major subpopulation of decidual NK cells is CD56(bright) whereas the minor subset is CD56(dim), contrasting with the peripheral blood NK cells whose major subpopulation is CD56(dim). Decidual NK cell cytolytic function is much reduced despite the presence of several activating receptors and the essential machinery required for lysis. Decidual NK cells produce a number of cytokines that are not normally secreted by peripheral blood NK cells. Human decidual NK cell potential functions at the maternal-fetal interface are not yet clearly established but several hypotheses are being evaluated, including control of extravillous invasion, control of uterine vascular remodeling, and local anti-viral activity.

The presence of functional mannose receptor on macrophages at the maternal-fetal interface

BACKGROUND

The mannose receptor (MR) is involved in the initiation of the immune response and regulation of homeostasis during inflammation and tissue remodeling.

METHODS

Distribution, endocytosis and possible natural ligand tumor associated glycoprotein-72 (TAG-72) for the MR have been examined by immunohistology, immunocytochemistry and flow cytometry at the maternal-fetal interface, characterized by extensive tissue remodeling.

RESULTS

Contrary to disseminated distribution of the MR positive (MR+) cells in term placenta, the MR+ cells of early pregnancy decidua intimately surrounded glands and followed tissue distribution of CD14 positive cells. The mannose receptor was present on freshly isolated first trimester decidual mononuclear cells and distributed mostly on macrophages (77.08 +/- 10.55%, mean +/- SD). The expression of the MR on CD14 positive cells decreased following 18 h culture (P < 0.01) and was accompanied by the reduction of fluorescein isothiocyanate (FITC)-dextran uptake. PAM-1 anti-MR antibody, mannan and TAG-72 reduced FITC-dextran uptake by decidual macrophages.

CONCLUSIONS

These data indicate that the MR+ macrophages, surrounding early decidual glands, are able to internalize ligands for carbohydrate recognition domain of the receptor, including decidual secretory phase mucin TAG-72.

Perforin expression in peripheral blood lymphocytes and skin-infiltrating cells in patients with lichen planus

BACKGROUND

Current evidence suggests that lichen planus is a T-cell-mediated autoimmune disease in which cytotoxic mechanisms have been poorly investigated.

OBJECTIVES

We investigated the expression of perforin in subpopulations of peripheral blood lymphocytes (PBL) in exacerbation and remission phases of the disease as well as in skin lesions.

METHODS

We performed a simultaneous detection of perforin (intracellular molecule) and cell surface antigens on PBL by flow cytometry, and skin lesions were investigated by immunohistochemistry.

RESULTS

The most interesting finding was a significant increase of perforin expression in cytotoxic T lymphocytes (CD3+ perforin+ cells) in the exacerbation phase of disease (P < 0.05), which was mostly located in the CD8+ subpopulation (CD8+ perforin+) (P < 0.01). Using immunohistochemistry we confirmed the infiltration of T lymphocytes in skin lesions, especially of CD4+ and CD8+ phenotypes, compared with uninvolved (P < 0.05) and healthy skin (P < 0.01). The expression of perforin was also significantly higher in lesional skin compared with nonlesional and healthy skin (P < 0.05).

CONCLUSIONS

Our results clearly show the upregulation of perforin expression in peripheral blood as well as in lesions of patients with lichen planus and therefore suggest an important role for perforin in this autoimmune disease.

Progesterone directly and indirectly affects perforin expression in cytolytic cells

PROBLEM

Decidual lymphocytes (DL) expressing the cytolytic molecule perforin represent approximately 55% of DL in the first trimester of human pregnancy. Progesterone dominates this phase of pregnancy and controls the production of uterine cytokines and growth factors. The aim of this study was to investigate the role of progesterone and progesterone-induced blocking factor (PIBF) on perforin expression in DL and peripheral blood lymphocytes (PBL).

METHOD OF STUDY

Perforin expression was analyzed in PBL and DL incubated either in culture medium or with decidual adherent cells (DAC) and peripheral blood adherent cells (PBAC) and their supernatants with or without progesterone or PIBF. Perforin was detected by flow cytometry in PB and in decidual first trimester pregnancy lymphocytes.

RESULTS

Progesterone in high concentrations directly affects perforin expression in DL but not in PBL. Progesterone in a concentration dependent manner indirectly blocks perforin expression in DL and PBL cultured with adherent cells or their supernatants. PIBF blocked upregulation of perforin expression of DL cultured with DAC, but none of those cultured with PBAC. Similarly, PIBF was inefficient when PBL or DL were cultured with PBAC.

CONCLUSION

Progesterone present in a high concentration locally at the maternal-fetal interface modulates perforin expression in the first trimester pregnancy DL.

Decidual macrophages are the population of decidual adherent cells which regulates perforin expression in cytolytic cells

PROBLEM

We have shown that addition of decidual adherent cells (DAC) to the culture of decidual lymphocytes (DL) prevents the downregulation of perforin expression in these cells. Because DAC are a mixture of various cell populations, the aim is to analyze immunophenotypic characteristics of DAC and to determine which cell population is involved in the regulation of perforin expression.

METHOD OF STUDY

First trimester pregnancy decidual cells were obtained by enzymatic tissue digestion. Decidual cells and peripheral blood lymphocytes (PBL) were centrifuged on Ficoll-Hypaque density gradient and cultured overnight to obtain adherent cells, which were analyzed by flow cytometry and immunocytochemically.

RESULTS

Almost all peripheral blood adherent cells (PBAC) (ca 90%) expressed monocyte/macrophage markers but only 10-20% of DAC. The rest of DAC expressed markers of stromal cells. HLA-DR depleted population of DAC (stromal cells only) could not prevent downregulation of perforin expression in cultured DL and PBL.

CONCLUSION

Decidual macrophages are involved in the regulation of perforin expression in DL.

Progesterone-induced blocking factor inhibits degranulation of natural killer cells

PROBLEM

During the first trimester of pregnancy, nonclassical (CD3-, CD56+, CD16-, perforin [P]bright+) natural killer (NK) cells comprise the major decidual lymphocyte population. These cells, in spite of their high perforin content, exert a low cytolytic activity. Peripheral blood lymphocytes of healthy pregnant women produce progesterone-induced blocking factor (PIBF), which inhibits NK activity. PIBF-producing cells are likely to be present in decidua and might contribute to low decidual NK activity.

METHOD OF STUDY

Decidual cells obtained from elective pregnancy termination were double labeled for CD56 and PIBF. We tested the effect of PIBF on perforin liberation by activated peripheral blood NK cells.

RESULTS

Sixty percent of decidual lymphocytes were CD56 + and expressed PIBF at the same time. PIBF-treated and untreated peripheral blood NK cells were incubated with K-562 cells, and perforin content of target conjugated NK cells was detected with immunocytochemistry. PIBF treatment of peripheral blood lymphocytes significantly reduced lysis of K-562 cells. Among target bound lymphocytes in PIBF-treated samples, we found a significantly (P < 0.01) higher rate of P+ cells than in untreated samples.

CONCLUSIONS

These data suggest that PIBF inhibits cytotoxicity of NK cells via a block of degranulation, and since decidual NK cells are PIBF+, it cannot be ruled out that this effect of PIBF contributes to low decidual NK activity.

Modulation of perforin expression in the decidual and peripheral blood cytotoxic lymphocytes in culture

PROBLEM

Perforin (P) is a cytolytic molecule located in intracellular granules of cytotoxic lymphocytes both in the peripheral blood and decidua of pregnancy. The aim was to analyze the kinetics of P expression during in vitro culture and modulation of P expression by adherent cells, their supernatants and mitogen (PHA) stimulation.

METHOD OF STUDY

P (intracellular antigen) was detected by flow cytometry in the suspension of first trimester pregnancy peripheral blood lymphocytes (PBL) and decidual lymphocytes (DL).

RESULTS

A decrease of the percentage of P+ cells was obtained after 1 hr incubation and was prevented by addition of 30% of decidual adherent cells (DAC) or their supernatants. Upregulation of P expression was obtained when, in addition to adherent cells, DL and PBL were stimulated by PHA. DAC present in the culture in physiological concentrations prevent downregulation of P expression.

CONCLUSION

DAC located in the vicinity of decidual cytotoxic lymphocytes, owing to their unique ability to produce a wide range of substances on demand, contribute to the high level of P expression in the decidua of pregnancy.

Age-related decline of perforin expression in human cytotoxic T lymphocytes and natural killer cells

In this study a flow cytometric technique for detecting cytoplasmic perforin (P) has been used to quantify age-related changes in perforin expression in human peripheral blood lymphocytes (PBL). Proportions of P+ lymphocytes increased after birth, but declined rapidly after the age of 70 years. This was true for both T cells and CD16(+) and CD56(+) natural killer (NK) cells. Children showed in addition to high levels of perforin positive CD8(+) cells a much higher proportion of CD4(+)P+ cells than the other age groups. In elderly individuals there was also a highly significant reduction in mean levels of perforin per cell as compared with all other groups (P < .05 to .001). Adult women had consistently higher mean levels of perforin per cell than adult men for all P+ cell phenotypes. Functional tests clearly showed the deficiency in early spontaneous cytotoxic potential of PBL from elderly persons due to relative P deficiency, which can be corrected by stimulation of cytolytic cells with target cells and interleukin-2 (IL-2). The deficiency in cytolytic activity on the contact with target cells may have implications for antiviral and antitumor immunity in elderly persons.

Membrane phenotype and expression of perforin and serine esterases by CD3- peripheral blood and decidual granular lymphocyte-derived clones

PROBLEM

Human first-trimester pregnancy decidua were found to contain large numbers of perforin (P)-containing cells, which varied in their membrane antigen phenotype. In this study results obtained by analyzing CD3- clones derived from human early pregnancy decidua and peripheral blood are reported.

METHOD OF STUDY

Decidual tissue was obtained from vaginal termination of first trimester normal human pregnancies. CD3- clones were generated by limiting dilution cloning after the depletion of CD3+ lymphocytes. The cell membrane phenotype was determine by flow cytometry. Perforin was detected by fluorescence-activated cell sorter (FACS) analysis of permeabilised cells. Serine esterases (SE) were identified by histochemical staining for BLT-esterase.

RESULTS

Cloned decidual cell populations retained the overall antigenic phenotype of freshly isolated decidual natural killer (NK)-like cells. All CD3- clones, either derived from decidua or from peripheral blood contained perforin. Serine esterases were present in every decidual clone analyzed.

CONCLUSIONS

Limiting dilution cloning allows the clear-cut analysis of homogenous subsets of decidua-derived NK-like clones. The presence of large amounts of perforin in all of the CD3- clones underlines the extensive transcription of the perforin gene by NK-like lymphocytes.