The Route of Leishmania tropica Infection Determines Disease Outcome and Protection against Leishmania major in BALB/c Mice

Leishmania tropica is one of the causative agents of leishmaniasis in humans. Routes of infection have been reported to be an important variable for some species of Leishmania parasites. The role of this variable is not clear for L. tropica infection. The aim of this study was to explore the effects of route of L. tropica infection on the disease outcome and immunologic parameters in BALB/c mice. Two routes were used; subcutaneous in the footpad and intradermal in the ear. Mice were challenged by Leishmani major, after establishment of the L. tropica infection, to evaluate the level of protective immunity. Immune responses were assayed at week 1 and week 4 after challenge. The subcutaneous route in the footpad in comparison to the intradermal route in the ear induced significantly more protective immunity against L. major challenge, including higher delayed-type hypersensitivity responses, more rapid lesion resolution, lower parasite loads, and lower levels of IL-10. Our data showed that the route of infection in BALB/c model of L. tropica infection is an important variable and should be considered in developing an appropriate experimental model for L. tropica infections.

Immunization trial by leishmania treated with Mitomycin-c

Leishmania tropica is a protozoan parasite that causes cutaneous disease in the old world. The study aimed to determine cell-mediated immunity by measuring serum IFN-gamma and IL-4 levels, in BALB/C mice immunized with 107 mitomycin-c treated live leishmania promastigotes [inhl], combined with 2microg IL-12, or immunized with 2 microg IL-12 only[controls], or immunized with 107 wild type leishmania promastigotes. We found that inhl induce significantly higher levels of IFN-gamma 360.62 pg/ml than controls 4.36 pg/ml and then WT 41.72 pg/ml. beside of this, inhl induce significantly lower IL-4 levels 3.18 pg/ml than WT 69.82 pg/ml and then controls [lower than 2pg/ml]. Our study revealed that inhl induce cellular mediated immunity comparable with controls and WT

Study for the immune response against some major antigens of leishmania

Leishmaniasis is condidered to be dispersed in Syria, and because of the side effects that caused by drugs and resistant to them, so the prevention is very important to stop dispersing the disease. For that, our study aimed to evaluate the role of cellular immune response [IFN-gamma] and humoral immune response [IgG] that induced by the total extract of L. tropica or the mixed of 63 and 43 KDa antigens which are taken from the same strain. In this study we used fifteen BALB/c mice divided into three groups. The first was immunized by total extract of L. tropica with incomplete frond adjuvant [IFA], and the second group was immunized with the mixed of two proteins. 43, 63 KDa with IFA, and the control group was inoculated with phosphate saline buffer [PBS]. we observed that each total extract and mixed proteins induce Th1 response and possible Th2 response, but this response was significantly stronger with the mixed proteins p=3.6x10-5 for IFN-gamma titer and p=4.8x10-6 for IgG titer which is considered a positive signal to continue studying to reach to an effective and safe vaccine

Leishmania tropica infection, in comparison to Leishmania major, induces lower delayed type hypersensitivity in BALB/c mice

Leishmania tropica and L. major are etiologic agents of human cutaneous leishmaniasis. Delayed type hypersensitivity (DTH) is an immunologic response that has been frequently used as a correlate for protection against or sensitization to leishmania antigen. In BALB/c mice, L. tropica infection results in non-ulcerating disease, whereas L. major infection results in destructive lesions. In order to clarify the immunologic mechanisms of these 2 different outcomes, we compared the ability of these 2 leishmania species in induction of DTH response in this murine model. BALB/c mice were infected with L. major or L. tropica, and disease evolution and DTH responses were determined. The results show that the primary L. major infection can exacerbate the secondary L. major infection and is associated with DTH response. Higher doses of the primary L. major infection result in more disease exacerbation of the secondary L. major infection as well as higher DTH response. L. tropica infection induces lower DTH responses than L. major. We have previously reported that the primary L. tropica infection induces partial protection against the secondary L. major infection in BALB/c mice. Induction of lower DTH response by L. tropica suggests that the protection induced against L. major by prior L. tropica infection may be due to suppression of DTH response.

Comparison on the performance of Leishmania major-like and Leishmania braziliensis braziliensis as antigen for new world leishmaniasis IgG-immunofluorescence test

O desempenho de um antigeno de promastigotas de L. major-like para o diagnostico sorologico de leishmaniose mucocutanea pelo teste de imunofluorescencia-IgG foi comparado com o desempenho de um antigeno de L. braziliensis braziliensis. Cada antigeno foi usado para testar 224 soros de etiologias como leishmaniose mucocutanea, micoses profundas, toxoplasmose, malaria, doenca de Chagas, leishmaniose visceral, fator anti-nucleo, esquistossomose mansonica, fator reumatoide e controles normais. A concordancia entre as respostas de cada antigeno foi grande: 77,2 por cento dos soros de leishmaniose mostraram resultado positivo para ambos os antigenos ou negativo, assim como 91,1 por cento dos soros controle negativos. Reacoes cruzadas ficaram restritas a doenca de Chagas, leishmaniose visceral, fator anti-nucleo e paracoccidioidomicose. A resposta quantitativa dos soros de leishmaniose e doenca de Chagas foi avaliada pelo metodo de regressao linear; embora a interseccao com o eixo y e o "slope" fossem diferentes para cada antigeno nenhum deles se mostrou melhor na evidenciacao de anticorpos anti-Leishmania. O antigeno de L. major-like mostrou-se melhor que o de L.b. braziliensis na evidenciacao de anticorpos em soros de doenca de Chagas.