scholarly journals HUBUNGAN ANTARA PERTUMBUHAN DENGAN KEBERADAAN GEN TAHAN PENYAKIT MAJOR HISTOCOMPATIBILITY COMPLEX (MHC) PADA IKAN MAS (Cyprinus carpio)

2016 ◽  
Vol 8 (3) ◽  
pp. 383
Author(s):  
Erma Primanita Hayuningtyas ◽  
Didik Ariyanto ◽  
Khairul Syahputra

Wabah penyakit koi herpes virus (KHV) di Indonesia yang terjadi sejak tahun 2002 merupakan salah satu faktor yang memicu kemerosotan produksi ikan mas budidaya. Pembentukan strain unggul ikan mas tahan KHV dapat menjadi solusi bagi permasalahan tersebut. Pemilihan genotip ikan mas tahan KHV dengan marka molekuler gen major histocompatibility complex class II (MHC-II), khususnya pada alel Cyca DAB 1*05 akan membantu dalam kegiatan seleksi. Penelitian ini bertujuan untuk mengetahui keberadaan gen MHC-II pada populasi dasar G0 ikan mas strain Rajadanu dan hubungannya dengan pertumbuhan (bobot). Metode deteksi keberadaan gen MHC-II pada dua kelompok ikan dengan ukuran berbeda dilakukan dengan teknik PCR. Hubungan antara pertumbuhan ikan mas dengan persentase kemunculan gen MHC-II dianalisis dengan menggunakan program SPSS (Statistical Package for the Social Sciences), sehingga diperoleh korelasi di antara keduanya. Hasil penelitian menunjukkan bahwa hubungan antara pertumbuhan dengan persentase keberadaan gen MHC-II berkorelasi negatif dengan nilai R = -0,742. Hal ini mengindikasikan bahwa semakin cepat pertumbuhan populasi ikan mas maka semakin sedikit persentase individu yang mempunyai gen MHC-II pada setiap populasi ikan mas. Sehingga populasi ikan mas yang pertumbuhannya lambat memiliki tingkat persentase positif MHC-II lebih tinggi (85,71%-100%) dibandingkan populasi ikan mas yang pertumbuhannya cepat (42,86%-85,71%).

2015 ◽  
Vol 10 (4) ◽  
pp. 461
Author(s):  
Didik Ariyanto ◽  
Erma Primanita Hayuningtyas ◽  
Khairul Syahputra

Pengembangan budidaya ikan mas di Indonesia mengalami kendala serius sejak timbulnya penyakit koi herpes virus (KHV) pada tahun 2002. Salah satu pendekatan yang dipakai dalam rangka mengantisipasi penyakit tersebut adalah perbaikan mutu genetik untuk mendapatkan varietas unggul ikan mas tahan KHV melalui seleksi berbantuan marka molekuler (MAS; Marker Assisted selection). Keberadaan gen Major Histocompatibility Complex Class II (MHC-II) diduga berkaitan erat dengan peningkatan daya tahan tubuh ikan mas terhadap penyakit. Di sisi lain, populasi ikan dengan daya tahan terhadap penyakit yang tinggi diduga mempunyai laju pertumbuhan lebih lambat. Penelitian ini bertujuan mengetahui empat hal, yaitu (1) transmisi gen MHC-II dari induk ke anakannya, (2) hubungan antara keberadaan gen MHC-II dengan daya tahan terhadap penyakit, (3) hubungan antara daya tahan terhadap penyakit dengan pertumbuhan, serta (4) pengaruh keberadaan gen MHC-II pada ikan mas terhadap performa benih di lingkungan budidaya. Benih uji diperoleh dari pemijahan induk jantan dan betina ikan mas strain Rajadanu positif MHC-II, serta induk jantan dan betina negatif MHC-II. Analisis gen MHC-II dilakukan menggunakan mesin PCR, analisis daya tahan terhadap penyakit melalui uji tantang secara kohabitasi, dan analisis hubungan daya tahan dengan pertumbuhan dilakukan di kolam air deras di daerah endemik KHV, yaitu di Subang, Jawa Barat selama tiga bulan. Hasil penelitian menunjukkan bahwa populasi ikan mas hasil pemijahan induk jantan dan betina positif MHC-II mempunyai persentase MHC-II sebesar 90%, lebih banyak dibanding populasi hasil pemijahan induk jantan dan betina negatif MHC-II sebesar 40%. Berdasarkan uji tantang, populasi positif MHC-II mempunyai daya tahan terhadap infeksi KHV 8,95% lebih tinggi dibanding populasi negatif MHC-II. Hasil pengujian secara lapang di daerah endemik KHV juga menunjukkan pola hasil yang sama, yaitu populasi positif MHC-II mempunyai sintasan 41,61% lebih baik dibanding populasi negatif MHC-II. Analisis hubungan antara keberadaan gen MHC-II sebagai indikasi ketahanan terhadap penyakit khususnya KHV dengan pertumbuhan di kolam air tenang maupun kolam air deras menunjukkan bahwa populasi ikan mas Rajadanu dengan persentase MHC-II lebih tinggi mempunyai sintasan lebih tinggi tetapi mempunyai laju pertumbuhan lebih lambat.


2010 ◽  
Vol 78 (7) ◽  
pp. 2956-2965 ◽  
Author(s):  
Marlena M. Westcott ◽  
Curtis J. Henry ◽  
Jacqueline E. Amis ◽  
Elizabeth M. Hiltbold

ABSTRACT Dendritic cells (DC) provide a suboptimal niche for the growth of Listeria monocytogenes, a facultative intracellular bacterial pathogen of immunocompromised and pregnant hosts. This is due in part to a failure of large numbers of bacteria to escape to the cytosol, an essential step in the intracellular life cycle that is mediated by listeriolysin O (LLO). Here, we demonstrate that wild-type bacteria that failed to enter the cytosol of bone marrow-derived DC were retained in a LAMP2+ compartment. An isogenic L. monocytogenes strain that produces an LLO protein with reduced pore-forming activity had a severe escape and growth phenotype in DC. Few mutant bacteria entered the cytosol in the first 2 h and were instead found in LAMP2+, major histocompatibility complex class II+ (MHC-II+) H2-DM vesicles characteristic of MHC-II antigen loading compartments (MIIC). In contrast, the mutant had a minor phenotype in bone marrow-derived macrophages (BMM) despite the reduced LLO activity. In the first hour, DC phagosomes acidified to a pH that was, on average, half a point higher than that of BMM phagosomes. Unlike BMM, L. monocytogenes growth in DC was minimal after 5 h, and consequently, DC remained viable and matured late in infection. Taken together, the data are consistent with a model in which phagosomal maturation events associated with the acquisition of MHC-II molecules present a suboptimal environment for L. monocytogenes escape to the DC cytosol, possibly by limiting the activity of LLO. This, in combination with an undefined mechanism that controls bacterial growth late in infection, promotes DC survival during the critical maturation response.


2002 ◽  
Vol 70 (1) ◽  
pp. 380-388 ◽  
Author(s):  
Roman Reddy Ganta ◽  
Melinda J. Wilkerson ◽  
Chuanmin Cheng ◽  
Aaron M. Rokey ◽  
Stephen K. Chapes

ABSTRACT Human monocytic ehrlichiosis is an emerging tick-borne disease caused by the rickettsia Ehrlichia chaffeensis. We investigated the impact of two genes that control macrophage and T-cell function on murine resistance to E. chaffeensis. Congenic pairs of wild-type and toll-like receptor 4 (tlr4)- or major histocompatibility complex class II (MHC-II)-deficient mice were used for these studies. Wild-type mice cleared the infection within 2 weeks, and the response included macrophage activation and the synthesis of E. chaffeensis-specific Th1-type immunoglobulin G response. The absence of a functional tlr4 gene depressed nitric oxide and interleukin 6 secretion by macrophages and resulted in short-term persistent infections for ≥30 days. In the absence of MHC-II alleles, E. chaffeensis infections persisted throughout the entire 3-month evaluation period. Together, these data suggest that macrophage activation and cell-mediated immunity, orchestrated by CD4+ T cells, are critical for conferring resistance to E. chaffeensis.


2000 ◽  
Vol 20 (10) ◽  
pp. 3364-3376 ◽  
Author(s):  
Jean Villard ◽  
Marie Peretti ◽  
Krzysztof Masternak ◽  
Emmanuèle Barras ◽  
Giuseppina Caretti ◽  
...  

ABSTRACT Major histocompatibility complex class II (MHC-II) molecules occupy a pivotal position in the adaptive immune system, and correct regulation of their expression is therefore of critical importance for the control of the immune response. Several regulatory factors essential for the transcription of MHC-II genes have been identified by elucidation of the molecular defects responsible for MHC-II deficiency, a hereditary immunodeficiency disease characterized by regulatory defects abrogating MHC-II expression. Three of these factors, RFX5, RFXAP, and RFXANK, combine to form the RFX complex, a regulatory protein that binds to the X box DNA sequence present in all MHC-II promoters. In this study we have undertaken a dissection of the structure and function of RFX5, the largest subunit of the RFX complex. The results define two distinct domains serving two different essential functions. A highly conserved N-terminal region of RFX5 is required for its association with RFXANK and RFXAP, for assembly of the RFX complex in vivo and in vitro, and for binding of this complex to its X box target site in the MHC-II promoter. This N-terminal region is, however, not sufficient for activation of MHC-II expression. This requires an additional domain within the C-terminal region of RFX5. This C-terminal domain mediates cooperative binding between the RFX complex and NF-Y, a transcription factor binding to the Y box sequence of MHC-II promoters. This provides direct evidence that RFX5-mediated cooperative binding between RFX and NF-Y plays an essential role in the transcriptional activation of MHC-II genes.


2005 ◽  
Vol 25 (19) ◽  
pp. 8607-8618 ◽  
Author(s):  
Michal Krawczyk ◽  
Krzysztof Masternak ◽  
Madeleine Zufferey ◽  
Emmanuèle Barras ◽  
Walter Reith

ABSTRACT The transcription factors RFX and CIITA are major players in regulation of the expression of all classical and nonclassical major histocompatibility complex class II (MHC-II) genes. RFX nucleates the formation of a multiprotein complex, called the MHC-II enhanceosome, on MHC-II promoters. Assembly of this enhanceosome is an obligatory step for recruitment of the coactivator CIITA and thus for activation of MHC-II gene transcription. We have analyzed the function of the ankyrin repeat-containing protein RFXANK, which forms the heterotrimeric RFX complex together with RFX5 and RFXAP. We discovered that ANKRA2, the closest paralogue of RFXANK, can substitute for RFXANK in the activation of MHC-II genes and that this ability is mediated by its ankyrin repeat domain (ARD). This finding provided the basis for a high-resolution structure-function analysis of the ARD of RFXANK, which allowed us to map the RFX5 interaction domain and residues critical for assembly of the RFX complex. We also found that mutations in the fourth ankyrin repeat of RFXANK abolish assembly of the enhanceosome on MHC-II promoters in vivo but not in vitro, suggesting a new role of RFXANK in facilitating promoter occupation in the context of chromatin.


1997 ◽  
Vol 17 (8) ◽  
pp. 4249-4258 ◽  
Author(s):  
S Bontron ◽  
C Ucla ◽  
B Mach ◽  
V Steimle

Major histocompatibility complex class II (MHC-II) molecules present peptide antigens to CD4-positive T cells and are of critical importance for the immune response. The MHC-II transactivator CIITA is essential for all aspects of MHC-II gene expression examined so far and thus constitutes a master regulator of MHC-II expression. In this study, we generated and analyzed mutant CIITA molecules which are able to suppress endogenous MHC-II expression in a dominant negative manner for both constitutive and inducible MHC-II expression. Dominant negative CIITA mutants were generated via specific restriction sites and by functional selection from a library of random N-terminal CIITA deletions. This functional selection strategy was very effective, leading to strong dominant negative CIITA mutants in which the N-terminal acidic and proline/serine/threonine-rich regions were completely deleted. Dominant negative activity is dependent on an intact C terminus. Efficient repression of endogenous MHC-II mRNA levels was quantified by RNase protection analysis. The quantitative effects of various dominant negative CIITA mutants on mRNA expression levels of the different MHC-II isotypes are very similar. The optimized dominant negative CIITA mutants isolated by functional selection should be useful for in vivo repression of MHC-II expression.


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