Comparative Innate and Adaptive Immune Responses in Atlantic Bottlenose Dolphins (Tursiops truncatus) With Viral, Bacterial, and Fungal Infections.

Free-ranging Atlantic bottlenose dolphins (n = 360) from two southeastern U.S. estuarine sites were given comprehensive health examinations between 2003 and 2015 as part of a multi-disciplinary research project focused on individual and population health. The study sites (and sample sizes) included the Indian River Lagoon (IRL), Florida, USA (n = 246) and Charleston harbor and associated rivers (CHS), South Carolina, USA (n = 114). Results of a suite of clinicoimmunopathologic tests revealed that both populations have a high prevalence of infectious and neoplastic disease and a variety of abnormalities of their innate and adaptive immune systems. Subclinical infections with cetacean morbillivirus and Chlamydiaceae were detected serologically. Clinical evidence of orogenital papillomatosis was supported by the detection of a new strain of dolphin papillomavirus and herpesvirus by molecular pathology. Dolphins with cutaneous lobomycosis/lacaziasis were subsequently shown to be infected with a novel, uncultivated strain of Paracoccidioides brasiliensis, now established as the etiologic agent of this enigmatic disease in dolphins. In this review, innate and adaptive immunologic responses are compared between healthy dolphins and those with clinical and/or immunopathologic evidence of infection with these specific viral, bacterial, and fungal pathogens. A wide range of immunologic host responses was associated with each pathogen, reflecting the dynamic and complex interplay between the innate, humoral, and cell-mediated immune systems in the dolphin. Collectively, these studies document the comparative innate and adaptive immune responses to various types of infectious diseases in free-ranging Atlantic bottlenose dolphins. Evaluation of the type, pattern, and degree of immunologic response to these pathogens provides novel insight on disease immunopathogenesis in this species and as a comparative model. Importantly, the data suggest that in some cases infection may be associated with subclinical immunopathologic perturbations that could impact overall individual and population health.

DNAhsp65 Vaccine as Therapy against Paracoccidioidomycosis.

The conventional treatment for fungal diseases usually shows long periods of therapy and the high frequency of relapses and sequels. New strategies of the treatment are necessary. We have shown that the Mycobacterium leprae HSP65 gene can be successfully used as therapy against murine Paracoccidioidomycosis (PCM). Here, we described the methodology of DNAhsp65 immunotherapy in mice infected with the dimorphic fungus Paracoccidioides brasiliensis, one of PCM agent, evaluating cytokines levels, fungal burden, and lung injury. Our results provide a new prospective on the immunotherapy of mycosis.

Plasmacytoid dendritic cells in cutaneous lesions of patients with chromoblastomycosis, lacaziosis, and paracoccidioidomycosis: a comparative analysis.

Plasmacytoid dendritic cells (pDCs) are characterized by expression of CD123 and BDCA-2 (Blood Dendritic Cell Antigen 2) (CD303) molecules, which are important in innate and adaptive immunity. Chromoblastomycosis (CBM), lacaziosis or Jorge Lobo's disease (JLD), and paracoccidioidomycosis (PCM), are noteworthy in Latin America due to the large number of reported cases. The severity of lesions is mainly determined by the host's immune status and in situ responses. The dendritic cells studied in these fungal diseases are of myeloid origin, such as Langerhans cells and dermal dendrocytes; to our knowledge, there are no data for pDCs. Forty-three biopsies from patients with CBM, 42 from those with JLD and 46 diagnosed with PCM, were evaluated by immunohistochemistry. Plasmacytoid cells immunostained with anti-CD123 and anti-CD303 were detected in 16 cases of CBM; in those stained with anti-CD123, 24 specimens were obtained from PCM. We did not detect the presence of pDCs in any specimen using either antibody in JLD. We believe that, albeit a secondary immune response in PCM and CBM, pDCs could act as a secondary source of important cytokines. The BDCA-2 (CD303) is a c-type lectin receptor involved in cell adhesion, capture, and processing of antigens. Through the expression of the c-lectin receptor, there could be an interaction with fungi, similar to other receptors of this type, namely, CD207 in PCM and CD205 and CD209 in other fungal infections. In JLD, the absence of expression of CD123 and CD303 seems to indicate that pDCs are not involved in the immune response.

Nanobiotechnological approaches to delivery of DNA vaccine against fungal infection.

Vaccines play an essential role in keeping humans healthy. Innovative approaches to their use include the utilization of plasmid DNA encoding sequences to express foreign antigens. DNAhsp65 from Mycobacterium leprae is suitable for this purpose due to its ability to elicit a powerful immune response. Controlled release systems represent a promising approach to delivering vaccines. In this work, we used liposomes or PLGA systems to deliver DNAhsp65 to treat the pulmonary fungal infection Paracoccidioidomycosis. Both formulations modulated a protective immune response and reduced the pulmonary fungal burden even in the groups receiving less than four times the amount of the DNAhps65 entrapped within the nanoparticles. Although both systems had the same effective therapeutic results, the advantage of the liposome formulation was that it was administered intranasally, which may be more easily accepted by patients. These systems are a great alternative to be considered as adjuvant vaccine therapy for systemic mycosis.

DNAhsp65 vaccination induces protection in mice against Paracoccidioides brasiliensis infection.

Heat-shock proteins are molecules with extensive data showing their potential as immunomodulators of different types of diseases. The gene of HSP65 from Mycobacterium leprae has shown prophylactic and immunotherapeutic effects against a broad arrays of experimental models including tuberculosis, leishmaniasis, arthritis and diabetes. With this in mind, we tested the DNAhsp65 vaccine using an experimental model of Paraccocidiodomycosis, an important endemic mycosis in Latin America. The intramuscular immunization with DNAhsp65 induced, in BALB/c mice, an increase of Th1-levels cytokines and a reduction of fungal burdens resulted in a marked reduction of collagen and lung remodeling. DNAhsp65 may be an attractive candidate for prevention, therapy and as an adjuvant for mycosis treatment.