Lymphocyte Transformation Responses Research Articles

The impact of diabetes on COVID‐19 infection

The impact of diabetes on <scp>COVID</scp>‐19 infection

Immunologic studies of patients with histoplasmosis.

Immunologic responses of patients with active histoplasmosis (Group I) were compared to the responses of healthy persons with positive histoplasmin skin-test reactions (Group II), and to those of healthy persons with negative histoplasmin skin-test reactions (Group III). Cellular immune responses were significantly depressed in patients. Seven (54 per cent) of 13 patients failed to respond to histoplasmin skin testing, and two (15 per cent) failed to respond to skin-test antigens unrelated to Histoplasma capsulatum. Lymphocyte transformation (LT) responses of patients were severely depressed in vitro (p less than 0.001) to Histoplasma antigens when compared to the responses of healthy, histoplasmin-reactive donors. Transformation responses to Candida antigen were not impaired in the patient population. Culturing lymphocytes of patients in serum obtained from healthy donors as opposed to autologous serum resulted in a significant (p less than 0.05) increase in LT responses to H. capsulatum. Responses to Candida antigen and to mitogens were not affected by the serum source. Serum-mediated suppression of LT responses correlated (p less than 0.01) with complement-fixing antibody titers to Histoplasma yeast-phase antigen and suggests that antibody, either alone or complexed with antigen, may suppress T-cell response in vitro in this disease.

Altered immune responses in patients with chronic mucocutaneous candidiasis

The purpose of this study was to investigate the lymphocyte transformation responses and cytokine secretion of peripheral blood mononuclear cells (PBMC) from patients with chronic mucocutaneous candidiasis (CMC). Phytohaemagglutinin (PHA) mitogen and Candida albicans (C. albicans) antigen proliferation assays were performed by culturing PBMCs in RPMI 1640. The levels of interleukin (IL)-2, IL-10, IL-17 and interferon (IFN)-γ present in the supernatant of cultures were determined using enzyme-linked immunosorbent assay (ELISA). The results showed that most patients (92.3%) had a low proliferative response to C. albicans antigens and PHA. PBMCs from CMC patients produced lower levels of T (h)-1 cytokines IL-2 (78.5±59.8 pg/mL) and IFN-γ (115.1±43.3 pg/mL) in response to Candida antigens when compared to controls (Il-2: 177±103.6 pg/mL; IFN-γ: 330.3±21.6 pg/mL) (P<0.05). Conversely, we observed a partial enhancement of IL-10 in the patients (213.7±86.1 pg/mL). Production of IL-17 indicated no significant differences between patients and controls when stimulated by Candida antigens (21.5±8.6 pg/mL versus 32.4±12.2 pg/mL) and PHA (27.7±11.5 pg/mL versus 36.2±9.1 pg/mL), respectively. These findings suggest that Candida antigens trigger a Th2 instead of Th1 cytokine response in patients with CMC. For better understanding, further studies require on a larger number of patients into the future.

Immunological aspects of cystic echinococcosis in Erbil

Background and objectives: Echinococcus granulosus exists as a complex of different strains that differ in a wide variety of criteria that impact on the epidemiology, immunology, pathology and control of hydatid disease. This study was undertaken to investigate both humoral and cellular immune responses that are developed against hydatid cysts in Erbil. Methods: Thirty patients (9 males and 21 female) with surgically confirmed cystic echinococcosis and 10 apparently healthy individuals were included in this study. IgG ELISA was performed to asses humoral immune responses. CD4/ CD8 ratio, eosinophil count and lymphocyte transformation response were done to asses the cellular immune responses. The level of IFN-γ and TNF-α was also assayed. Results: The sensitivity of ELISA to detect anti-hydatid antibodies was shown to be 83.33%. CD4 / CD8 ratio was significantly (P&lt; 0.001) decreased in patients with cystic echinococcosis as compared to normal control group, while eosinophil count (P&lt; 0.001), lymphocyte transformation response (P&lt; 0.001) and IFN-γ level (P&lt; 0.01) were significantly increased. In contrast the level of TNFα was non- significantly changed in echinococcosis patients. Conclusion: The current study showed that the local strain of Echinococcus granulosus induces both cellular and humoral immune responses, and the number of peripheral blood CD8 T cells was significantly increased in cystic echinococcosis patients. However, hyporesponsivness to hydatid specific antigens has not been induced.

In vivo and in vitro boosting effects of tuberculin skin tests in guinea-pigs immunized with living BCG or with killed Mycobacterium tuberculosis.

Eight weeks after the onset of immunization with living BCG vaccine or with heat-killed, dried Mycobacterium tuberculosis in paraffin oil (TB), guinea-pigs were skin tested with small doses of tuberculin PPD. Three weeks later the effect of these tests on skin reactions and on lymphocyte transformation (LT) responses of lymph node lymphocytes (LNL) or peripheral blood lymphocytes (PBL) was estimated by a comparison with non-tested groups. For both immunogens, the skin test after 8 weeks significantly enhanced skin reactions, particularly to low tuberculin doses. In the BCG-vaccinated guinea-pigs the LT responses of both cell types were significantly enhanced by the skin test after 8 weeks, whereas the LT responses from the TB-immunized guinea-pigs were not affected. Therefore, in the planning and interpretation of in vitro tests of cellular immunity, possible effects from previously applied skin tests should be taken into consideration.

Cell-mediated immunity in acute idiopathic optic neuritis and multiple sclerosis.

Lymphocyte transformation responses to phytohaemagglutinin, measles antigen and tuberculin and the absolute numbers of circulating T and SIg+ cells were determined in 16 patients with acute idiopathic optic neuritis (ON), 42 patients with multiple sclerosis (MS) and 78 healthy controls. Patients with acute ON showed impaired lymphocyte transformation responses in both autologous plasma and AB serum similar in extent to those seen in MS patients in relapse. They were not associated with a reduced total number of circulating T cells.

Oral vaccination of mice with lipid-encapsulated Mycobacterium bovis BCG: Effect of reducing or eliminating BCG load on cell-mediated immunity

Oral delivery of lipid-encapsulated BCG represents an effective method for vaccination against tuberculosis (Tb). This method establishes live, replicating BCG in the lymphatic tissues of the alimentary tract, and promotes systemic-level cell-mediated immunity (CMI) and consequent protection against virulent mycobacterial challenge. Here, we investigated the effects of reducing or eliminating the BCG load on CMI responses in mice. Mice receiving a standard immunising dose of approximately 10 7 BCG (range, 1–5 × 10 7) developed mycobacterial antigen-specific lymphocyte transformation (LT) responses, as well as interleukin-2 (IL-2) and gamma-interferon (IFN-γ) secretion, at 8 and 18 weeks post-oral vaccination. These responses were concurrent with establishment of viable, replicating BCG in the alimentary tract lymphatics in over 90% of cases. Reducing the immunising dose by 10-fold reduced the magnitude of CMI, concurrent with abridged establishment of BCG in the lymphatics; reducing the dose 100-fold ablated BCG establishment, and diminished the production of IFN-γ by antigen-stimulated lymphocytes of these mice. In mice immunised using the standard dose, replicating BCG were eliminated from the alimentary tract lymphatics using selective antibiotics. Interestingly, while lymphocyte transformation and interleukin-2 responses remained largely unaltered in these mice, levels of IFN-γ produced by antigen-stimulated lymphocytes were shown to be reduced significantly. This study identifies a dosage threshold for effective oral vaccination using lipid-encapsulated BCG, and furthermore highlights the requirement of on-going intra-lymphatic BCG replication for the maintenance of strong IFN-γ production, above other indicator CMI responses.

Cell-mediated and humoral immune responses to a virulent plasmid-cured mutant strain of Salmonella enterica serotype gallinarum in broiler chickens

One-week-old Salmonella-free broiler chicks were subcutaneously immunized and subsequently boosted two weeks later with 2 × 10 7 cfu 0.5 ml −1 of an 85-kb virulent plasmid-cured spectinomycin-resistant mutant strain (SG9VP -Spc r) of Salmonella gallinarum 9 ( S. enterica serotype gallinarum 9) along with a control group of mock-immunized chickens. The chicks were subcutaneously challenged at 5 weeks of age with 5 × 10 10 cfu 0.5 ml −1 (5 × LD 50) of wild-type S. gallinarum var. Duisburg ( S. enterica serotype gallinarum var. Duisburg). The cellular and humoral immune responses were measured at weekly intervals post-immunization (PI) and post-challenge (PC) using lymphocyte stimulation test (LST), delayed type hypersensitivity (DTH) test, serum tube agglutination test (STAT) and enzyme-linked immunosorbent assay (ELISA). High stimulation indices suggestive of a potent lymphocyte transformation response and high persistent serum IgG titres were recorded in immunized chickens at the termination of the experiment. These findings indicate that the live attenuated mutant vaccine induced a strong cellular and humoral immunity, which may play a role in the protection of fowl typhoid in broiler chickens.

Immune responses against excreted/secreted antigens of Toxoplasma gondii tachyzoites in the murine model.

In the present study, excretory secretory antigens (ESA) of Toxoplasma gondii were evaluated in immunization of 8-10 week inbred female Balb/c mice. Tachyzoites of the parasite were cultured in cell-free incubation medium (RPMI-1640), and then supernatant of the medium was loaded on an ion-exchange chromatography column. Two fractions (ESA-F(1) and ESA-F(2)) were collected from the column. For immunization of the mice, 50 were allocated into 5 groups of 10. The first, second, third, and fourth groups were immunized, twice with total-ESA, ESA-F(1), ESA-F(2) or toxoplasma lysate antigen (TLA), respectively. The fifth group was selected as a negative control group (non-immunized). The virulent RH strain of Toxoplasma gondii was used to challenge. Delayed-type hypersensitivity responses (DTHs) were measured by intra-footpad injection measuring induration at timed intervals. Lymphocyte transformation tests (LTTs) were done on lymph node cells using [3H] thymidine incorporation as an indication of reactivity. Peritoneal macrophages from sensitized mice were stimulated and nitric oxide was measured by Griess method. The ESA-F(1) and ESA-F(2) fractions were separated on poly acrylamide gel electrophoresis (PAGE) and SDS-PAGE. ESA-F(1) had 4 bands on PAGE and 14 bands on SDS-PAGE. ESA-F(2) had one band on PAGE and two bands on SDS-PGE. Sensitized mice showed DTH and lymphocyte transformation responses to total-ESA, ESA-F(1), and ESA-F(2) and peritoneal macrophages produce nitric oxide following stimulation. In challenge experiments, all non-immunized mice died within 10 days, whereas immunized mice survived for longer time periods (P<0.05). The highest survival rate was observed in mice that immunized with ESA-F(2). We suggest that these antigens especially ESA-F(2) should be of value for the development of new strategies for immunization against toxoplasmosis.

The tuberculin skin test in relation to immunological in vitro reactions in BCG-vaccinated healthcare workers.

The aim was to study the tuberculin skin test in relation to immunological in vitro reactions in bacille Calmette-Guerin (BCG)-vaccinated healthcare workers. The present study was performed in Sweden, a country with a low incidence of tuberculosis, a high BCG vaccination efficacy and high tuberculin conversion rates. BCG-vaccinated healthcare workers (n=381) were tuberculin skin tested. From these, 11 subjects with negative tuberculin reactions (<6 mm) were matched for age and sex with 11 subjects with large positive reactions (> or = 15 mm). Lymphocyte transformation and the production of interferon-gamma (IFN-gamma) were analysed after stimulation in vitro of peripheral blood mononuclear cells with tuberculin purified protein derivative, heat-killed tubercle bacilli and a culture filtrate from tubercle bacilli. In the tuberculin-positive group the lymphocyte transformation response was 2-3 times larger, and IFN-gamma production was 7-10 times larger, than in the tuberculin-negative group (p<0.001). The present results suggest that a positive tuberculin skin test in bacille Calmette-Guerin-vaccinated subjects indicates a stronger immune response of the protective T-helper 1-type than does a negative test. In similar settings, the study supports the traditional practice of regarding the tuberculin skin test in bacille Calmette-Guerin-vaccinated subjects as an indicator of a protective immune response against tuberculosis.

Common variable immunodeficiency in miniature dachshunds affected with Pneumonocystis carinii pneumonia.

Seven miniature dachshunds, all under the age of 1 year, were presented with polypnea, tachypnea, and exercise intolerance as a result of Pneumocystis carinii pneumonia, which was diagnosed on transtracheal aspirate cytology. In all of the dogs, historical and clinical signs were suggestive of immune incompetence. Immunological studies undertaken were leukogram parameters, serum immunoglobulin fraction quantification, lymphocyte transformation assay. CD3 and CD79a lymphocyte markers on lymphoid tissue, and anti-canine immunoglobulin G immunoperoxidase staining. The immunological studies showed hypogammaglobulinemia, deficiency of serum immunoglobulins A, G, and M, decreased lymphocyte transformation response to phytohemagglutinin and pokeweed mitogens and absence of B lymphocytes with presence of T lymphocytes in the lymphoid tissue stained with CD3 and CD79a lymphocyte markers. The preceding findings suggest that P. carinii pneumonia occurring in the miniature dachshund is a result of both a T- and B-cell deficiency. This presentation is not the classic primary severe combined immunodeficiency syndrome but rather combined variable immunodeficiency, which has been well documented in humans but never in the dog.

Cell-mediated immunity to Malassezia furfur in patients with seborrhoeic dermatitis and pityriasis versicolor.

The lymphocyte transformation response to Malassezia furfur, Candida albicans, phytohaemagglutinin, concanavlin A and tuberculin purified protein derivative of 12 patients with pityriasis versicolor, 15 patients with seborrhoeic dermatitis and matched controls, was studied. Patients with pityriasis versicolor showed a significantly lower response to M. furfur than patients with seborrhoeic dermatitis and controls.

Pityrosporum species as a cause of allergy and infection.

Pityrosporum species as a cause of allergy and infection.

Delayed-type hypersensitivity,in vitroT-cell responsiveness and risk of active coccidioidomycosis among HIV-infected patients living in the coccidioidal endemic area

The prognostic importance of specific and general tests of immune function were examined among a cohort of 170 subjects infected with human immunodeficiency virus type-1 (HIV), living in an area endemic for the fungal infection coccidioidomycosis. Using the proportional hazards model and multivariate analysis, lack of expression of coccidioidal delayed-type hypersensitivity (DTH) was found to be dependent on anergy in response to the non-coccidioidal antigens mumps, Trichophyton and Candida (relative hazard 4.2, 95% CI 1.8-9.8, P=0.001). Among subjects with CD4 lymphocyte counts >/=250 microl-1 on entry into the study, the in vitro lymphocyte transformation (LT) response to the coccidioidal antigen toluene spherule lysate was 4967+/-1652 (mean counts per minute (c.p.m.)+/-SEM) in subjects with coccidioidal DTH compared with 136+/-222 in those with negative DTH (P<0.001). However, amongst those whose CD4 count was <250 microl-1, LT responses were low and there was no significant difference based on coccidioidal DTH (P=0.965). Using the proportional hazards model and multivariate analysis, only a CD4 count <250 microl-1 was prognostically associated with the development of either active coccidioidomycosis or AIDS. These data indicate that immunodeficiency, particularly a CD4 lymphocyte count <250 microl-1, is the most important factor in the lack of expression of specific immunity to coccidioidomycosis and in the development of active coccidioidomycosis among HIV-infected individuals living in the coccidioidal endemic area.

Evolution of lymphocyte transformation to wasp venom antigen during immunotherapy for wasp venom anaphylaxis.

Venom immunotherapy (VIT) has proven to be safe and effective in wasp venom anaphylaxis. However, there are no good parameters to indicate when to stop venom immunotherapy. To evaluate the relationship of the lymphocyte transformation test (LTT) to history and specific IgE determination, and to address the time course of lymphocyte transformation responses to wasp (Vespula) venom during VIT and the possible utility of LTT to determine the duration of therapy. Peripheral blood mononuclear cells (PBMCs) of 18 individuals with a history of wasp sting anaphylaxis and a positive serum-venom-specific IgE, were stimulated with wasp venom before immunotherapy, at the end of a 5-day semi-rush immunotherapy and at 24 months during venom immunotherapy. Results, expressed as stimulation index (SI), were compared with the SI in seven asymptomatic stung controls. In controls the median (minimum-maximum) of the SI were 2.39 (0.52-3.39) before therapy and 2.39 (1.12-6.02) when repeated after 24 months. For patients the median (minimum-maximum) of the SI were 10.13 (1.19-44.88) before immunotherapy (d0), 2.73 (0.67-12.03) at the end of the build-up immunotherapy (d5) and 4.21 (0.88-14.66) at the end of 24 months of maintenance therapy (m24). The proliferation responses in vespid-allergic patients were significantly higher than in stung controls (P = 0.006) but only 13/18 patients showed a positive LTT result before the start of immunotherapy (sensitivity of the LTT 72%). When the LTT was repeated after a 5 day build-up hyposensitization course the SI significantly dropped as compared to the pre-treatment levels (P = 0.002). The SI of the LTT was negative in eight out of 18 patients at 24 months and the median values were significantly lower than before therapy (P = 0.03). Although, in the absence of sting challenge data it is not possible to draw conclusions about the predictive value of the LTT, our data may suggest that abolition of the LTT during VIT might indicate clinical insensitivity. Further studies, comparing the results of sting challenges, with the results of lymphocyte transformation will be necessary in order to evaluate the role of LTT in stopping immunotherapy.

Effects of Great Lakes Fish Consumption on the Immune System of Sprague–Dawley Rats Investigated during a Two-Generation Reproductive Study: II. Quantitative and Functional Aspects

The effects of Great Lakes fish contaminants on several quantitative and functional aspects of the immune system were investigated in the first (F1) and second (F2) generations of Sprague–Dawley rats. The F0rats were fed either a control diet or diets containing 5 or 20% lyophilized chinook salmon from the Credit River of Lake Ontario (LO) and Owen Sound point of Lake Huron (LH). The F1and F2pups were exposed to fishin utero, through the dam's milk to 21 days old, and through the dam's respective diets to 13 weeks of age. The study included an F1-reversibility (F1-R) phase in which rats at 13 weeks of exposure to fish or control diets were switched to the control diet for 3 months. The most outstanding finding was a statistically significant increase in absolute spleen leukocytes and absolute and percentage lymphocytes in the F2male rats fed the LH fish diets compared to the control and to those fed the LO fish diets with the 20% fish diets having higher cell numbers compared to the LO-5% fish diets. A parallel increase in the T-helper/inducer T-lymphocyte subset numbers was observed. Increased but statistically insignificant plaque-forming cell (PFC) numbers were obtained in the F2male rats fed the LH fish diets compared to those fed the LO fish diets and in the F1-R female group of rats fed the LH fish diet compared to those fed the LO fish diets. Phagocytosis by resident peritoneal macrophages was significantly increased in the F1male and F2female rats fed the fish diets compared to the control. The phagocytic activity was significantly higher in the F2-generation male and female rats fed the LO diets compared to those fed the LH diets. Other parameters including lymphocyte transformation in response to mitogens, the number ofListeria monocytogenesbacteria surviving in the rat spleens, and the natural killer cell activity were not affected significantly by any of the treatments. Overall, the effects of diets containing chinook salmon from the LO and LH sources on the immune system of rats were minimal and were on quantitative rather than on functional aspects of the system. Further focused research would be required in order to establish conclusively that the immune system of cohorts who ingest Great Lakes fish frequently is at a greater risk for adverse effects.

Cell‐mediated immune responses to Malassezia furfur serovars A, B and C in patients with pityriasis versicolor, seborrheic dermatitis and controls

It has been postulated that patients with Malassezia furfur-associated dermatoses have a deficient cell-mediated immune response to M. furfur. This study examined the cell-mediated immune responses to M. furfur serovars A, B and C of 10 patients with pityriasis versicolor and 10 age- and sex-matched controls; and 10 patients with seborrheic dermatitis and 10 age- and sex-matched controls. The responses to each serovar of M. furfur were assessed using the lymphocyte transformation assay and the leukocyte migration inhibition assay. The lymphocyte transformation responses of the patients with pityriasis versicolor to M. furfur serovars A, B and C (0/10, 6/10 and 5/10 respectively) were not significantly different from those of controls (0/10, 2/10 and 1/10). However, for patients with seborrheic dermatitis, significantly more patients' lymphocytes responded to serovars B and C (6/10 and 6/10 respectively) than those of controls (1/10 and 1/10). No patient or control responded to serovar A. In the leukocyte migration inhibition assay, the leukocytes from a greater proportion of patients with pityriasis versicolor (5/7) responded to serovar B than controls (2/10); and the leukocytes from a greater proportion of patients with seborrheic dermatitis (4/10) responded to serovar C than controls (0/9). Thus, this data did not indicate the presence of any cell-mediated immune deficiency to M. furfur in patients with pityriasis versicolor or seborrheic dermatitis, as measured by the lymphocyte transformation assay or the leukocyte migration inhibition assay. The greater responsiveness of T lymphocytes from patients may indicate that T lymphocytes might be involved in the pathogenesis of these diseases.

Lymphocyte responses to viral antigens and phytohaemagglutinin in persistently viraemic sheep and lambs experimentally infected with Border disease virus

Lymphocytes obtained from lambs 5 to 21 days after experimental infection with Border disease virus (BDV) showed significant blastogenic responses to live or inactivated BDV. Live virus stimulated significantly higher lymphocyte transformation (LT) responses than inactivated virus. Lymphocytes obtained from uninfected control and persistently infected lambs had no significant response to live or inactivated antigen. Lymphocyte responses to phytohaemagglutinin were significantly higher in control lambs than in experimentally infected lambs in samples obtained 5 to 10 days post-inoculation.

The syndrome of presumed ocular histoplasmosis in Mexico: a preliminary study.

A study to screen for the syndrome of presumed ocular histoplasmosis (SPOH) among native populations from three Mexican states was performed. Two of these states, Guerrero and Querétaro, were selected as histoplasmosis is endemic there, whereas Tlaxcala was considered a control, due to the absence of reported cases. A total of 253 individuals were submitted to ocular fundus examination to obtain evidence of SPOH. A high percentage of positive reactors to histoplasmin skin test (ST) was observed in Guerrero (83%) and Querétaro (53%), whereas in Tlaxcala positive ST were almost absent (2.04%). Only five individuals had retinal lesions, although these lesions were not characteristic of the syndrome. Stimulation of these individual's cells showed different patterns in the histoplasmin-induced lymphocyte transformation response, and two out of five individuals with retinal lesions presented a stimulated response, as well as three controls without lesions. Histocompatibility antigens (HLA) were determined in a sample of each population and no particular allele, including HLA-B7, was found to be related to SPOH as reported in the USA; however, HLA-B22 was found in three individuals who developed pulmonary histoplasmosis. Results do not provide clinical evidence or data on specific HLA risk factors, for the presence of SPOH in the population studied.

Lymphocyte transformation responses to phytohaemagglutinin and pokeweed mitogen in patients at differing stages of HIV infection: are they worth measuring?

To determine whether the routine measurement of lymphocyte transformation responses to mitogenic stimuli provide any information additional to that available from routine T cell CD4 and CD8 analysis in patients with HIV infection. The case records of 197 immunologically investigated HIV seropositive patients were reviewed. The influence of disease stage on T lymphocyte subsets and lymphocyte transformation responses (LyTR) to phytohaemagglutinin (PHA) and Pokeweed mitogen was assessed. The median CD3 and CD4 counts and LyTR to PHA and Pokeweed mitogen were highest in patients with persistent generalised lymphadenopathy (PGL) and decreased progressively in the order: asymptomatic patients, those with ARC, those with AIDS. LyTR to PHA was preserved in over 70% of all patients, but the response to Pokeweed mitogen was depressed in 8% of patients with PGL, 34% of asymptomatic patients, 68% of those with ARC and 78% of those with AIDS. Subnormal values of both CD4 + T cells and LyTR to Pokeweed mitogen were more common in patients with ARC and AIDS (68%) than in those who were asymptomatic or had PGL (20%). CD4 T cell analysis and LyTR to Pokeweed mitogen, but not to PHA, both correlate with disease states in patients with HIV infection.