Novel therapeutic vaccine: granulysin and new DNA vaccine against Tuberculosis

PURPOSE

Multi-drug resistant (MDR) Mycobacterium Tuberculosis (M.TB) is a big problem in the world. We have developed novel TB therapeutic vaccines.

METHODS AND RESULTS

DNA vaccine expressing mycobacterial heat shock protein 65 and IL-12 was delivered by the hemagglutinating virus of Japan (HVJ)-envelope. M. TB, MDR-TB or extremenly drug resistant (XDR-TB) was injected i.v. into DBA/1 mice, and treated with the vaccine three times. This HVJ-E/Hsp65DNA+IL-12DNA vaccine provided strong therapeutic efficacy against MDR-TB and XDR-TB (prolongation of survival time and the decrease in the number of TB) in mice. Therapeutic effect of this vaccine on TB infection was also demonstrated in chronic TB infection murine model using aerosol infection intratracheally. On the other hand, granulysin protein produced from CTL has lethal activity against TB. Granulysin protein vaccine also exerted strong therapeutic effect. Furthermore, we extended our studies to monkey model, which is currently the best animal model of human TB. Hsp65DNA+IL-12 DNA vaccine exerted strong therapeutic efficacy (100% survival and augmentation of immune responses) in the TB-infected monkeys. In contrast, the survival of the saline control group was 60% at 16 week post-challenge. HVJ-Envelope/HSP65 DNA+IL-12 DNA vaccine increased the body weight of TB-infected monkeys, improved the erythrocyte sedimentation rate, and augmentated the immune responses (proliferation of PBL and IL-2 production). The enhancement of IL-2 production from monkeys treated with this vaccine was correlated with the therapeutic efficacy of the vaccine.

CONCLUSION

These data indicate that novel vaccines might be useful against TB including XDR-TB and MDR-TB for human therapeutic clinical trials.

Development of therapeutic and prophylactic vaccine against Tuberculosis using monkey and transgenic mice models

PURPOSE

BCG is not efficacious against M. tuberculosis (TB) in adult. Therefore, novel TB vaccines were established by using three kinds of animal models (cynomolgus monkey model which is the best animal model of human TB, IL-2R knock out SCID mice as a human immune model, and granulysin transgenic mouse).

METHODS AND RESULTS

DNA vaccine expressing TB Hsp65 and IL-12 was delivered by the hemagglutinating virus of Japan (HVJ)-envelope. The BCG prime followed by Hsp65+IL-12/HVJ vaccine boost showed a synergistic effect in the TB-infected cynomolgus monkey (100% survival). In contrast, 33% of monkeys were alive in BCG alone group. Furthermore, the prolongation of survival period of the monkey was observed by the combination of BCG and DNA vaccine even when the boost was performed after long-term period (4month) from prime. This combination also improved the erythrocyte sedimentation rate (ESR), increased the body weight, and augmented the proliferation of PBL and IL-12 production at higher levels than BCG alone or saline. Furthermore, this vaccine exerted therapeutic efficacy in IL-2R knock out SCID-PBL/hu mice, which were transplanted with human T cells. Granulysin is an important defensive molecule expressed by human T cells and NK cells and has a cytolytic activity against microbes including Mycobacterium tuberculosis (TB) and tumors. Expression of 15kD (15K) granulysin protein and mRNA in CD8 positive T cells in the patients infected with drug sensitive (TB) or multi-drug resistant (MDR-TB) M. tuberculosis were lower than that in the healthy volunteers, suggesting that granulysin treatment might improve the tuberculous disease in human. Therefore, we established two kinds of granulysin transgenic mice (15K granulysin transgenic mice and 9K granulysin transgenic mice). It was demonstrated that 15K granulysin transgenic mice as well as 9K granulysin transgenic mice exerted in vivo anti-TB effect, including the decrease of the number of TB and augmentation of the CTL activity. These are the first findings which demonstrate in vivo effects of 15K granulysin and 9K granulysin against TB infection. Moreover, DNA vaccine expressing 15K granulysin showed a therapeutic activity against TB in mice.

CONCLUSION

These data indicate that monkey, IL-2R gene-knock out SCID-PBL/hu and granulysin transgenic mice models provide useful tools for the development of novel vaccines (HVJ-Envelope/Hsp65 DNA + IL-12 DNA vaccine and granulysin vaccine) against TB.

Novel prophylactic and therapeutic vaccine against tuberculosis

We have developed a novel tuberculosis (TB) vaccine; a combination of the DNA vaccines expressing mycobacterial heat shock protein 65 (HSP65) and interleukin 12 (IL-12) delivered by the hemagglutinating virus of Japan (HVJ)-envelope and -liposome (HSP65+IL-12/HVJ). This vaccine provided therapeutic efficacy as well as remarkable protective efficacy via CD8(+) T and CD4(+) T cells in murine models compared with the saline controls, on the basis of CFU of number of multi-drug resistant TB (MDR-TB), and survival of extremely drug resistant TB (XDR-TB) challenged mice. Furthermore, we extended our studies to a cynomolgus monkey model, which is currently the best animal model of human tuberculosis. This vaccine exerted therapeutic efficacy (survival and immune responses) in the TB-infected monkeys. These data indicate that our novel DNA vaccine might be useful against Mycobacterium tuberculosis including XDR-TB and MDR-TB for human therapeutic clinical trials.

Evaluation of a novel vaccine (HVJ-liposome/HSP65 DNA+IL-12 DNA) against tuberculosis using the cynomolgus monkey model of TB

We have developed a novel tuberculosis (TB) vaccine; a combination of the DNA vaccines expressing mycobacterial heat shock protein 65 (HSP65) and interleukin 12 (IL-12) delivered by the hemagglutinating virus of Japan (HVJ)-liposome (HSP65+IL-12/HVJ). This vaccine provided remarkable protective efficacy in mouse and guinea pig models compared to the BCG vaccine, on the basis of an induction of the CTL activity and improvement of the histopathological tuberculosis lesions, respectively. Furthermore, we extended our studies to a cynomolgus monkey model, which is currently the best animal model of human tuberculosis. This novel vaccine provided a higher level of the protective efficacy than BCG based upon the assessment of mortality, the ESR, body weight, chest X-ray findings and immune responses. Furthermore, the combination of HSP65+IL-12/HVJ and BCG by the priming-booster method showed a synergistic effect in the TB-infected cynomolgus monkey (100% survival). These data indicate that our novel DNA vaccine might be useful against Mycobacterium tuberculosis for human clinical trials.

Novel recombinant BCG and DNA-vaccination against tuberculosis in a cynomolgus monkey model

We have developed two novel tuberculosis (TB) vaccines: a DNA vaccine combination expressing mycobacterial heat shock protein 65 (Hsp65) and interleukin-12 (IL-12) by using the hemagglutinating virus of Japan (HVJ)-liposome (HSP65+IL-12/HVJ) and a recombinant BCG harboring the 72f fusion gene (72f rBCG). These vaccines provide remarkable protective efficacy in mouse and guinea pig models, as compared to the current by available BCG vaccine. In the present study, we extended our studies to a cynomolgus monkey model, which is currently the best animal model of human tuberculosis, to evaluate the HSP65+IL-12/HVJ and 72f rBCG vaccines. Vaccination with HSP65+IL-12/HVJ as well as 72f rBCG vaccines provided better protective efficacy as assessed by the Erythrocyte Sedimentation Rate, chest X-ray findings and immune responses than BCG. Most importantly, HSP65+IL-12/HVJ resulted in an increased survival for over a year. This is the first report of successful DNA vaccination and recombinant BCG vaccination against M. tuberculosis in the monkey model.

Prospective study of serological conversion as a risk factor for development of leprosy among household contacts

Although the prevalence of leprosy has declined over the years, there is no evidence that incidence rates are falling. A method of early detection of those people prone to develop the most infectious form of leprosy would contribute to breaking the chain of transmission. Prophylactic treatment of serologically identified high-risk contacts of incident patients should be an operationally feasible approach for routine control programs. In addition, classification of high-risk household contacts will allow control program resources to be more focused. In this prospective study, we examined the ability of serology used for the detection of antibodies to phenolic glycolipid I of Mycobacterium leprae to identify those household contacts of multibacillary leprosy patients who had the highest risk of developing leprosy. After the start of multidrug therapy for the index case, a new case of leprosy developed in one in seven of the 178 households studied. In households where new cases appeared, the seropositivity rates were significantly higher (P < 0.001) than those in households without new cases. Seropositive household contacts had a significantly higher risk of developing leprosy (relative hazard adjusted for age and sex [aRH], 7.2), notably multibacillary leprosy (aRH = 24), than seronegative contacts.

Serial measurement of serum cytokines, cytokine receptors and neopterin in leprosy patients with reversal reactions

Serum levels of cytokines (IL-4, IL-5, IFN-gamma, TNF-alpha), cytokine receptors (TNFR I and II) and one monokine (neopterin) were estimated in seven leprosy patients to establish disease associated markers for reversal reactions (RR). Sera were collected at diagnosis of leprosy, at the onset of reversal reaction and at different time points during and at the end of prednisone treatment of reactions. It was expected that the serum cytokine and monokine profile before and at different time points during reactions would provide guidelines for the diagnosis and monitoring of reversal reactions in leprosy. The cytokines and cytokine receptors were measured by ELISA, whereas a radioimmunoassay was used for neopterin measurement. Six of the seven patients showed increased levels of neopterin either at the onset of RR or 1 month thereafter, and levels declined on prednisone treatment to that seen at the time of diagnosis without reactions. No consistent disease associated cytokine profile was observed in these patients. Interestingly, serum TNF-alpha levels were increased in the same patients even after completion of prednisone treatment, indicating ongoing immune activity. In conclusion, this study demonstrates that despite cytokines levels in leprosy serum being inconsistent in relation to reversal reactions, serum neopterin measurement appears to be an useful biomarker in monitoring RR patients during corticosteroid therapy.

Improvement in psoriasis after intradermal administration of delipidated, deglycolipidated Mycobacterium vaccae (PVAC): results of an open-label trial

The aim of new treatments for psoriasis is to induce extended remissions with fewer side-effects. Previous studies suggest that Mycobacterium vaccae, a harmless organism prepared as a heat-killed suspension, may induce periods of remission in some psoriasis patients after intradermal administration. To assess a more potent derivative of M. vaccae, we conducted an open-label study in which 20 patients with moderate to severe psoriasis (Psoriasis Area and Severity Index of 12-35) received two intradermal inoculations of heat-killed, delipidated, deglycolipidated M. vaccae (DD-MVAC or 'PVAC') in lesion-free deltoid skin, separated by a period of 3 weeks. Twelve weeks after the injections, 13 out of 20 patients (65%) showed marked improvement in the PASI score (> 50% reduction), three were unchanged (< 25% reduction), three had worsened (> 5% increase), and one was withdrawn from the trial because of an exfoliative flare. At 24 weeks, 13 out of 19 patients continued to show > 50% improvement that, in some, lasted for 6 months or longer. Patients classified as good responders at 12 or 24 weeks were then offered additional PVAC injections after 24 weeks if the PASI reached 8 or higher. Intra-dermal administration of PVAC was safe, well tolerated, and induced clinically significant improvement in many psoriasis patients. A randomized, double-blind, controlled study is warranted.

Malignant T-cell lymphoma mimicking lepromatous leprosy

We describe a 16-year-old Filipino boy who presented with skin lesions highly suggestive of lepromatous leprosy, but further assessment established a diagnosis of malignant T-cell lymphoma. This case emphasizes the extensive differential diagnosis of leprosy, as well as the importance of obtaining skin biopsies for diagnostic confirmation.

Detection of phenolic glycolipid I of Mycobacterium leprae in sera from leprosy patients before and after start of multidrug therapy

A total of 100 untreated new leprosy patients were recruited prospectively and examined for the presence of phenolic glycolipid I (PGL-I) antigen in their serum specimens by dot enzyme-linked immunosorbent assay (ELISA) using rabbit anti-PGL-I antiserum. The presence of circulating PGL-I antigen was closely related to the bacterial indices (BI) of the patients. The PGL-I antigen was detectable in 27 (93.1%) of 29 patients with a BI of 4.0 or above and in 15 (68.2%) of 22 patients with a BI of 3.0 to 3.9. However, none of the 37 patients with a BI of less than 1.9 had detectable PGL-I antigen by the methods used in this study. The level of PGL-I in serum declined rapidly by about 90% 1 month after the start of multidrug therapy. This study showed clearly that anti-PGL-I IgM antibodies and circulating PGL-I antigen levels reflect the bacterial loads in untreated leprosy patients. The serological parameters based on the PGL-I antigen may therefore be useful in the assessment of leprosy patients at the time of diagnosis and possibly in monitoring patients following chemotherapy.

Improvement in psoriasis after intradermal administration of heat-killed Mycobacterium vaccae

BACKGROUND

New treatments for psoriasis are being developed, but many are associated with limited efficacy, side-effects, or rapid recurrence after discontinuation. Thus, the aim of new agents is to induce longer term remissions with fewer side-effects. Preliminary studies have shown that Mycobacterium vaccae, a nonpathogenic organism prepared as a heat-killed suspension, may induce periods of remission in some psoriasis patients when administered intradermally.

METHODS

To further assess the efficacy and tolerability of M. vaccae in patients with moderate to severe psoriasis (psoriasis area and severity index (PASI) of 12-35), we conducted an open label study whereby 24 patients received two intradermal inoculations of M. vaccae in lesion-free deltoid skin, separated by a period of 3 weeks.

RESULTS

Twelve weeks after starting treatment, 14 of 24 patients (58%) showed marked improvement in the PASI score (greater than 50% reduction), two had moderate improvement (25-50% reduction), six were unchanged (< 25% reduction), and two had worsened (> 5% increase). By 24 weeks, 11 of 22 patients continued to show greater than 50% improvement. Five patients had complete clearance of skin lesions that lasted for at least 6 months.

CONCLUSIONS

Intradermal administration of heat-killed M. vaccae suspension was well tolerated and induced clinically significant improvement in a majority of psoriasis patients in this cohort. Placebo-controlled testing to further define the efficacy of this treatment is warranted.

Cutaneous delayed-type hypersensitivity responsiveness in lepromatous and borderline lepromatous leprosy patients as determined by MULTITEST CMI

To assess cell mediated immune (CMI) function in patients with lepromatous and borderline lepromatous leprosy (LL and BL), 35 patients were examined with the MULTITEST CMI system to evaluate cutaneous delayed-type hypersensitivity (DTH) responsiveness to 7 recall antigens. Reactions were assessed quantitatively and qualitatively. In addition, patients were classified as "responsive" (> or = 2 positive reactions), "hypo-responsive" (1 positive reaction), or anergic. Only hyporesponsive and anergic patients were re-tested. In 23 patients tested before treatment started (Group 1), 9 were responsive, 4 hypo-responsive, and 10 anergic. Upon re-testing, 10 of the 14 hyporesponsive-anergic subjects showed improvement. In 12 patients assessed after therapy initiation (Group 2), 9 were responsive and 3 others became responsive upon re-testing. Quantitative assessment indicated variable deficiencies in cutaneous DTH reactivity that, in many cases, improved with therapy. Correlations between reactivity and disease severity (LL versus BL) or duration of disease were not observed. The MULTITEST CMI system provided a convenient, safe, and reproducible method to assess cutaneous DTH responsiveness in LL and BL patients. Our findings indicated that most LL and BL patients are able to generate detectable but generally fewer and less robust cutaneous DTH responses to recall antigens, many improving with therapy. However, a semi-quantitative classification whereby patients that reacted to 2 or more antigens were considered "responsive" showed little difference between patients and controls. Overall, the data support the contention that deficits in cutaneous DTH responsiveness probably neither predispose nor necessarily accompany lepromatous disease, a practical consideration as efforts to develop a leprosy vaccine continue.

Multiple lesions of sporotrichoid leishmaniasis in a Filipino expatriate

Sporotrichoid cutaneous leishmaniasis (CL) was diagnosed in a Filipino man who had worked in Saudi Arabia for 2 years. Two primary lesions-one on the forearm and one on the abdomen-were characterized by "satellite" papules and subcutaneous nodules extending proximally in a sporotrichoid pattern. Leishmania organisms were found in both primary lesions and a subcutaneous nodule. There was no evidence of systemic involvement. Recognition that Old World CL may disseminate through lymphatic channels has diagnostic and therapeutic importance.

Recombinant interleukin-2 in lepromatous leprosy lesions: immunological and microbiological consequences

Seven patients with lepromatous leprosy (LL) were inoculated with recombinant interleukin-2 (rIL-2) at 5 lesional sites on the back, four sites receiving one dose of 10 micrograms and biopsy specimens being obtained on 4 consecutive days after the injection. At the 5th site, rIL-2 was instead administered over several days, three patients receiving a total dose of 40 micrograms and 4 patients 150 micrograms, while biopsy specimens from this site were obtained 7, 14 and 21 days after the first injection. Most injection sites developed features of a delayed-type hypersensitivity reaction, namely erythema and induration at the injection site, infiltrates rich in T helper cells, monocytes, and Langerhans cells, and at sites receiving higher doses, multinucleated Langhans giant cells and epithelioid granulomas. In some patients, there were favourable shifts in histological classification or small changes in bacterial load. Low doses of rIL-2 injected into LL lesions rapidly enhance cellular immunity and may alter the histological classification or bacterial load at the injection site.

Primary dapsone resistance in Cebu, The Philippines; cause for concern

At a time when primary dapsone resistance was prevalent in many leprosy endemic areas, Cebu in The Philippines reported only 3.6% in the period 1975-1978 and later 8.1% in the period 1979-1982. In our current study of patients in the period 1988-1992, the number increased dramatically to 52.7%. In addition, 7.9% of the isolates are highly resistant to dapsone, a level of resistance not seen in earlier studies. This finding could have severe ramifications to the World Health Organization's multidrug therapy (WHO-MDT) mode of treatment, where dapsone is one of the principal drugs. Moreover, the increase in primary dapsone resistance may be a contributing factor in the recent finding that there has been no decline in the number of new cases found in Cebu, even after the implementation of WHO-MDT in 1985. There is a need for new drugs that could be included in the multidrug treatment for multibacillary and paucibacillary leprosy.

The Philippine cynomolgus monkey (Macaca fasicularis) provides a new nonhuman primate model of tuberculosis that resembles human disease

A nonhuman primate model of tuberculosis that closely resembles human disease is urgently needed. We have evaluated the Philippine cynomolgus monkey, Macaca fasicularis, as a model of TB. Cynomolgus monkeys challenged intratracheally with extremely high doses of Mycobacterium tuberculosis (10(5) or 10(4) CFU) developed an acute, rapidly progressive, highly fatal multilobar pneumonia. However, monkeys challenged with moderate or low doses of M. tuberculosis (</=10(3) CFU) developed a chronic, slowly progressive, localized form of pulmonary TB, akin to the disease in humans, that was frequently accompanied by such clinical syndromes as ocular tuberculosis, meningitis and tuberculous spondylitis. A significant proportion of monkeys challenged with 10(2) or 10(1) CFU contained the infection in a subclinical state. The Philippine cynomolgus monkey model is an excellent model of chronic TB and provides an opportunity to study subclinical and potentially latent disease in an animal model.

Minocycline in lepromatous leprosy

Twelve patients were treated with three dose levels of minocycline for 30 days, primarily to detect the dose-related effects on Mycobacterium leprae viability, followed by another 5 months of daily minocycline for overall efficacy and persistence of clinical and antibacterial effects. Subsequently, the patients were given standard WHO/MDT chemotherapy for multibacillary leprosy. Clinical improvement was recognizable during the first month, occurring much earlier among those on minocycline 200 mg daily than those who received minocycline 100 mg daily. A similar change also was observed in one patient 11 days after three daily doses of 100 mg of minocycline. At the end of 6 months, all patients were clinically improved with a slight reduction in the average bacterial index (BI) and logarithmic index of bacilli in biopsy (LIB). The effects of minocycline on viability by mouse foot pad inoculation and palmitic acid oxidation assays were noted beginning at 10 to 14 days of daily dosing and becoming more definite after 30 days of treatment. Both tests correlated fairly well. Doses of 200 mg daily did not appear to be more efficient than minocycline 100 daily. Phenolic glycolipid-I (PGL-I) antigen determinations done on some patients during the first month remained positive and did not correlate with changes in viability results. At the end of 6 months, after 5 months of 100 mg of minocycline monotherapy, no viable organisms could be demonstrated by mouse foot pad inoculation and palmitic acid oxidation assays; assays for PGL-I antigen were all negative.(ABSTRACT TRUNCATED AT 250 WORDS)

GM-CSF activates regenerative epidermal growth and stimulates keratinocyte proliferation in human skin in vivo

Granulocyte/macrophage-colony-stimulating factor (GM-CSF), an immunomodulator of hematopoietic cells, has also been shown to stimulate human keratinocyte proliferation in vitro and speed healing of wounds in the skin of lepromatous leprosy patients. In this study we have examined the in vivo effects of recombinant human GM-CSF on epidermal keratinocyte proliferation and on expression of proteins marking regenerative epidermal growth. Skin biopsies from GM-CSF injected cutaneous sites were obtained between 1 and 6 d following administration of 7.5 or 15 micrograms of the growth factor. Activation of keratinocyte proliferation, quantified as the expression of the Ki67+ nuclear antigen, was noted 1 d following GM-CSF administration. A regenerative epidermal phenotype, demonstrated by immunohistochemical staining of cellular proteins involucrin, filaggrin, and keratin 16, was similarly noted as early as 1 d following GM-CSF injection. This phenotype persisted as late as 6 d post-injection. These results suggest that GM-CSF injection into human skin induces keratinocyte proliferation as well as regenerative differentiation of the epidermis. To date no other cytokine has been shown to be mitogenic for human keratinocytes both in vivo and in vitro or to alter keratinocyte differentiation along the "alternate" or regenerative pathway.

Cross-sectional assessment of ELISA reactivity in leprosy patients, contacts, and normal population using the semisynthetic antigen natural disaccharide octyl bovine serum albumin (ND-O-BSA) in Cebu, The Philippines

An indirect enzyme-linked immunosorbent assay (ELISA) using natural disaccharide octyl bovine serum albumin (ND-O-BSA) as antigen was used in testing leprosy patients, contacts and a normal population in Cebu, The Philippines, from 1985 to 1989. A total of 1413 persons were studied. The results suggested that ELISA reactivity and the bacterial index (BI) correlate in a general way. In multibacillary (MB) leprosy, positivity ranges from 54.2% to 92.3% among patients with a BI of < 2+ to > 4+ on the Ridley scale, with an overall average of 84.5%. Paucibacillary (PB) leprosy patients have a low degree of reactivity, with only 15.0% ELISA positive. The test is more efficient in detecting MB than PB leprosy. The contacts of MB leprosy showed 6.5% positivity; contacts of PB leprosy, 7.0% positivity. The normal population showed 1.7% positive ELISA or 17 per thousand population, which is very much less than that of the household contacts. However, because the normal population is a much larger population than the household contact population in a community, more new leprosy cases would emanate from it. Leprosy workers are concerned about the transmission of the disease to household contacts. However, for the reason stated above, we should be more concerned with the silent spread of the disease to the normal population in the community.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of polymerase chain reaction amplification of Mycobacterium leprae-specific repetitive sequence in biopsy specimens from leprosy patients

Biopsy specimens were obtained from 102 leprosy patients before chemotherapy and examined by polymerase chain reaction (PCR) using the primers amplifying the 372-bp DNA of a repetitive sequence of Mycobacterium leprae. The PCR results were then compared with bacterial indices (BI) of slit-skin smears and biopsy specimens. The intensities of DNA bands were in general correlated with the numbers of acid-fast bacilli, and even a sample with only one organism gave a PCR positive result. Ten 5-micron sections from each frozen tissue sample were pooled and processed for DNA preparation. PCR was positive for 11 (73.3%) of 15 biopsy specimens with BI of 0 determined for the paraffin sections from the same biopsy samples. PCR also gave positive results for 84 (96.6%) of 87 BI positive biopsy samples. Although the difference in overall results between the two methods was not statistically significant, PCR seemed to have an advantage over microscopic examination in detecting M. leprae in biopsy specimens negative for acid-fast bacilli. Further evaluation of PCR using more specimens from leprosy patients who are bacteriologically negative is warranted to ensure PCR's advantage over the conventional microscopic examination for the diagnosis of leprosy.

Novel responses of human skin to intradermal recombinant granulocyte/macrophage-colony-stimulating factor: Langerhans cell recruitment, keratinocyte growth, and enhanced wound healing

Recombinant granulocyte/macrophage-colony-stimulating factor (rGM-CSF), prepared from Chinese hamster ovary (CHO) cells and Escherichia coli, was administered to 35 patients with the borderline and polar lepromatous forms of leprosy by the intradermal and subcutaneous routes at doses of 7.5-45.0 micrograms/d for 10 d. With each of these doses and routes, increases in the number of circulating eosinophils were noted. After the intradermal injection, the local skin sites demonstrated zones of roughening and micronodularity that appeared within 24-48 h and persisted for more than 6 d. Reinjection of sites led to enhanced areas of epidermal reaction. GM-CSF prepared from CHO cells was a more potent inducer of this effect. GM-CSF given by the subcutaneous route, at higher doses, failed to initiate these changes. At the microscopic level, the epidermis became thickened (+75%) with increased numbers and layers of enlarged keratinocytes. These contained increased numbers of ribosomes and prominent nucleoli, and were imbedded in a looser meshwork of the zona Pellucida. The modified keratinocytes remained MHC class II antigen negative throughout the course of the response. A major change in the dermis was the progressive accumulation of CD1+, Birbeck granule-positive cells. These Langerhans were recognizable at 48 h after intradermal injection and reached maximum numbers by 4 d. During this period the number of epidermal Langerhans cells remained relatively constant. No increment in dermal Langerhans cells occurred when GLM-CSF was injected by the subcutaneous route. No appreciable increase in the numbers of T cells and monocytes was noted, and granulocytes and eosinophils were largely present within the dermal microvasculature. 4-mm punch biopsies taken from injected sites and adjacent controls were compared in terms of the rapidity of wound healing. 22 of 26 sites demonstrated more rapid filling and hemostasis, whereas four were equivalent to controls. We conclude that rGM-CSF, when introduced into the skin, leads to enhanced keratinocyte growth, the selective recruitment of Langerhans cells into the dermis, and enhanced wound healing of the prepared site. There was no evidence of an enhanced cell-mediated response to Mycobacterium leprae, and bacillary numbers remained unchanged.

Detection of phenolic glycolipid-I antigen and antibody in sera from new and relapsed lepromatous patients treated with various drug regimens

Since phenolic glycolipid-I (PGL-I) is an unequivocal marker of Mycobacterium leprae, the antigen has been a good candidate for the serodiagnosis and monitoring the effectiveness of leprosy chemotherapy. As an effort to define the kinetics of the PGL-I antigen and its antibodies in leprosy patients, this study was initiated to examine the serum specimens obtained serially from lepromatous patients under chemotherapy trials. PGL-I was detectable in 64 (94.1%) of 68 new lepromatous (bacterial index, BI = 3.2 to 5.8) and in 26 (78.8%) of 33 relapsed lepromatous patients (BI = 3.0 to 5.3). Meanwhile, virtually all of the new and relapsed patients were strongly seropositive to PGL-I. PGL-I was not detectable in any of the patients about 18 months after chemotherapy was initiated; however, anti-PGL-I reactivity declined by 50% at 2 years and by about 70% at 5 years after chemotherapy regardless of the drug regimens under study. Considering the rapid disappearance of the PGL-I antigen and steady decrease in anti-PGL-I IgM antibodies following chemotherapy, the PGL-I-based serology may be useful for monitoring the effectiveness of treatment, at both the early and late stages, in leprosy patients whose initial sera contain a significant level of PGL-I antigen or antibodies.

Joint chemotherapy trials in lepromatous leprosy conducted in Thailand, the Philippines, and Korea

Chemotherapy trials in lepromatous leprosy using various combinations of existing antileprosy drugs were conducted jointly by Korea, The Philippines, and Thailand. The general objective of these trials was to determine the most effective and practicable regimen or regimens for field application. Lepromatous patients were divided into two groups: Group I was comprised of new, untreated patients infected with dapsone-sensitive Mycobacterium leprae and Group II consisted of relapsed patients with dapsone-resistant disease. Four different regimens were administered to each group for 5 years. Comparison among the regimens was based on antileprotic efficacy, drug safety, acceptability, field practicability, and economic feasibility. No significant differences were noted among the various regimens as judged by the reduction in the bacterial index (BI), clinical response, and change in biopsy index. Toxicity was seen only in the regimens containing prothionamide and rifampin. The regimens were acceptable to the patients and all were found practical for field use. Clofazimine, even in low doses, was found to suppress the frequency and severity of erythema nodosum leprosum. A multidrug regimen effective against both new and relapsed cases of lepromatous leprosy, whether dapsone sensitive or dapsone resistant, is recommended for field use. Given priority, the cost of the regimens is affordable in the three countries.

Evaluation of Mycobacterium leprae antigens in the monitoring of a dapsone-based chemotherapy of previously untreated lepromatous patients in Cebu, Philippines

Thirty-five previously untreated lepromatous patients receiving dapsone-based therapy were monitored throughout their 5-year period of treatment by serology and by pathology. Sequentially collected sera were used to evaluate the usefulness of four Mycobacterium leprae antigens as used in ELISA to monitor the progress of their therapy. ELISA results were compared with each other and with bacterial load over the treatment period and with duration of treatment. The ELISAs, based on the measurement of IgM antibody reactivity to the two neoglycoproteins (NDO and NTO) representing the phenolic glycolipid antigen of M. leprae, were found to be the most effective in monitoring treatment. A whole M. leprae based ELISA was less efficient in monitoring treatment because it failed to measure antibodies in 8 out of 35 patients and because it provided consistently lower values than either NTO or NDO. The ELISA-inhibition test based on the detection of antibodies to a species-specific epitope on the 36 K antigen of M. leprae was less suitable because of persistent reactivity during therapy, consequently resulting in no significant correlation with ELISA reactivities to NTO or NDO.

Influence of Mycobacterium leprae and its soluble products on the cutaneous responsiveness of leprosy patients to antigen and recombinant interleukin 2

Experiments were carried out in the skin of patients with leprosy to examine whether suppressor cell populations either exist in the skin of multibacillary lepromatous leprosy patients, can be activated with antigen, or are induced to emigrate into a cutaneous site from the circulation. For this purpose, purified protein derivative of tuberculin, a delayed-type antigen that generates a cell-mediated immune response, was introduced into the skin alone or with nonviable Mycobacterium leprae bacilli. Areas of induration and the resulting numbers and phenotypes of emigratory cells were not influenced by M. leprae and its products. Further studies examined the ability of M. leprae and its soluble products to modify the cutaneous response to intradermal injection of recombinant interleukin 2 (IL-2), a lymphokine that mimics a cell-mediated response. Neither the simultaneous injection of M. leprae and IL-2, nor the prior injection of M. leprae followed in 2 days by IL-2, nor the prior administration of IL-2 followed in 4 days by M. leprae, into the same skin site, modified the zone of induration generated by IL-2. In addition, the immunocytochemical and histopathological evaluation of biopsy specimens of skin sites showed no difference between sites injected with IL-2 and sites injected with IL-2 and M. leprae. We conclude that suppressor T cells, if they exist, do not influence the gross or microscopic responsiveness of a cell-mediated skin reaction to antigen and IL-2. IL-2 did, however, enhance the responsiveness of skin-test-positive tuberculoid patients and family contacts to M. leprae antigens by a synergistic effect on the zone of induration and local cell accumulation.

Evaluation of Mycobacterium leprae antigens in the serological monitoring of a clofazimine-based chemotherapeutic study of dapsone resistant lepromatous leprosy patients in Cebu, Philippines

Thirty-one dapsone resistant lepromatous leprosy patients receiving clofazimine based therapy were serologically monitored throughout their 5-year period of treatment. Sequentially collected sera were used to examine 4 Mycobacterium leprae antigens to evaluate their usefulness in ELISA's for monitoring the progress of their therapy. The ELISA results were compared with decline in bacterial load over the treatment period and with duration of treatment. In addition the ELISA's were compared with each other. The ELISA's based on the measurement of IgM antibodies to the two neoglycoproteins (NDO and NTO) representing the phenolic glycolipid antigen of M. leprae were found to be the most effective with regard to monitoring treatment. A whole M. leprae based ELISA was less efficient in monitoring treatment because it failed to measure antibodies in 5 out of 31 patients. The ELISA-inhibition test based on the detection of antibodies to a species-specific epitope on the 36 K antigen of M. leprae was less suitable because of persistent reactivity during therapy.

Histochemical study of Erythema nodosum leprosum (ENL) lesions

A histochemical study of ENL lesions was performed on skin biopsies from 14 leproma-tous patients. There was: 1) the presence of moderate amounts of PAS positive diastase resistant materials, acid mucopolysaccharide, neutral fat, phospholipid, aryl sulfatase and acid phosphatase in areas around and away from reactional sites; 2) the presence of slight amounts or complete absence of these materials within areas of acute inflammation. These changes were interpreted as the result of solubilization and leakage of hydrolytic enzymes into the surrounding tissue. A possible role of lysosomal enzymes in the pathogenesis of ENL lesions is discussed.