Viruses that affect Argentinian honey bees (Apis mellifera).

Beekeeping is a widespread activity in Argentina, mainly producing honey that has gained both national and international recognition. There are more than 3,000,000 hives in the country, mainly concentrated in Buenos Aires Province (approximately 1,000,000 hives). In recent decades, worrying rates of hive loss have been observed in many countries around the world. In Latin America, the estimated loss of hives is between 13% (Peru and Ecuador) and 53% (Chile). Argentina had annual losses of 34% for the period of October 1, 2016 to October 1, 2017. The causes of these losses are not clear but probably involve multiple stressors that can act simultaneously. One of the main causes of loss of bee colonies worldwide is infestation by the ectoparasitic mite Varroa destructor in combination with viral infections. To date, 10 viruses have been detected that affect honey bees (Apis mellifera) in Argentina. Of these, deformed wing virus, sacbrood virus, acute bee paralysis virus, chronic bee paralysis virus, and Israeli acute bee paralysis can be transmitted by mites. Deformed wing virus and the AIK complex are the viruses most often associated with loss of hives worldwide. Considering that bee viruses have been detected in Argentina in several hymenopteran and non-hymenopteran insects, these hosts could act as important natural reservoirs for viruses and play an important role in their dispersal in the environment. Further studies to investigate the different mechanisms by which viruses spread in the environment will enable us to develop various strategies for the control of infected colonies and the spread of viruses in the habitat where they are found.

Respuesta inmunoprotectora inducida por la glicoproteina D recombinante en el modelo de infección respiratoria de ratones BALB/c por alfaherpesvirus equino 1 / Immunoprotective response induced by recombinant glycoprotein D in the BALB/c respiratory mouse model " of Equid alphaherpesvirus 1 infection

Equid alphaherpesvirus 1 (EHV-1) infection causes abortion, respiratory disease, perinatal deaths and neurological disorders in horses. The natural infection and available vaccines provide only partial and short-lived protection against reinfections. In the present study, we analyzed the ability of purified baculovirus-expressed glycoprotein D (gD) administered by different routes to induce protective immunity in BALB/c mice after challenge with the EHV-1 AR8 strain. Clinical signs varied among the different groups of mice immunized by parenteral routes, and, although gD induced a specific serum IgG response, it did not prevent the virus from reaching the lungs. Intranasally immunized mice showed no clinical signs, and virus isolation from lungs, histological lesions and antigen detection by immunohistochemistry were negative. In addition, by this route, gD did not stimulate the production of serum IgG and IgA. However, a specific IgA response in the respiratory tract was confirmed in intranasally immunized mice. Thus, we conclude that the mucosal immune response could reduce the initial viral attachment and prevent the virus from reaching the lungs. Our findings provide additional data to further study new immunization strategies in the natural host.

La infección con alfaherpesvirus equino 1 (EHV-1) causa abortos, enfermedad respiratoria, muertes perinatales y desórdenes neurológicos en equinos. La infección natural y las vacunas disponibles solo proporcionan protección parcial y de corta duración contra las reinfecciones. En el presente estudio se analizó la inducción de inmunidad protectiva de la glicoproteina D (gD) expresada en baculovirus y purificada al ser administrada por diferentes rutas en ratones BALB/c desafiados con la cepa AR8 de EHV-1. Los signos clínicos fueron variables entre los grupos de ratones inmunizados por rutas parenterales y, aunque la gD indujo respuesta especifica de IgG en suero, no logró prevenir la llegada del virus al pulmón. En los ratones inmunizados intranasalmente no se observaron signos clinicos ni lesiones histopatológi-cas, y el aislamiento viral y la detección de antigenos por inmunohistoquímica en pulmón fueron negativos. Además, por esta ruta la gD no estimuló la producción de IgG y de IgA en suero. Sin embargo se confirmó la respuesta de IgA especifica en el tracto respiratorio de ratones inmunizados intranasalmente. Esta respuesta inmune mucosal podría haber reducido la unión inicial del virus a la célula huésped y, de este modo, prevenir la llegada del virus al pulmón. Nuestros hallazgos proporcionan un aporte para continuar estudiando nuevas estrategias de inmunización en el huésped natural.

Immunoprotective response induced by recombinant glycoprotein D in the BALB/c respiratory mouse model of Equid alphaherpesvirus 1 infection.

Equid alphaherpesvirus 1 (EHV-1) infection causes abortion, respiratory disease, perinatal deaths and neurological disorders in horses. The natural infection and available vaccines provide only partial and short-lived protection against reinfections. In the present study, we analyzed the ability of purified baculovirus-expressed glycoprotein D (gD) administered by different routes to induce protective immunity in BALB/c mice after challenge with the EHV-1 AR8 strain. Clinical signs varied among the different groups of mice immunized by parenteral routes, and, although gD induced a specific serum IgG response, it did not prevent the virus from reaching the lungs. Intranasally immunized mice showed no clinical signs, and virus isolation from lungs, histological lesions and antigen detection by immunohistochemistry were negative. In addition, by this route, gD did not stimulate the production of serum IgG and IgA. However, a specific IgA response in the respiratory tract was confirmed in intranasally immunized mice. Thus, we conclude that the mucosal immune response could reduce the initial viral attachment and prevent the virus from reaching the lungs. Our findings provide additional data to further study new immunization strategies in the natural host.