BACKGROUND: Chemokine receptor CCR5, the main HIV-1 coreceptor, is present in the human spermatozoa. This study aimed to investigate (i) whether the percentage of CCR5-positive spermatozoa varies under conditions associated with changes in the membrane architecture, such as capacitation and fixation/permeabilization procedures; (ii) whether there is any relationship between individual variability in sperm CCR5 expression and semen parameters. METHODS AND RESULTS: In cytometric analysis, the percentage of CCR5-positive unfixed spermatozoa varied from approximately 10 to approximately 60%, and it significantly decreased after 5 h capacitation. The percentage of CCR5-positive spermatozoa was increased to more than 90% following fixation and permeabilization, suggesting the existence of large intracellular pools of the receptor. Immunocytochemistry showed positive staining in the anterior region of the sperm head. In ejaculates from male partner of 102 infertile couples, the CCR5 expression rate significantly correlated with sperm count, total sperm number and forward motility, but not with sperm morphology. In stepwise analysis, only forward motility entered into the model; however, this explained only approximately 8% of the variability in CCR5 expression. Interquartile analysis showed significant differences between the first and fourth quartiles of CCR5 expression for all semen parameters, except morphology. CONCLUSIONS: The percentage of CCR5-positive spermatozoa may vary under conditions associated with changes in membrane architecture and spermatozoa showed large intracellular pools of CCR5. A lower expression of CCR5 in asthenozoospermia seems to be suggested; however, it would only partially contribute to the inter-individual variability in the CCR5 expression. A genetic basis can be hypothesized to explain the variability.
BACKGROUND: Chemokine receptor CCR5, the main HIV-1 coreceptor, is present in the human spermatozoa. This study aimed to investigate (i) whether the percentage of CCR5-positive spermatozoa varies under conditions associated with changes in the membrane architecture, such as capacitation and fixation/permeabilization procedures; (ii) whether there is any relationship between individual variability in sperm CCR5 expression and semen parameters. METHODS AND RESULTS: In cytometric analysis, the percentage of CCR5-positive unfixed spermatozoa varied from approximately 10 to approximately 60%, and it significantly decreased after 5 h capacitation. The percentage of CCR5-positive spermatozoa was increased to more than 90% following fixation and permeabilization, suggesting the existence of large intracellular pools of the receptor. Immunocytochemistry showed positive staining in the anterior region of the sperm head. In ejaculates from male partner of 102 infertile couples, the CCR5 expression rate significantly correlated with sperm count, total sperm number and forward motility, but not with sperm morphology. In stepwise analysis, only forward motility entered into the model; however, this explained only approximately 8% of the variability in CCR5 expression. Interquartile analysis showed significant differences between the first and fourth quartiles of CCR5 expression for all semen parameters, except morphology. CONCLUSIONS: The percentage of CCR5-positive spermatozoa may vary under conditions associated with changes in membrane architecture and spermatozoa showed large intracellular pools of CCR5. A lower expression of CCR5 in asthenozoospermia seems to be suggested; however, it would only partially contribute to the inter-individual variability in the CCR5 expression. A genetic basis can be hypothesized to explain the variability.
Authors: Sean M Hughes; Claire N Levy; Ronit Katz; Erica M Lokken; Melis N Anahtar; Melissa Barousse Hall; Frideborg Bradley; Philip E Castle; Valerie Cortez; Gustavo F Doncel; Raina Fichorova; Paul L Fidel; Keith R Fowke; Suzanna C Francis; Mimi Ghosh; Loris Y Hwang; Mariel Jais; Vicky Jespers; Vineet Joag; Rupert Kaul; Jordan Kyongo; Timothy Lahey; Huiying Li; Julia Makinde; Lyle R McKinnon; Anna-Barbara Moscicki; Richard M Novak; Mickey V Patel; Intira Sriprasert; Andrea R Thurman; Sergey Yegorov; Nelly Rwamba Mugo; Alison C Roxby; Elizabeth Micks; Florian Hladik Journal: BMC Med Date: 2022-10-05 Impact factor: 11.150