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.

A Novel Therapeutic and Prophylactic Vaccine against Tuberculosis Using the Cynomolgus Monkey Model and Mouse Model

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 remarkable protective efficacy in mouse model compared to the BCG. This vaccine also provided therapeutic efficacy against multi-drug resistant TB (MDR-TB) and extremely drug resistant TB (XDR-TB) in murine models. 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 BCG prime and HSP65 + IL-12/HVJ vaccine (boost) by the prime-boost method showed a synergistic prophylactic effect in the monkey. Furthermore, this vaccine exerted therapeutic efficacy (100% survival) and augmentation of immune responses in the TB-infected monkeys.HVJ-Envelope/HSP65 DNA + IL-12 DNA vaccine increased the body weight of TB-infected monkeys, improved the ESR, and augmented the immuneresponses (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. 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.

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.

A Novel Therapeutic and Prophylactic Vaccine (HVJ-Envelope / Hsp65 DNA + IL-12 DNA) against Tuberculosis Using the Cynomolgus Monkey Model

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). An IL-12 expression vector (IL-12DNA) encoding single-chain IL-12 proteins comprised of p40 and p35 subunits were constructed. This vaccine provided remarkable protective efficacy in mouse and guinea pig models compared to the BCG vaccine on the basis of C.F.U of number of TB, survival, an induction of the CD8 positive CTL activity and improvement of the histopathological tuberculosis lesions. This vaccine also provided therapeutic efficacy against multi-drug resistant TB (MDR-TB) and extremely drug resistant TB (XDR-TB) (prolongation of survival time and the decrease in the number of TB in the lung) in murine models. 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. All monkeys in the control group (saline) died within 8 months, while 50% of monkeys in the HSP65+hIL-12/HVJ group survived more than 14 months post-infection (the termination period of the experiment). Furthermore, the BCG priming and HSP65 + IL-12/HVJ vaccine (booster) by the priming-booster method showed a synergistic effect in the TB-infected cynomolgus monkey (100% survival). In contrast, 33% of monkeys from BCG Tokyo alone group were alive (33% survival). Furthermore, this vaccine exerted therapeutic efficacy (100% survival) and augmentation of 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.

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.

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.

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.

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.