RESUMO
Spontaneous germinal center (GC)-derived B cell lymphomas of SJL mice (RCS) transcribe a 1.8-kb Mtv-29 mRNA under control of the META-env promoter. The encoded vSAg29 stimulates syngeneic Vbeta16(+) CD4(+) T cells, thereby acquiring T cell help necessary for RCS growth. Other strains of B cell lymphoma-prone mice include Mtv29(+) C57L and MA/MyJ, and the Mtv29(-) Mtv7(+)-recombinant inbred strain, SW x J-1. The lymphomas of these mice produce similar mouse mtv-vSAg-encoding mRNA, as characterized by Northern blotting, PCR, and RNase protection. A 1.8-kb mRNA in C57L/J and MA/MyJ lymphomas hybridized with an Mtv29-specific oligonucleotide, whereas SW x J-1 lymphomas produced 1.8-kb transcripts hybridizing with an Mtv7-specific oligonucleotide. Similar META-env-initiated transcripts were absent from LPS-activated B cells from any strain examined but were detected in Peyer's patch RNA from SJL mice. Like typical SJL-derived RCS, all these lymphomas stimulated syngeneic CD4(+) T cells and Vbeta16(+) T hybridoma cells. Immunohistochemical staining of primary tumors showed the presence of peanut agglutinin binding (PNA(+)) highly mitotic lymphoblasts, suggesting their GC derivation. The findings indicate that this novel mRNA for Mtv29 is present in B cell lymphomas from several Mtv29(+) mouse strains. Additionally, this is the first description of the ability of Mtv7 to produce transcripts that are controlled and spliced identically to those of Mtv29 and that are expressed in SW x J-1, I-A(s+), lymphomas that also stimulate Vbeta16(+) T cells. Our results suggest an important role for mouse mtv-vSAgs and Vbeta16 T cell stimulation in the development of GC-derived murine B cell lymphomas.
Assuntos
Genes env/imunologia , Linfoma de Células B/imunologia , Vírus do Tumor Mamário do Camundongo/imunologia , Glicoproteínas de Membrana/imunologia , Infecções por Retroviridae/imunologia , Superantígenos/imunologia , Transcrição Gênica/imunologia , Proteínas do Envelope Viral/imunologia , Animais , Antígenos Virais , Linfócitos B/imunologia , Linfócitos B/metabolismo , Linfócitos B/virologia , Cruzamentos Genéticos , Elementos Facilitadores Genéticos/imunologia , Feminino , Hibridomas , Ativação Linfocitária/genética , Linfoma de Células B/genética , Linfoma de Células B/patologia , Masculino , Vírus do Tumor Mamário do Camundongo/genética , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Endogâmicos NOD , Regiões Promotoras Genéticas/imunologia , Infecções por Retroviridae/genética , Infecções por Retroviridae/patologia , Especificidade da Espécie , Superantígenos/genética , Subpopulações de Linfócitos T/imunologia , Células Tumorais Cultivadas , Proteínas do Envelope Viral/genéticaRESUMO
Little is known about the hormonal control of behavior in marsupials. In the present study, the effects of castration and of testosterone or estradiol replacement therapy on scent marking and precopulatory behavior in male gray short-tailed oppossums (Monodelphis domestica) were examined. It was found that castration resulted in decreases in chest and flank/hip marking displayed by male gray opossums. Testosterone but not estradiol stimulated chest marking in castrates. Males treated with either estradiol or testosterone displayed more flank/hip marking than control males. Highest levels of female aggression toward males were seen when the males had received testosterone treatment. These findings are discussed with respect to similarities and differences between marsupials and eutherians in the neural metabolism of testosterone and the hormonal control of scent marking behavior.