NOX2-Derived Reactive Oxygen Species Control Inflammation during Leishmania amazonensis Infection by Mediating Infection-Induced Neutrophil Apoptosis.

Reactive oxygen species (ROS) produced by NADPH phagocyte oxidase isoform (NOX2) are critical for the elimination of intracellular pathogens in many infections. Despite their importance, the role of ROS following infection with the eukaryotic pathogen Leishmania has not been fully elucidated. We addressed the role of ROS in C57BL/6 mice following intradermal infection with Leishmania amazonensis. Despite equivalent parasite loads compared with wild-type (WT) mice, mice deficient in ROS production by NOX2 due to the absence of the gp91 subunit (gp91phox-/-) had significantly more severe pathology in the later stages of infection. Pathology in gp91phox-/- mice was not associated with alterations in CD4+ T cell-mediated immunity but was preceded by enhanced neutrophil accumulation at the dermal infection site. Ex vivo analysis of infected versus uninfected neutrophils revealed a deficiency in infection-driven apoptosis in gp91phox-/- mice versus WT mice. gp91phox-/- mice presented with higher percentages of healthy or necrotic neutrophils but lower percentages of apoptotic neutrophils at early and chronic time points. In vitro infection of gp91phox-/- versus WT neutrophils also revealed reduced apoptosis and CD95 expression but increased necrosis in infected cells at 10 h postinfection. Provision of exogenous ROS in the form of H2O2 reversed the necrotic phenotype and restored CD95 expression on infected gp91phox-/- neutrophils. Although ROS production is typically viewed as a proinflammatory event, our observations identify the importance of ROS in mediating appropriate neutrophil apoptosis and the importance of apoptosis in inflammation and pathology during chronic infection.

[High frequency of dyslipidemia in VIH-infected patients in aa peruvian public hospital]. / Elevada frecuencia disclipidemia en pacientes infectados por VIH en un Hospital público peruano.

The objective of the study was to determine the frequency and characteristics of dyslipidemia in patients with HIV in highly active antiretroviral therapy (HAART) in a Peruvian public hospital. A cross-sectional study was carried out in patients with complete lipid profile after receiving at least six months of HAART. Dyslipidemia was defined according to the criteria of the NCEP-ATP III. We reviewed 2 975 clinical histories, and included 538 (18.1%) in the analysis. The frequency of dyslipidemia was 74.7%. HAART regimens which include protease inhibitors (PI) (odds ratio [OR]: 1.22; confidence interval at 95% [CI 95%]: 1.11-1.33) and to be older than 40 years (OR: 1.17; CI 95%: 1.05-1.28) were associated with dyslipidemia, adjusted by viral load, CD4 lymphocyte level and gender. In conclusion, dyslipidemia was very common in our sample and was mainly associated with the use of PI. It is necessary to promote the dyslipidemia control as part of the comprehensive care of the patient with HIV.

El objetivo del estudio fue determinar la frecuencia y características de la dislipidemia en pacientes con VIH en terapia antirretroviral de gran actividad (TARGA) en un hospital público peruano. Se realizó un estudio transversal en pacientes que tuvieran un perfil lipídico completo luego de recibir al menos seis meses de TARGA. La dislipidemia se definió según los criterios NCEP-ATP III. Se revisaron 2975 historias clínicas, 538 (18.1%) fueron incluidas en el análisis. La frecuencia de dislipidemia fue 74.7%. Los esquemas de TARGA que incluían inhibidores de la proteasa (IP) (OR 1.22; IC95% 1,11-1,34) y la edad mayor de 40 años (OR 1.17; IC95% 1,06-1,29) mostraron asociación con dislipidemia, ajustado por carga viral, nivel de células CD4 y sexo. En conclusión, la dislipidemia fue muy frecuente en la muestra estudiada y estuvo asociada principalmente al uso de IP. Es necesario promover el control de la dislipidemia como parte de la atención integral del paciente con infección por VIH.

Divergent roles for Ly6C+CCR2+CX3CR1+ inflammatory monocytes during primary or secondary infection of the skin with the intra-phagosomal pathogen Leishmania major.

Inflammatory monocytes can be manipulated by environmental cues to perform multiple functions. To define the role of monocytes during primary or secondary infection with an intra-phagosomal pathogen we employed Leishmania major-red fluorescent protein (RFP) parasites and multi-color flow cytometry to define and enumerate infected and uninfected inflammatory cells in the skin. During primary infection, infected monocytes had altered maturation and were the initial mononuclear host cell for parasite replication. In contrast, at a distal site of secondary infection in mice with a healed but persistent primary infection, this same population rapidly produced inducible nitric oxide synthase (iNOS) in an IFN-γ dependent manner and was critical for parasite killing. Maturation to a dendritic cell-like phenotype was not required for monocyte iNOS-production, and enhanced monocyte recruitment correlated with IFN-γ dependent cxcl10 expression. In contrast, neutrophils appeared to be a safe haven for parasites in both primary and secondary sites. Thus, inflammatory monocytes play divergent roles during primary versus secondary infection with an intra-phagosomal pathogen.

Elevada frecuencia de dislipidemia en pacientes infectados por VIH en un hospital público peruano / High frequency of dyslipidemia in HIV-infected patients in a peruvian public hospital

El objetivo del estudio fue determinar la frecuencia y características de la dislipidemia en pacientes con VIH en terapia antirretroviral de gran actividad (TARGA) en un hospital público peruano. Se realizó un estudio transversal en pacientes que tuvieran un perfil lipídico completo luego de recibir al menos seis meses de TARGA. La dislipidemia se definió según los criterios NCEP-ATP III. Se revisaron 2975 historias clínicas, 538 (18.1%) fueron incluidas en el análisis. La frecuencia de dislipidemia fue 74.7%. Los esquemas de TARGA que incluían inhibidores de la proteasa (IP) (OR 1.22; IC95% 1,11-1,34) y la edad mayor de 40 años (OR 1.17; IC95% 1,06-1,29) mostraron asociación con dislipidemia, ajustado por carga viral, nivel de células CD4 y sexo. En conclusión, la dislipidemia fue muy frecuente en la muestra estudiada y estuvo asociada principalmente al uso de IP. Es necesario promover el control de la dislipidemia como parte de la atención integral del paciente con infección por VIH.

The objective of the study was to determine the frequency and characteristics of dyslipidemia in patients with HIV in highly active antiretroviral therapy (HAART) in a Peruvian public hospital. A cross-sectional study was carried out in patients with complete lipid profile after receiving at least six months of HAART. Dyslipidemia was defined according to the criteria of the NCEP-ATP III. We reviewed 2 975 clinical histories, and included 538 (18.1%) in the analysis. The frequency of dyslipidemia was 74.7%. HAART regimens which include protease inhibitors (PI) (odds ratio [OR]: 1.22; confidence interval at 95% [CI 95%]: 1.11-1.33) and to be older than 40 years (OR: 1.17; CI 95%: 1.05-1.28) were associated with dyslipidemia, adjusted by viral load, CD4 lymphocyte level and gender. In conclusion, dyslipidemia was very common in our sample and was mainly associated with the use of PI. It is necessary to promote the dyslipidemia control as part of the comprehensive care of the patient with HIV.

Cutaneous Infection with Leishmania major Mediates Heterologous Protection against Visceral Infection with Leishmania infantum.

Visceral leishmaniasis (VL) is a fatal disease of the internal organs caused by the eukaryotic parasite Leishmania. Control of VL would best be achieved through vaccination. However, this has proven to be difficult partly because the correlates of protective immunity are not fully understood. In contrast, protective immunity against nonfatal cutaneous leishmaniasis (CL) is well defined and mediated by rapidly recruited, IFN-γ-producing Ly6C(+)CD4(+) T cells at the dermal challenge site. Protection against CL is best achieved by prior infection or live vaccination with Leishmania major, termed leishmanization. A long-standing question is whether prior CL or leishmanization can protect against VL. Employing an intradermal challenge model in mice, we report that cutaneous infection with Leishmania major provides heterologous protection against visceral infection with Leishmania infantum. Protection was associated with a robust CD4(+) T cell response at the dermal challenge site and in the viscera. In vivo labeling of circulating cells revealed that increased frequencies of IFN-γ(+)CD4(+) T cells at sites of infection are due to recruitment or retention of cells in the tissue, rather than increased numbers of cells trapped in the vasculature. Shortly after challenge, IFN-γ-producing cells were highly enriched for Ly6C(+)T-bet(+) cells in the viscera. Surprisingly, this heterologous immunity was superior to homologous immunity mediated by prior infection with L. infantum. Our observations demonstrate a common mechanism of protection against different clinical forms of leishmaniasis. The efficacy of leishmanization against VL may warrant the introduction of the practice in VL endemic areas or during outbreaks of disease.

Site-dependent recruitment of inflammatory cells determines the effective dose of Leishmania major.

The route of pathogen inoculation by needle has been shown to influence the outcome of infection. Employing needle inoculation of the obligately intracellular parasite Leishmania major, which is transmitted in nature following intradermal (i.d.) deposition of parasites by the bite of an infected sand fly, we identified differences in the preexisting and acute cellular responses in mice following i.d. inoculation of the ear, subcutaneous (s.c.) inoculation of the footpad, or inoculation of the peritoneal cavity (intraperitoneal [i.p.] inoculation). Initiation of infection at different sites was associated with different phagocytic populations. Neutrophils were the dominant infected cells following i.d., but not s.c. or i.p., inoculation. Inoculation of the ear dermis resulted in higher frequencies of total and infected neutrophils than inoculation of the footpad, and these higher frequencies were associated with a 10-fold increase in early parasite loads. Following inoculation of the ear in the absence of neutrophils, parasite phagocytosis by other cell types did not increase, and fewer parasites were able to establish infection. The frequency of infected neutrophils within the total infected CD11b(+) population was higher than the frequency of total neutrophils within the total CD11b(+) population, demonstrating that neutrophils are overrepresented as a proportion of infected cells. Employing i.d. inoculation to model sand fly transmission of parasites has significant consequences for infection outcome relative to that of s.c. or i.p. inoculation, including the phenotype of infected cells and the number of parasites that establish infection. Vector-borne infections initiated in the dermis likely involve adaptations to this unique microenvironment. Bypassing or altering this initial step has significant consequences for infection.