The role of antibody immunity in protection against fungal infections has been uncertain for decades. This is in sharp contrast to bacteria, viruses, and protozoa where antibody immunity is widely acknowledged to contribute to protection. This raises the questions: Do protective antibodies against fungi exist?; Why has it been so difficult to demonstrate conclusively that antibody immunity prot...

This study examines the role of complement components C3 and C5 in innate and adaptive protective immunity to larval Strongyloides stercoralis in mice. Larval survival in naive C3(-/-) mice was increased as compared with survival in wild-type mice, whereas C3aR(-/-) and wild-type mice had equivalent levels of larval killing. Larval killing in naive mice was shown to be a coordinated effort betw...

Besides their role as building blocks of protein, there are growing evidences that some amino acids have roles in regulating key metabolic pathways that are necessary for maintenance, growth, reproduction, and immunity. Here, we evaluated the modulatory functions of several amino acids in protective immunity against mucosal infection of herpes simplex virus type 1 (HSV-1). We found that glutami...

Important to malaria vaccine design is the phenomenon of "strain-specific" immunity. Using an accurate and sensitive assay of parasite genotype, real-time quantitative PCR, we have investigated protective immunity against mixed infections of genetically distinct cloned "strains" of the rodent malaria parasite Plasmodium chabaudi chabaudi in mice. Four strains of P. c. chabaudi, AS, AJ, AQ, and ...

BACKGROUND Scrub typhus is an acute febrile disease caused by Orientia tsutsugamushi infection. Recently, the rapid increase of scrub typhus incidence in several countries within the endemic region has become a serious public health issue. Despite the wide range of preventative approaches that have been attempted in the past 70 years, all have failed to develop an effective prophylactic vaccine...

Intracellular pathogens are capable of inducing vigorous CD8+ T cell responses. However, we do not entirely understand the factors driving the generation of large pools of highly protective memory CD8+ T cells. Here, we studied the generation of endogenous ovalbumin-specific memory CD8+ T cells following infection with recombinant vesicular stomatitis virus (VSV) and Listeria monocytogenes (LM)...

Sterile protection against malaria infection can be achieved by the inoculation of intact sporozoites while treating concomitantly with the 4-aminoquinoline chloroquine. We present an analysis of protective immunity elicited by successive immunization with Plasmodium berghei sporozoites under chemoprophylaxis. Immunization resulted in a protective, stage-specific immune response. Protection app...

The prevention of bacterial infections via immunization presents particular challenges. While outer membrane extracts are often protective, they are difficult and expensive to isolate and standardize and thus are often impractical for development and implementation in vaccination programs. In contrast, individual proteins, which are easily adapted for use in subunit vaccines, tend to be poorly ...

Leishmania major parasites lacking the GDP-mannose transporter, termed Deltalpg2 parasites, fail to induce disease in mice but persist long-term. We previously found that Deltalpg2 organisms protect BALB/c mice from virulent L. major challenge. In contrast, we report here that Deltalpg2 parasites induce protective immunity in C57BL/6 mice only when administered with CpG-containing oligodeoxynuc...

The irradiated-sporozoite vaccine elicits sterile immunity against Plasmodium parasites in experimental rodent hosts and human volunteers. Based on rodent malaria models, it has been proposed that CD8+ T cells are the key protective effector mechanism required in sporozoite-induced immunity. To investigate the role of class II-restricted immunity in protective immunity, we immunized beta2-micro...