A simple and economic three-step process for producing highly purified Fab' fragments directly from the egg yolk water-soluble fraction.

Although mammals are still the main source of polyclonal antibodies production, the use of egg yolk immunoglobulins (IgY) is increasing, and thus improvement of its safety to reduce undesired reactions is needed. Removal of IgY constant domains by pepsin enzymatic treatment is expected to reduce potential adverse effects derived from the parenteral administration of these antibodies, while also increasing its distribution volume. Current Fab' production requires the previous purification of IgY to be used as starting material.

Critical aspects on traditional antivenom production processes and their optimization by factorial analysis.

Most antivenoms are produced by techniques developed over 50 years ago, with minor modifications. Herein we revise the core of traditional antivenom production processes aiming to optimize key determinants for both consistent antivenom production and the best balance between F(ab')2 quality and recovery. Factorial design analysis revealed that pepsin digestion of 1:3 saline diluted equine plasma for 60 min under pH: 3.

Baculovirus capsid display in vaccination schemes: effect of a previous immunity against the vector on the cytotoxic response to delivered antigens.

The baculovirus Autographa californica multiple nuclear polyhedrosis virus (AcMNPV) infects lepidopteran invertebrates as natural hosts, although it also has been used as display vector for vaccine development. In this work, we evaluated the effectiveness of repetitive doses of AcMNPV-based vectors on the cytotoxic immune response specific to the capsid-displayed heterologous antigen ovalbumin (OVA). Our results demonstrate that baculovirus vectors induce a boosting effect in the cytotoxic immune response to OVA, making possible to recover the levels obtained in the primary response.

The localization of a heterologous displayed antigen in the baculovirus-budded virion determines the type and strength of induced adaptive immune response.

In the search of strategies of presentation of heterologous antigens to elicit humoral or cellular immune responses that modulate and properly potentiate each type of response, researchers have been studying baculovirus (BV) as vaccine vectors with promising results. For some years, several research groups explored different antigen presentation approaches using the BV AcNPV by expressing polypeptides on the surface of budded virions or by de novo synthesis of heterologous antigens by transduction of mammalian cells. In the case of expression on the surface of budded virions, for example, researchers have expressed polypeptides in peplomers as GP64 glycoprotein fusions or distributed throughout the entire surface by fusions to portions of the G protein of vesicular stomatitis virus, VSV.

Two Distinctive Phenotypes of AcMNPV Display Different Immune Abilities and Intracellular Destiny.

The budded phenotype (BV) of the baculovirus AcMNPV has been demonstrated to have strong immunostimulatory properties that are relevant for the development of vaccines and antiviral therapies. Although the occluded phenotype (ODV) shares the main structural proteins and its genome with BV, it has been poorly studied in mammals. In this study, we assessed the capacity of ODV to induce immune responses in mice.