Active,specific immunotherapy of stage III breast cancer

Summary Active specific immunization with autologous irradiated tumor cells (AITC) admixed with BCG was attempted in 49 stage III breast cancer patients whose median follow-up at present is 3 years. As a first immunizing procedure 41 patients received repeated intradermal inoculations and 8 had a single endolymphatic instillation (ELI). Skin response (SR) to AITC alone was induced after two to nine weekly immunizations. Eight of 41 patients with negative or weak responses were effectively reimmunized by ELI, as indicated by conversion and invigoration of SR. Following immunization, radiotherapy to breast and axilla was administered. Thereafter, fortnightly 5-FU and monthly boosters of AITC-BCG mixture were given for 2 years. Strength of response to AITC induced by active immunization was found to relate to subsequent disease recurrence, with 15% relapsing among the good responders and 53% among the weak and non-responders. Positive SR to AITC — once elicited — was steadily maintained in the majority of patients; its decline was associated with manifest disease recurrence. Conversion to AITC positivity in vivo following specific immunization was not detectable by the LMI assay. Lymphocyte stimulation (MLTI) by AITC in vitro was found in only 9 of 26 tested patients with positive in vivo SR to AITC. Cutaneous response to AITC appears to be the only parameter of antitumor response showing clinical correlation, while specific in vitro correlates of cell-mediated immunity were found unsuitable for monitoring patients undergoing specific immunotherapy. While in vivo PPD response was mainly unchanged or enhanced, in vitro lymphocyte stimulation by PPD and PHA showed a distinct decline at the time of relapse. The cumulative proportion of relapse among the immunotherapy patients at 3 years was 32% with mortality of 12% (13 relapsed, 5 died), both being significantly lower than reported results in stage III breast cancer without immunotherapy. It is concluded that specific immunization with AITC is feasible in most breast cancer patients with loco-regionally advanced disease and that this intervention is conducive to favorable modification of the course of their disease.     

Cellular oxidative responses and mycobacterial growth inhibition in aerosol and intradermal BCG-immunized guinea-pigs.

Although the dissemination of tuberculosis is aerogenic, less than 10% of infected subjects develop the active disease. Local immunity plays a major role in systemic cell-mediated immunity against this disease. BCG immunization may be more effective if administered via aerosol rather than intradermally. In this study, the immune responses seen in guinea-pigs vaccinated with a BCG aerosol were compared with those seen following intradermal vaccination. At regular intervals after each vaccination, the activation of alveolar macrophage was determined by their capacity to produce superoxides, phagosome-lysosome fusion and the inhibition of in vitro BCG growth. Concurrently, BCG multiplication or growth inhibition in the target organs was also determined. This study demonstrates that the alveolar route of BCG administration activated broncho-alveolar macrophage more effectively than the intradermal route. Superoxide production correlated with in vitro and in vivo inhibition of BCG growth. The spread, by the BCG inoculum, to the draining lymph nodes and spleen was similar for both test routes of administration. However, the lung BCG counts were significantly lower following intradermal vaccination. In contrast, the activation of broncho-alveolar macrophage was higher following aerogenic, rather than intradermal, BCG immunization.     

Repeated Aerosolized-Boosting with Gamma-Irradiated Mycobacterium bovis BCG Confers Improved Pulmonary Protection against the Hypervirulent Mycobacterium tuberculosis Strain HN878 in Mice

Mycobacterium bovis bacillus Calmette-Guerin (BCG), the only licensed vaccine, shows limited protection efficacy against pulmonary tuberculosis (TB), particularly hypervirulent Mycobacterium tuberculosis (Mtb) strains, suggesting that a logistical and practical vaccination strategy is urgently required. Boosting the BCG-induced immunity may offer a potentially advantageous strategy for advancing TB vaccine development, instead of replacing BCG completely. Despite the improved protection of the airway immunization by using live BCG, the use of live BCG as an airway boosting agent may evoke safety concerns. Here, we analyzed the protective efficacy of γ-irradiated BCG as a BCG-prime boosting agent for airway immunization against a hypervirulent clinical strain challenge with Mycobacterium tuberculosis HN878 in a mouse TB model. After the aerosol challenge with the HN878 strain, the mice vaccinated with BCG via the parenteral route exhibited only mild and transient protection, whereas BCG vaccination followed by multiple aerosolized boosting with γ-irradiated BCG efficiently maintained long-lasting control of Mtb in terms of bacterial reduction and pathological findings. Further immunological investigation revealed that this approach resulted in a significant increase in the cellular responses in terms of a robust expansion of antigen (PPD and Ag85A)-specific CD4⁺ T cells concomitantly producing IFN-γ, TNF-α, and IL-2, as well as a high level of IFN-γ-producing recall response via both the local and systemic immune systems upon further boosting. Collectively, aerosolized boosting of γ-irradiated BCG is able to elicit strong Th1-biased immune responses and confer enhanced protection against a hypervirulent Mycobacterium tuberculosis HN878 infection in a boosting number-dependent manner.     

Immunologic monitoring and immunotherapy in Ewing's sarcoma

Summary Serial immunological monitoring was performed on 31 patients with Ewing's sarcoma who were on a randomized immunotherapy trial with BCG administered by dermal scarification with a Heaf gun. Patients were skin-tested for delayed hypersensitivity reactions (DCHR) to recall antigens and extracts of tumor cells, and with keyhole limpet hemocyanin (KLH). In vitro testing consisted of lymphocyte counts, percentages of cells forming rosettes with sheep erythrocytes at 29° C and at 4° C, and leukocyte migration inhibition to tuberculin (PPD) and to 3 M KCl extracts of tumor cells. At the time of diagnosis, nearly all patients had positive DCHR to mumps and streptococcal antigens and were negative to PPD. Neither the skin tests nor the lymphocyte counts at this time gave useful prognostic information. In tests during and after therapy, the patients who responded and remained free of detectable disease had a higher incidence of DCHR to KLH and of rosette values in the normal range than did the patients who developed recurrent disease. The BCG immunotherapy had no apparent effect on immunologic parameters except for conversion of reactions to PPD.     

Interpretation of the PPD skin test in BCG-vaccinated children.

Skin testing with 5 tuberculin units (TU) of purified protein derivative (PPD) of tuberculin stabilized with polysorbate (Tween) 80 was done 3 months and 1 year after immunization with bacille Calmette-Guérin (BCG) vaccine in two groups of children: one group vaccinated at birth and another group at age 6 years. Interpretation of the PPD skin test with 5 TU is possible in children 1 year and older vaccinated with BCG at birth: if the diameter of induration is more than 10 to 12 mm the reaction cannot be ascribed to BCG vaccination and is highly suggestive of supervening infection with Mycobacterium tuberculosis or occasionally atypical mycobacteria. In contrast, the interpretation of a PPD test in children vaccinated at age 6 years is extremely difficult.     

The impact of maternal infection with Mycobacterium tuberculosis on the infant response to bacille Calmette–Guérin immunization

Bacille Calmette–Guérin (BCG) immunization provides variable protection against tuberculosis. Prenatal antigen exposure may have lifelong effects on responses to related antigens and pathogens. We therefore hypothesized that maternal latent Mycobacterium tuberculosis infection (LTBI) influences infant responses to BCG immunization at birth. We measured antibody (n = 53) and cellular (n = 31) responses to M. tuberculosis purified protein derivative (PPD) in infants of mothers with and without LTBI, in cord blood and at one and six weeks after BCG. The concentrations of PPD-specific antibodies declined between birth (median [interquartile range (IQR)]) 5600 ng ml⁻¹ [3300–11 050] in cord blood) and six weeks (0.00 ng ml⁻¹ [0–288]). Frequencies of PPD-specific IFN-γ-expressing CD4⁺T cells increased at one week and declined between one and six weeks (p = 0.031). Frequencies of IL-2- and TNF-α-expressing PPD-specific CD4⁺T cells increased between one and six weeks (p = 0.019, p = 0.009, respectively). At one week, the frequency of PPD-specific CD4⁺T cells expressing any of the three cytokines, combined, was lower among infants of mothers with LTBI, in crude analyses (p = 0.002) and after adjusting for confounders (mean difference, 95% CI −0.041% (−0.082, −0.001)). In conclusion, maternal LTBI was associated with lower infant anti-mycobacterial T-cell responses immediately following BCG immunization. These findings are being explored further in a larger study.     

Immune reactivity in cattle with ocular squamous cell carcinoma after intralesional BCG immunotherapy

Summary Lymphocyte stimulation with Con A and specific immune reactivity to BCG (antibody formation to BCG and DTH reaction to PPD) were determined in BCG-treated, surgically treated and untreated cows with ocular squamous cell carcinoma. In tumor-bearing cows the Con A-induced proliferation of lymphocytes was reduced when compared to healthy controls. This suppression consisted of a reduced blastogenic response to Con A of lymphocytes from tumor-bearing cows, and the presence of a factor in the sera of these animals, as these sera suppressed the blastogenic response of lymphocytes from healthy cows. BCG had only a minor influence on the suppressive activity. Antibodies to BCG were demonstrated in 50% of the BCG-treated animals. The formation of antibodies was not influenced by intradermal injection of PPD of Mycobacterium bovis. Absorption of a BCG antibody containing serum with BOSCC tumor extracts did not reveal the existence of cross reacting antigens between BCG and BOSCC. Pretherapeutic and posttherapeutic Con A reactivity could not be correlated with clinical response. Of the 30 BCG treated cows 29 developed a positive DTH reaction to PPD. Correlation between clinical response and immune reactivity was seen only with regard to the DTH reaction to PPD: this reaction remained positive for a longer period after treatment in animals with a favorable clinical outcome than in nonresponding animals.Animals were maintained under the guidelines laid down by the Faculty of Veterinary Medicine, State University, Utrecht, The NetherlandsGrant recipient of the Koningin Wilhelmina Fonds (Netherlands Cancer Foundation) Abbreviations used: BCG, Bacillus Calmette-Guerin; BOSCC, bovine ocular squamous cell carcinoma PBL peripheral blood leukocytes; PPD, purified protein derivative of Mycobacteria; DTH, delayed type hypersensitivity Con A, concanavalin A; PHA, phytohemagglutinin; PWM, pokeweed mitogen     

Serial immunologic assessment during a randomized trial of chemoimmunotherapy in acute myelogenous leukemia

Summary Thirty-one adults who had acute myelogenous leukemia and in whom remission had been induced and consolidated with chemotherapy were randomized to receive one of three maintenance schedules: (A) BCG + chemotherapy [1, 3-bis-(2-chlorethyl)-1-nitrosourea (BCNU) and cytosine arabinoside]; (B) splenectomy, followed 1 week later with BCG and chemotherapy; or (C) allogeneic leukemic cells, BCG, and chemotherapy. Serial immunologic assessments were performed at the onset of maintenance and every 3 months.No differences were found in duration of remission (median 209 days) or survival (median 454 days) among the three schedules. Six patients remain in remission after from 2–4 + years. Skin test responses, mitogen responses, mixed lymphocyte culture responses, antibody responses, and T and B lymphocyte numbers were depressed at the onset of maintenance therapy. Therapy clearly improved the state of anergy as defined by recall antigen responsiveness, and induced in vivo and in vitro PPD reactivity. However, immunotherapy resulted in a reduction of the number of T or B cells and of the in vitro lymphocyte response to mitogens and allogeneic cells. Serum obtained at diagnosis and during remission inhibited in vitro blastogenic responses in more than half the patients. These data indicate that chemoimmunotherapy given as described tended to be more immunosuppressive than stimulatory.     

The Tuberculin Skin Test (TST) Is Affected by Recent BCG Vaccination but Not by Exposure to Non-Tuberculosis Mycobacteria (NTM) during Early Life

The tuberculin skin test (TST) is widely used in TB clinics to aid Mycobacterium tuberculosis (M.tb) diagnosis, but the definition and the significance of a positive test in very young children is still unclear. This study compared the TST in Gambian children at 4½ months of age who either received BCG vaccination at birth (Group 1) or were BCG naïve (Group 2) in order to examine the role of BCG vaccination and/or exposure to environmental mycobacteria in TST reactivity at this age. Nearly half of the BCG vaccinated children had a positive TST (≥5 mm) whereas all the BCG naïve children were non-reactive, confirming that recent BCG vaccination affects TST reactivity. The BCG naïve children demonstrated in vitro PPD responses in peripheral blood in the absence of TST reactivity, supporting exposure to and priming by environmental mycobacterial antigens. Group 2 were then vaccinated at 4½ months of age and a repeat TST was performed at 20–28 months of age. Positive reactivity (≥5 mm) was evident in 11.1% and 12.5% infants from Group 1 and Group 2 respectively suggesting that the timing of BCG vaccination had little effect by this age. We further assessed for immune correlates in peripheral blood at 4½ months of age. Mycobacterial specific IFNγ responses were greater in TST responders than in non-responders, although the size of induration did not correlate with IFNγ. However the IFNγ: IL-10 ratio positively correlated with TST induration suggesting that the relationship between PPD induced IFNγ and IL-10 in the peripheral blood may be important in controlling TST reactivity. Collectively these data provide further insights into how the TST is regulated in early life, and how a positive response might be interpreted.     

Transfer factor—Transfer of tuberculin cutaneous sensitivity in an allogeneic and xenogeneic monkey model

Tuberculin cutaneous sensitivity can be transferred from rhesus monkeys, sensitized to tuberculin using BCG, to rhesus and cynomolgus recipients with viable or disrupted leucocytes, and with a dialysed lysate preparation from 3 × 10⁸ leucocytes. Dialysable transfer factor (TF) using the lyophilized aqueous dialysate of a leucocyte lysate prepared by the freeze-thaw method did not give an active material. Modifications to the preparative method, in that leucocytes from fresh blood were disrupted gently by mechanical shearing forces, the lysate dialysed against a balanced salt solution and injected without lyophilization, yielded an active preparation. Transferred tuberculin (PPD) skin reactivity, confirmed by biopsy, was always less than the reactivity of the donor monkey and lasted for approximately 2–3 months. Although donor monkeys showed good in vitro lymphocyte transformation response to antigen stimulation, recipient monkeys which became skin test positive did not have a concomitant blastogenic response to PPD.     

Recurrent malignant melanoma: effect of adjuvant immunotherapy on survival.

Twenty-nine patients referred consecutively to a cancer clinic because of recurrent metastatic malignant melanoma were given 5 mg of Connaught Laboratories bacillus Calmette-Guérin (BCG) by multiple cutaneous puncture at weekly and later at monthly intervals. Eight were also treated with autologous tumour vaccine and three with intralesional BCG. This group was compared with a retrospective control group of 54 patients treated with surgery and radiotherapy alone after recurrence. Prognostic features such as site of primary and of first metastasis, disease-free interval, age and sex were similar in the two groups. However, the median survival from the time of first recurrence was 12 months in the control group but 21 months in the BCG-treated group. The major improvement was in patients with disease limited to the regional lymph nodes: the median survival was 16 months in the control group but over 32 months in the BCG-treated group. Autologous tumour vaccine appeared to have no effect on survival. Serial testing of immunocompetence did not offer any prognostic advantage, although the results of some tests correleated well with extent of disease.     

Intralymphatic administration of BCG in melanoma patients

Summary From November 1973 to December 1974, 20 patients with advanced malignant melanoma were treated with BCG given by intralymphatic route at the Cancer Institute of Milan. The lyophilized Pasteur BCG was used. Patients were treated with a single dose ranging from 0.2–80 mg. Patients' performance status was never severely impaired.The most frequent side effects were fever, lymphangitis, and lymph node enlargement.Variations were observed in white cell count, ERS and immunoglobulins; in no case did we find evidence of liver toxicity or tumor growth enhancement. It is concluded that the intralymphatic route is a safe way of administrating BCG.     

BCG Moreau Rio de Janeiro: an oral vaccine against tuberculosis--review

The vaccine Bacillus of Calmette Guérin (BCG) was originally developed in France as an oral vaccine against tuberculosis. The oral use of this vaccine was replaced by the parenteral route in almost all countries after the Lubeck disaster. In contrast, Brazil retained the oral delivery of the vaccine until the mid-seventies when it was replaced by the intradermal route. This change in route of delivery was mainly secondary to pressure by medical practitioners based on the poor responses of oral immunized subjects to purified protein derivative (PPD) skin tests. Even after the change of route of delivery, Ataulpho de Paiva Foundation continued making the oral vaccine. Currently, BCG Moreau has been described as one of the most immunogenic and with fewer side effects than other BCGs. The genomics, proteomics and vaccine trials for oral BCG Moreau Rio de Janeiro are currently under investigation. In this review, we intend to describe the history of BCG Moreau Rio de Janeiro in Brazil.     

Murine Splenic Natural Killer Cells Do Not Develop Immunological Memory after Re-Encounter with Mycobacterium bovis BCG

Several lines of evidence have recently suggested that natural killer (NK) cells develop immunological memory against viral infections. However, there is no apparent evidence that NK cells acquire specific memory against Mycobacterium bovis bacillus Calmette—Guérin (BCG), the only currently licensed vaccine for preventing tuberculosis. In the present study, we investigated whether murine splenic NK cells can be activated by BCG in a dendritic cell (DC)-independent or -dependent manner, and furthermore examined whether these NK cells acquire specific memory following BCG vaccination. NK cells isolated from spleens of BCG-immunized mice produced interferon (IFN)γ through direct BCG stimulation in the absence of antigen-presenting cells; however, NK cells from control animals similarly directly responded to BCG, and the response level was not statistically significant between the immunized and the naïve NK cells. When purified NK cells that had been exposed to BCG were cocultured with RAW murine macrophages infected with BCG, the antibacterial activity of the macrophages was strongly enhanced; however, its level was similar to that by naïve NK cells, which had not been exposed to BCG. When splenocytes harvested from BCG-immunized mice were stimulated with purified protein derivative (PPD) derived from Mycobacterium tuberculosis, a specific IFNγ response was clearly observed, mainly attributed to NK cells and memory CD4⁺ T cells. To investigate whether these NK cells as well as the T cells are activated by cell−cell interaction with DCs presenting mycobacterial antigens, NK cells isolated from BCG-immunized mice were cocultured with splenocytes harvested from naïve mice in the presence of PPD stimulation. However, no IFNγ response was found in the NK cells. These results suggest that murine splenic NK cells do not develop BCG-specific immunological memory in either a DC-independent or -dependent manner.     

Immune reactions in patients with superficial bladder cancer after intradermal and intravesical treatment with bacillus Calmette-Guérin

Summary The immune reactivity of patients with strongly recurrent superficial bladder cancer was followed after combined intravesical and intradermal bacillus Calmette-Guérin (BCG) immunotherapy. All patients in this study were previously treated without success with intravesical chemotherapy. The BCG treatment regimen consisted of weekly administrations with BCG (RIVM) for six consecutive weeks, both intravesically and intradermally. In this study, sera and peripheral blood leukocytes (PBL) of patients were tested serially. Besides BCG-antigen-specific reactions, e.g. skin reactivity to purified protein derivatives of Mycobacterium tuberculosis (PPD), antibody formation and antigen stimulation of PBL in vitro, non-antigen-specific immune reactivities were also measured, e.g. mitogen response and spontaneous cytotoxic activity of PBL. In addition the antibody response to bladder carcinoma antigens and the cytotoxic activity of PBL for the bladder carcinoma cell line T24 and the natural-killer-sensitive K562 cell line were investigated. The results obtained from the various assays were evaluated for their prognostic value in relation to the length of the tumor-free interval after the BCG treatment. Because sera and PBL were only obtained during the first 6 months after the BCG treatment, the immune reactivity was compared to the clinical results at that same time. At 6 months after therapy 12 out of 40 BCG-treated patients were tumor-free whereas 28 out of 40 showed a recurrence. Skin reactivity to tuberculin PPD was measured in 40 patients during a period of 3–6 months after therapy. Of patients who showed a recurrence of the tumor within 6 months, 48% of them showed a transient response or developed no response at all to PPD. In the group of patients with a longer tumor-free period (n=10), only one patient lost the response to tuberculin PPD. Although PBL of a limited number of patients were tested, it was observed that the cytotoxicity to the bladder carcinoma cell line T24, and the natural-killer-sensitive K562 cell line increased in a number of the patients (7 out of 14, and 9 out of 14 respectively). Reactivity of PBL to mitogens and subset distribution (ratio T-helper: T-suppressor/cytotoxic) were not influenced by the BCG treatment. Antibody response to mycobacterial antigen was detected in 9 out of 23 patients investigated. Of these 9 patients, 8 belonged to the group with a recurrence of the tumor within 6 months (n=17). There was no correlation between the skin reactivity and the antibody response to tuberculin PPD. Furthermore, none of the 25 patients showed an antibody response to bladder carcinoma antigens. Sera of bladder carcinoma patients (n=19) reduced the mitogen-induced proliferation of lymphocytes, compared to sera of healthy controls (n=13), indicating the presence of circulating suppressor factor(s). Our results indicate that the absence of a Mantoux conversion or the presence of transient reaction to tuberculin PPD were highly related (91%) to a relapse of the disease. On the other hand, the cytotoxic activity of PBL to T24 and K562 cell lines, or their reactivity to tuberculin PPD or mitogens, gives no predictive information about the clinical results (tumor-free interval) of the BCG therapy. Abbreviations used: BCG, bacillus Calmette-Guérin; NK, natural killer; PBL, peripheral blood leukocytes; PPD, purified protein derivative of Mycobacterium tuberculosis; ELISA, enzyme-linked immunosorbent assay     

BCG—PPD的制备及应用

用三氯醋酸(TCA)和硫酸铵(AS)综合法,由卡介菌苗(BCG)培养滤液中提纯制得卡介菌素纯蛋白衍生物(BCG—PPD)。BCG—PPD的纯度和结核菌素纯蛋白衍生物国际标准(PPD-S)及中国标准(PPD—C)相近,高于加拿大标准(PPD—CT68)和丹麦标准(PPD—RT23)。在BCG免疫豚鼠中,BCG—PPD的皮肤迟发型变态反应(DTH)大于结核菌素纯蛋白衍生物(PPD)的DTH反应。在结核菌感染豚鼠组中,BCG—PPD的DTH反应小于PPD的DTH反应.在检查333名新生儿接种BCG12周后的免疫     

Intrapulmonary BCG cell wall vaccination in mice

Mice of two inbred strains, Balb/c and C3H/He, were given three dosages of mycobacterium bovis BCG (5 X 10(4), 5 X 10(2) and 5 colony forming units) by either the intravenous route or by a direct intratracheal (non-aerosol) route. The magnitude of the infectivity of these inoculae given by these routes was assessed by measurement of weight changes and mycobacterial multiplication in the spleen and lung. As expected, the Balb/c strain was more susceptible to infection than the C3H/He strain. However, for both strains, infection by the intratracheal route resulted in mycobacterial counts in the lungs which were more than seven-fold higher than mycobacterial counts after intravenous challenge. Naive Balb/c mice were immunized with BCG cell wall vaccine by the intratracheal route, by the intravenous route or by subcutaneous immunization. Four weeks later mice were challenged with live BCG by the intratracheal route. Following challenge, mycobacterial counts in the lungs of mice immunized by the intratracheal route, but not in the lungs of the mice immunized by the intravenous and subcutaneous routes, were significantly lower compared to controls. These results suggest that immunization with killed BCG by the intratracheal route imparts more effective mycobacterial intrapulmonary immunity than immunization by systemic routes.     

Natural cell-mediated cytotoxicity in normal human peripheral blood lymphocytes and its in vitro boosting with BCG

Summary Natural cell-mediated cytotoxicity (NCMC) against K-562 human erythroleukemic cells was monitored in an overnight chromium release assay using normal human peripheral blood lymphocytes (PBL) as effector cells. Two hundred and ten normal individuals were tested from 3 to 24 times over a period of 3 years. The level of NCMC was shown to vary from 4% to 46% lysis at an effector-to-target cell ratio of 5/1; males had higher levels of activity than females (P<0.001). A group of individuals with low natural killer (NK) cell activity (below the 90% tolerance limit) was identified in replicate experiments and 60% of them were young women (ages 20–39). In vitro boosting of NK activity with Bacillus Calmette-Guérin (BCG) was also studied; overall, 56% of normal individuals responded positively to BCG. There was a significant (P<0.0001) correlation between the unstimulated level of NCMC and the in vitro boosting with BCG, as 63% of individuals with a normal level of NK activity could be boosted as against only 19% of persons with low NK activity. We have also established the in vivo relevance of this in vitro test by determining the degree of correlation between responses to in vitro boosting with BCG and a positive or negative reaction in a hypersensitivity skin test using 5 IU of PPD (purified protein derivative of BCG). Our results indicate that NCMC is an individual trait that varies little under physiological conditions, and that the response to BCG is a characteristic property of the effector lymphocyte, depending primarily on the unstimulated level of NCMC.     

Long-Lived Memory B-Cell Responses following BCG Vaccination

The role of T-cells in immunity against Mycobacterium tuberculosis (M. tuberculosis) infection has been extensively studied, however, that of B-cells still remains comparatively unexplored. In this study, we determined the presence and frequencies of mycobacteria-specific memory B-cells (MBCs) in peripheral blood from clinically healthy, Bacillus Calmette Guerin (BCG) vaccinated (n = 79) and unvaccinated (n = 14) donors. Purified protein derivative (PPD)-specific MBCs were present in most donors (both vaccinated and unvaccinated) but their frequencies were significantly higher in vaccinated than in unvaccinated donors. MBCs specific for other mycobacterial antigens [antigen-85A (Ag85A), antigen-85B (Ag85B), 6 kDalton early secretory antigenic target (ESAT-6) and the 10 kDalton-culture filtrate protein (CFP-10)] were less prevalent than those recognising PPD. Furthermore, PPD-specific MBCs were detected in BCG vaccinated donors without ESAT-6 and CFP-10 specific responses. Together, these results indicate that BCG vaccination induces long-lived MBC responses. Similar patterns of response were seen when we examined mycobacteria-specific antibody and T-cell responses in these donors. Our data show for the first time that BCG vaccination elicits long-lived mycobacteria-specific MBC responses in healthy individuals, suggesting a more substantial role of B-cells in the response to BCG and other mycobacterial infections than previously thought.     

Suppression of in vitro lymphocyte responsiveness to purified protein derivative by measles virus. A reexploration of the phenomenon.

Clinical measles and measles vaccination have classically been associated with transient in vivo impairment of delayed hypersensitivity-type responses, especially skin test reactivity to purified protein derivative (PPD). In vitro data appeared to substantiate this in vivo observation by the demonstration of suppression of lymphocyte responsiveness to PPD by measles. Utilizing a measles preparation which has been recently demonstrated to elicit specific blastogenesis of sensitized human lymphocytes in vitro, we have reexplored the question of in vitro suppression of lymphocyte responsiveness to PPD by this virus. In contrast to previous reports, this study demonstrates that the addition of both measles and PPD to lymphocyte cultures can have a variable effect on lymphocyte responsiveness to PPD alone. This effect varies from marked inhibition to enhancement beyond a summation effect. The response is different for each lymphocyte donor and is dose related but cannot be predicted on the basis of combinations of high or low concentrations of either antigen. Purified, attenuated measles virus (Enders' strain), which uniformly suppressed in vitro lymphocyte reactivity when tested alone also demonstrated a significant dose related enhancement of the response to PPD alone. The present data suggest a reconsideration of the supposed importance of transient diminution of skin test reactivity during measles infection or immunization.