Humans show remarkable variation in vulnerability to infection by HIV-1 and especially in the clinical outcomes after infection. Understanding why some people establish and maintain effective control of HIV-1 and others do not is a priority in the effort to (A) By using the HIV-1 exposed but seronegative (HESN) samples as controls, the comparison was carried out between the HIV-1 patients and the HIV-1 exposed but seronegative (HESN) samples under the genotypic risk model of 5/5 vs. other genotypes. (B) By using the HIV-1 exposed but seronegative (HESN) samples as controls, the comparison was carried out between the HIV-1 patients and the HIV-1 exposed but seronegative (HESN) samples under the allelic risk model of 5-repeat allele vs. other alleles. doi:10.1371/journal.pone.0042972.g004 develop new treatments for HIV/AIDS. To our knowledge, this is the first meta-analysis to assess the relationship between the DC-SIGNR VNTR polymorphism and HIV-1 infection risk. Our results showed that the 5/5 homozygous genotype was associated with resistance to HIV-1 in HIV-1 exposed seronegative subjects (HESN), especially in the Asian population. Future studies in different ethnic populations and with clear infection routes should be performed to evaluate these associations. Table S1 The breakdown of HESN controls in the included studies of this meta-analysis according the routine of exposure. (DOC)  Toll-like receptors are critical for clearance of Brucella and play different roles in development of adaptive immunity following aerosol challenge in mice Brucella spp. cause undulant fever in humans and brucellosis in variety of other animals. Both innate and adaptive immunity have been shown to be important in controlling Brucella infection. Toll-like receptors (TLRs) represent a group of pattern recognition receptors (PRRs) that play critical roles in the host innate immune response, as well as development of adaptive immunity. In the current report, we investigated the role of TLR signaling in the clearance of Brucella and development of adaptive immunity in TLR2(−/−), TLR4(−/−), or MyD88(−/−) mice following aerosol exposure to B. melitensis 16 M. Consistent with previous reports, MyD88 is required for efficient clearance of Brucella from all three organs (lung, spleen, and liver). The results reveal Th2-skewed immune responses in TLR2(−/−) mice late in infection and support a TLR2 requirement for efficient clearance of Brucella from the lungs, but not from the spleen or liver. Similarly, TLR4 is required for efficient clearance of Brucella from the lung, but exhibits a minor contribution to clearance from the spleen and no demonstrable contribution to clearance from the liver. Lymphocyte proliferation assays suggest that the TLRs are not involved in the development of cell-mediated memory response to Brucella antigen. Antibody detection reveals that TLR2 and 4 are required to generate early antigen-specific IgG, but not during the late stages of infection. TLR2 and 4 are only transiently required for IgM production and not at all for IgA production. In contrast, MyD88 is essential for antigen specific IgG production late in infection, but is not required for IgM generation over the course of infection. Surprisingly, despite the prominent role for MyD88 in clearance from all tissues, MyD88-knockout mice express significantly higher levels of serum IgA. These results confirm the important role of MyD88 in controlling infection in the spleen while providing evidence of a prominent contribution to protection in other tissues. In addition, although TLR4 and TLR2 contribute little to control of spleen infection, a significant contribution to clearance of lung infection is described. The genus Brucella is a group of Gram-negative, facultative intracellular bacteria that cause brucellosis, a reproductive disease in ruminants, and undulating fever in humans. Brucellosis is one of the most important worldwide zoonotic diseases. Ten species have been identified to date, three of which, including B. melitensis, B. abortus, and B. suis are virulent in humans and represent a significant threat to public health (Atluri et al., 2011) . Humans often become infected following inhalation of particles carrying the bacteria or consumption of dairy products contaminated with the organism. Although vaccination is used to successfully reduce the spread of disease, the risk remains high in underdeveloped nations. There are currently no vaccines available that are safe for use in humans, and although generally effective, antibiotic treatments do not always prevent disease recrudescence. As a result of these factors and concern over their potential weaponization, NIH and the CDC/USDA have classified these three species as category B agents.