Immunosenescence in honey bees (Apis mellifera L.) is caused by intrinsic senescence and behavioral physiology

Autor(es)

Lourenco, Anete Pedro ^{[1, 2]} ; Martins, Juliana Ramos ^[1] ; Silva Torres, Fernanda Andrade ^{[3, 1]} ; Mackert, Aline ^{[3, 4]} ; Aguiar, Luiz Roberto ^[1] ; Hartfelder, Klaus ^[5] ; Gentile Bitondi, Marcia Maria ^[3] ; Paulino Simoes, Zila Luz ^[3]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Fac Med Ribeirao Preto, Dept Genet, Ribeirao Preto, SP - Brazil

^[2] Univ Fed Vales Jequitinhonha & Mucuri, Dept Ciencias Biol, Fac Ciencias Biol & Saude, Campus JK, Rodovia MGT 367, Km 583, BR-39100000 Diamantina, MG - Brazil

^[3] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Biol, Ribeirao Preto, SP - Brazil

^[4] Univ Fed Mato Grosso do Sul, Dept Ciencias Ambiente, Campus Pantanal, Corumba, MS - Brazil

^[5] Univ Sao Paulo, Fac Med Ribeirao Preto, Dept Biol Celular & Mol & Bioagentes Patogen, Ribeirao Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Experimental Gerontology; v. 119, p. 174-183, MAY 2019.
• Citações Web of Science: 1

Resumo

Young honey bee workers (0 to 2-3 weeks old) perform tasks inside the colony, including brood care (nursing), whereas older workers undergo foraging tasks during the next 3-4 weeks, when an intrinsic senescence program culminates in worker death. We hypothesized that foragers are less able to react to immune system stimulation than nurse bees and that this difference is due to an inefficient immune response in foragers. To test this hypothesis, we used an experimental design that allowed us to uncouple chronological age and behavior status (nursing/foraging). Worker bees from a normal age demography colony (where workers naturally transit from nursing to foraging tasks as they age) and of a single-cohort colony setup (composed of same-aged workers performing nursing or foraging tasks) were tested for survival and capability of activation of the immune system after bacterial injection. Expression of an antimicrobial peptide gene, defensin-1 (def-1), was used to assess immune system activation. We then checked whether the immune response includes changes in the expression of aging- and behavior-related genes, specifically vitellogenin (vg), juvenile hormone esterase (jhe), and insulin-like peptide-1 (ilp-1). We found a significant difference in survival rate between bees of different ages but carrying out the same tasks. Our results thus indicate that the bees' immune response is negatively affected by intrinsic senescence. Additionally, independent of age, foragers had a shorter lifespan than nurses after bacterial infection, although both were able to induce def-1 transcription. In the normal age demography colony, the immune system activation resulted in a reduction in the expression of vg, jhe and ilp-1 genes in foragers, but not in the nurse bees, demonstrating that age and behavior are both important influences on the bees' immune response. By disentangling the effects of age and behavior in the single-cohort colony, we found that vg, jhe and ilp-1 response to immune system stimulation was independent of behavior. Younger bees were able to mount a stronger immune response than older bees, thus highlighting age as an important factor for immunity. Taken together, our results provide new insights into how age and behavior affect the honey bee's immune response. (AU)

• Processo FAPESP: 05/03302-1 - Hexamerina hex 70c de Apis mellifera: caracterização do cDNA e expressão durante a metamorfose e reprodução
• Beneficiário: Juliana Ramos Martins
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 03/07041-2 - Estudo dos genes codificadores dos peptideos antimicrobianos e de outros genes efetores na resposta imune em apis mellifera.
• Beneficiário: Anete Pedro Lourenço
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 04/00732-2 - Biologia molecular de genes envolvidos no metabolismo do hormonio juvenil em apis mellifera.
• Beneficiário: Aline Mackert dos Santos
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 05/03926-5 - Genômica funcional de Apis mellifera: busca de novos genes e redes funcionais no contexto do desenvolvimento, da diferenciação de castas e da reprodução
• Beneficiário: Zilá Luz Paulino Simões
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 11/03171-5 - Análise causal do desenvolvimento de Apis mellifera: genes reguladores e redes hierárquicas de expressão gênica na especificação de tecidos e órgãos
• Beneficiário: Zilá Luz Paulino Simões
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 03/10581-9 - Clonagem do cDNA do hormônio protoracicotropico (PTTH), estudo de sua expressão e hibridação in situ em rainhas e operárias de Apis melifera
• Beneficiário: Fernanda Andrade Silva Torres
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto