CD8+ memory T cells have recently been recognized as playing a key role in natural immunity against unrelated viral infections, a phenomenon referred to as "heterologous antiviral immunity." We now provide data that the cellular immunological interactions that underlie such heterologous immunity can play an equally important role in regulating T helper 2 immune responses and protecting mucosal ...

Abstract The biggest challenge in developing a universal influenza vaccine is the extensive antigenic drift. In contrast to humoral immunity, cell-mediated immunity more cross-reactive and can protect against various subtypes drift variants. Our research group has described computationally optimized broadly reactive antigens (COBRA) develop HA-based protective vaccine. However, studies that cha...

Poly-parasitism is common in endemic communities and reactivity of sera from hookworm-infected patients against schistosomular antigens has been reported. Protective cross-immunity between N. americanus and S. mansoni was investigated in NIH and BALB/c mice. Protective resistance to homologous challenge with both parasites was confirmed in this model, however, functional immunity to heterologou...

An increased frequency of rough cultures with associated reductions in mouse virulence was detected after R-factor transmission into strains of Salmonella choleraesuis var. kunzendorf and S. typhimurium. All rough strains tested, with or without R factors, conferred protective immunity against challenge with homologous or heterologous species of Salmonella, some of which contained R factors. Al...

Immunity has been considered one of the most specific of biologic reactions and it has been assumed that an infection induced by one organism within a closely related group does not immunize against another organism of the same group. The recent studies of Weil, Felix, and Olitzki suggest strongly that there is a group immunity between typhoid and enteritidis infections. The results here report...

Hepatitis C virus (HCV) can cause liver disease of variable severity. Expansion of preexisting memory CD8 T cells by cross-reactivity with a new heterologous virus infection has been shown in mice to shape the repertoire of the primary response and to influence virus-related immunopathology. To determine whether this mechanism can influence the course of HCV infection, we analyzed the features ...

The direct effect of the soluble antigens in the homogenate of adult Nematospiroides dubius (AH) on spleen cells from uninfected NIH mice was investigated using a Mishell-Dutton culture system. Parasite antigens were shown to reduce the plaque-forming cell (PFC) response to sheep red blood cells (SRBC) in a dose-dependent manner in vitro. A population of suppressor cells was demonstrated in the...

The role of cell-mediated immunity in defense against pathogenic free-living amoebae was examined. Both the in vitro macrophage inhibition test and the in vivo delayed hypersensitivity test showed responses to both heterologous and homologous antigens, although homologous systems were the most efficient. It is suggested that exposure to nonpathogenic species of free-living amoebae can stimulate...

Immunity to Theileria parva infection in cattle is often parasite stock specific. The antigenic diversity which is expressed at the schizont stage of the parasite together with a wild reservoir of the organism in buffalo has complicated the development of effective disease control by immunization. We have previously shown that about 70% of cattle inoculated with recombinant forms of p67, a spor...