Effects of immunosuppressive therapy with prednisolone on B and T lymphocyte function in patients with chronic type B hepatitis

B and T lymphocyte function was studied in 10 patients with chronic type B hepatitis before, during and after a 28-day course of prednisolone therapy. Lymphocyte function was assessed by measuring the in vitro synthesis of immunoglobulin by peripheral blood mononuclear cells stimulated with pokeweed mitogen and by assaying lymphocyte proliferation in response to B and T cell mitogens. During high dose prednisolone therapy, there was a decrease in immunoglobulin synthesis by peripheral blood mononuclear cells and in lymphocyte proliferation to all mitogens. Studies using separated B and T cells showed that prednisolone treatment led to a decrease in both helper and suppressor T cell function but an enhancement of primary B cell function. When prednisolone was withdrawn, lymphocyte function rapidly returned to baseline levels. During prednisolone therapy, serum aminotransferase activities decreased by an average of 50%. In all patients, there was a subsequent rebound increase in serum aminotransferase activities 4 to 10 weeks after withdrawal of prednisolone. This was accompanied by a striking increase in suppressor T lymphocyte activity without significant changes in either helper T cell or B cell function. The close correlation between changes in helper and suppressor T lymphocyte function and serum aminotransferase activities during and after immunosuppressive therapy suggests that immunoregulatory T lymphocytes may play an important role in the pathogenesis of chronic type B hepatitis.     

Isolation of intestinal mononuclear cells from colonoscopic biopsies for immunofluorescence analysis by flow cytometry

A method for isolating and characterizing intestinal lymphoid cells from colonoscopic biopsies is presented. Intraepithelial lymphocytes were separated from the lamina propria by incubation in edetic acid (EDTA) and lamina propria lymphoid cells isolated by incubation in collagenase followed by Ficoll-Hypaque density flotation. Quantitation of T lymphocyte helper (OKT4) and suppressor (OKT8) cells was performed using monoclonal antibodies to cell surface markers and analyzed on a flow cytometer. The isolation procedure yielded approximately 400,000 lamina propria cells and 100,000 intraepithelial cells per sample, with better than 90% viability. Surface marker analysis demonstrated significant differences in the ratios of helper to suppressor cells between the intraepithelial lymphocytes and the lamina propria lymphocytes. These demonstrate the feasibility of lymphoid cell isolation from colonoscopic biopsy specimens for surface marker analysis by flow cytofluorimetry. These techniques could prove important in the study of immune mechanisms in inflammatory bowel diseases.     

Effect of hypo- and hyperthyroidism on the balance between helper and suppressor T cells in rats

The proportion of total, helper and suppressor T lymphocytes among mononuclear cell preparations from blood and spleen of rats made hypo- and hyperthyroid was measured using three monoclonal antibodies specifically directed against total, helper and suppressor T cells. Compared to normal rats, hypothyroid (thyroidectomized or treated with 6-propyl-2-thiouracil (PTU) rats had a decreased proportion of suppressor T cells in the spleen, which produced an increase in the helper/suppressor T cells ratio. The opposite alterations (increased suppressor T cells and decreased ratio) was found in the blood of the same animals. Triiodothyronine (T3) added to PTU in the drinking water prevented these alterations. Animals treated with high doses of T3 for 17 days did not develop any alteration either in the proportions or in the ratio of helper/suppressor T cells. Our results suggest that hypothyroidism but not hyperthyroidism alters the normal balance between helper and suppressor T cells in rats.     

Abnormalities in intestinal mucosal T cells in homosexual populations including those with the lymphadenopathy syndrome and acquired immunodeficiency syndrome

Enteric infections are common in homosexual men. We have characterized the phenotypic distribution of small intestinal mononuclear cells among healthy homosexual men, homosexual men with lymphadenopathy syndrome, homosexual men with acquired immunodeficiency syndrome (AIDS), and a group of healthy heterosexual men. Total numbers of T lymphocytes in the small intestinal mucosa were significantly decreased in homosexual men with lymphadenopathy syndrome and AIDS. This decrease was most striking among the Leu-3a T-cell subset usually associated with helper/inducer function. The proportion of mucosal T cells reacting with Leu-2a (cytotoxic/suppressor phenotype) and lymphoid cells having the T305 antigen was significantly increased only in AIDS subjects. Both lymphadenopathy syndrome and AIDS subjects had a significant reversal of the normal mucosal helper/suppressor T-cell ratio. Mucosal helper/suppressor T-cell ratios and the distribution of mucosal mononuclear cells were normal in healthy homosexual men, although the same individuals had reversed helper/suppressor ratios among circulating T cells. Enteric infections in healthy homosexual men likely reflect sexual practices, and not a primary abnormality in intestinal mucosal immunity. In contrast, specific abnormalities in intestinal mucosal immunity may contribute to the persistent and opportunistic enteric infections that occur in AIDS.     

Altered balance of immunoregulatory T lymphocyte subsets in autoimmune thyroid diseases

Three monoclonal antibodies recognizing cell surface antigens of total peripheral (OKT3), helper/inducer (OKT4) and suppressor/cytotoxic (OKT8) T lymphocytes were used by an indirect immunofluorescence technique to enumerate peripheral T lymphocytes in 25 patients with Graves' disease (including 4 euthyroid Graves' patients), 16 patients with Hashimoto's thyroiditis and 22 normal controls. Total lymphocyte count and percentages of overall T and helper/inducer T cells among peripheral lymphocytes in these conditions showed no significant difference from those of the controls. Percentage of suppressor/cytotoxic T cells, however, was decreased in Graves' disease patients with or without hyperthyroidism. The ratio of helper/inducer T cells to suppressor/cytotoxic T cells was increased in Graves' disease population and slightly increased in hypothyroid Hashimoto's thyroiditis patients. The ratio correlated with the mitogenic response of peripheral mononuclear cells to phytohaemagglutinin, but not with the serum levels of thyroid hormones nor with the titres of thyroid autoantibodies. These findings are in accordance with the results of previous functional studies and indicate possible defects in suppressor T lymphocytes in autoimmune thyroid disease.     

Increased level of HLA-DR-expressing T lymphocytes in peripheral blood from patients with idiopathic dilated cardiomyopathy

Peripheral blood leukocytes from 14 patients with idiopathic dilated cardiomyopathy (IDC), 13 patients with ischemic congestive heart failure, and 12 controls were characterized using different antibodies. The proportions of B lymphocytes, T lymphocytes, and the different T lymphocyte subsets were estimated. No difference between the three groups could be found in the various T and B cells subpopulations. Using a two-color direct immunofluorescence technique, the occurrence of circulating T helper/inducer (Leu-3a) and T cytotoxic/suppressor cells (Leu-2a) expressing HLA-DR antigens was examined. Only IDC patients demonstrated increased levels of HLA-DR-positive T helper/inducer cells (2.8 +/- 2.4%) and T cytotoxic/suppressor cells (2.8 +/- 2.3%) as compared with patients with ischemic congestive heart failure (0.8 +/- 0.7 and 1.0 +/- 1.0%, respectively) and controls (0.6 +/- 0.5 and 0.9 +/- 0.6%, respectively). When individual IDC patients were studied, 4 out of 12 patients had an increased level of HLA-DR-expressing T helper/inducer cells, and 7 out of 12 patients had elevated HLA-DR-positive T cytotoxic/suppressor cells. The findings suggest that activation of the T lymphocytes may be of importance in the pathogenesis of IDC.     

Quantitative changes in T helper or T suppressor/cytotoxic lymphocyte subsets that distinguish acquired immune deficiency syndrome from other immune subset disorders

Quantitative measurements of the immune cell subgroups, T helper (Leu 3+/OKT4+) cells and T suppressor/cytotoxic (Leu 2+/OKT8+) cells, were made in patients having acquired immune deficiency syndrome (AIDS) with Kaposi's sarcoma and in patients with AIDS and opportunistic infection, as well as in three other relevant populations. These included patients with lymphadenopathy syndrome, e.g., homosexually active males with lymphadenopathy who sought medical care for additional symptoms, and healthy male homosexuals, as well as a control population. Decrease in the number of T helper cells is characteristic of AIDS with Kaposi's sarcoma or opportunistic infection. Augmentation of the T suppressor/cytotoxic cell population is rare in AIDS with Kaposi's sarcoma but is more frequent in AIDS with opportunistic infection. Augmentation of the T suppressor/cytotoxic cell population, however, may occur in a variety of circumstances, including cytomegalovirus and other viral infections, in healthy, homosexually active males, and in otherwise healthy hemophiliac subjects receiving factor VIII treatment. Reduced T helper:T suppressor/cytotoxic cell ratio can be caused by either decrease in the number of T helper cells or augmentation of the T suppressor/cytotoxic cell population. Lowered T helper:T suppressor/cytotoxic cell ratio does not, by itself, help to distinguish between AIDS and other causes of reduced ratios. Quantitative measurements are needed to define the T subset changes. AIDS is characterized by decrease in the number of T helper cells and reduced T helper:T suppressor/cytotoxic cell ratio. The T helper (Leu 3+) and T suppressor/cytotoxic (Leu 2+) cell subpopulations can change independently. Identification of decrease in the number of T helper cells as an alteration that occurs independently of numerical change in other lymphoid subpopulations, such as T suppressor/cytotoxic cells and B cells, and the close association of the decrease in the number of T helper cells with AIDS are consistent with a distinct pathogenesis (and cause) for AIDS.     

Modulation of T-lymphocyte differentiation antigens: potential relevance for multiple sclerosis.

Effects of the anti-T-cell monoclonal antibodies OKT3, OKT5, and OKT8 on T-cell surface properties and cell functions were evaluated. Incubation of mononuclear cells isolated from peripheral blood for 48 hr with each monoclonal antibody in the absence of complement resulted in modulation of their respective surface antigens; i.e., the number of cells detected by immunofluorescence as positive for the T3, T5, and T8 surface antigens was reduced. T3, T5, and T8 antigens modulated independently. A radiolabeled second antibody technique confirmed modulation by OKT3 and OKT8 and indicated that T-cell differentiation antigens can regenerate in culture. Incubation of mononuclear cells with OKT3 increased the number of sheep erythrocyte-binding lymphocytes (E+-rosetting cells) and markedly increased the number of avidly E+-rosetting cells. Incubation with OKT8 reduced the number of E+- and of avidly E+-rosetting cells. OKT3 induced both mitogenic reactivity and suppressor cell activity; cells modulated by OKT8 exhibited reduced mitogenic reactivity and reduced suppressor cell function. The decreases in total T cells, in avid T cells, in suppressor cell number, and in suppressor cell function that follow modulation by OKT8 mimic changes observed in multiple sclerosis patients.     

Transformed T lymphocytes infected by a novel isolate of human T cell leukemia virus type II

Human T cell leukemia virus type II (HTLV-II) has been isolated from a patient (Mo) with features of leukemic reticuloendotheliosis (LRE) and from a patient with acquired immunodeficiency syndrome (AIDS). We have obtained another isolate of HTLV-II from a patient (CM) with severe hemophilia A, pancytopenia, and a 14-year history of staphylococcal and candidal infections but no evidence of T cell leukemia/lymphoma, AIDS, or LRE. Fresh mononuclear cells and cultured lymphocytes from CM express retroviral antigens indistinguishable by molecular criteria from HTLV-IIMo. Leukocyte cultures from CM yield hyperdiploid (48,XY, +2, +19) continuous lymphoid lines; human fetal cord blood lymphocytes (CBL) are transformed by cocultivation with these CM cell cultures but retain normal cytogenetic constitution. Electron microscopic examination of the CM cultures and transformed CBL reveals budding of extracellular viral particles, intracellular tubuloreticular structures, and viral particles contained within intracellular vesicles. CM cell cultures and the transformed CBL do not require exogenous interleukin 2, have T cell cytochemical features and mature T helper phenotypes, and exhibit minimal T helper and profound T suppressor activity on pokeweed mitogen-stimulated differentiation of normal B cells. These characteristics, which are similar to those observed with the first HTLV-II isolate, may represent properties of all HTLV-II-infected T cells.     

Papular lesions and cutaneous lupus erythematosus: a comparative clinical and histological study using monoclonal antibodies

Skin biopsies from 13 patients with papular lesions thought to be cutaneous lupus erythematosus were analyzed by light microscopy, direct immunofluorescence and immunohistochemically and compared to 22 biopsies from patients with discoid lupus, subacute cutaneous lupus erythematosus and acute cutaneous lesions of SLE. Papular lesions demonstrated fewer florid dermal and epidermal changes but a similar marked mononuclear cell infiltrate which in all groups was composed predominantly of T lymphocytes (68.4 +2- 11.2 SD) with the mean helper: suppressor (corrected Leu 3a:T8) ratio 1.73 +/- 0.60 SD. HLA-DR expression on keratinocytes was present in 20 patients, including 4 with papular lesions, and was strongly associated with liquefactive degeneration (chi 2, p less than 0.001), the hallmark of dermoepidermal junctional damage.     

Trypanosoma cruzi: deficient lymphocyte reactivity during experimental acute Chagas'' disease in the absence of suppressor T cells

Infection of mice with Trypanosoma cruzi has been shown to lead to an impaired ability of lymphocytes to proliferate in response to mitogenic stimulation which is manifested during the acute period of the disease. A possible involvement of suppressor T lymphocytes has been postulated by other authors and was investigated in this work as a part of our efforts to disclose the mechanisms underlying the immunologic deficiency. Spleen cells from acutely infected CBA/J mice readily exhibited unresponsiveness to stimulation with concanavalin A, phytohaemagglutinin or a bacterial lipopolysaccharide. However, these cells were unable to reduce the responses that normal syngeneic-mouse spleen cells mounted to these mitogens when cultured together in equal proportions. Furthermore, removal of the Lyt 2.1-bearing cells, known to include the suppressor T cell subpopulation, from infected mouse splenocyte suspensions, did not alter the deficient responsive status of the remaining cells. These results, together with the severe depletion of the T-cell compartment which occurs in the spleens of animals acutely infected with T. cruzi, do not support an important role of suppressor T lymphocytes in the noted deficiency in lymphoid cell reactivity to mitogens. Reduced numbers of responder cells, intrinsic lymphocyte alterations or suppression by cells other than T lymphocytes remain plausible explanations to be explored.     

Immunoregulatory T cells in the peripheral blood of patients with Bechterew''s syndrome.

Seventeen patients with ankylosing spondylitis (Bechterew's syndrome) were investigated. Only 3 of them had detectable autoantibodies, but the IgA and IgM concentrations in serum were increased (p less than 0.05). The patients had a moderate reduction in con-A-induced suppressor cell activity of peripheral blood lymphocytes as detected in con-A/MLC assay, compared with that of 15 controls (41.0 +/- 8.6% suppression compared with 59.4 +/- 5.2%, mean +/-SEM; 0.05 less than p less than 0.1 one-sided test). No differences were found in the percentages of T gamma cells (suppressor cells) and T mu cells (helper cells) between patients an controls. This is to our knowledge the first report of con-A-induced suppressor cell activity an T lymphocyte subpopulations in the peripheral blood of patients with ankylosing spondylitis.     

SUBACUTE THYROIDITIS: ACTIVATED HLA-DR AND INTERFERON-γ EXPRESSING T CYTOTOXIC/SUPPRESSOR CELLS IN THYROID TISSUE AND PERIPHERAL BLOOD

Using a two-colour direct immunofluorescence staining technique, we investigated activated HLA-DR-expressing T helper and T cytotoxic/suppressor cells in peripheral blood of six patients with subacute thyroiditis at referral and at follow-up and in blood from 20 controls. In three of the patients, thyroid fine-needle aspirates were examined as well. At referral, all patients had elevated blood levels of activated T helper and T cytotoxic/suppressor cells 2 (2-4)%, median and range, vs 0 (0-2)%, P less than 0.001 and 12.5 (2-24)%, vs 0 (0-1)% P less than 0.001). At follow-up, the activated proportion of T helper cells had become normal whereas some activated T cytotoxic/suppressor cells remained, 7 (0-8)%. No significant changes in total T cell number were detected when data at referral and at follow-up were compared. In thyroid aspirates, HLA-DR expressing thyrocytes were observed; the total proportion of T cytotoxic/suppressor cells was elevated (70% compared with 35% in blood) and 70% of the T cytotoxic/suppressor cells were HLA-DR+. Furthermore, 55% of the thyroid-infiltrating lymphoid cells were positive for interferon (IFN-gamma+). The finding of activated T cytotoxic/suppressor cells in the blood and thyroid tissue in subacute thyroiditis is consistent with a viral aetiology. Furthermore, intrathyroidal IFN-gamma+ lymphocytes are likely to contribute to expression of major histocompatibility complex (MHC) class II antigens on thyrocytes. No autoantibodies, however, were detected, which suggests that aberrant expression of MHC class II molecules alone is not sufficient to provoke an autoimmune response.     

Phenotypic properties of atypical lymphocytes in cytomegalovirus-induced mononucleosis

The phenotypic properties of the surface of the atypical lymphocytes seen in cytomegalovirus-induced (CMV) mononucleosis were evaluated. Mononuclear cells from peripheral blood were obtained from adult patients within seven to 35 days of the onset of acute CMV mononucleosis. Sheep red blood cell rosetting techniques were used to obtain populations depleted of, or enriched for, T cells. Cell populations were further purified for helper/inducer lymphocytes (T4), cytotoxic/suppressor lymphocytes (T8), or non-T-lymphocytes by monoclonal-antibody binding and by complement-lysis techniques. Cytocentrifuge preparations of the cell fractions were evaluated and atypical lymphocytes were identified by morphological characteristics. The appearance and disappearance of atypical lymphocytes paralleled and antedated the increase and subsequent decrease in T8 cells seen in these patients. A total of 69% +/- 22% of the atypical lymphocytes in the lymphocyte population were of the T8 phenotype, whereas 13% +/- 10% of the atypical lymphocytes were of the T4 phenotype and 18% +/- 13% were non-T lymphocytes. Thus, atypical lymphocytes in CMV mononucleosis reside predominantly, but not exclusively, in the T8 cell population.     

Phenotypic characterization of skin-infiltrating T cells in cutaneous T- cell lymphoma: comparison with benign cutaneous T-cell infiltrates

Using a panel of monoclonal antibodies, we have studied cell surface antigens of infiltrating mononuclear cells in skin biopsies from patients with cutaneous T-cell lymphoma (CTCL) and compared them with the T-cell surface phenotype seen in benign cutaneous T-cell infiltrations (e.g., contact dermatitis, delayed hypersensitivity skin tests, granuloma annulare) and in dermal infiltrates of lymphomatoid granulomatosis patients. We found that unlike circulating CTCL (Sezary) cells, CTCL cells infiltrating skin epidermis frequently expressed the T-cell antigen 3A1. Cutaneous infiltrates in 10 patients with mycosis fungoides (MF) and 1 patient with Sezary syndrome were OKT4 (inducer T cell), OKT8 (suppressor/cytotoxic T cell); 2 patients with MF were OKT4- , OKT8; and one MF patients's skin T cell were OKT4-, OKT8+. Similar to CTCL infiltrating cells, most of the benign skin T-cell infiltrates were usually 3A1+. OKT4+, and OKT8-. Our study shows the complex nature of T-cell antigen patterns in inflammatory and malignant skin T-cell infiltrations. We demonstrated that the CTCL the skin epidermal infiltrating T-cell phenotype is not invariate, and in many cases, is similar to the phenotype of clinically benign cutaneous T-cell infiltrations.     

The effects of cigarette smoking on T cell subsets. A population-based survey of healthy caucasians

To investigate the influence of cigarette smoking on mononuclear cell subsets, we determined T cell, B cell, monocyte, and HLA-DR+ subsets in a population-based, stratified, random sample of healthy Caucasians using monoclonal antibodies and flow cytometry. The study population consisted of 282 subjects 20 to 69 yr of age, including 108 smokers and 174 nonsmokers. Multivariate analysis techniques were used to assess the influence of cigarette smoking status after controlling for the effects of age and gender. Cigarette smoking was associated with a nonspecific increase in the leukocyte count involving all major cell types (smokers: 8.50 +/- 0.15 versus nonsmokers: 7.33 +/- 0.12 cells/mm3; p less than or equal to 0.0001). In addition, cigarette smokers had a selective increase in CD4+ cells (helper-inducer T cells) compared with nonsmokers (55.3 +/- 0.8 versus 52.2 +/- 0.6% of lymphoid cells; p = 0.002), resulting in a statistically significant increase in the CD4+/CD8+ (helper/suppressor) ratio (2.42 +/- 0.1 versus 2.13 +/- 0.16; p = 0.02). There was no significant difference between smokers and nonsmokers in the level of CD3+ cells (total T cells: 76.8 +/- 0.7 versus 76.1 +/- 0.5; p = 0.5), CD8+ cells (suppressor-cytotoxic T cells: 25.7 +/- 0.8 versus 27.0 +/- 0.5%; p = 0.1), CD19+ cells (B cells) (10.7 +/- 0.4 versus 10.0 +/- 0.3%; p = 0.2), CD14+ cells (monocytes) (18.0 +/- 0.6 versus 17.0 +/- 0.4%; p = 0.2), or HLA-DR+ cells (14.5 +/- 0.5 versus 14.0 +/- 0.4%; p = 0.4).(ABSTRACT TRUNCATED AT 250 WORDS)     

Abnormal immunoregulation in remission Hodgkin disease

Peripheral blood mononuclear cells from 11 patients with remission Hodgkin disease and 20 normal controls were incubated with irradiated allogeneic lymphocytes in one-way mixed lymphocyte cultures. Simultaneously, modified assays were performed by adding supplemental irradiated PBM, T lymphocytes, or adherent cells autologous to the responders. Baseline allogeneic responsiveness of patients and controls was not different. However, significant suppression (p less than .01) was demonstrated when the cultures were supplemented with patient mononuclear cells or adherent cells, an effect not found with similar supplemental cells from controls. Conversely, T-cell supplementation of control cultures produced more than twofold increases in proliferation but significantly less augmentation in the patients' cultures (p less than .01). T-cell subset analysis in six patients showed decreased helper: suppressor cell ratios. Hodgkin disease patients have adherent suppressor cells, which persist during remission, as well as a defect in T-cell helper function.     

Microsomal antigen-reactive lymphocyte lines and clones derived from thyroid tissue of patients with Graves' disease

Thyroid mononuclear cells (TMC) were maintained in long term cocultures with thyroid fibroblasts and thyroid epithelial cells from patients with Graves' disease, using medium supplemented with thyroid microsomal antigen (McAg) and IL-2. The TMC consisted predominantly of T4+ (CD4+, helper) and, to a lesser extent, T8+ (CD8+, cytotoxic/suppressor) lymphocytes, with a small number of macrophages and natural killer cells. The average T4+ to T8+ ratio was 3.2. From these cultures we obtained thyroid T cell lines and clones reactive to thyroid antigens. T Cell lines were tested in a microproliferation assay using thyroglobulin (Tg), McAg, tetanus toxoid, and IL-2. Of 14 lines from 6 patients, 2 proliferated in response to McAg when TMC plus thyroid fibroblasts were used as antigen-presenting cells. Clones of thyroid lymphocytes were obtained by culturing cells at limiting dilution with IL-2, McAg, and different types of autologous accessory cells. Peripheral blood mononuclear cells plus skin fibroblasts provided the best source of accessory cells, allowing near 100% cloning efficiency. Of 26 clones tested, 6 recognized McAg, 2 were Tg reactive, and 3 were autoreactive. All phenotyped clones were of the T4+ phenotype. Our method results in production of thyroid T cell lines and clones. The fibroblasts probably provided growth factors and/or collaborated with peripheral blood mononuclear cells as antigen-presenting cells. These lines and clones from patients with Graves' disease were predominantly helper T cells, in contrast to the previously demonstrated cytotoxic/suppressor cell predominance in cells from patients with Hashimoto's thyroiditis. This difference in cell function may help explain the differing clinical courses of these two closely related autoimmune thyroid diseases. The availability of long term microsomal antigen-specific T cell clones should allow careful analysis of the role these cells play in thyroid autoimmunity.     

The generation of human natural killer cells from CD34+/DR- primitive progenitors in long-term bone marrow culture

We have adapted the stroma-dependent long-term bone marrow culture (LTBMC) system to study the development of human natural killer cells (NK) from the CD34+/HLA-DR- (CD34+/DR-) BM mononuclear cell (BMMNC) population. The CD34+/DR- population does not express any known antigens associated with myeloid or lymphoid lineage and has been shown by us and others to contain primitive hematopoietic progenitors capable of both self-renewal and differentiation to myeloid lineage. CD34+/DR- cells obtained from normal human BM by fluorescence-activated cell sorting were plated on allogeneic, irradiated BM stromal layers. After 5 weeks of culture in the presence of media containing recombinant interleukin-2 and human serum, 147- +/- 21-fold expansion of cells with the morphologic appearance of large granular lymphocytes was observed. Cultured cells (84.8% +/- 1.5%) expressed the characteristic CD56+/CD3- phenotype of NK. A proportion of CD56+/CD3- cells expressed other markers of lymphoid lineage that have been associated with mature NK, including CD2 (7.8% +/- 1.2%), CD7 (19.5% +/- 2.8), CD8 (3.1% +/- 1.0%), and CD16 (4.5% +/- 1.3%). The cultured cells did not express other antigens associated with T-lymphocyte (CD3, CD5, T-cell receptor [TCR] alpha/beta and TCR gamma/delta), B-lymphocyte (CD19), myeloid (MY8, CD33, and CD71), or monocytoid (CD14 and CD15) lineage and did not express the CD34 antigen associated with hematopoietic progenitors present on the starting population. This NK population was cytotoxic against both K562 (E:T 20:1; 79% +/- 1.9%) and Raji (E:T 20:1; 38% +/- 5.7%) target cell lines. The NK progenitor frequency in the CD34+/DR- cell population determined by limiting dilution of CD34+DR- on stromal layers followed by a functional chromium release assay against K562 targets was 1:169 +/- 50 CD34+/DR- cells. The data suggest that human LTBMC developed to study myeloid differentiation can be modified to study the origin and development of the NK and possibly other lymphoid lineages. Modified cultures show that cells with morphologic, phenotypic, and functional characteristics of NK can be derived from a population of BMMNC with the phenotype of primitive hematopoietic progenitors and without phenotypic evidence of lymphoid- or myeloid- lineage commitment. Further studies will address the cell of origin and the ontogeny of human NK and other lymphoid lineages.     

Tissue distribution of lymphocytes in rheumatic heart valves as defined by monoclonal anti-T cell antibodies

Fresh cardiac valvular tissues and atrial appendages removed from 106 Indian patients with rheumatic heart disease at the time of corrective cardiac surgery were examined to determine the characteristics of valvular interstitial lymphocytic infiltrates using conventional histologic staining along with indirect immunofluorescent techniques. Precise identification of the phenotypic profiles of inflammatory mononuclear cells was attempted using anti-IgG, anti-Ia, and monoclonal mouse hybridoma reagents identifying T cells (OKT3) as well as T cell subsets (OKT4 helper/inducer and OKT8 suppressor/cytotoxic cells). A similar group of 21 patients undergoing cardiac valvular resection in Albuquerque was studied. The mean age of Indian patients providing valve tissues was 27.7, whereas in those in Albuquerque, it was 52 years. Twenty-five percent of rheumatic heart valves in Indian patients showed significant interstitial lymphoid infiltrates, and one third of the rheumatic valves from patients in Albuquerque showed similar mononuclear cell collections. Lymphoid infiltrates contained a predominance of T cells (70 to 80 percent) and only occasional B cells. Most of the T cells were OKT4-positive, with only a minor representation of suppressor/cytotoxic OKT8-positive T cells. In many instances, OKT4-positive helper T cell collections were closely juxtaposed to fibroblasts and collagen fibrils. These findings suggest that the chronic rheumatic scarring process may involve helper/inducer T cells as an ancillary factor in the indolent contracture and fibrosis of deformed cardiac valvular structures. Attempts to demonstrate residual streptococcal antigens by indirect immunofluorescence using a wide panel of heterologous rabbit F(ab')2 reagents with specificity for group A streptococcal membranes, cell wall mucopeptide, or group A carbohydrate gave negative results.