Suppressor cell activity in peripheral blood in cancer patients after surgery.

The influence of operative trauma on the responsiveness of PBM to PHA and Con A and the level of Con A-induced suppressor cell (Con A-SC) activity toward autologous responder cells (RC) were examined in patients with stage 0 uterine cancer after hysterectomy. The operation brought about a decrease on the second post-operative day in the responsiveness of PBM to various concentrations of PHA by 19.2-28.8% and to Con A by 31.2-41.8%, concomitantly with a decline in Con A-SC activity from 43.7 to 22.0%. When the Con A-SC were tested against RC obtained from blood samples drawn prior to surgery and stored at -196 degrees C, an increase in the post-operative SC activity from 41.6 to 52.2% was observed which might indicate a post-operative stimulation of SC. On the other hand, when Con A-SC were raised from PBM drawn before surgery and tested against RC obtained post-operatively, they displayed a decreasing suppressive activity from 27.2 to 2.7%. This might be due to the pre- and post-operative stimulation of RC. The observed changes were most likely caused by a transient decrease in the number of blood T lymphocytes, altered proportions of blood T cells to other PBM cells and probably a non-specific stimulation of autologous cells responding in the suppressor cell activity assay.     

Suppressor response in lepromatous leprosy patients: role of Leu 2a cells.

The contribution of non-specific suppressor mechanisms to the overall immunoregulatory defect observed in lepromatous leprosy was evaluated. Con A-induced suppression was assayed using the standard two-stage test in 27 lepromatous leprosy patients, 19 of them during the quiescent stage (LL) and eight during erythema nodosum lepromatosum (ENL). Lymphocytes from normal individuals react in this assay, yielding higher suppression as the numbers of Con A-induced suppressor cells (Leu 2a+ cells) increase. In contrast, two patterns of response were observed in both LL and ENL patients: those giving lower suppression as the number of suppressor cells increased (LL-A and ENL-A) and those responding with the normal pattern (LL-B and ENL-B). The abnormal dose-response profile was not related to the disease stage, as both ENL and LL patients were included in groups with normal or atypical response. Reaction of the potential suppressor cells with anti-Leu 2a antibody abolished suppression in LL-B and normals, whereas Con A-induced suppression was unchanged or higher in ENL-A, ENL-B and LL-A, indicating that in these patients Leu 2a+ cells interfered with the generation of Con A-induced suppression. The contribution of spontaneous suppression was examined and it was shown that suppressor activity in the absence of Con A stimulus was higher in ENL (both ENL-A and ENL-B) and LL-A. Thus, it appears that the occurrence of high spontaneous suppressor activity, probably related to in vivo activation, is associated with a relative inability to generate de novo suppression after Con A stimulation in these patients.     

Suppressor cell activity in viral and non-viral chronic active hepatitis.

Suppressor cell function was studied in twenty-nine patients with chronic active hepatitis (CAH) in relation to possible aetiological causes and activity of liver disease. All fifteen patients with evidence of viral aetiology (ten HBsAg-positive CAH and five non-A, non-B CAH) showed normal suppressor cell function independently of severity of liver damage. In contrast, fourteen patients with HBsAg-negative CAH, including four cases with circulating antibodies to the hepatitis B virus, demonstrated a significant reduction in supprpessor cell activity compared to control subjects. No significant difference was found in this group between cases with and without circulating autoantibodies. In four out of five HBsAg-negative patients tested serially suppressor cell defect correlated with disease activity suggesting an abnormality in the regulation rather than a depletion of suppressor cells. These results suggest that different mechanisms are responsible for autoimmunity to the liver in virus and non-virus-related CAH.     

Suppressor activity of blood lymphocytes from guinea-pigs treated with ALS

PHA-induced transformation of guinea-pig lymphocytes was profoundly inhibited by the injection of antilymphocyte serum (ALS). This effect, seen 24 h after ALS administration, disappeared within 3 days. Lymphocytes of animals injected with ALS 24 h earlier inhibited the blast transformation of autologous normal lymphocytes. The supernatants of short term cultures of such cells, even after pre-treatment with puromycin, exhibited the same inhibitory activity. It is suggested that the immunosuppressive effect of ALS is not limited to its direct action on lymphocytes.     

Increased chitotriosidase activity in serum of leprosy patients: Association with bacillary leprosy

Human phagocyte-specific chitotriosidase is associated with several diseases involving macrophage activation. Since macrophage activation plays an important role in the control of Mycobacterium leprae infection, we studied the association of chitotriosidase with leprosy both in serum and in situ in lesional skin biopsies from patients. Serum samples from 78 Indonesian leprosy patients (39 non-reactional and 39 reactional leprosy patients) and 36 healthy controls (HC) from the same endemic region were investigated. The patients were classified as multibacillary (MB, n = 69) or paucibacillary (PB, n = 9) based on the bacterial index in slit-skin smears. Thirty-six of the reactional patients had erythema nodosum leprosum (ENL), while only 3 had reversal reaction (RR). Follow-up serum samples after corticosteroid treatment were also obtained from 17 patients with ENL and one with RR. Multibacillary (MB) patients showed increased chitotriosidase activity in serum as compared to paucibacillary (PB) patients and healthy controls. Although no significant difference was observed between reactional and the corresponding non-reactional groups, ENL showed significantly higher chitotriosidase activity as compared to HC. Furthermore, corticosteroid treatment resulted in significant decline of enzyme activity in ENL sera. Chitotriosidase activity correlated with levels of neopterin, another macrophage activation marker, but not with IL-6, IFN-γ, TNF-α and IL-10. Immunohistochemical staining of 6 MB (LL = 5, BL = 1) lesional skin sections from stored material showed positive staining for chitotriosidase within lipid-laden macrophages suggesting that macrophages are the source of the enzyme detected in serum. Thus, serum chitotriosidase activity is potentially useful in distinguishing MB from PB leprosy and in monitoring response to therapy in ENL.     

Differences in predominant T cell phenotypes and distribution pattern in reactional lesions of tuberculoid and lepromatous leprosy.

The nature and histological pattern of the cutaneous infiltrates of 17 leprosy patients in reversal reactions (Type I) and erythema nodosum leprosum (Type II, ENL) were compared with tissues from 18 non-reactional borderline leprosy (BT, BL) and lepromatous leprosy (LL) patients using monoclonal antibodies and immunofluorescence. Reactional BT lesions showed a mild increase in OKT11+ pan T cells as compared to non-reactional tissues and a significant influx of OKT8+ (suppressor/cytotoxic) cells which were peripherally localized in the lymphocyte mantle surrounding the epithelioid cells. The Leu 3a+ (helper/inducer) cells were scattered amongst the lymphocytes and macrophages. The mean ratio (+/- s.d.) of Leu 3a+/OKT8+ cells was 1.88 +/- 0.64 in Type I BT reactions as compared to 2.95 +/- 0.95 in BT lesions. In contrast, lesions of BL reversal reactions and ENL showed a more marked increase in pan T cells with a preponderance of the helper/inducer subset, Leu 3a+/OKT8+ ratio being 2.26 +/- 0.61 and 0.93 +/- 0.57 in BL reactional and non-reactional lesions, respectively. Interestingly, this increase in the numbers of the T cells reached levels observed in BT lesions. The distribution pattern of OKT8+ cells was similar to Leu 3a+, both being diffusely scattered amongst the bacilli laden macrophages. Ia like antigens were present in all granulomas and were abundant on lymphocytes and macrophages and less conspicuous on epithelioid cells. T6+ Langerhans cells were uniformly increased in all reactional lesions. It would appear that the changes observed in both Type I and Type II reactions are similar in the lepromatous group of patients. They differ significantly from the BT reversal reaction in terms of the dominant T cell subset and the microanatomical distribution of the OKT8+ cells in the lesions.     

Defective intralesional interferon-gamma activity in patients with lepromatous leprosy

Cryostat sections of full-thickness skin biopsies from 21 patients along the whole spectrum of leprosy were subjected to immunohistological examination with special regard to defective lymphokine production. There was an inverse relationship between intra-lesional IL-1 reactivity and IL-2R expression, in that the latter was markedly observed in tuberculoid lesions. Whenever epithelioid cell containing granulomas were present in paucibacillary forms, significant reactivity within the central phagocytic cells with the monoclonal antibody directed against interferon-gamma was detectable. The keratinocytes covering tuberculoid lesions abundantly expressed class II alloantigens (HLA-DR antigens), indicating high intra-lesional interferon-gamma activity. In contrast, multibacillary forms revealed significant anti-IL-1 reactivity within the cellular infiltrate. IL-2R bearing cells were virtually absent as was anti-HLA-DR reactivity of the keratinocytes, underlining a defective intra-lesional interferon-gamma activity.     

Suppressor cell activity of human alveolar macrophages in interstitial lung diseases.

It has been shown that alveolar macrophages (AM) are able to modulate lymphocyte proliferation in vitro. The purpose of this study was to evaluate the effect of AM on the proliferation of autologous peripheral lymphocytes (APL) in patients with interstitial lung disease (ILD) compared to controls. Thirty patients were investigated: eight with idiopathic pulmonary fibrosis (IPF), nine with sarcoidosis(SA), seven with rheumatoid arthritis (RA) and six controls (CO). AM and APL were co-cultured at an increasing macrophage/lymphocyte ratio: 1%, 10%, 20% and 50%. A dose-dependent effect was observed and related to the number of AM added to APL, enhancing at low ratios and suppressing at high ratios. Suppression of proliferation by 50% AM differed in the four groups tested: 94.6% (92-98) in IPF, 73.0% (49-100) in SA, 43% (25-57) in RA, 32.4% (22-41) in the CO (P less than 0.01, P less than 0.05, and P0.05 respectively, compared to CO). Suppressive cell activity of AM from patients with ILD was higher than suppressive cell activity of the CO group. Suppression with 10% of AM in ILD group was 18% (2.2-62) compared with 2.58% (-13-17) in the CO group (P less than 0.05). 20% AM in ILD group showed 35% (3-76) suppression in comparison with 9.76% (-11-27) in the control group (P less than 0.01), 50% AM in ILD have a suppressive activity of 71% (25-100) in contrast to 32.4% (22-41) in control (P less than 0.01). In conclusion, AM from patients with interstitial lung diseases have a significantly stronger suppressive effect on the proliferation of autologous peripheral lymphocytes than controls. This is a new aspect of the study of activation of AM in these kinds of disorders.     

Increased multiclonal antibody-forming cell activity in the peripheral blood of patients with SLE

21 patients with criteria for systemic lupus erythematosus (SLE) and 12 normal controls were studied for their spontaneous circulating IgM and IgG plaque-forming cells (PFCs) reactive against sheep erythrocytes (SRBC) and against a panel of five haptens. Quantitatively defined active and mildly active SLE patients had significantly elevated IgM- and IgG-producing PFCs in their peripheral blood reactive with the panel of five chemically defined haptens. Those patients having inactive SLE also showed increased circulating IgM PFCs. Significant elevations in circulating hapten-reactive PFCs were found to correlate progressively with disease activity in the inactive, mildly active, and active SLE patient groups. Circulating IgM- and IgG-secreting PFC reactive against SRBC were both significantly elevated only in those patients with active SLE. The data support the concept that SLE patients have a generalized increase in B cell activity against a broad repertoire of determinants, even those ostensibly unrelated to natural tissue antigens.     

Spontaneous suppressor cell activity in the peripheral blood of patients with malignant and chronic inflammatory bowel diseases.

Fifteen patients with colorectal tumours, 15 patients with Crohn's disease (CD) and two groups of normal controls were investigated for the presence of spontaneous suppressor cell activity (SSCA) in peripheral blood mononuclear cells (PBMC). In comparison to the age and sex matched controls patients with colorectal carcinoma exhibited a significant increase in SSCA (P less than 0.01). No evidence could be obtained that the suppressive effect was due to a soluble factor such as prostaglandins. In contrast, patients suffering from CD presented a decreased SSCA. No correlation was obtained between the enhanced SSCA in tumour patients and the clinical stage of the disease, levels of oncofetal antigens or serum immune complexes. Likewise in patients with CD no correlation was found between decreased SSCA and CD index or different serum parameters. When PBMC of the different test groups were incubated with histamine or cimetidine before they were added to the indicator system the suppressive activity remained unchanged. Also pre-incubation of normal PBMC with alpha-fetoprotein or carcinoembryonic antigen did not change the spontaneous suppressor cell activity. Whether the significantly enhanced in vivo activity of spontaneous suppressor cells in patients with colorectal carcinoma is one of the multifactorial mechanisms leading to the establishment of cancer or whether it rather represents a reflection of the immune system on colorectal tumour antigens remains unsolved.     

Suppressor cell responses in patients with rheumatoid arthritis: the effect of thymosin

Peripheral blood lymphocytes (PBL) from patients with rheumatoid arthritis (RA) and age and sex-matched normal controls were compared in a Concanavalin A (Con A)-induced suppressor cell assay. Suppression induced by pre-incubation with Con A was significantly greater in PBL from RA patients than in PBL from normal controls. Preincubation with thymosin fraction 5, in the absence of Con A, also induced greater suppressor cell activity in PBL from normal controls. Preincubation with Con A and thymosin, simultaneously, induced suppression similar to that seen with Con A alone. These results suggest the presence of an immunoregulatory defect in RA, characterized by an excess of both Con A and thymosin-inducible suppressor cells, that may play a role in disease pathogenesis. The implications of these observations for immunotherapy of rheumatoid arthritis with thymosin are discussed.     

Effect of tuftsin stimulation on the microbicidal activity exerted by blood monocyte-macrophages of leprosy patients

The ability of blood monocyte/macrophages from normal donors, tuberculoid leprosy (BT/TT) and lepromatous leprosy (BL/LL) patients to exert enhanced microbicidal activity was assayed after stimulating with 0.8 microM tuftsin, as a function of the duration of cultures in vitro. Normal and BT/TT macrophage cultures showed a statistically significant increase in microbicidal activity against Staphylococcus aureus at all ages of culture (6 h to 14 days), though the overall magnitude of the enhancement shows a decrease with increasing culture age in the same populations. However, 14-day old BL/LL macrophage cultures were unable to undergo tuftsin-mediated stimulation of microbicidal activity against S. aureus and even, fresh 6 h-old cultures exhibited a tuftsin-stimulated response profile similar to 14-day old normal and BT/TT cultures. Also, 7 and 14-day cultures of normal, BT/TT and BL/LL macrophages were unable to inhibit/kill intracellular Mycobacterium leprae after a single stimulation with 0.8 microM tuftsin. However, serial, daily stimulation with 0.8 microM tuftsin resulted in 77-140% inhibition of 3H-thymidine uptake by the 12th day of cultures in vitro in the three groups. These results suggest that BL/LL macrophages exhibit a premature inability to undergo tuftsin stimulated microbicidal activity, which may possibly be reversed by serial dosage of tuftsin.     

Use of a whole blood assay to evaluate in vitro T cell responses to new leprosy skin test antigens in leprosy patients and healthy subjects.

Development of an immunological tool to detect infection with Mycobacterium leprae would greatly benefit leprosy control programmes, as demonstrated by the contribution of the tuberculin test to tuberculosis control. In a new approach to develop a 'tuberculin-like' reagent for use in leprosy, two new fractions of M. leprae depleted of cross-reactive and immunomodulatory lipids- MLSA-LAM (cytosol-derived) and MLCwA (cell wall-derived)-have been produced in a form suitable for use as skin test reagents. T cell responses (interferon-gamma (IFN-gamma) and lymphoproliferation) to these two new fractions were evaluated in a leprosy-endemic area of Nepal using a simple in vitro whole blood test. The two fractions were shown to be highly potent T cell antigens in subjects exposed to M. leprae-paucibacillary leprosy patients and household contacts. Responses to the fractions decreased towards the lepromatous pole of leprosy. Endemic control subjects also showed high responses to the fractions, indicating high exposure to M. leprae, or cross-reactive mycobacterial antigens, in this Nepali population. The new fractions, depleted of lipids and lipoarabinomannan (LAM) gave enhanced responses compared with a standard M. leprae sonicate. The cell wall fraction appeared a more potent antigen than the cytosol fraction, which may be due to the predominance of the 65-kD GroEL antigen in the cell wall. The whole blood assay proved a robust field tool and a useful way of evaluating such reagents prior to clinical trials.