Cryptococcus neoformans is an opportunistic fungal pathogen that causes life-threatening pneumonia and meningoencephalitis in immune compromised individuals. Previous studies have shown that immunization of BALB/c mice with an IFN-γ-producing C. neoformans strain, H99γ, results in complete protection against a second pulmonary challenge with an otherwise lethal cryptococcal strain. The current study evaluated local anamnestic cell-mediated immune responses against pulmonary cryptococcosis in mice immunized with C. neoformans strain H99γ compared to mice immunized with heat-killed C. neoformans (HKC.n.). Mice immunized with C. neoformans strain H99γ had significantly reduced pulmonary fungal burden post-secondary challenge compared to mice immunized with HKC.n. Protection against pulmonary cryptococcosis was associated with increased pulmonary granulomatous formation and leukocyte infiltration followed by a rapid resolution of pulmonary inflammation, which protected the lungs from severe allergic bronchopulmonary mycosis (ABPM)-pathology that developed in the lungs of mice immunized with HKC.n. Pulmonary challenge of interleukin (IL)-4 receptor, IL-12p40, IL-12p35, IFN-γ, T cell and B cell deficient mice with C. neoformans strain H99γ demonstrated a requirement for Th1-type T cell-mediated immunity, but not B cell-mediated immunity, for the induction of H99γ-mediated protective immune responses against pulmonary C. neoformans infection. CD4+ T cells, CD11c+ cells, and Gr-1+ cells were increased in both proportion and absolute number in protected mice. In addition, significantly increased production of Th1-type/pro-inflammatory cytokines and chemokines, and conversely, reduced Th2-type cytokine production was observed in the lungs of protected mice. Interestingly, protection was not associated with increased production of cytokines IFN-γ or TNF-α in lungs of protected mice. In conclusion, immunization with C. neoformans strain H99γ results in the development of protective anti-cryptococcal immune responses that may be measured and subsequently used in the development of immune-based therapies to combat pulmonary cryptococcosis.

Cryptococcus neoformans is an opportunistic fungal pathogen that can cause life-threatening meningoencephalitis in immune compromised patients. Previous, studies in our laboratory have shown that prior exposure to an IFN-γ-producing C. neoformans strain (H99γ) elicits protective immunity against a second pulmonary C. neoformans challenge. Here, we characterized the antibody response produced in mice protected against experimental pulmonary C. neoformans infection compared to non-protected mice. Moreover, we evaluated the efficacy of using serum antibody from protected mice to detect immunodominant C. neoformans proteins. Protected mice were shown to produce significantly more C. neoformans-specific antibodies following a second experimental pulmonary cryptococcal challenge compared to non-protected mice. Immunoblot analysis of C. neoformans proteins resolved by 2-DE using serum from non-protected mice failed to show any reactivity. In contrast, serum from protected mice was reactive with several cryptococcal protein spots. Analysis of these spots by capillary HPLC-ESI-MS/MS identified several cryptococcal proteins shown to be associated with the pathogenesis of cryptococcosis. Our studies demonstrate that mice immunized with C. neoformans strain H99γ produce antibodies that are immune reactive against specific cryptococcal proteins that may provide a basis for the development of immune based therapies that induce protective anti-cryptococcal immune responses.

Toxoplasmosis is an infrequent infection in solid organ transplantation, except in heart transplantation, where the grafting of a positive organ in a negative recipient transmits the infection in a high percentage of cases, in the absence of prophylaxis. We report a case of pneumonia by Toxoplasma gondii in a woman who received a liver transplant and had pre-transplant positive serology. Diagnosis was made by cytologic examination of bronchoalveolar lavage fluid, where the parasite was observed with hematoxylin-eosin and Giemsa staining. That finding was confirmed by direct immunofluorescence and positive polymerase chain reaction. The patient had a favorable outcome, although she had not initially received first-choice drugs. This was a case of severe illness secondary to reactivation of Toxoplasma infection, diagnosed pre-mortem and with a favorable outcome. Duration of treatment and need for secondary prophylaxis in these patients are discussed in the literature. Although infrequent, toxoplasmosis must be considered among the differential diagnoses of pulmonary infiltrates in solid organ transplantation.

Catastrophic antiphospholipid syndrome (CAPS) is an acutely devastating situation characterized by widespread thrombotic microangiopathy in the presence of elevated titers of antiphospholipid antibodies. We describe a 57-year old woman who underwent liver transplantation for primary sclerosing cholangitis and developed this malignant variant of the antiphospholipid syndrome.