In the Western hemisphere, at least five mammarenaviruses cause human viral hemorrhagic fevers with high case fatality rates. Junín virus (JUNV) is the only hemorrhagic fever virus for which transfusion of survivor immune plasma that contains neutralizing antibodies ("passive immunity") is an established treatment. Here, we report the structure of the JUNV surface glycoprotein receptor-binding ...

A group of mice was vaccinated against Type II pneumoccci and subsequently tested for immunity against different numbers of the live bacteria. The immunity tests were conducted within two zones of dosage. In the first zone where the doses were kept within reasonable limits (10(-6) to 10(-3) cc. of culture), the number of invading bacteria was without influence and the occurrence of infections w...

Small areas of skin infiltrated with immune serum proved refractory to the injurious action of a filterable rabbit virus inoculated 24 to 48 hours later. Infiltrations of normal serum did not appreciably protect the skin against the virus. The local protection afforded by the infiltrations of immune serum appears to constitute an example of local passive immunity. Small areas of skin infiltrate...

Exposure to infectious diseases has an unexpected benefit of inhibiting autoimmune diseases and allergies. This is one of many fundamental fitness tradeoffs associated with immune system architecture. The immune system attacks pathogens, but also may (inappropriately) attack the host. Exposure to pathogens can suppress the deleterious response, at the price of illness and the decay of immunity ...

In guinea pigs, when tubercufin sensitivity was passively transferred by lymphoid ceils sensitized to tubercle bacilli and labeled with tritiated thymidine, the transferred ceils were readily identified at the PPD skin test site (1). Further, the transfer of tuberculin sensitivity was not achieved by transferring BCG-sensitized cells enclosed in Millipore chambers (2). In mice, however, when tr...

Immune mechanisms mediating protective immunity against porcine reproductive and respiratory syndrome virus (PRRSV) are not well understood. The PRRSV-specific humoral immune response has been dismissed as being ineffective and perhaps deleterious for the host. The function of PRRSV antibodies in protective immunity against infection with a highly abortifacient strain of this virus was examined...