Proteins of Leishmania (Viannia) shawi confer protection associated with Th1 immune response and memory generation

<p>Abstract</p> <p>Background</p> <p><it>Leishmania (Viannia) shawi </it>parasite was first characterized in 1989. Recently the protective effects of soluble leishmanial antigen (SLA) from <it>L. (V.) shawi </it>promastigotes were demonstrated using BALB/c mice, the susceptibility model for this parasite. In order to identify protective fractions, SLA was fractionated by reverse phase HPLC and five antigenic fractions were obtained.</p> <p>Methods</p> <p>F1 fraction was purified from L. (V.) shawi parasite extract by reverse phase HPLC. BALB/c mice were immunized once a week for two consecutive weeks by subcutaneous routes in the rump, using 25 μg of F1. After 1 and 16 weeks of last immunization, groups were challenged in the footpad with L. (V.) shawi promastigotes. After 2 months, those same mice were sacrificed and parasite burden, cellular and humoral immune responses were evaluated.</p> <p>Results</p> <p>The F1 fraction induced a high degree of protection associated with an increase in IFN-γ, a decrease in IL-4, increased cell proliferation and activation of CD8⁺T lymphocytes. Long-term protection was acquired in F1-immunized mice, associated with increased CD4⁺central memory T lymphocytes and activation of both CD4⁺and CD8⁺T cells. In addition, F1-immunized groups showed an increase in IgG2a levels.</p> <p>Conclusions</p> <p>The inductor capability of antigens to generate memory lymphocytes that can proliferate and secrete beneficial cytokines upon infection could be an important factor in the development of vaccine candidates against American Tegumentary Leishmaniasis.</p

Neuropsychiatric assessments in patients with multiple sclerosis in early phases and with low disability

Sergio L Schmidt,1,2 Michele Santos da Silva,2 Juliana J Schmidt,2 Ana Lucia Novais Carvalho,3 Claudia Cristina Ferreira Vasconcelos,2 Renata Alves Paes,2 Yolanda EM Boechat,4 Rafael Neder,2 Regina P Alvarenga2 1Department of Neurophysiology, State University of Rio de Janeiro, RJ, Brazil; 2Neurology Department, Federal University of the State of Rio de Janeiro, RJ, Brazil; 3Department&nbsp;of Psychology, Fluminense Federal University, Niteroi, Brazil; 4Department of Internal Medicine, Fluminense Federal University, Niteroi, Brazil Background: In the early phases of multiple sclerosis (MS), patients exhibit slight neuropsychiatric deficits that can only be detected using reliable tools. Aim: The present investigation aimed to examine neuropsychological performance in 35 patients with incipient MS. Patients and methods: For the MS group, the inclusion criteria included time of disease &lt;3&nbsp;years and low disability. The neuropsychological battery consisted of Rey Auditory Learning Test, Controlled Oral Word Association Test, Hooper Visual Organization Test, and Symbol Digit Modalities Test (SDMT). Results: After correction for the educational level, no significant effect of MS on performance was found for all the tests except for the number of errors of the SDMT (NE-SDMT). Higher levels of education were associated with better performances in all tests, except for the NE-SDMT. MS patients made more errors than the controls. Conclusion: The effect on the NE-SDMT may reflect difficulties in the ability to inhibit inadequate responses. Patients may exhibit impulsive control disorders in incipient MS, independent of their educational level. Keywords: processing speed, cognitive impairments, neuropsycholog