Circulating natural killer cells in Sj?gren's syndrome

Reduced natural killer (NK) cell activity of peripheral blood lymphocytes (PBL) has been reported in a number of diseases including Sj?gren's syndrome (SS). In this study, we used 2 monoclonal antibodies directed toward NK cells (anti-Leu-7 and anti-Leu-11) for determining NK cell activity in 29 patients with SS (9 with primary SS and 20 with secondary SS). The NK activity of PBL was simultaneously determined by the 51Cr release method using K562 as target cells. Contrary to previous reports, we did not find reduced NK activity of PBL in our patients compared with sex- and age-matched healthy controls. Although the percentage of Leu-7+ cells was significantly higher in the patients than in the controls (P less than 0.05), the absolute number of circulating Leu-7+ cells was not different between the groups. The percentage of Leu-11+ cells, however, was not significantly different between the patients and the controls, but the number of circulating Leu-11+ cells was significantly fewer in the patients than in the controls (P less than 0.05). Between the primary and secondary SS groups, no significant differences were found in NK cell activity or in the percentage of Leu-7+ or Leu-11+ cells. Furthermore, we found a significant correlation of NK activity with the percentage of Leu-11+ cells (P less than 0.05) in the controls as well as the SS patients, although a significant correlation was not identified between NK activity and the percentage of Leu-7+ cells.(ABSTRACT TRUNCATED AT 250 WORDS)     

Age- and sex-related changes of the lymphocyte subsets in healthy individuals: an analysis by two-dimensional flow cytometry

The relative and absolute numbers of the peripheral blood lymphocyte (PBL) subpopulations from 156 healthy men and women of different ages (20-99 years old) were studied by the use of monoclonal antibodies (MoAbs) and two-dimensional flow cytometry. The percentage of pan-T MoAb-positive cells decreased with age, which was attributable to a relative decline in the CD8+ suppressor/cytotoxic T cells, more precisely in the CD8+ CD11- cytotoxic T cells. Those of CD4+ Leu-8- helper T cells, CD3+ HLA-DR+-activated T cells, and natural killer subsets (Leu-7+, CD16+, Leu-7+ CD16+ or Leu-7+ CD16-) increased with age. The absolute numbers of most of the lymphocyte subsets examined declined with age except that those of natural killer cell subsets and helper T cells remained unchanged. It should be noted that the PBL subsets differed markedly according to age and sex, the changes being more evident among women.     

Selective generation of erythroid burst-promoting activity by recombinant interleukin 2-stimulated human T lymphocytes and natural killer cells

Because T lymphocytes and natural killer (NK) cells produce a variety of growth factors and interleukin 2 (IL2) modulates the activity of both, we assessed the ability of IL2 to stimulate human T cells and NK cells to produce hematopoietic growth factors detectable in clonogenic marrow culture. Human recombinant interleukin 2 (rIL2) added directly to cultures of human bone marrow that had been depleted of monocytes or depleted of both monocytes and T cells caused no significant alteration of myeloid (CFU-GM) or erythroid colony formation. Conditioned media harvested from rIL2-stimulated (greater than 100 U/mL) peripheral blood mononuclear cells, T cells, Leu-2 cells, and Leu-3 cells all had erythroid burst-promoting activity (BPA) but lacked myeloid colony- stimulating factor (GM-CSF) or CFU-GM-inhibitory activity. These T cells were IL2 receptor-negative, and the addition of anti-IL2 receptor monoclonal antibody (anti-Tac) to T cell cultures did not abrogate this IL2-stimulated BPA production. In addition, Percoll gradient-enriched, large granular lymphocytes (LGL) were separated by fluorescence- activated cell sorting into Leu-11+ (NK) cells and Leu-11- (low-density Leu-4+ T) cell fractions. rIL2 stimulated LGL, Leu-11+ and Leu-11- cells to produce BPA but not detectable GM-CSF or CFU-GM-inhibitory activity. Leu-11+ (NK) cells were Tac-negative from days 0 through 14 of culture. We conclude that rIL2 at high concentrations stimulated T cells, Leu-2 and Leu-3 cell subsets, LGL, and NK cells to produce BPA but not GM-CSF and that this stimulation may be mediated by an IL2 receptor distinct from Tac or by an epitope of the IL2 receptor not recognized by the anti-Tac antibody.     

Phenotypic analysis of lamina propria lymphocytes. Predominance of helper-inducer and cytolytic T-cell phenotypes and deficiency of suppressor-inducer phenotypes in Crohn's disease and control patients

To better define the nature of intestinal T cells, the phenotypes of isolated lamina propria lymphocytes (LPL) were determined in both Crohn's disease patients and control patients using combinations of monoclonal antibodies that have been found to correlate with particular immunoregulatory functions. Isolated LPL and autologous peripheral blood lymphocytes (PBL) were stained with multiple combinations of monoclonal antibodies and studied by dual immunofluorescence flow cytometry. In LPL, compared with PBL, there was a significant increase in the proportion of T cells having the Leu-3+, Leu-8- and Leu-3+, 2H4- phenotypes (associated with helper-inducer function) and a corresponding decrease in the proportion of T cells having the Leu-3+, Leu-8+ and Leu-3+, 2H4+ phenotypes (associated with suppressor-inducer function). It was also found that in LPL, compared with PBL, the percentage of cells with the Leu-2+, Leu-15+ phenotype (associated with suppressor-effector function) was significantly lower. However, the percentage of T cells with the Leu-2+, 9.3+ phenotype (associated with cytolytic function) was similar in PBL and LPL in control patients. There were no major differences comparing Crohn's disease patients with control patients, except that the proportion of Leu-2+, 9.3+ lymphocytes was higher in PBL in Crohn's disease patients. These results show that the lymphocyte subpopulations in the lamina propria differ from those in peripheral blood in having predominantly the phenotypes of helper-inducer and cytolytic T cells, whereas the phenotypes of suppressor-inducer cells and activated suppressor cells are less frequently observed.     

Absence of circulating natural killer (NK) cells in a child with erythrophagocytic lymphohistiocytosis lacking NK cell activity

A 5-year-old girl who was diagnosed as having erythrophagocytic lymphohistiocytosis died at age 9 years. Peripheral lymphocytes from the patient persistently lacked natural killer (NK) cell activity during the 4-year observation period: the percent lysis values as measured by a 4-hr 51Cr release assay at a 40:1 effector:target ratio were below 1.0% against K562 and Molt-4 cells as compared with the normal lymphocyte value (mean +/- SD) of 46.2% +/- 5.8% and 43.9% +/- 6.7%, respectively. The patient's lymphocytes never developed NK cell activity by their incubation with target cells for longer time periods or by their stimulation with interferon-alpha, interleukin-2, or polyinosinic-polycytidilic acid. Single cell-in-agarose assay showed the absence of target-binding cells (TBCs): TBC numbers were below 0.3% as compared with the normal lymphocyte value of 8.1% +/- 1.3% (mean +/- SD). Flow cytometry showed a marked decrease in Leu-7+ cells (1.7%) and the absence of Leu-11+ cells (0.4%) in the peripheral blood. These results first demonstrate a case of erythrophagocytic lymphohistiocytosis in which there is the lack of NK cell activity due to the absence of circulating NK cells.     

Studies on natural killer cells in chronic myeloid leukemia patients in remission.

In our earlier studies, the natural killer (NK) cell mediated cytotoxicity was found to be impaired in 55% of chronic myeloid leukemia (CML) patients in remission (low NK responders), while the rest exhibited normal range of cytotoxicity (normal NK responders). In the present investigations probable factors contributing to the impaired NK activity of low NK responder CML patients have been analyzed. Peripheral blood lymphocytes (PBL) from both low and normal NK responder CML patients possessed normal percentages of HNK-1+, CD3+ and CD8+ cells. The proportion of HNK-1+ cells and CD8+ cells in low density fractions (LDF) and high density fractions (HDF) respectively of Percoll separated PBL from low and normal NK responder CML patients and healthy donors was comparable. However, the NK activity of LDF cells of low NK responder CML patients was much lower. Also, HDF cells from low NK responder CML patients exhibited a regulatory effect on NK cytotoxicity of PBL from healthy donors. Therefore, it is likely that the presence of suppressor cells and perhaps an intrinsic inability of HNK-1+ cells may together contribute to the impaired NK cytotoxicity of low NK responder CML patients.     

Effect of smoking on natural killer cell activity in the lung

We investigated the effect of smoking on natural killer (NK) cell activity and distribution in bronchoalveolar lavage fluid (BALF) and blood. Initially, BALF NK cell activity was lower than the blood NK cell activity both in non-smokers (NS) and smokers (S). Following 24 hour culture, NK cell activity markedly increased in NS but not in S. Percentage distribution of Leu-7+ cells and Leu-11+ cells in BALF was similar in NS and S. But the BALF NK cell activity was significantly augmented by IL-2 or OK-432 (a streptococcal preparation) in NS. It appears that smoking reduces NK cell activity in BALF. It is conceivable that the low NK cell activity in BALF in S might contribute to increased incidence of infection and malignancy in smokers.     

Deficient natural killer (NK) cells in paroxysmal nocturnal haemoglobinuria (PNH): studies of lymphoid cells fractionated by discontinuous density gradient centrifugation

Non-adherent, non-B lymphoid cells from six patients with PNH and six healthy subjects were fractionated by Percoll discontinuous density gradient centrifugation (DDGC). The cell distribution pattern, NK cell activity (NKA), large granular lymphocytes (LGL) count and surface marker phenotypes were studied. The distribution patterns of patients' cells did not significantly differ from the controls. The peak of the NKA was found in low density fractions where the maximum counts of LGL, Leu-7+2- cells and Leu-11+ cells were present. The NKA and the proportion of Leu-7+2- cells and Leu-11+ cells were significantly lower in patients with PNH (P less than 0.001 for NKA and surface phenotypes; P less than 0.02 for LGL counts). NKA in the Percoll fractions was correlated with the counts of LGL (r=0.69, P less than 0.001), Leu-7+2- cells (r = 0.75, P less than 0.001) and Leu-11+ cells (r = 0.89, P less than 0.001). Therefore, we concluded that NKA is deficient in PNH because of decreased NK cell counts.     

Decreased natural killer cell activity versus normal natural killer cell markers in mononuclear cells from patients with smouldering leukemia

Peripheral blood (PB) and bone marrow mononuclear cells from 23 patients with smouldering leukemia were analyzed for natural killer (NK) cell activity and various surface cell markers. Significantly reduced NK activity was detected in the patients' PB compared with the activity in the healthy controls (p less than 0.0005). A similar difference in NK cell activity between the 2 groups was also observed in bone marrow mononuclear cells (p = 0.005). In contrast, no significant differences in cells positive for the NK cell markers Leu-7 and Leu-11b were found between patients and controls, either in PB or in bone marrow. The patients' PB and bone marrow mononuclear cells had, however, a reduced percentage and absolute number of Leu 3a+ and T8+ cells. Patients with smouldering leukemia have immunological derangements which may make them predisposed for the later development of florid leukemia.     

An immunological and clinical evaluation of combined TAE-LAK adoptive immunotherapy

To clarify the immunological effects of transcatheter arterial embolization (TAE) therapy for hepatocellular carcinoma (HCC), various immunological parameters were measured before and after TAE respectively. In most effective group of which AFP levels at first week after TAE therapy had decreased more than 50% compared with those before TAE, the percentage of OKT-4 and IL-2R positive cells in the peripheral blood lymphocytes (PBL) had significantly increased in number. In addition, IL-1, TNF, IL-2 and LAK activity were also enhanced by it. These immunological enhancement after TAE therapy was suggested to be a favourite condition for transferring LAK cells to the patients with HCC. Therefore the combination therapy with TAE and LAK-adoptive immunotherapy was conducted in 12 patients with HCC. Partial response to it was obtained in one case and minor response in three. However, no effectiveness was also found in eight (Progressive Disease: 1 case, No Change: 7 cases). Immunological response after combined TAE-LAK adoptive immunotherapy revealed that NK activity and LAK activity were markedly enhanced. Furthermore, the percentage of OKT-11+, IL-2R+ and Leu-7- 11c+ cells in the PBL had increased in number with statistically significant differences and OKT-8+ cells had increased in relative number. In conclusion, this study suggested that this combination therapy might be a well designed immunological and clinical therapy for HCC because it was done under the condition of well enhanced immunological parameters against tumors.     

Two populations of CD56 (Leu-19)+/CD16+ cells in bone marrow transplant recipients.

Bone marrow transplant (BMT) recipients are severely immunocompromised during the early post-transplant period as their immune systems recapitulate. Among the first cells to repopulate the peripheral blood are natural killer (NK) cells. Studies in normal subjects have revealed that the majority of NK cells express CD16 and CD56 (Leu-19). Such NK cells express low density, dim, Leu-19 (Leu-19D+). A small percentage of high-density, bright, Leu-19 cells (Leu-19B+) which are CD16- have also been reported in normal subjects. In this study we observed that peripheral blood mononuclear cells (PBMC) from BMT recipients contained two distinct populations of Leu-19+ cells that co-expressed CD16 and these populations could be separated on the basis of differential Leu-19 and CD16 fluorescence intensities. Leu-19B/CD16D and Leu-19D/CD-16B cells were present in four of nine BMT patients studied. Cells from one BMT recipient with a very large expansion of the Leu-19B+ population (46% of PBMC by flow cytometry) were studied in detail. While this patient is not characteristic of all BMT recipients, the large number of Leu-19+ cells that could be isolated from him allowed extensive analysis of a previously unreported population of cells. Our data suggest that BMT recipients can be an important group of subjects to evaluate NK cell subsets as these cells mature and, presumably, differentiate in a regenerating immune system.     

Malignant clonal expansion of large granular lymphocytes with a Leu- 11+, Leu-7- surface phenotype: in vitro responsiveness of malignant cells to recombinant human interleukin 2

A 14-year-old Japanese female with neutropenia showed malignant proliferation of the large granular lymphocytes (LGLs). These LGLs were E rosette+ and Fc(IgG) receptor+ and therefore are referred to as T gamma lymphocytes. They were also Leu-11+ and OKT11+; however, they were clearly negative for Leu-7, OKT3, OKT8, OKM1, and HNK-1 antigens as well as for terminal deoxynucleotidyl transferase activity. Karyotype analysis revealed 47, XXX. The LGLs showed no rearrangement of T cell receptor C beta genes. The natural killer (NK) cell activity against K562 target cells was low, but was significantly augmented after stimulation by recombinant human interleukin 2 (IL 2) in contrast to minimal NK boosting by recombinant human gamma-interferon (gamma- IFN). Such a unique responsive ability to lymphokines was quite similar to that noted in fetal and cord blood cells. These LGLs also demonstrated a considerable increase in antibody-dependent cell- mediated cytotoxicity (ADCC) and lymphokine-activated killer (LAK) activity after a short incubation with IL 2. Although in a resting stage they showed no IL 2 receptor expression as examined by anti-Tac antibody, Tac antigen appeared after IL 2 treatment followed by a marked increase in 3H-thymidine incorporation and a remarkable production of gamma-IFN. To investigate the mechanism of neutropenia, in vitro IL 2-stimulated coculture studies of these cells with normal bone marrow cells were performed. Colony formation of myeloid progenitors (CFU-C) was significantly suppressed. In addition, the conditioned medium from IL 2-stimulated LGLs indicated a remarkable suppression of CFU-C. These results suggest that these LGLs with a Leu- 11+, Leu-7- surface phenotype might belong to a unique subset of pre-NK cells that are functionally and phenotypically similar to those represented at any early stage of human ontogeny and that they strongly express Tac antigen under the influence of IL 2 administration, followed by remarkable cell proliferation and gamma-IFN production.     

Sialyl SSEA-1 antigen as a carbohydrate marker of human natural killer cells and immature lymphoid cells

The distribution of a carbohydrate antigen, the sialyl SSEA-1 (sialyl Lex-i), in human lymphoid cells was investigated by flow cytometry with a specific monoclonal antibody, MoAb FH-6. We concluded that the lymphocytes positive for the sialyl SSEA-1 antigen present in normal peripheral blood (PB) are natural killer (NK) cells since the positive cells had an NK activity toward K562 cells, and most of the sialyl SSEA- 1+ cells were simultaneously positive for Leu-11 (CD-16) and Leu-19. Essentially, no T and B cells, defined by Leu-4 (CD3) and Leu-16 (CD20), were positive for the sialyl SSEA-1 antigen in PB samples taken from healthy donors and patients with disorders unrelated to lymphoid malignancies. Among the malignant lymphoid cells, many sialylated SSEA- 1+ cells were observed in large granular lymphocyte (LGL) leukemia cells and some acute lymphoblastic leukemia (ALL) blasts, but not in CLL cells or malignant lymphoma cells. Sialyl SSEA-1 was also positive in some cultured human lymphoid cell lines. We conclude that expression of the sialyl SSEA-1 antigen is strictly limited to a distinct population of NK cells among the mature lymphocytes in normal PB, but the antigen is present in a wide range of immature lymphoblasts of T- and B-cell lineages as well as the NK-cell lineage. The sialyl SSEA-1 antigen disappears from the surface of immature lymphocytes of T- and B- cell lineages during the course of maturation.     

Phenotypic and functional analysis of peripheral blood lymphocytes during interferon-alpha 2b therapy in multiple myeloma patients with low tumor mass.

BACKGROUND. IFN-alpha has recently been shown to prolong the remission phase in MM patients with low tumor mass. So far, it is not known whether IFN-alpha exerts its effect directly on the myeloma cells or is mediated by modulation of the host response. METHODS. The immune status of 12 multiple myeloma patients with low tumor mass (10 in remission phase, 2 with stage IA disease) was investigated by phenotypic and functional analyses before, after 3, and after 6 months of recombinant interferon-alpha 2b (IFN-alpha) therapy. RESULTS. Phenotyping of peripheral blood lymphocytes (PBL) revealed a significant decrease of HLA-DR+ (P = 0.01) and CD20+ (P = 0.04) cells after 6 months of therapy. Two-color phenotyping of purified T cell populations (PBT) showed a significant increase of CD4+ CD11b+ cells (P = 0.01) after 6 months of therapy. Functional analyses were carried out on PBL (NK cell-mediated cytotoxicity) and PBT (alloreactive cytotoxicity, CTL; IL2-induced cytotoxicity, LAK activity). NK and CTL activities were poorly influenced by IFN-alpha treatment, whereas LAK activity showed a significant increase (P = 0.007). Any significant association between these immunological changes and the disease status was questioned by the lack of differences between MM in relapse and MM with stable disease at the sixth month of IFN-alpha therapy. CONCLUSIONS. i) IFN-alpha in MM with low tumor mass may exert its therapeutic activity by directly acting on the tumor cells; ii) the parameters which have been used in this study are not appropriate to monitor the immunological effects (if any) of IFN-alpha therapy.     

Local immune mechanisms in inflammatory bowel disease and colorectal carcinoma. Natural killer cells and their activity

Mononuclear cell (MNC) populations isolated from intestinal mucosa, mesenteric lymph nodes, and peripheral blood have been assessed for their natural killer (NK) (Leu-7+) cell proportions and NK cell activity against K-562 erythroleukemic target cells. In peripheral blood, normal proportions of Leu-7+ cells were found in patients with Crohn's disease or ulcerative colitis, whereas increased proportions in colorectal carcinoma may have been related to the higher mean age of these patients. Low proportions of Leu-7+ cells (less than 3%) were present in intestinal MNCs in Crohn's disease, ulcerative colitis, colon cancer, and miscellaneous intestinal diseases. All groups of patients had diminished NK activity of peripheral blood MNCs compared with a group of healthy controls. Intestinal NK cell activity from histologically normal mucosa correlated with autologous peripheral blood NK cell activity (p less than 0.001) but no such correlation was seen for patients with inflammatory bowel disease. Mucosal or nodal NK cell activity showed a wide range of activity but did not relate to the underlying disease, mucosal histopathology, drug therapy, or, in patients with cancer, Dukes' grading. Intestinal MNCs from all patient groups responded to stimulation with lymphoblastoid interferon, except in a small number of patients whose unstimulated activity was not detectable. In conclusion, the NK cell on intestinal mucosa behaves similarly in various intestinal diseases. However, the disparity between NK activity of autologous peripheral blood and intestinal MNCs in inflammatory bowel disease highlights the difficulty in extrapolating peripheral blood findings to mucosal immune events.     

Generation of non MHC restricted killing in non-cytotoxic T-lymphocytes from leukaemia patients

Experiments were undertaken to determine whether the depression of natural killer (NK) activity previously observed in the peripheral blood lymphocytes (PBL) of leukaemia patients in remission extended to NK-like precursors in the blood. T-lymphocytes (E+) from leukaemia patients and normal subjects were depleted of IgG Fc-receptor-bearing (gamma FcR) fresh NK cells by passage over immune complex-coated monolayers. gamma FcR - E + PBL were cultured alone or with DAUDI cells. On day 5 of culture, cytotoxicity toward the NK-sensitive cell lines K562 and MOLT-4 was evaluated in the responder lymphocytes of leukaemia patients and controls. Negligible NK-like cytotoxicity was found in both FcR - E + PBL responder populations cultured alone. By contrast, stimulation with DAUDI induced high levels of K562 and MOLT-4 cytotoxicity in leukaemia as well as in normal responder cells. Complement-mediated cytotoxicity experiments using various McAb demonstrated that in both normal and leukaemia cultures NK-like effectors react with the pan-T OKT3 McAb and with the OKT11 McAB directed to the SRBC receptor, but not with Leu 1 1b and OKM1 McAbs, directed against antigens expressed on peripheral blood NK cells. Fractionation of the responder cells on discontinuous Percoll gradients showed that most of this activity was present in the highly dividing blast cell fraction.     

Expression of the Chediak-Higashi lysosomal abnormality in human peripheral blood lymphocyte subpopulations

Fusion of lysosomes to form a giant cytoplasmic inclusion is a major abnormality expressed by multiple hematopoietic and non-hematopoietic cell types in Chediak-Higashi (C-H) patients. In this study, the extent of involvement of lymphoid cell subpopulations was defined. Purified populations of B cells, natural killer (NK) cells, and helper T cells were obtained from two C-H patients and normal controls by immunofluorescence staining of their blood mononuclear cells with the monoclonal antibodies HB-2, Leu-7, or Leu-3 followed by fluorescence- activated cell sorting. Cytochemical and ultrastructural analyses as well as functional assays were performed to determine whether or not the C-H lysosomal abnormality was expressed in the different lymphocyte subpopulations. B cells expressed the C-H defect following activation and differentiation. All of the Leu-7+ cells and a significant proportion of the Leu-3+ cells displayed the C-H abnormality. These Leu- 3+ cells share the NK lineage characteristics of granular lymphocyte morphology and the capacity to bind to NK cell targets. In contrast, the C-H abnormality was not observed in non-NK target-binding cells with T helper phenotype, in which clusters of lysosomes formed a normal Gall body. Moreover, T cell functions were unimpaired in C-H patients. These observations raise the issue of the lineal relationship between granular and nongranular lymphocytes typed as T cells on the basis of cell surface antigen markers.     

Depressed lymphokine-activated killer activity and analysis of the precursor cells in peripheral blood of patients with hepatocellular carcinoma

The in vitro lymphokine-activated killer activity and natural killer activity of peripheral blood mononuclear cells from 33 patients with hepatocellular carcinoma were investigated. Lymphokine-activated killer and natural killer activities of patients were significantly decreased compared with those of healthy volunteers. Peripheral blood mononuclear cells showed significantly lower lymphokine-activated killer and natural killer activities in patients with larger tumors (greater than or equal to 5 cm in diameter) than in patients with smaller tumors (less than 5 cm in diameter). Of 20 patients with larger tumors, 8 and 6 generated very little or no lymphokine-activated killer and natural killer activities. respectively. Lymphokine-activated killer precursors and natural killer cells were present mainly in the Leu-11+ fraction and partially in the Leu-7+ fraction in patients and normal volunteers. A flow cytometric study showed that the percentage of Leu-7+ 11+ and Leu-7-11+ fractions in peripheral blood mononuclear cells was lower in patients than in normal volunteers. The percentages of Leu-7-11+ and Leu-7+ 11+ fractions were diminished in the peripheral blood mononuclear cells of the patients with little or no lymphokine-activated killer activity. It is suggested that deficient lymphokine-activated killer and natural killer activities partially results from a reduction in the number of their precursor cells in patients with hepatocellular carcinoma.     

Effects of adenine arabinoside on cellular immune responses in patients with chronic hepatitis B

The lymphocyte subsets in the peripheral blood and in liver biopsies from 4 patients with chronic hepatitis B obtained about 2-7 weeks before and after treatment with adenine arabinoside (Ara-A) were studied by a peroxidase-labeled antibody method using monoclonal antibodies against Leu-1, Leu-2a, Leu-3a, Leu-7 and Leu-10 antigens. In the peripheral blood, the percentage of Leu-2a+ (cytotoxic/suppressor) cells was significantly reduced and the ratio of Leu-3a+ (helper/inducer) to Leu-2a+ cells was increased after the treatment with Ara-A. In the liver biopsies, the numbers of Leu-1+ (pan T) and Leu-2a+ cells were significantly decreased after the treatment with Ara-A. As a result, the Leu-3a+/Leu-2a+ ratio was significantly elevated in the liver after the therapy. The majority of lymphocytes distributed at sites of hepatocytic necrosis were positive for Leu-2a. The reduced numbers of Leu-1+ and Leu-2a+ cells after the treatment were mainly due to the decrease of these cells infiltrating to the sites of hepatocytic necrosis. The numbers of other subsets (Leu-3a+, Leu-7+ and Leu-10+) changed without any specific tendency both in the peripheral blood and in the liver biopsies after the treatment. With respect to viral replication, most of the patients showed a decrease of serum DNA polymerase activity or demonstrable intrahepatic HBsAg and HBcAg after the treatment. These data suggest that T cell-mediated cytotoxicity against HBV-infected hepatocytes is diminished after treatment with Ara-A.     

CD5 positive immunoregulatory B cell subsets

B-chronic lymphocytic leukemia (B-CLL) is a heterogeneous disease often expressed as a clonal expansion of CD5+ B cells. We report the characterization of CD5+ B cells from two unique B-CLL patients. Cells from patient 1 coexpressed CD5 (leu-1), CD19 (Leu-12), CD20 (B1), and HLA-DR; they were CD10 (J5), CD21 (B2), CD22 (Leu-14), CD25 (IL2-R1), PCA-1, surface, and cytoplasmic Ig negative. They suppressed normal peripheral blood lymphocyte (PBL) pokeweed mitogen (PWM) -stimulated immunoglobulin (Ig) synthesis greater than 80%. Cells from patient 2 were CD5 (Leu-1), CD19 (Leu-12), CD20 (B1), CD21 (B2), CD22 (Leu-14), HLA-DR, IgM, and kappa positive. They were negative for CD10 (J5), CD25 (IL2-R1), and PCA-1. These cells did not suppress normal PBL PWM-stimulated Ig synthesis but produced a monoclonal IgM kappa protein with rheumatoid factor-like activity. These observations suggest that there are different CD5+ B cell subsets, one immunosuppressive and the other autoreactive.