Apis mellifera cellular immune responses in-vitro: Qualitative differences before and after the puppae metamorphosis black box

PEDRO NEGRI; MATIAS DANIEL MAGGI; NATALIA FERNANDEZ; LORENZO LAMATTINA; MARTIN JAVIER EGUARAS

Buenos Aires

Congreso; International Congress on Invertebrate Pathology and Microbial Control 45th Annual Meeting of the Society for Invertebrate Pathology; 2012

Insects have a well developed innate immune system to defend themselves from infectious organisms. Innate immune responses are subdivided into humoral and cellular defences. Most literature is focused on model species like Drosophyla melanogaster, selected Lepidoptera and mosquitoes. The honey bee Apis mellifera (Hymenoptera) is an ideal system for investigating ontogenetic changes in the immune system. It combines holometabolous development within a eusocial caste organization. Most work to date has focussed on the humoral immune response of A. mellifera while very little is known about the cellular immune response of honeybees. The main purpose of this work was to study A. mellifera hemocytic responses before and after the pupae metamorphosis. Haemolymph from the A. mellifera Sppining larvae (SL) and newly emerged workers (W) was used to perform the experiments. Cells that spread upon stimulation with Lipopolysacharide, flagellin, Paenibacillus larvae and contact with a glass surface were considered as immune related hemocytes. Hemocytes were observed using DIC microscopy and time lapse imaging and described in concordance to Strand 2008. Noticeable differences were found between SL and W hemocytes in regard to appearance, size, cell migration and spreading in-vitro. However, SL and W hemocytes described similar encapsulation related behavioural pattern. Previous reports showed quantitative differences between A. mellifera SL and W hemocytes. This work shows qualitative differences and similarities between SP and W. Nevertheless, in-vitro P. larvae phagosytosis is reported in this work. Also, an experimental system for performing in-vitro encapsulation experiments with A. mellifera hemocytes in particular is proposed here.