HIV-specific serum IgG levels were measured 2 (A, B) and 4 wk (C, D) post-vaccination with HIV antigen-ELISA using p24Gag (A, C) and gp160Env (B, D) as coating antigens, as described in Materials and Methods

HIV-specific serum IgG levels were measured 2 (A, B) and 4 wk (C, D) post-vaccination with HIV antigen-ELISA using p24Gag (A, C) and gp160Env (B, D) as coating antigens, as described in Materials and Methods. experiments.(TIF) pone.0041205.s002.tif (63K) GUID:?E0BC8992-66A0-4818-8129-D4A09A19B7D8 Abstract Tuberculosis (TB) has emerged as the most prominent bacterial disease found in human immunodeficiency virus (HIV)-positive individuals worldwide. Due to high prevalence of asymptomatic (infection. The impact of concurrent infection on the immunogenicity of a HIV vaccine candidate, MultiHIV DNA/protein, was investigated in mice. We found that, depending on the vaccination route, mice infected with before the administration of the HIV vaccine showed impairment in both the magnitude and the quality of antibody and T cell responses to the vaccine components p24Gag and gp160Env. Mice infected with prior to intranasal HIV vaccination exhibited reduced p24Gag-specific serum IgG and IgA, and suppressed gp160Env-specific serum IgG as compared to respective titers in uninfected HIV-vaccinated controls. Importantly, in had fewer p24Gag-specific IFN–expressing T cells and multifunctional T cells in their spleens. These results suggest that infection might interfere with the outcome of prospective HIV vaccination in humans. Introduction Despite recent advances in highly active anti-retroviral therapy, human immunodeficiency virus (HIV) infections and the resulting acquired immunodeficiency syndrome (AIDS) remain an important cause of morbidity and mortality worldwide with 2.6 million new cases and 1.8 million deaths reported in 2009 2009 [1]. Therefore, it is widely acknowledged that a safe and effective HIV prophylactic vaccine would be the best long-term measure to bring the HIV/AIDS epidemics under control. It has been suggested that the effectiveness of vaccines in the population is affected by several factors such as age [2], malnutrition [3], and concurrent infections [4]C[9]. One of the factors that could potentially affect HIV vaccination efficacy is high prevalence of tuberculosis (TB) in HIV endemic regions. Over 90% of the worlds HIV/AIDS cases are in Africa where TB is the leading cause of HIV-related mortality [10]. The HIV and TB epidemics fuel each other [11] and the relationship between HIV and (infection is activated by HIV-induced immunodeficiency and latent HIV in proviral form is triggered by TB-induced immune activation [12], [13]. In addition, TB impairs recovery of immune system in HIV-infected patients undergoing anti-retroviral therapy [14]. Studies of long-term non-progressors, a small subset of HIV-1 infected individuals who have stable CD4 T cell counts for more than 5 years without retroviral therapy [15], firmly suggest that an effective immune response helps control the infection and FOXO4 disease. These studies imply that, by analogy to natural HIV infection in long-term non-progressors, an efficient HIV vaccine should elicit cytotoxic T cell responses [16], and multifunctional T cells that produce multiple cytokines in response to HIV antigens SCH 442416 [17]. In addition to cell-mediated immunity, the HIV vaccine should evoke early and robust broadly virus-neutralizing antibodies [18] similar to those identified in a subset of HIV-1 infected subjects [19]. It is also considered important that, in order to prevent the infection or reduce the infectious inoculum, the HIV vaccine should induce immune responses at mucosal surfaces, which represent sites of HIV entry [20], [21]. An extensive search for a HIV vaccine has resulted in a large number of vaccine candidates that in laboratory animals elicited immune responses against HIV antigens [22]. Based on results of immunogenicity and protection studies in non-human primates several promising HIV vaccine candidates were taken to clinical trials. To date, out of several vaccine candidates investigated in clinical phase II/III trials, only one showed moderate level of protective efficacy. Thus, although level of protection afforded by this vaccine was unsatisfactory, the trial demonstrated that construction of an effective HIV vaccine is possible [23]. Nevertheless, future HIV vaccine studies should, in addition to defining protective immune responses, also focus on factors that could interfere with vaccine-induced protection. One of the overlooked issues that have potential impact on HIV vaccine development stems from the fact that geographical areas with the highest prevalence of HIV and infections overlap. Consequently, future HIV vaccine will often be administered to individuals harboring latent or undiagnosed active TB. Several acute or chronic infections, such as measles, malaria, and helminthes have previously been found to interfere with efficacy of vaccination against unrelated pathogens [4]C[9]. In contrast, the impact of TB on HIV vaccine efficacy has not yet been addressed in preclinical studies, despite the high prevalence of TB in HIV vaccine target populations. In this study we investigated the effect of concurrent chronic infection on immunogenicity of a HIV DNA/protein vaccine candidate that has generated promising results in a mouse model [24]. We found that both SCH 442416 the magnitude and the quality of antibody and T cell responses to such vaccine were impaired by infection. Results Concurrent Infection Impairs IgA Levels Induced by the HIV Vaccination The humoral response mediated by IgA at mucosal surfaces may help prevent HIV infection SCH 442416 or reduce the viral load [20]. We therefore assessed the impact of ongoing infection on.